Antibiotic resistance in the environment

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant hospital-acquired pathogen, particularly concerning in burn patients due to its multidrug resistance. This study aimed to assess the antibiotic sensitivity profile and identify the presence of erm genes (ermA, ermB, and ermC) associated with erythromycin resistance in MRSA isolates from burn patients. A total of 80 S. aureus isolates were collected from burn cases, with initial diagnoses performed using conventional culture and microscopic methods. MRSA isolates were confirmed using chromogenic agar media, and antibiotic susceptibility was determined via the disc diffusion method. Polymerase chain reaction (PCR) was employed to detect the erm genes responsible for macrolide resistance. Among 80 samples, 40 were identified as S. aureus, of which 18 were confirmed as MRSA. PCR analysis revealed the prevalence of ermA, ermB, and ermC genes at rates of 12%, 33%, and 11%, respectively. All MRSA isolates exhibited multidrug resistance to antibiotics, highlighting the challenge of treating infections in burn patients. This study underscores the critical need for molecular characterization of MRSA strains to inform effective therapeutic strategies and control their spread in burn wards.

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant hospital-acquired pathogen, particularly concerning in burn patients due to its multidrug resistance. This study aimed to assess the antibiotic sensitivity profile and identify the presence of erm genes (ermA, ermB, and ermC) associated with erythromycin resistance in MRSA isolates from burn patients. A total of 80 S. aureus isolates were collected from burn cases, with initial diagnoses performed using conventional culture and microscopic methods. MRSA isolates were confirmed using chromogenic agar media, and antibiotic susceptibility was determined via the disc diffusion method. Polymerase chain reaction (PCR) was employed to detect the erm genes responsible for macrolide resistance. Among 80 samples, 40 were identified as S. aureus, of which 18 were confirmed as MRSA. PCR analysis revealed the prevalence of ermA, ermB, and ermC genes at rates of 12%, 33%, and 11%, respectively. All MRSA isolates exhibited multidrug resistance to antibiotics, highlighting the challenge of treating infections in burn patients. This study underscores the critical need for molecular characterization of MRSA strains to inform effective therapeutic strategies and control their spread in burn wards.

The aim of this study was to figure the prevalence, phenotypic and genotypic antibiotic resistance (AR) pattern of Staphylococcus aureus isolated from bovine and swine nares. Materials and Methods: Colonies with typical morphology on Baird-Parker agar supplemented with egg-yolk tellurite emulsion were selected and biochemically/genotypically identified as S. aureus. These strains were further subjected to epsilometer test for their sensitivity to various clinically important antibiotics and antibiotic susceptibility testing for amoxicillin/clavulanic acid, and double-disk diffusion testing was performed by the standard disc diffusion method following CLSI guidelines. S. aureus strains were also tested for the presence of AR genes, viz., blaZ, mecA, aacA-aphD, erm (ermA, ermB, ermC), tet (efflux genes tetK and tetL, tetM and tetO of the ribosomal protection family), and vanA. Results: The nasal cavities of 17 out of 47 randomly selected bovine and 20 out of 28 randomly selected swine were positive for S. aureus, representing the prevalence of 36.2% (95% confidence interval [CI]: 22.5-49.9) and 71.4% (95% CI: 54.7-88.1), respectively. Most of the S. aureus strains showed higher resistance to penicillin (94.6%, minimal inhibitory concentration [MIC] ≥1.5 µg/ml) followed by ciprofloxacin (56.7%, MIC ≥32 µg/ml) and tetracycline (18.9%, MIC ≥32 µg/ml). About 10-15% of the strains were resistant to gentamicin (MIC 16 µg/ml) and oxacillin (MIC 6-8 µg/ml). None of the strains were resistant to vancomycin (MIC 0.25-1.5 µg/ml). In this study, 32.4% strains were resistant to three or more than three antibiotics and prevalence of this multi-drug resistant S. aureus was 45% (95% CI: 26.6-63.4) and 17.6% (95% CI: 6.7-28.5) in swine and bovine nasal samples, respectively. Four strains from pigs were borderline oxacillin-resistant S. aureus MIC 6-8 µg/ml, but none were mecA positive. Two of these strains were β-lactamase hyperproducers. Among the resistance genes blaZ, tetK, tetL, tetM, ermB, and aacA-aphD were found. Conclusion: Our results demonstrated the absence of mecA and pvl gene, but the presence of multi-drug resistant S. aureus in the nares of healthy animals which has a potential to spread in a community.

Streptococcosis is a zoonotic bacterial disease in tilapia and other fresh that creates economic losses, caused mainly by Streptococcus agalactiae and Streptococcus iniae. The hazard of the disease is that it may present apparently healthy as well as its presence in culture water. So, this work aimed to detect streptococci in Nile tilapia farms located in Assiut and Minia Governorates, Egypt. Streptococcus agalactiae (42 isolates) and Streptococcus iniae (59 isolates) were identified. Two Streptococcus agalactiae isolates were molecularly confirmed and exhibited resistance to most antibiotics and a multiple antibiotic resistant index of 0.9-1. The identified isolates could not form biofilm. Identification of these hemolytic, resistant Streptococcus poses a potential hazard for human health; hence, alternative antimicrobials should be searched against infections caused by these bacteria.

Lactococcus garvieae is an important pathogen of fish, associated with high rates of mortality and infection recurrence in summer or stressful conditions. Chronic infection and disease recurrence have also been reported to be associated with biofilms. However, the impact of biofilm and planktonic bacterial infection on fish immune responses remains unclear. In this study, de novo sequencing was used to compare differences of the spleen transcriptome in planktonic-and biofilm-infected mullets. Among the 181,024 unigenes obtained, 3,392 unigenes were associated with immune response genes. Comparative analysis of the gene expression between infection with the L. garvieae planktonic type and biofilm type identified a total of 3,120 and 3,489 differentially expressed genes in response to planktonic and biofilm infection, respectively, of which 1,366 and 1,458 genes were upregulated, and 1,754 and 1,458 genes were downregulated, respectively. Gene ontology enrichment analysis of immune genes identified genes involved in the complement system, toll-like receptor signaling, and antigen processing, which were further verified by qPCR. Additionally, genes encoding TLR2, IL-1b, TNF-a, C7, and MHC class II peptides were downregulated in response to biofilm infection. Importantly, the results show that biofilm infection induces a different immune pathway response compared with planktonic bacterial infection and, furthermore, illustrates that the prevention of biofilm formation may be a necessary and new strategy for controlling bacterial infection in aquaculture.

HE plasmid-borne colistin resistance gene mcr-types were formerly recognized as plasmidmediated colistin mechanism among clinical and animal samples Escherichia coli from China and thereafter reported worldwide. The study investigated for screening of plasmid-mediated colistin and carbapenems resistant genes in Escherichia coli isolates from human and poultry origin. After isolation and identification of isolates from clinical specimens and poultry cloacal swab, disc diffusion and broth microdilution method were determined antibiotic susceptibility patterns, phenotypic Extended-Spectrum Beta-lactamase enzymes (ESBL)-production test and phenotypic colistin resistance. Molecular detection by PCR was applied to targeted carbapenems-resistance genes (KPC-2, OXA-48 and NDM-1) and colistin-resistant genes (mcr-1, mcr-2 and mcr-3). The majority of isolates were higher resistance to commonly used antibiotic categories with Multi-Drug Resistance (63 %) and (93 %) of clinical and poultry E coli isolate, respectively. Using broth microdilution (16%) of isolates displayed phenotypic colistin resistance. Human isolates had higher NDM-1 gene (33.3%), while, higher OXA-48 gene (22.2%) was in poultry isolates, and no KPC-2 gene was identified. Only isolates from poultry contained the mcr-1 gene (27.7%), while mcr-2 gene was present only in human isolates (4.7%) and mcr-3 gene in both human (33.3%) and poultry (22.2%) isolates. Negative mcr-1, 2, and 3 isolates expressed high rates of ESBLproduction. The coexistence of (mcr-3 + NDM-1) was frequent, including 10 isolates, and one isolate carried (mcr-2+mcr-3+NDM-1) combination from urine samples. Data of colistin resistance among clinical and poultry isolates in this region is scarce. Identification of colistin and carbapenems-resistance genes via plasmids among those isolates menace and approaches pan-resistance and failure treatment.

Resistant and multi drug resistant bacteria in food animals threaten food security and public health worldwide. Thus, periodic surveillance of antibiotic resistance among bacteria isolated from food animals is recommended. Hence, 50 Escherichia coli strains isolated from 50 pig faecal samples, each from one pig farm in Ashanti region, Ghana were used as indicators of resistance in pigs using eight antibiotics. 72% and 42% of the isolates were resistant and multi drug resistant respectively. Resistance to streptomycin (22%) was highest, followed by amoxicillin (20%), sulphamethoxazole-trimethoprim (10%), tetracycline (8%) and doxycycline (6%); these closely reflected the antibiotic usage patterns of the farmers. Most strains showed multi drug resistance to amoxicillin and streptomycin (26%) and amoxicillin, streptomycin and tetracycline (24%). Multidrug resistance to both tetracycline and sulphamethoxazole-trimethoprim (16%), tetracycline and doxycycline (12%) and streptomycin and no...

A review of the literature was undertaken to delineate the current level and mechanisms of resistance to carbapenems, colistin, and tigecycline in South Africa. Thirty-two English publications and 32 National Institute of Communicable Diseases communiqués identified between early January 2000 and 20 May, 2016 showed substantial reports of NDM (n = 860), OXA-48 (n = 584), VIM (n = 131), and IMP (n = 45) carbapenemases within this period, mainly in Klebsiella pneumoniae (n = 1138), Acinetobacter baumannii (n = 332), Enterobacter cloacae (n = 201), and Serratia marcescens (n = 108). Colistin and tigecycline resistance was prevalent among K. pneumoniae, A. baumannii, S. marcescens, and E. cloacae. The first mcr-1 colistin resistance gene to be detected in South Africa was reported in Escherichia coli from livestock as well as from hospitalized and outpatients. There are increasing reports of NDM and OXA-48 carbapenemases among Enterobacteriaceae and A. baumannii in South Africa. Mcr-1 is now present in South African patients and livestock. Resistance to carbapenems, colistin, and tigecycline restricts infection management options for clinicians.

Resistant and multi drug resistant bacteria in food animals threaten food security and public health worldwide. Thus, periodic surveillance of antibiotic resistance among bacteria isolated from food animals is recommended. Hence, 50 Escherichia coli strains isolated from 50 pig faecal samples, each from one pig farm in Ashanti region, Ghana were used as indicators of resistance in pigs using eight antibiotics. 72% and 42% of the isolates were resistant and multi drug resistant respectively. Resistance to streptomycin (22%) was highest, followed by amoxicillin (20%), sulphamethoxazole-trimethoprim (10%), tetracycline (8%) and doxycycline (6%); these closely reflected the antibiotic usage patterns of the farmers. Most strains showed multi drug resistance to amoxicillin and streptomycin (26%) and amoxicillin, streptomycin and tetracycline (24%). Multidrug resistance to both tetracycline and sulphamethoxazole-trimethoprim (16%), tetracycline and doxycycline (12%) and streptomycin and no...

Bacteria carrying antibiotic resistance genes (ARGs) are naturally prevalent in lotic ecosystems such as rivers. Their ability to spread in anthropogenic waters could lead to the emergence of multidrug-resistant bacteria of clinical importance. For this study, three regions of the Isabela river, an important urban river in the city of Santo Domingo, were evaluated for the presence of ARGs. The Isabela river is surrounded by communities that do not have access to proper sewage systems; furthermore, water from this river is consumed daily for many activities, including recreation and sanitation. To assess the state of antibiotic resistance dissemination in the Isabela river, nine samples were collected from these three bluedistinct sites in June 2019 and isolates obtained from these sites were selected based on resistance to beta-lactams. Physico-chemical and microbiological parameters were in accordance with the Dominican legislation. Matrix-assisted laser desorption ionization-time ...

In the present study, Escherichia coli strains were isolated from water, stool, sputum and urine samples from HIV and AIDS patients attending treatment centers in the Limpopo Province, using standard microbiological procedures and identified by polymerase chain reaction (PCR). Biofilm assay was performed using the Congo red agar and the microtiter plate methods. Beta-lactamase production was tested using the iodometric method, while the antibiotic susceptibility profiles of the organisms were determined by the disc diffusion method. Of the 139 isolates tested, 58 (42%) were biofilm producers with 22 (16%) of these being strong biofilm producers. Antibiotic resistance was common but kanamycin, meropenem and lomefloxacin were the most active with 6.6, 5.8 and 4.3% resistance rates respectively. The rate of biofilm formation was higher among E. coli isolates from water (55.5% p-value=0.011). Antibiotic resistance was higher among biofilm producers compared to non producers particularly for penicillin (93.1%) and cefipime (50.0%). Lomefloxacin appeared to be the most active antibiotic against the biofilm producing strains with 1.7% resistance among the biofilm producers compared to 6.3% among the non-biofilm producers. Beta-lactamase production was higher among isolates from urine samples. This study suggests that E. coli strains that produce biofilm are common in water and urine samples. However, further studies are needed to determine the potential role of water in the production of urinary tract infections (UTIs) in HIV patients.

Carbapenem-resistant Enterobacteriaceae (CRE) have emerged as an urgent threat to public health. This study aimed to determine the occurrence of CRE and the carbapenemase genes in a farrow-to-finish pig farm, and to investigate carriage proportion and maintenance of CRE during the pig production cycle. We conducted a cross-sectional study by collecting 200 rectal swabs from healthy pigs of 5 groups: gilts, sows, piglets, weaners, and fatteners. In the longitudinal study, 20 healthy pigs were followed from 2 to 26 weeks old, and rectal swabs were collected from each pig for 5 times. Samples were screened for CRE using MacConkey agar supplemented with meropenem at 0.5 µg/mL. Identification and antimicrobial susceptibility pattern of the recovered isolates were determined using an automated system. PCR was used to detect carbapenemase genes. The occurrence of Enterobacteriaceae isolates with the carbapenem resistant phenotype and/or harboring the blaOXA-48 gene was 3% (6/200) in the cr...

Lactococcus garvieae is an important pathogen of fish, associated with high rates of mortality and infection recurrence in summer or stressful conditions. Chronic infection and disease recurrence have also been reported to be associated with biofilms. However, the impact of biofilm and planktonic bacterial infection on fish immune responses remains unclear. In this study, de novo sequencing was used to compare differences of the spleen transcriptome in planktonic- and biofilm-infected mullets. Among the 181,024 unigenes obtained, 3,392 unigenes were associated with immune response genes. Comparative analysis of the gene expression between infection with the L. garvieae planktonic type and biofilm type identified a total of 3,120 and 3,489 differentially expressed genes in response to planktonic and biofilm infection, respectively, of which 1,366 and 1,458 genes were upregulated, and 1,754 and 1,458 genes were downregulated, respectively. Gene ontology enrichment analysis of immune g...

Objective We aimed to provide an analysis of A. baumannii complex (ABC) isolated from blood cultures in South Africa. Materials and methods ABC surveillance was conducted from 1 April 2017 to 30 September 2019 at 19 hospital sites from blood cultures of any age and sex. Organism identification was performed using the MALDI-TOF MS and antimicrobial susceptibility testing (AST), MicroScan Walkaway System. We confirmed colistin resistance with Sensititre, FRCOL panel, and selected for whole-genome sequencing. Results During the study period, we identified 4822 cases of ABC, of which 2152 cases were from 19 enhanced surveillance sites were reported during the enhanced surveillance period (1 August 2018 to 30 September 2019). Males accounted for 54% (2611/4822). Of the cases with known age, 41% (1968/4822) were infants (< 1-year-old). Seventy-eight percent (1688/2152) of cases had a known hospital outcome, of which 36% (602/1688) died. HIV status was known for 69% (1168/1688) of cases...

Increasing reliance on antibiotics of last resort to treat the rising numbers of multidrug-resistant bacterial infections in people has focused attention on how shared-use antibiotics are managed and regulated across human and animal health. Discussions at international and national levels have intensified since the identification of new plasmid-mediated genes for colistin resistance in 2016, first in China and subsequently in many other countries, removing the last line of defense against multidrug-resistant Gram-negative bacterial infections with carbapenem resistance. South Africa has reacted to this threat by doing a situational analysis and review of the existing legislation concerning colistin use in animals and people, to inform which course of action to take. The experiences shared in this Personal View outline the process, institution of governance with widespread stakeholder engagement, surveillance, and interventions that South Africa has taken towards optimising the shar...

Increasing reliance on antibiotics of last resort to treat the rising numbers of multidrug-resistant bacterial infections in people has focused attention on how shared-use antibiotics are managed and regulated across human and animal health. Discussions at international and national levels have intensified since the identification of new plasmid-mediated genes for colistin resistance in 2016, first in China and subsequently in many other countries, removing the last line of defense against multidrug-resistant Gram-negative bacterial infections with carbapenem resistance. South Africa has reacted to this threat by doing a situational analysis and review of the existing legislation concerning colistin use in animals and people, to inform which course of action to take. The experiences shared in this Personal View outline the process, institution of governance with widespread stakeholder engagement, surveillance, and interventions that South Africa has taken towards optimising the shar...

Strains 6105 T and 6106, recovered from colonized patients in a hospital in Tel-Aviv, Israel, were compared with currently known species of the genus Citrobacter by a polyphasic taxonomic approach. Strains were characterized by whole-genome sequencing, 16S rRNA and recN gene sequencing, multilocus sequence analysis (MLSA), average nucleotide identity (ANI), Genome-to-Genome Distance Calculator (GGDC), and biochemical tests. The location and genetic surrounding of antibiotic resistance genes were investigated, and antibiotic susceptibility profiles were determined by broth microdilution or agar dilution methods. Phylogenetic analysis based on recN and MLSA revealed that both strains formed a distinct cluster from all currently recognized species. The ANI and GGDC were 90.7% and 54.3% with Citrobacter farmeri, respectively. The ability to metabolize various compounds also differentiated both strains from closely related Citrobacter species. Chromosomes of the isolates contained locus encoding a novel class A β-lactamase (TEL-1; 90.5% amino acid identity with CdiA of Citrobacter koseri) plus a LysR-like transcriptional regulator (TEL-R) and an~25.5-kb mcr-9 mosaic region. The direct mcr-9 context matched with those previously identified in several plasmids and chromosomes of diverse Enterobacteriaceae, yet similarity with the plasmidic loci extended further. Untypeable plasmids, pCTEL-2 (~235 kb) and pCTEL-1 (~114 kb), devoid of resistance genes, were identified in the strains. The isolates were non-susceptible to β-lactams. The name Citrobacter telavivum sp. nov. is proposed, with 6105 T (CECT 9989 T or DSM 110286 T) as the type strain. C. telavivum may represent a bacterial species adapting to hospital settings, able to disseminate and acquire antimicrobial resistance genes.

Environmental pollution and injudicious use of drugs tend to proliferate the phenomenon of reduced efficiency of drugs. The term resistance thus implies decrease responsiveness towards the chemotherapeutic agents and other drugs to which an individual is prior sensitive at recommended dose level. Improper use and unethical implications of antibiotic therapy is also responsible for the same. The present article thus brief about the mechanism of resistance and their outward manifestations in the microorganisms.

Carbapenem-resistant Enterobacteriaceae (CRE) have emerged as an urgent threat to public health. This study aimed to determine the occurrence of CRE and the carbapenemase genes in a farrow-to-finish pig farm, and to investigate carriage proportion and maintenance of CRE during the pig production cycle. We conducted a cross-sectional study by collecting 200 rectal swabs from healthy pigs of 5 groups: gilts, sows, piglets, weaners, and fatteners. In the longitudinal study, 20 healthy pigs were followed from 2 to 26 weeks old, and rectal swabs were collected from each pig for 5 times. Samples were screened for CRE using MacConkey agar supplemented with meropenem at 0.5 µg/mL. Identification and antimicrobial susceptibility pattern of the recovered isolates were determined using an automated system. PCR was used to detect carbapenemase genes. The occurrence of Enterobacteriaceae isolates with the carbapenem resistant phenotype and/or harboring the bla OXA-48 gene was 3% (6/200) in the cross-sectional study. Groups of sows and piglets had the same occurrence rate at 5% (2/40), while weaner and fattener groups had 2.5% (1/40). In the longitudinal study, CRE were not detected in pigs at an early age; however, two isolates were detected at the age of finishing. This study is the first report of Enterobacteriaceae with a carbapenem resistant phenotype and/or carrying blaOXA-48 gene in pigs in Thailand. Finding CRE in pigs at all age categories including finisher in the study farm underscores the need for active monitoring and surveillance studies to determine the occurrence of CRE in pig farms in Thailand.

Numerous previous publications on the detection of bacterial isolates harbouring the mcr-1 gene from animals and humans strongly suggest an underlying route of transmission of colistin resistance via the food chain. The aim of this study was to investigate the presence of colistin-resistant (Col-R) bacteria in Indian food samples and to identify the underlying mechanisms conferring colistin resistance. Methods: Raw food material, including poultry meat, mutton meat, fish, fruit and vegetables, collected from food outlets in Chennai, India, were processed to identify Col-R bacteria using eosin methylene blue agar supplemented with colistin. Colistin minimum inhibitory concentrations (MICs) were determined by the broth microdilution method. PCR for the mcr-1 and mcr-3 genes was performed on Col-R Escherichia coli and Klebsiella pneumoniae isolates. Mutations in the mgrB gene were analysed in K. pneumoniae isolates. One representative mcr-1-positive E. coli was subjected to whole-genome sequencing. Results: Of 110 food samples tested, 51 (46.4%) were positive for non-intrinsic Col-R Gram-negative bacteria. Three E. coli isolates were found to harbour mcr-1, whereas none were positive for mcr-3. Ten K. pneumoniae isolates had alterations in mgrB, with mutations in four and insertional inactivation in six. Conclusion: The presence of Col-R bacteria and the mcr-1 gene in raw food samples further complicates the antimicrobial resistance scenario in India. To the best of our knowledge, this is the first report in the global literature on mgrB mutation and its insertional inactivation conferring Col-R in K. pneumoniae from food samples.

Background Antimicrobial resistance has become one of the most severe global threats to human and veterinary Medicine. colistin is an effective therapeutic agent against multi-drug-resistant pathogens. However, the discovery of transferable plasmids that confer resistance to colistin (mcr-1) has led to challenges in medical science. This study describes the role of wild birds in the harbouring and environmental spread of colistin-resistant bacteria, which could pose a potential hazard to human and animal health. Methods In total, 140 faecal samples from wild birds (migratory and resident birds) were tested. Twenty surface water samples were collected from the area in which wild bird trapping was conducted, and 50 human stool samples were collected from individuals residing near the surface water sources and farm buildings. Isolation and identification of Enterobacteriaceae and Pseudomonas aeruginosa from the different samples were performed using conventional culture techniques and ...

Background Carbapenem-resistant infections in neonates are increasing worldwide. These organisms are associated with poor outcomes because of the severity of the disease, lack of treatment options and impaired immune systems of premature neonates. These infections are associated with significantly higher morbidity, mortality and prolonged hospitalisations, especially in developing countries. Methods A retrospective study was conducted to evaluate the prevalence and clinical outcomes of neonates with Carbapenem-resistant Enterobacteriaceae (CRE) infection over 24 months, from January 2015 to December 2016. All charts for neonates with positive cultures were reviewed, including characteristics of neonates that acquired the infection, possible risk factors and outcomes. Results A total of 32 cases were included with a prevalence of 5/1000 admissions. The mortality rate was 0.6/1000, with case facility rate at 12.5%. Most neonates developed CRE infections within the first 7 days of admi...

Currency is possibly one of the main media transmitting pathogens and drug resistance due to its wide circulation in daily life. In this study, we made a comprehensive characterization of the bacterial community present on banknotes collected from different geographical regions of Hong Kong (HK) by performing in vitro characterization of the bacterial presence and resistome profile, as well as metagenomic analysis including microbial diversity, the prevalence of potential pathogens, the dissemination potential of antibiotic-resistance genes (ARGs), among others. When comparing the bacterial community of HK banknotes with other HK environmental samples, including water and marine sediment, we revealed that HK banknotes cover nearly 50% of total genera found in all the environmental samples, implying that banknotes harbor diverse bacteria originated from a variety of environments. Furthermore, the banknotes have higher abundance of potential pathogenic species (~5 times more) and ARGs...

Multidrug-resistant organisms (MDROs) have significant health implications that either have not been addressed or received only limited attention especially in resource constrained settings such as Africa where access to newer antibiotics that are often costly, is limited. Acquisition of MDROs have been linked with poorer clinical outcomes and prolonged hospitalization. The evolution and spread of MDROs is influenced by factors such as selective pressure exerted by indiscriminate use of antimicrobials in both agriculture and medicine, lack of prescribing skills and training, lack of access to rapid and reliable diagnostics, suboptimal surveillance, as well as poor implementation and adherence to prevention measures. Although reports indicate increased occurrence of MDROs including members of Enterobacteriaceae which are often implicated in bloodstream, urinary tract, abdomen, skin and soft tissue infections, in Africa, major hurdles that continue to hinder the understanding of the degree of impact of AMR are serious data limitation and underreporting. In this review, we sought to address this gap by providing up-to-date data on the epidemiology of MDROs across the continent, including data on their prevalence and current detection and prevention methods.

Aim: The aim of this study was to figure the prevalence, phenotypic and genotypic antibiotic resistance (AR) pattern of Staphylococcus aureus isolated from bovine and swine nares. Materials and Methods: Colonies with typical morphology on Baird-Parker agar supplemented with egg-yolk tellurite emulsion were selected and biochemically/genotypically identified as S. aureus. These strains were further subjected to epsilometer test for their sensitivity to various clinically important antibiotics and antibiotic susceptibility testing for amoxicillin/clavulanic acid, and double-disk diffusion testing was performed by the standard disc diffusion method following CLSI guidelines. S. aureus strains were also tested for the presence of AR genes, viz., blaZ, mecA, aacA-aphD, erm (ermA, ermB, ermC), tet (efflux genes tetK and tetL, tetM and tetO of the ribosomal protection family), and vanA. Results: The nasal cavities of 17 out of 47 randomly selected bovine and 20 out of 28 randomly selected ...

Salmonella typhimurium phage type DT104 has become an important emerging pathogen. Isolates of this phage type often possess resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline (ACSSuT resistance). The mechanism by which DT104 has accumulated resistance genes is of interest, since these genes interfere with treatment of DT104 infections and might be horizontally transferred to other bacteria, even to unrelated organisms. Previously, several laboratories have shown that the antibiotic resistance genes of DT104 are chromosomally encoded and involve integrons. The antibiotic resistance genes conferring the ACSSuT-resistant phenotype have been cloned and sequenced. These genes are grouped within two district integrons and intervening plasmid-derived sequences. This sequence is potentially useful for detection of multiresistant DT104.

Infections with carbapenemase-producing carbapenemresistant Enterobacteriaceae (CP-CRE) are associated with high mortality rates (1). Carbapenemases encoded on plasmids can move between bacterial strains and have the potential to rapidly increase the proportion of Enterobacteriaceae resistant to carbapenems; as such, CP-CRE have been a particular focus of public health response. Although the Enterobacteriaceae family includes approximately 50 recognized genera, surveillance for CP-CRE has focused on the organisms most associated with clinical infections: Klebsiella spp., Enterobacter spp., and Escherichia coli (2,3). CRE from other, less commonly encountered genera (hereafter referred to as less common genera) have generally not been targeted for carbapenemase testing, in part, because some of these organisms possess intrinsic resistance to the carbapenem imipenem and others express species-specific chromosomal carbapenemases. However, these organisms can also harbor plasmid-mediated carbapenemases. This report describes CP-CRE from less common genera identified through reference testing at CDC and surveillance at the Minnesota Department of Health (MDH) Public Health Laboratory. CDC's Clinical and Environmental Microbiology Branch performs molecular testing on submitted CRE to detect Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-β-lactamase (NDM), Verona integron-mediated metallo-β-lactamase (VIM), active-on-imipenem (IMP), and OXA-48-type carbapenemases. During January 1, 2014-May 25, 2017, CDC identified 1,039 CP-CRE, including 63 (6.1%) from the less common genera. Isolates from the less common genera were submitted by 23 states; Iowa (10; 16%) and Pennsylvania (seven; 11%) contributed the most. KPCproducing Citrobacter spp. (27; 42.9%) was the most common organism-mechanism combination identified (Table ). CRE producing a carbapenemase other than KPC are historically uncommon in the United States and often associated with health care exposures outside the United States. Epidemiologic data were available for 20 of 28 patients with non-KPC-CP-CRE from less common genera passively

The present study aims to explore the crisis of antibiotic resistance and discover more about the current challenges related to self-medication. The current challenges related to antibiotic resistance are unique and differ from the challenges of the past since new bacterial pathogens are involved and continue to evolve. Strains with resistance to multiple antibiotic classes have emerged which the discovery of new antibiotics has failed to match. The consequences of antibiotic resistance are grave with mortality and morbidity continually on the rise. This paper also highlights the possible interventions that can be effective at the micro or individual level in the prevention of development of antibiotic resistance.

In vitro synergy and postantibiotic effect of colistin combined with meropenem against Enterobacteriaceae with multiple carbapenem-resistance mechanisms Branka Bedenic*1, Natasa Beader2, Sonja Francula-Zaninovic3, Dijana Varda-Brkic4, Vesna Tripkovic4, Dorotea Šijak5, Marko Čačić6, Ana Benčić5, Amarela Lukić-Grlić7, Ivan Barisic8, Domagoj Slacanac5, Mirna Vranic-Ladavac9, Sanda Sardelic10, Mario Sviben11 1School of Medicine, University of Zagreb, University Hospital Center Zagreb; University Hospital Center Zagreb; Microbiology 2School of Medicine; University Hospital Center Zagreb; Clinical Department for Clinical and Molecular Microbiology 3Medical Center Zagreb 4University Hospital Center Zagreb; Department for Clinical and Molecular Microbiology 5School of Medicine, University of Zagreb 6Hospital Kleve; Cardiology Clinic 7Children's Hospital Zagreb; Microbiology 8Ait Austrian Institute of Technology; Molecular Diagnostics 9Public Health Institute of Istria County; Microbiolo...

Providencia rettgeri is an opportunistic pathogen implicated in various clinical infections. Here, we report the genome sequence of a Providencia rettgeri strain isolated from hospital effluent in South Africa, which harbors the New Delhi metallo-β-lactamase (NDM) variant 18 gene (blaNDM-18). The 4,835,047-bp genome encodes a resistome and virulome that are of cardinal importance to Providencia infections.

The emergence and spread of Carbapenem-resistant Enterobacteriaceae (CRE) is seriously posing threats in effective healthcare delivery. The aim of this study was to ascertain the emergence of CRE at Chukwuemeka Odumegwu Ojukwu University Teaching Hospital (COOUTH) Awka. Biological samples were collected from 153 consenting patient from 5 clinics in the hospital. The isolates were identified using standard microbiological protocols. Susceptibility to meropenem was done using Kirby-Bauer disc diffusion method on Mueller Hinton Agar. A total of 153 patients were recruited in this study. About one half of those from rural, 63.64% from Sub-urban and 42.27% from urban areas had significant E. coli and Klebsiella spp infections. The male: female ratio of the Enterobacteriaceae infection was 1:1. Almost as much inpatient as outpatient study participants had the infections. The infections were observed mostly on participants with lower educational status. The unmarried individuals were most ...

Introductions: Klebsiella sepsis is the most important nosocomial infection in neonates. The objectives of this study were to review an outbreak in a neonatal unit caused by Klebsiella species, to identify the source of the infections, and to identify infection control measures for eradication and prevention of these infections. Methods: The case notes and investigation reports of all sepsis cases admitted in neonatal units of Patan hospital from July to December 2011 caused by Klebsiella species were retrospectively reviewed. The demographic profile, risk factors along with clinical features and management of sepsis were reviewed. Results: Twenty three out of 37 neonatal blood cultures grew Klebsiella species. Thirty one were K. pneumoniae and six K. oxytoca . Seventeen of the 31 (55%) K. pneumoniae isolates were multidrug resistant and extended spectrum beta lactamase producers. Eighteen of 23 (78%) neonates with Klebsiella sepsis died. After extensive cleaning methods and identif...

Background Colistin is regarded as a last-resort antimicrobial against multi-drug resistant Gram-negative bacteria (GNB), therefore the dissemination of colistin resistance in the environment is of great concern. Horizontal transfer of mobile colistin resistance (mcr) genes to potential pathogens poses a serious problem. This study aimed to describe the presence of colistin resistant GNB and mcr genes in river and storm water in regions of the Western Cape. Methods Water samples were collected from three rivers during May 2019 and January 2020 and two storm water samples were collected in November 2019. Colistin resistant GNB were cultured on MacConkey agar containing colistin and identified by MALDI-TOF. Colistin resistance was confirmed using broth microdilution (BMD). mcr-1-5 genes were detected by PCR performed directly on the water samples and on the colistin resistant isolates. mcr functionality was assessed by BMD after cloning the mcr genes into pET-48b(+) and expression in ...

During the post-antibiotic golden age, it has seen a massive antibiotic/antibacterial production and an increase in irrational use of these few existing drugs in the medical and veterinary practice, food industries, tissue cultures, agriculture and commercial ethanol production globally. The irrational drug use has been further exacerbated by the increased marketing and promotion of these drugs by the pharmaceutical companies thus increasing their accessibility in the public and hence their improper use. The lack of production and introduction of the newer and effective antibiotic/antibacterial drugs in clinical practice in the post-antibiotic golden age has seen an increase in the emergence of the resistant pathogenic bacterial infections creating a significant problem in the global health of human kind. The massive productions of the antibiotic/antibacterial drugs have contributed to the poor disposal of these drugs and hence many of them are discharged in various water bodies contributing to the environmental antibiotic/antibacterial drug pollution. In the environment, these drugs exert pressure on the environmental bacteria by destroying useful bacteria that are responsible for the recycling of the organic matter and as well as promoting the selection of the resistant pathogenic bacteria that can spread in human and animal population thus causing an increase in the observed bacterial disease burden and hence a significant global public health problem. The resistant bacterial diseases lead to the high cost, increased occurrence of adverse drug reactions, prolonged hospitalization, the exposure to the second-and third-line drugs like in MDR-TB and XDR-TB that leads to toxicity and deaths as well as the increased poor production in agriculture and animal industry and commercial ethanol production.

Background Plasmid-mediated resistance to the last-resort drugs: carbapenems and colistin is an emerging public health threat. The studies on the prevalence and co-expression of resistant genes among livestock and human pathogens are rare in Nepal. This is the first study in Nepal exploring the prevalence and co-existence of colistin resistance gene, mcr-1 along with carbapenemase resistance gene, OXA-48 in Escherichia coli isolated from poultry and clinical specimens. Methods A total of 240 rectal swabs from chickens of five different poultry farms of Kathmandu valley and 705 mid-stream urine samples from human subjects attending Kantipur Hospital, Kathmandu were collected between August, 2018 and March, 2019. Rectal swabs and urine specimens were cultured. E. coli isolated from the specimens were screened for antimicrobial susceptibility testing (AST) using disk diffusion method’. Minimum inhibitory concentration (MIC) of colistin was determined by agar dilution method using 0.5 µ...

Providencia rettgeri is an opportunistic pathogen implicated in various clinical infections. Here, we report the genome sequence of a Providencia rettgeri strain isolated from hospital effluent in South Africa, which harbors the New Delhi metallo-β-lactamase (NDM) variant 18 gene (blaNDM-18). The 4,835,047-bp genome encodes a resistome and virulome that are of cardinal importance to Providencia infections.

During the post-antibiotic golden age, it has seen a massive antibiotic/antibacterial production and an increase in irrational use of these few existing drugs in the medical and veterinary practice, food industries, tissue cultures, agriculture and commercial ethanol production globally. The irrational drug use has been further exacerbated by the increased marketing and promotion of these drugs by the pharmaceutical companies thus increasing their accessibility in the public and hence their improper use. The lack of production and introduction of the newer and effective antibiotic/antibacterial drugs in clinical practice in the post-antibiotic golden age has seen an increase in the emergence of the resistant pathogenic bacterial infections creating a significant problem in the global health of human kind. The massive productions of the antibiotic/antibacterial drugs have contributed to the poor disposal of these drugs and hence many of them are discharged in various water bodies contributing to the environmental antibiotic/antibacterial drug pollution. In the environment, these drugs exert pressure on the environmental bacteria by destroying useful bacteria that are responsible for the recycling of the organic matter and as well as promoting the selection of the resistant pathogenic bacteria that can spread in human and animal population thus causing an increase in the observed bacterial disease burden and hence a significant global public health problem. The resistant bacterial diseases lead to the high cost, increased occurrence of adverse drug reactions, prolonged hospitalization, the exposure to the second-and third-line drugs like in MDR-TB and XDR-TB that leads to toxicity and deaths as well as the increased poor production in agriculture and animal industry and commercial ethanol production.

Background Plasmid-mediated resistance to the last-resort drugs: carbapenems and colistin is an emerging public health threat. The studies on the prevalence and co-expression of resistant genes among livestock and human pathogens are rare in Nepal. This is the first study in Nepal exploring the prevalence and co-existence of colistin resistance gene, mcr-1 along with carbapenemase resistance gene, OXA-48 in Escherichia coli isolated from poultry and clinical specimens. Methods A total of 240 rectal swabs from chickens of five different poultry farms of Kathmandu valley and 705 mid-stream urine samples from human subjects attending Kantipur Hospital, Kathmandu were collected between August, 2018 and March, 2019. Rectal swabs and urine specimens were cultured. E. coli isolated from the specimens were screened for antimicrobial susceptibility testing (AST) using disk diffusion method’. Minimum inhibitory concentration (MIC) of colistin was determined by agar dilution method using 0.5 µ...

Raoultella ornitholytica, an environmental organism, has only recently been reported as a cause of infections in humans, and is associated mainly with bacteraemia in elderly patients. Carbapenem resistance is unusual in Raoultella spp. We describe the first paediatric case of bla NDM-1 Raoultella ornitholytica bacteraemia in a preterm neonate that developed three days after hospitalisation. This case report discusses a rare organism that had an unexpected susceptibility profile and caused bacteraemia in a neonate. Treatment options are explored.

Superbugs: An Ongoing And Inevitable Battle provides a detailed look at antibiotic resistance, the latest threat to human health aptly described as an arms race between bacteria and the medicine built to stop them. The chapters delve into the evolution of antibiotic resistance, its mechanism of action, treatment and relevance to society.

Salmonella typhimurium phage type DT104 has become an important emerging pathogen. Isolates of this phage type often possess resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline (ACSSuT resistance). The mechanism by which DT104 has accumulated resistance genes is of interest, since these genes interfere with treatment of DT104 infections and might be horizontally transferred to other bacteria, even to unrelated organisms. Previously, several laboratories have shown that the antibiotic resistance genes of DT104 are chromosomally encoded and involve integrons. The antibiotic resistance genes conferring the ACSSuT-resistant phenotype have been cloned and sequenced. These genes are grouped within two district integrons and intervening plasmid-derived sequences. This sequence is potentially useful for detection of multiresistant DT104.

Relative bacterial load as assessed by swabbing of surfaces is used to make critical decisions about safety in medical, food and athletic venues, with little consideration of bacterial attachment features (capsules, pili, flagella), swab type, or adhesive properties of fomites. To consider the impact of these parameters, a known quantity of bacteria with different adhesive specializations was applied to fomites of varying topography and surface energy and retrieved using multiple types of swabs. Swab type affected the total number of bacteria retrieved but had little effect on proportion of bacterial species collected (p = 0.455, by paired t-test). Mutant strains were observed for E. coli to determine contribution of surface features to fomite adhesion. Pili and flagella had greatest impact on retrieval from fomites with varied topography (ANOVA F (44,4) = 6.099; p = 6.0 x 10-4), whereas surface chemistry and capsule chemistry had greatest impact on retrieval of species from fomites of different surface energies (ANOVA F (20,3) = 52.08, p= 1.24 x 10-9). Adhesive properties of additional surface structures may need to be assessed and a more quantifiable study of fomite topography needs to be explored. Ultimately, a paradigm needs to be devised to make accurate comparisons of CFUs retrieved by swabbing surfaces for microbial contaminants.

Background Plasmid-mediated resistance to the last-resort drugs: carbapenems and colistin is an emerging public health threat. The studies on the prevalence and co-expression of resistant genes among livestock and human pathogens are rare in Nepal. This is the first study in Nepal exploring the prevalence and co-existence of colistin resistance gene, mcr-1 along with carbapenemase resistance gene, OXA-48 in Escherichia coli isolated from poultry and clinical specimens. Methods A total of 240 rectal swabs from chickens of five different poultry farms of Kathmandu valley and 705 mid-stream urine samples from human subjects attending Kantipur Hospital, Kathmandu were collected between August, 2018 and March, 2019. Rectal swabs and urine specimens were cultured. E. coli isolated from the specimens were screened for antimicrobial susceptibility testing (AST) using disk diffusion method’. Minimum inhibitory concentration (MIC) of colistin was determined by agar dilution method using 0.5 µ...

In this study, a phylogenic analysis was performed on pathogens previously identified in Hong Kong wet markets' cutting boards. Phylogenetic comparisons were made between phylotypes obtained in this study and environmental and clinical phylotypes for establishing the possible origin of selected bacterial species isolated from wet market cutting board ecosystems. The results reveal a strong relationship between wet market bacterial assemblages and environmental and clinically relevant phylotypes. However, our poor knowledge of potential crosscontamination sources within these wet markets is further exacerbated by failing to determine the exact or presumed origin of its identified pathogens. In this study, several clinically relevant bacterial pathogens such as Klebsiella pneumoniae, Streptococcus suis and Streptococcus porcinus were linked to cutting boards associated with pork; Campylobacter fetus, Staphylococcus aureus, Escherichia coli, and A. caviae in those associated with poultry; and Streptococcus varanii, A. caviae, Vibrio fluvialis, and Vibrio parahaemolyticus in those associated with seafood. Identifying non-foodborne clinically relevant pathogens in wet market cutting boards in this study confirms the need for safety approaches for wet market meat, including cold storage. The presented study justifies the need for future systematic epidemiological studies to determine identified microbial pathogens. Such studies should bring about significant improvements in the management of hygienic practices in Hong Kong's wet markets and work towards a One Health goal by recognizing the importance of wet markets as areas interconnecting food processing with animal and clinical environments.

Background Plasmid-mediated resistance to the last-resort drugs: carbapenems and colistin is an emerging public health threat. The studies on the prevalence and co-expression of resistant genes among livestock and human pathogens are rare in Nepal. This is the first study in Nepal exploring the prevalence and co-existence of colistin resistance gene, mcr-1 along with carbapenemase resistance gene, OXA-48 in Escherichia coli isolated from poultry and clinical specimens. Methods A total of 240 rectal swabs from chickens of five different poultry farms of Kathmandu valley and 705 mid-stream urine samples from human subjects attending Kantipur Hospital, Kathmandu were collected between August, 2018 and March, 2019. Rectal swabs and urine specimens were cultured. E. coli isolated from the specimens were screened for antimicrobial susceptibility testing (AST) using disk diffusion method’. Minimum inhibitory concentration (MIC) of colistin was determined by agar dilution method using 0.5 µ...

Objective: Emergence and dissemination of colistin-resistant (Co-R) bacteria harboring mobile colistin resistance genes pose a threat for treatment of infections caused by multi-drug resistant bacteria. Although the worldwide spread of Co-R bacteria is known, the precise state of Co-R bacterial dissemination in livestock of Andean countries remains unclear. Therefore, we investigated mcr-containing Co-R Escherichia coli dissemination in livestock on smallscale farms in two socioecologically different regions of Ecuador: the Amazonian rainforest and the Pacific Coast. Results: Sixty-six rectal swab samples from 34 pigs and 32 chickens, from five farms in the two regions, were assessed for the dissemination of Co-R E. coli using the selective medium CHROMagar ™ COL-APSE. mcr-containing Co-R E. coli were detected in the specimens at a high rate (47%; 31/66), but the detection rates of the two regions were not statistically different. Both chickens and pigs showed similar detection rates. All Co-R E. coli isolates harbored mcr-1. The minimum inhibitory concentrations of colistin were ≥ 8 mg/L, and 67.7% (21/31) of the Co-R isolates were multi-drug resistant. Pulsed-field gel electrophoresis revealed the limited relation between isolates. Thus, we revealed the high rate of widespread dissemination of Co-R bacteria in livestock regardless of the socioecological conditions in Ecuador.