Virulence Genes

Beef is exposed to contamination at all stages of the production chain, particularly in operations where it is more manipulated and when Good Hygiene Practices are not properly followed. The most relevant pathogen in bovine meat is Salmonella spp, the major causative agent of foodborne diseases in the world. Several studies have shown that Salmonella spp can occur in raw bovine meat at retail level, but little is known about this pathogen in meat produced for export. The present study aimed to determinate the prevalence, antimicrobial susceptibility test, the presence of virulence genes and PFGE macrorestriction profiles of Salmonella spp isolates obtained at different points of the production chain. The survey was conducted in a large slaughterhouse that produces bovine meat for export. Surface samples were collected from 200 animals, at three points of the slaughtering process: hide right (CO), carcass after removal of the hide (CA1) and carcass after cleaning but before chilling (CA2), with a total of 600 samples. The methodology used for detection of Salmonella spp was that recommended by ISO 6579:2002, and results were confirmed by PCR and complete serotyping. The pathogen was found in CO of 31 animals (15.5%), in CA1 of 7 animals (3.5%) and CA2 of 6 animals (3%). The prevalent serovar was S. Infantis (54.5%), followed by S. Enteritidis (13.6%). The presence of virulence genes invA, sitC, spaN, sifA and msgA was investigated by PCR in 44 isolates. All these genes were detected in 59.1% of the isolates, and the others had at least two of these virulence genes. The same isolates were tested for antimicrobial susceptibility using the MIC Evaluator strips (Oxoid) with the antimicrobials ampicillin, cefotaxime, ciprofloxacin, gentamicin, imipenem and tetracycline. All 44 isolates were sensitive to cefotaxime, ciprofloxacin, gentamicin and imipenem, whereas five (11.4%) were resistant to ampicillin and tetracycline simultaneously. The macrorestriction profiles, determined by PFGE, the 44 isolates expressed 26 different genetic profiles, and most profiles (92.3%) contained only one or two isolates. The results indicate that Salmonella spp is present in the studied abattoir. The occurrence of isolates belonging to the same serovar and presenting the same macrorestriction profile in the hides and in the carcasses indicates possible cross contamination during the slaughtering process, strengthening the need of adoption of Good Hygiene Practices to avoid dissemination of the pathogen in beef the production chain.

Dual nano encapsulation of multi-strain probiotic bacteria can enhance their viability within the avian gastrointestinal tract and improve their effectiveness in disease prevention. So that this study spotted the light on the effect of dual nano encapsulated multi strain of probiotics (LEBB-NPs) contained Enterococcus faecium NCTC 7171, Bacillus amyloliquefaciens probiotic CECT 5940, Lacticasei bacillus casei ATTC334 and Bifidobacterium breve JCM1192 on laying performance, egg quality, immune defence, and resistance against Salmonella Typhimurium challenge. A total of 250 Ross 308 laying breeder hens, 20 weeks of age, were randomly allocated into five experimental groups (five replicates per group; 10 hens per replicate). The control group received a basal diet only and was not challenged. Infected control: hens received basal diet only and challenged with S. Typhimurium (1 × 10 6 CFU/hen) at week 34 of age. Groups LEBB-NPsI, LEBB-NPsII and LEBB-NPsIII fed basal diet supplemented with dual nano encapsulated multi strain of probiotics at levels of 1 × 10 6 CFU/kg diet, 1 × 10 8 CFU/kg diet and 1 × 10 10 CFU/kg diet respectively and challenged with Salmonella Typhimurium (1 × 10 6 CFU/hen) at weeks 34 of age. The results indicated that hens receiving LEBB-NPs showed improved egg production and net feed efficiency during the pre-challenge and early laying periods. Additionally, they restored normal egg production performance following the challenge during the mid-laying period. Challenge at 34 weeks with S. Typhimurium had prominently decreased fertility, hatchability and increased egg embryonic death while dietary fortification with LEBB-NPsIII restored these parameters to normal levels. Dietary supplementation with LEBB-NPs enhanced immune defense, as evidenced by increased phagocytic activity, higher levels of IgM, IgG, lysozymes, and complement C3, both before and after the challenge. Furthermore, upregulation of tight junction genes (JAM, MUC-2, ZO-1, ZO-2, OCLN, and cldn-4), anti-inflammatory mediators (IL-4 and IL-10), and avian β defensinins (AvBD6 and AvBD6) expression levels was noticed before and after challenge in all groups fed LEBB-NPs especially in LEBB-NPsIII fed group. Additionally, the expression of inflammatory mediators (IL-1β, IL-6, TNF-α, CCL4, CCL20 and iNos) had been down regulated in groups supplemented by LEBB-NPs compared to infected control group. A noticeable decrease in S. Typhimurium counts was observed at various intervals post-infection in the cecum, feces, liver, ovaries, and eggs in groups fed LEBB-NPs, particularly in the LEBB-NPsIII group. This reduction was accompanied by inhibition of virulence-related genes (HilA and SopD), compared to the infected control group. Overall, the encouraging results obtained from LEBB-NPs suggest their potential application in breeder feed, due to their positive effects on egg production, egg fertility, and hatchability, as well as their stimulatory role in immune defense and resistance to S. Typhimurium challenge.

Background: Because of its high nutritional value, excellent taste, and ease of digestion, fish is one of the most popular foods. However, it also serves as a vehicle for various pathogenic microorganisms, particularly Vibrio species, which pose a risk to public health. Aim: This study targeted studying the prevalence of multidrug-resistant Vibrio species in three marine fish retailed in Egypt. In addition, the antimicrobial activities of lemon juice and sesame oil against Vibrio parahaemolyticus were screened. Methods: For these reasons, this study assessed the prevalence of Vibrio species in marine fish (mullet, brush tooth lizard, and coral fish) that are sold in the local market of Zagazig, Egypt. Additionally, certain virulence factors were detected in the recovered V. parahaemolyticus isolates. The antimicrobial susceptibility of the recovered V. parahaemolyticus isolates was also screened. The antivibrio activities of lemon juice and sesame oil (1% and 2%) were additionally tested. Results: The acquired data showed that the prevalence of Vibrio species was 40% among the tested fish samples. V. parahaemolyticus was isolated at 20.8%. Vibrio fluvialis (8.3%), Vibrio Mimicus (8.3%), and Vibrio alginolyticus (2.5%). The recovered isolates were highly resistant to cefazolin (87.5%), ampicillin (77.1%), cephalothin (68.75%), penicillin, and streptomycin (100%, each). Lemon juice and sesame oil had marked antibacterial activities against V. parahaemolyticus. Conclusion: Fish dipping in lemon juice and sesame oil was an effective way to lower the load of V. parahaemolyticus in fish. In addition, sanitary measures must be implemented to prevent microbial contamination in fish markets and aquatic environments.

RWPE-1 normal prostate cells were tested as an experimental model for adhesion/invasion assays by genotypically and phenotypically characterized community uropathogenic strains of Escherichia coli (UPEC), a frequent cause of urinary tract infections (UTIs) and significant etiologic agent also in bacterial prostatitis. Adhesive ability and strong biofilm production was significantly associated with the bacterial invasive phenotype. Invasive strains derived mainly from male and pediatric patients. This study suggests that such a cell model could usefully integrate other available methods of urovirulence analysis, to deepen knowledge on the bacterial interaction with host cells.

OBJECTIVES: The aim of this study was to determine the susceptibility of Staphylococcus aureus strains to commercial phage preparations. The strains were isolated from clinical patients as well as from nasal mucosa of healthy carriers. BACKGROUND: The elevating number of antibiotic-resistant S. aureus strains present a therapeutic challenge, especially in high-risk patients. One of the promising ways to solve this problem is phage therapy. METHODS: Susceptibility of 111 carrier strains of S. aureus (4 strains were methicillin-resistant; MRSA) and 81 clinical isolates from bloodstream or skin and soft tissue infections (28 were MRSA) to four commercial phage preparations was assessed in vitro by spot assay. The clonality of S. aureus strains was determined by spa typing. RESULTS: Spa typing revealed 97 distinct spa types. A proportion of 73-80 % of the tested S. aureus strains were revealed to have in vitro phage susceptibility, depending on the clonal affi liation of the strains and phage preparation tested. The susceptibility to phage preparations was signifi cantly higher in MRSA strains (p < 0.001). CONCLUSIONS: In vitro results indicate a promising therapeutic potential of the tested commercial antistaphylococcal phage preparations. They could be applied to a broad spectrum of bacterial clones, and have an excellent activity especially against MRSA strains (Tab. 2, Fig. 2, Ref. 43).

Wound infection is frequently reported following snakebite (SB). This study is retrospective. It was conducted in the emergency department and the Intensive Care Unit (ICU) of Cayenne General Hospital between 1 January 2016 and 31 July 2021. We included 172 consecutive patients hospitalized for SB envenoming. All patients were monitored for wound infection. Sixty-three patients received antibiotics at admission (36.6%). The main antibiotic used was amoxicillin–clavulanate (92.1%). Wound infection was recorded in 55 cases (32%). It was 19% in grade 1, 35% in grade 2, and 53% in grade 3. It included abscess (69.1%), necrotizing fasciitis (16.4%), and cellulitis (21.8%). The time from SB to wound infection was 6 days (IQR: 3–8). The main isolated microorganisms were A. hydrophila and M. morganii (37.5% and 18.8% of isolated organisms). Surgery was required in 48 patients (28.1%), and a necrosectomy was performed on 16 of them (33.3%). The independent factors associated with snakebite-a...

Background: Bovine mastitis is a multifactorial and is one of the most challenging disease. It can be caused by many different bacterial species, the most common of which are Staphylococcus species and Streptococcus species. The prevalence of different species varies temporally, geographically and also due to control measures adopted in herds. The present study is on the biofilm forming Streptococcus uberis causing mastitis and the effect of antibiofilm agents on the antimicrobial resistance of the microorganisms. Methods: The isolates were identified by Polymerase chain reaction (PCR). Two antibiofilm agents, resveratrol and ursolic acid (UA) each at two concentrations (30 μg/ml, 100 μg/ml) were used for the study. Biofilm formation and rate of biofilm inhibition was detected using quantitative microtiter plate (MTP) assay and biofilm gene (lux S) was detected using PCR. The isolates treated with antibiofilm agents were subjected to standard disc diffusion test with 7 antibiotics a...

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Background and Aim: The global rise of multidrug-resistant (MDR) Klebsiella pneumoniae poses a serious threat to human and animal health. Close proximity between humans and domestic animals may facilitate zoonotic transmission of MDR strains, underscoring the need for integrated surveillance strategies. This study aimed to investigate the genetic diversity, resistance mechanisms, and virulence gene profiles of K. pneumoniae isolates from domestic animals and humans in Mato Grosso, Brazil, within the One Health framework.

Materials and Methods: A total of 48 clinical isolates (33 from animals and 15 from humans) were analyzed. Identification was confirmed through 16S ribosomal RNA sequencing. Antimicrobial susceptibility was tested using disk diffusion (animal isolates) and minimum inhibitory concentration (human isolates). Resistance (blakpc-2 and blaNDM) and virulence genes (entB, fimH, wabG, ugE, etc.) were detected through polymerase chain reaction. Multilocus sequence typing (MLST) was performed on seven housekeeping genes, and sequence types (STs) were assigned using the Pasteur Institute database (Paris, France).

Results: MDR phenotypes were found in 70.83% (34/48) of isolates – 78.78% of animal and 53% of human samples. Virulence genes were present in 77.08% of isolates; entB was the most prevalent (60.61%). The blakpc-2 gene was found in three human isolates, and blaNDM was found in one human and one bovine isolate. MLST revealed 39 STs, including 9 novel ones. Clonal complexes (CC)258 (human), CC15 (animal), and CC147 (both species) indicated potential interspecies transmission.

Conclusion: This study provides the first comprehensive molecular epidemiological snapshot of K. pneumoniae in domestic animals and humans in Mato Grosso. The discovery of shared clonal complexes and high MDR rates demands urgent cross-sectoral surveillance and control strategies under the One Health approach.


Keywords: blaKPC-2, blaNDM, Brazil, multidrug-resistant Klebsiella pneumonia, multilocus sequence typing, one health, virulence genes, zoonotic transmission.

Background Biopolymers like polyhydroxyalkanoates (PHA) are the best natural macromolecules to use as alternative to the synthetic polymers. Many prokaryotes accumulate PHA as cytoplasmic intracellular granules and their accumulation is triggered by starving conditions. The PHAs are ecofriendly and used to create biodegradable plastics. The microbial synthesized PHA had acquired global importance in industrial and biomedical sectors. Ten different bacterial strains were isolated for the screening of PHA producers from the estuarine region of the Bay of Bengal, Suryalanka in Bapatla. A yellowish slimy circular colony known as M4 is actively growing on selective minimal media and was screened for polymeric granules in its cytoplasm using Sudan Black B and confirmed with the fluorescent dye Nile blue A. All of the isolates were biochemically tested and isolate M4 is the most capable of growing at high NaCl concentrations (3.2 percent) and tests positive for catalase, methyl red. The M4 strain revealed clear hydrolysis of gelatin, starch, and casein. The 16S rRNA sequencing revealed that M4 is 99.72% of identity to Brachybacterium paraconglomeratum LMG 19861(T) in BLAST and the obtained strain was assigned with accession no. MTCC 13074 and deposited in NCBI with accession no. MW899045. The chief cellular fatty acids found in M4 were C14:0, C15:0, C16:0, C18:1cis-9, C18:0, iso-C15: 0, iso-C14: 0, anteiso-C17: 0 and C18:1-7. Crotonic acid formation from M4-PHB extract was detected at 235nm in a UV spectrophotometer. Methanolysis was done, and derivatives of polyhydroxybutyric acid (PHB) in the extract were analyzed using GC-MS. Increasing viscosity was seen in the extracts which confirms the presence of polymer in the extracts. Thermogravimetric analysis was studied to determine the thermal profile of the PHB in the extract of M4. In the study, the selective screening and extraction of ecofriendly PHB from M4 strain was highlighted. Brachybacterium paraconglomeratum is a novel strain showed its uniqueness by producing few monomeric derivatives of PHB. The strain was reporting for the first time as PHA producer. B. paraconglomeratum has promising characteristics according to its metabolic profile. In addition, this study also helps to understand the diversity of bacteria isolated from marine sources.

Non-typhoidal Salmonella (NTS) remains a global pathogen that affects a wide range of animal species. We analyzed a large number of NTS isolates of different host origins, including Salmonella Heidelberg (n = 80, avian), S. Dublin (50, bovine), S. Typhimurium var 5- (n = 40, porcine), S. 4,5,12,:i:- (n = 40, porcine), S. Cerro (n = 16, bovine), and S. Montevideo (n = 14, bovine), using virulence profiling of the bcfC, mgtC, ssaC, invE, pefA, stn, sopB, and siiE virulence-associated genes, a biofilm production assay, pulsed field gel electrophoresis, and the full-length sequencing of the fimA (adhesin) and iroN (receptor) genes. We determined a key amino acid substitution, A169 (i.e., threonine changed to alanine at position 169), in the FimA protein that changed ligand affinity of FimA toward N-acetyl-D-glucosamine. This finding clearly indicates the important role of non-synonymous single nucleotide polymorphism (nsSNPs) in adhesin functionality that may impact the host tropism of ...

ObjectiveDetermine if there is a link between virulence‐associated genes of Haemophilus parasuis and the genotype and serovar of isolates.MethodsIsolates of H. parasuis from 38 farms across six Australian states, representing all serovars present in Australia, were assessed for the presence of virulence‐associated genes (vtaA, hhdBA, fhuA, lsgB and capD). Enterobacterial Repetitive Intergenic Consensus PCR (ERIC‐PCR) and multilocus sequence typing (MLST), together with existing knowledge of the serovar of the isolates and the health status of the source pig, were used to examine 75 Australian isolates of H. parasuis.ResultsAn analysis of the ERIC‐PRC patterns revealed six main clusters. One cluster of 25 isolates lacked virulence‐associated genes and on the basis of serovar and field data, appeared to be mostly non‐pathogenic. Another cluster of five isolates containing most of the virulence‐associated genes appeared to be pathogenic based on the field and serovar data. The remainin...

Infections due to multidrug-resistant (MDR) Enterobacteriaceae are an ongoing global threat in their management. The aim of the study was to investigate the antiimicrobial resistance (AMR) and virulence gene profiles of MDR Gram-negative isolates in Sokoto, north-west Nigeria. Materials and method. A total of 578 clinical samples were collected from patients. Suspected Gram-negative bacteria were isolated from these clinical samples: vaginal swab, pus, stool, blood, wound swab and urine, using Gram-staining and conventional biochemical reactions. These isolates were further identified with an identification kit (Microgen-GN-A), and tested against a panel of 11 antibiotics. A single polymerase chain reaction (PCR) assay targeting 13 virulence gene related to adhesion (fimH, papC, and sfaS), iron chelation (iutA, and fyuA), toxins (astA, stx1, stx2, and eaeA), biofilm (bssS), and serum resistance (traT, iss, and kapsMTII) encoding genes were evaluated. Results. A total of 276 Gram-negative isolates were identified using the Gram stain and biochemical reactions. These organisms were further confirmed with identification kit. Of the 276 isolates, 36 organisms of interest (23 Escherichia coli, 4 Klebsiella pneumoniae and 9 Proteus mirabilis) were identified. Other Gram-negative isolates accounted for the remaining 86.9%. The majority of the isolates were resistant to cefixime (100%) and partially resistant to amikacin (19.4%).The virulence genes bssS (58.3%), fimH (44.4%), and iutA (44.4%) were the most prevalent, whereas kapsMTII (5.6%) and stx2 (2.8%) were least detected, while astA was not detected in any of the isolates. The study elucidated the prevalence of antibiotic resistance and virulence genes in Gram-negative bacteria from clinical isolates in Sokoto, north-western Nigeria. The majority of the isolates were MDR, thereby posing a public health risk.

Background and Aim: Escherichia coli is a prominent zoonotic pathogen with diverse virulence factors and significant antibiotic resistance, particularly in pig farming environments. Pig slaughterhouses are critical points of potential bacterial transmission to humans and the environment. Comprehensive genomic surveillance of E. coli in these settings remains limited in Indonesia. This study aimed to investigate the phylogenetic distribution, virulence gene profiles, pathotypes, and antibiotic resistance characteristics of E. coli isolated from pig slaughterhouses in Banten Province, Indonesia, using whole-genome sequencing.

Materials and Methods: Environmental samples, including effluent and floor swabs (n = 200), were collected from 10 pig slaughterhouses. E. coli isolates were identified and previously characterized for antibiotic resistance. Genomic DNA was extracted and sequenced using the Oxford Nanopore MinION platform. Bioinformatic analyses, including virulence gene detection (VirulenceFinder), phylogenetic reconstruction (RAxML), and phylogroup determination (Clermont method), were conducted to classify isolates based on pathotype and genetic lineage.

Results: Fifty-seven virulence genes were identified, including 46 associated with enteric pathotypes (Enterohemorrhagic E. coli: 35%, enterotoxigenic E. coli: 15%, and enteropathogenic E. coli: 5%) and 15 linked to extraintestinal pathotypes (uropathogenic E. coli: 95%, and neonatal meningitis E. coli: 5%). Phylogenetic analysis revealed five phylogroups - A, B1, D, G, and clade I - with A and B1 predominating. Most isolates (60%) exhibited a single pathotype, while a minority (5%) carried genes from multiple pathotypes. Serotypes O73, O78, and O157 were identified, with O73 being the most prevalent. No strong correlation was observed between phylogenetic clustering and virulence gene pathotype.

Conclusion: The high prevalence of multidrug-resistant E. coli with diverse virulence genes in pig slaughterhouses highlights significant zoonotic and environmental health risks. These findings underscore the need for enhanced hygiene practices, antimicrobial stewardship, and longitudinal genomic surveillance in Indonesian pig production systems.


Keywords: antimicrobial resistance, Escherichia coli, pathotype diversity, phylogenetics, pig slaughterhouses, virulence genes, zoonoses.

Salmonella is one of the most severe pathogens causing diseases in poultry and humans, and several factors could become transmission vectors in the husbandry environment. This study was conducted from April to July 2024 to clarify the prevalence of common Salmonella serovars in chickens and the husbandry environment and their pathogenicity and genetic relationship in small-scale farms in the Mekong Delta, Vietnam. A total of 279 samples were randomly collected from fresh chickens' feces (n = 54), husbandry environment (n=81), and pests (n=144), including rats, geckos, and ants, in four small-scale farms to examine the prevalence of Salmonella spp. By the conventional isolation method, 75 samples were positive for Salmonella, accounting for 26.88%. The prevalence of Salmonella in chicken feces, the environment, and pests were 27.78%, 12.35%, and 34.72%, respectively. Of 75 positive Salmonella isolates, two common serovars were identified, including S. Gallinarum (13.33%) and S. Enteritidis (10.67%); however, S. Pullorum and S. Typhimurium were not detected using PCR. These Salmonella isolates were detected virulent genes by using PCR, and found that these isolates harbored several virulent genes, including InvA (100%), fimA (100%), stn (93.33%), sopB (89.33%), and sodC1 (54.57%). The ERIC-PCR method was used to determine the genetic relationship among Salmonella strains carrying virulent genes present in chickens, environment, and pests in these small-scale farms. The results showed diversity in phenotype and similarity in the genetic relationship (more than 75% similarity) among Salmonella strains isolated from chicken feces and the livestock environment. In conclusion, the study indicated that pathogenic Salmonella serovars could survive and be transmitted among sources, including chickens, the husbandry environment, and pests in small-scale poultry farms in the Mekong Delta.

Escherichia coli (E. coli) strains have been classified into eight distinct phylogenetic clusters as per a novel quadruplex PCR method. However, the exact phylogenetic relationship among these bacterial lineages is still uncertain. The current study employed the Clermont phylotyping method to enhance the understanding of phylogenetic clusters of E. coli and evaluate antibiotic resistance in uropathogenic E. coli (UPEC) strains in Iraq.A total of forty-two UPEC isolates were evaluated for antibiotic susceptibility using a disk diffusion test, while the innovative Clermont phylotyping method was employed for the phylogenetic classification of the isolates.The research results showed that different phylogroups were found at the hospitals in Babylon province, Iraq. Phylogroup B2 was the most common, accounting for 47.61% of the samples. It was followed by Clade I (14.28%), B1 (11.90%), A (9.52%), D (4.76%), C (2.38%), and an unidentified phylogroup (9.52%). Furthermore, 37 (88.09%) and 5 (11.90%) of the 42 uropathogenic E. coli isolates under study exhibited multidrug resistance (MDR) and extensive drug resistance (XDR), respectively.There are many MDR and XDR UPEC isolates within phylogroup B2, as evidenced by the fact that MDR and XDR strains within the group accounted for 17 out of 37 cases (45.24%) and 3 out of a total of 5 cases (60%), respectively. Additionally, two new phylogroups were discovered, called C and clade I, which are connected to cryptic E. coli and E. coli sensu stricto, respectively. Therefore, more research must be done elsewhere to better understand the characteristics of antibiotic resistance as well as the prevalence of various phylogroups in Iraq.

Escherichia coli is the main pathogen responsible for extraintestinal infections. A total of 196 clinical E. coli consecutively isolated during 2016 in Spain (100 from Lucus Augusti hospital in Lugo) and France (96 from Beaujon hospital in Clichy) were characterized. Phylogroups, clonotypes, sequence types (STs), O:H serotypes, virulence factor (VF)-encoding genes and antibiotic resistance were determined. Approximately 10% of the infections were caused by ST131 isolates in both hospitals and approximately 60% of these infections were caused by isolates belonging to only 10 STs (ST10, ST12, ST58, ST69, ST73, ST88, ST95, ST127, ST131, ST141). ST88 isolates were frequent especially in Spain while ST141 isolates significantly predominated in France. The 23 ST131 isolates displayed four clonotypes: CH40-30, CH40-41, CH40-22 and CH40-298. Only 13 (6.6%) isolates were carriers of ESBL enzymes. However, 37.2% of the isolates were multidrug-resistant (MDR). Approximately 40% of the MDR isol...

Salmonella enterica subsp. enterica serovar Enteritidis (Salmonella Enteritidis), a cause of food poisoning in humans was isolated from turkeys slaughtered in Izmir, Turkey. It was identified by classical techniques and polymerase chain reaction (PCR), Its antimicrobial susceptibility was determined, and the common resistance genes in antibiotic-resistant strains were demonstrated by PCR. Of the 587 cloacal swabs, 86 (14.7%) were Salmonella positive and of these, 11 (1.9%) were serovar Enteritidis. Antimicrobial susceptibilities were tested by agar dilution MICs. All strains were susceptible to cefoxitin, ciprofloxacin and amikacin. Of the 11 strains tested 9 (81.8%), 6 (54.6%), 6 (54.6%), and 3 (27.3%) were susceptible to gentamicin, ampicillin, chloramphenicol, and tetracycline respectively. Among 11 S. Enteritidis isolates 2 were susceptible to all antimicrobials tested, and 7 strains were multi-drug resistant. Of 8 tetracycline resistant strains, 5 and 3 carried tet(A), tet(B) g...

Untreatable listeriosis and wastage could be traced to contaminated fruits. This study assessed Listeria spp, antimicrobial resistance and virulence genes in ready-for-sale fruits. Listeria spp was identified in 270 fruits: garden egg (90), tomato (90) and watermelon (90), were purchased from thirty markets, in Southwest Nigeria. Listeria spp were evaluated, identified and sequenced. Antimicrobial sensitivity assay (15 antibiotics), eighteen antimicrobial and nine virulence genes were screened for. Listeria spp 28 (100.00 %) at 66.25 MPN/g comprising of pathogenic (19) (L. monocytogenes 6 (21.43 %), L. ivanovii 5 (17.86 %), L. seegligeri 8 (28.57 %)) and nonpathogenic (9) (L. welshimeri 5 (17.86 %), L. grayi 2 (7.14 %) and L. innocua 1 (3.57 %)) strains were distributed in garden egg 8 (28.57 % at 56.63 MPN/g), tomato 14 (50.00 % at 54.29 MPN/g) and watermelon 6 (21.43 % at 57.00 MPN/g). Carbapenem, chloramphenicol, macrolides, tetracycline and folate resistant Listeria strains with highest prevalence were in fruit from Balogun 9 (60.00 %), Agege 8 (28.57 %) and Lekki 10 (45.45 %) in Lagos state. Virulent L. strains had five L. monocytogenes, two L. ivanovii, eight L. seegligeri, five L. welshimeri, two L. innocua and eight L. grayi in fruit from Lagos, Osun and Ondo States respectively. Listeria monocytogenes, L. ivanovii and L. seegligeri in fruit from Lagos State had prfA, plcA and plcB genes. Fruits could thereby be versatile route for various diverse virulent-resistant Listeria strains that could cause constant listeriosis and spoilage. However, there is need for more enforced, good and healthy handling of fruits on farms and in markets.

Background and Aim: Salmonella contamination in eggs poses a significant public health risk, particularly in alternative egg production systems where contamination and antimicrobial resistance remain underexplored. This study aimed to determine the occurrence of Salmonella contamination in three different egg production systems in Phayao, Thailand, and analyze serovar diversity, antimicrobial resistance, virulence genes, and genetic profiles.

Materials and Methods: A total of 750 eggs were sampled from cage, free-range, and organic egg production systems, purchased from supermarkets in Phayao Province. Eggshells and contents were separately analyzed using conventional microbiological methods to isolate Salmonella. Phenotypic identification, serotyping, and antimicrobial susceptibility testing were performed. Genotypic characterization, including virulence and antimicrobial resistance gene detection, was conducted using polymerase chain reaction. Multilocus sequence typing (MLST) was employed to determine genetic diversity.

Results: Salmonella contamination was detected in three eggshell samples (0.4%), with one positive sample from each production system. The identified serovars were Salmonella Mbandaka (cage eggs), Salmonella Corvallis (free-range eggs), and Salmonella Cerro (organic eggs). Antimicrobial resistance was observed in only one isolate, S. Mbandaka, which exhibited resistance to sulfamethoxazole/trimethoprim and carried the sul1 and sul2 genes. All Salmonella isolates harbored virulence genes (invA, sopB, and stn). MLST analysis identified three distinct sequence types (ST413, ST1541, and ST1593) corresponding to the detected serovars.

Conclusion: This study demonstrates a low occurrence of Salmonella contamination in eggshells across different production systems, with no contamination detected in egg contents. The presence of distinct serovars and genetic types suggests varying contamination sources. Although antimicrobial resistance was minimal, the presence of virulence genes in all isolates highlights the potential risk of infection. Continuous monitoring and improved biosecurity measures in egg production and distribution are recommended to enhance food safety and public health.

Keywords: antimicrobial resistance, eggs, food safety, multilocus sequence typing, Salmonella, virulence genes.

Background and Aim: Salmonella contamination in eggs poses a significant public health risk, particularly in alternative egg production systems where contamination and antimicrobial resistance remain underexplored. This study aimed to determine the occurrence of Salmonella contamination in three different egg production systems in Phayao, Thailand, and analyze serovar diversity, antimicrobial resistance, virulence genes, and genetic profiles. A total of 750 eggs were sampled from cage, free-range, and organic egg production systems, purchased from supermarkets in Phayao Province. Eggshells and contents were separately analyzed using conventional microbiological methods to isolate Salmonella. Phenotypic identification, serotyping, and antimicrobial susceptibility testing were performed. Genotypic characterization, including virulence and antimicrobial resistance gene detection, was conducted using polymerase chain reaction. Multilocus sequence typing (MLST) was employed to determine genetic diversity. Results: Salmonella contamination was detected in three eggshell samples (0.4%), with one positive sample from each production system. The identified serovars were Salmonella Mbandaka (cage eggs), Salmonella Corvallis (free-range eggs), and Salmonella Cerro (organic eggs). Antimicrobial resistance was observed in only one isolate, S. Mbandaka, which exhibited resistance to sulfamethoxazole/trimethoprim and carried the sul1 and sul2 genes. All Salmonella isolates harbored virulence genes (invA, sopB, and stn). MLST analysis identified three distinct sequence types (ST413, ST1541, and ST1593) corresponding to the detected serovars. This study demonstrates a low occurrence of Salmonella contamination in eggshells across different production systems, with no contamination detected in egg contents. The presence of distinct serovars and genetic types suggests varying contamination sources. Although antimicrobial resistance was minimal, the presence of virulence genes in all isolates highlights the potential risk of infection. Continuous monitoring and improved biosecurity measures in egg production and distribution are recommended to enhance food safety and public health.

IJMM 2018; 11(6): 178-183 Background and Aims: Klebsiella pneumoniae that causes bloodstream and urinary tract infections has several virulence factors encoding genes. Factors like the ability of adherence to the host cell surface, presence of sidrophore receptors and regulation of mucoid phenotype are the common virulence ones involved in the pathogenesis of K. pneumoniae. The aim of this study was to determine the frequency of virulence factor encoding genes in K. pneumoniae isolates, collected from hospitalized patients by Multiplex PCR.

Background and Objective: Uropathogenic strains of Escherichia coli (UPEC) are the most common cause of urinary tract infections. UPEC strains possess an arsenal of virulence factors including fimH, iucD, iroN and hlyA which increase their ability to cause urinary tract infections. This study was done to determine the relationship between phylogenetic group and distribution of virulence genes of Escherichia coli isolated from patients with urinary tract infection. Methods: This descriptive -analytic study was performed on 100 isolates Escherichia coli which collected from patients with UTIs. DNA was extracted from all isolates by the boiling method and subsequently DNA was used to determine the presence of genes encoding virulence factors by Multiplex-PCR. In addition, determination of phylogenetic group, A, B1, B2 and D, was performed by determination of present or absent of of yjaA and chuA genes and DNA fragment TSPE4.C2 using Triple-PCR. The frequency of virulence factors, fimH, iucD, iroN and hlyA were 95%, 69%, 29% and 32%, respectively. In all isolates, the frequency of phylogeny of groups A, B1, B2 and D were 17%, 6%, 55% and 22%, respectively. A significant correlation was found between the presence of virulence encoding genes and the B2 phylogenetic group (P<0.05). Virulence genes were common in phylogenetic group B2 isolates among all phylogenetic groups.

Background: The ability of adherence to the host cell surface, present of sidrophore receptors and α-hemolysin (hlyA) are common virulence attributes produced by Escherichia coli that enhances virulence in a number of clinical infections. It has been revealed that E. coli strains that infect uro-genital tracts have different virulence factors. This study was aimed to determine the prevalence of genes encoding virulence factors in cervico-vaginal pathogenic E. coli isolated from women attending Gynecology clinics in Zabol-Iran. Materials and Methods: In this study, 380 cervico-vaginal swabs were obtained from patients with genital tract infections referred to Gynecology clinics in Zabol-Iran during the period (from January to July 2013). A total 132 E. coli isolates were confirmed by conventional biochemical tests. DNA was extracted from all isolates by the boiling method and then DNA was used to determine the presence and prevalence of selected virulence genes including hlyA, iroN, ...

Listeria monocytogenes is a food-borne pathogen able to survive and grow in different environments including food processing plants where it can persist for month or years. In the present study the discriminatory power of Whole Genome Sequencing (WGS)-based analysis (cgMLST) was compared to that of molecular typing methods on 34 L. monocytogenes isolates collected over one year in the same rabbit meat processing plant and belonging to three genotypes (ST14, ST121, ST224). Each genotype included isolates indistinguishable by standard molecular typing methods. The virulence potential of all isolates was assessed by Multi Virulence-Locus Sequence Typing (MVLST) and the investigation of a representative database of virulence determinant genes. The whole genome of each isolate was sequenced on a MiSeq platform. The cgMLST, MVLST, and in silico identification of virulence genes were performed using publicly available tools. Draft genomes included a number of contigs ranging from 13 to 28 ...

Background and Aim: Fowl cholera, caused by multidrug-resistant (MDR) Pasteurella multocida type A, poses a significant threat to chicken production globally. This study investigates the potential of ethanolic extracts from Wild Egyptian Artichoke (WEA) (Cynara cardunculus L. var. sylvestris) to modulate virulence-associated genes and provide an alternative control strategy.

Materials and Methods: A total of 160 tissue samples from diseased chickens were collected and analyzed. Phenotypic, biochemical (via Vitek 2 Compact), and molecular methods were used to identify P. multocida. Polymerase chain reaction (PCR) confirmed the presence of key adhesion and colonization genes (omp87, ptfA, pfhA) in MDR isolates. The antimicrobial efficacy of WEA ethanolic extract was assessed using disk diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays. Gene expression changes were evaluated using quantitative reverse-transcription PCR after treatment with sub-inhibitory extract concentrations.

Results: Eleven isolates (6.9% prevalence) of P. multocida type A were confirmed, with four showing resistance to over five antimicrobial classes. The ethanolic WEA extract demonstrated significant antibacterial activity, with inhibition zones of up to 25 mm, MIC values ranging from 4 to 16 μg/mL, and MBC values between 8 and 32 μg/mL. Gene expression analysis revealed up to threefold downregulation in omp87 (0.28-fold), pfhA (0.25-fold), and ptfA (0.12-fold) after treatment.

Conclusion: The WEA ethanolic extract effectively downregulates critical virulence genes in MDR P. multocida, highlighting its potential as a novel natural agent for controlling fowl cholera in chicken. This study emphasizes the importance of exploring plant-based antimicrobials to combat resistance and improve animal health.

Keywords: fowl cholera, gene expression, multidrug resistance, Pasteurella multocida, virulence genes, wild Egyptian artichoke.

The aim of the research is to develop an effective vaccine against vibriosis. Vibriosis is a bacterial disease caused by Vibrio spp due to the intensive production activity of brackishwater ponds and cage-cultured fish. The pathogenicity study of V alginolyticus ...

Abstract: Vibrio alginolyticus is one of the major disease-causing bacteria in shrimp aquaculture. The widespread use of antibiotics in shrimp aquaculture to treat bacterial diseases has raised concerns about antibiotic resistance. As a result, alternative treatments, such as plant extract phytochemicals are being explored to mitigate these risks. This study aims to identify promising biologically active compounds from garlic (Allium sativum) that can inhibit the virulent protein thermolabile hemolysin of V. alginolyticus, which causes shrimp vibriosis. Various computational approaches, including molecular docking, pharmacokinetic analysis, and molecular dynamics simulation, were conducted to predict the compounds that can inhibit the phospholipase and hemolysis activities of the thermolabile hemolysin protein. Out of thirty-five compounds from A. sativum, protopine (CID 4970), gibberellin A7 (CID 92782), and gibberellic acid (CID 6466) demonstrated the strongest binding affinities, with scores of-9.4,-8.0, and-7.4 kcal/mol, respectively. Pharmacokinetic and toxicity analyses showed favorable drug-like properties for gibberellin A7 and gibberellic acid with no violations. Molecular dynamics simulations demonstrated that gibberellin A7 and gibberellic acid exhibited the highest stability over 100 nanoseconds. The investigation shows that gibberellin A7 and gibberellic acid from A. sativum have the potential to inhibit the virulent activity of thermolabile hemolysin. However, the study needs further in-vitro and in-vivo analysis to test our predicted results.

The main objective of this study was to applying bcfC gene sequence of Salmonella Typhimurium recently isolated from ducks to give insight into the source and origin, molecular epidemiology, disease pattern of Salmonella Typhimurium in Egyptian duck farms. Out of 75 fecal swab samples, 15 (20%) local field isolates were detected and confirmed phenotypically by culturing, gram staining, biochemically and serologically to be Salmonella Typhimurium. The PCR amplification with bcfC gene-specific primers was conducted with genomic DNA, which revealed a product with the approximate size of 467 bp. TheBcfC gene was found in 7 (46.6%) isolates of Salmonella Typhimurium. Phylogenetic and partial gene sequence analysis of bcfC gene of Salmonella Typhimurium showed clear clustering of Egyptian isolates of Salmonella Typhimurium and different Salmonella strains uploaded from GenBank. Sequence identities between the isolated Egyptian strain and different Salmonella Typhimurium strains from GenBa...

Bovine mastitis, a prevalent disease in dairy farms, exerts a profound negative influence on both the health and productivity of dairy cattle, leading to substantial economic losses for the dairy industry. The disease is associated with different bacterial agents, primarily Gram-positive cocci (e.g., Staphylococcus spp., Streptococcus spp.) and Gramnegative bacilli (e.g., Escherichia coli, Klebsiella pneumoniae). These pathogens induce mastitis through diverse mechanisms, intricately linked to the virulence factors they carry. Despite previous research on the virulence factors of mastitis-causing bacteria in dairy cattle, there remains a significant gap in our comprehensive understanding of these factors. To bridge these gaps, this manuscript reviews and compiles research on the virulence factors of these pathogens, focusing on their roles in mammary tissue infection, immune evasion, adherence to mammary epithelial cells, and invasion and colonization of the mammary gland. These processes are analyzed in depth to provide a comprehensive framework to promote a deeper understanding of dairy pathogenic bacteria and their pathogenic mechanisms and to provide new insights into the control of mastitis in dairy cattle.

Klebsiella pneumoniae is widely recognized as an opportunistic pathogen in both hospital and community settings. It is a key member of the ESKAPE group, which comprises priority microorganisms of major concern owing to their antibiotic resistance. The resistance of K. pneumoniae, particularly related to Extended-Spectrum β-Lactamases (ESBLs), poses a significant global public health challenge. The combination of its Multidrug Resistance (MDR) phenotype and various pathogenicity factors increases its potential to cause severe clinical infections. Biofilm formation was assessed via a semiquantitative microtiter technique. We employed various bioinformatics tools to analyze the Antimicrobial Resistance (AMR), virulence factors, plasmid replicons, and genomic diversity of the CRKP isolates. Overall, among the 24 K. pneumoniae isolates, most produced strong biofilms (n = 21), with some exhibiting moderate (n = 1) or weak (n = 2) biofilm production. An alarming level of resistance to multiple classes of antibiotics was correlated with the presence of various resistance genes, including those for β-lactams (bla OXA-48 , bla OXA-181 , bla CTX-M15 , bla TEM and bla SHV), aminoglycosides (aph(6)-Id, aac(3)-IIe, aadA2, ant(3'')-IIa, aph(3')-Ia and aac(6')-Ib-cr), and quinolones (qnrA, qnrB, qnrS, CRP, and emrR). Various efflux pumps, such as KpnGH, oqxAB, acrAB, acrD, and KpnEF, are ubiquitously distributed across MDR K. pneumoniae strains. Several virulenceassociated genes encoding type 1 fimbriae (fimH), type 3 fimbriae (mrkA), efflux pumps (acrAB, oqxAB), enterobactin (entA, entB, fepC), and yersiniabactin (irp1, irp2, ytbA, ybtE, ybtP, ybtQ, ytbT, ytbU, ytbX) have been identified. Genetically, the isolates presented high diversity, with 18 Sequence Types (STs) and an average of 70.1% accessory genes. On the basis of SNP distance and pairwise ANI analysis, the majority of K. pneumoniae isolates were grouped into one clade. The high plasticity of K. pneumoniae in the acquisition of an MDR phenotype, combined with the phenotypic and genotypic factors described in this report, underscores the challenges in achieving effective clinical therapy with the available antibiotics. The findings also emphasize the critical need for the surveillance of multidrug-resistant pathogens in clinical settings in Senegal, as well as the need to evaluate their prevalence, propagation, and impact on patient health outcomes.

Gaining an insight into the mechanism underlying antimicrobial-resistance development in Staphylococcus aureus is crucial for identifying effective antimicrobials. We isolated S. aureus sequence type 72 from a patient in whom the S. aureus infection was highly resistant to various antibiotics and lysostaphin, but no known resistance mechanisms could explain the mechanism of lysostaphin resistance. Genome-sequencing followed by subtractive and functional genomics revealed that serine hydroxymethyltransferase (glyA or shmT gene) plays a key role in lysostaphin resistance. Serine hydroxymethyltransferase (SHMT) is indispensable for the one-carbon metabolism of serine/glycine interconversion and is linked to folate metabolism. Functional studies revealed the involvement of SHMT in lysostaphin resistance, as ΔshmT was susceptible to the lysostaphin, while complementation of the knockout expressing shmT restored resistance against lysostaphin. In addition, the ΔshmT showed reduced virulence under in vitro (mammalian cell lines infection) and in vivo (wax-worm infection) models. The SHMT inhibitor, serine hydroxymethyltransferase inhibitor 1 (SHIN1), protected the 50% of the wax-worm infected with wild type S. aureus. These results suggest SHMT is relevant to the extreme susceptibility to lysostaphin and the host immune system. Thus, the current study established that SHMT plays a key role in lysostaphin resistance development and in determining the virulence potential of multiple drug-resistant S. aureus.

Infections due to Staphylococcus argenteus have been increasingly reported worldwide and the microbe cannot be distinguished from Staphylococcus aureus by standard methods. Its complement of virulence determinants and antibiotic resistance genes remain unclear, and how far these are distinct from those produced by S. aureus remains undetermined. In order to address these uncertainties, we have collected 132 publicly available sequences from fourteen different countries, including the United Kingdom, between 2005 and 2018 to study the global genetic structure of the population. We have compared the genomes for antibiotic resistance genes, virulence determinants and mobile genetic elements such as phages, pathogenicity islands and presence of plasmid groups between different clades. 20% (n = 26) isolates were methicillin resistant harboring a mecA gene and 88% were penicillin resistant, harboring the blaZ gene. ST2250 was identified as the most frequent strain, but ST1223, which was t...

Avian pathogenic Escherichia coli (APEC) is the causative agent of avian colibacillosis, a localised or systemic infection resulting in clinical diseases such as colisepticemia, chronic respiratory disease and swollen-head syndrome. Globally, avian colibacillosis is the leading cause of morbidity and mortality in poultry, and it has been associated with massive economic losses and welfare problems. This organism is of public health significance as APEC is communicable to humans. The diagnosis of avian colibacillosis relies on clinical signs, typical pathological lesions and culture of E. coli from affected tissue(s). Antimicrobial therapy is often used both for treatment and control. Previous overseas studies have characterised APEC and identified virulence genes (VGs) that can be used as molecular markers for the identification of APEC. Little is known about APEC in broiler chickens in Australia. The aim of this thesis was to gain a better understanding of the epidemiology of APEC in Australian broiler flocks and how factors including presence of VGs and phylogenetic group can improve the identification of this pathotype in Australia. Firstly, three faecal DNA extraction methods were evaluated. Faeces were collected from healthy chickens and chickens with colibacillosis from commercial broiler farms in South East Queensland (SEQ). The extracted DNA was screened by a pentaplex-PCR for five APEC-associated VGs (iroN, iutA, iss, hlyF and ompT). DNA extracted from E. coli isolates cultured from the cloaca and organs of the birds were screened using the same PCR. Repeated bead beating plus column elution was the preferred DNA extraction method, as it yielded good PCR quality and adequate quantity DNA. However, identifying APEC by direct detection of the five VGs from the faecal material was not feasible as all of these genes were also detected in all of the birds. However, the VGs were more commonly detected in E. coli isolates cultured from birds with colibacillosis. A cross-sectional study was performed to estimate APEC farm-level prevalence in healthy broiler chickens in SEQ and to identify potential risk factors associated with the carriage of APEC. At the farm-level, all of the 40 farms sampled were positive for APEC, that is at least one bird per farm carried APEC, while the within-farm prevalence was 63% (95% Confidence Interval: 55.8, 70.2). Higher APEC within-farm bird-level prevalence was significantly associated with the usage of well water as a source of drinking water, failure to disinfect the water line after each flock, farm visitors not showering before entering the shed, distances greater than 20 metres between the car park and the poultry shed and the presence of wild birds within 50 metres of the shed. Chlorinating the drinking water combined with automatic water filtration reduced within-farm bird-level APEC prevalence.

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Background: Microbial contamination continues to be one of the leading risks to food safety. Contaminated leafy green vegetables are the primary cause of infection among children, elderly, and immunocompromised people. The purposes of this work were to isolate and identify of Salmonella spp. in fresh leafy vegetables collected from Jeddah Central Market, Jeddah district, western area, kingdom of Saudi Arabia, estimated of the number and percentage of isolated Salmonella spp and determined the antimicrobial susceptibility of the isolated Salmonella spp. Methods: Five-hundred samples were examined for the presence of Salmonella spp, by using standard microbiological and biochemical tests. Further, detection of Salmonella spp. was done by PCR with the primers targeting invA gene, a key factor for entry of Salmonella into epithelial cells. Susceptibility of the isolated Salmonella spp was done toward thirteen different antibiotics. Results: The percentage of isolation of Salmonella spp was 1.2 % (06/500). It was isolated as (0.40%, 02/500) from Basil, (0.20%, 01/500) from Spinach, Rocket, Parsley and Chards. Two isolates (2/6, 33.3%) showed positive Salmonella invA gene (244 bp). All isolated Salmonella showed resistance to Cephalexin (30 µg/disc), Metronidazole (5 µg/disc) and Methicillin (5 µg/disc).

Escherichia coli is a significant foodborne pathogen, frequently linked to hemorrhagic diarrhea, especially in developing nations, where it presents considerable public health concerns. This study was conducted to examine the virulence gene profiles and antibiotic resistance patterns of E. coli strains isolated from piper betel leaves. A total of 100 betel leaf samples, including fresh (n = 60) and ready-to-eat (n = 40) specimens, were collected and tested for the presence of E. coli using standard diagnostic techniques, such as selective culture methods, staining, latex agglutination, and polymerase chain reaction (PCR) assays. Further, the identified E. coli isolates underwent PCR-based testing for virulence genes and disk diffusion assays to assess antibiotic susceptibility. Among the 100 samples screened, 4% (n = 4/100; 95% CI: 1.57–9.84; P = 0.1126) were identified as E. coli O157, and 33% (n = 33/100; 95% CI: 24.56–42.69; P = 0.4011) were classified as non-O157 isolates. The virulence gene stx1 was found in 10.81% of isolates, while stx2, eaeA, and hlyA genes were not detected in any samples. Antibiotic resistance analysis showed that all isolates (100%, 37/37) were resistant to amoxicillin and erythromycin, with 75.68% (28/37) demonstrating resistance to tetracycline. Notably, all isolates were fully susceptible to ceftriaxone and ciprofloxacin. A majority (72.97%, 27/37) of isolates were sensitive to streptomycin, and 67.57% (25/37) were sensitive to gentamicin. Additionally, 86.48% of the E. coli isolates exhibited multidrug resistance (MDR), showing 10 resistance patterns, including 8 MDR patterns. The most common MDR pattern was AMX-TE-E, observed in 56.76% (21/37) of isolates. One isolate demonstrated resistance to six of the eight tested antibiotics across four distinct classes, with the resistance pattern AMX-TE-GEN-S-E-AZM. The MAR indices for E. coli isolates ranged between 0.25 and 0.75. These findings highlight the significant threat posed to global public health by multidrug-resistant shiga toxin-producing E. coli found on piper betel leaves in urban environments.

Escherichia coli is a significant foodborne pathogen, frequently linked to hemorrhagic diarrhea, especially in developing nations, where it presents considerable public health concerns. This study was conducted to examine the virulence gene profiles and antibiotic resistance patterns of E. coli strains isolated from piper betel leaves. A total of 100 betel leaf samples, including fresh (n = 60) and ready-to-eat (n = 40) specimens, were collected and tested for the presence of E. coli using standard diagnostic techniques, such as selective culture methods, staining, latex agglutination, and polymerase chain reaction (PCR) assays. Further, the identified E. coli isolates underwent PCR-based testing for virulence genes and disk diffusion assays to assess antibiotic susceptibility. Among the 100 samples screened, 4% (n = 4/100; 95% CI: 1.57–9.84; P = 0.1126) were identified as E. coli O157, and 33% (n = 33/100; 95% CI: 24.56–42.69; P = 0.4011) were classified as non-O157 isolates. The virulence gene stx1 was found in 10.81% of isolates, while stx2, eaeA, and hlyA genes were not detected in any samples. Antibiotic resistance analysis showed that all isolates (100%, 37/37) were resistant to amoxicillin and erythromycin, with 75.68% (28/37) demonstrating resistance to tetracycline. Notably, all isolates were fully susceptible to ceftriaxone and ciprofloxacin. A majority (72.97%, 27/37) of isolates were sensitive to streptomycin, and 67.57% (25/37) were sensitive to gentamicin. Additionally, 86.48% of the E. coli isolates exhibited multidrug resistance (MDR), showing 10 resistance patterns, including 8 MDR patterns. The most common MDR pattern was AMX-TE-E, observed in 56.76% (21/37) of isolates. One isolate demonstrated resistance to six of the eight tested antibiotics across four distinct classes, with the resistance pattern AMX-TE-GEN-S-E-AZM. The MAR indices for E. coli isolates ranged between 0.25 and 0.75. These findings highlight the significant threat posed to global public health by multidrug-resistant shiga toxin-producing E. coli found on piper betel leaves in urban environments.

Staphylococcus aureus and cystic fibrosis (CF) are closely interlinked. To date, however, the impact of S. aureus culture in CF airways on lung function and disease progression has only been elucidated to a limited degree. This analysis aims to identify bacterial factors associated to clinical deterioration. Data were collected during an observational prospective multi-center study following 195 patients from 17 centers. The average follow-up time was 80 weeks. S. aureus isolates (n = 3180) were scanned for the presence of 25 virulence genes and agr-types using single and multiplex PCR. The presence of specific virulence genes was not associated to clinical deterioration. For the agr-types 1 and 4, however, a link to the subjects’ clinical status became evident. Furthermore, a significant longitudinal decrease in the virulence gene quantity was observed. Analyses of the plasticity of the virulence genes revealed significantly increased plasticity rates in the presence of environment...

Yersinia enterocolitica is associated with human clinical manifestations. In this study, the bioserotype distribution, virulence potential, the antimicrobial susceptibility, and the genomic diversity of Y. enterocolitica isolates recovered from Argentina and Chile were assessed. Eight Chilean and 22 Argentine isolates recovered from human (7) and animal feces (3), foods (18) and wastewater (2) were analyzed. They belonged to the bioserotypes B2 O:9 (9), B1A O:5 (8), B1A O:41,42‐41,43 (8), B4 O:3 (3) and B1A O:7,8‐8‐8,19 (2). Autoagglutination (AA), Ca2+‐dependent growth at 37°C and yadA, inv and yst genes were observed in B2 O:9 and B4 O:3 strains. B1A strains exhibited the genotype yadA‐ inv‐ yst+. All strains were resistant to ampicillin, rifampicin and erythromycin. By XbaI‐PFGE, 11 genomic types (GTs) were demonstrated (D.I. 0.90). The characteristics of these Y. enterocolitica isolates highlight the importance to maintain active surveillance of this enteropathogen in both count...

The intramammary infusion of lactic acid bacteria has recently emerged as a potential new alternative to antibiotics for preventing and treating bovine mastitis. in this study we first assessed in vitro the probiotic potential of Lactococcus lactis LMG 7930. We then evaluated, in two trials, the efficacy and safety of the intramammary infusion of a live overnight culture of L. lactis for the treatment of subclinical and clinical mastitis in lactating ewes. Finally, we in-depth investigated the mammary gland immune response induced by L. lactis intramammary inoculum using the mouse mastitis model. We found that L. lactis showed in vitro probiotic properties. In vivo, L. lactis rapidly activated the mammary innate immune system. This led to a transient clearance of the pathogen in the gland, but also caused both mild and moderate inflammations in ewes. in the mouse mammary gland, L. lactis inoculum caused variable histological features, ranging from undamaged tissue to severe inflammation. in conclusion, our results suggest that L. lactis can act as mastitis-causing pathogens when inoculated at high density into the mammary glands of mammals. The use of bacterial formulations as alternatives for the treatment of mastitis in ruminants remains in need of further experimentation.

Cell phones, smartphones, and tablets are extensively used in social and professional life, so they are frequently exposed to bacteria. The main goal of the present work was to isolate and characterize Staphylococci strains from students’ cell phone mobiles. Subsequently, 24 Staphylococci strains were tested against a wide range of antibiotics, for the distribution of some virulence-related genes and their ability to form biofilm. Staphylococcus spp. were cultured from all studied devices on chromogenic medium and identified using the matrix-assisted laser desorption/ionization (MALDI), time-of-flight (TOF) mass spectrometry (MS) technique (MALDI-TOF-MS). The results obtained showed that S. aureus was the dominant species (19 strains, 79.1%), followed by S. warneri (3 strains, 12.5%), and S. haemolyticus (2 strains, 8.3%). Isolated strains showed high percentages of hydrolytic enzymes production, resistance to many tested antibiotics, and 37.5% expressed the mecA gene. The tested st...

The yeast pathogen Candida glabrata is the second most frequent cause of Candida infections. However, from the phylogenetic point of view, C. glabrata is much closer to Saccharomyces cerevisiae than to Candida albicans. Apparently, this yeast has relatively recently changed its life style and become a successful opportunistic pathogen. Recently, several C. glabrata sister species, among them clinical and environmental isolates, have had their genomes characterized. Also, hundreds of C. glabrata clinical isolates have been characterized for their genomes. These isolates display enormous genomic plasticity. The number and size of chromosomes vary drastically, as well as intra-and interchromosomal segmental duplications occur frequently. The observed genome alterations could affect phenotypic properties and thus help to adapt to the highly variable and harsh habitats this yeast finds in different human patients and their tissues. Further genome sequencing of pathogenic isolates will provide a valuable tool to understand the mechanisms behind genome dynamics and help to elucidate the genes contributing to the virulence potential.

Staphylococcus aureus is recognized worldwide as one of the major agents of dairy cow intra-mammary infections. This microorganism can express a wide spectrum of pathogenic factors used to attach, colonize, invade and infect the host. The present study evaluated 120 isolates from eight different countries that were genotyped by RS-PCR and investigated for 26 different virulence factors to increase the knowledge on the circulating genetic lineages among the cow population with mastitis. New genotypes were observed for South African strains while for all the other countries new variants of existing genotypes were detected. For each country, a specific genotypic pattern was found. Among the virulence factors, fmtB, cna, clfA and leucocidins genes were the most frequent. The sea and sei genes were present in seven out of eight countries; seh showed high frequency in

is recognized worldwide as one of the major agents of dairy cow intra-mammary infections. This microorganism can express a wide spectrum of pathogenic factors used to attach, colonize, invade and infect the host. The present study evaluated 120 isolates from eight different countries that were genotyped by RS-PCR and investigated for 26 different virulence factors to increase the knowledge on the circulating genetic lineages among the cow population with mastitis. New genotypes were observed for South African strains while for all the other countries new variants of existing genotypes were detected. For each country, a specific genotypic pattern was found. Among the virulence factors, , , and leucocidins genes were the most frequent. The and genes were present in seven out of eight countries; showed high frequency in South American countries (Brazil, Colombia, Argentina), while was harboured especially in one Mediterranean country (Tunisia). The , and genes were not detected in any ...

Campylobacter spp. genera is one of the most common causes of microbial enteritis worldwide. This study aimed to find out how common Campylobacter organisms were in raw meat from large livestock in Iran, as well as to determine their antibiotic susceptibility profiles. Several 550 fresh, ready-to-eat meat samples were collected from slaughterhouses, butcher shops, and restaurants in the study region. The samples were collected from cattle (n=138), goats (n=102), camels (n=56), and sheep (n=254). Campylobacter spp. were isolated and identified using normal bacteriological methods and polymerase chain reaction (PCR). Genotyping was performed using PCR to identify virulence genes. The disc diffusion technique was used to determine antibiotic susceptibility. The two Campylobacter spp. were found in 84 (15.27%) of the 550 meat samples tested. Cattle and camel samples accounted for the highest (52.38%) and lowest (3.57%) frequencies of Campylobacter spp., respectively. There were significant differences in the prevalence of Campylobacter spp. in cattle (2=43.04 or OR=7.68, CI=3.40-17.30, P<0.01). Campylobacter jejuni and Campylobacter coli accounted for 82.14% (n=69) of Campylobacter spp. isolated from raw meat. While C. jejuni was found in 39.28% of the samples (n=33), C. coli was observed in 42.85% (n=36). Other Campylobacter spp. formed 17.85 % (n=15) of the samples. The most common genotypes observed in C. jejuni bacteria collected from different types of large animal samples were ciaB (100%) and flaA (100%). On the other hand, virbll (7.69%) was the C. jejuni strain found with the lowest incidence in different large animal samples. The most frequent genotypes found in C. coli bacteria were ciaB (100%) and flaA (100%). C. coli isolates dnaJ (0%), wlaN (0%), virbll (0%), and ceuE (0%) were detected with the lowest frequency in several samples from large livestock. Campylobacter spp. isolated from different sample types and sources were 100% sensitive to aphA-3-1 and GM10. The isolates were reported to be resistant to E15 (76.93%), cmeB (69.24%), aadE1 (69.24%), CIP5 (69.24%), and AM10 (69.24%). According to this study, Campylobacter was found in food from factory farming. Consequently, the disease can be transmitted by eating raw or undercooked meat. Therefore, proper handling and preparation of meat meals, as well as hygiene measures from the slaughterhouse to the retailer, are critical in preventing Campylobacter infections.

Respiratory disease, or snuffling, is a major problem associated with serious economic losses in the rabbit industry. The dis ease in rabbits is a polybacterial infection in nature, resulting from co-infection with more than one bacterial pathogen. To determine the involved bacterial pathogens in respiratory infections in terms of prevalence and pathogenicity, different specimens from rabbits with typical respiratory disorders are subjected to bacteriological examination followed by molecular verification through RT-PCR or PCR then sequencing of the PCR-product. The results identified Mycoplasma sp. as a major partner in mixed infection with virulent strains of P. multocida or S. aureus, suggesting that, initial infection with Mycoplasma sp. creates vulnerability to subsequent infection with P. multocida or S. aureus. Gross and microscopic analysis were also applied to demonstrate lesions accompanied by the detected bacterial pathogens. This study described the prevalence and charac...

The potential pathogenic role of Mycobacterium tuberculosis H37Rv fadD33, a gene encoding an acyl-CoA synthase that is underexpressed in the attenuated strain H37Ra, was investigated. In a first approach, fadD33 was cloned and expressed in strain H37Ra to restore gene expression and fadD33-complemented bacteria were used to investigate whether fadD33 might confer any growth advantage to M. tuberculosis H37Ra in an infection model of BALB/c mice. No differences were found in the growth rates of M. tuberculosis H37Rv, H37Ra and fadD33-complemented H37Ra in the lungs and spleen. In contrast, in the liver, where the attenuated strain H37Ra showed impaired growth compared to the virulent strain H37Rv, complementation of the attenuated strain H37Ra with fadD33 restored bacterial replication. In a further approach, the fadD33 gene of strain H37Rv was disrupted by allelic exchange mutagenesis and the virulence of the mutant strain was tested by mouse infection. It was found that disruption ...