bacterial colonization

Smoking cessation is the only treatment in patients with chronic obstructive pulmonary disease (COPD) effective in slowing down disease progression. Its effect on airway inflammation in COPD is unknown, although cross-sectional studies suggest ongoing inflammation in ex-smokers. In order to elucidate the effect of smoking cessation on airway inflammation, 28 smokers with COPD (mean age: 55 yrs; forced expiratory volume in one second: 71% predicted) and 25 asymptomatic smokers with normal lung function (aged 50 yrs) were included in a 1-yr smoking cessation programme. Effects of smoking cessation on airway inflammation were investigated in bronchial biopsies (baseline, 12 months) and sputum samples (baseline, 2, 6 and 12 months). In the 12 candidates with COPD who successfully ceased smoking, airway inflammation persisted in bronchial biopsies, while the number of sputum neutrophils, lymphocytes, interleukin (IL)-8 and eosinophilic-cationic-protein levels significantly increased at 12 months. In the 16 asymptomatic smokers who successfully quitted, inflammation significantly reduced (i.e. number of sputum macrophages, percentage of eosinophils and IL-8 levels) or did not change. The current authors suggest that the observed persistent airway inflammation in patients with chronic obstructive pulmonary disease is related to repair of tissue damage in the airways. It remains to be elucidated whether this reflects a beneficial or detrimental effect.

AimTo compare the health of the soft tissues towards zirconia and titanium abutments in man, as observed using histological data.Material and MethodsTwenty patients received two mandibular implants with either a zirconia or titanium abutment (split mouth study design, left‐right randomization). After 3 months soft tissue biopsies were prepared for histological evaluation. They were subjected to blind evaluation. The number of blood vessels per surface unit and an inflammation grading scale score ranging from 1 to 4 were determined.ResultsPaired samples from 17 patients were suitable for analysis, 3 with unsevered implant‐abutment connections and 14 solely containing soft tissue. All showed a well‐keratinized stratified squamous epithelium which was continuous with the barrier (junctional) epithelium that faced the abutment surface. The normal epithelial build‐up could be recognized with little signs of inflammation. No statistically significant difference in tissues adjacent to zirc...

The colonization of surfaces by bacteria is a widespread phenomenon with consequences on environmental processes and human health. While much is known about the molecular mechanisms of surface colonization, the influence of the physical environment remains poorly understood. Here we show that the colonization of non-planar surfaces by motile bacteria is largely controlled by flow. Using microfluidic experiments with Pseudomonas aeruginosa and Escherichia coli, we demonstrate that the velocity gradients created by a curved surface drive preferential attachment to specific regions of the collecting surface, namely the leeward side of cylinders and immediately downstream of apexes on corrugated surfaces, in stark contrast to where nonmotile cells attach. Attachment location and rate depend on the local hydrodynamics and, as revealed by a mathematical model benchmarked on the observations, on cell morphology and swimming traits. These results highlight the importance of flow on the magnitude and location of bacterial colonization of surfaces.

This work aimed to characterize the surface properties of Staphylococcus carnosus and the influence of different media on their ability to adhere and grow on industrial supports. As their colonization could be dependant of the strain, the genetic diversity of the strains was studied. The diversity of 13 strains analysed by pulsed-field gel electrophoresis revealed that the S. carnosus strains formed a homogeneous genetic group. Their surface properties, characterized by studying their affinity to solvents, were hydrophilic with a strong negative surface charge. The S. carnosus strain CIT 833 hardly adhered to polytetrafluoroethylene (PTFE) and stainless steel chips. Tryptic soy broth (TSB) was the most favourable medium for growth on stainless steel support while TSB/NaCl was better for growth on PTFE. Scanning electron microscopy (SEM) showed that this strain weakly colonized both supports and did not form cell aggregates. Indeed, the strain did not synthesize polysaccharides. These results showed that S. carnosus adhered on different abiotic surfaces which are used in food factories but was not able to accumulate on these surfaces. The inability of S. carnosus to form biofilm could explain why S. carnosus is rarely isolated in meat processing environment.

Although mucin O-glycosylation of sputum from individuals suffering from cystic fibrosis (CF) is known to be altered relative to their unaffected counterparts, protein N-glycosylation of CF sputum remains structurally and functionally under-characterized. We report the first N-glycome of soluble proteins in sputum derived from five CF patients, two pathogen-free and two pathogen-infected/colonized non-CF individuals suffering from other pulmonary conditions. N-Glycans were profiled using porous graphitized carbon-liquid chromatography-negative ion-tandem mass spectrometry following enzymatic release from sputum proteins. The composition, topology and linkage isomers of 68 N-glycans were characterized and relatively quantified. Recurring structural features in all sputum N-glycomes were terminal α2,6-sialylation, α1,6-core fucosylation, β1,4-bisecting GlcNAcylation and compositions indicating paucimannosylation. Despite covering different genotypes, age, gender and microbial flora, t...

Opportunistic infections due microorganisms particularly bacteria have posed a threat and thus an addition burden on the management of human immunodeficiency virus (HIV) infections worldwide. The high prevalence of bacterial pathogens and the emergence of multiple drug resistance among such bacteria call for serious concern. Bacteriological examination of 320 women attending HIV clinics was carried out using standard microbiological techniques. The antimicrobial susceptibility testing was carried out by the disc diffusion technique by Bauer and CLSI. Of the 320 women, 200 (62.5%) had bacteria, 120 women were confirmed as HIV positive. Ninety (75%) of these women had both HIV-1 and HIV-2, twenty (16.7%) had only HIV-1 and 10 (8.3%) had only HIV-2. Staphylococcus aureus and Escherichia coli were the predominant bacteria. Antibiogram of the bacterial isolates determined by using the Kirby Bauer disk diffusion showed that most of them were susceptible to augmentin, gentamicin, peflacin, ciprofloxacin, ofloxacin and amoxicillin but were highly resistant to commonly used, over-the-counter drugs like chloramphenicol, tetracycline and streptomycin. This thus poses additional burden on the healthcare system in its attempt to manage HIV using antiretroviral drugs among other methods, along with immunity enhancing drugs while the search for HIV vaccines still continues.

The mechanisms governing the epidemiology dynamics and success determinants of a specific healthcare-associated methicillin-resistant S. aureus (HA-MRSA) clone in hospital settings are still unclear. Important epidemiological changes have occurred in Europe since 2000 that have been related to the appearance of the ST22-IV clone. Between 2006 and 2010, we observed the establishment of the ST22-IV clone displacing the predominant Italian clone, ST228-I, in a large Italian university hospital. To investigate the factors associated with a successful spread of epidemic MRSA clones we studied the biofilm production, the competitive behavior in co-culture, the capacity of invasion of the A549 cells, and the susceptibility to infection in a murine model of acute pneumonia of the two major HA-MRSA clones, ST22-IV and ST228-I. We showed that persistence of ST22-IV is associated with its increased biofilm production and capacity to inhibit the growth of ST228-I in coculture. Compared to ST228-I, ST22-IV had a significantly higher capacity to invade the A549 cells and a higher virulence in a murine model of acute lung infection causing severe inflammation and determining death in all the mice within 60 hours. On the contrary, ST228-I was associated with mice survival and clearance of the infection. ST22-IV, compared with ST228-I, caused a higher number of persistent, long lasting bacteremia. These data suggest that ST22-IV could have exploited its capacity to i) increase its biofilm production over time, ii) maintain its growth kinetics in the presence of a competitor and iii) be particularly invasive and virulent both in vitro and in vivo, to replace other well-established MRSA clones, becoming the predominant European clone.

Bacterial colonization has been already demonstrated in heart valve tissues of patients without cardiovascular infections. However, the evidence of a valvular microbiome is still scarce. The next-generation sequencing method was carried out on 34 specimens of aortic (n = 20) and mitral valves (n = 14) explanted from 34 patients having neither evidence nor history of infectious diseases, particularly infective endocarditis. While no bacteria were demonstrated using standard culture methods, bacterial deoxyribonucleic acid (DNA) sequences were found using next-generation sequencing in 15/34 (44%) cases. Escherichia coli was present in 6 specimens and was the most frequently identified bacterium. There was a trend towards a higher rate of bacterial DNA positivity in specimens of calcific valves than in those of non-calcific valves (10/17 vs 5/17, P = 0.17). Based on a quantitative test, E. coli accounted for 0.7% ± 1% in calcific valvular tissue and 0.3% ± 0.3% in non-calcific valvular...

Objective.To estimate and compare the impact on healthcare costs of 3 alternative strategies for reducing bloodstream infections in the intensive care unit (ICU): methicillin-resistant Staphylococcus aureus (MRSA) nares screening and isolation, targeted decolonization (ie, screening, isolation, and decolonization of MRSA carriers or infections), and universal decolonization (ie, no screening and decolonization of all ICU patients).Design.Cost analysis using decision modeling.Methods.We developed a decision-analysis model to estimate the health care costs of targeted decolonization and universal decolonization strategies compared with a strategy of MRSA nares screening and isolation. Effectiveness estimates were derived from a recent randomized trial of the 3 strategies, and cost estimates were derived from the literature.Results.In the base case, universal decolonization was the dominant strategy and was estimated to have both lower intervention costs and lower total ICU costs than ...

Bacterial colonization in areas of burnt skin and healthy children younger than 15 years, seen COANIQUEM, Santiago, Chile Bacterial colonization in patients with burns skin without infection and outpatient management has been poorly studied. Objective: To quantify and identify the type of bacteria that colonize healthy body areas homologous location of the skin in children from 1 to 15 years, seen COANIQUEM, Santiago, Chile. Per patient, we studied 204 samples from each zone. The isolated microorganisms were S. epidermidis 35, 3%; others Staphylococcus coagulase negative, 25.8%; S. aureus, 4.4%; and S. viridans group 1.4%. In the subgroup of children who had a count between 1 and 1000 cfu, there was a higher proportion of cfu in burned skin healthy skin (p = 0.0359). The association between depth of the lesion and the bacterial count obtained p = 0.034. Conclusion: In outpatient treatment, the microorganisms are expected in healthy skin, burned skin is evident in lower counts probably associated with epithelial damage.

Acinetobacter baumannii is an important nosocomial pathogen, but its pathogenic characteristics are not well defined. The purpose of this study was to evaluate biofilm production, mannose-resistant hemagglutination, and gelatinase production in A. baumannii strains isolated from various clinical specimens. Eighty six strains of A. baumannii isolated from 86 hospital inpatients were studied for biofilm formation, gelatinase activity, and mannose-resistant hemagglutination. The isolates were identified using conventional techniques and/or the API 2ONE system. Comparisons of biofilm production, gelatinase activity, and mannose-resistant hemagglutination were made by chi-squared analysis. Twenty two and 61 of the isolates agglutinated human group O and AB erythrocytes in the presence of mannose, respectively. Gelatinase activity was detected in 12 isolates (14%), while 64 isolates formed biofilms. Several parameters may play important roles in causing infection in colonized patients. Id...

Climate change is causing rapid changes in reef structure, biodiversity, and function, though most sponges are predicted to tolerate conditions projected for 2100. Sponges maintain intimate relationships with microbial symbionts, with previous studies suggesting that microbial flexibility may be pivotal to success under ocean acidification (OA). We performed a reciprocal transplantation of the coral reef sponges Coelocarteria singaporensis and Stylissa cf. flabelliformis between a control reef site and an adjacent CO2 vent site in Papua New Guinea to explore how the sponge microbiome responds to OA. Microbial communities of C. singaporensis, which differed initially between sites, did not shift towards characteristic control or vent microbiomes, even though relative abundances of Chloroflexi and Cyanobacteria increased and that of Thaumarchaeota decreased 7 months after transplantation to the control site. Microbial communities of S. cf. flabelliformis, which were initially stable b...

Background-Chlorhexidine skin cleansing might substantially reduce neonatal infection and mortality in developing countries. Few data exist on the impact of chlorhexidine cleansing on skin colonization of infants during the first day of life or on the absorption potential of chlorhexidine during newborn skin cleansing. Methods-Hospital born newborns in Kathmandu, Nepal were randomly allocated to full-body skin cleansing with 0.25%, 0.50%, or 1.00% chlorhexidine solution. Skin swabs were collected from the axilla, inguinal and peri-umbilical areas before cleansing (baseline), and at 2 and 24 hours after treatment. Skin flora was quantified and organisms identified. In a sub-sample, heel prick blood was collected 24 hours after the cleansing and percutaneous absorption of chlorhexidine was assessed. Results-Among 286 enrolled newborns, no adverse effects on skin were reported and body temperature was minimally reduced (mean reduction 0.33°C). In all groups, positive skin culture rates were significantly reduced at 2 hours but generally not at 24 hours; greater reductions were observed with higher concentrations of chlorhexidine. Effect at 24 hours was highest in the 1.00% group (37% lower positive skin culture rate). For 15 of 75 infants with heel pricks, chlorhexidine was detected at trace concentrations (< 8 ng/ml, n=14; 25.8 ng/ml, n=1). Conclusions-Chlorhexidine skin cleansing appeared safe and reduced skin flora in newborns in a dose-dependent manner 2 hours after treatment. Greater residual effect at the highest concentration (1%) might provide broader benefit and may simplify combined maternal and neonatal regimens by matching the concentration used for vaginal cleansing during labor.

A randomized double-blind trial with a 7-valent pneumococcal conjugate vaccine was conducted in The Netherlands among 383 children, aged 1 to 7 years, with a history of recurrent acute otitis media. No effect of vaccination on the pneumococcal colonization rate was found. However, a shift in serotype distribution was clearly observed (R. Veenhoven et al., Lancet 361:2189-2195, 2003). We investigated the molecular epidemiology of 921 pneumococcal isolates retrieved from both the pneumococcal vaccine (PV) and control vaccine (CV) groups during the vaccination study. Within individuals a high turnover rate of pneumococcal restriction fragment end labeling genotypes, which was unaffected by vaccination, was observed. Comparison of the genetic structures before and after completion of the vaccination scheme revealed that, despite a shift in serotypes, there was clustering of 70% of the pneumococcal populations. The remaining isolates (30%) were equally observed in the PV and CV groups. I...

Although mucin O-glycosylation of sputum from individuals suffering from cystic fibrosis (CF) is known to be altered relative to their unaffected counterparts, protein N-glycosylation of CF sputum remains structurally and functionally under-characterized. We report the first N-glycome of soluble proteins in sputum derived from five CF patients, two pathogen-free and two pathogen-infected/colonized non-CF individuals suffering from other pulmonary conditions. N-Glycans were profiled using porous graphitized carbon-liquid chromatography-negative ion-tandem mass spectrometry following enzymatic release from sputum proteins. The composition, topology and linkage isomers of 68 N-glycans were characterized and relatively quantified. Recurring structural features in all sputum N-glycomes were terminal α2,6-sialylation, α1,6-core fucosylation, β1,4-bisecting GlcNAcylation and compositions indicating paucimannosylation. Despite covering different genotypes, age, gender and microbial flora, t...

This study was performed to gain better insight into the mechanisms involved in carious destruction of human dentin by Streptococcus mutans. In particular, bacterial colonization of dentin surfaces and bacterial invasion in dentin were studied. Streptococcus mutans (S. mutans), strain NCTC 10449, was grown on sterile dentin blocks in a 10% CO2 atmosphere at 37 degrees C. After 72, 120, 144 and 288 h of incubation the specimens were processed for scanning electron microscopic examination. The colonization of the dentinal surface progressed slowly and was nearly complete after 288 h. Invasion of S. mutans into the dentinal tubules was found occasionally and was limited to the initial 5 micron of the tubular lumen. The acid metabolites produced by S. mutans, caused lesions of the dentinal structures in the close proximity of the bacteria. From the results of this in vitro study it appears that carious destruction of exposed dentinal surfaces by S. mutans mainly occurs at the exposed de...

Bacterial resistance to antibiotics poses enormous health and economic burdens to our society, and it is of the essence to explore old and new ways to deal with these problems. Here we review the current status of multi-resistance genes and how they spread among bacteria. We discuss strategies to deal with resistant bacteria, namely the search for new targets and the use of inhibitors of protein-protein interactions, fragment-based methods, or modified antisense RNAs. Finally, we discuss integrated approaches that consider bacterial populations and their niches, as well as the role of global regulators that activate and/or repress the expression of multiple genes in fluctuating environments and, therefore, enable resistant bacteria to colonize new niches. Understanding how the global regulatory circuits work is, probably, the best way to tackle bacterial resistance.

Background: In May 2015, we noticed an increase in carbapenem-resistant Acinetobacter baumannii (CRAB) infections in the Medical Intensive Care Unit (MICU). To investigate this, we studied the extent of environmental contamination and subsequent onward clonal transmission of CRAB. Methods: We conducted a one-day point prevalence screening (PPS) of the patients and environment in the MICU. We screened patients using endotracheal tube aspirates and swabs from nares, axillae, groin, rectum, wounds, and exit sites of drains. We collected environmental samples from patients' rooms and environment outside the patients' rooms. CRAB isolates from the PPS and clinical samples over the subsequent one month were studied for genetic relatedness by whole genome sequencing (WGS). Results: We collected 34 samples from seven patients and 244 samples from the environment. On the day of PPS, we identified 8 CRAB carriers: 3 who screened positive and 5 previously known clinical infections. We detected environmental contamination in nearly two-thirds of the rooms housing patients with CRAB. WGS demonstrated genetic clustering of isolates within rooms but not across rooms. We analysed 4 CRAB isolates from clinical samples following the PPS. One genetically-related CRAB was identified in the respiratory sample of a patient with nosocomial pneumonia, who was admitted to the MICU five days after the PPS. Conclusion: The extensive environmental colonization of CRAB by patients highlights the importance of environmental hygiene. The transmission dynamics of CRAB needs further investigation.

The genetic diversity among 31 putativeAzotobacterisolates obtained from agricultural and non-agricultural soils was assessed using rep-PCR genomic fingerprinting and identified to species level by ARDRA and partial 16S rRNA gene sequence analysis. High diversity was found among the isolates, identified asA. chroococcum,A. salinestris, andA. armeniacus. Selected isolates were characterized on the basis of phytohormone biosynthesis, nitrogenase activity, siderophore production, and phosphate solubilization. Indole-3 acetic-acid (IAA), gibberellin (GA3) and zeatin (Z) biosynthesis, nitrogenase activity, and siderophore production were found in all evaluated strains, with variation among them, but no phosphate solubilization was detected. Phytohormones excreted to the culture medium ranged in the following concentrations: 2.2–18.2 μg IAA mL−1, 0.3–0.7 μg GA3 mL−1, and 0.5–1.2 μg Z mL−1. Seed inoculations with further selectedAzotobacterstrains and treatments with their cell-free cultur...

We sequenced the first blaVIM-1-positive Klebsiella pneumoniae strain isolated in Singapore. The isolate belongs to multilocus sequence type 2542 (ST2542), and blaVIM-1 was the first gene in an integron that also contained aacA4, aphA15, aadA1, catB2, qacEdelta1, and sul1.

Background. Shunt infections are one of the major causes of mortality and morbidity of patients with hydrocephalus. The aim of this research is to compare the bacterial colonization characteristics of a regular silicone elastomer shunt material coated with polyvinylpyrrolidone and dimethylpolysiloxane (silicone). Method. Regular coated shunt materials were compared by in-vivo and in-vitro methods. In the in-vitro experiment, silicone and coated material immersed and not immersed in vancomycin solution was treated with a certain concentration of Staphylococcus epidermidis. In the in-vivo study, silicone and coated material specimens were treated with Staphylococcus epidermidis and they were stereotactically placed in the lateral ventricles of the rats. One week after the inoculation, shunt pieces were removed and the colonies were counted by using a scanning electron microscope. Findings. There was a statistically significant difference of colonization in the in-vitro groups in coated material vs. silicone, coated material vs. vancomycin treated silicone, vancomycin treated coated material vs. silicone, vancomycin treated coated material vs. vancomycin treated silicone. There was no statistically significant difference for colonization in in-vitro groups of coated material and vancomycin treated coated material. With in-vivo experiments we can say that, coated material catheters are superior than the silicone catheters in respect to colonization but after the bacterial colonization has occurred, the amount of colonization did not differ. Interpretation. Coated material catheters are superior to silicone catheters and they prevent bacterial colonization in some respect.

Background: The human gastrointestinal (GI) tract microbiota has been a subject of intense research throughout the 3rd Millennium. Now that a general picture about microbiota composition in health and disease is emerging, questions about factors determining development of microbiotas with specific community structures will be addressed. To this end, usage of murine models for colonization studies remains crucial. Optical in vivo imaging of either bioluminescent or fluorescent bacteria is the basis for non-invasive detection of intestinal colonization of bacteria. Although recent advances in in vivo fluorescence imaging have overcome many limitations encountered in bioluminescent imaging of intestinal bacteria, such as requirement for live cells, high signal attenuation and 2D imaging, the method is still restricted to bacteria for which molecular cloning tools are available. Results: Here, we present usage of a lipophilic fluorescent dye together with Katushka far-red fluorescent protein to establish a dual-color in vivo imaging system to monitor GI transit of different bacterial strains, suitable also for strains resistant to genetic labeling. Using this system, we were able to distinguish two different E. coli strains simultaneously and show their unique transit patterns. Combined with fluorescence molecular tomography, these distinct strains could be spatially and temporally resolved and quantified in 3D. Conclusions: Developed novel method for labeling microbes and identify their passage both temporally and spatially in vivo makes now possible to monitor all culturable bacterial strains, also those that are resistant to conventional genetic labeling.

Self-protecting Ti6Al4V alloy pins were prepared by covalent bonding of bis(ethylene glycol) linkers, then vancomycin to the oxidized, aminopropylated Ti6Al4V alloy surface. Fluorescence modification-enabled estimation of yields of free amines on the metallic surface monolayer at each reaction step. The vancomycin-protected Ti6Al4V pins were not colonized by Staphylococcus aureus, even after 44 days storage in physiological buffer. These results provide a basis for testing self-protection against S. aureus colonization in animal models.

Civil engineers have a responsibility to take measures to protect marine biodiversity by selecting more bioreceptive construction materials in the design of marine infrastructure, for better biodiversity conservation. In this study, it was shown that pre-carbonation of cementitious materials accelerates their bacterial colorization by lowering the pH of their surface. It has been shown both in the laboratory and in-situ tests that the bacterial colonization of cementitious materials is influenced by the pH and the type of cement. By comparing the bacterial colonization of Portland cement mortars, CEM I, and slag cement, CEM III, mortars, it was found that the CEM III mortars are more bioreceptive than the CEM I mortars. This study presented and verified a novel experimental laboratory approach which can be used to evaluate the bacterial colonization (bioreceptivity) of cementitious materials in marine environment. The approach could be taken up in future recommendations to enable engineers to eco-design more eco-friendly marine infrastructure and develop green-engineering projects.

This study shows the potential risk of microfiltration between two different types of implant-abutment connections screwed at 45 Ncm: external and internal. For the first time the use of a mechanical artificial mouth is used with the values (compression and torsion loads with a frequency of 2 Hz) of the human chewing. The mechanical tests were performed with an artificial saliva at 37 oC. The microgap in the connection was measured by an Image Analysis software incorporated in a high resolution scanning electron microscopy. Implant connections were filled with methylene blue by using self-adjustable precision pipettes and the quantity of leakage was determined by high sensitivity spectometry. We showed that the internal connection has lower microgaps compared to the external ones and these microgaps increased with the number of mechanical cycles. The leakage of methylene blue was higher when the external connection was performed. Microgaps and the influence of the mechanical loads are very important for the long-term behavior avoiding the bacteria colonization in the dental implants. These aspects should be known by the implantologists.

The relevance of large clostridial toxin-negative, binary toxin-producing [A-B-CDT + ] C. difficile strains in human infection is controversial. A-B-CDT + C. difficile strains [FIG 1] are considered clinically irrelevant despite their detection in symptomatic individuals and diarrhoeic animals 1. Recently, we reported the presence of multiple AMR genes in these strains 1. Here we investigate other putative virulence traits that may contribute to their role in idiopathic diarrhoea.

Periprosthetic infection is increasingly prevalent in orthopaedics with infection rates of 2% to 15% after total hip arthroplasty. To effectively decrease bacterial attachment, colonization, and subsequent development of periprosthetic infection, we previously described a method to covalently bond vancomycin to smooth Ti alloy surfaces. To attach vancomycin, the Ti surface is first passivated to create a fresh oxide layer. Previously, passivation has been achieved with an H 2 SO 4 /H 2 O 2 etch that can destroy the topography of the underlying implant. Passivation by hydrothermal aging as well as by H 2 SO 4 / H 2 O 2 incubation produced a robust oxide layer, but only hydrothermal aging left the geometry unaltered. These hydrothermally passivated Kirschner wires and smooth or beaded Ti surfaces were chemically coupled with vancomycin. Antibiotic-coupled samples representing all three geometries were uniformly covered with antibiotic, resisted colonization by Staphylococcus aureus for longer than 8 hours, and retained their biocompatibility as assessed by normal attachment and morphology of preosteocytic MLO-A5 cells. Using this technique, we believe it is possible to passivate many complex implant designs/ geometries as a first step toward covalent bonding of antibiotics or other bioactive factors.

Background Bone grafts are frequently used to supplement bone stock and to establish structural stability. However, graft-associated infection represents a challenging complication leading to increased patient morbidity and healthcare costs. Questions/purposes We therefore designed this study to (1) determine if increasing initial S. aureus inoculation of bone allograft results in a proportionate increase in colonization; (2) assess if antibiotics decrease colonization and if antibiotic tethering to allograft alters its ability to prevent bacterial colonization; and (3) determine if covalent modification alters the allograft topography or its biological properties. Methods Allograft bone and vancomycin-modified bone (VAN-bone) was challenged with different doses of S. aureus for times out to 24 hours in the presence or absence of solution vancomycin. Bacterial colonization was assessed by fluorescence, scanning electron microscopy (SEM), and by direct colony counting. Cell density and distribution of osteoblast-like cells on control and modified allograft were then compared. Results Bacterial attachment was apparent within 6 hours with colonization and biofilm formation increasing with time and dose. Solution vancomycin failed to prevent bacterial attachment whereas VAN-bone successfully resisted colonization. The allograft modification did not affect the attachment and distribution of osteoblast-like cells. Conclusions Allograft bone was readily colonized by S. aureus and covered by a biofilm with especially florid growth in natural topographic niches. Using a novel covalent modification, allograft bone was able to resist colonization by organisms while retaining the ability to allow adhesion of osteoblastic cells. Clinical Relevance Generation of allograft bone that can resist infection in vivo would be important in addressing one of the most challenging problems associated with the use of allograft, namely infection.

BACKGROUND AND OBJECTIVES: In developed countries, where omphalitis has become rare and related mortality nil, benefits of antiseptic use in umbilical cord care have not been demonstrated. We aimed to assess the noninferiority of dry care compared with antiseptics in France where antiseptic use is widespread. METHODS: We conducted a noninferiority, cluster-randomized, 2-period crossover trial, in 6 French university maternity units including all infants born after 36 weeks’ gestation. Maternity units were randomly assigned to provide either their usual antiseptic care or a dry care umbilical cord method for a 4-month period, and then units switched to the alternate cord cleansing method for a 4-month period. The primary outcome was neonatal omphalitis, adjudicated by an independent blinded committee based on all available photographs, clinical, and bacteriological data. We used a noninferiority margin of 0.4%. Analysis was performed per protocol and by intention to treat. RESULTS: A...

In May 2015, we noticed an increase in carbapenem-resistant (CRAB) infections in the Medical Intensive Care Unit (MICU). To investigate this, we studied the extent of environmental contamination and subsequent onward clonal transmission of CRAB. We conducted a one-day point prevalence screening (PPS) of the patients and environment in the MICU. We screened patients using endotracheal tube aspirates and swabs from nares, axillae, groin, rectum, wounds, and exit sites of drains. We collected environmental samples from patients&#39; rooms and environment outside the patients&#39; rooms. CRAB isolates from the PPS and clinical samples over the subsequent one month were studied for genetic relatedness by whole genome sequencing (WGS). We collected 34 samples from seven patients and 244 samples from the environment. On the day of PPS, we identified 8 CRAB carriers: 3 who screened positive and 5 previously known clinical infections. We detected environmental contamination in nearly two-thi...

Acinetobacter baumannii is an important nosocomial pathogen, but its pathogenic characteristics are not well defined. The purpose of this study was to evaluate biofilm production, mannose-resistant hemagglutination, and gelatinase production in A. baumannii strains isolated from various clinical specimens. Eighty six strains of A. baumannii isolated from 86 hospital inpatients were studied for biofilm formation, gelatinase activity, and mannose-resistant hemagglutination. The isolates were identified using conventional techniques and/or the API 2ONE system. Comparisons of biofilm production, gelatinase activity, and mannose-resistant hemagglutination were made by chi-squared analysis. Twenty two and 61 of the isolates agglutinated human group O and AB erythrocytes in the presence of mannose, respectively. Gelatinase activity was detected in 12 isolates (14%), while 64 isolates formed biofilms. Several parameters may play important roles in causing infection in colonized patients. Id...

Helicobacter pylori (H. Pylori) has been associated with the development of gastritis, peptic ulcer and gastric cancer. Although H. pylori infects up to more than half of the world's population, to date the precise modes of transmission has not been fully understood yet. Therefore a study was planned to investigate whether the tonsils and the adenoid tissue were the reservoir or the gate for the entrance of H. pylori. Methods: The adenotonsillectomy specimens obtained from 50 children, between two and 10 years of age were examined for H. Pylori colonization by the CLO-test method. Before tonsillectomy, anti-H. pylori IgG antibody titers were detected by commercial enzyme immunoassay method in venous blood and H. pylori antigen enzyme immunoassay for detection of H. pylori in stool was used to define current infection status. Results: The stool antigen was positive in 25 (50%) of 50 children. Serum IgG antibody was positive in 28 (56%) patients and both tests were positive in 21 (42%) patients. H. pylori positivity was not detected in any one of the adenotonsillectomy specimens with the CLO-test method. Conclusion: In this study although H. pylori was detected in stools of children, it was not detected in adenotonsillectomy specimens with CLO-test method. The results may indicate that H. pylori does not colonize in either adenoid or tonsils and that these tissues do not constitute a reservoir for H. pylori infection.

The nasopharynx (NP) is a reservoir for microbes associated with acute respiratory infections (ARIs). Lung inflammation resulting from ARIs during infancy is linked to asthma development. We examined the NP microbiome during the critical first year of life in a prospective cohort of 234 children, capturing both the viral and bacterial communities and documenting all incidents of ARIs. Most infants were initially colonized with Staphylococcus or Corynebacterium before stable colonization with Alloiococcus or Moraxella. Transient incursions of Streptococcus, Moraxella, or Haemophilus marked virus-associated ARIs. Our data identify the NP microbiome as a determinant for infection spread to the lower airways, severity of accompanying inflammatory symptoms, and risk for future asthma development. Early asymptomatic colonization with Streptococcus was a strong asthma predictor, and antibiotic usage disrupted asymptomatic colonization patterns. In the absence of effective anti-viral therap...

Chronic rhinosinusitis (CRS) is an inflammatory disease of the nasal and paranasal mucosa (1), which has been increasing in prevalence and incidence worldwide and affects between 4% and 28% of the population in the western countries (2, 3). Pathophysiological studies have indicated that CRS can be classified into two subgroups based on the absence (CRSsNP) or presence (CRSwNP) of nasal polyps, which have distinctive inflammatory cell and mediator profiles (4-7) and specific features of remodelling (8, 9). Earlier

Aim: To compare the health of the soft tissues towards zirconia and titanium abutments in man, as observed using histological data. Material and Methods: Twenty patients received two mandibular implants with either a zirconia or titanium abutment (split mouth study design, left-right randomization). After 3 months soft tissue biopsies were prepared for histological evaluation. They were subjected to blind evaluation. The number of blood vessels per surface unit and an inflammation grading scale score ranging from 1 to 4 were determined. Results: Paired samples from 17 patients were suitable for analysis, 3 with unsevered implant-abutment connections and 14 solely containing soft tissue. All showed a well-keratinized stratified squamous epithelium which was continuous with the barrier (junctional) epithelium that faced the abutment surface. The normal epithelial build-up could be recognized with little signs of inflammation. No statistically significant difference in tissues adjacent to zirconia and titanium abutment surfaces were seen with respect to vascular density (20.5 SD 4.4 and 20.7 SD 3.2) or inflammation grading scale scores (3.2 SD 0.7 versus 3.1 SD 0.7). Conclusion: No differences in soft tissue health were seen in peri-implant mucosa adjacent to zirconia and titanium abutment surfaces.

A randomized double-blind trial with a 7-valent pneumococcal conjugate vaccine was conducted in The Netherlands among 383 children, aged 1 to 7 years, with a history of recurrent acute otitis media. No effect of vaccination on the pneumococcal colonization rate was found. However, a shift in serotype distribution was clearly observed (R. Veenhoven et al., Lancet 361:2189-2195, 2003). We investigated the molecular epidemiology of 921 pneumococcal isolates retrieved from both the pneumococcal vaccine (PV) and control vaccine (CV) groups during the vaccination study. Within individuals a high turnover rate of pneumococcal restriction fragment end labeling genotypes, which was unaffected by vaccination, was observed. Comparison of the genetic structures before and after completion of the vaccination scheme revealed that, despite a shift in serotypes, there was clustering of 70% of the pneumococcal populations. The remaining isolates (30%) were equally observed in the PV and CV groups. I...

Background: The human gastrointestinal (GI) tract microbiota has been a subject of intense research throughout the 3rd Millennium. Now that a general picture about microbiota composition in health and disease is emerging, questions about factors determining development of microbiotas with specific community structures will be addressed. To this end, usage of murine models for colonization studies remains crucial. Optical in vivo imaging of either bioluminescent or fluorescent bacteria is the basis for non-invasive detection of intestinal colonization of bacteria. Although recent advances in in vivo fluorescence imaging have overcome many limitations encountered in bioluminescent imaging of intestinal bacteria, such as requirement for live cells, high signal attenuation and 2D imaging, the method is still restricted to bacteria for which molecular cloning tools are available. Results: Here, we present usage of a lipophilic fluorescent dye together with Katushka far-red fluorescent protein to establish a dual-color in vivo imaging system to monitor GI transit of different bacterial strains, suitable also for strains resistant to genetic labeling. Using this system, we were able to distinguish two different E. coli strains simultaneously and show their unique transit patterns. Combined with fluorescence molecular tomography, these distinct strains could be spatially and temporally resolved and quantified in 3D. Conclusions: Developed novel method for labeling microbes and identify their passage both temporally and spatially in vivo makes now possible to monitor all culturable bacterial strains, also those that are resistant to conventional genetic labeling.

Helicobacter pylori (H. Pylori) has been associated with the development of gastritis, peptic ulcer and gastric cancer. Although H. pylori infects up to more than half of the world's population, to date the precise modes of transmission has not been fully understood yet. Therefore a study was planned to investigate whether the tonsils and the adenoid tissue were the reservoir or the gate for the entrance of H. pylori. Methods: The adenotonsillectomy specimens obtained from 50 children, between two and 10 years of age were examined for H. Pylori colonization by the CLO-test method. Before tonsillectomy, anti-H. pylori IgG antibody titers were detected by commercial enzyme immunoassay method in venous blood and H. pylori antigen enzyme immunoassay for detection of H. pylori in stool was used to define current infection status. Results: The stool antigen was positive in 25 (50%) of 50 children. Serum IgG antibody was positive in 28 (56%) patients and both tests were positive in 21 (42%) patients. H. pylori positivity was not detected in any one of the adenotonsillectomy specimens with the CLO-test method. Conclusion: In this study although H. pylori was detected in stools of children, it was not detected in adenotonsillectomy specimens with CLO-test method. The results may indicate that H. pylori does not colonize in either adenoid or tonsils and that these tissues do not constitute a reservoir for H. pylori infection.

Introduction: Crohn's disease (CD) and ulcerative colitis (UC) are the two major forms of inflammatory bowel disease (IBD). A high prevalence of Campylobacter concisus was previously detected in paediatric CD and adult UC. Currently, the prevalence of C. concisus in adult CD and the preferential colonization sites of Campylobacter species in the human intestine are unknown. In this study, we examined the prevalence of Campylobacter species in biopsies collected from multiple anatomic sites of adult patients with IBD and controls. Methods: Three hundred and one biopsies collected from ileum, caecum, descending colon and rectum of 28 patients IBD (15 CD and 13 UC) and 33 controls were studied. Biopsies were used for DNA extraction and detection of Campylobacter species by PCR-sequencing and Campylobacter cultivation. Results: A significantly higher prevalence of C. concisus in colonic biopsies of patients with CD (53%) was detected as compared with the controls (18%). Campylobacter genus-PCR positivity and C. concisus positivity in patients with UC were 85% and 77% respectively, being significantly higher than that in the controls (48% and 36%). C. concisus was more often detected in descending colonic and rectal biopsies from patients with IBD in comparison to the controls. C. concisus was isolated from patients with IBD. Conclusion: The high intestinal prevalence of C. concisus in patients with IBD, particularly in the proximal large intestine, suggests that future studies are needed to investigate the possible involvement of C. concisus in a subgroup of human IBD. To our knowledge, this is the first report of the association between adult CD and C. concisus as well as the first study of the preferential colonization sites of C. concisus in the human intestine.

Citric acid (CA) has been suggested as an effective antimicrobial agent against biofilms formed on titanium. However, the antimicrobial effect of CA in biofilms formed in the oral environment and its effects on the physical properties of titanium surface remain unknown. Therefore, this study evaluated the antimicrobial effect of CA on in situ biofilm, whether this treatment favors the bacteria re-colonization and investigated its effect on the electrochemical properties of titanium. In the in situ test, volunteers wore a palatal appliance containing titanium discs. After 7 days, the discs (N = 21) were exposed in vitro to the following treatments: immersion in 0.9% sodium chloride (control); 40% CA immersion; and 40% CA rubbing. Afterwards, these discs (N = 18) were exposed in vitro to new bacterial adhesion with Streptococcus sanguinis. New discs (N = 18) without biofilm were exposed to the treatments and subjected to electrochemical tests and surface characterization. Data were an...

This study was conducted to evaluate the impact of central venous catheters impregnated with chlorhexidine and silver sulphadiazine on the incidence of colonization and catheter-related bloodstream infection in critically ill patients. One hundred and thirty-three patients requiring central venous catheterization were chosen at random to receive either an antiseptic-impregnated triple-lumen catheter (NZ64) or a standard triplelumen catheter (NZ69). The mean (SD) durations of catheterization for the antiseptic and standard catheters were 11.7 (5.8) days (median 10; range 3-29) and 8.9 (4.6) days (median 8.0; range 3-20), respectively (PZ0.006). Fourteen (21.9%) of the antiseptic catheters and 14 (20.3%) of the standard catheters had been colonized at the time of removal (PZ0.834). Four cases (6.3%) of catheter-related bloodstream infection were associated with antiseptic catheters and one case (1.4%) was associated with a standard catheter (PZ0.195). The catheter colonization rates were 18.7/1000 catheter-days for the antiseptic catheter group and 22.6/1000 catheterdays for the standard catheter group (PZ0.640). The catheter-related bloodstream infection rates were 5.3/1000 catheter-days for the antiseptic catheter group and 1.6/1000 catheter-days for the standard catheter group (PZ0.452). In conclusion, our results indicate that the use of antiseptic

As a competitive exclusion agent, Lactobacillus johnsonii FI9785 has been shown to prevent the colonization of selected pathogenic bacteria from the chicken gastrointestinal tract. During growth of the bacterium a rare but consistent emergence of an altered phenotype was noted, generating smooth colonies in contrast to the wild type rough form. A smooth colony variant was isolated and two-dimensional gel analysis of both strains revealed a protein spot with different migration properties in the two phenotypes. The spot in both gels was identified as a putative tyrosine kinase (EpsC), associated with a predicted exopolysaccharide gene cluster. Sequencing of the epsC gene from the smooth mutant revealed a single substitution (G to A) in the coding strand, resulting in the amino acid change D88N in the corresponding gene product. A native plasmid of L. johnsonii was engineered to produce a novel vector for constitutive expression and this was used to demonstrate that expression of the wild type epsC gene in the smooth mutant produced a reversion to the rough colony phenotype. Both the mutant and epsC complemented strains had increased levels of exopolysaccharides compared to the wild type strain, indicating that the rough phenotype is not solely associated with the quantity of exopolysaccharide. Another gene in the cluster, epsE, that encoded a putative undecaprenyl-phosphate galactosephosphotransferase, was deleted in order to investigate its role in exopolysaccharide biosynthesis. The DepsE strain exhibited a large increase in cell aggregation and a reduction in exopolysaccharide content, while plasmid complementation of epsE restored the wild type phenotype. Flow cytometry showed that the wild type and derivative strains exhibited clear differences in their adhesive ability to HT29 monolayers in tissue culture, demonstrating an impact of EPS on surface properties and bacteria-host interactions.

Introduction: Crohn's disease (CD) and ulcerative colitis (UC) are the two major forms of inflammatory bowel disease (IBD). A high prevalence of Campylobacter concisus was previously detected in paediatric CD and adult UC. Currently, the prevalence of C. concisus in adult CD and the preferential colonization sites of Campylobacter species in the human intestine are unknown. In this study, we examined the prevalence of Campylobacter species in biopsies collected from multiple anatomic sites of adult patients with IBD and controls. Methods: Three hundred and one biopsies collected from ileum, caecum, descending colon and rectum of 28 patients IBD (15 CD and 13 UC) and 33 controls were studied. Biopsies were used for DNA extraction and detection of Campylobacter species by PCR-sequencing and Campylobacter cultivation. Results: A significantly higher prevalence of C. concisus in colonic biopsies of patients with CD (53%) was detected as compared with the controls (18%). Campylobacter genus-PCR positivity and C. concisus positivity in patients with UC were 85% and 77% respectively, being significantly higher than that in the controls (48% and 36%). C. concisus was more often detected in descending colonic and rectal biopsies from patients with IBD in comparison to the controls. C. concisus was isolated from patients with IBD. Conclusion: The high intestinal prevalence of C. concisus in patients with IBD, particularly in the proximal large intestine, suggests that future studies are needed to investigate the possible involvement of C. concisus in a subgroup of human IBD. To our knowledge, this is the first report of the association between adult CD and C. concisus as well as the first study of the preferential colonization sites of C. concisus in the human intestine.

Self-protecting Ti6Al4V alloy pins were prepared by covalent bonding of bis(ethylene glycol) linkers, then vancomycin to the oxidized, aminopropylated Ti6Al4V alloy surface. Fluorescence modification-enabled estimation of yields of free amines on the metallic surface monolayer at each reaction step. The vancomycin-protected Ti6Al4V pins were not colonized by Staphylococcus aureus, even after 44 days storage in physiological buffer. These results provide a basis for testing self-protection against S. aureus colonization in animal models.

The colonization of orthopyroxene crystals by a pleomorphic bacterium and the mineralogical products resulting from a prolonged interaction have been studied. We used Ramlibacter tataouinensis (strain TTB310), which is an aerobic β-Proteobacterium moving over surfaces by gliding motility and whose life cycle includes rods and spherical cysts. Analysis of cultures grown on solid media with micrometer-sized pyroxene and quartz crystals scattered over the surface revealed a taxis of the bacteria toward the crystals. Given the mineralogical non-specificity of the interaction, a mechanism of elasticotaxis is inferred. After the rods had adhered to the pyroxene surface, they differentiated into cysts leading to the formation of microcolonies that were centered on a crystal grain. This suggests an original coupling between the life cycle of R. tataouinensis and the interaction with the crystals. The alteration of orthopyroxene was studied by high-resolution transmission electron microscopy at the interface between cysts and pyroxene crystals. The pyroxene surface showed an amorphous layer that was more developed than that of abiotic control samples processed under the same conditions. Moreover, chemical analyses showed that the dissolution of pyroxene was reduced in the presence of R. tataouinensis. The origin and the significance of the amorphous layers is discussed.

Methicillin-resistant Staphylococcus aureus (MRSA) colonization in anterior nares of diabetic patients may cause morbidity and mortality. Study the epidemiology and risk factor of MRSA colonization may lead to better management of diabetic patients. Swabs were taken from anterior nares of 494 diabetic patients. Demographic characteristics and risk factors entered checklists. Antibiotic susceptibility of Staphylococcus aureus (S. aureus) was determined by disk diffusion method..From these 494 patients, 210 (42.5%) had positive nasal colonization of S. aureus. from 210 positive nasal colonization, 122 (57%) were MRSA (24.7% off all DM patients). The resistance rate of erythromycin, ciprofloxacin, clarithromycin was 81.9, 71.3 and 65.5%. Vancomycin resistance rate was 1.6 %. Our results showed the high prevalence of MRSA infection in diabetic patients. High antibiotic resistance of MRSA isolates may be a future challenge especially when we consider observing vancomycin resistance.