Infection dynamics of vancomycin and inducible clindamycin resistant Enterococcus faecalis in an Indian teaching hospital

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Debasmita Dubey

2015-06-01

Full Text Available Objective: To do surveillance for vancomycin and inducible clindamycin resistance of Enterococcus faecalis (E. faecalis, a Gram-positive bacterium in a teaching hospital. Methods: E. faecalis strains isolated from clinical samples were screened for vancomycin and inducible clindamycin resistance, i.e., D-test positivity, using vancomycin screen agar and blood agar plates, respectively. For the D-test screening, erythromycin resistant (Er-r and clindamycin sensitive (Cd-s strain were used. Results: Of 265 isolated E. faecalis strains, 159 (60% were vancomycin resistant Enterococcus (VRE and 106 were vancomycin sensitive Enterococcus (VSE. Of 265 strains, 42 were constitutively resistant to clindamycin and erythromycin and of 148 Er-r and Cd-s strains, 87 (32.83% had D-test positivity, while the rest 61 strains were D-test negatives. D-test results examined with 6 hospital factors as bivalents, only 2 factors, the VSE/VRE and the presence/absence of prior antibiotic use > 90 days bivalent were statistically significant. A VRE strain with D-test positivity would be picked up 0.570 2 times more frequently than a strain with VSE and D-test positivity. Also, patients with prior antibiotic use > 90 days had 3.737 5 times more chance of picking up D-test positive strains than patients without any prior antibiotic use. Resistance pattern of E. faecalis strains to individual 14 antibiotics were recorded; the maximum values of resistance were against ampicillin 10 μg/disc and linezolid 30 μg/disc. Student’s t-test for hospital acquired and community acquired data revealed that drug resistant strains were equally prevalent in both sources. Conclusions: Prevalence of 60% VRE in both hospital and adjoining community creates consternation. In total 87 (32.83% strains had D-test positivity; patients who had used antibiotics within the last 90 days have got an ample chance of picking of D-test positive E. faecalis. D-test protocol should be followed with

Elimination of Routine Contact Precautions for Endemic Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococcus: A Retrospective Quasi-Experimental Study.

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Martin, Elise M; Russell, Dana; Rubin, Zachary; Humphries, Romney; Grogan, Tristan R; Elashoff, David; Uslan, Daniel Z

2016-11-01

OBJECTIVE To evaluate the impact of discontinuation of contact precautions (CP) for methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) and expansion of chlorhexidine gluconate (CHG) use on the health system. DESIGN Retrospective, nonrandomized, observational, quasi-experimental study. SETTING Two California hospitals. PARTICIPANTS Inpatients. METHODS We compared hospital-wide laboratory-identified clinical culture rates (as a marker of healthcare-associated infections) 1 year before and after routine CP for endemic MRSA and VRE were discontinued and CHG bathing was expanded to all units. Culture data from patients and cost data on material utilization were collected. Nursing time spent donning personal protective equipment was assessed and quantified using time-driven activity-based costing. RESULTS Average positive culture rates before and after discontinuing CP were 0.40 and 0.32 cultures/100 admissions for MRSA (P=.09), and 0.48 and 0.40 cultures/100 admissions for VRE (P=.14). When combining isolation gown and CHG costs, the health system saved $643,776 in 1 year. Before the change, 28.5% intensive care unit and 19% medicine/surgery beds were on CP for MRSA/VRE. On the basis of average room entries and donning time, estimated nursing time spent donning personal protective equipment for MRSA/VRE before the change was 45,277 hours/year (estimated cost, $4.6 million). CONCLUSION Discontinuing routine CP for endemic MRSA and VRE did not result in increased rates of MRSA or VRE after 1 year. With cost savings on materials, decreased healthcare worker time, and no concomitant increase in possible infections, elimination of routine CP may add substantial value to inpatient care delivery. Infect Control Hosp Epidemiol 2016;1-8.

Comparison of in vitro efficacy of linezolid and vancomycin by determining their minimum inhibitory concentrations against methicillin resistant Staphylococcus aureus (MRSA)

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Kaleem, F.; Usman, J.; Hassan, A.

2011-01-01

Objectives: To compare the in vitro activities of vancomycin and linezolid against methicillin resistant Staphyloccus aureus in our set up to help in formulating a better empirical treatment and reduce the emergence of vancomycin resistant Staphylococcus aureus. Methods: The study was conducted over a period of 6 months(July 1, 2009 - Dec 1, 2009). Fifty Methicillin resistant Staphylococcus aureus isolated from the clinical isolates of Military Hospital Rawalpindi were subjected to the determination of Minimum inhibitory concentrations of linezolid and vancomycin using E-strips. Results: All the isolated organisms were uniformly susceptible to both the antibiotics. Vancomycin showed higher minimum inhibitory concentrations (MICs) as compared to linezolid MICs. Conclusion: This study suggests that linezolid and vancomycin have similar in vitro efficacy for methicillin resistant Staphyloccus aureus infections. (author)

Reduced susceptibility to vancomycin and biofilm formation in methicillin-resistant Staphylococcus epidermidis isolated from blood cultures

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Luiza Pinheiro

2014-11-01

Full Text Available This study aimed to correlate the presence of ica genes, biofilm formation and antimicrobial resistance in 107 strains of Staphylococcus epidermidis isolated from blood cultures. The isolates were analysed to determine their methicillin resistance, staphylococcal cassette chromosome mec (SCCmec type, ica genes and biofilm formation and the vancomycin minimum inhibitory concentration (MIC was measured for isolates and subpopulations growing on vancomycin screen agar. The mecA gene was detected in 81.3% of the S. epidermidis isolated and 48.2% carried SCCmec type III. The complete icaADBC operon was observed in 38.3% of the isolates; of these, 58.5% produced a biofilm. Furthermore, 47.7% of the isolates grew on vancomycin screen agar, with an increase in the MIC in 75.9% of the isolates. Determination of the MIC of subpopulations revealed that 64.7% had an MIC ≥ 4 μg mL-1, including 15.7% with an MIC of 8 μg mL-1 and 2% with an MIC of 16 μg mL-1. The presence of the icaADBC operon, biofilm production and reduced susceptibility to vancomycin were associated with methicillin resistance. This study reveals a high level of methicillin resistance, biofilm formation and reduced susceptibility to vancomycin in subpopulations of S. epidermidis. These findings may explain the selection of multidrug-resistant isolates in hospital settings and the consequent failure of antimicrobial treatment.

Prevalence of Methicillin and Vancomycin resistant Staphylococcus aureus colonization in nasopharynx; Amir-Alam hospital, 2005

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Hasibi M

2007-07-01

Full Text Available Background: Staphylococcus aureus is one of the most common causes of nosocomial infections with high morbidity and mortality rate. Traditionally, methicillin resistant staphylococcus aureus has been considered a major nosocomial pathogen in healthcare facilities, but in the past decade, it has been observed emerging in the community as well. Informations regarding hospital microbial colonization could be an important step for prevention of nosocomial infections. Our objective was clarifying the prevalence of methicillin resistant and vancomycin resistant staphylococcus aureus colonization in nasopharynx. Methods: A descriptive cross sectional study was carried on 106 patients and nursing staff of surgery and hemodialysis wards in Amir-Alam hospital from April 2005 to July 2005. The samples were collected from nasal region of cases using cotton swab by two experienced technician and were sent to laboratory for culture and antibiogram. Results: Twenty six (29.5% out of 106 cases were nasopharyngeal carriers of staphylococcus aureus. Eight cases (7.5% had methicillin resistant staphylococcus aureus. The most frequent colonization rate was seen in hemodialysis nursing staff and in all of them methicillin resistant staphylococcus aureus was reported. Carrier rates in hemodialysis patients were twice compared to surgery ward patients. The interesting point was that no sample of vancomycin resistant staphylococcus aureus was isolated. Conclusion: Prevalence of methicillin resistant staphylococcus aureus colonization seems to be increased; therefore proper management for controlling this problem is mandatory. The results of the present study suggest that the prevalence of methicillin resistant staphylococcus aureus infections is higher than was expected in Iran and vigorous preventive strategies should therefore be taken to stop the growth of this major health problem.

Delayed-Onset Post-Keratoplasty Endophthalmitis Caused by Vancomycin-Resistant Enterococcus faecium

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Julio C. Hernandez-Camarena

2012-10-01

Full Text Available Background: Vancomycin-resistant Enterococcus (VRE endophthalmitis after penetrating keratoplasty (PKP is very rare, the management is a challenge due to both the pattern of antibiotic resistance and the aggressive nature of the infectious process. We report the first delayed-onset case of VRE endophthalmitis after PKP. Materials and Methods: Case report of a 51-year-old female with a 7-week history of PKP who arrived at the emergency room with signs and symptoms of endophthalmitis. Initial visual acuity was light perception, and a posterior pole exam was not possible due to the intense vitreous reaction. Mode B ultrasound was used to assess the posterior pole. The patient underwent pars plana vitrectomy and received intravitreous antibiotics. Results: Vitreous stains and cultures were positive for Enterococcus faecium resistant to vancomycin. Donor rim cultures and viral PCR were negative. Treatment was carried out by repeated intravitreal antibiotics and systemic linezolid. Clinical improvement was seen after the second dose of intravitreous antibiotics and systemic linezolid, but visual acuity remained at light perception consistent with the ischemic changes observed in the posterior pole. Conclusion: VRE endophthalmitis might be associated with positive donor rim cultures. Prompt use of systemic linezolid in addition to intravitreous antibiotics is recommendable, but even with prompt treatment, visual prognosis is guarded.

Clinical Outcome with Oral Linezolid and Rifampin Following Recurrent Methicillin-Resistant Staphylococcus aureus Bacteremia Despite Prolonged Vancomycin Treatment

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Jon-David Schwalm

2004-01-01

Full Text Available Drug-resistant Gram-positive bacteria, especially Staphylococcus aureus, are emerging as the predominant organisms involved in both nosocomial and community-acquired infections. Since the 1980s, vancomycin has been the first-line antibiotic used to treat methicillin-resistant S aureus. However, allergy and intolerance to vancomycin, the increasing number of vancomycin clinical failures and the existence of vancomycin intermediate-susceptible isolates of S aureus suggest that new antibiotics are needed. This paper reports the only known case of a successful clinical outcome with long term oral linezolid and rifampin therapy in the management of recurrent and persistent methicillin-resistant S aureus bacteremia with metastatic infections despite prolonged vancomycin use. More than two years since the initiation of linezolid and rifampin, the study patient has been clinically well with no evidence of adverse drug reactions including cytopenia and hepatic toxicities. Physicians must be aware of the novel developments in antibiotic therapy to treat drug-resistant bacterial infections.

Characterization of vancomycin-resistant and vancomycin-susceptible Enterococcus faecium isolates from humans, chickens and pigs by RiboPrinting and pulsed-field gel electrophoresis

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Hammerum, Anette Marie; Fussing, Vivian; Aarestrup, Frank Møller

2000-01-01

Forty-eight vancomycin-resistant and 35 vancomycin-sensitive Danish Enterococcus faecium isolates obtained from pigs, chickens and humans, as well as the human vanA reference isolate BM4147, were characterized by EcoRI RiboPrinting and Smal pulsed-field gel electrophoresis. RiboPrinting of the 84...

Simple test of synergy between ampicillin and vancomycin for resistant strains of Enterococcus faecium.

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Green, M; Barbadora, K; Wadowsky, R M

1994-11-01

The combination of ampicillin and vancomycin kills some but not all strains of ampicillin- and vancomycin-resistant Enterococcus faecium. We compared a simple test for synergy utilizing a commercially available microdilution susceptibility system with time-kill studies and determined acceptable breakpoints for this test for 20 strains of ampicillin- and vancomycin-resistant E. faecium. The combination of ampicillin and vancomycin was tested for synergy by time-kill, broth macrodilution, and broth microdilution procedures. Repeat testing of isolates by macro- and microdilution synergy methods yielded MICs that were within one twofold dilution of each other for both intra- and intertest comparisons. Synergy was always detected by time-kill studies when the MIC of ampicillin in the combination synergy screen was 16 micrograms/ml in the combination microdilution synergy screen. The determination of the synergy by the broth microdilution procedure appears to be simple, convenient, and accurate.

Prevalence of methicillin-resistant staphylococci isolated from different biological samples at Policlinico Umberto I of Rome: correlation with vancomycin susceptibility

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Maria Teresa Mascellino

2011-03-01

Full Text Available The methicillin-resistance is increasing all over the world in the last decade. It is more frequent among coagulase-negative staphylococci (MRCoNS; infact the 52% of S. epidermidis strains results to be resistant to methicillin.The methicillin-resistant strains also show a reduced sensitivity towards the first-line agents such as glycopeptides and other antibiotics commonly used in therapy such as trimethoprim-sulphamethoxazole, imipenem, gentamycin, fosfomycin and chlarytromicin. Unlike MRSA (Methicillin-resistant S. aureus, MRCoNS resistance to glycopeptides generally concerns teicoplanin. Although vancomycin resistance is rare in Staphylococcus isolates, the detected shift towards higher values of MICs might affect patient’s clinical outcome.

Vancomycin Resistance in Staphylococcus aureus


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McGuinness, Will A.; Malachowa, Natalia; DeLeo, Frank R.

2017-01-01

The evolution of Staphylococcus aureus during the modern antibiotic era has been delineated by distinct strain emergence events, many of which include acquisition of antibiotic resistance. The relative high burden of methicillin-resistant S. aureus (MRSA) in healthcare and community settings is a major concern worldwide. Vancomycin, a glycopeptide antibiotic that inhibits cell wall biosynthesis, remains a drug of choice for treatment of severe MRSA infections. S. aureus strains exhibiting increased resistance to vancomycin, known as vancomycin intermediate-resistant S. aureus (VISA) (MIC = 4-8 µg/mL), were discovered in the 1990s. The molecular basis of resistance in VISA is polygenic and involves stepwise mutations in genes encoding molecules predominantly involved in cell envelope biosynthesis. S. aureus isolates with complete resistance to vancomycin (MIC ≥ 16 µg/mL) are termed vancomycin-resistant S. aureus (VRSA)—they were first reported in the U.S. in 2002. Resistance in VRSA is conferred by the vanA gene and operon, which is present on a plasmid. Although treatment of VRSA infections is challenging, the total number of human VRSA infections to date is limited (14 in the U.S.). By comparison, the burden of VISA is relatively high and the molecular mechanisms of resistance are less well-defined. VISA are associated with persistent infections, vancomycin treatment failure, and poor clinical outcomes. Here, we review in brief progress made toward understanding the acquisition of antibiotic resistance in S. aureus, with an emphasis on the molecular mechanisms underlying vancomycin resistance. PMID:28656013

Presence of the resistance genes vanC1 and pbp5 in phenotypically vancomycin and ampicillin susceptible Enterococcus faecalis.

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Schwaiger, Karin; Bauer, Johann; Hörmansdorfer, Stefan; Mölle, Gabriele; Preikschat, Petra; Kämpf, Peter; Bauer-Unkauf, Ilse; Bischoff, Meike; Hölzel, Christina

2012-08-01

Ampicillin and vancomycin are important antibiotics for the therapy of Enterococcus faecalis infections. The ampicillin resistance gene pbp5 is intrinsic in Enterococcus faecium. The vanC1 gene confers resistance to vancomycin and serves as a species marker for Enterococcus gallinarum. Both genes are chromosomally located. Resistance to ampicillin and vancomycin was determined in 484 E. faecalis of human and porcine origin by microdilution. Since E. faecalis are highly skilled to acquire resistance genes, all strains were investigated for the presence of pbp5 (and, in positive strains, for the penicillin-binding protein synthesis repressor gene psr) and vanC1 (and, in positive strains, for vanXYc and vanT) by using polymerase chain reaction (PCR). One porcine and one human isolate were phenotypically resistant to ampicillin; no strain was vancomycin resistant. Four E. faecalis (3/1 of porcine/human origin) carried pbp5 (MIC=1 mg/L), and four porcine strains were vanC1 positive (minimum inhibitory concentration [MIC]=1 mg/L). Real-time reverse transcriptase (RT)-PCR revealed that the genes were not expressed. The psr gene was absent in the four pbp5-positive strains; the vanXYc gene was absent in the four vanC1-positive strains. However, vanT of the vanC gene cluster was detected in two vanC1-positive strains. To our knowledge, this is the first report on the presence of pbp5, identical with the "E. faecium pbp5 gene," and of vanC1/vanT in E. faecalis. Even if resistance is not expressed in these strains, this study shows that E. faecalis have a strong ability to acquire resistance genes-and potentially to spread them to other bacteria. Therefore, close monitoring of this species should be continued.

Identification and molecular characterization of Van A-type vancomycin-resistant Enterococcus faecalis in Northeast of Brazil

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Marinalda Anselmo Vilela

2006-11-01

Full Text Available The isolation of vancomycin resistant enterococci (VRE in Brazil has rapidly increased, following the world wide tendency. We report in the present study the first isolation of vancomycin resistant Enterococcus faecalis (VRE in the Northeast of Brazil. The four VRE isolates were characterized for antimicrobial susceptibility, genotypic typing by macro restriction of chromosomal DNA followed by pulsed-field gel electrophoresis and for characterization of the Tn1546-like element and plasmid contents. The isolates showed resistance to multiple antibiotics and a single genotype profile, suggesting the dissemination of a single clone among the patients. Tn1546 associated to genetic elements as plasmids shows the importance of infection control measures to avoid the spreading of glycopetide resistance by conjugative transfer of VanA elements.

Is the mazEF toxin-antitoxin system responsible for vancomycin resistance in clinical isolates of Enterococcus faecalis?

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Sadeghifard, Nourkhoda; Soheili, Sara; Sekawi, Zamberi; Ghafourian, Sobhan

2014-01-01

The current study was conducted to investigate the relationship between vancomycin-resistant Enterococcus faecalis (VRE) and the presence of mazEF toxin-antitoxin (TA) system, which may be useful as target for novel antimicrobial therapy concepts. The susceptibility of E. faecalis was determined by MIC, and the presence of the mazEF TA system was evaluated by PCR. Among 200 E. faecalis isolates 39.5% showed resistance to vancomycin (VRE), while 60.5% were susceptible strains (VSE). The mazEF TA system was positive in all VRE isolates (100%), but less prevalent (38/121, 31.4%) among the 121 VSE strains. In conclusion, our study demonstrated a positive relationship between the presence of vancomycin resistance and mazEF TA system. This observation may introduce therapeutic options against a novel antimicrobial target in enterococci.

TOC-39, a novel parenteral broad-spectrum cephalosporin with excellent activity against methicillin-resistant Staphylococcus aureus.

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Hanaki, H; Akagi, H; Masaru, Y; Otani, T; Hyodo, A; Hiramatsu, K

1995-01-01

TOC-39, a new parenteral cephalosporin, is a hydroxyimino-type cephem antibiotic with vinylthio-pyridyl moiety at the 3 position. TOC-39 was evaluated for antibacterial activity against various clinically isolated strains. TOC-39 had excellent activity, stronger than that of methicillin, oxacillin, the cephalosporins tested, imipenem, gentamicin, minocycline, tobramycin, ofloxacin, and ciprofloxacin against methicillin-resistant Staphylococcus aureus (MRSA) and had an MIC comparable to that of vancomycin (the MICs of TOC-39 and vancomycin for 90% of the strains tested were 3.13 and 1.56 micrograms/ml, respectively). Against Enterococcus faecalis strains, which are resistant to cephalosporins, TOC-39 was twice as active as ampicillin. Against methicillin-susceptible S. aureus, coagulase-negative Staphylococcus spp., and Streptococcus pneumoniae, TOC-39 was twice as active as or more active than cefotiam, ceftazidime, flomoxef, and cefpirome. Against Streptococcus pyogenes, TOC-39 was superior to cefotiam, ceftazidime, and flomoxef and was similar to cefpirome. In addition, the activity of TOC-39 was equal to or greater than that of cefotiam, ceftazidime, flomoxef, and cefpirome against Haemophilus influenzae, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Morganella morganii. In terms of bactericidal effect against MRSA, TOC-39 was superior to vancomycin. No mutant resistant to TOC-39 or vancomycin was obtained from susceptible MRSA strains. In murine systemic infection models, TOC-39 showed potent activity against S. aureus and E. coli. Against highly MRSA, the activity of TOC-39 was comparable to that of vancomycin. PMID:7625799

Epidemiology of Resistant Microbial Strains Among Different Groups of People (Healthy, Infected and Exposed to Animals)

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2017-11-10

ESBL Producing E.Coli; ESBL Producing K.Pneumoniae; Multidrug Resistant P.Aeruginosa; Carbapenem Resistant P.Aeruginosa; Methicillin Resistant Staphylococcus Aureus (MRSA); Vancomycin (Glycopeptide) Resistant Enterococcus (VRE)

Cross-transmission of vancomycin-resistant Enterococcus in patients undergoing dialysis and kidney transplant

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D. Fram

2010-01-01

Full Text Available The objective of this study was to investigate the occurrence of vancomycin-resistant Enterococcus (VRE cross-transmission between two patient groups (long-term dialysis and kidney transplant patients. Molecular typing, by automated ribotyping with the RiboPrinter Microbial Characterization System (Qualicon, USA, was used to analyze VRE isolates from 31 fecal samples of 320 dialysis patients and 38 fecal samples of 280 kidney transplant patients. Clonal spread of E. faecalis and E. casseliflavus was observed intragroup, but not between the two groups of patients. In turn, transmission of E. gallinarum and E. faecium between the groups was suggested by the finding of vancomycin-resistant isolates belonging to the same ribogroup in both dialysis and transplant patients. The fact that these patients were colonized by VRE from the same ribogroup in the same health care facility provides evidence for cross-transmission and supports the adoption of stringent infection control measures to prevent dissemination of these bacteria.

Dispersion of the vancomycin resistance genes vanA and vanC of Enterococcus isolated from Nile tilapia on retail sale: A public health hazard

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Kamelia Mahmoud Osman

2016-08-01

Full Text Available Although normally regarded harmless commensals, enterococci may cause a range of different infections in humans, including urinary tract infections, sepsis, and endocarditis. The acquisition of vancomycin resistance by enterococci (VRE has seriously affected the treatment and infection control of these organisms. VRE are frequently resistant to all antibiotics that are effective treatment for vancomycin-susceptible enterococci, which leaves clinicians treating VRE infections with limited therapeutic options. With VRE emerging as a global threat to public health, we aimed to isolate, identify enterococci species from tilapia and their resistance to van-mediated glycopeptide (vanA and vanC as well as the presence of enterococcal surface protein (esp using conventional and molecular methods. The cultural, biochemical (Vitek 2 system and PCR results revealed eight Enterococcus isolates from the 80 fish samples (10% to be further identified as E. faecalis (6/8, 75% and E gallinarum (2/8, 25%. Intraperitoneal injection of healthy Nile tilapia with the eight Enterococcus isolates caused significant morbidity (70% within 3 days and 100% mortality at 6 days post injection with general signs of septicemia. All of the eight Enterococcus isolates were found to be resistant to tetracycline. The 6/6 E. faecalis isolates were susceptible for penicillin, nitrofurantoin, gentamicin, and streptomycin. On the other hand 5/6 were susceptible for ampicillin, vancomycin, chloramphenicol and ciprofloxacin. The two isolates of E. gallinarum were sensitive to rifampicin and ciprofloxacin and resistant to vancomycin, chloramphenicol and erythromycin. Molecular characterization proved that they all presented the prototypic vanC element. On the whole, one of the two vancomycin resistance gene was present in 3/8 of the enterococci isolates, while the esp virulence gene was present in 1/8 of the enterococci isolates. The results in this study emphasise the potential role

Tedizolid susceptibility in linezolid- and vancomycin-resistant Enterococcus faecium isolates.

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Klupp, E-M; Both, A; Belmar Campos, C; Büttner, H; König, C; Christopeit, M; Christner, M; Aepfelbacher, M; Rohde, H

2016-12-01

Vancomycin-resistant enterococci (VRE) are of ever-increasing importance, most notably in high-risk patient populations. Therapy options are often limited for these isolates, and apart from tigecycline and daptomycin, oxazolidinone linezolid is frequently administered. The broad usage of linezolid, however, has driven the emergence of linezolid-resistant VRE strains (LR-VRE), further shortening therapeutic options. Second-generation oxazolidinone tedizolid has the advantage of being active against a specific subset of LR-VRE, i.e. isolates expressing the plasmid-encoded chloramphenicol-florfenicol resistance (cfr) gene. Here we tested tedizolid activity in a collection of 30 LR Enterococcus faecium VRE (MIC range 32-256 mg/l) isolated between 2012 and 2015 from clinical and screening specimens. By pulsed field gel electrophoresis (PFGE) isolates were assigned to 16 clonal lineages. In three cases, linezolid-susceptible progenitor isolates of LR-VRE were isolated, thus demonstrating the de-novo emergence of the linezolid-resistant phenotype. PCR did not detect cfr, cfr(B) or novel oxazolidinone resistance gene optrA in LR-VRE. All isolates, however, carried mutations within the 23S rDNA. Compared to linezolid, tedizolid MICs were lower in all isolates (MIC range 2-32 mg/l), but remained above the FDA tedizolid breakpoint for E. faecalis at 0.5 mg/l. Thus, related to the predominant resistance mechanism, tedizolid is of limited value for treatment of most LR-VRE and represents a therapeutic option only for a limited subset of isolates.

Relationship between Vancomycin-Resistant Staphylococcus aureus, Vancomycin-Intermediate S. aureus, High Vancomycin MIC, and Outcome in Serious S. aureus Infections

OpenAIRE

Holmes, Natasha E.; Johnson, Paul D. R.; Howden, Benjamin P.

2012-01-01

Vancomycin has been used successfully for over 50 years for the treatment of Staphylococcus aureus infections, particularly those involving methicillin-resistant S. aureus. It has proven remarkably reliable, but its efficacy is now being questioned with the emergence of strains of S. aureus that display heteroresistance, intermediate resistance, and, occasionally, complete vancomycin resistance. More recently, an association has been established between poor outcome and infections with strain...

Novel Inhibitors of Staphyloxanthin Virulence Factor in Comparison with Linezolid and Vancomycin versus Methicillin-Resistant, Linezolid-Resistant, and Vancomycin-Intermediate Staphylococcus aureus Infections in Vivo.

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Ni, Shuaishuai; Wei, Hanwen; Li, Baoli; Chen, Feifei; Liu, Yifu; Chen, Wenhua; Xu, Yixiang; Qiu, Xiaoxia; Li, Xiaokang; Lu, Yanli; Liu, Wenwen; Hu, Linhao; Lin, Dazheng; Wang, Manjiong; Zheng, Xinyu; Mao, Fei; Zhu, Jin; Lan, Lefu; Li, Jian

2017-10-12

Our previous work ( Wang et al. J. Med. Chem. 2016 , 59 , 4831 - 4848 ) revealed that effective benzocycloalkane-derived staphyloxanthin inhibitors against methicillin-resistant Staphylococcus aureus (S. aureus) infections were accompanied by poor water solubility and high hERG inhibition and dosages (preadministration). In this study, 92 chroman and coumaran derivatives as novel inhibitors have been addressed for overcoming deficiencies above. Derivatives 69 and 105 displayed excellent pigment inhibitory activities and low hERG inhibition, along with improvement of solubility by salt type selection. The broad and significantly potent antibacterial spectra of 69 and 105 were displayed first with normal administration in the livers and hearts in mice against pigmented S. aureus Newman, Mu50 (vancomycin-intermediate S. aureus), and NRS271 (linezolid-resistant S. aureus), compared with linezolid and vancomycin. In summary, both 69 and 105 have the potential to be developed as good antibacterial candidates targeting virulence factors.

Intestinal Microbiota Containing Barnesiella Species Cures Vancomycin-Resistant Enterococcus faecium Colonization

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Bucci, Vanni; Caballero, Silvia; Djukovic, Ana; Toussaint, Nora C.; Equinda, Michele; Lipuma, Lauren; Ling, Lilan; Gobourne, Asia; No, Daniel; Taur, Ying; Jenq, Robert R.; van den Brink, Marcel R. M.; Xavier, Joao B.

2013-01-01

Bacteria causing infections in hospitalized patients are increasingly antibiotic resistant. Classical infection control practices are only partially effective at preventing spread of antibiotic-resistant bacteria within hospitals. Because the density of intestinal colonization by the highly antibiotic-resistant bacterium vancomycin-resistant Enterococcus (VRE) can exceed 109 organisms per gram of feces, even optimally implemented hygiene protocols often fail. Decreasing the density of intestinal colonization, therefore, represents an important approach to limit VRE transmission. We demonstrate that reintroduction of a diverse intestinal microbiota to densely VRE-colonized mice eliminates VRE from the intestinal tract. While oxygen-tolerant members of the microbiota are ineffective at eliminating VRE, administration of obligate anaerobic commensal bacteria to mice results in a billionfold reduction in the density of intestinal VRE colonization. 16S rRNA gene sequence analysis of intestinal bacterial populations isolated from mice that cleared VRE following microbiota reconstitution revealed that recolonization with a microbiota that contains Barnesiella correlates with VRE elimination. Characterization of the fecal microbiota of patients undergoing allogeneic hematopoietic stem cell transplantation demonstrated that intestinal colonization with Barnesiella confers resistance to intestinal domination and bloodstream infection with VRE. Our studies indicate that obligate anaerobic bacteria belonging to the Barnesiella genus enable clearance of intestinal VRE colonization and may provide novel approaches to prevent the spread of highly antibiotic-resistant bacteria. PMID:23319552

Antimicrobial growth promoter ban and resistance to macrolides and vancomycin in enterococci from pigs

DEFF Research Database (Denmark)

Boerlin, P.; Wissing, A.; Aarestrup, Frank Møller

2001-01-01

Ninety-six enterococcus isolates from fecal samples of pigs receiving tylosin as an antimicrobial growth promoter and 59 isolates obtained in the same farms 5 to 6 months after the ban of antimicrobial growth promoters in Switzerland were tested for susceptibility to nine antimicrobial agents....... A clear decrease in resistance to macrolides, lincosamides, and tetracycline was visible after the ban. Vancomycin-resistant Enterococcus faecium belonged to the same clonal lineage as vancomycin-resistant isolates previously isolated from Danish pigs....

Minimum inhibitory concentration of vancomycin to methicillin resistant Staphylococcus aureus isolated from different clinical samples at a tertiary care hospital in Nepal

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Arjun Ojha Kshetry

2016-07-01

Full Text Available Abstract Background Methicillin resistant Staphylococcus aureus (MRSA has evolved as a serious threat to public health. It has capability to cause infections not only in health care settings but also in community. Due to the multidrug resistance shown by MRSA, there are limited treatment options for the infections caused by this superbug. Vancomycin is used as the drug of choice for the treatment of infections caused by MRSA. Different studies from all around the world have documented the emergence of strains of S. aureus those are intermediate sensitive or resistant to vancomycin. And recently, there have been reports of reduced susceptibility of MRSA to vancomycin, from Nepal also. So the main purpose of this study was to determine the minimum inhibitory concentration (MIC of vancomycin to methicillin resistant S. aureus isolated from different clinical specimens. Methods Total 125 strains of S. aureus isolated from different clinical samples at KIST Medical College and Teaching Hospital, Lalitpur, Nepal from Nov 2012 to June 2013, were subjected to MRSA detection by cefoxitin disc diffusion method. The minimum inhibitory concentrations of vancomycin to confirmed MRSA strains were determined by agar dilution method. Yellow colored colonies in mannitol salt agar, which were gram positive cocci, catalase positive and coagulase positive were confirmed to be S. aureus. Results Among, total 125 S. aureus strains isolated; 47(37.6% were MRSA. Minimum inhibitory concentrations of vancomycin to the strains of MRSA ranged from 0.125 μg/ml to 1 μg/ml. Conclusion From our findings we concluded that the rate of isolation of MRSA among all the strains of S. aureus isolated from clinical samples was very high. However, none of the MRSA strains were found to be vancomycin intermediate-sensitive or vancomycin-resistant.

Outbreak of vancomycin-resistant Enterococcus faecium in a haematology unit: risk factor assessment and successful control of the epidemic

NARCIS (Netherlands)

Timmers, Gert Jan; van der Zwet, Wil C.; Simoons-Smit, Ina M.; Savelkoul, Paul H. M.; Meester, Helena H. M.; Vandenbroucke-Grauls, Christina M. J. E.; Huijgens, Peter C.

2002-01-01

We describe an outbreak of vancomycin-resistant Enterococcus faecium (VRE) on the haematology ward of a Dutch university hospital. After the occurrence of three consecutive cases of bacteraemia with VRE, strains were genotyped and found to be identical. During the next 4 months an intensive

Novel antiseptic compound OPB-2045G shows potent bactericidal activity against methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus both in vitro and in vivo: a pilot study in animals.

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Inoue, Yasuhide; Hagi, Akifumi; Nii, Takuya; Tsubotani, Yoshie; Nakata, Hikaru; Iwata, Koushi

2015-01-01

There is a need for new compounds to effectively treat methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). The novel monobiguanide compound 1-(3,4-dichlorobenzyl)-5-octylbiguanide gluconate (OPB-2045G) has potential bactericidal activity. We sought to elucidate the potency of OPB-2045G bactericidal activity against MRSA and VRE compared to those of chlorhexidine digluconate (CHG) and povidone iodine (PVP-I). In vitro bactericidal activity was analysed using minimum bactericidal concentration (MBC) as the index. The in vivo bactericidal efficacy of OPB-2045G was examined by determining MRSA and VRE contamination of the normal dorsal skin of mice following removal of hair. After a 3 min treatment period, the MBC of OPB-2045G was lower than that of CHG and PVP-I against standard strains and clinical isolates. Additionally, in our in vivo mouse model, the in vivo bactericidal activity of 1.5 % OPB-2045G (a clinically relevant dose) was higher than that of 0.5 % CHG and equivalent to that of 10 % PVP-I against MRSA. Similarly, the in vivo bactericidal activity of OPB-2045G was higher than that of 0.5 % CHG and 10 % PVP-I against VRE. OPB-2045G showed more potent bactericidal activity against MRSA and VRE both in vitro and in vivo compared to CHG and PVP-I, indicating that OPB-2045G may provide better protection against health care-associated infections caused by these pathogens. © 2015 The Authors.

Vancomycin resistant enterococci in urine cultures: Antibiotic susceptibility trends over a decade at a tertiary hospital in the United Kingdom.

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Toner, Liam; Papa, Nathan; Aliyu, Sani H; Dev, Harveer; Lawrentschuk, Nathan; Al-Hayek, Samih

2016-03-01

Enterococci are a common cause of urinary tract infection and vancomycin-resistant strains are more difficult to treat. The purpose of this surveillance program was to assess the prevalence of and determine the risk factors for vancomycin resistance in adults among urinary isolates of Enterococcus sp. and to detail the antibiotic susceptibility profile, which can be used to guide empirical treatment. From 2005 to 2014 we retrospectively reviewed 5,528 positive Enterococcus sp. urine cultures recorded in a computerized laboratory results database at a tertiary teaching hospital in Cambridge, United Kingdom. Of these cultures, 542 (9.8%) were vancomycin resistant. No longitudinal trend was observed in the proportion of vancomycin-resistant strains over the course of the study. We observed emerging resistance to nitrofurantoin with rates climbing from near zero to 40%. Ampicillin resistance fluctuated between 50% and 90%. Low resistance was observed for linezolid and quinupristin/dalfopristin. Female sex and inpatient status were identified as risk factors for vancomycin resistance. The incidence of vancomycin resistance among urinary isolates was stable over the last decade. Although resistance to nitrofurantoin has increased, it still serves as an appropriate first choice in uncomplicated urinary tract infection caused by vancomycin-resistant Enterococcus sp.

Vancomycin resistant enterococci in urine cultures: Antibiotic susceptibility trends over a decade at a tertiary hospital in the United Kingdom

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Liam Toner

2016-03-01

Full Text Available Purpose: Enterococci are a common cause of urinary tract infection and vancomycin-resistant strains are more difficult to treat. The purpose of this surveillance program was to assess the prevalence of and determine the risk factors for vancomycin resistance in adults among urinary isolates of Enterococcus sp. and to detail the antibiotic susceptibility profile, which can be used to guide empirical treatment. Materials and Methods: From 2005 to 2014 we retrospectively reviewed 5,528 positive Enterococcus sp. urine cultures recorded in a computerized laboratory results database at a tertiary teaching hospital in Cambridge, United Kingdom. Results: Of these cultures, 542 (9.8% were vancomycin resistant. No longitudinal trend was observed in the proportion of vancomycin- resistant strains over the course of the study. We observed emerging resistance to nitrofurantoin with rates climbing from near zero to 40%. Ampicillin resistance fluctuated between 50% and 90%. Low resistance was observed for linezolid and quinupristin/ dalfopristin. Female sex and inpatient status were identified as risk factors for vancomycin resistance. Conclusions: The incidence of vancomycin resistance among urinary isolates was stable over the last decade. Although resistance to nitrofurantoin has increased, it still serves as an appropriate first choice in uncomplicated urinary tract infection caused by vancomycin- resistant Enterococcus sp.

Detection of vancomycin resistances in enterococci within 3 1/2 hours

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Schröder, U. -Ch.; Beleites, C.; Assmann, C.; Glaser, U.; Hübner, U.; Pfister, W.; Fritzsche, W.; Popp, J.; Neugebauer, U.

2015-02-01

Vancomycin resistant enterococci (VRE) constitute a challenging problem in health care institutions worldwide. Novel methods to rapidly identify resistances are highly required to ensure an early start of tailored therapy and to prevent further spread of the bacteria. Here, a spectroscopy-based rapid test is presented that reveals resistances of enterococci towards vancomycin within 3.5 hours. Without any specific knowledge on the strain, VRE can be recognized with high accuracy in two different enterococci species. By means of dielectrophoresis, bacteria are directly captured from dilute suspensions, making sample preparation very easy. Raman spectroscopic analysis of the trapped bacteria over a time span of two hours in absence and presence of antibiotics reveals characteristic differences in the molecular response of sensitive as well as resistant Enterococcus faecalis and Enterococcus faecium. Furthermore, the spectroscopic fingerprints provide an indication on the mechanisms of induced resistance in VRE.

Methicillin resistant Staphylococcus aureus in Ethiopia: a meta-analysis.

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Eshetie, Setegn; Tarekegn, Fentahun; Moges, Feleke; Amsalu, Anteneh; Birhan, Wubet; Huruy, Kahsay

2016-11-21

The burden of methicillin resistant Staphylococcus aureus is a major public health concern worldwide; however the overall epidemiology of multidrug resistant strains is neither coordinated nor harmonized, particularly in developing countries including Ethiopia. Therefore, the aim of this meta-analysis was to assess the burden of methicillin resistant Staphylococcos aureus and its antibiotic resistance pattern in Ethiopia at large. PubMed, Google Scholar, and lancet databases were searched and a total of 20 studies have been selected for meta-analysis. Six authors have independently extracts data on the prevalence of methicillin resistant Staphylococcus aureus among clinical isolates of Staphylococcus aureus. Statistical analysis was achieved by using Open meta-analyst (version 3.13) and Comprehensive meta-analysis (version 3.3) softwares. The overall prevalence of methicillin resistant Staphylococcus aureus and its antibiotic resistance pattern were pooled by using the forest plot, table and figure with 95% CI. The pooled prevalence of methicillin resistant Staphylococcus aureus was 32.5% (95% CI, 24.1 to 40.9%). Moreover, methicillin resistant Staphylococcus aureus strains were found to be highly resistant to penicillin, ampicillin, erythromycin, and amoxicillin, with a pooled resistance ratio of 99.1, 98.1, 97.2 and 97.1%, respectively. On the other hand, comparably low levels of resistance ratio were noted to vancomycin, 5.3%. The overall burden of methicillin resistant Staphylococcus aureus is considerably high, besides these strains showed extreme resistance to penicillin, ampicillin, erythromycin and amoxicillin. In principle, appropriate use of antibiotics, applying safety precautions are the key to reduce the spread of multidrug resistant strains, methicillin resistant Staphylococcus aureus in particular.

Does vancomycin prescribing intervention affect vancomycin-resistant enterococcus infection and colonization in hospitals? A systematic review

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Riley Lee W

2007-04-01

Full Text Available Abstract Background Vancomycin resistant enterococcus (VRE is a major cause of nosocomial infections in the United States and may be associated with greater morbidity, mortality, and healthcare costs than vancomycin-susceptible enterococcus. Current guidelines for the control of VRE include prudent use of vancomycin. While vancomycin exposure appears to be a risk factor for VRE acquisition in individual patients, the effect of vancomycin usage at the population level is not known. We conducted a systematic review to determine the impact of reducing vancomycin use through prescribing interventions on the prevalence and incidence of VRE colonization and infection in hospitals within the United States. Methods To identify relevant studies, we searched three electronic databases, and hand searched selected journals. Thirteen studies from 12 articles met our inclusion criteria. Data were extracted and summarized for study setting, design, patient characteristics, types of intervention(s, and outcome measures. The relative risk, 95% confidence interval, and p-value associated with change in VRE acquisition pre- and post-vancomycin prescription interventions were calculated and compared. Heterogeneity in study results was formally explored by stratified analysis. Results No randomized clinical trials on this topic were found. Each of the 13 included studies used a quasi-experimental design of low hierarchy. Seven of the 13 studies reported statistically significant reductions in VRE acquisition following interventions, three studies reported no significant change, and three studies reported increases in VRE acquisition, one of which reported statistical significance. Results ranged from a reduction of 82.5% to an increase of 475%. Studies of specific wards, which included sicker patients, were more likely to report positive results than studies of an entire hospital including general inpatients (Fisher's exact test 0.029. The type of intervention

Occurrence of vancomycin-resistant and -susceptible Enterococcus spp. in reclaimed water used for spray irrigation

Energy Technology Data Exchange (ETDEWEB)

Carey, Stephanie Ann; Goldstein, Rachel E. Rosenberg [Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD (United States); Gibbs, Shawn G. [Department of Environmental Health, School of Public Health-Bloomington, Indiana University, Bloomington, IN (United States); Claye, Emma [Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD (United States); He, Xin [Department of Epidemiology and Biostatistics, University of Maryland School of Public Health, College Park, MD (United States); Sapkota, Amy R., E-mail: ars@umd.edu [Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD (United States)

2016-05-15

Reclaiming municipal wastewater for agricultural, environmental, and industrial purposes is increasing in the United States to combat dwindling freshwater supplies. However, there is a lack of data regarding the microbial quality of reclaimed water. In particular, no previous studies have evaluated the occurrence of vancomycin-resistant enterococci (VRE) in reclaimed water used at spray irrigation sites in the United States. To address this knowledge gap, we investigated the occurrence, concentration, and antimicrobial resistance patterns of VRE and vancomycin-susceptible enterococci at three U.S. spray irrigation sites that use reclaimed water. We collected 48 reclaimed water samples from one Mid-Atlantic and two Midwest spray irrigation sites, as well as their respective wastewater treatment plants, in 2009 and 2010. Samples were analyzed for total enterococci and VRE using standard membrane filtration. Isolates were purified and then confirmed using biochemical tests and PCR. Antimicrobial susceptibility testing was conducted using the Sensititre® microbroth dilution system. Data were analyzed by two-sample proportion tests and one-way analysis of variance. We detected total enterococci and VRE in 71% (34/48) and 4% (2/48) of reclaimed water samples, respectively. Enterococcus faecalis was the most common species identified. At the Mid-Atlantic spray irrigation site, UV radiation decreased total enterococci to undetectable levels; however, subsequent storage in an open-air pond at this site resulted in increased concentrations of enterococci. E. faecalis isolates recovered from the Mid-Atlantic spray irrigation site expressed intrinsic resistance to quinupristin/dalfopristin; however, non-E. faecalis isolates expressed resistance to quinupristin/dalfopristin (52% of isolates), vancomycin (4%), tetracycline (13%), penicillin (4%) and ciprofloxacin (17%). Our findings show that VRE are present in low numbers in reclaimed water at point-of-use at the sampled spray

Occurrence of vancomycin-resistant and -susceptible Enterococcus spp. in reclaimed water used for spray irrigation

International Nuclear Information System (INIS)

Carey, Stephanie Ann; Goldstein, Rachel E. Rosenberg; Gibbs, Shawn G.; Claye, Emma; He, Xin; Sapkota, Amy R.

2016-01-01

Reclaiming municipal wastewater for agricultural, environmental, and industrial purposes is increasing in the United States to combat dwindling freshwater supplies. However, there is a lack of data regarding the microbial quality of reclaimed water. In particular, no previous studies have evaluated the occurrence of vancomycin-resistant enterococci (VRE) in reclaimed water used at spray irrigation sites in the United States. To address this knowledge gap, we investigated the occurrence, concentration, and antimicrobial resistance patterns of VRE and vancomycin-susceptible enterococci at three U.S. spray irrigation sites that use reclaimed water. We collected 48 reclaimed water samples from one Mid-Atlantic and two Midwest spray irrigation sites, as well as their respective wastewater treatment plants, in 2009 and 2010. Samples were analyzed for total enterococci and VRE using standard membrane filtration. Isolates were purified and then confirmed using biochemical tests and PCR. Antimicrobial susceptibility testing was conducted using the Sensititre® microbroth dilution system. Data were analyzed by two-sample proportion tests and one-way analysis of variance. We detected total enterococci and VRE in 71% (34/48) and 4% (2/48) of reclaimed water samples, respectively. Enterococcus faecalis was the most common species identified. At the Mid-Atlantic spray irrigation site, UV radiation decreased total enterococci to undetectable levels; however, subsequent storage in an open-air pond at this site resulted in increased concentrations of enterococci. E. faecalis isolates recovered from the Mid-Atlantic spray irrigation site expressed intrinsic resistance to quinupristin/dalfopristin; however, non-E. faecalis isolates expressed resistance to quinupristin/dalfopristin (52% of isolates), vancomycin (4%), tetracycline (13%), penicillin (4%) and ciprofloxacin (17%). Our findings show that VRE are present in low numbers in reclaimed water at point-of-use at the sampled spray

In Vitro Synergistic Effects of Double and Triple Combinations of β-Lactams, Vancomycin, and Netilmicin against Methicillin-Resistant Staphylococcus aureus Strains

Science.gov (United States)

Rochon-Edouard, Stéphanie; Pestel-Caron, Martine; Lemeland, Jean-François; Caron, François

2000-01-01

Several studies have previously reported synergistic effects between vancomycin and a given β-lactam or a given aminoglycoside against methicillin-resistant Staphylococcus aureus (MRSA) strains. The aim of our study was to exhaustively compare the effects of different combinations of a β-lactam, vancomycin, and/or an aminoglycoside against 32 clinical MRSA strains with different aminoglycoside susceptibility patterns. The effects of 26 different β-lactam–vancomycin and 8 different aminoglycoside-vancomycin combinations were first studied using a disk diffusion screening method. The best interactions with vancomycin were observed with either imipenem, cefazolin, or netilmicin. By checkerboard studies, imipenem-vancomycin and cefazolin-vancomycin each provided a synergistic bacteriostatic effect against 22 strains; the mean fractional inhibitory concentration (FIC) indexes were 0.35 and 0.46 for imipenem-vancomycin and cefazolin-vancomycin, respectively. The vancomycin-netilmicin combination provided an indifferent effect against all of the 32 strains tested; the mean of FIC index was 1.096. The mean concentrations of imipenem, cefazolin, netilmicin, and vancomycin at which FIC indexes were calculated were clinically achievable. Killing experiments were then performed using imipenem, cefazolin, netilmicin, and vancomycin at one-half of the MIC, alone and in different combinations, against 10 strains. The vancomycin-netilmicin regimen was rarely bactericidal, even against strains susceptible to netilmicin. The imipenem-vancomycin and cefazolin-vancomycin combinations were strongly bactericidal against six and five strains, respectively. The addition of netilmicin markedly enhanced the killing activity of the combination of cefazolin or imipenem plus vancomycin, but only for the MRSA strains against which the β-lactam–vancomycin combinations had no bactericidal effect. It is noteworthy that the latter strains were both susceptible to netilmicin and

Empiric guideline-recommended weight-based vancomycin dosing and mortality in methicillin-resistant Staphylococcus aureus bacteremia: a retrospective cohort study

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Hall Ronald G

2012-04-01

Full Text Available Abstract Background No studies have evaluated the effect of guideline-recommended weight-based dosing on in-hospital mortality of patients with methicillin-resistant Staphylococcus aureus bacteremia. Methods This was a multicenter, retrospective, cohort study of patients with methicillin-resistant Staphylococcus aureus bacteremia receiving at least 48 hours of empiric vancomycin therapy between 01/07/2002 and 30/06/2008. We compared in-hospital mortality for patients treated empirically with weight-based, guideline-recommended vancomycin doses (at least 15 mg/kg/dose to those treated with less than 15 mg/kg/dose. We used a general linear mixed multivariable model analysis with variables identified a priori through a conceptual framework based on the literature. Results A total of 337 patients who were admitted to the three hospitals were included in the cohort. One-third of patients received vancomycin empirically at the guideline-recommended dose. Guideline-recommended dosing was not associated with in-hospital mortality in the univariable (16% vs. 13%, OR 1.26 [95%CI 0.67-2.39] or multivariable (OR 0.71, 95%CI 0.33-1.55 analysis. Independent predictors of in-hospital mortality were ICU admission, Pitt bacteremia score of 4 or greater, age 53 years or greater, and nephrotoxicity. Conclusions Empiric use of weight-based, guideline-recommended empiric vancomycin dosing was not associated with reduced mortality in this multicenter study.

CLINICAL ISOLATES OF MECA, METHICILLIN, VANCOMYCIN RESISTANCE S. AUREUS; ESBLs PRODUCING K.PNEUMONIA, E.COLI, P. AUREGENOSA FROM VARIOUS CLINICAL SOURCE AND ITS ANTIMICROBIAL RESISTANCE PATTERNS

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Ismail Mahmud Ali, Amirthalingam R

2015-01-01

Full Text Available Background and Objective: Antimicrobial resistance has turned into a key medical and public health crisis globally since the injudicious use of magic bullets (drugs. Aim of this study is focused on the clinical isolate and their percentages of resistant to antibiotics in gram positive bacteria such as MRSA, VRSA, and MSSA are common causes of nosocomical, skin structure infections, bacteremia and infection of other systems; ESBLs producing Enterobacteriaceae (E. coli, Klebsiella spp. is common agent of urinary tract, bloodstream, pulmonary and intra-abdominal infections and carbapenem resistant P. aeruginosa with its complete antimicrobial patterns which are currently practiced in this population. Methods: There are one hundred and fourteen (114 various clinical isolates, isolated from various clinical samples like throat swab, urine, pus, sputum, and blood culture, identified as specific isolate with resistance patterns were analyzed by BD phoenix-100 the auto analyzer. Results: Off 114 clinical isolate, 6 mecA-mediated resistance (cefoxitin>8mgc/ml, 11 methicillin resistance, 18 β lactam/βlactamase inhibitor, 12 methicillin sensitive and 3 vancomycin (>16µg/ml resistance S. aureus have been isolated from overall 50 isolate of S.aureus. In addition, there are 27 P.aeruginosa, 15 ESBLs from overall of 25 K. pneumoniae and 7 ESBLs out of 12 Escherichia coli species have been isolated. The resistance and susceptibility pattern percentages have been graphically represented for each isolates. Conclusion: Current study revealed that the drug classes of β lactam/βlactamase inhibitor having high resistance rate with S.aureus, P.aureginosa, K. pneumoniae and E. coli isolate. Also, some of other drug classes such as cepham and tetracycline having higher resistance rate with P.aureginosa and K.pneumoniae. In addition, the vancomycin resistances S. aureus have been isolated and reported as first time in this population.

Vancomycin-resistant enterococcus outbreak in a pediatric intensive care unit: report of successful interventions for control and prevention

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F. Carmona

2012-02-01

Full Text Available The objective of this study is to retrospectively report the results of interventions for controlling a vancomycin-resistant enterococcus (VRE outbreak in a tertiary-care pediatric intensive care unit (PICU of a University Hospital. After identification of the outbreak, interventions were made at the following levels: patient care, microbiological surveillance, and medical and nursing staff training. Data were collected from computer-based databases and from the electronic prescription system. Vancomycin use progressively increased after March 2008, peaking in August 2009. Five cases of VRE infection were identified, with 3 deaths. After the interventions, we noted a significant reduction in vancomycin prescription and use (75% reduction, and the last case of VRE infection was identified 4 months later. The survivors remained colonized until hospital discharge. After interventions there was a transient increase in PICU length-of-stay and mortality. Since then, the use of vancomycin has remained relatively constant and strict, no other cases of VRE infection or colonization have been identified and length-of-stay and mortality returned to baseline. In conclusion, we showed that a bundle intervention aiming at a strict control of vancomycin use and full compliance with the Hospital Infection Control Practices Advisory Committee guidelines, along with contact precautions and hand-hygiene promotion, can be effective in reducing vancomycin use and the emergence and spread of vancomycin-resistant bacteria in a tertiary-care PICU.

Antimicrobial resistance profile of Enterococcus spp isolated from food in Southern Brazil

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Riboldi, Gustavo Pelicioli; Frazzon, Jeverson; d’Azevedo, Pedro Alves; Frazzon, Ana Paula Guedes

2009-01-01

Fifty-six Enterococcus spp. strains were isolated from foods in Southern Brazil, confirmed by PCR and classified as Enterococcus faecalis (27), Enterococcus faecium (23) and Enterococcus spp (6). Antimicrobial susceptibility tests showed resistance phenotypes to a range of antibiotics widely administrated in humans such as gentamycin, streptomycin, ampicillin and vancomycin. PMID:24031330

Analysis of the world epidemiological situation among vancomycin-resistant Enterococcus faecium infections and the current situation in Poland

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Talaga-Ćwiertnia, Katarzyna; Bulanda, Małgorzata

2018-01-01

Vancomycin-resistant Enterococcus faecium (VREfm) strains have become an important hospital pathogen due to their rapid spread, high mortality rate associated with infections and limited therapeutic options. Vancomycin resistance is predominantly mediated by VanA or VanB phenotypes, which differ as regards maintaining sensitivity to teicoplanin in the VanB phenotype. The majority of VREfm cases in the United States, Europe, Korea, South America and Africa are currently caused by the VanA phenotype. However, the epidemics in Australia and Singapore are chiefly brought about by the VanB phenotype. The rate of VREfm isolate spread varies greatly. The greatest percentage of VREfm is now recorded in the USA, Ireland and Australia. Supervision of VRE is implemented to varying degrees. Therefore, the epidemiological situation in some countries is difficult to assess due to limited data or lack thereof.

Genetic pathway in acquisition and loss of vancomycin resistance in a methicillin resistant Staphylococcus aureus (MRSA strain of clonal type USA300.

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Susana Gardete

2012-02-01

Full Text Available An isolate of the methicillin-resistant Staphylococcus aureus (MRSA clone USA300 with reduced susceptibility to vancomycin (SG-R (i.e, vancomycin-intermediate S. aureus, VISA and its susceptible "parental" strain (SG-S were recovered from a patient at the end and at the beginning of an unsuccessful vancomycin therapy. The VISA phenotype was unstable in vitro generating a susceptible revertant strain (SG-rev. The availability of these 3 isogenic strains allowed us to explore genetic correlates of antibiotic resistance as it emerged in vivo. Compared to the susceptible isolate, both the VISA and revertant strains carried the same point mutations in yycH, vraG, yvqF and lspA genes and a substantial deletion within an intergenic region. The revertant strain carried a single additional frameshift mutation in vraS which is part of two component regulatory system VraSR. VISA isolate SG-R showed complex alterations in phenotype: decreased susceptibility to other antibiotics, slow autolysis, abnormal cell division and increased thickness of cell wall. There was also altered expression of 239 genes including down-regulation of major virulence determinants. All phenotypic properties and gene expression profile returned to parental levels in the revertant strain. Introduction of wild type yvqF on a multicopy plasmid into the VISA strain caused loss of resistance along with loss of all the associated phenotypic changes. Introduction of the wild type vraSR into the revertant strain caused recovery of VISA type resistance. The yvqF/vraSR operon seems to function as an on/off switch: mutation in yvqF in strain SG-R turns on the vraSR system, which leads to increase in vancomycin resistance and down-regulation of virulence determinants. Mutation in vraS in the revertant strain turns off this regulatory system accompanied by loss of resistance and normal expression of virulence genes. Down-regulation of virulence genes may provide VISA strains with a "stealth

Estudio de actinomicetos marinos aislados de la costa central del Perú y su actividad antibacteriana frente a Staphylococcus aureus Meticilina Resistentes y Enterococcus faecalis Vancomicina Resistentes Study of marine actinomycetes isolated from the central coast of Peru and their antibacterial activity against Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococcus faecalis

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Jorge León

2011-06-01

Full Text Available Objetivos. Determinar el potencial antimicrobiano de actinomicetos marinos frente a cepas S. aureus meticilino-resistentes (MRSA y E. faecalis vancomicina-resistentes (VRE. Materiales y métodos. En dos medios de cultivo se sembraron 29 cepas de actinomicetos aislados de sedimento marino. Se evaluó la capacidad inhibitoria mediante pruebas de antagonismo in vitro para MRSA y VRE. Se procesó los extractos orgánicos de tres actinomicetos seleccionados para determinar la Concentración Mínima Inhibitoria (CMI del compuesto activo. Resultados. La mayoría de los actinomicetos aislados correspondieron a un grupo homogéneo de blanco-grisáceos (62% con buen nivel de crecimiento en agar marino. Los porcentajes inhibitorios fueron superiores a 85% para ambos patógenos con halos de inhibición mayores a 69 y 78 mm de diámetro para MRSA y VRE respectivamente. Los extractos diclorometánicos de tres de los actinomicetos aislados (I-400A, B1-T61, M10-77 mostraron gran potencial inhibitorio de ambos patógenos, siendo M10-77 la cepa de actinomiceto de mayor actividad antibiótica frente a S. aureus ATCC 43300 resistente a meticilina y E. faecalis ATCC 51299 resistente a vancomicina con una Concentración Mínima Inhibitoria (CMI de 7,9 y 31,7 μg/ mL respectivamente. El análisis filogenético de la cepa M10- 77 presenta un 99% de similaridad con la especie marina Streptomyces erythrogriseus. Conclusiones. El sedimento marino de la costa central del Perú es fuente promisorio de cepas de actinomicetos con gran capacidad de producir compuestos bioactivos capaces de inhibir patógenos tipificados como multidrogo-resistentes tales como S. aureus meticilino resistentes y E. faecalis vancomicina resistentes.Objectives. To determine the antimicrobial potential of marine actinomycetes against drug-resistant pathogens represented by strains of methicillin-resistant Staphylococcus aureus (MRSA and vancomycin-resistant Enterococcus faecalis (VRE. Materials and

Misidentification of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals in Tripoli, Libya

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Ahmed, Mohamed O.; Abuzweda, Abdulbaset R.; Alghazali, Mohamed H.; Elramalli, Asma K.; Amri, Samira G.; Aghila, Ezzeddin Sh.; Abouzeed, Yousef M.

2010-01-01

Background Methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial (hospital-acquired) pathogen of exceptional concern. It is responsible for life-threatening infections in both the hospital and the community. Aims To determine the frequency of MRSA misidentification in hospitals in Tripoli, Libya using current testing methods. Methods One hundred and seventy S. aureus isolates previously identified as MRSA were obtained from three hospitals in Tripoli. All isolates were reidentified by culturing on mannitol salt agar, API 20 Staph System and retested for resistance to methicillin using the cefoxitin disk diffusion susceptibility test and PBP2a. D-tests and vancomycin E-tests (Van-E-tests) were also performed for vancomycin-resistant isolates. Results Of the 170 isolates examined, 86 (51%) were confirmed as MRSA (i.e. 49% were misidentified as MRSA). Fifteen (17%) of the confirmed MRSA strains exhibited inducible clindamycin resistance. Of the 86 confirmed MRSA isolates, 13 (15%) were resistant to mupirocin, 53 (62%) were resistant to ciprofloxacin, 41 (48%) were resistant to trimethoprim-sulfamethoxazole, and none were resistant to linezolid. Although disc-diffusion testing indicated that 23 (27%) of the isolates were resistant to vancomycin, none of the isolates were vancomycin-resistant by Van-E-test. Conclusions Misidentification of nosocomial S. aureus as MRSA is a serious problem in Libyan hospitals. There is an urgent need for the proper training of microbiology laboratory technicians in standard antimicrobial susceptibility procedures and the implementation of quality control programs in microbiology laboratories of Libyan hospitals. PMID:21483574

Biotechnological Methods for Precise Diagnosis of Methicillin Resistance in Staphylococci

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Aija Zilevica

2005-04-01

Full Text Available Antimicrobial resistance is one of the most urgent problems in medicine nowadays. The purpose of the study was to investigate the microorganisms resistant to first-line antimicrobials, including gram-positive cocci, particularly the methicillin-resistant Staphylococcus aureus and coagulase-negative Staphylococci, the major agents of nosocomial infections. Owing to the multi-resistance of these agents, precise diagnosis of the methicillin resistance of Staphylococci is of greatest clinical importance. It is not enough to use only conventional microbiological diagnostic methods. Biotechnological methods should be also involved. In our studies, the following methicillin resistance identification methods were used: the disk diffusion method, detection of the mecA gene by PCR, E-test and Slidex MRSA test. For molecular typing, PFGL, RAPD tests and detection of the coa gene were used. All the MRS strains were multiresistant to antibacterials. No vancomycine resistance was registered.

Vancomycin resistant enterococci in farm animals – occurrence and importance

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Oskar Nilsson

2012-04-01

Full Text Available The view on enterococci has over the years shifted from harmless commensals to opportunistic but important pathogens mainly causing nosocomial infections. One important part of this development is the emergence of vancomycin resistance enterococci (VRE. The term VRE includes several combinations of bacterial species and resistance genes of which the most clinically important is Enterococcus faecium with vanA type vancomycin resistance. This variant is also the most common VRE among farm animals. The reason for VRE being present among farm animals is selection by extensive use of the vancomycin analog avoparcin for growth promotion. Once the use of avoparcin was discontinued, the prevalence of VRE among farm animals decreased. However, VRE are still present among farm animals and by spread via food products they could potentially have a negative impact on public health. This review is based on the PhD thesis Vancomycin Resistant Enterococci in Swedish Broilers – Emergence, Epidemiology and Elimination and makes a short summary of VRE in humans and food producing animals. The specific situation regarding VRE in Swedish broiler production is also mentioned.

Staphylococcal scalded skin syndrome in a premature newborn caused by methicillin-resistant Staphylococcus aureus: case report

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Andreas Hörner

Full Text Available CONTEXT: Staphylococcal scalded skin syndrome is an exfoliative skin disease. Reports of this syndrome in newborns caused by methicillin-resistant Staphylococcus aureus are rare but, when present, rapid diagnosis and treatment is required in order to decrease morbidity and mortality. CASE REPORT: A premature newly born girl weighing 1,520 g, born with a gestational age of 29 weeks and 4 days, developed staphylococcal scalded skin syndrome on the fifth day of life. Cultures on blood samples collected on the first and fourth days were negative, but Pseudomonas aeruginosa and Enterococcus sp. (vancomycin-sensitive developed in blood cultures performed on the day of death (seventh day, and Pseudomonas aeruginosa and Serratia marcescens were identified in cultures on nasopharyngeal, buttock and abdominal secretions. In addition to these two Gram-negative bacilli, methicillin-resistant Staphylococcus aureus was isolated in a culture on the umbilical stump (seventh day. The diagnosis of staphylococcal scalded skin syndrome was based on clinical criteria.

Molecular characterization of vancomycin-resistant Enterococcus faecium isolates from Bermuda.

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Patrick Eberechi Akpaka

Full Text Available Molecular characteristics of vancomycin resistant enterococci isolates from Bermuda Island is currently unknown. This study was conducted to investigate phenotypic and genotypic characteristics of VRE isolates from Bermuda Island using the chromogenic agar, E-tests, polymerase chain reaction (PCR, pulsed-field gel electrophoresis (PFGE and multilocus sequence typing (MLST. Eighteen E. faecium isolates were completely analyzed and were all resistant to vancomycin, susceptible to linezolid and quinupristin/dalfopristin, positive for vanA and esp genes. The MLST analysis confirmed most isolates were of the sequence types linked to clonal complex 17 (CC17 that is widely associated with outbreaks in hospitals. Infection control measures, antibiotic stewardship, and surveillance activities will continue to be a priority in hospital on the Island.

Human and Swine Hosts Share Vancomycin-Resistant Enterococcus faecium CC17 and CC5 and Enterococcus faecalis CC2 Clonal Clusters Harboring Tn1546 on Indistinguishable Plasmids

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Freitas, Ana R.; Coque, Teresa M.; Novais, Carla

2011-01-01

clonally related Enterococcus faecium clonal complex 5 (CC5) isolates (17 sequence type 6 [ST6], 6 ST5, 5 ST185, 1 ST147, and 1 ST493) were obtained from feces of swine and healthy humans. This collection included isolates widespread among pigs of European Union (EU) countries since the mid-1990s. Each ST...... comprised isolates showing similar pulsed-field gel electrophoresis (PFGE) patterns (≤6 bands difference; >82% similarity). Some CC5 PFGE subtype strains from swine were indistinguishable from hospital vancomycin-resistant enterococci (VRE) causing infections. A truncated variant of Tn1546 (encoding...... resistance to vancomycin) and tcrB (coding for resistance to copper) were consistently located on 150- to 190-kb plasmids (rep(pLG1)). E. faecium CC17 (ST132) isolates from pig manure and two clinical samples showed identical PFGE profiles and contained a 60-kb mosaic plasmid (rep(Inc18) plus rep...

Observed Antagonistic Effect of Linezolid on Daptomycin or Vancomycin Activity against Biofilm-Forming Methicillin-Resistant Staphylococcus aureus in an In Vitro Pharmacodynamic Model

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Luther, Megan K.

2015-01-01

Pharmacodynamic activity in antibiotic combinations of daptomycin, vancomycin, and linezolid was investigated in a 48-h in vitro pharmacodynamic model. Using human-simulated free drug concentrations, activity against clinical biofilm-forming methicillin-resistant Staphylococcus aureus isolates was evaluated. Linezolid antagonized vancomycin activity at 24 and 48 h. Linezolid antagonized daptomycin at 24 and 48 h depending on dose and strain. Adding daptomycin increased vancomycin activity at 48 h (P < 0.03). These results may be strain dependent and require further clinical investigation. PMID:26369963

Prevalence and Antimicrobial Resistance of Enterococcus Species: A Hospital-Based Study in China

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Wei Jia

2014-03-01

Full Text Available Objective: to investigate the prevalence and antimicrobial resistance of Enterococcus species isolated from a university hospital, and explore the mechanisms underlying the antimicrobial resistance, so as to provide clinical evidence for the inappropriate clinical use of antimicrobial agents and the control and prevention of enterococcal infections. Methods: a total of 1,157 enterococcal strains isolated from various clinical specimens from January 2010 to December 2012 in the General Hospital of Ningxia Medical University were identified to species level with a VITEK-2 COMPACT fully automated microbiological system, and the antimicrobial susceptibility of Enterococcus species was determined using the Kirby-Bauer disc diffusion method. The multiple-drug resistant enterococcal isolates were screened from the clinical isolates of Enterococcus species from the burns department. The minimal inhibitory concentration (MIC of Enterococcus species to the three fluoroquinolones, including ciprofloxacin, gatifloxacin and levofloxacin was determined with the agar dilution method, and the changes in the MIC of Enterococcus species to the three fluoroquinolones following reserpine treatment were evaluated. The β-lactam, aminoglycoside, tetracycline, macrolide, glycopeptide resistance genes and the efflux pump emeA genes were detected in the enterococcal isolates using a polymerase chain reaction (PCR assay. Results: the 1,157 clinical isolates of Enterococcus species included 679 E. faecium isolates (58.7%, 382 E. faecalis isolates (33%, 26 E. casseliflavus isolates (2.2%, 24 E. avium isolates (2.1%, and 46 isolates of other Enterococcus species (4%. The prevalence of antimicrobial resistance varied significantly between E. faecium and E. faecalis, and ≤1.1% of these two Enterococcus species were found to be resistant to vancomycin, teicoplanin or linezolid. In addition, the Enterococcus species isolated from different departments of the hospital

Risk of vancomycin-resistant enterococci bloodstream infection among patients colonized with vancomycin-resistant enterococci

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Ahu Kara

2015-01-01

Conclusion: In conclusion, our study found that 1.55% of vancomycin-resistant enterococci-colonized children had developed vancomycin-resistant enterococci bloodstream infection among the pediatric intensive care unit and hematology/oncology patients; according to our findings, we suggest that immunosupression is the key point for developing vancomycin-resistant enterococci bloodstream infections.

Antimicrobial susceptibility and glycopeptide-resistance of enterococci in vegetables

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Ida Torre

2010-03-01

Full Text Available

Background: Vancomycin-resistant enterococci (VRE, often responsible for nosocomial infections, have frequently been isolated from animal and vegetable foods. In our study we evaluated the antibiotic susceptibility of enterococci isolated from eight types of vegetables randomly selected from grocery stores in Naples.

Methods: From July to November 2008, we analyzed 150 samples: the bacteria were isolated with standardized methods and antibiotic susceptibility was determined using the disc diffusion method. The resistance to vancomycin versus other antibiotics was assessed by the Kappa test.

Results: 70% of the samples, mainly parsley (96.2%, showed enterococci. Of these, 59.1% belonged to the species Enterococcus faecium. Strains resistant to vancomycin and teicoplanin were isolated respectively in 47.6% and 49.5% of the samples: the first one mainly in curly endive (72.7% and the second one in parsley (76.9%. Almost all the isolated strains showed resistance to methicillin (89%, kanamycin (82% and cephalothin (68%. The Kappa test showed statistically significant associations between resistance to vancomycin and resistance to teicoplanin, erythromycin, methicillin, tetracycline and chloramphenicol.

Conclusions: Because of the possible involvement of food in the transmission of resistant micro-organisms to human intestinal microbiota, our data may provide the basis for future studies.

Antibiotic resistance in animals.

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Barton, Mary D; Pratt, Rachael; Hart, Wendy S

2003-01-01

There is currently no systematic surveillance or monitoring of antibiotic resistance in Australian animals. Registration of antibiotics for use in animals is tightly controlled and has been very conservative. Fluoroquinolones have not been registered for use in food producing animals and other products have been removed from the market because of human health concerns. In the late 1970s, the Animal Health Committee coordinated a survey of resistance in Salmonella and Escherichia coli isolates from cattle, pigs and poultry and in bovine Staphylococcus aureus. Some additional information is available from published case reports. In samples collected prior to the withdrawal of avoparcin from the market, no vancomycin resistant Enterococcus faecium or Enterococcus faecalis were detected in samples collected from pigs, whereas some vanA enterococci, including E. faecium and E. faecalis, were found in chickens. No vanB enterococci were detected in either species. Virginiamycin resistance was common in both pig and poultry isolates. Multiple resistance was common in E. coli and salmonellae isolates. No fluoroquinolone resistance was found in salmonellae, E. coli or Campylobacter. Beta-lactamase production is common in isolates from bovine mastitis, but no methicillin resistance has been detected. However, methicillin resistance has been reported in canine isolates of Staphylococcus intermedius and extended spectrum beta-lactamase producing E. coli has been found in dogs.

Antimicrobial resistance of Enterococcus isolates in Turkey: A meta-analysis of current studies.

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Kilbas, Imdat; Ciftci, Ihsan Hakki

2018-03-01

In this study, a meta-analysis of Enterococcus isolates collected in 2000-2015 in Turkey and their susceptibility/resistance to antibiotics, clinical indications for initial drug treatment, and identification of alternative treatments was conducted. The meta-analysis examined antibiotic susceptibility/resistance in Enterococcus spp. isolates. The study was planned and conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Statements on antimicrobial resistance were grouped according to the antimicrobial stewardship programme (ASP). The mean resistance rates of Enterococcus faecalis to vancomycin (VAN) and linezolid (LNZ) were 1.0±2.2% and 1.9±2.6%, respectively, whereas the mean resistance rates of Enterococcus faecium to VAN and LNZ were 10.3±11.3% and 2.4±0%, respectively. This study is the first meta-analysis of the resistance of clinical Enterococcus isolates in Turkey to antimicrobial agents, which is a major problem stemming from the excessive usage of antibiotics. The development of antibiotic resistance in Turkey has changed over time. To support the practice of evidence-based medicine, more notifications about Enterococcus resistance status are needed, especially notifications following ASP rules. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Vancomycin-resistant Staphylococcus aureus (VRSA) in hepatic cirrhosis patient: a case report

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Ramazoni, M.; Siregar, M. L.; Jamil, K. F.

2018-03-01

The irrational use of vancomycin in methicillin-resistant Staphylococcus aureus (MRSA) infections result in the emergence of vancomycin-resistant Staphylococcus aureus (VRSA) pathogen, which can pose a threat to the world healthcare. A 32-year-old male with hepatic cirrhosis patient admitted with recurrent gastrointestinal bleeding with a wound in his left leg since 6 months ago; the result microbiological culture showed a VRSA with minimum inhibitory concentration (MIC) vancomycin ≥32μg/mL The patient was treated with trimethoprim/sulfamethoxazole combination according to cultural sensitivity. The second microbiological culture showed thesame result. VRSA is a rare and difficult condition to handle. The success of therapy for this VRSA case warn us how important to cut the S. aureus distribution chain with a high level of resistance.

[Vancomycin-resistant enterococci - the nature of resistance and risk of transmission from animals to humans].

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Hermanovská, Lýdia; Bardoň, Jan; Čermák, Pavel

2016-06-01

Enterococci are part of the normal intestinal flora of humans and animals. Under certain circumstances, they are capable of extraintestinal conversion to opportunistic pathogens. They cause endogenous as well as exogenous community and nosocomial infections. The gastrointestinal tract of mammals provides them with favorable conditions for acquisition and spread of resistance genes, for example to vancomycin (van), from other symbiotic bacteria. Thus, vancomycin-resistant enterococci (VRE) become potential reservoirs and vectors of the van genes. Their occurrence in the population of the Czech Republic was first reported by Kolář et al. in 1997. Some variants of the vanA gene cluster carried on Tn1546 which encode resistance to vancomycin are identical in humans and in animals. It means that animals, especially cattle, poultry and pigs, could be an important reservoir of VRE for humans. Kolář and Bardoň detected VRE in animals in the Czech Republic for the first time in 2000. In Europe, the glycopeptide antibiotic avoparcin, used as a growth stimulator, is responsible for selection of VRE strains in animals. Strains of Enterococcus faecium from animals may offer genes of antimicrobial resistance to other enterococci or they can be directly dangerous to human. This is demonstrated by finding isolates of E. faecalis from human patients and from pigs having very similar profiles of resistance and virulence genes. The goal of the paper was to point out the similarity between isolates of human and animal strains of enterococci resistant to vancomycin, and the possibility of their bilateral transfer between humans and animals.

An optimal method for generating stable vancomycin heteroresistance and intermediate susceptibility in methicillin-resistant Staphylococcus aureusblood isolates under in-vitro vancomycin pressure

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Riad Khatib

2012-12-01

Full Text Available Objectives: The relevance of vancomycin intermediately-susceptible (VISA and hetero-resistant (hVISA methicillin-resistantStaphylococcus aureus (MRSA remains uncertain because of their low frequency. In vitro attempts to generate reducedsusceptibility have been inconsistent. We describe a simple method for generating VISA/hVISA.Materials and methods: Twenty-four SCCmec type II and IV MRSA blood isolates plus USA100 and USA300 controls werecultured (107 CFU/ml in BHI broth with 0, 2 and 3 mg/L vancomycin for 10 days followed by 10 days vancomycin-freepassage.We monitored vancomycin minimum inhibitory concentration (MIC; Etest and population analysis profile-areaunder the curve (PAP-AUC ratios of tested isolate-Mu3 during and after vancomycin pressure (VP. PAP-AUC ratios 1.3 were considered consistent with susceptible, hVISA and VISA, respectively.Results: VP at 2 mg/L (VP-2 increased MIC to 3 mg/L in 20 (83.3% isolates and raised PAP-AUC ratio to hVISA (n=18; 75.0%and VISA (six; 25.0% ranges. VP-3 increased MIC to 3 and 4 mg/L in 19 (79.2% and three (12.5% isolates, respectively andraised PAP-AUC ratio to hVISA (n=3; 12.5% and VISA (n=19; 79.2% ranges. SCCmec IV isolates had lower pre-exposurePAP-AUC ratios (0.48±0.14 vs. 0.69±0.10; p<0.001 and lower MIC (1.6±0.2 vs. 1.8±0.2 mg/L; p=0.1 but MIC rise and VISA/hVISA emergence was comparable. MIC and PAP-AUC ratio rises were stable in 20/22 isolates during drug-free passages.Conclusions: VISA/hVISA readily emerges among MRSA SCCmec type II and IV isolates under VP. VP at the MIC level generateshVISA while pressure at slightly higher level results in the VISA phenotype. J Microbiol Infect Dis 2012; 2(4: 129-134Key words: Staphylococcus aureus; heteroresistance; glycopeptides; resistance; bacteremia.

Evaluation of vancomycin MIC creep in methicillin-resistant Staphylococcus aureus infections-a systematic review and meta-analysis.

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Diaz, R; Afreixo, V; Ramalheira, E; Rodrigues, C; Gago, B

2018-02-01

Vancomycin is currently the primary option treatment for methicillin-resistant Staphylococcus aureus (MRSA). However, an increasing number of MRSA isolates with high MICs, within the susceptible range (vancomycin MIC creep), are being reported worldwide. Resorting to a meta-analysis approach, this study aims to assess the evidence of vancomycin MIC creep. We searched for studies in the PubMed database. The inclusion criteria for study eligibility included the possibility of retrieving the reported data values of vancomycin MIC and information concerning the applied MIC methodology. The mean values of vancomycin MICs, of all 29 234 S. aureus isolates reported in the 55 studies included in the meta-analysis, were 1.23 mg/L (95% CI 1.13-1.33) and 1.20 mg/L (95% CI 1.13-1.28) determined by Etest and broth microdilution method, respectively. No significant differences were observed between these two methodologies. We found negative correlation between pooled mean/pooled proportion and time strata. We have found no evidence of the MIC creep phenomenon. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Healthcare-associated vancomycin resistant Enterococcus faecium infections in the Mansoura University Hospitals intensive care units, Egypt

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Dalia Moemen

2015-09-01

Full Text Available Vancomycin resistant Enterococcus faecium (VREF ia an emerging and challenging nosocomial pathogen. This study aimed to determine the prevalence, risk factors and clonal relationships between different VREF isolates in the intensive care units (ICUs of the university hospitals in our geographic location. This prospective study was conducted from July, 2012 until September, 2013 on 781 patients who were admitted to the ICUs of the Mansoura University Hospitals (MUHs, and fulfilled the healthcare-associated infection (HAI criteria. Susceptibility testing was determined using the disk diffusion method. The clonal relationships were evaluated with pulsed field gel electrophoresis (PFGE. Out of 52 E. faecium isolates, 12 (23.1% were vancomycin resistant. The significant risk factors for the VREF infections were: transfer to the ICU from a ward, renal failure, an extended ICU stay and use of third-generation cephalosporins, gentamicin, or ciprofloxacin. PFGE with the 12 isolates showed 9 different patterns; 3 belonged to the same pulsotype and another 2 carried a second pulsotypes. The similar pulsotypes isolates were isolated from ICUs of one hospital (EICUs; however, all of the isolates from the other ICUs had different patterns. Infection control policy, in conjunction with antibiotic stewardship, is important to combat VREF transmission in these high-risk patients.

Prevalence and antibiotic resistance of Enterococcus strains isolated from poultry.

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Stępień-Pyśniak, Dagmara; Marek, Agnieszka; Banach, Tomasz; Adaszek, Łukasz; Pyzik, Ewelina; Wilczyński, Jarosław; Winiarczyk, Stanisław

2016-06-01

The aim of this study was to evaluate the frequency of occurrence of bacteria of the genus Enterococcus in poultry, to identify them by means of matrixassisted laser desorption/ionisation time-of-flight mass spectrometry (MALDITOF MS), and to analyse the antimicrobial susceptibility of the isolated strains to the drugs most frequently used in poultry. The material for the bacteriological tests was obtained mainly from the heart (97%) of the birds investigated. Of a total of 2,970 samples tested, 911 (30.7%) tested positive for Enterococcus spp. Enterococci were detected in broilers (88.1%), laying hens (5.3%), turkeys (3.9%), breeding hens (2.2%), and geese (0.4%). The most commonly identified species were Enterococcus (E.) faecalis (74.7%), E. faecium (10.1%), E. gallinarum (5.5%), E. hirae (4.6%), and E. cecorum (4.1%). The most frequent resistance properties were resistance to sulphamethoxazole/trimethoprim (88%), tylosin (71.4%), enrofloxacin (69.4%), doxycycline (67.3%), and lincomycin/spectinomycin (56.1%). Only one vancomycin-resistant Enterococcus, E. cecorum from a broiler, was found.

An Investigation of Antibiotic Resistance Pattern in the Strains of Methicillin-resistant Staphylococcus epidermidis Isolated From Clinical Samples in Isfahan Province, Iran

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Fahimeh Nourbakhsh

2016-08-01

Full Text Available Background and Objectives: Staphylococcus epidermidis is one of the effective factors causing nosocomial infections. This study was performed to investigate the antibiotic resistance pattern in the methicillin-resistant S. epidermidis strains isolated from clinical samples in Isfahan Province. Methods: In this descriptive cross-sectional study, 150 isolates of S. epidermidis were isolated from detected from the patients hospitalized in hospitals and treatment centers of Isfahan City. The antibiotic resistance pattern was evaluated by disk diffusion method. The presence of the gene encoding antibiotic resistance to methicillin (mec A in the isolates were investigated using PCR method. Data were analyzed with Chi-square and Fisher's exact statistical tests. Results: In this study, most isolates were related to urinary tract infections. The highest resistance was reported to penicillin (98.9%, erythromycin (89.4%, ciprofloxacin (77.7%, clindamycin (65.9%, tetracycline (63.2%, and meticillin (54%. None of the strains showed resistance to vancomycin and linezolid. Molecular studies indicated the presence of mecA gene in 76% of the studied isolates. Conclusion: According to the results of this study, vancomycin and linezolid antibiotics can be the best choice of treatment for infections caused by S. epidermidis. Also, high resistance of S. epidermidis can be a serious warning for increased multiple antibiotic resistance. Molecular studies are indicative of high sensitivity of molecular methods in the investigation of methicillin-resistant isolates.  

Antibiotic resistant pattern of methicillin resistant and sensitive Staphylococcus aureus isolated from patients durining 2009-2010, Ahvaz, Iran.

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N Parhizgari

2013-12-01

Full Text Available Abstract Background & aim: Staphylococcus aureus is one of the most important nosocomial infecting agents resistant to commonly used antibiotics. Nowadays, methicillin-resistant S. aureus (MRSA is considered one of the main causes of nosocomial infections. The aim of this study was to identify the antibiotic resistance pattern of methicicllin- resistant and susceptible strains in Ahwaz, Iran. Methods: In the present cross - sectional study, a number of 255 clinically suspected cases of Staphylococcus aureus were collected during a 19 month period. The bacteria were investigated using standard biochemical tests such as catalase, mannitol fermentation, coagulase and Dnase. Sensitive strains were confirmed by disk diffusion method compared to commonly used antibiotics. The collected data were analyzed using descriptive statistical tests. Results: of 255 suspected cases, 180 were confirmed as S.aureus, a total of 59 strains of S. aureus (2/37 percent were resistant to methicillin. Resistance to S. aureus strains resistant to methicillin included: chloramphenicol (3.38%, rifampin (45.76%, norfloxacin (89.83%, gentamicin (89.83%, ciprofloxacin, (91.52%, azithromycin, (88.13%, cotrimoxazole (86.44% and all isolates strains were sensitive to vancomycin and nitrofurantoin. A total of 10 different patterns of antibiotic resistance in methicillin-resistant Staphylococcus aureus strains were identified. Conclusion: Expression of new resistance factor in nosocomial infection is one of the major challenges in treating these infections. This study showed a high prevalence of resistance against some class of antibiotics in MRSA isolated from Imam Khomeini and Golestan hospital of Ahwaz, Iran. Key words: Nosocomial infection, Methicillin Resistant Staphylococcus aureus (MRSA, Antibiotic Resistant Pattern

Glycopeptide resistance in Enterococcus faecium from broilers and pigs following discontinued use of avoparcin

DEFF Research Database (Denmark)

Bager, Flemming; Aarestrup, Frank Møller; Madsen, Mogens

1999-01-01

The use of the glycopeptide growth promoter avoparcin was discontinued in Denmark in 1995 following concerns that vancomycin-resistant Enterococcus faecium occurring as a result of its use could be transferred to humans via food. The present study is an analysis of results obtained by the continu......The use of the glycopeptide growth promoter avoparcin was discontinued in Denmark in 1995 following concerns that vancomycin-resistant Enterococcus faecium occurring as a result of its use could be transferred to humans via food. The present study is an analysis of results obtained...... by the continuous surveillance of an antimicrobial resistance in Denmark (DANMAP) with the aim of determining the effect of the ban on the occurrence of glycopeptide resistance among E, faecium isolated from broilers and pigs, Among isolates from broilers, the proportion that were resistant to glycopeptides has....... Alternatively, the results indicate that the different outcomes may result from different co-selection patterns in pigs and broilers. In pigs, the antimicrobials most commonly used favored co-selection of glycopeptide-resistant strains of E. faecium while in broilers the antimicrobials most widely used selected...

Resistance to Antibiotics in Strains of Staphylococcus spp., Enterococcus spp. and Escherichia coli Isolated from Rectal Swabs of Pigs

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M. Kolář

2008-01-01

Full Text Available The study aimed at determining the level of resistance of selected bacterial species (Staphylococcus spp., Enterococcus spp., Escherichia coli isolated from rectal swabs of pigs to antimicrobial agents. The tested strains were isolated from piglets aged 7 to 30 days. Bacterial species were identified by standard microbiological techniques and susceptibility to antibiotics was determined quantitatively by the standard microdilution method. Resistance of the Staphylococcus aureus strain to oxacillin was confirmed by detection of the mecA gene and PBP2a. A total of 115 Staphylococcus spp. isolates were collected. In the case of Staphylococcus aureus, the methicillin-resistant strain (MRSA was identified. Moreover, higher frequency of coagulase-negative staphylococci with minimum inhibitory concentration of oxacillin ≥ 0.5 mg/l was noticed. Inducible resistance to clindamycin in the Staphylococcus hominis strain was also detected. The strains of Enterococcus spp. (61 isolates exhibited high resistance to tetracycline (98.5%, erythromycin (86.8% and chloramphenicol (54.4%. Vancomycin-resistant enterococci were not isolated. In the case of Escherichia coli strains (111 isolates, higher frequency of resistant strains to tetracycline (81.1% and ampicillin (62.2% was documented. Resistance to fluoroquinolones and production of broad-spectrum β-lactamases was not noticed. The presented study may be considered as a pilot project assessing the prevalence of resistant bacteria in piglets kept on a single farm. It demonstrated the presence of resistant strains of Staphylococcus spp., including one MRSA strain, Enterococcus spp. and Escherichia coli. These strains may be present as a result of postnatal colonization with both bacterial microflora of dams and environmental microflora.

Role of the transmembrane domain of the VanT serine racemase in resistance to vancomycin in Enterococcus gallinarum BM4174.

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Arias, C A; Peña, J; Panesso, D; Reynolds, P

2003-03-01

Enterococcus gallinarum BM4175 (a vancomycin-susceptible derivative of BM4174 obtained by insertional inactivation of vanC-1) was transformed with plasmid constructs pCA10 (containing the genes necessary for resistance, vanC-1-XYc-T), pJP1 (with a fragment lacking the DNA encoding the transmembrane region of VanT, -vanC-1-XYc-T((Delta))(2-322)-) and with plasmids containing fragments encoding either the transmembrane (mvanT(1-322)) or racemase (svanT(323-698)) domains of VanT under the control of a constitutive promoter. Accumulated peptidoglycan precursors were measured in all strains in the presence of L-Ser, D-Ser (50 mM) or in the absence of any growth supplement. Uptake of 0.1 mM L-[(14)C]serine was also determined in BM4174, BM4175 and BM4175/pCA10. Vancomycin resistance was restored in BM4175 transformed with pCA10(C-1-XYc-T), and the profile of peptidoglycan precursors was similar to wild-type E. gallinarum BM4174. Transformation of E. gallinarum BM4175 with plasmid pJP1(vanC-1-XYc-T((Delta))(2-322)) resulted in: (i) vancomycin MICs remaining within susceptible levels (VanT is likely to be involved in the transport of L-Ser, and that in its absence the resistance phenotype is compromised.

Vancomycin resistant Enterococcus spp. from crows and their environment in metropolitan Washington State, USA: Is there a correlation between VRE positive crows and the environment?

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Roberts, Marilyn C; No, David B; Marzluff, John M; Delap, Jack H; Turner, Robert

2016-10-15

Vancomycin-resistant enterococci [VRE] have been isolated from municipal, hospital and agricultural wastewater, recreational beaches, wild animals, birds and food animals around the world. In this study, American crows (Corvus brachyrhynchos) from sewage treatment plants (WWTP), dairy farms, and a large roost in a restored wetland with corresponding environmental samples were cultured for VRE. A total of 245 samples [156 crows, 89 environmental] were collected and screened for acquired vanA, vanB and/or intrinsic vanC1 genes. Samples were enriched overnight in BHI supplemented with 20μg/mL aztreonam, 4μg/mL vancomycin and plated on m-Enterococcus agar media supplemented with 6μg/mL vancomycin. Selected colonies were grown on BHI media supplemented with 18μg/mL vancomycin. Of these, 24.5% of the crow and 55% the environmental/cow samples were VRE positive as defined by Enterococcus spp. able to grow on media supplemented with 18μg/mL vancomycin. A total of 122 VRE isolates, 43 crow and 79 environmental isolates were screened, identified to species level using 16S sequencing and further characterized. Four vanA E. faecium and multiple vanC1 E. gallinarum were identified from crows isolated from three sites. E. faecium vanA and E. gallinarum vanC1 along with other Enterococcus spp. carrying vanA, vanB, vanC1 were isolated from three environments. All enterococci were multidrug resistant. Crows were more likely to carry vanA E. faecium than either the cow feces or wetland waters/soils. Comparing E. gallinarum vanC1 from crows and their environment would be useful in determining whether crows share VRE strains with their environment. Copyright © 2016 Elsevier B.V. All rights reserved.

Cost Comparison of Linezolid Versus Vancomycin for Treatment of Complicated Skin and Skin-Structure Infection Caused by Methicillin-Resistant Staphylococcus aureus in Quebec

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Martine Pettigrew

2012-01-01

Full Text Available BACKGROUND: In Canada, complicated skin and skin-structure infection (cSSSI caused by methicillin-resistant Staphylococcus aureus (MRSA is usually treated with antibiotics in hospital, with a follow-up course at home for stable patients. The cost implications of using intravenous and oral linezolid instead of intravenous vancomycin in Canadian clinical practice have not been examined.

Our experiences with vancomycin-resistant enterococci in Jesenice General hospital

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Helena Ribič

2007-11-01

Full Text Available Background: Vancomycin-resistant enterococci (VRE present a great problem in health care, especially because of their resistance to many groups of antibiotics and because of the way of their spreading in health care and long-term care institutions. Genes responsible for resistance to vancomycin can be transmitted to other species of enterococci and also to other grampositive cocci, for example Staphylococcus aureus. Experts anticipate that failure to control methicilin-resistant S. aureus and VRE may make control of vancomycin-resistant S. aureus impossible.Methods: In the medical microbiology laboratory of Institute Public Health Kranj we perform microbiology diagnosis for Jesenice General Hospital, where surveillance culturing for VRE started in May 2007. Until 15th June, 364 surveillance samples for VRE were taken from 92 patients. We also analysed the results of enterococci that were isolated in our laboratory during routine work in the period from 2004 to 2006.Results: In the three-year period we isolated 1593 strains of enterococci and among them 7 strains were VRE. In the Jesenice General Hospital, the first strain of vancomycin-resistant Enterococcus faecium was isolated in May 2007 in a patient, treated in internal intensive care unit. Nine strains of VRE with the same resistance type in nine patients followed the first case. The first four patients with VRE were moved from the same hospital. Among next six patients the common risk factor was contact with VRE positive patient.Conclusions: Control of VRE strains claims for intensive action. Active surveillance of colonised and infected patients, contact precautions with barrier isolation, intensive hand hygiene measures, aggressive environmental decontamination and prudent use of antimicrobials are needed.

Vancomycin-resistant Enterococcus spp.: validation of susceptibility testing and in vitro activity of vancomycin, linezolid, tigecycline and daptomycin

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Rathe, Mathias; Kristensen, Lise; Ellermann-Eriksen, Svend

2010-01-01

Vancomycin-resistant enterococci (VRE) have emerged to become a significant nosocomial pathogen. However, detection may be challenging and treatment possibilities are limited. Reports of resistance to linezolide, daptomycin and tigecycline underline the need for reliable susceptibility testing wi...

Antibiotic susceptibility pattern of staphylococcus aureus and methicillin-resistant staphylococcus aureus in a tertiary care hospital

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CP Bhatt

2014-04-01

Full Text Available Background: Methicillin resistant Staphylococcus aureushas emerged as one of the most important nosocomial pathogens. It invokes a tremendous financial burden and enhanced morbidity and mortality due to difficult to treat systemic infections.Aim of this study was to determine antibiotic susceptibility pattern of Staphylococcus aureus and Methicillin resistant Staphylococcus aureus. Materials and Methods: Different clinical specimens were collected and processed for routine culture and antibiotic sensitivity test by standard microbiology techniques. Results: Out of 1173 samples received for microbiological examination, 100 were found to be S. aureus with 19% cases were Methicillin resistant Staphylococcus aureus (MRSA. Fourteen MRSA were found from inpatient and 5 were from outpatient. MRSA was found higher in female than male and maximum number (31.5% was found in age group 0-10 years. Staphylococcus aureus was 100% sensitive to Vancomycin followed by Amikacin (90%, Gentamycin (83%, and tetracycline (81%. On urine isolates Nitrofurantoin(91.6% was drug of choice. All the isolates were resistant to Penicillin G. In case of Methicillin resistant Staphylococcus aureus showed 100% sensitive to Vancomycin followed by Amikacin (84.2%, Tetracycline (63.1%, Ciprofloxacin (42% and Gentamycin (36.8%. Among urine isolates Nitrofutantoin showed 87.5% sensitive followed by Norfloxacin (75%. Conclusion: Methicillin resistant Staphylococcus aureus was found 19% of Staphylococcus aureus isolates. It was most common in females, hospitalized patients and young age group. Vancomycin seems to be drug of choice followed by Amikacin. It would be helpful to formulating and monitoring the antibiotic policy and ensure proper empiric treatment. DOI: http://dx.doi.org/10.3126/jpn.v4i7.10297 Journal of Pathology of Nepal (2014 Vol. 4, 548-551   

Methicillin-resistant coagulase-negative staphylococci from healthy dogs in Nsukka, Nigeria

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Kennedy F. Chah

2014-01-01

Full Text Available The occurrence, resistance phenotype and molecular mechanisms of resistance of methicillin-resistant staphylococci from groin swabs of 109 clinically healthy dogs in Nsukka, Nigeria were investigated. The groin swab samples were cultured on mannitol salt agar supplemented with 10 µgof cloxacillin. Sixteen methicillin-resistant coagulase negative staphylococci (MRCoNS, all harbouring the mecA gene were isolated from 14 (12.8% of the 109 dogs studied. The MRCoNS isolated were: S. sciuri subspecies rodentium, S. lentus, S. haemolyticus, and S. simulans with S. sciuri subspecies rodentium (62.5% being the predominant species. Thirteen (81.3% of the MRCoNS were resistant to tetracycline while 12 (75% and 10 (62.5% were resistant to kanamycin and trimthoprim-sulphamethoxazole respectively. None of the isolates was resistant to fusidic acid, linezolid and vancomycin. Thirteen (81.3% of the MRCoNS were multi-drug resistance (MDR. Other antimicrobial genes detected were: blaZ, tet(K, tet(M, tet(L, erm(B, lnu(A, aacA-aphD, aphA3, str, dfr(G, cat pC221,and cat pC223. Methicillin-resistant staphylococci are common colonizers of healthy dogs in Nigeria with a major species detected being S. sciuri subsp. rodentium.

Rapid Emergence of Resistance to Linezolid during Linezolid Therapy of an Enterococcus faecium Infection▿

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Seedat, Jamela; Zick, Günther; Klare, Ingo; Konstabel, Carola; Weiler, Norbert; Sahly, Hany

2006-01-01

We report the emergence of linezolid resistance (MICs of 16 to 32 mg/liter) in clonally related vancomycin-susceptible and -resistant Enterococcus faecium isolates from an intensive care unit patient after 12 days of linezolid therapy. Only linezolid-susceptible isolates of the same clone were detected at 28 days after termination of linezolid therapy.

Transposon characterization of vancomycin-resistant Enterococcus faecium (VREF) and dissemination of resistance associated with transferable plasmids

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Migura, Lourdes Garcia; Liebana, Ernesto; Jensen, Lars Bogø

2007-01-01

Objectives: VanA glycopeptide resistance has persisted on broiler farms in the UK despite the absence of the antimicrobial selective pressure, avoparcin. This study aimed to investigate the contribution of horizontal gene transfer of Tn 1546 versus clonal spread in the dissemination of the resist......Objectives: VanA glycopeptide resistance has persisted on broiler farms in the UK despite the absence of the antimicrobial selective pressure, avoparcin. This study aimed to investigate the contribution of horizontal gene transfer of Tn 1546 versus clonal spread in the dissemination...... plasmid replicons, associated with antimicrobial resistance on several unrelated farms. Conclusions: Horizontal transfer of vancomycin resistance may play a more important role in the persistence of antimicrobial resistance than clonal spread. The presence of different plasmid replicons, associated...... with antimicrobial resistance on several unrelated farms, illustrates the ability of these enterococci to acquire and disseminate mobile genetic elements within integrated livestock systems....

Phenotypic changes of methicillin-resistant Staphylococcus aureus during vancomycin therapy for persistent bacteraemia and related clinical outcome.

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Kim, T; Kim, E S; Park, S Y; Sung, H; Kim, M-N; Kim, S-H; Lee, S-O; Choi, S-H; Jeong, J-Y; Woo, J H; Chong, Y P; Kim, Y S

2017-08-01

Persistent bacteraemia (PB) due to methicillin-resistant Staphylococcus aureus (MRSA) that fails to respond to glycopeptide therapy is a well-documented clinical problem. There are limited data on changes in agr functionality, vancomycin susceptibility and heteroresistance during MRSA PB. Thus, the frequency of these changes and their clinical significance remain unclear. Only patients with MRSA PB (≥7 days) from a prospective cohort of S. aureus bacteraemia were included. We collected isogenic paired strains and compared vancomycin MIC, vancomycin heteroresistance, and agr functionality between initial and final blood isolates. We also assessed the clinical outcome. A total of 49 patients had MRSA PB over 22 months. Bacteraemia persisted for a median of 13 days and most patients (98%) received glycopeptide as initial therapy. Among 49 isogenic pairs, only one pair showed a vancomycin MIC increase ≥2-fold by broth microdilution method, and only seven (14%) by E-test. Significant portions of initial isolates had vancomycin heteroresistance (49%) and agr dysfunction (76%). Development of vancomycin heteroresistance during PB occurred in four (16%) among 25 initial vancomycin-susceptible isolates, and acquisition of agr dysfunction occurred in two (16%) among 12 initial agr-functional isolates. Changes in the opposite direction occasionally occurred. These phenotypic changes during PB were not associated with mortality, whereas agr dysfunction of the initial isolates was significantly associated with mortality. During MRSA PB, phenotypic changes of MRSA isolates occurred occasionally under prolonged vancomycin exposure but were not significantly associated with clinical outcome. In contrast, initial agr dysfunction could be a predictor for mortality in MRSA PB.

The frequency of resistance to antibiotics of most frequently isolated bacteria from blood cultures during the period 1997-2002

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Mirović Veljko

2004-01-01

Full Text Available The aim of this study was to determine the frequency of resistance to antibiotics of the most frequently isolated bacteria from blood cultures of hospitalized patients during the period 1997-2002. The resistance to antibiotics was determined by disk diffusion method according to National Committee for Clinical Laboratory Standards procedures. The majority of staphylococci isolates were resistant to methicillin, and the proportion of methicillin-resistant Staphylococcus aureus was stable (76.8-81.6%, during the follow-up period. None of the staphylococci isolates were resistant to vancomycin, but there was a very high incidence of high-level resistance of enterococci to aminoglycosides (47.2-72.2%. In 1998, only one strain among enterococci was resistant to vancomycin (Enterococcus faecium, VanA fenotype. Enterococcus spp isolates expressed variable frequency of resistance to ampicillin (15-40.1% during the follow-up period. Among Enterobacteriaceae there were no isolates resistant to imipenem, but dramatic increase of the resistance to ceftriaxone was found from 35.9% in 1997 to 95.9% in 2002 (p<0.001. Extended spectrum beta-lactamases production was found in all the species of enterobacteria isolates. Resistance to imipenem was observed in Acinetobacter spp isolates in 2002 for the first time. Pseudomonas spp isolates expressed high and very variable resistance to all antibiotics tested during the follow-up period.

Stimulated phase-shift acoustic nanodroplets enhance vancomycin efficacy against methicillin-resistant Staphylococcus aureus biofilms

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Guo H

2017-06-01

Full Text Available Hao Guo,1 Ziming Wang,1 Quanyin Du,1 Pan Li,2 Zhigang Wang,2 Aimin Wang1 1Department of Orthopedics, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, China; 2Chongqing Key Laboratory of Ultrasound Molecular Imaging, Institute of Ultrasound Imaging, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China Purpose: Bacterial biofilms on the surface of prostheses are becoming a rising concern in managing prosthetic joint infections. The inherent resistant features of biofilms render traditional antimicrobial therapy unproductive and revision surgery outcomes uncertain. This situation has prompted the exploration of novel antimicrobial strategies. The synergy of ultrasound microbubbles and vancomycin has been proposed as an efficient alternative for biofilm eradication. The purpose of this study was to evaluate the anti-biofilm effect of stimulated phase-shift acoustic nanodroplets (NDs combined with vancomycin.Materials and methods: We fabricated lipid phase-shift NDs with a core of liquid perfluoropentane. A new phase change mode for NDs incorporating an initial unfocused low-intensity pulsed ultrasound for 5 minutes and a subsequent incubation at 37°C into a 24-hour duration was developed. Methicillin-resistant Staphylococcus aureus (MRSA biofilms were incubated with vancomycin and NDs under the hybrid stimulation. Biofilm morphology following treatment was determined using confocal laser scanning microscopy and scanning electron microscopy. Resazurin assay was used to quantify bactericidal efficacy against MRSA biofilm bacteria.Results: NDs treated sequentially with ultrasound and heating at 37°C achieved gradual and substantial ND vaporization and cavitation in a successive process. NDs after stimulation were capable of generating stronger destruction on biofilm structure which was best characterized by residual circular arc margins and more dead bacteria. Furthermore, NDs

Derivatives of a vancomycin-resistant Staphylococcus aureus strain isolated at Hershey Medical Center.

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Bozdogan, Bülent; Ednie, Lois; Credito, Kim; Kosowska, Klaudia; Appelbaum, Peter C

2004-12-01

Antimicrobial susceptibilities and genetic relatedness of the vancomycin-resistant Staphylococcus aureus strain (VRSA) isolated at Hershey, Pa. (VRSA Hershey), and its vancomycin-susceptible and high-level-resistant derivatives were studied and compared to 32 methicillin-resistant S. aureus strains (MRSA) isolated from patients and medical staff in contact with the VRSA patient. Derivatives of VRSA were obtained by subculturing six VRSA colonies from the original culture with or without vancomycin. Ten days of drug-free subculture caused the loss of vanA in two vancomycin-susceptible derivatives for which vancomycin MICs were 1 to 4 microg/ml. Multistep selection of three VRSA clones with vancomycin for 10 days increased vancomycin MICs from 32 to 1,024 to 2,048 microg/ml. MICs of teicoplanin, dalbavancin, and oritavancin were also increased from 4, 0.5, and 0.12 to 64, 1, and 32 microg/ml, respectively. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing analysis indicated that VRSA Hershey was the vanA-acquired variety of a common MRSA clone in our hospital with sequence type 5 (ST5). Three of five vancomycin-intermediate S. aureus strains tested from geographically different areas were also ST5, and the Michigan VRSA was ST371, a one-allele variant of ST5. Derivatives of VRSA Hershey had differences in PFGE profiles and the size of SmaI fragment that carries the vanA gene cluster, indicating instability of this cluster in VRSA Hershey. However induction with vancomycin increased glycopeptide MICs and stabilized the resistance.

Influence of vancomycin minimum inhibitory concentration on the treatment of methicillin-resistant Staphylococcus aureus bacteremia.

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Soriano, Alex; Marco, Francesc; Martínez, José A; Pisos, Elena; Almela, Manel; Dimova, Veselka P; Alamo, Dolores; Ortega, Mar; Lopez, Josefina; Mensa, Josep

2008-01-15

Vancomycin treatment failure in methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is not uncommon, even when MRSA is susceptible to vancomycin. The aim of our study was to evaluate whether vancomycin minimum inhibitory concentration has any influence on the mortality associated with MRSA bacteremia. A total of 414 episodes of MRSA bacteremia were prospectively followed-up from 1991 through 2005. MIC of vancomycin for the first isolate was determined by E-test. Clinical variables recorded were age, comorbidity, prior administration of vancomycin, use of corticosteroids, prognosis of underlying disease, source of bacteremia, the need for mechanical ventilation, shock, and mortality. A "treatment group" variable was created and defined as follows: (1) receipt of empirical vancomycin and an isolate with a vancomycin MIC of 1 microg/mL (38 episodes), (2) receipt of empirical vancomycin and an isolate with a vancomycin MIC of 1.5 microg/mL (90 episodes), (3) receipt of empirical vancomycin and an isolate with a vancomycin MIC of 2 microg/mL (40 episodes), and (4) receipt of inappropriate empirical therapy (246 episodes). Univariate and multivariate analyses were performed. Episodes caused by strains with a vancomycin MIC of 2 microg/mL were independently associated with a lower risk of shock (odds ratio [OR], 0.33; 95% confidence interval [CI], 0.15-0.75). Multivariate analysis selected receipt of empirical vancomycin and an isolate with a vancomycin MIC of 2 microg/mL (OR, 6.39; 95% CI, 1.68-24.3), receipt of inappropriate empirical therapy (OR, 3.62; 95% CI, 1.20-10.9), increasing age (OR, 1.02; 95% CI, 1.00-1.04), use of corticosteroids (OR, 1.85; 95% CI, 1.04-3.29), an ultimately (OR, 10.2; 95% CI, 2.85-36.8) or rapidly (OR, 1.81; 95% CI, 1.06-3.10) fatal underlying disease, high-risk (OR, 3.60; 95% CI, 1.89-6.88) and intermediate-risk (OR, 2.18; 95% CI, 1.17-4.04) sources of bacteremia, and shock (OR, 7.38; 95% CI, 4.11-13.3) as the best predictors of

Inducible clindamycin and methicillin resistant Staphylococcus aureus in a tertiary care hospital, Kathmandu, Nepal.

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Adhikari, R P; Shrestha, S; Barakoti, A; Amatya, R

2017-07-11

Staphylococcus aureus, an important nosocomial pathogen, is frequently associated with infections in human. The management of the infections by it especially methicillin resistant ones is often difficult because methicillin resistant S. aureus is usually resistant to multiple antibiotics. Macrolide-lincosamide streptogramin B family of antibiotics is commonly used to treat such infections as an alternative to vancomycin. This study was conducted over the period of one and half year from November 2013-April 2015 in Microbiology laboratory of Nepal Medical College and Teaching Hospital, Kathmandu, Nepal to find the incidence of different phenotypes of MLS B resistance among S. aureus from clinical samples and their association with methicillin resistance. Two hundred seventy isolates of S. aureus were included in the study. Methicillin resistance was detected by cefoxitin disc diffusion method and inducible clindamycin resistance by erythromycin and clindamycin disc approximation test (D-test). Of the 270 clinical isolates of S. aureus, 25.1% (68/270) were MRSA. Erythromycin and clindamycin resistance was seen in 54.4% (147/270) and 41.8% (113/270) isolates respectively. Resistance to erythromycin and clindamycin were higher in MRSA as compared to MSSA (erythromycin-resistance: 88.2% Vs 39.1% and clindamycin-resistance: 79.4% Vs 41.8%). The overall prevalence of i MLS B and c MLS B phenotype was 11.48% (31/270) and 29.25% (79/270) respectively. Both i MLS B and c MLS B phenotypes predominated in MRSA strains. Detection rate of MRSA in our study shows the necessity to improve in healthcare practices and to formulate new policy for the control of MRSA infections. Clindamycin resistance in the form of i MLS B and c MLS B especially among MRSA emphasizes the need of D-test to be performed routinely in our set up while using clindamycin as an alternative choice to anti-staphylococcal antibiotics like vancomycin and linezolid in the treatment of staphylococcal infections.

Typing of vancomycin-resistant enterococci with MALDI-TOF mass spectrometry in a nosocomial outbreak setting

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Holzknecht, B J; Dargis, R; Pedersen, M

2018-01-01

OBJECTIVES: To investigate the usefulness of matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) typing as a first-line epidemiological tool in a nosocomial outbreak of vancomycin-resistant Enterococcus faecium (VREfm). METHODS: Fifty-five VREfm isolates...

Investigation of the potential for mutational resistance to XF-73, retapamulin, mupirocin, fusidic acid, daptomycin, and vancomycin in methicillin-resistant Staphylococcus aureus isolates during a 55-passage study.

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Farrell, David J; Robbins, Marion; Rhys-Williams, William; Love, William G

2011-03-01

XF-73 is a dicationic porphyrin drug with rapid Gram-positive antibacterial activity currently undergoing clinical trials for the nasal decolonization of Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus (MRSA). In multistep (55-passage) resistance selection studies in the presence of subinhibitory concentrations of XF-73, retapamulin, mupirocin, fusidic acid, and vancomycin against four Network on Antimicrobial Resistance in Staphylococcus aureus MRSA strains, there was no >4-fold increase in the MIC for XF-73 after 55 passages. In contrast, there was an increase in the MICs for retapamulin (from 0.25 μg/ml to 4 to 8 μg/ml), for mupirocin (from 0.12 μg/ml to 16 to 512 μg/ml), for fusidic acid (from 0.12 μg/ml to 256 μg/ml), and for vancomycin (from 1 μg/ml to 8 μg/ml in two of the four strains tested). Further investigations using S. aureus NRS384 (USA300) and daptomycin demonstrated a 64-fold increase in the MIC after 55 passages (from 0.5 μg/ml to 32 μg/ml) with a >4-fold increase in the MIC obtained after only five passages. Sequencing analysis of selected isolates confirmed previously reported point mutations associated with daptomycin resistance. No cross-resistance to XF-73 was observed with the daptomycin-resistant strains, suggesting that whereas the two drugs act on the bacterial cell membrane, their specific site of action differs. XF-73 thus represents the first in a new class of antibacterial drugs, which (unlike the comparator antibiotics) after 55 passages exhibited a ≤4-fold increase in MIC against the strains tested. Antibacterial drugs with a low propensity for inducing bacterial resistance are much needed for the prevention and treatment of multidrug-resistant bacteria both within and outside the hospital setting.

Marinopyrrole Derivatives as Potential Antibiotic Agents against Methicillin-Resistant Staphylococcus aureus (II

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Rongshi Li

2013-08-01

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA continues to be a major problem, causing severe and intractable infections worldwide. MRSA is resistant to all beta-lactam antibiotics, and alternative treatments are limited. A very limited number of new antibiotics have been discovered over the last half-century, novel agents for the treatment of MRSA infections are urgently needed. Marinopyrrole A was reported to show antibiotic activity against MRSA in 2008. After we reported the first total synthesis of (±-marinopyrrole A, we designed and synthesized a series of marinopyrrole derivatives. Our structure activity relationship (SAR studies of these novel derivatives against a panel of Gram-positive pathogens in antibacterial assays have revealed that a para-trifluoromethyl analog (33 of marinopyrrole A is ≥63-, 8-, and 4-fold more potent than vancomycin against methicillin-resistant Staphylococcus epidermidis (MRSE, methicillin-susceptible Staphylococcus aureus (MSSA and MRSA, respectively. The results provide valuable information in the search for new-generation antibiotics.

Persistence of vancomycin-resistant enterococci (VRE) in broiler houses after the avoparcin ban

DEFF Research Database (Denmark)

Heuer, Ole Eske; Pedersen, Karl; Jensen, Lars Bogø

2002-01-01

The glycopeptide growth promoter avoparcin was banned from animal production in the EU in 1997 due to concern for the spread of vancomycin-resistant enterococci (VRE) from food animals to humans. In recent Norwegian and Danish studies, extensive occurrence of VRE on broiler farms and in broiler......, and disinfection of the houses between rotations, and two consecutive broiler flocks from each house were sampled by taking cloacal swabs from the broilers at the time of slaughter. A total of 69 vancomycin-resistant Enterococcus faecium isolates obtained from broiler flocks and broiler houses were subjected......-isolates from different broiler houses and from flocks reared in different houses appeared to be genetically unrelated. These findings indicated that VRE was transmitted between consecutive broiler flocks by clones of resistant. bacteria surviving in the broiler houses despite cleaning and disinfection between...

Prevalence and Removal Efficiency of Enterococcal Species and Vancomycin-resistant Enterococci of a Hospital Wastewater Treatment Plant

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Fatemeh Karimi

2016-12-01

Full Text Available Simultaneous presence of various antibiotics and bacteria in hospital wastewaters creates a suitable environment, in which the bacteria, such as ‎enterococci become resistant to the antibiotics. The aim of this study was to evaluate the performance of different units of the hospital wastewater treatment plant (HWTP to remove Enterococcus spp and Vancomycin-resistant Enterococcus (VRE. The study was performed on the 27 samples collected from HWTP in Hamedan, Iran during December 2014 to August 2015. Enterococcus spp and VRE were identified by biochemical tests and then the isolates were confirmed by PCR. Finally, the antibiotic susceptibility test was performed using disk diffusion methods. Of the 27 samples examined, 315 a total of enterococcal isolates were obtained. Of the 315 isolates of enterococci investigated, 162 (51.42% were identified as E. faecium, 87 (27.61% as E. hirae, 35 (11.11% as E. faecalis, 11 (3.5% as E. gallinarum, 7 (2.22% as E. casseliflavus, 4 (1.26% E. avium, and 9 (2.85% isolates VR E. faecium.The results of antibiotic susceptibility testing showed that of the total 315 isolates, 146 (46.34% were resistance to tetracycline, 9 (2.85% were resistance to vancomycin and Teicoplanin. Lower antibiotic resistance was seen with Nitrofurantoin 2 (1.26%. This study indicates a high prevalence of multidrug resistance among E. faecium isolated from HWTP, thus, it could be considered as a threat to the health and safety of ‎wastewater workers and even public health.

Comparison of Linezolid and Vancomycin for Methicillin-Resistant Staphylococcus aureus Pneumonia: Institutional Implications.

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Tong, ManShan C; Wisniewski, Christopher S; Wolf, Bethany; Bosso, John A

2016-07-01

Recent studies suggesting clinical superiority of linezolid over vancomycin in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) pneumonia led to a change in our institution's clinical pathway/order form for hospital-acquired pneumonia, positioning linezolid as the preferred agent. Our objective was to assess the impact of this change within our institution. Retrospective electronic medical records review. The analysis for this observational study included eligible patients admitted to our medical center between May 1, 2011, and August 31, 2014, with ICD-9 codes for MRSA and pneumonia. Included patients were at least 18 years of age and had vancomycin or linezolid initiated at least 2 days after admission and continued for at least 2 consecutive days. The primary end points were extent of antibiotic use before and after order form change and length of stay (LOS) and hospital charges in the two treatment groups. A secondary aim was to detect any gross discrepancies in patient outcomes such as treatment duration, mechanical ventilation duration, all-cause mortality rate, nephrotoxicity, and 30-day readmission between the two treatment groups. Outcomes in 227 patients were assessed. Linezolid use increased 16.2% subsequent to the change in the order form. Although not statistically significant, the median hospital admission charge was $6200 lower in patients treated with linezolid compared with those treated with vancomycin ($25,900 vs $32,100). Hospital LOS was significantly associated with Charlson Comorbidity Index score (plinezolid treatment, and these patients were more likely to be discharged (shorter LOS). Although linezolid use increased markedly with this pathway/order form change, no negative institutional consequences or unfavorable patient outcomes were detected, justifying the change in policy from these perspectives. © 2016 Pharmacotherapy Publications, Inc.

The role of the Staphylococcal VraTSR regulatory system on vancomycin resistance and vanA operon expression in vancomycin-resistant Staphylococcus aureus.

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Qureshi, Nadia K; Yin, Shaohui; Boyle-Vavra, Susan

2014-01-01

Vancomycin is often the preferred treatment for invasive methicillin-resistant Staphylococcus aureus (MRSA) infection. With the increase in incidence of MRSA infections, the use of vancomycin has increased and, as feared, isolates of vancomycin-resistant Staphylococcus aureus (VRSA) have emerged. VRSA isolates have acquired the entercoccal vanA operon contained on transposon (Tn) 1546 residing on a conjugal plasmid. VraTSR is a vancomycin and β-lactam-inducible three-component regulatory system encoded on the S. aureus chromosome that modulates the cell-wall stress response to cell-wall acting antibiotics. Mutation in vraTSR has shown to increase susceptibility to β-lactams and vancomycin in clinical VISA strains and in recombinant strain COLVA-200 which expresses a plasmid borne vanA operon. To date, the role of VraTSR in vanA operon expression in VRSA has not been demonstrated. In this study, the vraTSR operon was deleted from the first clinical VRSA strain (VRS1) by transduction with phage harvested from a USA300 vraTSR operon deletion strain. The absence of the vraTSR operon and presence of the vanA operon were confirmed in the transductant (VRS1Δvra) by PCR. Broth MIC determinations, demonstrated that the vancomycin MIC of VRS1Δvra (64 µg/ml) decreased by 16-fold compared with VRS1 (1024 µg/ml). The effect of the vraTSR operon deletion on expression of the van gene cluster (vanA, vanX and vanR) was examined by quantitative RT-PCR using relative quantification. A 2-5-fold decreased expression of the vanA operon genes occured in strain VRS1Δvra at stationary growth phase compared with the parent strain, VRS1. Both vancomycin resistance and vancomycin-induced expression of vanA and vanR were restored by complementation with a plasmid harboring the vraTSR operon. These findings demonstrate that expression in S. aureus of the horizontally acquired enterococcal vanA gene cluster is enhanced by the staphylococcal three-component cell wall stress regulatory

Nasal carriage of Methicillin-resistant Staphylococcus aureus among healthy population of Kashmir, India

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B A Fomda

2014-01-01

Full Text Available Background: Nasal colonisation with community acquired methicillin resistant Staphylococcus aureus (CA-MRSA is being increasingly reported, especially in places where people are in close contact and where hygiene is compromised. The aim of this study was to find out prevalence of methicillin resistant S.aureus (MRSA colonising anterior nares of healthy subjects. Materials and Methods: Nasal swabs of healthy subjects were collected aseptically and cultured using standard microbiological protocols. Antibiotic susceptibility was done by Kirby-Bauer disc diffusion method according to CLSI guidelines. Methicillin resistance was detected by cefoxitin disc diffusion method and confirmed by minimum inhibitory concentration (MIC and amplification of mecA gene by PCR. Strain typing of MRSA strains was done by PFGE. Results: Out of 820 samples, S.aureus was isolated from 229 (27.92% subjects. Of the 229 isolates, 15 were methicillin resistant. All S. aureus isolates were susceptible to vancomycin. Nasal carriage of MRSA was found to be 1.83% among healthy population. The isolates were found to be polyclonal by PFGE analysis. Conclusion: High prevalence of MRSA is a cause of concern and strategies to interrupt transmission should be implemented.

Is the mazEF toxin-antitoxin system responsible for vancomycin resistance in clinical isolates of Enterococcus faecalis?

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Sadeghifard, Nourkhoda

2014-03-01

Full Text Available [english] The current study was conducted to investigate the relationship between vancomycin-resistant (VRE and the presence of toxin-antitoxin (TA system, which may be useful as target for novel antimicrobial therapy concepts. The susceptibility of was determined by MIC, and the presence of the TA system was evaluated by PCR. Among 200 isolates 39.5% showed resistance to vancomycin (VRE, while 60.5% were susceptible strains (VSE. The TA system was positive in all VRE isolates (100%, but less prevalent (38/121, 31.4% among the 121 VSE strains. In conclusion, our study demonstrated a positive relationship between the presence of vancomycin resistance and TA system. This observation may introduce therapeutic options against a novel antimicrobial target in enterococci.

Methicillin-resistant Staphylococcus aureus (MRSA)

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Methicillin-resistant Staphylococcus aureus; Hospital-acquired MRSA (HA-MRSA); Staph - MRSA; Staphylococcal - MRSA ... Centers for Disease Control and Prevention website. Methicillin-resistant Staphylococcus aureus (MRSA). www.cdc.gov/mrsa/index.html . Updated ...

Review on Usage of Vancomycin in Livestock and Humans: Maintaining Its Efficacy, Prevention of Resistance and Alternative Therapy

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Panditharathnalage Nishantha Kumara Wijesekara

2017-01-01

Full Text Available Vancomycin is one of the “last-line” classes of antibiotics used in the treatment of life-threatening infections caused by Gram-positive bacteria. Even though vancomycin was discovered in the 1950s, it was widely used after the 1980s for the treatment of infections caused by methicillin-resistant Staphylococci, as the prevalence of these strains were increased. However, it is currently evident that vancomycin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci have developed for various reasons, including the use of avaparcin—an analog of vancomycin—as a feed additive in livestock. Therefore, prophylactic and empiric use of antibiotics and their analogues need to be minimized. Herein we discuss the rational use of vancomycin in treating humans, horses, farm animals, and pet animals such as dogs, cats, and rabbits. In present day context, more attention should be paid to the prevention of the emergence of resistance to antibiotics in order to maintain their efficacy. In order to prevent emergence of resistance, proper guidance for the responsible use of antimicrobials is indispensable. Therefore, almost all stakeholders who use antibiotics should have an in-depth understanding of the antibiotic that they use. As such, it is imperative to be aware of the important aspects of vancomycin. In the present review, efforts have been made to discuss the pharmacokinetics and pharmacodynamics, indications, emergence of resistance, control of resistance, adverse effects, and alternative therapy for vancomycin.

Antibiotic resistance and virulence traits in clinical and environmental Enterococcus faecalis and Enterococcus faecium isolates.

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Rathnayake, I U; Hargreaves, M; Huygens, F

2012-07-01

This study compared virulence and antibiotic resistance traits in clinical and environmental Enterococcus faecalis and Enterococcus faecium isolates. E. faecalis isolates harboured a broader spectrum of virulence determinants compared to E. faecium isolates. The virulence traits Cyl-A, Cyl-B, Cyl-M, gel-E, esp and acm were tested and environmental isolates predominantly harboured gel-E (80% of E. faecalis and 31.9% of E. faecium) whereas esp was more prevalent in clinical isolates (67.8% of E. faecalis and 70.4% of E. faecium). E. faecalis and E. faecium isolated from water had different antibiotic resistance patterns compared to those isolated from clinical samples. Linezolid resistance was not observed in any isolates tested and vancomycin resistance was observed only in clinical isolates. Resistance to other antibiotics (tetracycline, gentamicin, ciprofloxacin and ampicillin) was detected in both clinical and water isolates. Clinical isolates were more resistant to all the antibiotics tested compared to water isolates. Multi-drug resistance was more prevalent in clinical isolates (71.2% of E. faecalis and 70.3% of E. faecium) compared to water isolates (only 5.7% E. faecium). tet L and tet M genes were predominantly identified in tetracycline-resistant isolates. All water and clinical isolates resistant to ciprofloxacin and ampicillin contained mutations in the gyrA, parC and pbp5 genes. A significant correlation was found between the presence of virulence determinants and antibiotic resistance in all the isolates tested in this study (pantibiotic resistant enterococci, together with associated virulence traits, in surface recreational water could be a public health risk. Copyright © 2012 Elsevier GmbH. All rights reserved.

Phenotypic and genotypic characterization of vancomycin-resistant Enterococcus faecium clinical isolates from two hospitals in Mexico: First detection of VanB phenotype-vanA genotype.

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Bocanegra-Ibarias, Paola; Flores-Treviño, Samantha; Camacho-Ortiz, Adrián; Morfin-Otero, Rayo; Villarreal-Treviño, Licet; Llaca-Díaz, Jorge; Martínez-Landeros, Erik Alan; Rodríguez-Noriega, Eduardo; Calzada-Güereca, Andrés; Maldonado-Garza, Héctor Jesús; Garza-González, Elvira

2016-01-01

Enterococcus faecium has emerged as a multidrug-resistant nosocomial pathogen involved in outbreaks worldwide. Our aim was to determine the antimicrobial susceptibility, biofilm production, and clonal relatedness of vancomycin-resistant E. faecium (VREF) clinical isolates from two hospitals in Mexico. Consecutive clinical isolates (n=56) were collected in two tertiary care hospitals in Mexico from 2011 to 2014. VREF isolates were characterized by phenotypic and molecular methods including pulsed-field gel electrophoresis (PFGE). VREF isolates were highly resistant to vancomycin, erythromycin, norfloxacin, high-level streptomycin, and teicoplanin, and showed lower resistance to tetracycline, nitrofurantoin and quinupristin-dalfopristin. None of the isolates were resistant to linezolid. The vanA gene was detected in all isolates. Two VanB phenotype-vanA genotype isolates, highly resistant to vancomycin and susceptible to teicoplanin, were detected. Furthermore, 17.9% of the isolates were classified as biofilm producers, and the espfm gene was found in 98.2% of the isolates. A total of 37 distinct PFGE patterns and 6 clones (25% of the isolates as clone A, 5.4% as clone B, and 3.6% each as clone C, D, E, and F) were detected. Clone A was detected in 5 different wards of the same hospital during 14 months of surveillance. The high resistance to most antimicrobial agents and the moderate cross-transmission of VREF detected accentuates the need for continuous surveillance of E. faecium in the hospital setting. This is also the first reported incidence of the E. faecium VanB phenotype-vanA genotype in the Americas. Copyright © 2015 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Vancomycin-Resistant Enterococci and Bacterial Community Structure following a Sewage Spill into an Aquatic Environment

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Young, Suzanne; Nayak, Bina; Sun, Shan; Badgley, Brian D.; Rohr, Jason R.

2016-01-01

ABSTRACT Sewage spills can release antibiotic-resistant bacteria into surface waters, contributing to environmental reservoirs and potentially impacting human health. Vancomycin-resistant enterococci (VRE) are nosocomial pathogens that have been detected in environmental habitats, including soil, water, and beach sands, as well as wildlife feces. However, VRE harboring vanA genes that confer high-level resistance have infrequently been found outside clinical settings in the United States. This study found culturable Enterococcus faecium harboring the vanA gene in water and sediment for up to 3 days after a sewage spill, and the quantitative PCR (qPCR) signal for vanA persisted for an additional week. Culturable levels of enterococci in water exceeded recreational water guidelines for 2 weeks following the spill, declining about five orders of magnitude in sediments and two orders of magnitude in the water column over 6 weeks. Analysis of bacterial taxa via 16S rRNA gene sequencing showed changes in community structure through time following the sewage spill in sediment and water. The spread of opportunistic pathogens harboring high-level vancomycin resistance genes beyond hospitals and into the broader community and associated habitats is a potential threat to public health, requiring further studies that examine the persistence, occurrence, and survival of VRE in different environmental matrices. IMPORTANCE Vancomycin-resistant enterococci (VRE) are harmful bacteria that are resistant to the powerful antibiotic vancomycin, which is used as a last resort against many infections. This study followed the release of VRE in a major sewage spill and their persistence over time. Such events can act as a means of spreading vancomycin-resistant bacteria in the environment, which can eventually impact human health. PMID:27422829

Occurrence of vancomycin-resistant Staphylococcus aureus in the oral cavity of patients with dental caries.

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Vellappally, Sajith; Divakar, Darshan Devang; Al Kheraif, Abdulaziz Abdullah; Ramakrishnaiah, Ravikumar; Alqahtani, Amer; Dalati, M H N; Anil, Sukumaran; Khan, Aftab Ahmed; Harikrishna Varma, P R

2017-09-01

Oral streptococci are the major group of microbes isolated from oral microflora. They represent frequent pathogens of infective endocarditis (IE), and it is assumed that in most of the cases oral streptococci are acquired via mucosa layer of oral cavity. Staphylococcus aureus is also frequently isolated from IE as it accounts for 20%-30% of all cases. Vancomycin has been the most reliable therapeutic agent against infections caused by methicillin-resistant S. aureus (MRSA). The main objective of this study was to examine the occurrence of S. aureus species in dental caries specimens. Antimicrobial susceptibility testing of S. aureus to four antibiotics namely vancomycin, linezolid, teicoplanin, and daptomycin was performed. Detection of vancomycin resistance was conducted using polymerase chain reaction. Among the tested 150 strains, 98 were MRSA and of that 54 were vancomycin sensitive and 27 were resistant. All 98 MRSA strains were positive for mecA and 36 yielded pvl, whereas 13 carried vanA and only 2 were positive for vanB. Majority of the isolates showed sensitivity toward daptomycin and linezolid. Strains of S. aureus exhibiting decreased susceptibility to different antibiotics like vancomycin, daptomycin, and linezolid severely compromise the therapeutic alternatives and require a considerable amount of time, public awareness, and integrative health-care strategies to prevent the emergence of resistance to these compounds.

Synergy of β-Lactams with Vancomycin against Methicillin-Resistant Staphylococcus aureus: Correlation of Disk Diffusion and Checkerboard Methods.

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Sy, Cheng Len; Huang, Tsi-Shu; Chen, Chii Shiang; Chen, Yao-Shen; Tsai, Hung-Chin; Wann, Shue-Renn; Wu, Kuan-Sheng; Chen, Jui-Kuang; Lee, Susan Shin-Jung; Liu, Yung-Ching

2016-03-01

Modified disk diffusion (MDD) and checkerboard tests were employed to assess the synergy of combinations of vancomycin and β-lactam antibiotics for 59 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and Mu50 (ATCC 700699). Bacterial inocula equivalent to 0.5 and 2.0 McFarland standard were inoculated on agar plates containing 0, 0.5, 1, and 2 μg/ml of vancomycin. Oxacillin-, cefazolin-, and cefoxitin-impregnated disks were applied to the surface, and the zones of inhibition were measured at 24 h. The CLSI-recommended checkerboard method was used as a reference to detect synergy. The MICs for vancomycin were determined using the Etest method, broth microdilution, and the Vitek 2 automated system. Synergy was observed with the checkerboard method in 51% to 60% of the isolates when vancomycin was combined with any β-lactam. The fractional inhibitory concentration indices were significantly lower in MRSA isolates with higher vancomycin MIC combinations (P synergy in MRSA isolates with bacterial inocula equivalent to McFarland standard 0.5 were 33.0% and 62.5% for oxacillin, 45.1% and 52.4% for cefazolin, and 43.1% and 52.4% for cefoxitin when combined with 0.5 and 2 μg/ml of vancomycin, respectively. Based on our study, the simple MDD method is not recommended as a replacement for the checkerboard method to detect synergy. However, it may serve as an initial screening method for the detection of potential synergy when it is not feasible to perform other labor-intensive synergy tests. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Characterization of a vancomycin-resistant Enterococcus faecalis (VREF) isolate from a dog with mastitis: further evidence of a clonal lineage of VREF in New Zealand.

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Manson, Janet M; Keis, Stefanie; Smith, John M B; Cook, Gregory M

2003-07-01

We report here on the characterization of a vancomycin-resistant Enterococcus faecalis (VREF) isolated from a dog with mastitis. The isolate was positive for the vanA, ermB, and tet(M) genes, with vanA and ermB carried on the same transferable plasmid. Comparison of this isolate with VREF from poultry and human sources in New Zealand demonstrated identical SmaI macrorestriction patterns and Tn1546-like elements. This is further evidence of a clonal lineage of VREF in New Zealand.

A laboratory study of susceptibility of methicillin resistant staphylococcus aureus (MRSA)

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Bukhari, M.H.; Iqbal, N.; Naeem, S.; Qureshi, G.R.; Naveed, I.A.; Iqbal, A.; Khatoon, N.

2004-01-01

Objective: To study the mode of infection, incidence of methicillin resistant staphylococcus aureus (MRSA) and their susceptibility against glycopeptides and fucidic acid, so that awareness may be created for consultants against such notorious rapidly spreading bacteria and recommendation can be made for their prevention and control. Methods: The specimens from various infections suspected on clinical ground were processed by standard methods and antibiotic susceptibility testing of all the 350 S. aureus and 135 MRSA isolates was done by using modified Kirby Bauer Disc diffusion technique. Results: Of 350 positive S.aureus cultures, 135 were found to be Methicillin resistant (38.5%) which showed susceptibility 96%, 94% and 86% to Vancomycin, Teicoplanin and Fucidic acid respectively. Conclusion: This study showed a high incidence of MRSA at Mayo Hospital Lahore, Glycopeptides and Fucidic acid were found to be valuable antibiotics against MRSA. (author)

Autolysis of methicillin-resistant and -susceptible Staphylococcus aureus.

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Gustafson, J E; Berger-Bächi, B; Strässle, A; Wilkinson, B J

1992-01-01

The autolytic activities, including unstimulated, Triton X-100-stimulated, and daptomycin-induced, of various sets of methicillin-resistant and related methicillin-susceptible strains were compared. Faster rates of autolysis were noted in two heterogeneous methicillin-resistant transductants than in their methicillin-susceptible parental recipients, in a heterogeneous resistant strain than in a susceptible derivative created by chemical mutagenesis, and in a homogeneous resistant strain than in a derivative that had decreased methicillin resistance and was created by transposon Tn551 mutagenesis. These results suggest that the presence of the methicillin resistance region, mec, either directly or indirectly through an interaction with other host genes, confers a faster rate of autolysis on strains. Various auxilliary genes are known to affect methicillin resistance expression, and one of these genes, femA, was necessary for the expression of this faster rate of autolysis. These differences in autolytic activities were not observed in isolated crude cell walls retaining autolytic activities, suggesting different modes of regulation of autolysins in intact cells and isolated walls. In contrast, one homogeneous, highly resistant strain, DU4916, had a lower autolytic activity than did derived heterogeneous resistant and susceptible strains created by chemical mutagenesis and a strain that had decreased resistance and was created by transposon mutagenesis. Our observations suggest that methicillin resistance expression is associated with an enhanced rate of autolysis, in heterogeneous resistant strains at least. Images PMID:1320363

Prevalence of Methicillin-Resistant Staphylococcus aureus among ...

African Journals Online (AJOL)

Purpose: To determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in apparently healthy ... treatment failures is vital. Keywords: Methicillin-resistant Staphylococcus aureus, Nasal swabs, Multidrug resistance, Rational .... defined as resistance to three or more classes of antibiotics other than the ...

AUC/MIC Pharmacodynamic Target Is Not a Good Predictor of Vancomycin Efficacy in Methicillin-Resistant Staphylococcus aureus Experimental Endocarditis.

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Castañeda, Ximena; García-de-la-Mària, Cristina; Gasch, Oriol; Pericas, Juan M; Armero, Yolanda; Soy, Dolors; García-González, Javier; Falces, Carlos; Ninot, Salvador; Almela, Manel; Ambrosioni, Juan; Quintana, Eduardo; Vidal, Barbara; Fuster, David; Llopis, Jaume; Soto, Sara; Moreno, Asuncion; Marco, Francesc; Miró, Jose M

2017-06-01

The aim of this in vivo study was to compare the efficacy of vancomycin at standard doses (VAN-SD) to that of VAN at adjusted doses (VAN-AD) in achieving a VAN area under the curve/MIC ratio (AUC/MIC) of ≥400 against three methicillin-resistant Staphylococcus aureus (MRSA) strains with different microdilution VAN MICs in an experimental endocarditis model. The valve vegetation bacterial counts after 48 h of VAN therapy were compared, and no differences were observed between the two treatment groups for any of the three strains tested. Overall, for VAN-SD and VAN-AD, the rates of sterile vegetations were 15/45 (33.3%) and 21/49 (42.8%) ( P = 0.343), while the medians (interquartile ranges [IQRs]) for log 10 CFU/g of vegetation were 2 (0 to 6.9) and 2 (0 to 4.5) ( P = 0.384), respectively. In conclusion, this VAN AUC/MIC pharmacodynamic target was not a good predictor of vancomycin efficacy in MRSA experimental endocarditis. Copyright © 2017 American Society for Microbiology.

Repurposing Clinical Molecule Ebselen to Combat Drug Resistant Pathogens.

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Thangamani, Shankar; Younis, Waleed; Seleem, Mohamed N

2015-01-01

Without a doubt, our current antimicrobials are losing the battle in the fight against newly-emerged multidrug-resistant pathogens. There is a pressing, unmet need for novel antimicrobials and novel approaches to develop them; however, it is becoming increasingly difficult and costly to develop new antimicrobials. One strategy to reduce the time and cost associated with antimicrobial innovation is drug repurposing, which is to find new applications outside the scope of the original medical indication of the drug. Ebselen, an organoselenium clinical molecule, possesses potent antimicrobial activity against clinical multidrug-resistant Gram-positive pathogens, including Staphylococcus, Streptococcus, and Enterococcus, but not against Gram-negative pathogens. Moreover, the activity of ebselen against Gram-positive pathogens exceeded those activities determined for vancomycin and linezolid, drugs of choice for treatment of Enterococcus and Staphylococcus infections. The minimum inhibitory concentrations of ebselen at which 90% of clinical isolates of Enterococcus and Staphylococcus were inhibited (MIC90) were found to be 0.5 and 0.25 mg/L, respectively. Ebselen showed significant clearance of intracellular methicillin-resistant S. aureus (MRSA) in comparison to vancomycin and linezolid. We demonstrated that ebselen inhibits the bacterial translation process without affecting mitochondrial biogenesis. Additionally, ebselen was found to exhibit excellent activity in vivo in a Caenorhabditis elegans MRSA-infected whole animal model. Finally, ebselen showed synergistic activities with conventional antimicrobials against MRSA. Taken together, our results demonstrate that ebselen, with its potent antimicrobial activity and safety profiles, can be potentially used to treat multidrug resistant Gram-positive bacterial infections alone or in combination with other antibiotics and should be further clinically evaluated.

Nasal Carriage Rate of Methicillin Resistant Staphylococcus aureus among Health Care Workers at a Tertiary Care Hospital in Kathmandu, Nepal.

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Khatri, S; Pant, N D; Bhandari, R; Shrestha, K L; Shrestha, C D; Adhikari, N; Poudel, A

2017-01-01

Methicillin-resistant Staphylococcus aureus is one of the most common causes of nosocomial infections. Due to its multidrug resistant nature; infections due to Methicillin-resistant Staphylococcus aureus are often very difficult to treat. Colonized health care workers are the important sources of Methicillin-resistant Staphylococcus aureus. The objectives of this study were to determine the nasal carriage rate of Methicillin-resistant Staphylococcus aureus among health care workers at Kathmandu Medical College and Teaching Hospital, Nepal and to assess their antimicrobial susceptibility patterns. A cross sectional study was conducted among 252 health care workers from July to November 2013. Mannitol salt agar was used to culture the nasal swabs. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion technique following Clinical and Laboratory Standards Institute guidelines. Methicillin-resistant Staphylococcus aureus strains were confirmed by using cefoxitin disc and by determining the minimum inhibitory concentration of oxacillin by agar dilution method. Of 252 healthcare workers, 46(18.3%) were positive for Staphylococcus aureus among which 19(41.3%) were Methicillin-resistant Staphylococcus aureus carriers. Overall rate of nasal carriage of Methicillin-resistant Staphylococcus aureus was 7.5% (19/252).The higher percentages of lab personnel were nasal carriers of S. aureus (31.6%) and Methicillin-resistant Staphylococcus aureus (10.5%).The percentages of nasal carriage of S. aureus (35.7%) and Methicillin-resistant Staphylococcus aureus (14.3%) were highest in the health care workers from post operative department. Higher percentage of Methicillin-resistant Staphylococcus aureus were susceptible toward amikacin (100%) and vancomycin (100%) followed by cotrimoxazole (84.2%). High rates of nasal carriage of S. aureus and Methicillin-resistant Staphylococcus aureus were observed among the healthcare workers, which indicate the need of

Prevalence and antimicrobial susceptibility pattern of methicillin resistant Staphylococcus aureus: A multicentre study.

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Rajaduraipandi K

2006-01-01

Full Text Available Purpose: Methicillin resistant Staphylococcus aureus (MRSA is an important nosocomial pathogen. We report the prevalence and antibiotic susceptibility pattern of MRSA in major southern districts of Tamilnadu. Methods: A total of 7172 clinical specimens and 1725 carrier screening samples were collected from different centers and subjected to MRSA screening using conventional microbiological methods. Subsequently the antibiotic sensitivity test was performed for the confirmed MRSA isolates. Results: Out of 906 strains of S. aureus isolated from clinical and carrier samples, 250 (31.1% and 39 (37.9% were found to be methicillin resistant respectively. Almost all clinical MRSA strains (99.6% were resistant to penicillin, 93.6% to ampicillin, and 63.2% towards gentamicin, co-trimoxazole, cephalexin, erythromycin, and cephotaxime. All MRSA strains (100% of carrier screening samples had resistance to penicillin and about 71.8% and 35.9% were resistant to ampicillin and co-trimoxazole respectively. Multidrug resistance was observed among 63.6% of clinical and 23% of carrier MRSA isolates. However, all strains of clinical and carrier subjects were sensitive to vancomycin. Conclusion: The determination of prevalence and antibiotic sensitivity pattern of MRSA will help the treating clinicians for first line treatment in referral hospitals.

The Impact of AUC-Based Monitoring on Pharmacist-Directed Vancomycin Dose Adjustments in Complicated Methicillin-Resistant Staphylococcus aureus Infection.

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Stoessel, Andrew M; Hale, Cory M; Seabury, Robert W; Miller, Christopher D; Steele, Jeffrey M

2018-01-01

This study aimed to assess the impact of area under the curve (AUC)-based vancomycin monitoring on pharmacist-initiated dose adjustments after transitioning from a trough-only to an AUC-based monitoring method at our institution. A retrospective cohort study of patients treated with vancomycin for complicated methicillin-resistant Staphylococcus aureus (MRSA) infection between November 2013 and December 2016 was conducted. The frequency of pharmacist-initiated dose adjustments was assessed for patients monitored via trough-only and AUC-based approaches for trough ranges: 10 to 14.9 mg/L and 15 to 20 mg/L. Fifty patients were included: 36 in the trough-based monitoring and 14 in the AUC-based-monitoring group. The vancomycin dose was increased in 71.4% of patients when troughs were 10 to 14.9 mg/L when a trough-only approach was used and in only 25% of patients when using AUC estimation ( P = .048). In the AUC group, the dose was increased only when AUC/minimum inhibitory concentration (MIC) AUC/MIC ≥400. The AUC-based monitoring did not significantly increase the frequency of dose reductions when trough concentrations were 15 to 20 mg/L (AUC: 33.3% vs trough: 4.6%; P = .107). The AUC-based monitoring resulted in fewer patients with dose adjustments when trough levels were 10 to 14.9 mg/L. The AUC-based monitoring has the potential to reduce unnecessary vancomycin exposure and warrants further investigation.

Controlling antibiotic resistance in the ICU

NARCIS (Netherlands)

Derde, L.P.G.

2013-01-01

Patients admitted to intensive care units (ICUs) are frequently colonized with (antibiotic-resistant) bacteria, which may lead to healthcare associated infections. Antimicrobial-resistant bacteria (AMRB), such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci

In vitro synergy of baicalein and gentamicin against vancomycin-resistant Enterococcus.

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Chang, Ping Chin; Li, Hua Yu; Tang, Hung Jen; Liu, Jien Wei; Wang, Jhi Joung; Chuang, Yin Ching

2007-02-01

Little is known about the possible synergism of baicalein, a bioactive flavone of Scutellariae radix (a Chinese herb), when used in conjunction with other antimicrobial agents against vancomycin-resistant Enterococcus (VRE). This in vitro study examined the possible synergism of the combination of baicalein and gentamicin against VRE. Minimal inhibitory concentrations (MICs) of baicalein as well as gentamicin were determined against 39 clinical isolates of VRE by the agar dilution method. Synergistic activities were determined using the checkerboard method based on the fractional inhibitory concentration indices and also the time-kill method. Further time-kill studies were conducted with these two agents against one randomly chosen clinical isolate, VRE-096. Minimal concentrations inhibiting 50% (MIC(50)) and 90% (MIC(90)) of isolates for baicalein and gentamicin were all >256 microg/mL. Synergism between baicalein and gentamicin was demonstrated against four clinical isolates of VRE (VRE-70, VRE-940, VRE-096 and VRE-721). When approximately 5 x 10(5) colony-forming units/mL of VRE-096 was incubated with both baicalein at a concentration of 32 microg/mL (1/8 x MIC) and gentamicin at a concentration of 128 microg/mL (1/2 x MIC), there was an inhibitory effect against VRE that persisted for 48 h. At 48 h, the combination of baicalein and gentamicin at these respective concentrations resulted in a reduction of growth by approximately 2 orders of magnitude compared to that for the starting inoculum and by 3 orders of magnitude compared to that for baicalein alone, the more active single agent. This study demonstrated that baicalein and gentamicin can act synergistically in inhibiting VRE in vitro.

Epidemiological alteration in pathogens found in ground meat in Iran: unexpected predominance of vancomycin-resistant Enterococcus faecalis

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Sadeghifard, Nourkhoda

2015-07-01

Full Text Available Colonization of the human and animal intestinal tract with potential pathogenic bacteria is correlated with the risk of contamination of food products. The current study analyzed the prevalence of and O157H7 in ground meat in Ilam, Iran. Both index organisms were identified following standard food microbiological methods. For , the susceptibility to vancomycin was tested, and PCR was used to check for the gene. was present in all 24 ground meat samples, with no O157H7 detected in samples. The analysis showed the presence of the gene in 5/24 vancomycin resistant enterococci. In conclusion, this study for the first time demonstrates the presence of vancomycin-resistant enterococci in ground meat in Iran. This observation warrants further epidemiologic investigation and should be followed up in the future.

Modeling the economic impact of linezolid versus vancomycin in confirmed nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus.

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Patel, Dipen A; Shorr, Andrew F; Chastre, Jean; Niederman, Michael; Simor, Andrew; Stephens, Jennifer M; Charbonneau, Claudie; Gao, Xin; Nathwani, Dilip

2014-07-22

We compared the economic impacts of linezolid and vancomycin for the treatment of hospitalized patients with methicillin-resistant Staphylococcus aureus (MRSA)-confirmed nosocomial pneumonia. We used a 4-week decision tree model incorporating published data and expert opinion on clinical parameters, resource use and costs (in 2012 US dollars), such as efficacy, mortality, serious adverse events, treatment duration and length of hospital stay. The results presented are from a US payer perspective. The base case first-line treatment duration for patients with MRSA-confirmed nosocomial pneumonia was 10 days. Clinical treatment success (used for the cost-effectiveness ratio) and failure due to lack of efficacy, serious adverse events or mortality were possible clinical outcomes that could impact costs. Cost of treatment and incremental cost-effectiveness per successfully treated patient were calculated for linezolid versus vancomycin. Univariate (one-way) and probabilistic sensitivity analyses were conducted. The model allowed us to calculate the total base case inpatient costs as $46,168 (linezolid) and $46,992 (vancomycin). The incremental cost-effectiveness ratio favored linezolid (versus vancomycin), with lower costs ($824 less) and greater efficacy (+2.7% absolute difference in the proportion of patients successfully treated for MRSA nosocomial pneumonia). Approximately 80% of the total treatment costs were attributed to hospital stay (primarily in the intensive care unit). The results of our probabilistic sensitivity analysis indicated that linezolid is the cost-effective alternative under varying willingness to pay thresholds. These model results show that linezolid has a favorable incremental cost-effectiveness ratio compared to vancomycin for MRSA-confirmed nosocomial pneumonia, largely attributable to the higher clinical trial response rate of patients treated with linezolid. The higher drug acquisition cost of linezolid was offset by lower treatment failure

Screening of nasal carriage of methicillin-resistant Staphylococcus aureus during admission of patients to Frantz Fanon Hospital, Blida, Algeria

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Mohamed Amine Ouidri

2018-05-01

Full Text Available A study was performed of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA strains isolated from nasal preoperative samples. Of 663 samples assessed, staphylococcus was detected in 143 (21.57%. The disc diffusion method (cefoxitin 30 μg, a screening test (oxacillin 6 μg/mL and a search for Protein Binding Additional Penicillin 2 (PLP2a allowed the detection and confirmation of resistance to methicillin for 36 strains, a rate of 5.43% of the total population studied. Eight MRSA carriers received care in the trauma service, 14 in cardiology, five in ear, nose and throat, four in neurosurgery and paediatrics, and one in SCI. Thirty-six methicillin-resistant of the nasal portage strains are in their great majority, 27 of 36, rather limited multi-R character (two to three families namely resistance: tetracyclines, fluoroquinolones, aminoglycosides, macrolides. One of the MRSA strains was found to have intermediate sensitivity to vancomycin. Keywords: Antibiotic resistance, Healthy volunteers, MRSA, Prevalence, Staphylococcus aureus

Molecular epidemiology of clinical and carrier strains of methicillin resistant Staphylococcus aureus (MRSA in the hospital settings of north India

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Dar Mohammad J

2006-09-01

Full Text Available Abstract Background The study was conducted between 2000 and 2003 on 750 human subjects, yielding 850 strains of staphylococci from clinical specimens (575, nasal cultures of hospitalized patients (100 and eye & nasal sources of hospital workers (50 & 125 respectively in order to determine their epidemiology, acquisition and dissemination of resistance genes. Methods Organisms from clinical samples were isolated, cultured and identified as per the standard routine procedures. Susceptibility was measured by the agar diffusion method, as recommended by the Nat ional Committee for Clinical Laboratory Standards (NCCLS. The modified method of Birnboin and Takahashi was used for isolation of plasmids from staphylococci. Pulsed-field gel electrophoresis (PFGE typing of clinical and carrier Methicillin resistant Staphylococcus aureus (MRSA strains isolated during our study was performed as described previously. Results It was shown that 35.1% of Staphylococcus aureus and 22.5% of coagulase-negative staphylococcal isolates were resistant to methicillin. Highest percentage of MRSA (35.5% was found in pus specimens (n = 151. The multiple drug resistance of all MRSA (n = 180 and Methicillin resistant Coagulase-negative Staphylococcus aureus (MRCNS (n = 76 isolates was detected. In case of both methicillin-resistant as well as methicillin-sensitive Saphylococcal isolates zero resistance was found to vancomycin where as highest resistance was found to penicillin G followed by ampicillin. It was shown that the major reservoir of methicillin resistant staphylococci in hospitals are colonized/infected inpatients and colonized hospital workers, with carriers at risk for developing endogenous infection or transmitting infection to health care workers and patients. The results were confirmed by molecular typing using PFGE by SmaI-digestion. It was shown that the resistant markers G and T got transferred from clinical S. aureus (JS-105 to carrier S. aureus (JN-49

Genomic organization of a vancomycin-resistant staphylococcus aureus

International Nuclear Information System (INIS)

Mirani, A.Z.; Jamil, N.

2013-01-01

Objective: To study the genomic organization of vancomycin resistance in a local isolate of vancomycin resistant Staphylococcus aureus (VRSA). Study Design: Experimental study. Place and Duration of Study: Department of Microbiology, University of Karachi, January 2008 through December 2010. Methodology: A vancomycin-resistant Staphylococcus aureus (VRSA-CP2) isolate (MIC 16 mu g/ml) was isolated from a local hospital of Karachi. Species identification was confirmed by Gram staining, standard biochemical tests and PCR amplification of the nuc gene. The vancomycin MIC was re-confirmed by E-test. For the genetic determination of vancomycin resistance, in-vitro amplification of vanA cassette was performed by using plasmid DNA of CP2, CP2's transformant as template on MWG Thermo-Cycler. Amplified products of vanR, vanS, vanH, vanA, vanY, orf2, orf1D, orf2E, orf-Rev and IS element genes were subjected to Sanger's electrophoresis based sequence determination using specific primers. The Basic Local Alignment Search Tool (BLAST) algorithm was used to identify sequences in GenBank with similarities to the vanA cassette genes. Results: The vancomycin-resistant isolate CP2 was found to be resistant to oxacillin, chloramphenicol, erythromycin, rifampicin, gentamicin, tetracycline and ciprofloxacin, as well. The isolate CP2 revealed four bands: one of large molecular size approx 56.4 kb and three of small size approx 6.5 kb, approx 6.1 kb and approx 1.5 kb by agarose gel electrophoresis indicating the presence of 3 plasmids. The plasmid DNA of isolate CP2 was analyzed by PCR for the presence of the van cassettes with each of the vanA , vanB and vanC specific primers. It carried vanA cassette, which comprises of vanR, vanS, vanH, vanA, vanY, and orf2. The vanA cassette of isolate CP2 also carried an insertion element (IS). However, it did not show the PCR product for orf1. Vancomycin resistance was successfully transferred from the donor CP2 to a vancomycin-sensitive recipient S

Bactericidal antibiotic-phytochemical combinations against methicillin resistant Staphylococcus aureus

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Bhone Myint Kyaw

2012-09-01

Full Text Available Methicillin resistant Staphylococcus aureus (MRSA infection is a global concern nowadays. Due to its multi-drug resistant nature, treatment with conventional antibiotics does not assure desired clinical outcomes. Therefore, there is a need to find new compounds and/or alternative methods to get arsenal against the pathogen. Combination therapies using conventional antibiotics and phytochemicals fulfill both requirements. In this study, the efficacy of different phytochemicals in combination with selected antibiotics was tested against 12 strains of S. aureus (ATCC MRSA 43300, ATCC methicillin sensitive S. aureus or MSSA 29213 and 10 MRSA clinical strains collected from National University Hospital, Singapore. Out of the six phytochemicals used, tannic acid was synergistic with fusidic acid, minocycline, cefotaxime and rifampicin against most of strains tested and additive with ofloxacin and vancomycin. Quercetin showed synergism with minocycline, fusidic acid and rifampicin against most of the strains. Gallic acid ethyl ester showed additivity against all strains in combination with all antibiotics under investigation except with vancomycin where it showed indifference effect. Eugenol, menthone and caffeic acid showed indifference results against all strains in combination with all antibiotics. Interestingly, no antagonism was observed within these interactions. Based on the fractional inhibitory concentration indices, synergistic pairs were further examined by time-kill assays to confirm the accuracy and killing rate of the combinations over time. The two methods concurred with each other with 92% accuracy and the combinatory pairs were effective throughout the 24 hours of assay. The study suggests a possible incorporation of effective phytochemicals in combination therapies for MRSA infections.

Enterococcus spp. Resistant to Multiple Antimicrobial Drugs and Determination of Fecal Contamination Levels in Mangrove Oysters (Crassostrea rhizophorae

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Cynthia Annes Rubião

2017-08-01

Full Text Available ABSTRACT The aim of this study was to determine and compare the Most Probable Number (MPN of Total Coliforms (TC, Escherichia coli and Enterococcus spp. and to characterize the antimicrobial resistance profiles of Enterococcus spp. isolated from oysters collected in the Barra de Guaratiba Mangrove, Rio de Janeiro, Brazil. The enumeration of E. coli has been used to indicate fecal contamination and hygienic-sanitary conditions of bivalve molluscs. Enterococci are capable to transfer several antimicrobial resistance genes to pathogenic bacteria, including those from Gram-negative group. The oysters were bought from local fishermen and a total of 123 individuals were analyzed. The TC, E. coli and Enterococcus spp. MPN mean were 26,300/100 g, 3,260/100 g and 2,820/100 g, respectively. The only correlation found was between TC and E. coli. Two strains of Enterococcus spp. were resistant to three different antimicrobial categories, including a high level resistance to streptomycin. One strain presented intermediate resistance to vancomycin. The E. coli levels exceeded the limits established by international legislation. This microbiological contamination in oysters reflects the water pollution and indicates a probable contamination of other seafood species from this mangrove, which can represent a risk for consumers and a threat to the environment and public health.

Antibacterial susceptibility patterns and cross-resistance of methicillin resistant and sensitive Staphyloccus aureus isolated from the hospitalized patients in Shiraz, Iran

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Aziz Japoni

2010-10-01

Full Text Available Nosocomial infections caused by methicillin-resistant staphylococci (MRSA pose a serious problem in many countries. This study aimed to determine the antibacterial susceptibility patterns of methicillin sensitive and resistant Staphylococcus aureus isolates from the hospitalized patients. Totally 356 isolates of Staphylococcus aureus (S. aureus including 200, 137 and 19 corresponding to MSSA, MRSA, and intermediate MRSA strains, respectively were isolated. Antibacterial susceptibility patterns of the isolates to 14 antibiotics were examined using Kirby-Bauer method. MICs of 15 antibiotics to 156 MRSA isolates were determined by E test method. Cross-resistances of MRSA isolates (137+19 to the other tested antibiotics were also determined. S.aureus with high frequencies were isolated from the blood, sputum and deep wound samples. All of 200 MSSA isolates were sensitive to oxacillin, vancomycin, tecoplanin, rifampin, linezolid, quinupristin/dalfopristin, mupirocin and fusidic acid. A gradient of reduced susceptibility of MSSA to cephalexin, co-trimoxazole, ciprofloxacin, clindamycin, tetracycline, erythromycin and gentamicin were evident. MRSA isolates were sensitive to vancomycin, tecoplanin, linezolid, quinupristin/dalfopristin, mupirocin and fusidic acid, while reduced susceptibility of them to rifampin, co-trimoxazole, clindamycin, cephalexin, tetracycline, ciprofloxacin, erythromycin and gentamicin were observed. MRSA isolates exhibited a high range of cross-resistance to the eight tested antibiotics. Overall, co-trimoxazole, ciprofloxacin, clindamycin, tetracycline, erythromycin and gentamicin showed low activity against MSSA and MRSA isolates which may indicate they are not suitable to be used in clinical practices. To preserve the effectiveness of antibiotics, rational prescription and concomitant application of preventive measures against the spread of MRSA are recommended.

Evolution of methicillin-resistant Staphylococcus aureus towards increasing resistance

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Strommenger, Birgit; Bartels, Mette Damkjær; Kurt, Kevin

2014-01-01

To elucidate the evolutionary history of Staphylococcus aureus clonal complex (CC) 8, which encompasses several globally distributed epidemic lineages, including hospital-associated methicillin-resistant S. aureus (MRSA) and the highly prevalent community-associated MRSA clone USA300.......To elucidate the evolutionary history of Staphylococcus aureus clonal complex (CC) 8, which encompasses several globally distributed epidemic lineages, including hospital-associated methicillin-resistant S. aureus (MRSA) and the highly prevalent community-associated MRSA clone USA300....

Repurposing Clinical Molecule Ebselen to Combat Drug Resistant Pathogens.

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Shankar Thangamani

Full Text Available Without a doubt, our current antimicrobials are losing the battle in the fight against newly-emerged multidrug-resistant pathogens. There is a pressing, unmet need for novel antimicrobials and novel approaches to develop them; however, it is becoming increasingly difficult and costly to develop new antimicrobials. One strategy to reduce the time and cost associated with antimicrobial innovation is drug repurposing, which is to find new applications outside the scope of the original medical indication of the drug. Ebselen, an organoselenium clinical molecule, possesses potent antimicrobial activity against clinical multidrug-resistant Gram-positive pathogens, including Staphylococcus, Streptococcus, and Enterococcus, but not against Gram-negative pathogens. Moreover, the activity of ebselen against Gram-positive pathogens exceeded those activities determined for vancomycin and linezolid, drugs of choice for treatment of Enterococcus and Staphylococcus infections. The minimum inhibitory concentrations of ebselen at which 90% of clinical isolates of Enterococcus and Staphylococcus were inhibited (MIC90 were found to be 0.5 and 0.25 mg/L, respectively. Ebselen showed significant clearance of intracellular methicillin-resistant S. aureus (MRSA in comparison to vancomycin and linezolid. We demonstrated that ebselen inhibits the bacterial translation process without affecting mitochondrial biogenesis. Additionally, ebselen was found to exhibit excellent activity in vivo in a Caenorhabditis elegans MRSA-infected whole animal model. Finally, ebselen showed synergistic activities with conventional antimicrobials against MRSA. Taken together, our results demonstrate that ebselen, with its potent antimicrobial activity and safety profiles, can be potentially used to treat multidrug resistant Gram-positive bacterial infections alone or in combination with other antibiotics and should be further clinically evaluated.

Efficacy of linezolid compared to vancomycin in an experimental model of pneumonia induced by methicillin-resistant Staphylococcus aureus in ventilated pigs.

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Martinez-Olondris, Pilar; Rigol, Montserrat; Soy, Dolors; Guerrero, Laura; Agusti, Carlos; Quera, Maria Angels; Li Bassi, Gianluigi; Esperatti, Mariano; Luque, Nestor; Liapikou, Manto; Filella, Xavier; Marco, Francesc; de la Bellacasa, Jordi Puig; Torres, Antoni

2012-01-01

To assess the efficacy of linezolid compared with vancomycin in an experimental model of pneumonia induced by methicillin-resistant Staphylococcus aureus (MRSA) in ventilated pigs. Forty pigs (30 kg) were intubated and challenged via bronchoscopy with a suspension of 106 colony forming units of MRSA into every lobe. Afterwards, pigs were ventilated up to 96 hours. Twelve hours after bacterial inoculation, the animals were randomized into 4 groups of treatment: group 1, control; group 2, vancomycin twice daily; group 3, continuous infusion of vancomycin; and group 4, linezolid. Clinical and laboratory parameters were monitored throughout the study. Bacterial cultures of bronchoalveolar lavage fluid and lung tissue samples were performed at the end of the study. Measurements of histopathology derangements of lung samples and studies of intrapulmonary drug penetration were performed. A total of 34 animals completed the study. No differences in clinical and laboratory parameters were observed. The percentage of bronchoalveolar lavage fluid and lung tissue samples with positive cultures for MRSA in controls and groups 2, 3, and 4 was respectively 75%, 11%, 11%, and 0% (p pneumonia in 95%, 69%, 58%, and 57% and signs of severe pneumonia in 48%, 29%, 22%, and 0% of controls and groups 2, 3, and 4, respectively (p treatments. In this animal model of MRSA pneumonia, linezolid showed a better efficacy than vancomycin showed because of a better pharmacokinetics/pharmacodynamics index.

Prevalence and genotypic relatedness of methicillin resistant Staphylococcus aureus in a tertiary care hospital

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B A Fomda

2014-01-01

Full Text Available Background: Methicillin-resistant Staphylococcus aureus (MRSA is the most common multidrug-resistant pathogen causing nosocomial infections across the world. MRSA is not only associated with significant mortality and morbidity but also places a large economic strain on our health care system. MRSA isolates are also typically resistant to multiple, non-β-lactam antibiotics. We conducted a prospective study in a tertiary care hospital, to determine the prevalence of MRSA and to establish the clonal distribution of MRSA isolates recovered from various clinical specimens. Materials and Methods: Clinical samples were cultured and S. aureus was identified as per standard microbiological procedures. Susceptibility testing was done by agar disk diffusion and minimum inhibitory concentration (MIC method as recommended by CLSI. Methicillin resistance was detected by phenotypic methods namely, oxacillin disc diffusion (ODD, minimum inhibitory concentration (MIC of oxacillin, cefoxitin disk diffusion (CDD, and MIC of cefoxitin. Amplification of mecA gene by PCR was used as gold standard for detection of methicillin resistance. Pulsed field gel electrophoresis (PFGE typing was performed for MRSA isolates. Results: Out of 390 S. aureus isolates, 154 (39.48% isolates were MRSA and 236 (60.51% isolates were MSSA. Penicillin was the least effective antibacterial drug against the hospital associated S. aureus isolates with 85.64% resistance rate. All the isolates were susceptible to vancomycin. The MRSA showed a high level of resistance to all antimicrobials in general in comparison to the MSSA and the difference was statistically significant (P < 0.05. Multiplex PCR performed for all strains showed amplification of both the mecA and nucA genes in MRSA strains whereas MSSA strains showed amplification of only nucA gene. PFGE of these isolates showed 10 different patterns. Conclusion: Prevalence of MRSA in our hospital was 39.48%. Most of these isolates were

Isolation of vancomycin-resistant Enterococcus from apparently healthy human animal attendants, cattle and cattle wastes in Tanzania

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Madoshi, B. P.; Mtambo, M. M.A.; Muhairwa, A. P.

2018-01-01

faecalis was the most prevalent species from all sources of isolation (43·5%), followed by Enterococcus faecium (38·4%). Isolates of E. faecium showed a higher number of phenotypic antimicrobial resistance than isolates of E. faecalis. Fifty-eight isolates, which showed resistance or intermediate...

Antimicrobial resistance in gram-positive pathogens isolated in the UK between October 1996 and January 1997.

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Andrews, J; Ashby, J; Jevons, G; Lines, N; Wise, R

1999-05-01

Antimicrobial resistance in gram-positive pathogens from 30 centres in the UK (ten Teaching, ten Associate Teaching and ten District General Hospitals) was studied over a 4 month period between October 1996 and January 1997. High-level resistance (HLR) and low-level resistance (LLR) to penicillin amongst pneumococci was 3.3% and 3.4%, respectively. However, considerable variation in resistance rates was observed depending on geographical location (LLR range 0-15.4% and HLR range 0-30.8%). Considerable variation in resistance rates was also observed for Staphylococcus aureus to methicillin, with rates ranging from 0% to 56.7% depending on locality. Using conventional MIC methodology, none of the isolates of S. aureus was considered as having reduced sensitivity to vancomycin. However, eight isolates grew on Brain Heart Infusion Agar containing vancomycin (4 mg/L) after prolonged incubation and are therefore worthy of further investigation by electron microscopy. With Enterococcus faecalis, resistance rates were similar between the three types of hospital and only four isolates were considered resistant to glycopeptide antibiotics (one vanA and three vanB phenotype).

Frequency of methicillin resistant Staphylococcus aureus in health care

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Somayeh Rahimi-Alang

2011-03-01

Full Text Available Background: Methicillin resistant Staphylococcus aureus (MRSA is one of the most important pathogen in hospitals. Healthcare personnel are the main source of nosocomial infections and identification and control of MRSA carriers can reduce incidence of infections. The aim of this study was to determine the prevalence of MRSA and their antibiotic susceptibility profile among healthcare workers in Gorgan.Materials and Method: 333 healthcare workers were participated in this cross-sectional study in 2009. Samples were taken with sterile cotton swabs from both anterior nares and hands. Swabs were plated immediately on to the mannitol salt agar. Suspected colonies were confirmed as S. aureus by Gram staining, catalase, coagulase and DNase tests. Minimum inhibition concentration by micro dilution broth method was used to determine methicillin resistant strains. Antimicrobial susceptibility to other antibiotics was performed according to NCCLS guidelines by disc diffusion method.Result: Frequency of S.aureus and MRSA carriers among healthcare workers was 24% and 3% respectively. The highest rate of S. aureus and MRSA carriers were observed in operating room staff. Resistance to penicillin was seen in 97.5% of isolates and all strains were sensitive to vancomycin.Conclusions: Frequency of S. aureus and MRSA in healthcare workers was median and rather low respectively. Continual monitoring and control of carriers can reduce distribution of this organism and their infections

Prevalence and antimicrobial susceptibility pattern of methicillin resistant Staphylococcus aureus isolates from Trinidad & Tobago

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Monteil Michele

2006-07-01

Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA has become increasingly prevalent worldwide since it was first reported in a British hospital. The prevalence however, varies markedly in hospitals in the same country, and from one country to another. We therefore sought to document comprehensively the prevalence and antimicrobial susceptibility pattern of MRSA isolates in Trinidad and Tobago. Methods All Staphylococcus aureus isolates encountered in routine clinical specimens received at major hospitals in the country between 2000 and 2001 were identified morphologically and biochemically by standard laboratory procedures including latex agglutination test (Staphaurex Plus; Murex Diagnostics Ltd; Dartford, England; tube coagulase test with rabbit plasma (Becton, Dickinson & Co; Sparks, MD, USA, and DNase test using DNase agar (Oxoid Ltd; Basingstoke, Hampshire, England. MRSA screening was performed using Mueller-Hinton agar containing 6 μg oxacillin and 4% NaCl, latex agglutination test (Denka Seiken Co. Ltd, Tokyo, Japan and E-test system (AB Biodisk, Solna, Sweden. Susceptibility to antimicrobial agents was determined by the modified Kirby Bauer disc diffusion method while methicillin MICs were determined with E-test system. Results Of 1,912 S. aureus isolates received, 12.8% were methicillin (oxacillin resistant. Majority of the isolates were recovered from wound swabs (86.9% and the least in urine (0.4% specimens. Highest number of isolates was encountered in the surgical (62.3% and the least from obstetrics and gynaecology (1.6% facilities respectively. Large proportions of methicillin sensitive isolates are >85% sensitive to commonly used and available antimicrobials in the country. All MRSA isolates were resistant to ceftriaxone, erythromycin, gentamicin and penicillin but were 100% sensitive to vancomycin, rifampin and chloramphenicol. Conclusion There is a progressive increase in MRSA prevalence in the country but

Identification, antimicrobial resistance and genotypic characterization of Enterococcus spp. isolated in Porto Alegre, Brazil

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Bender, Eduardo André; de Freitas, Ana Lúcia Peixoto; Reiter, Keli Cristine; Lutz, Larissa; Barth, Afonso Luís

2009-01-01

In the past two decades the members of the genus Enterococcus have emerged as important nosocomial pathogens worldwide. In the present study, we evaluated the antimicrobial resistance and genotypic characteristics of 203 Enterococcus spp. recovered from different clinical sources from two hospitals in Porto Alegre, Rio Grande do Sul, Brazil. The species were identified by conventional biochemical tests and by an automated system. The genetic diversity of E. faecalis presenting high-level aminoglycoside resistance (HLAR) was assessed by pulsed-field gel electrophoresis of chromosomal DNA after SmaI digestion. The E. faecalis was the most frequent specie (93.6%), followed by E. faecium (4.4%). The antimicrobial resistance profile was: 2.5% to ampicillin, 0.5% to vancomycin, 0.5% teicoplanin, 33% to chloramphenicol, 2% to nitrofurantoin, 66.1% to erythromycin, 66.5% to tetracycline, 24.6% to rifampicin, 30% to ciprofloxacin and 87.2% to quinupristin-dalfopristin. A total of 10.3% of the isolates proved to be HLAR to both gentamicin and streptomycin (HLR-ST/GE), with 23.6% resistant only to gentamicin (HLR-GE) and 37.4% only to streptomycin (HLR-ST). One predominant clonal group was found among E. faecalis HLR-GE/ST. The prevalence of resistance among beta-lactam antibiotics and glycopeptides was very low. However, in this study there was an increased number of HLR Enterococcus which may be spreading intra and inter-hospital. PMID:24031416

Annual Surveillance Summary: Methicillin-Resistant Staphylococcus aureus (MRSA) Infections in the Military Health System (MHS), 2015

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2017-03-01

disproportionately affected groups without typical risk factors, such as children or young adults. 11,17,18 Within the MHS, the burden of MRSA infections in...America for the treatment of methicillin-resistant Staphylococcus aureus infectious in adults and children . Clin Infect Dis. 2011;52:1-38. 27. Lewis JS II...Accountability System SSTI skin and soft tissue infection UD unit dose UIC unit identification code US United States UTI urinary tract infection VRSA vancomycin-resistant Staphylococcus aureus

Prevalence and distribution of VRE (vancomycin resistant enterococci and VSE (vancomycin susceptible enterococci strains in the breeding environment

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Krzysztof Skowron

2016-06-01

Full Text Available [b]Introduction.[/b] Intensive animal production causes numerous problems. Facilities connected with animal maintenance not only cause environmental pollution, but also pose a great sanitary and epidemiological threat. Long-term use of antibiotics in animal production lead animal-borne microorganisms to develop multiple resistance mechanisms, transferred to the typical environmental bacteria. [b]Objective. [/b]The aim of this study was assessment of E. faecalis, E. faecium, E. durans and E. hirae prevalence in samples gathered from swine production sectors, and determination of the contribution of VRE (vancomycin resistant enterococci strains and their resistance. The degree of relationship between isolates of each species from genus Enterococcus was also determined. [b]Materials and method.[/b] 195 isolates were obtained, from which DNA was isolated. Genus identification was conducted with the primers specific to the 16S rRNA region, and identification of the species with primers specific to sequence of gene sodA in Multiplex PCR reaction. Resistance to vancomycin (6 μg×ml -1 was tested using a screening method on Muller Hinton Agar. To assess resistance type Multiplex PCR, amplifying products corresponding to genes VanA, VanB and VanC, was conducted. Genotyping was conducted using the PCR-RAPD method. [b]Results. [/b]Among the 195 isolates, 133 (68% belonged to E. hirae. The other species contributions were respectively: E. faecalis – 21%, E. durans – 8% and E. faecium – 3%. Only 2 isolates of E. hirae, being different strains, were resistant to vancomycin. Both were representing phenotype VanC1. 60 genetically different strains were defined. The possible contamination paths involved animal feed and spreading of excrements by slaughtered individuals or on personnel’s footwear. [b]Conclusions. [/b]The obtained results indicate a very low percentage of VRE strains in the tested piggery, resulting in a low health risk to piggery

Whole transcriptome analysis reveals potential novel mechanisms of low-level linezolid resistance in Enterococcus faecalis.

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Hua, Ruoyi; Xia, Yun; Wu, Wenyao; Yan, Jia; Yang, Mi

2018-03-20

Linezolid is an oxazolidinone antibiotic commonly used to treat serious infections caused by vancomycin-resistant enterococcus. Recently, low-level linezolid resistant Enterococcus faecalis strains have emerged worldwide, but the resistant mechanisms remain undefined. Whole-transcriptome profiling was performed on an E. faecalis strain P10748 with low-level linezolid resistance in comparison with a linezolid-susceptible strain 3138 and the standard control strain ATCC29212. The functions of differentially expressed genes (DEGs) were predicted, with some DEGs potentially involved in drug resistance were validated by PCR and quantitative PCR (qPCR). RNA-Seq on three E. faecalis strains generated 1920 unigenes, with 98% of them assigned to various function groups. A total of 150 DEGs were identified in the linezolid resistant strain P10748 compared to the linezolid susceptible strains 3138 and ATCC29212. Functional analysis indicated a significant transcriptomic shift to membrane transportation and biofilm formation in strain P10748, with three significantly up-regulated DEGs predicted to be associated with drug resistance through active efflux pumps and biofilm formation. The existence of these three DEGs was further confirmed by PCR and qPCR. The significant upregulation of genes associated with efflux pumps and biofilm formation in the linezolid resistant strain suggests their roles in low-level resistance to linezolid in E. faecalis. Copyright © 2018. Published by Elsevier B.V.

Efficacy of linezolid, teicoplanin, and vancomycin in prevention of an experimental polytetrafluoroethylene graft infection model caused by methicillin-resistant Staphylococcus aureus.

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Mese, Bulent; Bozoglan, Orhan; Elveren, Serdal; Eroglu, Erdinc; Gul, Mustafa; Celik, Ahmet; Ciralik, Harun; Yildirimdemir, Halil Ibrahim; Yasim, Alptekin

2015-03-27

The aim of this study was to evaluate the effectiveness of linezolid, teicoplanin, and vancomycin in prevention of prosthetic vascular graft infections in a vascular graft infection model. Fifty rats were divided into 5 groups. A polytetrafluoroethylene graft was implanted on the back of each rat. Methicillin-resistant Staphylococcus aureus (MRSA) strain was inoculated into all rats except Group 1. Group 2 was not given any treatment, Group 3 received linezolid, Group 4 received vancomycin, and Group 5 received teicoplanin. The grafts were removed for microbiological and histological examinations on the 7th day. In addition, C-reactive protein and prealbumin levels and leukocyte counts in obtained blood specimens were determined. Group 1 did not have infection. Group 2 had bacteria 5.7 × 10(4) CFU/cm(2). Group 3 and Group 4 had less bacterial growth. Group 5 had no bacterial growth. The number of bacteria was significantly higher in Group 2 than in the other experimental groups and the control group (pprevention of prosthetic vascular graft infections.

Presence of the vancomycin resistance gene cluster vanC1, vanXYc, and vanT in Enterococcus casseliflavus.

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Hölzel, Christina; Bauer, Johann; Stegherr, Eva-Maria; Schwaiger, Karin

2014-04-01

The three chromosomally located clustered genes vanC1, vanXYc, and vanT confer intrinsic resistance to vancomycin and are used for species identification of Enterococcus gallinarum. In this study, 28 strains belonging to the E. gallinarum/casseliflavus group isolated from cloacal swabs from laying hens were screened for the presence of vanC1. As confirmed by species-specific multiplex PCR, 11 vanC1-positive strains were identified as E. gallinarum. Surprisingly, one yellow pigmented strain, verified as E. casseliflavus by species-specific multiplex PCR, was also vanC1 positive; vanXYc and vanT were additionally detectable in this strain. To our knowledge, this is the first report of vanC1, vanXYc, and vanT in E. casseliflavus. The minimum inhibitory concentration of vancomycin was 4 mg/L. Real-time reverse transcription-PCR revealed that none of the clustered genes was expressed in this strain. Even if the genes seem not to be active, there is a certain risk that they will be transferred to other bacteria where they might be functionally expressed. Therefore, it may be advisable to expand the search for vanC1, vanXYc, and vanT from E. gallinarum to other (enterococcal) species. This study confirms that enterococci live up to their name as being reservoir bacteria and should therefore always be closely monitored.

Prevalence and antibiotic resistance of Enterococcus spp. isolated from retail cheese, ready-to-eat salads, ham, and raw meat.

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Pesavento, G; Calonico, C; Ducci, B; Magnanini, A; Lo Nostro, A

2014-08-01

Food specimens were analyzed in order to research Enterococcus spp.: 636 samples of raw meat (227 beef, 238 poultry, and 171 pork), 278 samples of cheese (110 fresh soft cheese and 168 mozzarella cheese), 214 samples of ready-to-eat salads, and 187 samples of ham. 312 strains of Enterococcus spp samples were isolated, then identified and submitted to susceptibility tests against 11 antimicrobial agents. The predominant species were Enterococcus faecalis in raw meat and Enterococcus faecium in retail products. Low percentages of microorganisms were resistant to vancomycin (3.53%), teicoplanin (2.24%), linezolid (0.32%), and amoxicillin in combination with clavulanic acid (0.32%). A high percentage of resistance was noted in E. faecalis at high level gentamicin (21.9%) and tetracycline (60.6%). In general, strains of E. faecalis were more resistant than E. faecium. Enterococci should be considered not only potential pathogens, but also a reservoir of genes encoding antibiotic resistance which can be transferred to other microorganisms. Continuous monitoring of their incidence and emerging resistance is important in order to identify foods which potentially represent a real risk to the population, and to ensure effective treatment of human enterococcal infections. Copyright © 2014 Elsevier Ltd. All rights reserved.

The fosfomycin resistance gene fosB3 is located on a transferable, extrachromosomal circular intermediate in clinical Enterococcus faecium isolates.

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Xiaogang Xu

Full Text Available Some VanM-type vancomycin-resistant Enterococcus faecium isolates from China are also resistant to fosfomycin. To investigate the mechanism of fosfomycin resistance in these clinical isolates, antimicrobial susceptibility testing, filter-mating, Illumina/Solexa sequencing, inverse PCR and fosfomycin resistance gene cloning were performed. Three E. faecium clinical isolates were highly resistant to fosfomycin and vancomycin with minimal inhibitory concentrations (MICs >1024 µg/ml and >256 µg/ml, respectively. The fosfomycin and vancomycin resistance of these strains could be co-transferred by conjugation. They carried a fosfomycin resistance gene fosB encoding a protein differing by one or two amino acids from FosB, which is encoded on staphylococcal plasmids. Accordingly, the gene was designated fosB3. The fosB3 gene was cloned into pMD19-T, and transformed into E. coli DH5α. The fosfomycin MIC for transformants with fosB3 was 750-fold higher than transformants without fosB3. The fosB3 gene could be transferred by an extrachromosomal circular intermediate. The results indicate that the fosB3 gene is transferable, can mediate high level fosfomycin resistance in both Gram-positive and Gram-negative bacteria, and can be located on a circular intermediate.

In vitro antimicrobial activity of linezolid tested against vancomycin-resistant enterococci isolated in Brazilian hospitals

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Reis Adriana O.

2001-01-01

Full Text Available The emergence of vancomycin-resistant enterococci (VRE has been described recently in Brazil. This is in contrast to the USA and Europe, where the VRE appeared in the late 1980s. The progressive increase in VRE isolation poses important problems in the antimicrobial therapy of nosocomial infections. Treatment options and effective antimicrobial agents for VRE are often limited and the possibility of transfer of vancomycin genes to other Gram-positive microorganisms continues. In the search for antimicrobial agents for multiresistant Gram-positive cocci, compounds such as linezolid and quinupristin/dalfopristin have been evaluated. The present study was conducted to evaluate the in vitro activity of the oxazolidinone linezolid and 10 other antimicrobial agents, including quinupristin-dalfopristin, against multiresistant enterococci isolated in Brazilian hospitals. Thirty-three vancomycin resistant isolates (17 Enterococcus faecium and 16 E. faecalis, were analyzed. Strains were isolated from patients at São Paulo Hospital, Oswaldo Cruz Hospital, Hospital do Servidor Público Estadual, Santa Marcelina Hospital, Santa Casa de Misericórdia de São Paulo, and Hospital de Clínicas do Paraná. The samples were tested by a broth microdilution method following the National Committee for Clinical Laboratory Standards (NCCLS recommendations. All isolates were molecular typed using pulsed-field gel electrophoresis (PFGE. Linezolid was the most active compound against these multiresistant enterococci, showing 100% inhibition at the susceptible breakpoints. Quinupristin/dalfopristin and teicoplanin showed poor activity against both species. The molecular typing results suggest that there has been interhospital spread of vancomycin resistant E. faecium and E. faecalis among Brazilian hospitals. The results of this study indicate that linezolid is an appropriate therapeutic option for the treatment of vancomycin-resistant enterococci infections in Brazil.

Risk factors assessment for nasal colonization of Staphylococcus aureus and its methicillin resistant strains among pre-clinical medical students of Nepal.

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Ansari, Shamshul; Gautam, Rajendra; Shrestha, Sony; Ansari, Safiur Rahman; Subedi, Shankar Nanda; Chhetri, Muni Raj

2016-04-12

Staphylococcus aureus (S. aureus), a normal flora of nasal cavity, can cause minor to life threatening invasive diseases and nosocomial infections. Methicillin resistant strains of S. aureus are causing a great challenge for treatment options. Therefore, the purpose of this study was to assess the nasal carriage rate of S. aureus, its methicillin resistant strains and risk factors in medical students prior to clinical exposure. The bacterial growth of S. aureus from nasal swab culture was identified by using standard microbiological methods recommended by American Society for Microbiology. Modified Kirby-Bauer disk diffusion method was used for antibiotic susceptibility testing and methicillin resistance was confirmed using cefoxitin and oxacillin disks. D-zone test method was used to determine the inducible clindamycin resistance. Among 200 participants, nasal carriage of S. aureus was detected from 30 (15%) subjects. Upper respiratory tract infections significantly (P aureus and their methicillin resistant strains. All of the isolates were reported to be susceptible to vancomycin and teicoplanin. S. aureus strains detected from 8 (4%) students were confirmed to be methicillin resistant. The result of our study demands for strict policy to screen all the students for nasal carriage of S. aureus and its MRSA strains to minimize the transmission of this organism from community to hospital settings.

Prevalence and determinants of fecal colonization with vancomycin-resistant Enterococcus in hospitalized patients in The Netherlands

NARCIS (Netherlands)

van den Braak, N.; Ott, A.; van Belkum, A.; Kluytmans, J. A.; Koeleman, J. G.; Spanjaard, L.; Voss, A.; Weersink, A. J.; Vandenbroucke-Grauls, C. M.; Buiting, A. G.; Verbrugh, H. A.; Endtz, H. P.

2000-01-01

To determine the prevalence and determinants of fecal carriage of vancomycin-resistant enterococci (VRE) in intensive care unit (ICU), hematology-oncology, and hemodialysis patients in The Netherlands. Descriptive, multicenter study, with yearly 1-week point-prevalence assessments between 1995 and

Subinhibitory concentrations of imipenem induce increased resistance to methicillin and imipenem in vitro in methicillin-resistant Staphylococcus aureus.

OpenAIRE

Forbes, B A; McClatchey, K D; Schaberg, D R

1984-01-01

Methicillin-resistant (MR) Staphylococcus aureus that was susceptible to less than 0.75 micrograms of imipenem per ml demonstrated inducible resistance. MR S. aureus preincubated with 0.05 microgram of imipenem per ml grew in medium with an imipenem concentration of 32 micrograms/ml, and methicillin MICs increased 20-fold. Non-MR S. aureus exhibited no induction. Preincubation with methicillin produced no effect. Induction appeared to be a unique interaction of imipenem with MR S. aureus.

Heterogeneous vancomycin-intermediate susceptibility in a community-associated methicillin-resistant Staphylococcus aureus epidemic clone, in a case of Infective Endocarditis in Argentina

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Vindel Ana

2011-04-01

Full Text Available Abstract Background Community-Associated Methicillin Resistant Staphylococcus aureus (CA-MRSA has traditionally been related to skin and soft tissue infections in healthy young patients. However, it has now emerged as responsible for severe infections worldwide, for which vancomycin is one of the mainstays of treatment. Infective endocarditis (IE due to CA-MRSA with heterogeneous vancomycin-intermediate susceptibility-(h-VISA has been recently reported, associated to an epidemic USA 300 CA-MRSA clone. Case Presentation We describe the occurrence of h-VISA phenotype in a case of IE caused by a strain belonging to an epidemic CA-MRSA clone, distinct from USA300, for the first time in Argentina. The isolate h-VISA (SaB2 was recovered from a patient with persistent bacteraemia after a 7-day therapy with vancomycin, which evolved to fatal case of IE complicated with brain abscesses. The initial isolate-(SaB1 was fully vancomycin susceptible (VSSA. Although MRSA SaB2 was vancomycin susceptible (≤2 μg/ml by MIC (agar and broth dilution, E-test and VITEK 2, a slight increase of MIC values between SaB1 and SaB2 isolates was detected by the four MIC methods, particularly for teicoplanin. Moreover, Sab2 was classified as h-VISA by three different screening methods [MHA5T-screening agar, Macromethod-E-test-(MET and by GRD E-test] and confirmed by population analysis profile-(PAP. In addition, a significant increase in cell-wall thickness was revealed for SaB2 by electron microscopy. Molecular typing showed that both strains, SaB1 and SaB2, belonged to ST5 lineage, carried SCCmecIV, lacked Panton-Valentine leukocidin-(PVL genes and had indistinguishable PFGE patterns (subtype I2, thereby confirming their isogenic nature. In addition, they were clonally related to the epidemic CA-MRSA clone (pulsotype I detected in our country. Conclusions This report demonstrates the ability of this epidemic CA-MRSA clone, disseminated in some regions of Argentina, to

An investigation of vancomycin minimum inhibitory concentration creep among methicillin-resistant Staphylococcus aureus strains isolated from pediatric patients and healthy children in Northern Taiwan.

Science.gov (United States)

Chang, Chia-Ning; Lo, Wen-Tsung; Chan, Ming-Chin; Yu, Ching-Mei; Wang, Chih-Chien

2017-06-01

The phenomenon of vancomycin minimum inhibitory concentration (MIC) creep is an increasingly serious problem in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. In this study, we investigated the vancomycin and daptomycin MIC values of MRSA strains isolated from pediatric patients and MRSA colonized healthy children. Then, we assessed whether there was evidence of clonal dissemination for strains with an MIC to vancomycin of ≥ 1.5 μg/mL. We collected clinical MRSA isolates from pediatric patients and from healthy children colonized with MRSA during 2008-2012 at a tertiary medical center in northern Taiwan and obtained vancomycin and daptomycin MIC values using the Etest method. Pulse-field gel electrophoresis (PFGE) and staphylococcal cassette chromosome (SCCmec) typing were used to assess clonal dissemination for strains with an MIC to vancomycin of ≥ 1.5 μg/mL. A total 195 MRSA strains were included in this study; 87 were isolated patients with a clinical MRSA infection, and the other 108 strains from nasally colonized healthy children. Vancomycin MIC≥1.5 μg/mL was seen in more clinical isolates (60/87, 69%) than colonized isolates (32/108, 29.6%), p < 0.001. The PFGE typing of both strains revealed multiple pulsotypes. Vancomycin MIC creeps existed in both clinical MRSA isolates and colonized MRSA strains. Great diversity of PFGE typing was in both strains collected. There was no association between the clinical and colonized MRSA isolates with vancomycin MIC creep. Copyright © 2016. Published by Elsevier B.V.

An economic model to compare linezolid and vancomycin for the treatment of confirmed methicillin-resistant Staphylococcus aureus nosocomial pneumonia in Germany

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Patel DA

2014-10-01

Full Text Available Dipen A Patel,1 Andre Michel,2 Jennifer Stephens,1 Bertram Weber,3 Christian Petrik,4 Claudie Charbonneau5 1Health Economic and Outcomes Research, Pharmerit International, Bethesda, MD, USA; 2Klinikum Hanau GmbH, Hanau, Germany; 3Health Technology Assessment and Outcomes Research, 4Anti-infectives, Pfizer, Berlin, Germany; 5Pfizer International Operations, Pfizer France, Paris, France Background: Across Europe, methicillin-resistant Staphylococcus aureus (MRSA is considered to be the primary cause of nosocomial pneumonia (NP. In Germany alone, approximately 14,000 cases of MRSA-associated NP occur annually, which may have a significant impact on health care resource use and associated economic costs. The objective of this study was to investigate the economic impact of linezolid compared with that of vancomycin in the treatment of hospitalized patients with MRSA-confirmed NP in the German health care system. Methods: A 4-week decision tree model incorporated published data and expert opinion on clinical parameters, resource use, and costs (2012 euros was constructed. The base case first-line treatment duration for patients with MRSA-confirmed NP was 10 days. Treatment success (survival, failure due to lack of efficacy, serious adverse events, and mortality were possible outcomes that could impact costs. Alternate scenarios were analyzed, such as varying treatment duration (7 or 14 days or treatment switch due to a serious adverse event/treatment failure (at day 5 or 10. Results: The model calculated total base case inpatient costs of €15,116 for linezolid and €15,239 for vancomycin. The incremental cost-effectiveness ratio favored linezolid (versus vancomycin, with marginally lower costs (by €123 and greater efficacy (+2.7% absolute difference in the proportion of patients successfully treated for MRSA NP. Approximately 85%–87% of the total treatment costs were attributed to hospital stay (primarily in the intensive care unit

Characterization and modelling of VanT: a novel, membrane-bound, serine racemase from vancomycin-resistant Enterococcus gallinarum BM4174.

Science.gov (United States)

Arias, C A; Martín-Martinez, M; Blundell, T L; Arthur, M; Courvalin, P; Reynolds, P E

1999-03-01

Sequence determination of a region downstream from the vanXYc gene in Enterococcus gallinarum BM4174 revealed an open reading frame, designated vanT, that encodes a 698-amino-acid polypeptide with an amino-terminal domain containing 10 predicted transmembrane segments. The protein contained a highly conserved pyridoxal phosphate attachment site in the C-terminal domain, typical of alanine racemases. The protein was overexpressed in Escherichia coli, and serine racemase activity was detected in the membrane but not in the cytoplasmic fraction after centrifugation of sonicated cells, whereas alanine racemase activity was located almost exclusively in the cytoplasm. When the protein was overexpressed as a polypeptide lacking the predicted transmembrane domain, serine racemase activity was detected in the cytoplasm. The serine racemase activity was partially (64%) inhibited by D-cycloserine, whereas host alanine racemase activity was almost totally inhibited (97%). Serine racemase activity was also detected in membrane preparations of constitutively vancomycin-resistant E. gallinarum BM4174 but not in BM4175, in which insertional inactivation of the vanC-1 D-Ala:D-Ser ligase gene probably had a polar effect on expression of the vanXYc and vanT genes. Comparative modelling of the deduced C-terminal domain was based on the alignment of VanT with the Air alanine racemase from Bacillus stearothermophilus. The model revealed that almost all critical amino acids in the active site of Air were conserved in VanT, indicating that the C-terminal domain of VanT is likely to adopt a three-dimensional structure similar to that of Air and that the protein could exist as a dimer. These results indicate that the source of D-serine for peptidoglycan synthesis in vancomycin-resistant enterococci expressing the VanC phenotype involves racemization of L- to D-serine by a membrane-bound serine racemase.

Methicillin-resistant Staphylococcus aureus in palliative care: A prospective study of Methicillin-resistant Staphylococcus aureus prevalence in a hospital-based palliative care unit.

Science.gov (United States)

Schmalz, Oliver; Strapatsas, Tobias; Alefelder, Christof; Grebe, Scott Oliver

2016-07-01

Methicillin-resistant Staphylococcus aureus is a common organism in hospitals worldwide and is associated with morbidity and mortality. However, little is known about the prevalence in palliative care patients. Furthermore, there is no standardized screening protocol or treatment for patients for whom therapy concentrates on symptom control. Examining the prevalence of methicillin-resistant Staphylococcus aureus in palliative care patients as well as the level of morbidity and mortality. We performed a prospective study where methicillin-resistant Staphylococcus aureus screening was undertaken in 296 consecutive patients within 48 h after admission to our palliative care unit. Medical history was taken, clinical examination was performed, and the Karnofsky Performance Scale and Palliative Prognostic Score were determined. Prevalence of Methicillin-resistant Staphylococcus aureus was compared to data of general hospital patients. In total, 281 patients were included in the study having a mean age of 69.7 years (standard deviation = 12.9 years) and an average Karnofsky Performance Scale between 30% and 40%. The mean length of stay was 9.7 days (standard deviation = 7.6 days). A total of 24 patients were methicillin-resistant Staphylococcus aureus positive on the first swab. Median number of swabs was 2. All patients with a negative methicillin-resistant Staphylococcus aureus swab upon admission remained Methicillin-resistant Staphylococcus aureus negative in all subsequent swabs. Our study suggests that the prevalence of Methicillin-resistant Staphylococcus aureus among patients in an in-hospital palliative care unit is much higher than in other patient populations. © The Author(s) 2016.

Structural and Functional Adaptation of Vancomycin Resistance VanT Serine Racemases.

Science.gov (United States)

Meziane-Cherif, Djalal; Stogios, Peter J; Evdokimova, Elena; Egorova, Olga; Savchenko, Alexei; Courvalin, Patrice

2015-08-11

Vancomycin resistance in Gram-positive bacteria results from the replacement of the D-alanyl-D-alanine target of peptidoglycan precursors with D-alanyl-D-lactate or D-alanyl-D-serine (D-Ala-D-Ser), to which vancomycin has low binding affinity. VanT is one of the proteins required for the production of D-Ala-D-Ser-terminating precursors by converting L-Ser to D-Ser. VanT is composed of two domains, an N-terminal membrane-bound domain, likely involved in L-Ser uptake, and a C-terminal cytoplasmic catalytic domain which is related to bacterial alanine racemases. To gain insight into the molecular function of VanT, the crystal structure of the catalytic domain of VanTG from VanG-type resistant Enterococcus faecalis BM4518 was determined. The structure showed significant similarity to type III pyridoxal 5'-phosphate (PLP)-dependent alanine racemases, which are essential for peptidoglycan synthesis. Comparative structural analysis between VanTG and alanine racemases as well as site-directed mutagenesis identified three specific active site positions centered around Asn696 which are responsible for the L-amino acid specificity. This analysis also suggested that VanT racemases evolved from regular alanine racemases by acquiring additional selectivity toward serine while preserving that for alanine. The 4-fold-lower relative catalytic efficiency of VanTG against L-Ser versus L-Ala implied that this enzyme relies on its membrane-bound domain for L-Ser transport to increase the overall rate of d-Ser production. These findings illustrate how vancomycin pressure selected for molecular adaptation of a housekeeping enzyme to a bifunctional enzyme to allow for peptidoglycan remodeling, a strategy increasingly observed in antibiotic-resistant bacteria. Vancomycin is one of the drugs of last resort against Gram-positive antibiotic-resistant pathogens. However, bacteria have evolved a sophisticated mechanism which remodels the drug target, the D-alanine ending precursors in cell wall

Tabebuia avellanedae naphthoquinones: activity against methicillin-resistant staphylococcal strains, cytotoxic activity and in vivo dermal irritability analysis

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Giambiagi-deMarval Marcia

2006-03-01

Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA and coagulase-negative staphylococcus infections are a worldwide concern. Currently, these isolates have also shown resistance to vancomycin, the last therapy used in these cases. It has been observed that quinones and other related compounds exhibit antibacterial activity. This study evaluated the antibacterial activity, toxicity and in vivo dermal irritability of lapachol extracted from Tabebuia avellanedae and derivatives against methicillin-resistant staphylococcal isolates. In addition, its mechanism of action was also analyzed. Methods The compounds β-lapachone, 3-hydroxy β N lapachone and α-lapachone were tested to determine the MIC values against methicillin-resistant S. aureus, S. epidermidis and S. haemolyticus strains, being the two last ones hetero-resistant to vancomycin. Experiments of protein synthesis analysis to investigate the naphthoquinones action were assessed. In vitro toxicity to eukaryotic BSC-40 African Green Monkey Kidney cell cultures and in vivo primary dermal irritability in healthy rabbits were also performed. Results The compounds tested showed antibacterial activity (MICs of 8, 4/8 and 64/128 μg/mL to β-lapachone, 3-hydroxy β N lapachone and α-lapachone, respectively, but no bactericidal activity was observed (MBC > 512 μg/mL for all compounds. Although it has been observed toxic effect in eukaryotic cells, the compounds were shown to be atoxic when applied as topic preparations in healthy rabbits. No inhibition of proteins synthesis was observed. Conclusion Our results suggest that quinones could be used in topic preparations against wound infections caused by staphylococci, after major investigation of the pharmacological properties of the compounds. Studies about the use of these compounds on tumoral cells could be carried on, due to their effect in eukaryotic cells metabolism.

Active surveillance for asymptomatic colonisation by multidrug-resistant bacteria in patients transferred to a tertiary care hospital in the occupied Palestinian territory.

Science.gov (United States)

Taha, Adham Abu; Daoud, Ayman; Zaid, Sawsan; Sammour, Sajida; Belleh, Maram; Daifi, Refqa

2018-02-21

Active surveillance is important in infection control programmes, allowing the detection of patients colonised with multi-drug resistant organisms and preventing the spread of multi-drug resistant organisms. The aim of this study was to determine the rate of asymptomatic colonisation with multi-drug resistant organisms and the prevalence of each organism in patients transferred to An-Najah National University Hospital, Nablus, occupied Palestinian territory. Patients transferred from other hospitals between January and December, 2015, were screened at time of admission by taking nasal, groin, and axillary swabs. Swabs were cultured and assessed for the presence of multi-drug resistant organisms (extended spectrum β-lactamase producers, Pseudomonas aeroginosae, Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococcus, and carbapenem-resistant enterobacteriaceae. Of the 822 screened patients, 265 (32%) had infections with multi-drug resistant organisms. 394 isolates of multi-drug resistant organisms were obtained: 131 (33%) isolates were extended spectrum β-lactamase producers, 119 (30%) isolates were P aeroginosae, 26 (9%) isolates were A baumannii, 94 (24%) isolates were methicillin-resistant S aureus, 13 (3%) isolates were vancomycin-resistant enterococci, and one (<1%) isolate was carbapenem-resistant enterobacteriaceae. We identified a high prevalence of asymptomatic colonisation with multidrug-resistant bacteria in transferred patients. These findings emphasise the need for a national strategy to combat the spread of multi-drug resistant organisms in the occupied Palestinian territory. An-Najah National University. Copyright © 2018 Elsevier Ltd. All rights reserved.

Molecular mechanisms of methicillin resistance in Staphylococcus aureus.

Science.gov (United States)

Domínguez, M A; Liñares, J; Martín, R

1997-09-01

Methicillin-resistant Staphylococcus aureus (MRSA) strains are among the most common nosocomial pathogens. The most significant mechanism of resistance to methicillin in this-species is the acquisition of a genetic determinant (mecA gene). However, resistance seems to have a more complex molecular basis, since additional chromosomal material is involved in such resistance. Besides, overproduction of penicillinase and/or alterations in the PBPs can contribute to the formation of resistance phenotypes. Genetic and environmental factors leading to MRSA are reviewed.

Prevalence and antibiotic-resistance characteristics of Enterococcus spp. Isolated from free-living and captive raptors in Central Illinois.

Science.gov (United States)

Marrow, Judilee; Whittington, Julia K; Mitchell, Mark; Hoyer, Lois L; Maddox, Carol

2009-04-01

Due to their predatory nature, raptor species may serve as important indicators of environmental contamination with antimicrobial-resistant bacteria. Raptors prey on small rodents and birds that have diverse habitat ranges, including urban and rural environments, and their intestinal microflora can reflect that of the animals on which they feed. Enterococcus spp. were selected as target organisms because they have been isolated from the avian gastrointestinal tract, can be conferred by prey items, and because they are capable of multiple resistance patterns. They are also a concerning source of human antimicrobial resistance. In this study fecal cultures were obtained from 15 May 2004 to 31 August 2004, from 21 free-living raptors and four captive raptors. Enterococcus was isolated from 21 (84%) of the 25 birds, and 54 isolates were chosen for further study based upon unique colony morphology. The most common isolate recovered was Enterococcus faecalis (95%, 95% confidence interval [CI]: 89-100). One bird in the study was determined to have Enterococcus gallinarum. Two distinct ribotypes of E. faecalis were identified, one with unique bands at 11 and 13 kb and the other with unique bands at 14 and 20 kb. Both ribotypes were found in free-living and captive birds. The Enterococcus isolates in this study demonstrated a variety of antimicrobial-resistance characteristics, including almost complete resistance to amikacin, first-generation cephalosporins, spectinomycin, and sulphadimethoxime. Isolates demonstrated variable resistance to chloramphenicol, gentamicin, enrofloxacin, erythromycin, and ticarcillin. No phenotypically vancomycin-resistant E. faecalis isolates were recovered from any of the raptors; three isolates had intermediate level susceptibility. A significantly higher number of isolates collected from captive birds demonstrated resistance to chloramphenicol than those obtained from free-living birds. This trend was not duplicated with any of the remaining

Determination of antimicrobial resistance to extended-spectrum cephalosporin, quinolones, and vancomycin in selected human enteric pathogens from Prince Edward Island, Canada.

Science.gov (United States)

Awosile, Babafela; German, Gregory; Rodriguez-Lecompte, Juan Carlos; Saab, Matthew E; Heider, Luke C; McClure, J Trenton

2018-04-05

The aim of this study was to determine the frequency of fecal carriage of vancomycin-resistant Enterococcus spp. and Escherichia coli with reduced susceptibilities to extended-spectrum cephalosporins (ESCs) and quinolones in humans on Prince Edward Island, Canada. Convenience fecal samples from individuals on Prince Edward Island were screened phenotypically using selective culture and genotypically using multiplex polymerase chain reactions to detect E. coli and Enterococcus spp. resistant to critically important antimicrobials. Twenty-six (5.3%) of 489 individuals had E. coli with reduced susceptibility to ESCs. Twenty-five (96.2%) of the 26 isolates harbored bla TEM , 18 (69.2%) harbored bla CMY-2 , 16 (61.5%) harbored bla CTX-M groups, 2 (7.7%) harbored bla SHV genes. None of the ESC-resistant E. coli was positive for carbapenem resistance. Twenty-one (8.3%) of 253 individuals had E. coli isolates with reduced quinolone susceptibility. All 21 isolates were positive for at least 1 qnr gene, with 3 (14.3%) isolates positive for qnrB, 5 (23.8%) positive for qnrS, and 13 (61.9%) positive for both qnrB and qnrS genes. All the enterococci isolates were vancomycin-susceptible. Higher susceptibility to the critically important antimicrobials was found in this study. This study can serve as a baseline for future antimicrobial resistance surveillance within this region.

METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS (MRSA ...

African Journals Online (AJOL)

Nosocomial infections caused by methicillin-resistant strains of Staphylococcus aureus often pose therapeutic dilemma to the clinicians because of the multi resistant nature of these strains of Staphylococcus aureus. Outbreaks of both nosocomial and community acquired infections are also frequent and difficult to control.

Recovery of vancomycin-resistant gram-positive cocci from children.

Science.gov (United States)

Green, M; Wadowsky, R M; Barbadora, K

1990-03-01

A cross-sectional survey of vancomycin-resistant gram-positive cocci (VRGPC) in the feces of children was initiated after several bacteremic infections with these organisms occurred at our hospital. A selective medium consisting of colistin-nalidixic acid agar, 5% sheep blood, vancomycin (5 mg/liter), and amphotericin B (8 mg/liter) was developed to isolate VRGPC. A single stool specimen submitted to the clinical microbiology laboratory from each of 48 patients was inoculated onto the medium. Plates were incubated at 35 degrees C with 5% carbon dioxide and examined at 24, 48, and 72 h. Susceptibilities were determined by broth microdilution. A total of 14 isolates from 11 of 48 (22%) children were recovered. The density of growth ranged from a single colony to 2+. The VRGPC were identified as Leuconostoc lactis (n = 2), Lactobacillus confusus (n = 4), Enterococcus species (n = 5), and Lactococcus lactis (n = 3). One strain of Lactobacillus confusus was recovered from both the stool and the blood of one of these patients. The MICs of vancomycin were 4 micrograms/ml for one of the isolates, 8 micrograms/ml for four of the isolates, and more than 16 micrograms/ml for the remaining eight isolates. All isolates were susceptible to both penicillin and ampicillin. Only 1 of the 11 children had received prior treatment with vancomycin. We conclude that low concentrations of VRGPC may be common in the gastrointestinal tracts of children.

Infecção ou colonização por micro-organismos resistentes: identificação de preditores Infection or colonization with resistant microorganisms: identification of predictors

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Graciana Maria de Moraes

2013-01-01

Full Text Available OBJETIVO: Identificar os fatores preditores de infecção ou colonização por micro-organismos resistentes. MÉTODOS: Foi realizado estudo quantitativo de coorte prospectivo. Foram realizadas a análise descritiva, para conhecimento da população do estudo, e a análise discriminante, para identificação dos fatores preditores. RESULTADOS: Foram incluídos 85 pacientes com infecções por micro-organismos resistentes: Pseudomonas aeruginosas resistente aos carbapenêmicos (24,7%, Acinetobacter resistente aos carbapenêmicos (21,2%, Staphylococcus aureus resistente à meticilina (25,9%, Enterococcus spp. resistente à vancomicina (17,6% e Klebsiella pneumoniae resistente aos carbapenêmicos (10,6%. A análise discriminante identificou transferências de outros hospitais e internação na Unidade de Terapia Intensiva como fatores preditores para ocorrência de infecção pelos grupos S. aureus resistente à meticilina, Acinetobacter resistente aos carbapenêmicos e K. pneumoniae resistente aos carbapenêmicos. Nenhuma das variáveis estudadas foi discriminante para Enterococcus spp. resistente à vancomicina e P. aeruginosas resistente aos carbapenêmico. CONCLUSÃO: Os fatores preditores encontrados foram: internação na UTI e a transferências de outros hospitais.OBJECTIVE: Identifying predictors of infection or colonization with resistant microorganisms. METHODS: A quantitative study of prospective cohort was carried out. A descriptive analysis was performed in order to know the population of the study and a discriminant analysis was performed to identify the predictors. RESULTS: In this study were included 85 patients with infections caused by resistant microorganisms: carbapenem-resistant Pseudomonas aeruginosas (24.7%; carbapenem-resistant Acinetobacter (21.2%; methicillin-resistant Staphylococcus aureus (25.9%, vancomycin-resistant Enterococcus spp (17.6% and carbapenem-resistant Klebsiella pneumonia (10.6%. The discriminant analysis

Prevalence study of enterococus and staphylococci resistance to vancomycin isolated from urinary tract infections

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Mohammad Kazem Sharifi Yazdi

2013-07-01

Full Text Available Background: The role of gram-positive cocci especially Staphylococci species in causing urinary tract infection are well known. Among the Staphylococci species Methicillin Resistance Staphylococcus aureus (MRSA is the most important. The rate of MRSA is increasing worldwide. This is alarming because the danger of these organism in public health. Therefore the aim of this study was to determine the sensitivity of gram-positive cocci, as well as MRSA to vancomycin and other antibiotics.Methods: This was a descriptive study, and were carried out on 300 patients with urinary tract infections (UTI caused by gram-positive cocci, referred to Imam Khomeini hospital during eight months. Prior to the antibiotic sensitivity testing all the isolates were identified according to the standard conventional biochemical procedure, and then the antibiotic susceptibility test were carried out according to Bauer-Kirby method. Results: Among the gram positive cocci causing UTI, the most abundant were Staphylococcus saprophyticus (37.7%, followed by Staphylococcus epidermidis (22.3% and Staphylococcus aureus (18% respectivley. The sex distribution of patients were 163 female (54.3% and 137 male (45.7% respectively, and the prevalence rate of urinary tract infections in female was (8.6% higher than male. The rate of sensitivity of isolated Staphylococci were as followed, sensitive to vancomycine (100%, Ciprofloxacin (89.2%, rifampin (87.6%, and amikacin (71.8% respectivley, but were resistant to penicillin and amoxicillin (100%. The antibiotic sensitivity rate of isolated  Streptococci was to vancomycine (85.1%, ciprofloxacin (50.7% and penicillin (79.1% respectively.Conclusion: Vancomycin is still a suitable antibiotic for the treatment of Staphyloco-ccus infections. Although 6% rate of enterococci resistance to vancomycin is alarming, and use of this antibiotic in the treatment of other gram-positive bacteria should be done with precaution.

METHICILLIN RESISTANCE IN STAPHYLOCOCCAL ISOLATES ...

African Journals Online (AJOL)

The study assessed the importance of Staphylococcus aureus as a urinary pathogen and the incidence of multidrug resistant (MDR), methicillin-resistant Staphylococcus aureus (MRSA). A total of 86 staphylococcal isolates made up of 50 clinical isolates from urine samples submitted to the Medical Microbiology Laboratory ...

Molecular Identification of Methicillin-Resistant Staphylococcus ...

African Journals Online (AJOL)

Antimicrobial resistance has become a great public health problem worldwide and multi-drug resistant Staphylococcus aureus has been widely reported. Methods: The presence or absence of methicillin resistance gene (mecA) in 48 clinical wound isolates of S. aureus was examined by the polymerase chain reaction ...

Antimicrobial susceptibility pattern and SCCmec types of methicillin-resistant coagulase-negative staphylococci from subclinical bovine mastitis in Hatay, Turkey

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Aslantaş Özkan

2014-12-01

Full Text Available Eighty-nine isolates of coagulase-negative staphylococci (CoNS of eight species from subclinical bovine mastitis were screened for the phenotypic and genotypic methicilline-resistance. In addition, all methicillin-resistant (MR isolates indicating the mecA gene were examined by PCR for the antimicrobial susceptibility patterns, and staphylococcal cassette chromosome mec (SCCmec types were also determined by multiplex PCR. A total of 21 (23.6% CoNS isolates were found to be resistant to oxacillin in broth microdilution assay. All isolates phenotypically resistant to oxacillin did not have the mecA gene, which was only found in 14.6% (13 of the isolates. Most MR-CoNS isolates were highly resistant to erythromycin (92.3%, fusidic acid (84.6%, penicillin (76.9%, and rifampycin (61.5%, and susceptible to mupirocin (100%, tetracycline (100%, vancomycin (100%, clindamycin (92.3%, and sulfamethoxazole-trimethoprim (69.2%. In conclusion, a high rate of antimicrobial resistance among MR-CoNS isolated from food producing animals emphasises the need for periodic surveillance of their resistance.

Iterative Chemical Engineering of Vancomycin Leads to Novel Vancomycin Analogs With a High in Vitro Therapeutic Index

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Nigam M. Mishra

2018-06-01

Full Text Available Vancomycin is a glycopeptide antibiotic that inhibits transpeptidation during cell wall synthesis by binding to the D-Ala-D-Ala termini of lipid II. For long, it has been used as a last resort antibiotic. However, since the emergence of the first vancomycin-resistant enterococci in 1987, vancomycin resistance has become widespread, especially in hospitals. We have synthesized and evaluated 110 vancomycin analogs modified at the C-terminal carboxyl group of the heptapeptide moiety with R2NHR1NH2 substituents. Through iterative optimizations of the substituents, we identified vancomycin analogs that fully restore (or even exceed the original inhibitory activity against vancomycin-resistant enterococci (VRE, vancomycin-intermediate (VISA and vancomycin-resistant Staphylococcus aureus (VRSA strains. The best analogs have improved growth inhibitory activity and in vitro therapeutic indices against a broad set of VRE and methicillin-resistant S. aureus (MRSA isolates. They also exceed the activity of vancomycin against Clostridium difficile ribotypes. Vanc-39 and Vanc-42 have a low probability to provoke antibiotic resistance, and overcome different vancomycin resistance mechanisms (VanA, VanB, and VanC1.

Effect of methylglyoxal on multidrug-resistant Pseudomonas aeruginosa

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Katsuhiko eHayashi

2014-04-01

Full Text Available Honey has a complex chemistry, and its broad-spectrum antimicrobial activity varies with floral source, climate, and harvesting conditions. Methylglyoxal was identified as the dominant antibacterial component of manuka honey. Although it has been known that methylglyoxal has antibacterial activity against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus, there is not much information describing its activity against gram-negative bacteria. In this study, we report the effect of methylglyoxal against multidrug-resistant Pseudomonas aeruginosa (MDRP using 53 clinically isolated strains. We also assessed the effect of deleting the five multidrug efflux systems in P. aeruginosa, as well as the efflux systems in Escherichia coli and Salmonella enterica serovar Typhimurium, on MICs of methylglyoxal. Our results indicate that methylglyoxal inhibits the growth of MDRP at concentrations of 128–512 µg/ml (1.7–7.1 mM and is not recognized by drug efflux systems.

Study on the susceptibility of Enterococcus faecalis from infectious processes to ciprofloxacin and vancomycin

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A. Genaro

2005-09-01

Full Text Available Enterococcus faecalis is considered a pathogen responsible for hospital infections and, due to its frequent multi-resistant profile, has caused preoccupations among many medical authorities. The objective of this study was to determine the antimicrobial susceptibility of 74 strains isolated from blood cultures and purulent secretions to vancomycin and ciprofloxacin through the Minimum Inhibitory Concentration (MIC and Minimum Bactericidal Concentration (MBC by using the Microdilution test. The results showed a greater efficacy of vancomycin compared to ciprofloxacin (98.6% of the strains were inhibited by vancomycin at lower concentrations: 0.06 - 1 µg/ml. However, in the MBC analysis 73% of the strains showed a MBC of vancomycin only at high concentrations (equal to or higher than 64 µg/ml. For ciprofloxacin, the strains showed a broad sensitivity with MICs and MBCs distributed along all the MIC classes. Results also revealed a probability that some strains are tolerant to vancomycin, which indicates the need of other tests to confirm this characteristic.

A comparison of antimicrobial resistance rates in Gram-positive pathogens isolated in the UK from October 1996 to January 1997 and October 1997 to January 1998.

Science.gov (United States)

Andrews, J; Ashby, J; Jevons, G; Marshall, T; Lines, N; Wise, R

2000-03-01

Rates of resistance for two consecutive years for 28 centres (10 Teaching, nine Associate Teaching and nine District General hospitals) in the UK were compared. Combined rates of resistance for each of the hospital types of Staphylococcus aureus to methicillin revealed an increase in the rate of resistance in Teaching hospitals (12.5% year 1, 23.5% year 2), but, for Associate Teaching and District General hospitals rates fell (Associate Teaching 19.1% year 1, 11.9% year 2; District General 16.5% year 1 and 11.3% year 2). Using conventional methodology to determine MICs, no strain was considered to have reduced susceptibility to vancomycin. Among coagulase-negative staphylococci, increased resistance was observed for Staphylococcus epidermidis to rifampicin, for Staphylococcus haemolyticus to clindamycin, for Staphylococcus saprophyticus to penicillin and for Staphylococcus spp. to clindamycin, methicillin and rifampicin. For Streptococcus pneumoniae an upward trend in low-level resistance to penicillin was observed (18 of the 28 centres), however, for high-level resistance the trend was in the opposite direction (only four centres showed an increase). For Enterococcus faecalis there was a trend to a fall in levels of resistance, the only exception being an increase in high-level gentamicin resistance (10.5% year 1, 15.1% year 2, P = 0.0388). For Enterococcus faecium rates of resistance were not significantly different except for increases in resistance to nitrofurantoin and rifampicin.

Vancomycin-resistant Enterococcus faecium bacteraemia as a complication of Kayexalate (sodium polystyrene sulfonate, SPS) in sorbitol-induced ischaemic colitis.

Science.gov (United States)

Cerrud-Rodriguez, Roberto Christian; Alcaraz-Alvarez, Diego; Chiong, Brian Bobby; Ahmed, Abdurhman

2017-11-09

We present the case report of an 80-year-old woman with chronic kidney disease stage G5 admitted to the hospital with fluid overload and hyperkalaemia. Sodium polystyrene sulfonate (SPS, Kayexalate) in sorbitol suspension was given orally to treat her hyperkalaemia, which precipitated an episode of SPS in sorbitol-induced ischaemic colitis with the subsequent complication of vancomycin-resistant Enterococcus (VRE) bacteraemia. SPS (Kayexalate) in sorbitol suspension has been implicated in the development of intestinal necrosis. Sorbitol, which is added as a cathartic agent to decrease the chance of faecal impaction, may be primarily responsible through several proposed mechanisms. The gold standard of diagnosis is the presence of SPS crystals in the colon biopsy. On a MEDLINE search, no previous reports of a VRE bacteraemia as a complication of biopsy-confirmed SPS in sorbitol ischaemic colitis were found. To the best of our knowledge, ours would be the first such case ever reported. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Resistência antimicrobiana em Enterococcus faecalis e Enterococcus faecium isolados de carcaças de frango

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Ana Claudia F. Borges de Campos

2013-05-01

Full Text Available O objetivo deste trabalho foi realizar o isolamento e analisar o perfil de resistência antimicrobiana de Enterococcus de carcaças de frango resfriadas e congeladas comercializadas no Distrito Federal, detectando genes de resistência antimicrobiana e identificando as espécies Enterococcus faecalis e Enterococcus faecium por reação polimerase em cadeia. Foram analisadas 100 carcaças de frangos, das quais foram isoladas 50 cepas de Enterococcus spp., sendo 42% de E. faecalis e 2% de E. faecium. O teste de susceptibilidade antimicrobiana demonstrou que todas as cepas isoladas apresentaram resistência a pelo menos um antimicrobiano, dos quais 90,47% das cepas de E. faecalis, 100% das cepas de E. Faecium e 82,14% dos Enterococcus spp. apresentaram resistência à Tetraciclina; 80,95% das cepas de E. faecalis e 35,71% das cepas de Enterococcus spp. foram resistentes à Eritromicina; 39,28% dos Enterococcus spp. e 23,80% dos E. faecalis à Ciprofloxacina e 28,57% dos E. faecalis apresentaram resistência ao Cloranfenicol. Foram detectados os genes de resistência antimicrobiana erm(B, vanC-1, aph(3'-llla, ant(6-la, vanB, vanA, aac(6'-le-aph(2''-la, erm(A e tet(M - este último mais frequente. Estes resultados sugerem sérios problemas para a Saúde Pública, uma vez que esses microrganismos podem possuir a capacidade de transmitir genes de resistência antimicrobiana para outros microrganismos presentes na microbiota intestinal de humanos e animais, podendo inviabilizar o uso destas drogas para tratamentos clínicos.

Nasal and hand carriage rate of methicillin resistant Staphylococcus aureus (MRSA) among health care workers in Mekelle Hospital, North Ethiopia.

Science.gov (United States)

Gebreyesus, Araya; Gebre-Selassie, Solomon; Mihert, Adane

2013-01-01

Methicillin resistant Staphylococcus aureus (MRSA) is significant major pathogen responsible for hospital and community based infections. The aim of this study was to assess the nasal and hand carriage of methicillin resistant Staphylococcus aureus in health care workers of Mekelle Hospital The study was carried out during November 2010 to January 2011. Swab samples from both anterior nares and hands were taken. The samples were cultured on mannitol salt agar and incubated aerobically at 37 degrees C for 48 hours. Staphylococcus aureus was identified as nmannitol fermenter and coagulase test positive. Antimicrobial susceptibility test for MRSA was done by disk diffusion method using oxacillin disks. Data were analysed using SPSS version 16 software. Out of the 177 health care workers screened, 36 (20.3%) of them were methicillin resistant Staphylococcus aureus carriers in their hand and anterior nares. More females, 25(14.1%) were colonized by methicillin resistant Staphylococcus aureus than males 11 (6.2%) (P = 0.044). Nasal carriage of MRSA of 25 (14.1%) was higher than hand carriage 11 (6.2%) (p resistant Staphylococcus aureus carriage rates of 26 (13.6%) and 4 (2.3%), respectively. The isolated MRSA were resistant to multiple antibiotics. The highest resistance was observed for ampicillin (88.9%) and tetracycline (86.1%). Two (5.6%) of the nasal isolates were vancomycin resistant. Methicillin resistant Staphylococcus aureus carriage among health care workers in this study was high. The carriage rate was higher among nurses and doctors. The MRSA isolates were multi drug resistant to other antibiotics. So, the result of this study emphasizes the need of regular surveillance of health care workers. It also calls a need for an effective infection prevention and control program.

Prevalence of methicillin-resistant Staphylococcus aureus (MRSA in community-acquired primary pyoderma

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Patil Rahul

2006-01-01

Full Text Available Background: Although prevalence of MRSA strains is reported to be increasing, there are no studies of their prevalence in community-acquired primary pyodermas in western India. Aims: This study aimed at determining the prevalence of MRSA infection in community-acquired primary pyodermas. Methods: Open, prospective survey carried out in a tertiary care hospital in Mumbai. Materials and Methods: Eighty-six patients with primary pyoderma, visiting the dermatology outpatient, were studied clinically and microbiologically. Sensitivity testing was done for vancomycin, sisomycin, gentamicin, framycetin, erythromycin, methicillin, cefazolin, cefuroxime, penicillin G and ciprofloxacin. Phage typing was done for MRSA positive strains. Results : The culture positivity rate was 83.7%. Staphylococcus aureus was isolated in all cases except two. Barring one, all strains of Staphylococcus were sensitive to methicillin. Conclusions: Methicillin resistance is uncommon in community-acquired primary pyodermas in Mumbai. Treatment with antibacterials active against MRSA is probably unwarranted for community-acquired primary pyodermas.

A Novel Chimeric Endolysin with Antibacterial Activity against Methicillin-Resistant Staphylococcus aureus.

Science.gov (United States)

Haddad Kashani, Hamed; Fahimi, Hossein; Dasteh Goli, Yasaman; Moniri, Rezvan

2017-01-01

Cysteine/histidine-dependent amidohydrolase/peptidase (CHAP) and amidase are known as catalytic domains of the bacteriophage-derived endolysin LysK and were previously reported to show lytic activity against methicillin-resistant Staphylococcus aureus (MRSA). In the current study, the in silico design and analysis of chimeric CHAP-amidase model was applied to enhance the stability and solubility of protein, which was achieved through improving the properties of primary, secondary and tertiary structures. The coding gene sequence of the chimeric CHAP-amidase was synthesized and subcloned into the pET-22(+) expression vector, and the recombinant protein was expressed in E. coli BL21 (DE3) strain. Subsequent affinity-based purification yielded ~12 mg soluble protein per liter of E. coli culture. Statistical analysis indicated that concentrations of ≥1 μg/mL of the purified protein have significant antibacterial activity against S. aureus MRSA 252 cells. The engineered chimeric CHAP-amidase exhibited 3.2 log reduction of MRSA 252 cell counts at the concentration of 10 μg/mL. A synergistic interaction between CHAP-amidase and vancomycin was detected by using checkerboard assay and calculating the fractional inhibitory concentration (FIC) index. This synergistic effect was shown by 8-fold reduction in the minimum inhibitory concentration of vancomycin. The chimeric CHAP-amidase displayed strong antibacterial activity against S. aureus, S. epidermidis , and enterococcus . However, it did not indicate any significant antibacterial activity against E. coli and Lactococcus lactis . Taken together, these findings suggest that our chimeric CHAP-amidase might represent potential to be used for the development of efficient antibacterial therapies targeting MRSA and certain Gram-positive bacteria.

Comparison of the loads and antibiotic-resistance profiles of Enterococcus species from conventional and organic chicken carcasses in South Korea.

Science.gov (United States)

Kim, Y-J; Park, J-H; Seo, K-H

2018-01-01

Antibiotic-resistant bacteria in poultry meat are a threat to public health. In this study, we compared the Enterococcus spp. loads and antibiotic-resistance profiles between carcasses of conventionally and organically raised chickens. A total of 144 chicken carcasses (72 conventional and 72 organic) was collected from local retail markets in Seoul, South Korea. Overall, 77.7% (112 of 144; 75% conventional and 80% organic) of chicken carcasses were positive for Enterococcus. The mean loads of Enterococcus spp. were greater in conventional chicken carcasses, at 2.9 ± 0.4 log CFU/mL, than those in organic chicken carcasses, at 1.78 ± 0.3 log CFU/mL (p organic chicken carcasses) was randomly selected for further analysis. The predominant species was Enterococcus faecalis in both conventional and organic chicken carcasses (57.7 and 76.9%, respectively; P > 0.05). Rates of resistance to ciprofloxacin and erythromycin, which are used in veterinary medicine in South Korea, were significantly higher in conventional chicken carcasses than in organic chicken carcasses. However, we found no difference between the rates of resistance to antibiotics such as vancomycin and tigecycline, which were not registered for use in veterinary medicine in South Korea, of Enterococcus isolates from conventional and organic chicken carcasses. In addition, although multidrug resistant isolates were obtained from both types of chicken samples, the prevalence of samples positive for Enterococcus was significantly higher in conventional chicken carcasses than in organic chicken carcasses (P organic chicken carcasses. A high level of gentamicin resistance was observed in isolates from not only conventional (5.8%) but also organic chicken (1.9%) carcasses, with no significant difference in rates between them (P > 0.05). Despite this, our results suggest that organic food certification is effective in reducing fecal contamination and the burden of antibiotic-resistant Enterococcus spp. in

Survey of Staphylococcus isolates among hospital personnel, environment and their antibiogram with special emphasis on methicillin resistance

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Shobha K

2005-01-01

Full Text Available The objective of this study was to find the prevalence of Staphylococcus spp. carriage among hospital personnel and hospital environment and their antibiogram with special emphasis on methicillin resistance. A total of 205 samples from hospital personnel and environment were collected from casualty, oncology and multidisciplinary cardiac unit ward of Kasturba Medical College Hospital, Manipal. Samples were collected using sterile cotton wool swabs and inoculated into brain heart infusion broth. Subcultures were done onto blood agar and MacConkey′s agar. Isolates were identified by standard methods up to species level. Antimicrobial susceptibility test was performed according to standardized disc diffusion Kirby-Bauer method. Each of the isolates was screened for methicillin resistance using oxacillin disc on Mueller Hinton agar plate followed by MIC for methicillin and cefoxitin susceptibility test by disc diffusion method. Sixty five out of 205 strains (31.7% were Staphylococcus spp. and all of them were coagulase negative. Most of the strains belonged to S.epidermidis 49.23%(32/65 followed by S. saprophyticus 26.15%(17/65. Maximum isolates of S.epidermidis were from anterior nares 28.12%(9/32 strains of S.epidermidis . Highest number of methicillin resistant coagulase negative strains (3/9, 33.33% were isolated from stethoscope of multidisciplinary cardiac unit ward followed by carriers in the anterior nares (2/9, 22.22%. Methicillin resistant coagulase negative staphylococci are prevalent in anterior nares of hospital personnel and in the hospital environment thereby providing a definite source for hospital acquired infection. All isolates were sensitive to vancomycin, ciprofloxacin and amikacin.

Retrospective Analysis of Clinical and Cost Outcomes Associated with Methicillin-Resistant Staphylococcus aureus Complicated Skin and Skin Structure Infections Treated with Daptomycin, Vancomycin, or Linezolid

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Bradley M. Wright

2011-01-01

Full Text Available Objective. The objective of this analysis was to compare clinical and cost outcomes associated with patients who had suspected or documented methicillin-resistant Staphylococcus aureus (MRSA infections treated with daptomycin, vancomycin, or linezolid in complicated skin and skin structure infections (cSSSIs. Design. This was a retrospective analysis conducted from February to June of 2007. Appropriate data was collected, collated, and subsequently evaluated with the purpose of quantifying length of stay, antibiotic therapy duration, clinical cure rates, adverse drug events, and cost of hospitalization. Results. All 82 patients included in the analysis experienced clinical cure. The duration of antibiotic therapy was similar among the three groups yet the length of hospitalization was slightly shorter in the daptomycin group. Conclusions. The incidence of resistant staphylococcal infections is increasing; therefore, judicious use of MRSA active agents is paramount. Future studies are necessary to determine if MRSA treatment options can be stratified based on the severity of the infectious process.

Detection Antibiotic Resistance of Enviromental Bacterial Strains

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Huda Zuheir Majeed

2018-05-01

Full Text Available      Antibiotics are randomly prescribed  for veterinary and human medication. Antibiotics by little number are used by human , animals are digested uncompletely  in their digestive system and ended up in communal sewage and hospitals, eventually discharge in environmental water sources directly with no processing.     Water itself consider as major factor of dispersal of bacteria between different environmental components. Besides, bacteria had  transferable genetic mobile elements to different sites of soil, water and humans.       Environmental swabs were collected locally including 50 swabs of hospital environment , 15 samples of poultry feces and chicken guts , 20 sample of heavy water and 15 sample of fish tank to identify16 isolate of Staphylococcus (4 isolate of Staphylococus aureus and 12 isolate of coagulase –ve Staphylococcus , 19 isolate of Enterococcus spp. , 7 isolates of Pseudomonas and 5 environment isolates for each Shigella spp.  and Salmonella spp. .           Teicoplanin and Vancomycin sensitivity test of isolates was done , showing that 2out of 16 isolates of Staphylococcus (12.5% were Vancomycin-resistant , and 3out of 19 isolates of Enterococcus (15.7 % were Vancomycin-resistant, while the rest of isolates were Vancomycin- sensitive. From other side , all isolates was Teicoplanin- sensitive except only 1 Enterococcus spp. Isolate which was intermediate . The range of the Vancomycin MIC were (6-64 µg/ml . Vancomycin resistant isolates , showed that some isolates have one plasmid band after Extraction of their DNA.

Methicillin-resistant Staphylococci in companion animals

DEFF Research Database (Denmark)

Baptiste, Keith Edward; Williams, Kerry; Williams, Nicola J.

2005-01-01

We determined the molecular characteristics of methicillin-resistant staphylococci from animals and staff at a small animal and equine hospital. Methicillin-restistant Staphylococcus aureus identical to human EMRSA-15 was found in dogs and hospitalstaff. In contrast, 5 distinct MRSA strains were...

Public transport as a reservoir of methicillin-resistant staphylococci.

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Stepanović, S; Cirković, I; Djukić, S; Vuković, D; Svabić-Vlahović, M

2008-10-01

The aim of this study was to explore the occurrence of methicillin-resistant staphylococci in a large urban public transport system. Samples were taken from hand rails, which passengers hold onto when they are standing. In total, 1400 swabs taken from 55 vehicles (trolleybuses, trams and buses) were examined. As many as 30.1% samples were positive for the presence of methicillin-resistant coagulase-negative staphylococci (MRCoNS), but none for methicillin-resistant Staphylococcus aureus (MRSA). MRCoNS were isolated from all 55 vehicles. Nearly 50% of MRCoNS isolates displayed resistance not only to beta-lactams, but at least to two or more other classes of antimicrobials as well. This study demonstrated widespread occurrence of MRCoNS on hand rails in public transport vehicles. MRSA was not detected. The recovery of methicillin-resistant staphylococci from public transport system implies a potential risk for transmission of these bacteria in an out-hospital environment.

Methicillin-resistant Staphylococcus aureus in Zimbabwe ...

African Journals Online (AJOL)

Resistance was high for most widely used drugs in Zimbabwe with high sensitivity to vancomycin, linezolid and teicoplanin. Conclusion: Although there are no recent reports in the literature of the presence of MRSA in Zimbabwe, this study documented a 7.0% prevalence. Resistance to common antibiotics is high and ...

Crystallization and preliminary X-ray analysis of a d-Ala:d-Ser ligase associated with VanG-type vancomycin resistance

International Nuclear Information System (INIS)

Weber, Patrick; Meziane-Cherif, Djalal; Haouz, Ahmed; Saul, Frederick A.; Courvalin, Patrice

2009-01-01

The VanG d-alanine:d-serine ligase was crystallized in complex with ADP and diffraction data were collected at 2.35 Å resolution. Acquired VanG-type resistance to vancomycin in Enterococcus faecalis BM4518 arises from inducible synthesis of peptidoglycan precursors ending in d-alanyl-d-serine, to which vancomycin exhibits low binding affinity. VanG, a d-alanine:d-serine ligase, catalyzes the ATP-dependent synthesis of the d-Ala-d-Ser dipeptide, which is incorporated into the peptidoglycan synthesis of VanG-type vancomycin-resistant strains. Here, the purification, crystallization and preliminary crystallographic analysis of VanG in complex with ADP are reported. The crystal belonged to space group P3 1 21, with unit-cell parameters a = b = 116.1, c = 177.2 Å, and contained two molecules in the asymmetric unit. A complete data set has been collected to 2.35 Å resolution from a single crystal under cryogenic conditions using synchrotron radiation

Phenotypic and genomic comparisons of highly vancomycin-resistant Staphylococcus aureus strains developed from multiple clinical MRSA strains by in vitro mutagenesis.

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Ishii, Kenichi; Tabuchi, Fumiaki; Matsuo, Miki; Tatsuno, Keita; Sato, Tomoaki; Okazaki, Mitsuhiro; Hamamoto, Hiroshi; Matsumoto, Yasuhiko; Kaito, Chikara; Aoyagi, Tetsuji; Hiramatsu, Keiichi; Kaku, Mitsuo; Moriya, Kyoji; Sekimizu, Kazuhisa

2015-11-25

The development of vancomycin (VCM) resistance in Staphylococcus aureus threatens global health. Studies of the VCM-resistance mechanism and alternative therapeutic strategies are urgently needed. We mutagenized S. aureus laboratory strains and methicillin-resistant S. aureus (MRSA) with ethyl methanesulfonate, and isolated mutants that exhibited high resistance to VCM (minimum inhibitory concentration = 32 μg/ml). These VCM-resistant strains were sensitive to linezolid and rifampicin, and partly to arbekacin and daptomycin. Beta-lactams had synergistic effects with VCM against these mutants. VCM-resistant strains exhibited a 2-fold increase in the cell wall thickness. Several genes were commonly mutated among the highly VCM-resistant mutants. These findings suggest that MRSA has a potential to develop high VCM resistance with cell wall thickening by the accumulation of mutations.

Quality control of direct molecular diagnostics for methicillin-resistant Staphylococcus aureus

NARCIS (Netherlands)

van Belkum, Alex; Niesters, Hubert G M; MacKay, William G; van Leeuwen, Willem B

Ten samples containing various amounts of methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible S. aureus, methicillin-resistant Staphylococcus epidermidis (MRSE), and combinations thereof were distributed to 51 laboratories for molecular diagnostics testing. Samples containing

Methicillin-resistant Staphylococcus aureus isolates from Iranian ...

African Journals Online (AJOL)

Methicillin-resistant Staphylococcus aureus isolates from Iranian restaurant food samples: Panton-Valentine Leukocidin, SCCmec phenotypes and antimicrobial resistance. ... TetK (80.72 %), linA (67.46 %), aadA1 (62.65 %), and msrA (55.42 %) were the most frequently identified resistance genes. SCCmec V (57.83%) ...

Oxacillin sensitization of methicillin-resistant Staphylococcus aureus and methicillin-resistant Staphylococcus pseudintermedius by antisense peptide nucleic acids in vitro.

Science.gov (United States)

Goh, Shan; Loeffler, Anette; Lloyd, David H; Nair, Sean P; Good, Liam

2015-11-11

Antibiotic resistance genes can be targeted by antisense agents, which can reduce their expression and thus restore cellular susceptibility to existing antibiotics. Antisense inhibitors can be gene and pathogen specific, or designed to inhibit a group of bacteria having conserved sequences within resistance genes. Here, we aimed to develop antisense peptide nucleic acids (PNAs) that could be used to effectively restore susceptibility to β-lactams in methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus pseudintermedius (MRSP). Antisense PNAs specific for conserved regions of the mobilisable gene mecA, and the growth essential gene, ftsZ, were designed. Clinical MRSA and MRSP strains of high oxacillin resistance were treated with PNAs and assayed for reduction in colony forming units on oxacillin plates, reduction in target gene mRNA levels, and cell size. Anti-mecA PNA at 7.5 and 2.5 μM reduced mecA mRNA in MRSA and MRSP (p resistance in staphylococci. Further studies are warranted as clinical treatment alternatives are needed.

Methicillin resistance of airborne coagulase-negative staphylococci in homes of persons having contact with a hospital environment.

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Lis, Danuta O; Pacha, Jerzy Z; Idzik, Danuta

2009-04-01

The persons having contact with a hospital environment (hospital personnel workers and discharged patients) are highly exposed to colonization with multidrug-resistant bacteria. The aim of this study was to evaluate the airborne Staphylococcus genus features in homes in which inhabitants have had contact with the hospital environment. Airborne bacteria were collected using a 6-stage Anderson impactor. The Staphylococcus species composition and resistance to methicillin, and other antimicrobial agents among 3 coagulase-negative staphylococci (CNS) species (S cohnii spp cohnii, S epidermidis, S hominis), were determined. Antibiotic resistance of isolates was tested using the agar screen method with methicillin, the polymerase chain reaction technique to detect the mecA gene, and the disk diffusion method. A higher prevalence of methicillin-resistant (MR) strains among the species isolated (40% of S epidermidis, 40% of S hominis, and 60% of S cohnii spp cohnii) was found in homes of persons who had contact with a hospital environment compared with the reference homes (only 12% of S hominis). The mecA gene was revealed in all MR S epidermidis strains and in some MR S hominis (50%) and S cohnii spp cohnii (33%) strains. All isolated MR CNS strains were susceptible to vancomycin, rifampicin, and linezolid. High numbers of airborne multidrug-resistant MR CNS in the homes of persons having contact with a hospital environment indicates that such inhabitants pose a risk of intrafamilial spreading of MR strains via air.

Molecular and phenotypic characteristics of methicillin-resistant Staphylococcus aureus isolated from hospitalized patients.

Science.gov (United States)

de Oliveira, Caio Ferreira; Morey, Alexandre Tadachi; Santos, Jussevania Pereira; Gomes, Ludmila Vilela Pereira; Cardoso, Juscélio Donizete; Pinge-Filho, Phileno; Perugini, Márcia Regina Eches; Yamauchi, Lucy Megumi; Yamada-Ogatta, Sueli Fumie

2015-07-30

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of infections acquired in both community and hospital settings. In this study, MRSA isolated from different sources of hospitalized patients was characterized by molecular and phenotypic methods. A total of 123 S. aureus isolates were characterized according to their genetic relatedness by repetitive element sequence based-PCR (REP-PCR), in vitro antimicrobial susceptibility profile, SCCmec typing and presence of seven virulence factor-encoding genes. REP-PCR fingerprinting showed low relatedness between the isolates, and the predominance of one specific lineage or clonal group was not observed. All isolates were susceptible to teicoplanin and linezolide. All isolates were resistant to cefoxitin and penicillin, and the majority were also resistant to one or more other antimicrobials. Fifty isolates (41.7%) were intermediately resistant to vancomycin. Most isolates harbored SCCmec type II (53.7%), followed by type I (22.8%), type IV (8.1%) and type III (1.6%). All isolates harbored at least two virulence factor-encoding genes, and the prevalence was as follows: coa, 100%; icaA, 100%; hla, 13.0%; hlb, 91.1%, hld, 91.1%; lukS-PV and lukF-PV, 2.4%; and tst, 34.1%. A positive association with the presence of hla and SCCmec type II, and tst and SCCmec type I was observed. This study showed the high virulence potential of multidrug-resistant MRSA circulating in a teaching hospital. A high prevalence of MRSA showing intermediate vancomycin resistance was also observed, indicating the urgent need to improve strategies for controlling the use of antimicrobials for appropriate management of S. aureus infections.

Use of antimicrobial growth promoters in food animals and Enterococcus faecium resistance to therapeutic antimicrobial drugs in Europe

DEFF Research Database (Denmark)

Wegener, Henrik Caspar; Aarestrup, Frank Møller; Jensen, Lars Bogø

1999-01-01

on the Tn1546 transposon. Furthermore, glycopeptide-resistant strains, as well as resistance determinants, can be transmitted from animals to humans. Two antimicrobial classes expected to provide the future therapeutic options for treatment of infections with vancomycin-resistant enterococci have analogues......Supplementing animal feed with antimicrobial agents to enhance growth has been common practice for more than 30 years and is estimated to constitute more than half the total antimicrobial use worldwide. The potential public health consequences of this use have been debated; however, until recently......, clear evidence of a health risk was not available. Accumulating evidence now indicates that the use of the glycopeptide avoparcin as a growth promoter has created in food animals a major reservoir of Enterococcus faecium, which contains the high level glycopeptide resistance determinant vanA, located...

Prevalence of methicillin-resistant Staphylococcus aureus and ...

African Journals Online (AJOL)

Wound colonization by microorganisms is most frequently polymicrobial and incidences of high level resistance among bacterial isolates from wounds have been reported. Methicillin-resistant Staphylococcus aureus (MRSA) and extendedspectrum beta-lactamase (ESBL) producing Gram-negative bacteria both constitute ...

Methicillin-resistant Staphylococcus aureus in North-east Croatia

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Tajana Pastuović

2015-05-01

Full Text Available Objective. The aim of this 5-year study was to determine the frequency and antibiotic susceptibility of methicillin-resistant Staphylococcus aureus (MRSA-related infections at Osijek Clinical Hospital. Materials and methods. A total of 1987 staphylococci-infected clinical isolates were collected and analysed at the Microbiology Department of the Public Health Institute of Osijek-Baranja County. Results. Between 2008 and 2012, the average rate of MRSA-related infections in staphylococci-infected patients was 27.4%. The proportion of MRSArelated infections on all Staphylococcus aureus (S. aureus isolates from clinical specimens showed a decreasing trend, from 32.6% in 2008 to 25.5% in 2012. MRSA-related infections were mostly detected in wound swabs (50.6% and aspirates (28.8% of patients hospitalized in the surgical (49.8% and intensive care units (27.9%. MRSA-related infection showed an increase compared to S. aureus-infections in samples of wounds and aspirates in 2011 and 2012 (57.9%/34.9% and 35.2%/16.3%, respectively. The majority of strains of MRSA-related infections were resistant to several antibiotics, including erythromycin and clindamycin, where susceptibility were less than 10%. All MRSA isolates were susceptible to vancomycin, teicoplanin and linezolid. Therefore, antibiotic therapies for MRSA infections include vancomycin, teicoplanin and linezolid, but microbiological diagnostics need to be performed in order to know when the use of glycopeptides and oxazolidinones is indicated. Conclusion. Our results suggest that appropriate prevention measures, combined with the more rational use of antibiotics are crucial to reduce the spread of MRSA-related infection in healthcare settings. Further monitoring is necessary of the incidence and antibiotic susceptibility of MRSA-related infections in our community.

Methicillin-resistant Staphylococcus aureus emerged long before the introduction of methicillin into clinical practice.

Science.gov (United States)

Harkins, Catriona P; Pichon, Bruno; Doumith, Michel; Parkhill, Julian; Westh, Henrik; Tomasz, Alexander; de Lencastre, Herminia; Bentley, Stephen D; Kearns, Angela M; Holden, Matthew T G

2017-07-20

The spread of drug-resistant bacterial pathogens poses a major threat to global health. It is widely recognised that the widespread use of antibiotics has generated selective pressures that have driven the emergence of resistant strains. Methicillin-resistant Staphylococcus aureus (MRSA) was first observed in 1960, less than one year after the introduction of this second generation beta-lactam antibiotic into clinical practice. Epidemiological evidence has always suggested that resistance arose around this period, when the mecA gene encoding methicillin resistance carried on an SCCmec element, was horizontally transferred to an intrinsically sensitive strain of S. aureus. Whole genome sequencing a collection of the first MRSA isolates allows us to reconstruct the evolutionary history of the archetypal MRSA. We apply Bayesian phylogenetic reconstruction to infer the time point at which this early MRSA lineage arose and when SCCmec was acquired. MRSA emerged in the mid-1940s, following the acquisition of an ancestral type I SCCmec element, some 14 years before the first therapeutic use of methicillin. Methicillin use was not the original driving factor in the evolution of MRSA as previously thought. Rather it was the widespread use of first generation beta-lactams such as penicillin in the years prior to the introduction of methicillin, which selected for S. aureus strains carrying the mecA determinant. Crucially this highlights how new drugs, introduced to circumvent known resistance mechanisms, can be rendered ineffective by unrecognised adaptations in the bacterial population due to the historic selective landscape created by the widespread use of other antibiotics.

Phenotypic and molecular characteristics of methicillin-resistant Staphylococcus aureus isolates from Ekiti State, Nigeria

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Olowe OA

2013-08-01

Full Text Available Olugbenga Adekunle Olowe,1 Olayinka Oluwatoyin Kukoyi,2 Samuel Sunday Taiwo,1 Olusola Ojurongbe,1 Oluyinka Oladele Opaleye,1 Oloyede Samuel Bolaji,1 Abiodun Adebimpe Adegoke,1 Olufunmilola Bamidele Makanjuola,1 David Olusoga Ogbolu,3 Oyebode Terry Alli31Department of Medical Microbiology and Parasitology, College of Health Sciences, Ladoke Akintola University of Technology, Ogbomoso, Nigeria; 2Department of Microbiology, College of Sciences, Afe Babalola University, Ado-Ekiti, Nigeria; 3Department of Biomedical Sciences, College of Health Sciences, Lautech, Osogbo, NigeriaIntroduction: The characteristics and antimicrobial resistance profiles of Staphylococcus aureus differs according to geographical regions and in relation to antibiotic usage. The aim of this study was to determine the biochemical characteristics of the prevalent S. aureus from Ekiti State, Nigeria, and to evaluate three commonly used disk diffusion methods (cefoxitin, oxacillin, and methicillin for the detection of methicillin resistance in comparison with mecA gene detection by polymerase chain reaction.Materials and methods: A total of 208 isolates of S. aureus recovered from clinical specimens were included in this study. Standard microbiological procedures were employed in isolating the strains. Susceptibility of each isolate to methicillin (5 µg, oxacillin (1 µg, and cefoxitin (30 µg was carried out using the modified Kirby–Bauer/Clinical and Laboratory Standard Institute disk diffusion technique. They were also tested against panels of antibiotics including vancomycin. The conventional polymerase chain reaction method was used to detect the presence of the mecA gene.Results: Phenotypic resistance to methicillin, oxacillin, and cefoxitin were 32.7%, 40.3%, and 46.5%, respectively. The mecA gene was detected in 40 isolates, giving a methicillin-resistant S. aureus (MRSA prevalence of 19.2%. The S. aureus isolates were resistant to penicillin (82.7% and tetracycline

Adaptation of Enterococcus faecalis to daptomycin reveals an ordered progression to resistance.

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Miller, Corwin; Kong, Jiayi; Tran, Truc T; Arias, Cesar A; Saxer, Gerda; Shamoo, Yousif

2013-11-01

With increasing numbers of hospital-acquired antibiotic resistant infections each year and staggering health care costs, there is a clear need for new antimicrobial agents, as well as novel strategies to extend their clinical efficacy. While genomic studies have provided a wealth of information about the alleles associated with adaptation to antibiotics, they do not provide essential information about the relative importance of genomic changes, their order of appearance, or potential epistatic relationships between adaptive changes. Here we used quantitative experimental evolution of a single polymorphic population in continuous culture with whole-genome sequencing and allelic frequency measurements to study daptomycin (DAP) resistance in the vancomycin-resistant clinical pathogen Enterococcus faecalis S613. Importantly, we sustained both planktonic and nonplanktonic (i.e., biofilm) populations in coculture as the concentration of antibiotic was raised, facilitating the development of more ecological complexity than is typically observed in laboratory evolution. Quantitative experimental evolution revealed a clear order and hierarchy of genetic changes leading to resistance, the signaling and metabolic pathways responsible, and the relative importance of these mutations to the evolution of DAP resistance. Despite the relative simplicity of this ex vivo approach compared to the ecological complexity of the human body, we showed that experimental evolution allows for rapid identification of clinically relevant adaptive molecular pathways and new targets for drug design in pathogens.

Detection of meca gene from methicillin resistant staphylococcus aureus isolates of north sumatera

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Septiani Nasution, Gabriella; Suryanto, Dwi; Lia Kusumawati, R.

2018-03-01

Methicillin Resistant Staphylococcus aureus (MRSA) is a major pathogen associated with hospital-acquired infections (nosocomial infections). MRSA is a type of S. aureus resistant to the sub-group of beta-lactam antibiotics such as penicillin, cephalosporin, monobactam, and carbapenem. MRSA is resistant because of genetic changes caused by exposure to irrational antibiotic therapy. This study aimed to detect mecA gene in North Sumatra isolates of MRSA and to determine the pattern of antibiotic resistance in S.aureus isolates classified as MRSA by Vitek 2 Compact in the Central Public Hospital Haji Adam Malik, Medan. Samples were 40 isolates of S. aureus classified as MRSA obtained from clinical microbiology specimens. DNA isolation of the isolates was conducted by a method of freeze-thaw cycling. Amplification of mecA gene was done by PCR technique using specific primer for the gene. PCR products were visualized using mini-gel electrophoresis. The results showed that all MRSA isolates showed to have 533 bp band of mecA. Antibiotics test of Vitek 2 Compact showed that despite all isolates were resistant to beta-lactam antibiotics groups; the isolates showed multidrug resistant to other common antibiotics, such as aminoglycosides, macrolides, and fluoroquinolones. However, they were still sensitive to vancomycin (82.5% isolates), linezolid (97.5% isolates), and tigecycline (100% isolates).

In vitro transfer of methicillin resistance determinants mecA from methicillin resistant Staphylococcus aureus (MRSA) to methicillin susceptible Staphylococcus aureus (MSSA).

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Bitrus, Asinamai Athliamai; Zunita, Zakaria; Bejo, Siti Khairani; Othman, Sarah; Nadzir, Nur Adilah Ahmad

2017-04-04

Staphylococcus aureus more than any other human pathogen is a better model for the study of the adaptive evolution of bacterial resistance to antibiotics, as it has demonstrated a remarkable ability in its response to new antibiotics. This study was designed to investigate the in vitro transfer of mecA gene from methicillin resistant S. aureus to methicillin susceptible S. aureus. The recipient transconjugants were resistant to erythromycin, cefpodoxime and were mecA positive. PCR amplification of mecA after mix culture plating on Luria Bertani agar containing 100 μg/mL showed that 75% of the donor and 58.3% of the recipient transconjugants were mecA positive. Additionally, 61.5% of both the donor cells and recipient transconjugants were mecA positive, while 46.2% and 41.75% of both donor and recipient transconjugants were mecA positive on LB agar containing 50 μg/mL and 30 μg/mL respectively. In this study, the direction of transfer of phenotypic resistance as well as mecA was observed to have occurred from the donor to the recipient strains. This study affirmed the importance of horizontal transfer events in the dissemination of antibiotics resistance among different strains of MRSA.

Mechanisms of antibiotic resistance in Staphylococcus aureus.

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Pantosti, Annalisa; Sanchini, Andrea; Monaco, Monica

2007-06-01

Staphylococcus aureus can exemplify better than any other human pathogen the adaptive evolution of bacteria in the antibiotic era, as it has demonstrated a unique ability to quickly respond to each new antibiotic with the development of a resistance mechanism, starting with penicillin and methicillin, until the most recent, linezolid and daptomycin. Resistance mechanisms include enzymatic inactivation of the antibiotic (penicillinase and aminoglycoside-modification enzymes), alteration of the target with decreased affinity for the antibiotic (notable examples being penicillin-binding protein 2a of methicillin-resistant S. aureus and D-Ala-D-Lac of peptidoglycan precursors of vancomycin-resistant strains), trapping of the antibiotic (for vancomycin and possibly daptomycin) and efflux pumps (fluoroquinolones and tetracycline). Complex genetic arrays (staphylococcal chromosomal cassette mec elements or the vanA operon) have been acquired by S. aureus through horizontal gene transfer, while resistance to other antibiotics, including some of the most recent ones (e.g., fluoroquinolones, linezolid and daptomycin) have developed through spontaneous mutations and positive selection. Detection of the resistance mechanisms and their genetic basis is an important support to antibiotic susceptibility surveillance in S. aureus.

EFFECT OF LINEZOLID ALONE AND IN COMBINATION WITH OTHER ANTIBIOTICS, ON METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS.

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Yehia, Hoda; El Said, Manal; Azmy, Magda; Badawy, Moushira; Mansy, Soheir; Gohar, Hamida; Madany, Nadia

2016-04-01

The prevalence of methicillin-resistant Staphyloccoccus aureus (MRSA) strains has presented a new challenge in antimicrobial medication. Linezolid is a new drug with potent activity on Gram-positive pathogens such as MRSA. The aim of the study was to investigate the in vitro activity of linezolid alone and in combination with imipenem, vancomycin or rifampicin to determine the most active therapy against MRSA strains. Twenty clinical MRSA strains were isolated from patients admitted to inpatient departments and outpatient clinics of Theodor Bilharz Research Institute. Standard strain MRSA ATCC 43300 was included as a control. The MICs of MRSA strains to linezolid, vancomycin, imipenem and rifampicin were evaluated using E test. Time-kill curve were used to assess the in vitro activity of linezolid (at 8x MIC) alone and in combination with imipenem (at 32x MIC), vancomycin or rifampicin (at 8x MIC). Scanning and transmission electron microscopy were performed to compare bacterial morphological alterations owing to the different combi- nations. Time-kill studies showed synergistic effect when linezolid combined with imipenem was tested against all the MRSA strains. Linezolid plus vancomycin or rifampicin combinations did not display any synergism or antagonism. Scanning and transmission electron microscopy observations confirmed the interactions observed in time kill experiments. Linezolid in combination with subinhibitory concentrations of imipenem can be bactericidal against MRSA strains and appears to be a promising combination for the treatment of MRSA infections. No synergistic activity was seen when the linezolid and vancomycin or rifampicin were combined. Linezolid could prevent the emergence of mutants resistant to rifampicin

Occurrence of methicillin-resistant Staphylococci in surgically treated dogs and the environment in a Swedish animal hospital.

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Bergström, A; Gustafsson, C; Leander, M; Fredriksson, M; Grönlund, U; Trowald-Wigh, G

2012-07-01

To investigate whether hospitalised dogs treated surgically may become culture positive for methicillin-resistant Staphylococcus pseudintermedius or methicillin-resistant Staphylococcus aureus. Surgically treated dogs (n=45) were sampled for methicillin-resistant Staphylococcus pseudintermedius or methicillin-resistant Staphylococcus aureus on admission, before and after surgery and at the time of removal of surgical stitches. The hospital environment (n=57), including healthy dogs in the veterinary hospital environment (n=34), were sampled for methicillin-resistant Staphylococcus pseudintermedius or methicillin-resistant Staphylococcus aureus. Genetic variations among methicillin-resistant Staphylococcus pseudintermedius or methicillin-resistant Staphylococcus aureus isolates were identified through detection of restriction fragment polymorphisms. No dogs developed a wound infection due to methicillin-resistant Staphylococcus pseudintermedius or methicillin-resistant Staphylococcus aureus. However, there was a significant increase in the number of dogs carrying methicillin-resistant Staphylococcus pseudintermedius after hospitalisation compared to admission (Ppresent in the environment. Methicillin-resistant Staphylococcus pseudintermedius isolates were recovered from environmental surfaces and hospitalised animals, but not from healthy dogs. Methicillin-resistant Staphylococcus pseudintermedius isolates representing nine different restriction endonuclease digestion patterns were found, with two of these occurring in both the environment and on dogs. Dogs may contract methicillin-resistant Staphylococcus pseudintermedius in association with surgery and hospitalisation. Resistant bacteria may be transmitted between dogs, staff and the environment. Dogs colonised with methicillin-resistant Staphylococcus pseudintermedius may be a source for hospital- and community-acquired infections. © 2012 British Small Animal Veterinary Association.

Comparative effectiveness of nafcillin or cefazolin versus vancomycin in methicillin-susceptible Staphylococcus aureus bacteremia

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McGregor Jessina C

2011-10-01

Full Text Available Abstract Background The high prevalence of methicillin-resistant S. aureus (MRSA has led clinicians to select antibiotics that have coverage against MRSA, usually vancomycin, for empiric therapy for suspected staphylococcal infections. Clinicians often continue vancomycin started empirically even when methicillin-susceptible S. aureus (MSSA strains are identified by culture. However, vancomycin has been associated with poor outcomes such as nephrotoxicity, persistent bacteremia and treatment failure. The objective of this study was to compare the effectiveness of vancomycin versus the beta-lactam antibiotics nafcillin and cefazolin among patients with MSSA bacteremia. The outcome of interest for this study was 30-day in-hospital mortality. Methods This retrospective cohort study included all adult in-patients admitted to a tertiary-care facility between January 1, 2003 and June 30, 2007 who had a positive blood culture for MSSA and received nafcillin, cefazolin or vancomycin. Cox proportional hazard models were used to assess independent mortality hazards comparing nafcillin or cefazolin versus vancomycin. Similar methods were used to estimate the survival benefits of switching from vancomycin to nafcillin or cefazolin versus leaving patients on vancomycin. Each model included statistical adjustment using propensity scores which contained variables associated with an increased propensity to receive vancomycin. Results 267 patients were included; 14% (38/267 received nafcillin or cefazolin, 51% (135/267 received both vancomycin and either nafcillin or cefazolin, and 35% (94/267 received vancomycin. Thirty (11% died within 30 days. Those receiving nafcillin or cefazolin had 79% lower mortality hazards compared with those who received vancomycin alone (adjusted hazard ratio (HR: 0.21; 95% confidence interval (CI: 0.09, 0.47. Among the 122 patients who initially received vancomycin empirically, those who were switched to nafcillin or cefazolin (66

Molecular Typing and Antimicrobial Susceptibility of Methicillin-Resistant Staphylococcus aureus Isolated from Bovine Milk in Tanzania.

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Mohammed, Jibril; Ziwa, Michael Henry; Hounmanou, Yaovi Mahuton Gildas; Kisanga, Adela; Tuntufye, Huruma Nelwike

2018-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) in raw milk can be transmitted from animals to humans, and in Tanzania raw milk is sold in local markets and consumed as purchased. This study was performed to determine the molecular characteristics and antimicrobial susceptibility pattern of MRSA strains isolated from raw bovine milk sold at local markets in Tanzania. A total of 117 raw milk samples were cultured on Baird-Parker medium to isolate S. aureus and PCR was used for amplification of gltB gene for S. aureus identification and the presence of mecA gene for methicillin-resistant strains. Coagulase-negative (CN) S. aureus were reconfirmed using tube coagulase, DNase, and API Staph tests. MRSA isolates were spa typed whereas antimicrobial susceptibility testing was performed by the disc diffusion method. Forty-six coagulase positives (CP) and two CN S. aureus were identified. Most strains were resistant to penicillin (72%), and 3 isolates: 2 CN S. aureus and 1 coagulase-negative Staphylococci (CNS), were phenotypically resistant to vancomycin, oxacillin, and cefoxitin and were confirmed to carry mecA. Resistance to clindamycin, trimethoprim-sulfamethoxazole, and tetracycline was 23.9%, 30.4%, and 41.3%, respectively. Twelve isolates exhibited multidrug resistance; however, only one mecA positive strain among the three was typeable and belonged to spa type t2603. This study reports for the first time the presence of CN variant of MRSA, which was assigned the spa type t2603, and the presence of multidrug resistant S. aureus isolates from bovine milk in Morogoro, Tanzania.

Vancomycin-resistant enterococci: validation of susceptibility testing and in vitro activity of novel antibiotics

DEFF Research Database (Denmark)

Rathe, Mathias; Lise, Kristensen,; Ellermann-Eriksen, Svend

Vancomycin-resistant enterococci: validation of susceptibility testing and in vitro activity of novel antibiotics......Vancomycin-resistant enterococci: validation of susceptibility testing and in vitro activity of novel antibiotics...

ANTIBIOTIC RESISTANCE IN LACTIC ACID BACTERIA ISOLATED FROM FERMENTED DAIRY PRODUCTS AND BOZA

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Gamze Başbülbül

2015-06-01

Full Text Available In this study, the resistance of 83 strains of lactic acid bacteria isolated from Turkish cheese, yogurt, kefir and boza samples to 6 antibiotics (gentamicin, tetracycline, chloramphenicol, erythromycin, vancomycin and ciprofloxacin was evaluated. The 83 isolates were identified by 16S rRNA gene sequencing and according to BLAST comparisons with sequences in the data banks, those strains showing the highest similarities with the isolates were Enterococcus faecium (10, Lactococcus lactis subsp. Lactis (10, Lactobacillus fermentum (6, Lactobacillus plantarum (6, Lactobacillus coryniformis (7, Lactobacillus casei (13, Leuconostoc mesenteroides (14, Pediococcus pentosaceus (10, Weisella confusa (7. Antimicrobial resistance of strains to 6 antibiotics was determined using the agar dilution method. The antibiotic resistance among all the isolates was detected against chloramphenicol (31,3 % of the isolates, tetracycline (30,1 %, erythromycin (2,4 %, ciprofloxacin (2,41%, vancomycin (73,5 %, intrinsic resistance. Overall 19,3 % of the isolates showed resistance against multiple antibiotics. Antibiotic resistance genes were studied by PCR and the following genes were detected; tet(M gene in Lactobacillus fermentum (1, Lactobacillus plantarum (1, Pediococcus pentosaceus (5, Enterococcus faecium (2, Weisella confusa (4 and the vancomycin resistance gene van(A in one Weisella confusa strain.

Successful treatment of methicillin-resistant Staphylococcus aureus osteomyelitis with combination therapy using linezolid and rifampicin under therapeutic drug monitoring.

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Ashizawa, Nobuyuki; Tsuji, Yasuhiro; Kawago, Koyomi; Higashi, Yoshitsugu; Tashiro, Masato; Nogami, Makiko; Gejo, Ryuichi; Narukawa, Munetoshi; Kimura, Tomoatsu; Yamamoto, Yoshihiro

2016-05-01

Linezolid is an effective antibiotic against most gram-positive bacteria including drug-resistant strains such as methicillin-resistant Staphylococcus aureus. Although linezolid therapy is known to result in thrombocytopenia, dosage adjustment or therapeutic drug monitoring of linezolid is not generally necessary. In this report, however, we describe the case of a 79-year-old woman with recurrent methicillin-resistant S. aureus osteomyelitis that was successfully treated via surgery and combination therapy using linezolid and rifampicin under therapeutic drug monitoring for maintaining an appropriate serum linezolid concentration. The patient underwent surgery for the removal of the artificial left knee joint and placement of vancomycin-impregnated bone cement beads against methicillin-resistant S. aureus after total left knee implant arthroplasty for osteoarthritis. We also initiated linezolid administration at a conventional dose of 600 mg/h at 12-h intervals, but reduced it to 300 mg/h at 12-h intervals on day 9 because of a decrease in platelet count and an increase in serum linezolid trough concentration. However, when the infection exacerbated, we again increased the linezolid dose to 600 mg/h at 12-h intervals and performed combination therapy with rifampicin, considering their synergistic effects and the control of serum linezolid trough concentration via drug interaction. Methicillin-resistant S. aureus infection improved without reducing the dose of or discontinuing linezolid. The findings in the present case suggest that therapeutic drug monitoring could be useful for ensuring the therapeutic efficacy and safety of combination therapy even in patients with osteomyelitis who require long-term antibiotic administration. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

The molecular changing mechanism of Ampicillin-Sulbactam resistant Staphylococcus aureus towards Methicillin resistant Staphylococcus aureus

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Mieke Hemiawati Satari

2005-12-01

Full Text Available The aim of this study was to determine the molecular changing of S.aureus, which is resistant to Ampicillin-Sulbactam and then become resistant to Methicillin as a result of improper dosage. The study was conducted by isolating Ampicillin-Sulbactam resistant and Methicillin Resistant S.aureus (MRSA, afterwards an amplification process was performed by PCR (Polymerase Chain Reaction. to isolate the betalactamase enzyme regulator and PBP 2a genes. The result of this research showed that there were a deletion of few amino acids from the regulator gene, and a suspicion that the DNA sequence had been substituted from PBP 2 gene into PBP 2a (gen mec. This process had formed MRSA.

Evaluation of the synergistic potential of vancomycin combined with other antimicrobial agents against methicillin-resistant Staphylococcus aureus and coagulase-negative Staphylococcus spp strains

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Lívia Viganor da Silva

2011-02-01

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA and coagulase-negative Staphylococcus spp (CNS are the most common pathogens that cause serious long term infections in patients. Despite the existence of new antimicrobial agents, such as linezolid, vancomycin (VAN remains the standard therapy for the treatment of infections caused by these multidrug-resistant strains. However, the use of VAN has been associated with a high frequency of therapeutic failures in some clinical scenarios, mainly with decreasing concentration of VAN. This work aims to evaluate the synergic potential of VAN plus sulfamethoxazole/trimethoprim (SXT, VAN plus rifampin (RIF and VAN plus imipenem (IPM in sub-minimum inhibitory concentrations against 22 clinical strains of MRSA and CNS. The checkerboard method showed synergism of VAN/RIF and VAN/SXT against two and three of the 22 strains, respectively. The combination of VAN with IPM showed synergistic effects against 21 out of 22 strains by the E-test method. Four strains were analyzed by the time-kill curve method and synergistic activity was observed with VAN/SXT, VAN/RIF and especially VAN/IPM in sub-inhibitory concentrations. It would be interesting to determine if synergy occurs in vivo. Evidence of in vivo synergy could lead to a reduction of the standard VAN dosage or treatment time.

Drug use and antimicrobial resistance among Escherichia coli and Enterococcus spp. isolates from chicken and turkey flocks slaughtered in Quebec, Canada.

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Boulianne, Martine; Arsenault, Julie; Daignault, Danielle; Archambault, Marie; Letellier, Ann; Dutil, Lucie

2016-01-01

An observational study was conducted of chicken and turkey flocks slaughtered at federal processing plants in the province of Quebec, Canada. The objectives were to estimate prevalence of drug use at hatchery and on farm and to identify antimicrobial resistance (AMR) in cecal Escherichia coli and Enterococcus spp. isolates and factors associated with AMR. Eighty-two chicken flocks and 59 turkey flocks were sampled. At the hatchery, the most used antimicrobial was ceftiofur in chickens (76% of flocks) and spectinomycin in turkeys (42% of flocks). Virginiamycin was the antimicrobial most frequently added to the feed in both chicken and turkey flocks. At least 1 E. coli isolate resistant to third-generation cephalosporins was present in all chicken flocks and in a third of turkey flocks. Resistance to tetracycline, streptomycin, and sulfisoxazole was detected in > 90% of flocks for E. coli isolates. Antimicrobial resistance (AMR) was observed to bacitracin, erythromycin, lincomycin, quinupristin-dalfopristin, and tetracycline in both chicken and turkey flocks for Enterococcus spp. isolates. No resistance to vancomycin was observed. The use of ceftiofur at hatchery was significantly associated with the proportion of ceftiofur-resistant E. coli isolates in chicken flocks. In turkey flocks, ceftiofur resistance was more frequent when turkeys were placed on litter previously used by chickens. Associations between drug use and resistance were observed with tetracycline (turkey) in E. coli isolates and with bacitracin (chicken and turkey), gentamicin (turkey), and tylosin (chicken) in Enterococcus spp. isolates. Further studies are needed to provide producers and veterinarians with alternative management practices and tools in order to reduce the use of antimicrobial feed additives in poultry.

Frequency and Treatment of Methicillin Resistant Staphylococcus aureus in Obstetric and Gynaecological Sepsis

International Nuclear Information System (INIS)

Butt, I.J.; Khan, S.; Bhutta, S.; Butt, S.

2013-01-01

Objective: To perform culture and sensitivity for pathogens causing puerperal and postoperative wound sepsis and determine the frequency of Methicillin Resistant Staphylococcus aureus (MRSA) in such infections. Study Design: Observational study. Place and Duration of Study: Obstetrics and Gynaecology Ward, Jinnah Postgraduate Medical Centre, Karachi, from December 2008 to May 2010. Methodology: All patients presenting with puerperal sepsis or postoperative wound infection were enrolled. Pus was collected for culture and sensitivity using standard technique. Two samples were taken from each patient; one before starting the treatment and one at the end of treatment. Ames transport medium was used. Empirical treatment with triple regimen (Ampicillin, Metronidazole and Gentamicin) was started immediately to cover Gram positive as well as negative bacteria in addition to anaerobic infection. After receiving the sensitivity report, antimicrobial agent were changed accordingly. Samples from ward and theater staff and environment were also taken to look for possible mode of transmission. Data was recorded on a proforma. Discrete variables are expressed as percentages. Results: Staphylococcus aureus was the most frequent organism isolated in 34.6% cases. Methicillin sensitive Staphylococcus aureus was seen in 20% cases and methicillin resistant Staphylococcus aureus was seen in 14.6%. Out of these 14.6% MRSA, (17) 77% was associated with puerperal sepsis and rest (5) 23% was associated with postoperative wound infection. It showed best sensitivity to vancomycin. Conclusion: Staphylococcus aureus and E. coli were common causative agent of postoperative infections and puerperal sepsis. (author)

Molecular events for promotion of vancomycin resistance in vancomycin intermediate Staphylococcus aureus

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Qiwen Hu

2016-10-01

Full Text Available Vancomycin has been used as the last resort in the clinical treatment of serious Staphylococcus aureus infections. Vancomycin-intermediate S. aureus (VISA was discovered almost two decades ago. Aside from the vancomycin-intermediate phenotype, VISA strains from the clinic or laboratory exhibited common characteristics, such as thickened cell walls, reduced autolysis, and attenuated virulence. However, the genetic mechanisms responsible for the reduced vancomycin susceptibility in VISA are varied. The comparative genomics of vancomycin-susceptible S. aureus (VSSA/VISA pairs showed diverse genetic mutations in VISA; only a small number of these mutations have been experimentally verified. To connect the diversified genotypes and common phenotypes in VISA, we reviewed the genetic alterations in the relative determinants, including mutation in the vraSRT, graSR, walKR, stk1/stp1, rpoB, clpP, and cmk genes. Especially, we analyzed the mechanism through which diverse mutations mediate vancomycin resistance. We propose a unified model that integrates diverse gene functions and complex biochemical processes in VISA upon the action of vancomycin.

Methicillin-Resistant Staphylococcus aureus nosocomial infection trends in Hospital universiti sains Malasia during 2002-2007

International Nuclear Information System (INIS)

Al-Talib, Hasnain I.; Yean, Chan Y

2010-01-01

Methicillin-resistant staphylococcus aureus (MRSA) is a major nosocomial pathogen that causes severe morbidity and mortality in many hospitals worldwide.The aim of the present study was to assess the burden of MRSA nosocomial infection,its association with factors of interest, and its antimicrobial susceptibility.This was a retrospective analysis of a database of all s aureus that were cultured from patients admitted to the defferent wards of hospital universiti sains malasia(HUSM) over a aperiod of 6 years.The MRSA infections rate was 10.0 Per 1000 hospital admissions.The incidence density rate of MRSA infections during the study period was 1.8 per 1000 patient-days,with annual rates ranging from 0.95 to 3.47 per 1000 patients-days.Duration of hospitalization,previous antibiotic use,and bedside invasive proceures of MRSa infections were found in orthopedic wards (25.3%) followed by surgical wards (18.2%) amd omtensive care units(ICU) (16.4%).All MRSA isolates were resistant to erythromycin (98.0%),co-trimoxazole (94.0%)and gentamicin (92.0%)clindamycin was the best antibiotic with only 6% resistance.All MRSA isolates were sensitive to vancomycin.The rate of the noscomial MRSA infection per 1000 admissions was higher than that in other studies.The three factors associated most signaficantly with acquired MRSA infections included duration of hospitalization,antibiotic use,and bedside invasive procedures.This study confirmed that vancomycin-resistant s aureus has not yet been established in HUSM (Author).

Zinc resistance within swine associated methicillin resistant Staphylococcus aureus (MRSA) isolates in the USA is associated with MLST lineage

Science.gov (United States)

Zinc resistance in livestock-associated methicillin resistant Staphylococcus aureus (LA-MRSA) is mediated by the czrC gene co-located with the mecA gene, encoding methicillin resistance, on the type V SCCmec element. Since the czrC gene and the mecA gene are co-located on the SCCmec element, it has ...

Determination of antibiotic resistance of lactic acid bacteria isolated from traditional Turkish fermented dairy products.

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Erginkaya, Z; Turhan, E U; Tatlı, D

2018-01-01

In this study, the antibiotic resistance (AR) of lactic acid bacteria (LAB) isolated from traditional Turkish fermented dairy products was investigated. Yogurt, white cheese, tulum cheese, cokelek, camız cream and kefir as dairy products were collected from various supermarkets. Lactic acid bacteria such as Lactobacillus spp., Streptococcus spp., Bifidobacterium spp., and Enterecoccus spp. were isolated from these dairy products. Lactobacillus spp. were resistant to vancomycin (58%), erythromycin (10.8%), tetracycline (4.3%), gentamicin (28%), and ciprofloxacin (26%). Streptococcus spp. were resistant to vancomycin (40%), erythromycin (10%), chloramphenicol (10%), gentamicin (20%), and ciprofloxacin (30%). Bifidobacterium spp. were resistant to vancomycin (60%), E 15 (6.6%), gentamicin (20%), and ciprofloxacin (33%). Enterococcus spp. were resistant to vancomycin (100%), erythromycin (100%), rifampin (100%), and ciprofloxacin (100%). As a result, LAB islated from dairy products in this study showed mostly resistance to vancomycin.

Methicillin-resistant staphylococci in animals: epidemiology and interventions

NARCIS (Netherlands)

Verstappen, K.M.H.W.|info:eu-repo/dai/nl/357079485

2017-01-01

Antimicrobial resistance in bacteria is a global problem. Important organisms are methicillin-resistant Staphylococcus aureus (MRSA), which is widespread among pigs, and Staphylococcus pseudintermedius (MRSP), which is an important pathogen in dogs and cats. Infections with these organisms can be

Investigation and Treatment of Fusidic Acid Resistance Among Methicillin-Resistant Staphylococcal Isolates from Egypt.

Science.gov (United States)

Abouelfetouh, Alaa; Kassem, Mervat; Naguib, Marwa; El-Nakeeb, Moustafa

2017-01-01

Methicillin resistance among staphylococci isolated from patients in northern Egypt has escalated alarmingly in the past decade. Data about the prevalence of fusidic acid (FA) resistance in Egyptian clinical isolates are limited. This work investigates the prevalence and mechanism of FA resistance among 81 methicillin-resistant staphylococcal isolates from major hospitals of Alexandria, Egypt. Some combinations for treating infections due to resistant isolates were studied. Twenty-six isolates (32.1%) were FA resistant (minimum inhibitory concentrations [MICs] = 2-1,024 μg/ml), and fusB and fusC genes coding for FA resistance were detected in 30.77% and 34.62% of the FA-resistant strains, respectively. One highly resistant isolate, S502 (MIC = 1,024 μg/ml), possessed both genes. Plasmid curing resulted in fusB loss and MIC decrease by 16-64 folds. Conjugation caused acquisition of FA resistance among susceptible isolates. Serial passages in subinhibitory FA concentrations produced mutants with increased MIC by 4-32 folds. The combination of FA with rifampin, gentamicin, or ampicillin/sulbactam, in a subinhibitory concentration, was synergistic against the isolates, including serial passage mutants, decreasing number of survivors by an average of 2-4 logs. A relatively moderate rate of FA resistance was detected in Alexandria hospitals. Combination therapy with gentamicin, rifampin, or ampicillin/sulbactam is crucial to preserve the effectiveness of FA.

Clinical outcomes of linezolid and vancomycin in patients with nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus stratified by baseline renal function: a retrospective, cohort analysis.

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Liu, Ping; Capitano, Blair; Stein, Amy; El-Solh, Ali A

2017-05-22

The primary objective of this study is to assess whether baseline renal function impacts treatment outcomes of linezolid and vancomycin (with a dose-optimized regimen) for methicillin-resistant Staphylococcus aureus (MRSA) pneumonia. We conducted a retrospective cohort analysis of data generated from a prospective, randomized, controlled clinical trial (NCT 00084266). The analysis included 405 patients with culture-proven MRSA pneumonia. Baseline renal function was stratified based on creatinine clearance. Clinical and microbiological success rates and presence of nephrotoxicity were assessed at the end of treatment (EOT) and end of study (EOS). Multivariate logistic regression analyses of baseline patient characteristics, including treatment, were performed to identify independent predictors of efficacy. Vancomycin concentrations were analyzed using a nonlinear mixed-effects modeling approach. The relationships between vancomycin exposures, pharmacokinetic-pharmacodynamic index (trough concentration, area under the curve over a 24-h interval [AUC 0-24 ], and AUC 0-24 /MIC) and efficacy/nephrotoxicity were assessed in MRSA pneumonia patients using univariate logistic regression or Cox proportional hazards regression analysis approach. After controlling for use of vasoactive agents, choice of antibiotic therapy and bacteremia, baseline renal function was not correlated with clinical and microbiological successes in MRSA pneumonia at either end of treatment or at end of study for both treatment groups. No positive association was identified between vancomycin exposures and efficacy in these patients. Higher vancomycin exposures were correlated with an increased risk of nephrotoxicity (e.g., hazards ratio [95% confidence interval] for a 5 μg/ml increase in trough concentration: 1.42 [1.10, 1.82]). In non-dialysis patients, baseline renal function did not impact the differences in efficacy or nephrotoxicity with treatment of linezolid versus vancomycin in MRSA

Methicillin-resistant Staphylococcus sp. colonizing health care workers of a cancer hospital

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Costa, Dayane de Melo; Kipnis, André; Leão-Vasconcelos, Lara Stefânia Netto de Oliveira; Rocha-Vilefort, Larissa Oliveira; Telles, Sheila Araújo; André, Maria Cláudia Dantas Porfírio Borges; Tipple, Anaclara Ferreira Veiga; Lima, Ana Beatriz Mori; Ribeiro, Nádia Ferreira Gonçalves; Pereira, Mayara Regina; Prado-Palos, Marinésia Aparecida

2014-01-01

The aim of the study was to analyze epidemiological and microbiological aspects of oral colonization by methicillin-resistant Staphylococcus of health care workers in a cancer hospital. Interview and saliva sampling were performed with 149 health care workers. Antimicrobial resistance was determined by disk diffusion and minimum inhibitory concentration. Polymerase Chain Reaction, Internal Transcribed Spacer-Polymerase Chain Reaction and Pulsed Field Gel Electrophoresis were performed for genotypic characterization of methicillin-resistant Staphylococcus. Risk factors were determined by logistic regression. Methicillin-resistant Staphylococcus colonization prevalence was 19.5%, denture wearing (p = 0.03), habit of nail biting (p = 0.04) and preparation and administration of antimicrobial (p = 0.04) were risk factors identified. All methicillin-resistant Staphylococcus were S. epidermidis, 94.4% of them had mecA gene. Closely related and indistinguishable methicillin-resistant S. epidermidis were detected. These results highlight that HCWs which have contact with patient at high risk for developing infections were identified as colonized by MRSE in the oral cavity, reinforcing this cavity as a reservoir of these bacteria and the risk to themselves and patients safety, because these microorganisms may be spread by coughing and talking. PMID:25477910

Concurrent infectious mononucleosis and community-associated methicillin-resistant Staphylococcus aureus bacteremia.

Science.gov (United States)

Wang, Li Jun; Du, Xiao Qin; Nyirimigabo, Eric; Shou, Song Tao

2014-04-01

It is rare to see a concurrent infection with infectious mononucleosis and community-associated methicillin-resistant Staphylococcus aureus in Tianjin, China. Until now, there is still no any single recorded case of concurrent infectious mononucleosis and community-associated methicillin-resistant Staphylococcus aureus bacteremia.

Quality Control of Direct Molecular Diagnostics for Methicillin-Resistant Staphylococcus aureus▿

Science.gov (United States)

van Belkum, Alex; Niesters, Hubert G. M.; MacKay, William G.; van Leeuwen, Willem B.

2007-01-01

Ten samples containing various amounts of methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible S. aureus, methicillin-resistant Staphylococcus epidermidis (MRSE), and combinations thereof were distributed to 51 laboratories for molecular diagnostics testing. Samples containing 102 to 103 MRSA cells were frequently reported to be negative. MRSE samples were scored as negative by all commercial tests but by only two out of three in-house tests. PMID:17581936

Root cause analysis of methicillin resistant Staphylococcus aureus bacteraemia.

Science.gov (United States)

Aslam, Nadia; Mehdi, Naima; Izhar, Mateen

2015-10-01

To find the important risk factors and sources of bacteraemia in patients suffering from methicillin-resistant staphylococcus aureus bacteraemia. The descriptive study was carried out at Shaikh Zayed Hospital, Lahore, from October 2010 to August 2011. Blood cultures were processed to isolate methicillin-resistant staphylococcus aureus. A questionnaire was completed by the participating patients suffering from bacteraemia. Information about risk factors present at the time and risk factors that served as the source of bacteraemia were noted. Total 4058 blood cultures were processed and 669(16.5%) were positive. Of them, 194(29%) cultures were found to be positive for staphylococci. Out of these 194 blood cultures, coagulase-negative staphylococci were isolated from 117(60%), and 77(40%) were positive for S. aureus. Out of these 77 samples, 26(34%) were found to be methicillin-sensitive staphylococcus aureus and 51(66%) were methicillin-resistant staphylococcus aureus. The overall frequency of methicillin-resistant staphylococcus aureus was 1.25%; 7.62% out of positive blood culture; 26.28% out of total staphylococci; and 66% out of total S. aureus. As for the source of infection, central venous pressure line 11(21.6%), post-influenza pneumonia 9(17.6%), peripheral intravenous line 8(15.7%) and dialysis line 7(13.7%) were major reasons. Taking care of aseptic measures while insertion, frequent change and early removal of the central venous and dialysis lines is of critical significance.

Characterization and susceptibility patterns of clinically important Enterococcus species in eastern Nepal.

Science.gov (United States)

Acharya, A; Khanal, A; Kanungo, R; Mohapatra, T

2007-12-01

Life threatening infections caused by enterococcus species with multidrug resistance has emerged as a threat to medical care in the present era. This study was conducted to characterize enterococcus species isolated from different clinical samples and to detect the pattern of susceptibility to some of the commonly used antibiotics in B.P Koirala Institute of Health Sciences (BPKIHS), a tertiary care hospital in eastern Nepal. Clinical samples submitted to the microbiology unit of Central Laboratory Service (CLS) for culture and sensitivity during March 2002 - February 2003 was analyzed. Enterococcus species were identified by colony characteristics, gram staining and relevant biochemical tests. Antibiotic susceptibility test was done by the Kirby Bauer disc diffusion technique. Of 50 Enterococcus species isolated, E. faecalis was the predominant isolate (48.0%) followed by E. faecium (32.0%) and E. avium (20.0%). Eighty-eight percent of E. faecalis showed sensitivity to cephotaxime and 87.0% to vancomycin. Multiple drug resistance was observed most commonly in E. faecium. Seventeen percent of E. faecium were resistant to vancomycin and 63.0% to ciprofloxacin and 44.0% to ampicillin. On the contrary E. avium rarely showed resistance to the antimicrobials tested including vancomycin. Enterococcal infections are common nowadays specially in hospitalized patients. Inappropriate use of antibiotics in clinical practice and poultry should be discouraged to prevent the emergence of multidrug resistant species.

Antimicrobial Susceptibility Patterns of Enterococcus faecalis and Enterococcus faecium Isolated from Poultry Flocks in Germany.

Science.gov (United States)

Maasjost, J; Mühldorfer, K; Cortez de Jäckel S; Hafez, H M

2015-03-01

Between 2010 and 2011, 145 Enterococcus isolates (Enterococcus faecalis, n = 127; Enterococcus faecium, n = 18) were collected during routine bacteriologic diagnostics from broilers, layers, and fattening turkeys in Germany showing various clinical signs. The susceptibility to 24 antimicrobial agents was investigated by broth microdilution test to determine minimum inhibitory concentrations (MICs). All E. faecalis isolates (n = 127) were susceptible to the beta-lactam antibiotics ampicillin, amoxicillin-clavulanic acid, and penicillin. Corresponding MIC with 50% inhibition (MIC50) and MIC with 90% inhibition (MIC90) values of these antimicrobial agents were at the lower end of the test range (≤ 4 μg/ml). In addition, no vancomycin-resistant enterococci (VRE) were found. High resistance rates were identified in both Enterococcus species for lincomycin (72%-99%) and tetracycline (67%-82%). Half or more than half of Enterococcus isolates were resistant to gentamicin (54%-72%) and the macrolide antibiotics erythromycin (44%-61%) and tylosin-tartate (44%-56%). Enterococcus faecalis isolated from fattening turkeys showed the highest prevalence of antimicrobial resistance compared to other poultry production systems. Eighty-nine out of 145 Enterococcus isolates were resistant to three or more antimicrobial classes. Again, turkeys stood out with 42 (8 1%) multiresistant isolates. The most-frequent resistance patterns of E. faecalis were gentamicin, lincomycin, and tetracycline in all poultry production systems.

Effect of nosocomial vancomycin-resistant enterococcal bacteremia on mortality, length of stay, and costs.

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Song, Xiaoyan; Srinivasan, Arjun; Plaut, David; Perl, Trish M

2003-04-01

To determine the impact of vancomycin-resistant enterococcal bacteremia on patient outcomes and costs by assessing mortality, excess length of stay, and charges attributable to it. A population-based, matched, historical cohort study. A 1,025-bed, university-based teaching facility and referral hospital. Two hundred seventy-seven vancomycin-resistant enterococcal bacteremia case-patients and 277 matched control-patients identified between 1993 and 2000. The crude mortality rate was 50.2% and 19.9% for case-patients and control-patients, respectively, yielding a mortality rate of 30.3% attributable to vancomycin-resistant enterococcal bacteremia. The excess length of hospital stay attributable to vancomycin-resistant enterococcal bacteremia was 17 days, of which 12 days were spent in intensive care units. On average, dollars 77,558 in extra charges was attributable to each vancomycin-resistant enterococcal bacteremia. To adjust for severity of illness, 159 pairs of case-patients and control-patients, who had the same severity of illness (All Patient Refined-Diagnosis Related Group complexity level), were further analyzed. When patients were stratified by severity of illness, the crude mortality rate was 50.3% among case-patients compared with 27.7% among control-patients, accounting for an attributable mortality rate of 22.6%. Attributable excess length of stay and charges were 17 days and dollars 81,208, respectively. Vancomycin-resistant enterococcal bacteremia contributes significantly to excess mortality and economic loss, once severity of illness is considered. Efforts to prevent these infections will likely be cost-effective.

Ceftaroline fosamil: a cephalosporin with activity against methicillin-resistant Staphylococcus aureus.

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Poon, Henry; Chang, Mei H; Fung, Horatio B

2012-04-01

pharmacokinetic properties of ceftaroline in patients with hepatic impairments are currently unavailable. Ceftaroline appeared to be well tolerated generally. The most frequently (>3%) reported adverse events were nausea, headaches, diarrhea, pruritus, rash, and insomnia; all were usually mild to moderate, self-limiting, and of little clinical significance. Ceftaroline is a cephalosporin with broad gram-positive activity, including Methicillin-resistant S aureus and vancomycin-resistant S aureus. Its gram-negative activity includes common respiratory pathogens and members of the Enterobacteriaceae. Clinical trials have reported that ceftaroline was noninferior to ceftriaxone, and vancomycin + aztreonam for the treatment of community-acquired pneumonia and complicated skin and skin-structure infections, respectively. Published by EM Inc USA.

Impact of an Environmental Cleaning Intervention on the Presence of Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococci on Surfaces in Intensive Care Unit Rooms

Science.gov (United States)

Goodman, Eric R.; Platt, Richard; Bass, Richard; Onderdonk, Andrew B.; Yokoe, Deborah S.; Huang, Susan S.

2009-01-01

OBJECTIVES To evaluate the adequacy of discharge room cleaning and the impact of a cleaning intervention on the presence of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) on environmental surfaces in intensive care unit (ICU) rooms. DESIGN Prospective environmental study. SETTING AND SAMPLE Convenience sample of ICU rooms in an academic hospital. METHODS AND INTERVENTION The intervention consisted of (1) a change from the use of pour bottles to bucket immersion for applying disinfectant to cleaning cloths, (2) an educational campaign, and (3) feedback regarding adequacy of discharge cleaning. Cleaning of 15 surfaces was evaluated by inspecting for removal of a preapplied mark, visible only with an ultraviolet lamp (“black light”). Six surfaces were cultured for MRSA or VRE contamination. Outcomes of mark removal and culture positivity were evaluated by χ2 testing and generalized linear mixed models, clustering by room. RESULTS The black-light mark was removed from 44% of surfaces at baseline, compared with 71% during the intervention (P <.001). The intervention increased the likelihood of removal of black-light marks after discharge cleaning (odds ratio, 4.4; P < .001), controlling for ICU type (medical vs surgical) and type of surface. The intervention reduced the likelihood of an environmental culture positive for MRSA or VRE (proportion of cultures positive, 45% at baseline vs 27% during the intervention; adjusted odds ratio, 0.4; P = .02). Broad, flat surfaces were more likely to be cleaned than were doorknobs and sink or toilet handles. CONCLUSIONS Increasing the volume of disinfectant applied to environmental surfaces, providing education for Environmental Services staff, and instituting feedback with a black-light marker improved cleaning and reduced the frequency of MRSA and VRE contamination. PMID:18624666

Modified DNA extraction for rapid PCR detection of methicillin-resistant staphylococci

International Nuclear Information System (INIS)

Japoni, A.; Alborzi, A.; Rasouli, M.; Pourabbas, B.

2004-01-01

Nosocomial infection caused by methicillin-resistant staphylococci poses a serious problem in many countries. The aim of this study was to rapidly and reliably detect methicillin-resistant-staphylococci in order to suggest appropriate therapy. The presence or absence of the methicillin-resistance gene in 115 clinical isolates of staphylococcus aureus and 50 isolates of coagulase negative staphylococci was examined by normal PCR. DNA extraction for PCR performance was then modified by omission of achromopeptadiase and proteinase K digestion, phenol/chloroform extraction and ethanol precipitation. All isolates with Mic>8 μ g/ml showed positive PCR. No differences in PCR detection have been observed when normal and modified DNA extractions have been performed. Our modified DNA extraction can quickly detect methicillin-resistant staphylococci by PCR. The advantage of rapid DNA extraction extends to both reduction of time and cost of PCR performance. This modified DNA extraction is suitable for different PCR detection, when staphylococci are the subject of DNA analysis

Origins and Evolution of Methicillin-Resistant Staphylococcus aureus Clonal Lineages

DEFF Research Database (Denmark)

Gomes, AR; Westh, Henrik; Lancastre, H de

2006-01-01

Most methicillin-resistant Staphylococcus aureus (MRSA) isolates identified among blood isolates collected in Denmark between 1957 and 1970 belonged to either phage group III or the closely related 83A complex and had a PSTM antibiotype (resistance to penicillin [P], streptomycin [S], tetracycline...... [T], and methicillin [M]). Recently, some of these isolates were shown to have the same genetic backgrounds as contemporary epidemic MRSA isolates, and Danish methicillin-susceptible S. aureus (MSSA) isolates from the 1960s with a PST antibiotype were proposed to have been the recipients of the mec...

Cell Wall Remodeling by a Synthetic Analog Reveals Metabolic Adaptation in Vancomycin Resistant Enterococci.

Science.gov (United States)

Pidgeon, Sean E; Pires, Marcos M

2017-07-21

Drug-resistant bacterial infections threaten to overburden our healthcare system and disrupt modern medicine. A large class of potent antibiotics, including vancomycin, operate by interfering with bacterial cell wall biosynthesis. Vancomycin-resistant enterococci (VRE) evade the blockage of cell wall biosynthesis by altering cell wall precursors, rendering them drug insensitive. Herein, we reveal the phenotypic plasticity and cell wall remodeling of VRE in response to vancomycin in live bacterial cells via a metabolic probe. A synthetic cell wall analog was designed and constructed to monitor cell wall structural alterations. Our results demonstrate that the biosynthetic pathway for vancomycin-resistant precursors can be hijacked by synthetic analogs to track the kinetics of phenotype induction. In addition, we leveraged this probe to interrogate the response of VRE cells to vancomycin analogs and a series of cell wall-targeted antibiotics. Finally, we describe a proof-of-principle strategy to visually inspect drug resistance induction. Based on our findings, we anticipate that our metabolic probe will play an important role in further elucidating the interplay among the enzymes involved in the VRE biosynthetic rewiring.

Identification of putative drug targets in Vancomycin-resistant Staphylococcus aureus (VRSA) using computer aided protein data analysis.

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Hasan, Md Anayet; Khan, Md Arif; Sharmin, Tahmina; Hasan Mazumder, Md Habibul; Chowdhury, Afrin Sultana

2016-01-01

Vancomycin-resistant Staphylococcus aureus (VRSA) is a Gram-positive, facultative aerobic bacterium which is evolved from the extensive exposure of Vancomycin to Methicillin resistant S. aureus (MRSA) that had become the most common cause of hospital and community-acquired infections. Due to the emergence of different antibiotic resistance strains, there is an exigency to develop novel drug targets to address the provocation of multidrug-resistant bacteria. In this study, in-silico genome subtraction methodology was used to design potential and pathogen specific drug targets against VRSA. Our study divulged 1987 proteins from the proteome of 34,549 proteins, which have no homologues in human genome after sequential analysis through CD-HIT and BLASTp. The high stringency analysis of the remaining proteins against database of essential genes (DEG) resulted in 169 proteins which are essential for S. aureus. Metabolic pathway analysis of human host and pathogen by KAAS at the KEGG server sorted out 19 proteins involved in unique metabolic pathways. 26 human non-homologous membrane-bound essential proteins including 4 which were also involved in unique metabolic pathway were deduced through PSORTb, CELLO v.2.5, ngLOC. Functional classification of uncharacterized proteins through SVMprot derived 7 human non-homologous membrane-bound hypothetical essential proteins. Study of potential drug target against Drug Bank revealed pbpA-penicillin-binding protein 1 and hypothetical protein MQW_01796 as the best drug target candidate. 2D structure was predicted by PRED-TMBB, 3D structure and functional analysis was also performed. Protein-protein interaction network of potential drug target proteins was analyzed by using STRING. The identified drug targets are expected to have great potential for designing novel drugs against VRSA infections and further screening of the compounds against these new targets may result in the discovery of novel therapeutic compounds that can be

Prevalence and antibiogram of methicillin resistant Staphylococcus aureus isolated from medical device-related infections; a retrospective study in Lahore, Pakistan

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Muhammad Sohail

Full Text Available Abstract INTRODUCTION: With the advancement of medicine and surgery, various types of medical devices have become part of treatment strategies. METHODS: Identification and antimicrobial sensitivity testing were done according to CLSI guidelines following standard microbiological practices. RESULTS: Urinary catheter infections (31% were most frequent followed by central venous catheter (18% and orthopedic implants (15%. Methicillin resistant Staphylococcus aureus (MRSA was a major cause of device-related infection after Escherichia coli (21%; other pathogens were Klebsiella pneumoniae (14%, Pseudomonas spp. (10%, Acinetobacter spp. (8% and Candida species (7%. None of MRSA was resistant to vancomycin (MIC ≥16µg/mL. Resistance rates were 98% and 97% for ofloxacin and ciprofloxacin, respectively. CONCLUSIONS Escherichia coli and MRSA are major pathogens of medical device-related infections.

Multidrug resistance in Enterococcus species of faecal origin from commercial dairy lactating cattle: Public health concern

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Godfred Ngu Tanih

2017-11-01

Full Text Available Objective: To evaluate the prevalence of Enterococcus species in cattle faeces, their corresponding drug resistant patterns as well as the genes coding for resistance in the isolates. Methods: Two hundred and ninety rectal swabs were cultured for the isolation of Enterococcus. Presumptive isolates were confirmed by PCR, targeting the tuf gene, and confirmed isolates were identified to species level, using species-specific primers aimed at targeting six different species. Additionally, antibiogram was performed by disc diffusion and genes implicated in resistance were evaluated using molecular methods. Results: All presumptive isolates were confirmed as Enterococcus and speciated as: Enterococcus hirae (82%, Enterococcus faecium (5%, Enterococcus durans (5%, Enterococcus faecalis (2% and 6% of unidentified species. Resistance to various antimicrobials ranged from 16.4% for penicillin to 69.6% for erythromycin. Among the tetracycline and erythromycin-resistant isolates, tet M (100% and erm B (29% were the only amplified genes known to mediate resistance respectively. Other detected genes included van B (25%, van C1 (21% and bla Z (11%. Conclusions: A high prevalence of multidrug resistant Enterococcus species was observed in this study, accentuating the need to improve on animal farming practices to prevent the dissemination of this microorganism to the environment.

Persistence of Vancomycin Resistance in Multiple Clones of Enterococcus faecium Isolated from Danish Broilers 15 Years after the Ban of Avoparcin

DEFF Research Database (Denmark)

Bortolaia, Valeria; Mander, Manuela; Jensen, Lars Bogø

2015-01-01

associated with a transferable nontypeable plasmid lineage occurring in multiple E. faecium clones. Coselection of sequence type 842 by tetracycline use only partly explained the persistence of vancomycin resistance in the absence of detectable plasmid coresistance and toxin-antitoxin systems....

An Outbreak of Vancomycin-Resistant Enterococcus faecium in an Acute Care Pediatric Hospital: Lessons from Environmental Screening and a Case-Control Study

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Steven J Drews

2008-01-01

Full Text Available BACKGROUND: The present study describes a vancomycin-resistant enterococci (VRE outbreak investigation and a case-control study to identify risk factors for VRE acquisition in a tertiary care pediatric hospital.

Growth Behavior of E. coli, Enterococcus and Staphylococcus Species in the Presence and Absence of Sub-inhibitory Antibiotic Concentrations: Consequences for Interpretation of Culture-Based Data.

Science.gov (United States)

Heß, Stefanie; Gallert, Claudia

2016-11-01

Culture-based approaches are used to monitor, e.g., drinking water or bathing water quality and to investigate species diversity and antibiotic resistance levels in environmental samples. For health risk assessment, it is important to know whether the growing cultures display the actual abundance of, e.g., clinically relevant antibiotic resistance phenotypes such as vancomycin-resistant Enterococcus faecium/Enterococcus faecalis (VRE) or methicillin-resistant Staphylococcus aureus. In addition, it is important to know whether sub-inhibitory antibiotic concentrations, which are present in surface waters, favor the growth of antibiotic-resistant strains. Therefore, clinically relevant bacteria were isolated from different water sources and the growth behavior of 58 Escherichia coli, 71 Enterococcus, and 120 Staphylococcus isolates, belonging to different species and revealing different antibiotic resistance patterns, was studied with respect to "environmental" antibiotic concentrations. The finding that VRE could only be detected after specific enrichment can be explained by their slow growth compared to non-resistant strains. Interpreting their absence in standardized culture-based methods as nonexistent might be a fallacy. Sub-inhibitory antibiotic concentrations that were detected in sewage and receiving river water did not specifically promote antibiotic-resistant strains. Generally, those antibiotics that influenced cell metabolism directly led to slightly reduced growth rates and less than maximal optical densities after 48 h of incubation.

Carriage of methicillin-resistant Staphylococcus pseudintermedius in small animal veterinarians

DEFF Research Database (Denmark)

Paul, Narayan Chandra; Moodley, Arshnee; Ghibaudo, G.

2011-01-01

Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is increasingly reported in small animals and cases of human infections have already been described despite its recent emergence in veterinary practice. We investigated the prevalence of MRSP and methicillin-resistant Staphylococcus...... aureus (MRSA) among small animal dermatologists attending a national veterinary conference in Italy. Nasal swabs were obtained from 128 veterinarians, seven of which harboured MRSP (n = 5; 3.9%) or MRSA (n = 2; 1.6%). A follow-up study of two carriers revealed that MRSP persisted for at least 1 month...... by spa typing. Methicillin-resistant isolates were further typed by antimicrobial susceptibility testing, SCCmec and multi-locus sequence typing. Two lineages previously associated with pets were identified among the five MRSP isolates; the European epidemic clone ST71-SCCmec II-III and ST106-SCCmec IV...

Phage therapy against Enterococcus faecalis in dental root canals

OpenAIRE

Khalifa, Leron; Shlezinger, Mor; Beyth, Shaul; Houri-Haddad, Yael; Coppenhagen-Glazer, Shunit; Beyth, Nurit; Hazan, Ronen

2016-01-01

Antibiotic resistance is an ever-growing problem faced by all major sectors of health care, including dentistry. Recurrent infections related to multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus, carbapenem-resistant Enterobacteriaceae, and vancomycin-resistant enterococci (VRE) in hospitals are untreatable and question the effectiveness of notable drugs. Two major reasons for these recurrent infections are acquired antibiotic resistance genes and biofilm format...

Titanium-tethered vancomycin prevents resistance to rifampicin in Staphylococcus aureus in vitro.

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Martin Rottman

Full Text Available Rifampicin is currently recognized as the most potent drug against Gram positive implant related infections. The use of rifampicin is limited by the emergence of bacterial resistance, which is often managed by coadministration of a second antibiotic. The purpose of this study was to determine the effectiveness of soluble rifampicin in combination with vancomycin tethered to titanium metal as a means to control bacterial growth and resistance in vitro. Bacterial growth was inhibited when the vancomycin-tethered titanium discs were treated with Staphylococcus aureus inocula of ≤2×10⁶ CFU, however inocula greater than 2×10⁶ CFU/disc adhered and survived. The combination of surface-tethered vancomycin with soluble rifampicin enhanced the inhibitory effect of rifampicin for an inoculum of 10⁶ CFU/cm² by one dilution (combination MIC of 0.008 mg/L versus 0.015 mg/L for rifampicin alone. Moreover, surface tethered vancomycin prevented the emergence of a rifampicin resistant population in an inoculum of 2×10⁸ CFU.

Bacillus subtilis as a platform for molecular characterisation of regulatory mechanisms of Enterococcus faecalis resistance against cell wall antibiotics.

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Fang, Chong; Stiegeler, Emanuel; Cook, Gregory M; Mascher, Thorsten; Gebhard, Susanne

2014-01-01

To combat antibiotic resistance of Enterococcus faecalis, a better understanding of the molecular mechanisms, particularly of antibiotic detection, signal transduction and gene regulation is needed. Because molecular studies in this bacterium can be challenging, we aimed at exploiting the genetically highly tractable Gram-positive model organism Bacillus subtilis as a heterologous host. Two fundamentally different regulators of E. faecalis resistance against cell wall antibiotics, the bacitracin sensor BcrR and the vancomycin-sensing two-component system VanSB-VanRB, were produced in B. subtilis and their functions were monitored using target promoters fused to reporter genes (lacZ and luxABCDE). The bacitracin resistance system BcrR-BcrAB of E. faecalis was fully functional in B. subtilis, both regarding regulation of bcrAB expression and resistance mediated by the transporter BcrAB. Removal of intrinsic bacitracin resistance of B. subtilis increased the sensitivity of the system. The lacZ and luxABCDE reporters were found to both offer sensitive detection of promoter induction on solid media, which is useful for screening of large mutant libraries. The VanSB-VanRB system displayed a gradual dose-response behaviour to vancomycin, but only when produced at low levels in the cell. Taken together, our data show that B. subtilis is a well-suited host for the molecular characterization of regulatory systems controlling resistance against cell wall active compounds in E. faecalis. Importantly, B. subtilis facilitates the careful adjustment of expression levels and genetic background required for full functionality of the introduced regulators.

Comparison of vancomycin and linezolid in patients with peripheral vascular disease and/or diabetes in an observational European study of complicated skin and soft-tissue infections due to methicillin-resistant Staphylococcus aureus.

Science.gov (United States)

Eckmann, C; Nathwani, D; Lawson, W; Corman, S; Solem, C; Stephens, J; Macahilig, C; Li, J; Charbonneau, C; Baillon-Plot, N; Haider, S

2015-09-01

Suboptimal antibiotic penetration into soft tissues can occur in patients with poor circulation due to peripheral vascular disease (PVD) or diabetes. We conducted a real-world analysis of antibiotic treatment, hospital resource use and clinical outcomes in patients with PVD and/or diabetes receiving linezolid or vancomycin for the treatment of methicillin-resistant Staphylococcus aureus complicated skin and soft-tissue infections (MRSA cSSTIs) across Europe. This subgroup analysis evaluated data obtained from a retrospective, observational medical chart review study that captured patient data from 12 European countries. Data were obtained from the medical records of patients ≥ 18 years of age, hospitalized with an MRSA cSSTI between 1 July 2010 and 30 June 2011 and discharged alive by 31 July 2011. Hospital length of stay and length of treatment were compared between the treatment groups using inverse probability of treatment weights to adjust for clinical and demographic differences. A total of 485 patients had PVD or diabetes and received treatment with either vancomycin (n = 258) or linezolid (n = 227). After adjustment, patients treated with linezolid compared with vancomycin respectively had significantly shorter hospital stays (17.9 ± 13.6 vs. 22.6 ± 13.6 days; p linezolid and vancomycin groups, respectively (p linezolid compared with vancomycin. Copyright © 2015. Published by Elsevier Ltd.

Increasing trend of community-acquired methicillin-resistant: Staphylococcal carriers: An alarming bell for urgent measures

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Poongodi Lakshmi Santhana Kumarasamy

2015-01-01

Full Text Available Background: An increase in the incidence of infections caused by community-associated-methicillin resistant Staphylococcus aureus (MRSA has been reported. Hence, the knowledge of resistance pattern of these isolates is a precondition for alleviating emerging antibiotic resistance and devising better treatment strategies Aim: To find out the prevalence of community-acquired methicillin-resistant staphylococcal strains from nasal carriers. Materials and Methods: A total of 352 nasal swabs collected during routine health checkup were analyzed. Results: Of the 58 (16% staphylococci isolated, 32 (55% were S. aureus and 26 (45% were coagulase-negative staphylococci (CoNS. Methicillin resistance was observed in 7 (22% of staphylococci aureus and 11 (42% of CoNS. "D test" was positive in 1 (14% MRSA, 2 (8% methicillin-susceptible S. aureus and 2 (8% methicillin resistant-CoNS. Conclusion: Effective implementation of the antibiotic policy along with measures like hand wash, isolation of patients will reduce the incidence of resistance.

Phenotypic occurrence of methicillin-resistant Staphylococcus ...

African Journals Online (AJOL)

To assess the occurrence of MRSA among camels in Kano abattoir, a total of 300 nasal swabs were collected from camels at the lairage in Kano abattoir, Kano state, Nigeria to isolate and biochemically characterize Staphylococcus aureus and confirm methicillin-resistant Staphylococcus aureus among isolates using ...

Nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus treated with linezolid or vancomycin: A secondary economic analysis of resource use from a Spanish perspective.

Science.gov (United States)

Rello, J; Nieto, M; Solé-Violán, J; Wan, Y; Gao, X; Solem, C T; De Salas-Cansado, M; Mesa, F; Charbonneau, C; Chastre, J

2016-11-01

Adopting a unique Spanish perspective, this study aims to assess healthcare resource utilization (HCRU) and the costs of treating nosocomial pneumonia (NP) produced by methicillin-resistant Staphylococcus aureus (MRSA) in hospitalized adults using linezolid or vancomycin. An evaluation is also made of the renal failure rate and related economic outcomes between study groups. An economic post hoc evaluation of a randomized, double-blind, multicenter phase 4 study was carried out. Nosocomial pneumonia due to MRSA in hospitalized adults. The modified intent to treat (mITT) population comprised 224 linezolid- and 224 vancomycin-treated patients. Costs and HCRU were evaluated between patients administered either linezolid or vancomycin, and between patients who developed renal failure and those who did not. Analysis of HCRU outcomes and costs. Total costs were similar between the linezolid- (€17,782±€9,615) and vancomycin-treated patients (€17,423±€9,460) (P=.69). The renal failure rate was significantly lower in the linezolid-treated patients (4% vs. 15%; Prenal failure (€19,626±€10,840 vs. €17,388±€9,369; P=.14). Among the patients who developed renal failure, HCRU (days on mechanical ventilation: 13.2±10.7 vs. 7.6±3.6 days; P=.21; ICU stay: 14.4±10.5 vs. 9.9±6.6 days; P=.30; hospital stay: 19.5±9.5 vs. 16.1±11.0 days; P=.26) and cost (€17,219±€8,792 vs. €20,263±€11,350; P=.51) tended to be lower in the linezolid- vs. vancomycin-treated patients. There were no statistically significant differences in costs per patient-day between cohorts after correcting for mortality (€1000 vs. €1,010; P=.98). From a Spanish perspective, there were no statistically significant differences in total costs between the linezolid and vancomycin pneumonia cohorts. The drug cost corresponding to linezolid was partially offset by fewer renal failure adverse events. Copyright © 2016 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

Production of low-affinity penicillin-binding protein by low- and high-resistance groups of methicillin-resistant Staphylococcus aureus.

Science.gov (United States)

Murakami, K; Nomura, K; Doi, M; Yoshida, T

1987-01-01

Methicillin- and cephem-resistant Staphylococcus aureus (137 strains) for which the cefazolin MICs are at least 25 micrograms/ml could be classified into low-resistance (83% of strains) and high-resistance (the remaining 17%) groups by the MIC of flomoxef (6315-S), a 1-oxacephalosporin. The MICs were less than 6.3 micrograms/ml and more than 12.5 micrograms/ml in the low- and high-resistance groups, respectively. All strains produced penicillin-binding protein 2' (PBP 2'), which has been associated with methicillin resistance and which has very low affinity for beta-lactam antibiotics. Production of PBP 2' was regulated differently in low- and high-resistance strains. With penicillinase-producing strains of the low-resistance group, cefazolin, cefamandole, and cefmetazole induced PBP 2' production about 5-fold, while flomoxef induced production 2.4-fold or less. In contrast, penicillinase-negative variants of low-resistance strains produced PBP 2' constitutively in large amounts and induction did not occur. With high-resistance strains, flomoxef induced PBP 2' to an extent similar to that of cefazolin in both penicillinase-producing and -negative strains, except for one strain in which the induction did not occur. The amount of PBP 2' induced by beta-lactam antibiotics in penicillinase-producing strains of the low-resistance group correlated well with resistance to each antibiotic. Large amounts of PBP 2' in penicillinase-negative variants of the low-resistance group did not raise the MICs of beta-lactam compounds, although these strains were more resistant when challenged with flomoxef for 2 h. Different regulation of PBP 2' production was demonstrated in the high- and low-resistance groups, and factor(s) other than PBP 2' were suggested to be involved in the methicillin resistance of high-resistance strains. Images PMID:3499861

In Vitro Synergy of Telavancin and Rifampin Against Enterococcus faecium Resistant to Both Linezolid and Vancomycin.

Science.gov (United States)

Pankey, George A; Ashcraft, Deborah S

2013-01-01

An emerging pathogen is Enterococcus faecium resistant to both linezolid and vancomycin (LRVRE). Antimicrobial combinations may be required for therapy and need to be evaluated. The combination of daptomycin and rifampin has demonstrated good in vitro activity against gram-positive bacteria, including E faecium. Telavancin, a newer lipoglycopeptide, has shown in vitro activity against E faecium. We evaluated the combination of telavancin and rifampin and compared the results to the combination of daptomycin and rifampin used previously on the same isolates. Twenty-four genetically unique (by pulsed-field gel electrophoresis), clinical LRVRE isolates were collected in the United States from 2001-2004. Etest minimal inhibitory concentrations (MICs) (μg/mL) were 0.064-8 for telavancin, 1-4 for daptomycin, and 0.012 to >32 for rifampin. In vitro synergy testing was performed in triplicate by an Etest MIC:MIC ratio method, and summation fractional inhibitory concentration (ΣFIC) was calculated: synergy ≤0.5; indifference >0.5-4; and antagonism >4. The Etest method showed synergy (ΣFICs of 0.1-0.5) with telavancin + rifampin in 20/24 (83%) isolates and indifference (ΣFICs of 0.6-0.8) in 4/24 (17%) isolates. Similarly, the daptomycin + rifampin combination showed synergy (ΣFICs of 0.1-0.5) in 21/24 (88%) isolates and indifference (ΣFICs of 0.6-1.0) in 3/24 (12%) isolates by the Etest method. No antagonism was found. In vitro synergy with both combinations (rifampin + telavancin or daptomycin) was 83% and 88%, respectively, by Etest against these LRVRE isolates. Although both daptomycin and telavancin in combination with rifampin showed a high incidence of synergistic activity, further in vitro synergy testing with this combination should be performed against additional E faecium isolates. In vitro synergy may or may not translate into in vivo effectiveness.

Prevalence of Methicillin-Resistant Staphylococcus aureus and Other Staphylococcus Species in Raw Meat Samples Intended for Human Consumption in Benin City, Nigeria: Implications for Public Health.

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Igbinosa, Etinosa O; Beshiru, Abeni; Akporehe, Lucy U; Oviasogie, Faith E; Igbinosa, Owen O

2016-09-24

The present study was designed to characterize methicillin-resistant staphylococci from raw meat. A total of 126 meat samples were obtained from open markets between February and April, 2015. Antimicrobial susceptibility testing was carried out using the disc diffusion method. Molecular profiling was conducted using 16S rRNA, mecA, nuc, and PVL gene signatures were detected by polymerase chain reaction assay. Fifty isolates of methicillin-resistant Staphylococcus spp. were detected in 26 (52%) pork, 14 (28%) beef and 10 (20%) chicken samples. The staphylococcal isolates were identified through partial 16S ribosomal ribonucleic acid (16S rRNA) nucleotide sequencing, and BLAST analysis of the gene sequence revealed 98%-100% staphylococcal similarity. All isolates from beef and chicken samples amplified the mecA gene, while 100% of the MRSA isolates amplified the PVL gene. The multidrug resistance profile (resistant to ≥1 antimicrobial agent in ≥3 classes of antimicrobial agents) of the staphylococcal isolates showed that 7 isolates were resistant to methicillin, penicillin, clindamycin, chloramphenicol, trimethoprim-sulfamethoxazole, kanamycin, amoxicillin, cloxacillin, erythromycin, vancomycin, and gentamycin. There was a significant regression effect from the multidrug-resistant profile on the number of isolates (p resistant strains within bacterial populations. The findings of the present study indicate that raw meats in the Benin metropolis were possibly contaminated with pathogenic and multi-drug resistant staphylococci strains and therefore could constitute a risk to public health communities.

A Research of nasal methicillin resistant/sensitive Staphylococcus ...

African Journals Online (AJOL)

A Research of nasal methicillin resistant/sensitive Staphylococcus aureus and pharyngeal beta-haemolytic Streptococcus carriage in midwifery students in Kahramanmaras, Eastern Mediterranean Region of Turkey.

Characterisation of SCCmec elements in methicillin-resistant Staphylococcus aureus isolated from burn patients.

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Namvar, Amirmorteza Ebrahimzadeh; Afshar, Mastaneh; Asghari, Babak; Rastegar Lari, Abdolaziz

2014-06-01

Staphylococcus aureus is an important pathogen, especially in burn units all around the world. Because of the emergence of the β-lactam antibiotic-resistant strains since 1961, concern about the prevalence of methicillin-resistant S. aureus (MRSA) has increased in these units. Resistance to methicillin is mediated by penicillin-binding proteins (PBPs) that have enough affinity for binding to the β-lactam ring, but another kind of protein (PBP2α), which is encoded by the mecA gene, has a lower affinity for binding to these antibiotics. The mecA gene is transferred by SCCmec (staphylococcal cassette chromosome mec) as a mobile genetic element, exclusively found in the Staphylococcus genus. Identification of the frequency of the mecA gene, different SCCmec types and also its incidence may have benefit in surveillance prevention and control of MRSA strains in burn units. In this study, 40 S. aureus isolates were collected from patients hospitalised in Motahari burn center of Tehran, during 2012-2013. Conventional microbiological methods were applied and the confirmed isolates were stored at -20°C for molecular polymerase chain reaction (PCR) tests. The antibiotic resistance pattern was performed by disc diffusion method and finally the different SCCmec types were determined by specific primers. During this research, 40 isolates of S. aureus were collected from burn patients, of which (37.5%) of the specimens belonged to female patients and 62.5% to male patients. The aetiology of the burn was classified as follows: open flame (35%), liquid (32.5%), chemical (5%) and other (27.5%). By a disc diffusion method, no resistance pattern was observed to vancomycin and fosfomycin. Based on a multiplex PCR assay, the five different SCCmec types were detected as: 47.5% type III, 25% type IV, 10% type V, 10% type II and 7.5% type I. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

Removal of total and antibiotic resistant bacteria in advanced wastewater treatment by ozonation in combination with different filtering techniques.

Science.gov (United States)

Lüddeke, Frauke; Heß, Stefanie; Gallert, Claudia; Winter, Josef; Güde, Hans; Löffler, Herbert

2015-02-01

Elimination of bacteria by ozonation in combination with charcoal or slow sand filtration for advanced sewage treatment to improve the quality of treated sewage and to reduce the potential risk for human health of receiving surface waters was investigated in pilot scale at the sewage treatment plant Eriskirch, Baden-Wuerttemberg/Germany. To determine the elimination of sewage bacteria, inflowing and leaving wastewater of different treatment processes was analysed in a culture-based approach for its content of Escherichia coli, enterococci and staphylococci and their resistance against selected antibiotics over a period of 17 month. For enterococci, single species and their antibiotic resistances were identified. In comparison to the established flocculation filtration at Eriskirch, ozonation plus charcoal or sand filtration (pilot-scale) reduced the concentrations of total and antibiotic resistant E. coli, enterococci and staphylococci. However, antibiotic resistant E. coli and staphylococci apparently survived ozone treatment better than antibiotic sensitive strains. Neither vancomycin resistant enterococci nor methicillin resistant Staphylococcus aureus (MRSA) were detected. The decreased percentage of antibiotic resistant enterococci after ozonation may be explained by a different ozone sensitivity of species: Enterococcus faecium and Enterococcus faecalis, which determined the resistance-level, seemed to be more sensitive for ozone than other Enterococcus-species. Overall, ozonation followed by charcoal or sand filtration led to 0.8-1.1 log-units less total and antibiotic resistant E. coli, enterococci and staphylococci, as compared to the respective concentrations in treated sewage by only flocculation filtration. Thus, advanced wastewater treatment by ozonation plus charcoal or sand filtration after common sewage treatment is an effective tool for further elimination of microorganisms from sewage before discharge in surface waters. Copyright © 2014 Elsevier

Prevalence and risk factors for methicillin resistant Staphylococcus ...

African Journals Online (AJOL)

Prevalence and risk factors for methicillin resistant Staphylococcus aureus carriage among emergency department workers and bacterial contamination on touch surfaces in Erciyes University Hospital, Kayseri, Turkey.

Methicillin-Resistant Staphylococcus aureus Infections: A Comprehensive Review and a Plastic Surgeon's Approach to the Occult Sites.

Science.gov (United States)

Hunter, Cedric; Rosenfield, Lorne; Silverstein, Elena; Petrou-Zeniou, Panayiota

2016-08-01

Up to 20 percent of the general population is persistently colonized with Staphylococcus aureus, and 1 to 3 percent of the population is colonized with community-acquired methicillin-resistant S. aureus. Currently, the knowledge of methicillin-resistant Staphylococcus aureus carriage sites other than the nose, and their effect on surgical site infections in cosmetic surgery, is lacking. A comprehensive literature review using the PubMed database to analyze prevalence, anatomical carrier sites, current screening and decontamination protocols and guidelines, and methicillin-resistant S. aureus in cosmetic surgery was performed. The senior author's (L.R.) methicillin-resistant S. aureus infection experience and prevention protocols were also reviewed. Nasal swabs detect only 50.5 percent of methicillin-resistant S. aureus colonization, and broad screening has noted the presence of methicillin-resistant S. aureus in the ear canal and umbilicus. Decolonization protocols within the orthopedic and cardiothoracic surgery literature have reduced rates of methicillin-resistant S. aureus surgical-site infections. There are no decolonization guidelines for plastic surgeons. Since instituting their decolonization protocol, the authors have had no cases of methicillin-resistant S. aureus infection in nearly 1000 cosmetic surgery procedures. There are very limited, if any, Level I or II data regarding methicillin-resistant S. aureus screening and decolonization. As the sequelae of a surgical-site infection can be disastrous, expert opinions recommend that plastic surgeons vigorously address methicillin-resistant S. aureus colonization and infection. The authors have developed and recommend a simple decolonization protocol that includes treatment of the umbilicus, ear canal, and nares to limit surgical-site infection and improve surgical outcomes.

Recovery of vancomycin-resistant gram-positive cocci from children.

OpenAIRE

Green, M; Wadowsky, R M; Barbadora, K

1990-01-01

A cross-sectional survey of vancomycin-resistant gram-positive cocci (VRGPC) in the feces of children was initiated after several bacteremic infections with these organisms occurred at our hospital. A selective medium consisting of colistin-nalidixic acid agar, 5% sheep blood, vancomycin (5 mg/liter), and amphotericin B (8 mg/liter) was developed to isolate VRGPC. A single stool specimen submitted to the clinical microbiology laboratory from each of 48 patients was inoculated onto the medium....

Vancomycin-resistant enterococci with vanA gene in treated municipal wastewater and their association with human hospital strains.

Science.gov (United States)

Oravcova, Veronika; Mihalcin, Matus; Zakova, Jana; Pospisilova, Lucie; Masarikova, Martina; Literak, Ivan

2017-12-31

Vancomycin-resistant enterococci (VRE) are pathogens of increasing medical importance. In Brno, Czech Republic, we collected 37 samples from the effluent of a wastewater treatment plant (WWTP), 21 surface swabs from hospital settings, and 59 fecal samples from hospitalized patients and staff. Moreover, we collected 284 gull cloacal swabs from the colony situated 35km downstream the WWTP. Samples were cultured selectively. Enterococci were identified using MALDI-TOF MS, phenotypically tested for susceptibility to antibiotics, and by PCR for occurrence of resistance and virulence genes. Pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) were used to examine genotypic diversity. VRE carrying the vanA gene were found in 32 (86%, n=37) wastewater samples, from which we obtained 49 isolates: Enterococcus faecium (44) and Enterococcus gallinarum (2), Enterococcus casseliflavus (2), and Enterococcus raffinosus (1). From 33 (69%) of 48 inpatient stool samples, we obtained 39 vanA-carrying VRE, which belonged to E. faecium (33 isolates), Enterococcus faecalis (4), and Enterococcus raffinosus (2). Nearly one-third of the samples from hospital surfaces contained VRE with the vanA gene. VRE were not detected among gulls. Sixty-seven (84%, n=80) E. faecium isolates carried virulence genes hyl and/or esp. Virulence of E. faecalis was encoded by gelE, asa1, and cylA genes. A majority of the E. faecium isolates belonged to the clinically important sequence types ST17 (WWTP: 10 isolates; hospital: 4 isolates), ST18 (9;8), and ST78 (5;0). The remaining isolates belonged to ST555 (2;0), ST262 (1;6), ST273 (3;0), ST275 (1;0), ST549 (2;0), ST19 (0;1), ST323 (3;0), and ST884 (7;17). Clinically important enterococci carrying the vanA gene were almost continually detectable in the effluent of the WWTP, indicating insufficient removal of VRE during wastewater treatment and permanent shedding of these antibiotic resistant pathogens into the environment from this

Lactobacillus rhamnosus GG Outcompetes Enterococcus faecium via Mucus-Binding Pili

NARCIS (Netherlands)

Tytgat, Hanne L.P.; Douillard, François P.; Reunanen, Justus; Rasinkangas, Pia; Hendrickx, Antoni P.A.; Laine, Pia K.; Paulin, Lars; Satokari, Reetta; Vos, de Willem M.

2016-01-01

Vancomycin-resistant enterococci (VRE) have become a major nosocomial threat. Enterococcus faecium is of special concern, as it can easily acquire new antibiotic resistances and is an excellent colonizer of the human intestinal tract. Several clinical studies have explored the potential use of

Reversal of methicillin resistance in Staphylococcus aureus by thioridazine

DEFF Research Database (Denmark)

Klitgaard, Janne K; Skov, Marianne N; Kallipolitis, Birgitte H

2008-01-01

of thioridazine in the presence of a fixed amount of oxacillin. Furthermore, the protein level of PBP2a was reduced when bacteria were treated with the combination of oxacillin and thioridazine. The two drugs also affected the mRNA level of the beta-lactamase gene, blaZ. Conclusions The present study indicates......Objectives Thioridazine has been shown to reverse oxacillin resistance in methicillin-resistant Staphylococcus aureus (MRSA) in vitro. The aim of this study was to investigate whether thioridazine alone or in combination with oxacillin affects the transcription of the methicillin resistance gene...... blotting in the presence of thioridazine and oxacillin. Results We observed an increased susceptibility of MRSA towards oxacillin in the presence of thioridazine compared with bacteria grown with oxacillin or thioridazine alone. Transcription of mecA was reduced with increasing concentrations...

Isolation of vancomycin resistant Enterococcus faecium from food

DEFF Research Database (Denmark)

Wegener, Henrik Caspar; Madsen, Mogens; Nielsen, Niels

1997-01-01

was not detected in 124 samples of pork and 128 samples of beef from retail outlets by the direct plating method. An additional enrichment step in nutrient broth supplemented with vancomycin enhanced the detection rate of VREF by approximately three times compared to the direct plating method when investigating...... the same 160 samples of broilers by the two methods. The implications and public health aspects of VREF in food is discussed....

Antibiotic Resistance Patterns of Enterococci and Occurrence of Vancomycin-Resistant Enterococci in Raw Minced Beef and Pork in Germany

Science.gov (United States)

Klein, Günter; Pack, Alexander; Reuter, Gerhard

1998-01-01

The food chain, especially raw minced meat, is thought to be responsible for an increase in the incidence of vancomycin-resistant enterococci (VRE) in human nosocomial infections. Therefore, 555 samples from 115 batches of minced beef and pork from a European Union-licensed meat-processing plant were screened for the occurrence of VRE. The processed meat came from 45 different slaughterhouses in Germany. Enterococci were isolated directly from Enterococcosel selective agar plates and also from Enterococcosel selective agar plates supplemented with 32 mg of vancomycin per liter. In addition, peptone broth was used in a preenrichment procedure, and samples were subsequently plated onto Enterococcosel agar containing vancomycin. To determine resistance, 209 isolates from 275 samples were tested with the glycopeptides vancomycin, teicoplanin, and avoparcin and 19 other antimicrobial substances by using a broth microdilution test. When the direct method was used, VRE were found in 3 of 555 samples (0.5%) at a concentration of 1.0 log CFU/g of minced meat. When the preenrichment procedure was used, 8% of the samples were VRE positive. Our findings indicate that there is a low incidence of VRE in minced meat in Germany. In addition, the resistance patterns of the VRE isolates obtained were different from the resistance patterns of clinical isolates. A connection between the occurrence of VRE in minced meat and nosocomial infections could not be demonstrated on the basis of our findings. PMID:9572958

Methicillin resistant staphylococci associated with bovine mastitis and their zoonotic importance

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S. Vishnupriya

2014-06-01

Full Text Available Aim: The present study was conducted to determine the zoonotic importance of methicillin resistant staphylococci associated with bovine mastitis and their potential role in transmission to animal handlers. Materials and Methods: A total of 158 milk samples from bovine mastitis cases and 126 nasal swabs from the animal handlers were sampled in and around Pondicherry (Southern India. The Presence of Staphylococcal organism was confirmed by PCR amplification using the genus specific primers and among the isolated Staphylococci; methicillin resistance was identified by genetic amplification of mec A methicillin resistant gene. Then the amplified gene from the bacteria expressing the mecA gene (PBP2a (~2kb fragment was further sequenced using four sets of primer pairs and aligned for determining their genetic relatedness between the sequences. Both phenotypic and genotypic analysis was carried out for the six MRS isolates (three bovine and three human in this study. Results: Out of 158 mastitis milk samples; 96 and 19 bovine isolates were found to be positive for Staphylococcal genus specific PCR and methicillin resistant (mecA gene PCR, respectively. Similarly, Out of 126 human nasal swabs, 64 and 13 human isolates were found to be positive for Staphylococcal genus specific PCR and mec A gene PCR, respectively. Among the 160 staphylococcal isolates (Bovine and Human origin; 51 were identified as coagulase-positive staphylococci (CPS and remaining as coagulase-negative staphylococci (CONS. The results obtained in this study revealed the presence of many species of Staphylococci but the predominant species were Staphylococcus aureus and S. epidermidis. The Sequence analysis of the mec A gene of human isolates obtained in this study had a maximum identity (99% -100% with the bovine isolates. Conclusion: The phenotypic and genotypic analysis carried out for the six MRS (Methicillin Resistant Staphylococci isolates in this study were indistinguishable

Detection of Methicillin Resistant Staphylococcus aureus and Determination of Minimum Inhibitory Concentration of Vancomycin for Staphylococcus aureus Isolated from Pus/Wound Swab Samples of the Patients Attending a Tertiary Care Hospital in Kathmandu, Nepal

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Raghabendra Adhikari

2017-01-01

Full Text Available The present study was conducted to evaluate the performance of cefoxitin disc diffusion method and oxacillin broth microdilution method for detection of methicillin resistant S. aureus (MRSA, taking presence of mecA gene as reference. In addition, inducible clindamycin resistance and beta-lactamase production were studied and minimum inhibitory concentration (MIC of vancomycin for S. aureus isolates was determined. A total of 711 nonrepeated pus/wound swab samples from different anatomic locations were included in the study. The Staphylococcus aureus was identified on the basis of colony morphology, Gram’s stain, and biochemical tests. A total of 110 (15.47% S. aureus isolates were recovered, of which 39 (35.50% isolates were identified as MRSA by cefoxitin disc diffusion method. By oxacillin broth microdilution method, 31.82% of the Staphylococcus aureus isolates were found to be MRSA. However, mecA gene was present in only 29.1% of the isolates. Further, beta-lactamase production was observed in 71.82% of the isolates, while inducible clindamycin resistance was found in 10% of S. aureus isolates. The MIC value of vancomycin for S. aureus ranged from 0.016 μg/mL to 1 μg/mL. On the basis of the absolute sensitivity (100%, both phenotypic methods could be employed for routine diagnosis of MRSA in clinical microbiology laboratory; however cefoxitin disc diffusion could be preferred over MIC method considering time and labour factor.

Correlations between Income inequality and antimicrobial resistance.

Science.gov (United States)

Kirby, Andrew; Herbert, Annie

2013-01-01

The aim of this study is to investigate if correlations exist between income inequality and antimicrobial resistance. This study's hypothesis is that income inequality at the national level is positively correlated with antimicrobial resistance within developed countries. Income inequality data were obtained from the Standardized World Income Inequality Database. Antimicrobial resistance data were obtained from the European antimicrobial Resistance Surveillance Network and outpatient antimicrobial consumption data, measured by Defined daily Doses per 1000 inhabitants per day, from the European Surveillance of antimicrobial Consumption group. Spearman's correlation coefficient (r) defined strengths of correlations of: > 0.8 as strong, > 0.5 as moderate and > 0.2 as weak. Confidence intervals and p values were defined for all r values. Correlations were calculated for the time period 2003-10, for 15 European countries. Income inequality and antimicrobial resistance correlations which were moderate or strong, with 95% confidence intervals > 0, included the following. Enterococcus faecalis resistance to aminopenicillins, vancomycin and high level gentamicin was moderately associated with income inequality (r= ≥0.54 for all three antimicrobials). Escherichia coli resistance to aminoglycosides, aminopenicillins, third generation cephalosporins and fluoroquinolones was moderately-strongly associated with income inequality (r= ≥0.7 for all four antimicrobials). Klebsiella pneumoniae resistance to third generation cephalosporins, aminoglycosides and fluoroquinolones was moderately associated with income inequality (r= ≥0.5 for all three antimicrobials). Staphylococcus aureus methicillin resistance and income inequality were strongly associated (r=0.87). As income inequality increases in European countries so do the rates of antimicrobial resistance for bacteria including E. faecalis, E. coli, K. pneumoniae and S. aureus. Further studies are needed to confirm these

Emergence in Asian Countries of Staphylococcus aureus with Reduced Susceptibility to Vancomycin

Science.gov (United States)

Song, Jae-Hoon; Hiramatsu, Keiichi; Suh, Ji Yoeun; Ko, Kwan Soo; Ito, Teruyo; Kapi, Maria; Kiem, Sungmin; Kim, Yeon-Sook; Oh, Won Sup; Peck, Kyong Ran; Lee, Nam Yong

2004-01-01

To investigate the prevalence of Staphylococcus aureus with reduced susceptibility to vancomycin among methicillin-resistant S. aureus (MRSA) strains in Asian countries, a total of 1,357 clinical isolates of MRSA collected from 12 Asian countries were screened by using brain heart infusion agar plates containing 4 mg of vancomycin per liter. The presence of strains that were heterointermediately resistant to vancomycin (hVISA) was confirmed by population analysis. Of 347 (25.6%) MRSA isolates that grew on the screening agar plates, 58 isolates (4.3%) were hVISA. hVISA strains were found in India, South Korea, Japan, the Philippines, Singapore, Thailand, and Vietnam. However, neither vancomycin-intermediate S. aureus nor vancomycin-resistant S. aureus isolates were found among MRSA isolates from Asian countries in this survey. PMID:15561884

Presence of Methicillin Resistant Staphylococcus aureus (MRSA) in sewage treatment plant.

Science.gov (United States)

Boopathy, Raj

2017-09-01

The presence of antibiotic resistant bacteria and antibiotic resistance genes in rural sewage treatment plants are not well reported in the literature. The aim of the present study was to study the frequency occurrence of Methicillin Resistant Staphylococcus aureus (MRSA) in a rural sewage treatment plant. This study was conducted using raw sewage as well as treated sewage from a small town sewage treatment plant in rural southeast Louisiana of USA. Results showed the presence of MRSA consistently in both raw and treated sewage. The presence of mecA gene responsible for methicillin resistance was confirmed in the raw and treated sewage water samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Isolation and Identification of Methicillin-resistant Staphylococcus ...

African Journals Online (AJOL)

cHyE sHaN

2012-06-21

Jun 21, 2012 ... Accepted 23 March, 2012. Methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial pathogen of increasing risk on community. ... become more prevalent as nosocomial pathogens causing severe infections ... prevention of transmission among hospitalized patients. Unrecognized MRSA carriers ...

Molecular Characterization of Glycopeptide-Resistant Enterococci from Hospitals of the Picardy Region (France

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M. Biendo

2010-01-01

Full Text Available We studied 138 glycopeptide-resistant enterococci (GRE strains, consisting of 131 glycopeptide-resistant Enterococcus faecium (GREfm and 7 glycopeptide-resistant Enterococcus faecalis (GREfs. The GREfm strains were resistant to penicillin, ampicillin, vancomycin, and teicoplanin, while the GREfs strains were only resistant to vancomycin and teicoplanin. The van A gene was the only glycopeptide determinant present in all GRE isolates investigated. Genes coding for Hyl and Hyl+ Esp were detected in 39 (29.8% and 92 (70.2% of the 131 GREfm isolates, respectively. Three of the 7 GREfs were positive for gelE+asa 1 genes, 3 for gel E gene, and 1 for asa 1 gene. The genetic relationship between the 138 GRE was analyzed by pulsed-field gel electrophoresis (PFGE and multilocus sequence typing (MLST. GREfm isolates were clustered in a single genogroup (pulsotype A, and GREfs were clustered in six genogroups (pulsotypes B-G. Among the isolates investigated by MLST, only 18 PCR products were sequenced (12 E. faecium and 6 E. faecalis, and 9 sequence types (STs were identified.

Nanoconjugated vancomycin: new opportunities for the development of anti-VRSA agents

International Nuclear Information System (INIS)

Chakraborty, Subhankari Prasad; Mahapatra, Santanu Kar; Roy, Somenath; Sahu, Sumanta Kumar; Santra, Susmita; Pramanik, Panchanan; Bal, Manjusri

2010-01-01

More than 90% of Staphylococcus strains are resistant to penicillin. In 1961 S. aureus developed resistance to methicillin (MRSA), invalidating almost all antibiotics, including the most potent β-lactams. Vancomycin, a glycopeptide antibiotic, was used for the treatment of MRSA in 1980. Vancomycin inhibits the bio-synthesis of peptidoglycan and the assembly of NAM-NAG-polypeptide into the growing peptidoglycan chain. Vancomycin resistant S. aureus (VRSA) first appeared in the USA in 2002. Folic acid tagged chitosan nanoparticles are used as Trojan horses to deliver vancomycin into bacterial cells. These nanoparticles are biocompatible and biodegradable semisynthetic polymers. These nanosized vehicles enhance the transport of vancomycin across epithelial surfaces and show its efficient drug action, which has been understood from studies of the minimum inhibitory concentration and minimum bactericidal concentration of nanoparticles of a chitosan derivative loaded with vancomycin. Tolerance values distinctly show that vancomycin loaded into nanoconjugate is very effective and has a strong bactericidal effect on VRSA.

Nanoconjugated vancomycin: new opportunities for the development of anti-VRSA agents

Energy Technology Data Exchange (ETDEWEB)

Chakraborty, Subhankari Prasad; Mahapatra, Santanu Kar; Roy, Somenath [Immunology and Microbiology Laboratory, Department of Human Physiology with Community Health, Vidyasagar University, Midnapore-721102 (India); Sahu, Sumanta Kumar; Santra, Susmita; Pramanik, Panchanan [Nanomaterials Laboratory, Department of Chemistry, Indian Institute of Technology, Kharagpur, Pin-721302 (India); Bal, Manjusri, E-mail: panchanan_123@yahoo.com [Department of Human Physiology, Calcutta University, Kolkata (India)

2010-03-12

More than 90% of Staphylococcus strains are resistant to penicillin. In 1961 S. aureus developed resistance to methicillin (MRSA), invalidating almost all antibiotics, including the most potent {beta}-lactams. Vancomycin, a glycopeptide antibiotic, was used for the treatment of MRSA in 1980. Vancomycin inhibits the bio-synthesis of peptidoglycan and the assembly of NAM-NAG-polypeptide into the growing peptidoglycan chain. Vancomycin resistant S. aureus (VRSA) first appeared in the USA in 2002. Folic acid tagged chitosan nanoparticles are used as Trojan horses to deliver vancomycin into bacterial cells. These nanoparticles are biocompatible and biodegradable semisynthetic polymers. These nanosized vehicles enhance the transport of vancomycin across epithelial surfaces and show its efficient drug action, which has been understood from studies of the minimum inhibitory concentration and minimum bactericidal concentration of nanoparticles of a chitosan derivative loaded with vancomycin. Tolerance values distinctly show that vancomycin loaded into nanoconjugate is very effective and has a strong bactericidal effect on VRSA.

The effect of diabetes mellitus on outcomes of patients with nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus: data from a prospective double-blind clinical trial comparing treatment with linezolid versus vancomycin.

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Equils, Ozlem; da Costa, Christopher; Wible, Michele; Lipsky, Benjamin A

2016-09-06

The presence of diabetes mellitus increases the risk of several severe infections, but data on its effect on treatment outcomes in patients with nosocomial pneumonia (NP) caused by methicillin-resistant Staphylococcus aureus (MRSA) are limited. We retrospectively analyzed data from a double-blind, randomized, multi-center, international clinical trial of culture-confirmed MRSA NP that compared treatment with linezolid to vancomycin. Specifically, we evaluated the clinical and microbiologic outcomes of patients with and without diabetes in the modified intent to treat population at end-of-treatment (EOT) and end-of-study (EOS, 7-30 days post-EOT). Among 448 enrolled patients 183 (40.8 %) had diabetes mellitus, 87 (47.5 %) of whom received linezolid and 96 (52.5 %) vancomycin. Baseline demographic and clinical characteristics were similar for the two treatment groups. Clinical success rates at EOS were 57.6 % with linezolid and 39.3 % with vancomycin, while microbiological success rates were 58.9 % with linezolid and 41.1 % with vancomycin. Among diabetic patients, rates of mortality and study drug-related adverse effects were similar between the treatment groups. Overall day 28 mortality rates were higher among diabetic patients compared to non-diabetic patients (23.5 vs 14.7 %, respectively: RD = 8.8 %, 95 % CI [1.4, 16.3]). Among diabetic patients with MRSA NP, treatment with linezolid, compared to vancomycin, was associated with higher clinical and microbiologic success rates, and comparable adverse event rates. NCT00084266 .

State-wide surveillance of antibiotic resistance patterns and spa types of methicillin-resistant Staphylococcus aureus from blood cultures in North Rhine-Westphalia, 2011-2013.

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Cuny, C; Layer, F; Werner, G; Harmsen, D; Daniels-Haardt, I; Jurke, A; Mellmann, A; Witte, W; Köck, R

2015-08-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of bacteraemia. We aimed to obtain a complete picture of severe MRSA infections by characterizing all MRSA isolates from bloodstream infections in the largest German federal state (North Rhine-Westphalia, 18 million inhabitants) using S. aureus protein A (spa) sequence-typing and antimicrobial susceptibility testing. MRSA isolates (n = 1952) were collected prospectively (2011-2013) and spa-typed. Among 181 different spa types, t003 (n = 746 isolates; 38.2%) and t032 (n = 594; 30.4%) were predominant. Analysis of the geographical occurrence of spa clonal complexes (spa-CCs) and spa types revealed divergent distribution between federal state districts for spa-CCs 003 (p resistant to fluoroquinolones, 78% to erythromycin, 70% to clindamycin, 4% to gentamicin, 2% to rifampicin, 0.4% to daptomycin, 0.1% to linezolid and 0% to vancomycin, respectively. Vancomycin MICs of 2 mg/L involved 0.5% of the isolates. In conclusion, the detection of regional molecular clusters added valuable information for epidemiological case tracing and allowed conclusions to be reached on the importance of newly emerging MRSA reservoirs, such as livestock (spa-CC011), for MRSA bacteraemia in some parts of the federal state. Susceptibility testing revealed broad resistance to substances used for oral treatment, but demonstrated that those antibiotics that are mostly applied for treatment of MRSA bacteraemia and important combination partners were highly susceptible. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Experiences of nursing staff caring for patients with methicillin-resistant Staphylococcus aureus.

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Andersson, H; Andreassen Gleissman, S; Lindholm, C; Fossum, B

2016-06-01

Methicillin-resistant Staphylococcus aureus is a resistant variant of S. aureus and can cause pneumonia, septicaemia and, in some cases, death. Caring for patients with antibiotic resistant bacteria is a challenge for healthcare personnel. There is a risk of spreading the bacteria among patients and of healthcare personnel being infected themselves. To describe nursing staffs' experiences of caring for patients with methicillin-resistant S. aureus in Sweden. A descriptive qualitative approach was used and 15 nurses from different hospitals and care units, including emergency and geriatric wards and nursing homes in Stockholm, were interviewed. All nurses had been involved in the care of patients with methicillin-resistant S. aureus, but not on a regular basis. The interviews were analysed using qualitative content analysis. Three themes emerged from the data: feeling ignorant, afraid and insecure, feeling competent and secure and feeling stressed and overworked. The more knowledge the nurses acquired about methicillin-resistant S. aureus, the more positive was their attitude to caring for these patients. Caring for patients with methicillin-resistant S. aureus without adequate knowledge of how to protect oneself and other patients against transmission may provoke anxiety among personnel. Guidelines, memos and adequate information at the right time are of central importance. Healthcare personnel must feel safe in their role as caregivers. All patients have the right to have the same quality of care regardless of the diagnosis and a lack of knowledge influences the level of care given. This study demonstrates the importance of education when caring for patients with infectious diseases. Hopefully, knowledge gained from our study can provide guidance for future health care when new diseases and infections occur. © 2016 International Council of Nurses.

General Disinfection in Medical and Dental Hospitals, Selection of Disinfectant Type and Problems Encountered

OpenAIRE

Akça, Gülin

2015-01-01

Hospitals are the places where, either the patients or other health workers can encounter with dangerous problem of several bacterial, fungal, viral, parasitic infectious agents, especially the emerging and life threatening ones such as, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin resistant Enterococcus faecalis (VRE), Stenotrophomonas sp., and multi drug resistant Acinetobacter sp., Pseudomonas sp.. The reasons of these resistant microorganisms that can threaten the life o...

Gas Plasma Pre-treatment Increases Antibiotic Sensitivity and Persister Eradication in Methicillin-Resistant Staphylococcus aureus

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Guo, Li; Xu, Ruobing; Zhao, Yiming; Liu, Dingxin; Liu, Zhijie; Wang, Xiaohua; Chen, Hailan; Kong, Michael G.

2018-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of serious nosocomial infections, and recurrent MRSA infections primarily result from the survival of persister cells after antibiotic treatment. Gas plasma, a novel source of ROS (reactive oxygen species) and RNS (reactive nitrogen species) generation, not only inactivates pathogenic microbes but also restore the sensitivity of MRSA to antibiotics. This study further found that sublethal treatment of MRSA with both plasma and plasma-activated saline increased the antibiotic sensitivity and promoted the eradication of persister cells by tetracycline, gentamycin, clindamycin, chloramphenicol, ciprofloxacin, rifampicin, and vancomycin. The short-lived ROS and RNS generated by plasma played a primary role in the process and induced the increase of many species of ROS and RNS in MRSA cells. Thus, our data indicated that the plasma treatment could promote the effects of many different classes of antibiotics and act as an antibiotic sensitizer for the treatment of antibiotic-resistant bacteria involved in infectious diseases. PMID:29628915

Phage therapy against Enterococcus faecalis in dental root canals

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Leron Khalifa

2016-09-01

Full Text Available Antibiotic resistance is an ever-growing problem faced by all major sectors of health care, including dentistry. Recurrent infections related to multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus, carbapenem-resistant Enterobacteriaceae, and vancomycin-resistant enterococci (VRE in hospitals are untreatable and question the effectiveness of notable drugs. Two major reasons for these recurrent infections are acquired antibiotic resistance genes and biofilm formation. None of the traditionally known effective techniques have been able to efficiently resolve these issues. Hence, development of a highly effective antibacterial practice has become inevitable. One example of a hard-to-eradicate pathogen in dentistry is Enterococcus faecalis, which is one of the most common threats observed in recurrent root canal treatment failures, of which the most problematic to treat are its biofilm-forming VRE strains. An effective response against such infections could be the use of bacteriophages (phages. Phage therapy was found to be highly effective against biofilm and multidrug-resistant bacteria and has other advantages like ease of isolation and possibilities for genetic manipulations. The potential of phage therapy in dentistry, in particular against E. faecalis biofilms in root canals, is almost unexplored. Here we review the efforts to develop phage therapy against biofilms. We also focus on the phages isolated against E. faecalis and discuss the possibility of using phages against E. faecalis biofilm in root canals.

vanI: a novel d-Ala-d-Lac vancomycin resistance gene cluster found in Desulfitobacterium hafniense

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Kruse, T.; Levisson, M.; Vos, de W.M.; Smidt, H.

2014-01-01

The glycopeptide vancomycin was until recently considered a drug of last resort against Gram-positive bacteria. Increasing numbers of bacteria, however, are found to carry genes that confer resistance to this antibiotic. So far, 10 different vancomycin resistance clusters have been described. A

Antimicrobial resistance and virulence profile of enterococci isolated from poultry and cattle sources in Nigeria.

Science.gov (United States)

Ngbede, Emmanuel Ochefije; Raji, Mashood Abiola; Kwanashie, Clara Nna; Kwaga, Jacob Kwada Paghi

2017-03-01

This study investigated the occurrence, antimicrobial resistance and virulence of Enterococcus from poultry and cattle farms. Three hundred and ninety samples: cloacal/rectal swabs (n = 260) and manure (n = 130] were processed for recovery of Enterococcus species. Standard bacteriological methods were used to isolate, identify and characterize Enterococcus species for antimicrobial susceptibility and expression of virulence traits. Detection of antibiotic resistance and virulence genes was carried out by polymerase chain reaction. Enterococcus was recovered from 167 (42.8%) of the 390 samples tested with a predominance of Enterococcus faecium (27.7%). Other species detected were Enterococcus gallinarum, Enterococcus faecalis, Enterococcus hirae, Enterococcus raffinosus, Enterococcus avium, Enterococcus casseliflavus, Enterococcus mundtii and Enterococcus durans. All the isolates tested were susceptible to vancomycin, but resistance to tetracycline, erythromycin, ampicillin and gentamicin was also observed among 61.0, 61.0, 45.1 and 32.7% of the isolates, respectively. Sixty (53.1%) of the isolates were multidrug resistant presenting as 24 different resistance patterns with resistance to gentamicin-erythromycin-streptomycin-tetracycline (CN-ERY-STR-TET) being the most common (n = 11) pattern. In addition to expression of virulence traits (haemolysin, gelatinase, biofilm production), antibiotic resistance (tetK, tetL, tetM, tetO and ermB) and virulence (asa1, gelE, cylA) genes were detected among the isolates. Also, in vitro transfer of resistance determinants was observed among 75% of the isolates tested. Our data revealed poultry, cattle and manure in this area are hosts to varying Enterococcus species harbouring virulence and resistance determinants that can be transferred to other organisms and also are important for causing nosocomial infection.

Isolation and Host Range of Bacteriophage with Lytic Activity against Methicillin-Resistant Staphylococcus aureus and Potential Use as a Fomite Decontaminant.

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Kyle C Jensen

Full Text Available Staphylococcus aureus (SA is a commensal bacterium and opportunistic pathogen commonly associated with humans and is capable of causing serious disease and death including sepsis, pneumonia, and meningitis. Methicillin-resistant SA (MRSA isolates are typically resistant to many available antibiotics with the common exception of vancomycin. The presence of vancomycin resistance in some SA isolates combined with the current heavy use of vancomycin to treat MRSA infections indicates that MRSA may achieve broad resistance to vancomycin in the near future. New MRSA treatments are clearly needed. Bacteriophages (phages are viruses that infect bacteria, commonly resulting in death of the host bacterial cell. Phage therapy entails the use of phage to treat or prevent bacterial infections. In this study, 12 phages were isolated that can replicate in human SA and/or MRSA isolates as a potential way to control these infections. 5 phage were discovered through mitomycin C induction of prophage and 7 others as extracellular viruses. Primary SA strains were also isolated from environmental sources to be used as tools for phage discovery and isolation as well as to examine the target cell host range of the phage isolates by spot testing. Primary isolates were tested for susceptibility to oxacillin in order to determine which were MRSA. Experiments were performed to assess the host range and killing potential of newly discovered phage, and significant reductions in bacterial load were detected. We explored the utility of some phage to decontaminate fomites (glass and cloth and found a significant reduction in colony forming units of MRSA following phage treatment, including tests of a phage cocktail against a cocktail of MRSA isolates. Our findings suggest that phage treatment can be used as an effective tool to decontaminate human MRSA from both hard surfaces and fabrics.

Graphene oxide-silver nanocomposite as a promising biocidal agent against methicillin-resistant Staphylococcus aureus.

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de Moraes, Ana Carolina Mazarin; Lima, Bruna Araujo; de Faria, Andreia Fonseca; Brocchi, Marcelo; Alves, Oswaldo Luiz

2015-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) has been responsible for serious hospital infections worldwide. Nanomaterials are an alternative to conventional antibiotic compounds, because bacteria are unlikely to develop microbial resistance against nanomaterials. In the past decade, graphene oxide (GO) has emerged as a material that is often used to support and stabilize silver nanoparticles (AgNPs) for the preparation of novel antibacterial nanocomposites. In this work, we report the synthesis of the graphene-oxide silver nanocomposite (GO-Ag) and its antibacterial activity against relevant microorganisms in medicine. GO-Ag nanocomposite was synthesized through the reduction of silver ions (Ag(+)) by sodium citrate in an aqueous GO dispersion, and was extensively characterized using ultraviolet-visible absorption spectroscopy, X-ray diffraction, thermogravimetric analysis, X-ray photoelectron spectroscopy, and transmission electron microscopy. The antibacterial activity was evaluated by microdilution assays and time-kill experiments. The morphology of bacterial cells treated with GO-Ag was investigated via transmission electron microscopy. AgNPs were well distributed throughout GO sheets, with an average size of 9.4±2.8 nm. The GO-Ag nanocomposite exhibited an excellent antibacterial activity against methicillin-resistant S. aureus, Acinetobacter baumannii, Enterococcus faecalis, and Escherichia coli. All (100%) MRSA cells were inactivated after 4 hours of exposure to GO-Ag sheets. In addition, no toxicity was found for either pristine GO or bare AgNPs within the tested concentration range. Transmission electronic microscopy images offered insights into how GO-Ag nanosheets interacted with bacterial cells. Our results indicate that the GO-Ag nanocomposite is a promising antibacterial agent against common nosocomial bacteria, particularly antibiotic-resistant MRSA. Morphological injuries on MRSA cells revealed a likely loss of viability as a result of the

Cationic compounds with activity against multidrug-resistant bacteria: interest of a new compound compared with two older antiseptics, hexamidine and chlorhexidine.

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Grare, M; Dibama, H Massimba; Lafosse, S; Ribon, A; Mourer, M; Regnouf-de-Vains, J-B; Finance, C; Duval, R E

2010-05-01

Use of antiseptics and disinfectants is essential in infection control practices in hospital and other healthcare settings. In this study, the in vitro activity of a new promising compound, para-guanidinoethylcalix[4]arene (Cx1), has been evaluated in comparison with hexamidine (HX) and chlorhexidine (CHX), two older cationic antiseptics. The MICs for 69 clinical isolates comprising methicillin-resistant Staphylococcus aureus, methicillin-sensitive S. aureus, coagulase-negative staphylococci (CoNS) (with or without mecA), vancomycin-resistant enterococci, Enterobacteriaceae producing various beta-lactamases and non-fermenting bacilli (Pseudomonas aeruginosa, Acinetobacter baumanii, Stenotrophomonas maltophilia) were determined. Cx1 showed similar activity against S. aureus, CoNS and Enterococcus spp., irrespective of the presence of mecA or van genes, or associated resistance genes, with very good activity against CoNS (MIC compound against all strains, with broad-spectrum and conserved activity against multidrug-resistant strains. HX showed a lower activity, essentially against Gram-positive strains. Consequently, the differences observed with respect to Cx1 suggest that they are certainly not the consequence of antibiotic resistance phenotypes, but rather the result of membrane composition modifications (e.g. of lipopolysaccharide), or of the presence of (activated) efflux-pumps. These results raise the possibility that Cx1 may be a potent new antibacterial agent of somewhat lower activity but significantly lower toxicity than CHX.

Methicillin-resistant Staphylococcus aureus prevention strategies in the ICU: a clinical decision analysis*.

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Ziakas, Panayiotis D; Zacharioudakis, Ioannis M; Zervou, Fainareti N; Mylonakis, Eleftherios

2015-02-01

ICUs are a major reservoir of methicillin-resistant Staphylococcus aureus. Our aim was to estimate costs and effectiveness of methicillin-resistant Staphylococcus aureus prevention policies. We evaluated three up-to-date methicillin-resistant Staphylococcus aureus prevention policies, namely, 1) nasal screening and contact precautions of methicillin-resistant Staphylococcus aureus-positive patients; 2) nasal screening, contact precautions, and decolonization (targeted decolonization) of methicillin-resistant Staphylococcus aureus carriers; and 3) universal decolonization without screening. We implemented a decision-analytic model with deterministic and probabilistic analyses. Methicillin-resistant Staphylococcus aureus infections averted, quality-adjusted life years gained, and incremental cost-effectiveness ratios were calculated. Cost-effectiveness planes and acceptability curves were plotted for various willingness-to-pay thresholds to address uncertainty. At base-case scenario, universal decolonization was the dominant strategy; it averted 1.31% and 1.59% of methicillin-resistant Staphylococcus aureus infections over targeted decolonization and screening and contact precautions, respectively, and saved $16,203/quality-adjusted life year over targeted decolonization and 14,562/quality-adjusted life year over screening and contact precautions. Results were robust in sensitivity analysis for a wide range of input variables. In probabilistic analysis, universal decolonization increased quality-adjusted life years by 1.06% (95% CI, 1.02-1.09) over targeted decolonization and by 1.29% (95% CI, 1.24-1.33) over screening and contact precautions; universal decolonization resulted in average savings of $172 (95% CI, $168-$175) and $189 (95% CI, $185-$193) over targeted decolonization and screening and contact precautions, respectively. With willingness-to-pay threshold per quality-adjusted life year gained ranging from $0 to $50,000, universal decolonization was dominant

Prevalence and antimicrobial susceptibility pattern of methicillin resistant Staphylococcus aureus isolated from clinical samples at Yekatit 12 Hospital Medical College, Addis Ababa, Ethiopia.

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Dilnessa, Tebelay; Bitew, Adane

2016-08-09

Staphylococcus aureus particularly MRSA strains are one of the major causes of community and hospital acquired bacterial infections. They are also becoming increasingly multi-drug resistant and have recently developed resistance to vancomycin, which has been used successfully to treat MRSA for many years. In-vitro determination of drug resistance patterns of S. aureus is critical for the selection of effective drugs for the treatment of staphylococci infections. The main aim of this study was to determine the prevalence of methicillin resistant S. aureus strains from different clinical specimens from patients referred for routine culture and sensitivity testing. A cross sectional study was conducted among 1360 participants at Yekatit 12 Hospital Medical College in Ethiopia from September 2013 to April 2014. Clinical samples from various anatomical sites of study participants were cultured on blood agar and mannitol salt agar and identified to be S. aureus by using catalase, coagulase and DNAse tests. S. aureus isolates then were screened for MRSA using 30 μg cefoxitin disc and other 11 antimicrobial drugs by disc diffusion procedure, and agar dilution and E tests for vancomycin. All S. aureus isolates examined for beta-lactamase production by employing nitrocefin. Data were analyzed using SPSS version 20 software and logistic regressions were applied to assess any association between dependent and independent variables. Of 1360 clinical specimens analyzed S. aureus was recovered from (194, 14.3 %). Rate of isolation of S. aureus with regard to clinical specimens was the highest in pus (118, 55.4 %).No S. aureus was isolated from CSF and urethral discharge. Out of 194 S. aureus isolates, (34, 17.5 %) were found out to be MRSA and the remaining (160, 82.5 %) were MSSA. Ninety eight (50.5 %) S. aureus were multi drug resistant and the highest isolates were resistant to penicillin (187, 96.4 %) and least resistant for clindamycin (23, 11.9 %) and vancomycin

Methicillin-resistant Staphylococcus aureus prevalence: Current susceptibility patterns in Trinidad

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Land Michael

2006-05-01

Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA has become one of the most widespread causes of nosocomial infections worldwide. Recently, reports have emerged that S. aureus strains recovered from community-acquired infections are also methicillin-resistant. This study was undertaken to analyze the prevalence of methicillin resistance among isolates at a regional hospital in Trinidad, and document the current resistance profile of MRSA and methicillin-sensitive Staphylococcus aureus (MSSA to the commonly used anti-staphylococcal agents. Methods Over a 6-year period we analyzed 2430 isolates of S. aureus strains recovered from various clinical sources, from hospital and community practices. Antimicrobial susceptibility testing was done according to guideline recommendations of the National Committee for Clinical Laboratory Standards. Results The prevalence of MRSA from surgical/burn wounds, urine and pus/abscess were 60.1%, 15.5% and 6.6%, respectively. The major sources of MSSA were surgical/burn wounds, pus/abscess and upper respiratory tract specimens with rates of 32.9%, 17.1% and 14.3%, respectively. The greatest prevalence of resistance of MRSA was seen for erythromycin (86.7%, and clindamycin (75.3%. Resistance rates among MSSA were highest for ampicillin (70%. Resistance rates for tetracycline were similar among both MRSA (78.7% and MSSA (73.5%. The MRSA recovery rates from nosocomial sources (20.8% was significantly higher than that of previous years (12.5% (p Conclusion The prevalence of MRSA in the hospital increased from 12.5% in 1999 to 20.8% in 2004. Most isolates were associated with infected surgical/burn wounds which may have become infected via the hands of HCPs during dressing exercises. Infection control measures aimed at the proper hand hygiene procedures may interrupt the spread of MRSA. HCPs may also be carriers of MRSA in their anterior nares. Surveillance cultures of both patients and HCPs may help

Identification of Variable Traits among the Methicillin Resistant and Sensitive Coagulase Negative Staphylococci in Milk Samples from Mastitic Cows in India

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Sudipta Mahato

2017-07-01

Full Text Available Methicillin resistant Staphylococcus aureus causing bovine mastitis has been very well investigated worldwide. However, there are only limited reports on the characterization of methicillin resistant and sensitive coagulase negative staphylococci (CoNS across the globe. Hence, in the present study, we aim to determine the phenotypic traits based on antimicrobial susceptibility profile and genotypic characterization by verifying the presence of resistance determinants, virulence and toxin genes present in the CoNS causing clinical mastitis. We obtained 62 CoNS isolates from 167 mastitic milk samples collected from three different states of India. The 62 isolates comprises of 10 different CoNS species S. sciuri, S. haemolyticus, S. chromogenes, S. saprophyticus, S. xylosus, S. simulans, S. agnetis, S. epidermidis, S. gallinarum, and S. cohinii. Susceptibility screening against 11 antibiotics determined 45.16% isolates as multidrug resistant (resistant to more than two class of antibiotic, 46.74% resistant (one or two antibiotic class and 8.06% isolates were pan-sensitive (sensitive to all drugs. High resistance was observed against oxacillin and cefoxitin, whereas all isolates were susceptible toward vancomycin and linezolid. Fifty three isolates were methicillin resistant and 9 isolates were sensitive as determined by oxacillin susceptibility assay. The methicillin resistance gene, mecA was found in 95.16% isolates and staphylococcal cassette chromosome mec (SCCmec typing predominantly revealed Type III (n = 34 and Type V (n = 18. Interestingly, 11.9% of mecA positive isolates were oxacillin susceptible and referred as oxacillin susceptible mecA positive staphylococci (OS-MRS. Additionally, genes encoding for enterotoxin, (sea, seb, seh, see toxic shock syndrome (tsst, exfoliatin (eta, etb, etd and virulence (pvl, Y-hlg were also screened. Of all the genes examined, 67.74% of isolate were positive for the Y-hlg gene, followed by the sea gene in

Prevalence of the antibiotic resistance genes in coagulase-positive- and negative-Staphylococcus in chicken meat retailed to consumers

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Kamelia Mahmoud Osman

2016-11-01

Full Text Available The use of antibiotics in farm management (growing crops and raising animals has become a major area of concern. Its implications is the consequent emergence of antibiotic resistant bacteria (ARB and accordingly their access into the human food chain with passage of antibiotic resistance genes (ARG to the normal human intestinal microbiota and hence to other pathogenic bacteria causative human disease. Therefore, we pursued in this study to unravel the frequency and the quinolone resistance determining region, mecA and cfr genes of methicillin-susceptible Staphylococcus aureus (MSSA, methicillin-resistant S. aureus (MRSA, methicillin-resistant coagulase-negative staphylococci (MRCNS and methicillin-susceptible coagulase-negative staphylococci (MSCNS isolated from the retail trade of ready-to-eat raw chicken meat samples collected during one year and sold across the Great Cairo area. The 50 Staphylococcus isolated from retail raw chicken meat were analyzed for their antibiotic resistance phenotypic profile on 12 antibiotics (penicillin, oxacillin, methicillin, ampicillin-sulbactam, erythromycin, tetracycline, clindamycin, gentamicin, ciprofloxacin, chloramphenicol, sulfamethoxazole-trimethoprim and vancomycin and their endorsement of the quinolone resistance determining region, mecA and cfr genes. The isolation results revealed 50 isolates, CPS (14 and CNS (36, representing ten species (S. aureus, S. hyicus, S. epidermedius, S. lugdunensis, S. haemolyticus, S. hominus, S. schleiferi, S. cohnii, S. intermedius and S. lentus. Twenty seven isolates were methicillin-resistant. Out of the characterized 50 staphylococcal isolates, three were MRSA but only 2/3 carried the mecA gene. The ARG that bestows resistance to quinolones, β-lactams, macrolides, lincosamides and streptogramin B (MLS(B in MRSA and MR-CNS were perceived. According to the available literature, the present investigation was a unique endeavor into the identification of the quinolone-resistance

Prevalence of the Antibiotic Resistance Genes in Coagulase-Positive-and Negative-Staphylococcus in Chicken Meat Retailed to Consumers.

Science.gov (United States)

Osman, Kamelia; Badr, Jihan; Al-Maary, Khalid S; Moussa, Ihab M I; Hessain, Ashgan M; Girah, Zeinab M S Amin; Abo-Shama, Usama H; Orabi, Ahmed; Saad, Aalaa

2016-01-01

The use of antibiotics in farm management (growing crops and raising animals) has become a major area of concern. Its implications is the consequent emergence of antibiotic resistant bacteria (ARB) and accordingly their access into the human food chain with passage of antibiotic resistance genes (ARG) to the normal human intestinal microbiota and hence to other pathogenic bacteria causative human disease. Therefore, we pursued in this study to unravel the frequency and the quinolone resistance determining region, mec A and cfr genes of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), methicillin-resistant coagulase-negative staphylococci (MRCNS) and methicillin-susceptible coagulase-negative staphylococci (MSCNS) isolated from the retail trade of ready-to-eat raw chicken meat samples collected during 1 year and sold across the Great Cairo area. The 50 Staphylococcus isolated from retail raw chicken meat were analyzed for their antibiotic resistance phenotypic profile on 12 antibiotics (penicillin, oxacillin, methicillin, ampicillin-sulbactam, erythromycin, tetracycline, clindamycin, gentamicin, ciprofloxacin, chloramphenicol, sulfamethoxazole-trimethoprim, and vancomycin) and their endorsement of the quinolone resistance determining region, mec A and cfr genes. The isolation results revealed 50 isolates, CPS (14) and CNS (36), representing ten species ( S. aureus, S. hyicus, S. epidermedius, S. lugdunensis, S. haemolyticus, S. hominus, S. schleiferi, S. cohnii, S. intermedius , and S. lentus ). Twenty seven isolates were methicillin-resistant. Out of the characterized 50 staphylococcal isolates, three were MRSA but only 2/3 carried the mec A gene. The ARG that bestows resistance to quinolones, β-lactams, macrolides, lincosamides, and streptogramin B [MLS( B )] in MRSA and MR-CNS were perceived. According to the available literature, the present investigation was a unique endeavor into the identification of the quinolone-resistance

Prevalence and Pattern of Methicillin Resistant Staphylococcus ...

African Journals Online (AJOL)

This trend is on the increase consequently there is prolong hospital stay, increased hospital bills, and increased morbidity and mortality. The widespread use of antimicrobial agents such as the â- lactam antibiotics has contributed to the emergence of Methicillin Resistant Staphylococcus aureus(MRSA); which has become ...

VanA and VanB Positive Vancomycin-resistant Staphylococcus aureus Among Clinical Isolates in Shiraz, South of Iran

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Sareh Saadat

2014-09-01

Full Text Available Objective: The purpose of this study was to determine the prevalence of vancomycin-resistant Staphylococcus aureus isolated from clinical samples in Shiraz hospitals. Methods: From March to December 2012, 100 S. aureus isolates (mainly from wound and blood were collected from three hospitals in Shiraz, south of Iran. After identification of Staphylococcus aureus by biochemical, microbiological and molecular methods, antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion test for 13 different antibiotics. Vancomycin-resistant Staphylococcus aureus isolates were determined by vancomycin agar screening test and PCR for vancomycin resistant genes (vanA and vanB. Results: The lowest and highest resistance was seen for quinupristin-dalfopristin (n=1 and ampicillin (n=95, respectively. Vancomycin agar screening test showed that 37 isolates can grow on these media. Further study by PCR also detected vanA and/or vanB genes in all of these strains. Also, 19 isolates showed either vanA or vanB but were susceptible according to vancomycin agar screening test. In total, vanA and vanB resistant genes were detected in 34% and 37% of clinical isolates, respectively. Conclusion: The results showed that the frequency of vancomycin resistance genes (vanA, vanB is very high in Staphylococcus aureus strains isolated from patients in south of Iran. Thus, urgent interventions are needed to keep the emergence and transmission of these isolates to a minimum.

Enterocin A mutants identified by saturation mutagenesis enhance potency towards vancomycin-resistant Enterococci.

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McClintock, Maria K; Kaznessis, Yiannis N; Hackel, Benjamin J

2016-02-01

Vancomycin-resistant Enterococci infections are a significant clinical problem. One proposed solution is to use probiotics, such as lactic acid bacteria, to produce antimicrobial peptides at the site of infection. Enterocin A, a class 2a bacteriocin, exhibits inhibitory activity against E. faecium and E. faecalis, which account for 86% of vancomycin-resistant Enterococci infections. In this study, we aimed to engineer enterocin A mutants with enhanced potency within a lactic acid bacterial production system. Peptide mutants resulting from saturation mutagenesis at sites A24 and T27 were efficiently screened in a 96-well plate assay for inhibition of pathogen growth. Several mutants exhibit increased potency relative to wild-type enterocin A in both liquid- and solid-medium growth assays. In particular, A24P and T27G exhibit enhanced inhibition of multiple strains of E. faecium and E. faecalis, including clinically isolated vancomycin-resistant strains. A24P and T27G enhance killing of E. faecium 8 by 13 ± 3- and 18 ± 4-fold, respectively. The engineered enterocin A/lactic acid bacteria systems offer significant potential to combat antibiotic-resistant infections. © 2015 Wiley Periodicals, Inc.

Co-infection of methicillin-resistant Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus and extended spectrum β-lactamase producing Escherichia coli in bovine mastitis--three cases reported from India.

Science.gov (United States)

Bandyopadhyay, Samiran; Samanta, Indranil; Bhattacharyya, Debaraj; Nanda, Pramod Kumar; Kar, Debasish; Chowdhury, Jayanta; Dandapat, Premanshu; Das, Arun Kumar; Batul, Nayan; Mondal, Bimalendu; Dutta, Tapan Kumar; Das, Gunjan; Das, Bikash Chandra; Naskar, Syamal; Bandyopadhyay, Uttam Kumar; Das, Suresh Chandra; Bandyopadhyay, Subhasish

2015-03-01

Emergence of antimicrobial resistance among bovine mastitis pathogens is the major cause of frequent therapeutic failure and a cause of concern for veterinary practitioners. This study describes intra-mammary infection of methicillin-resistant Staphylococcus epidermidis (MRSE), methicillin-resistant Staphylococcus aureus (MRSA) and extended spectrum β-lactamase (ESBL) producing Escherichia coli in two Holstein Friesian crossbred cows with subclinical mastitis and one non-descript cow with clinical mastitis in two different districts of West Bengal, India. In total, three MRSE, one MRSA and three ESBL producing E. coli were isolated from these cases. Both the crossbreds were detected with MRSE (HFSE1 and HFSE2) and ESBL producing E. coli (HFEC1 and HFEC2), whereas, simultaneous infection of three pathogens viz. MRSA (NDSA1), MRSE (NDSE1) and ESBL producing E. coli (NDEC1) was found in the non-descript cow. The methicillin-resistant isolates possessed mecA gene and exhibited resistance to various antibiotics such as amikacin, tetracycline and glycopeptides. The ESBL producers were positive for blaCTX-M and blaTEM genes; in addition, HFEC1 and HFEC2 were positive for blaSHV and possessed the genes for class I integron (int1), sulphonamide resistance (sul1), quinolone resistance (qnrS) and other virulence factors (papC, iucD and ESTA1). All the ESBL producers exhibited resistance to a variety of antibiotics tested including third- and fourth-generation cephalosporins and were also intermediately resistant to carbapenems. This is the first ever report on simultaneous occurrence of MRSE, MRSA and ESBL producing E. coli in bovine mastitis indicating a major concern for dairy industry and public health as well.

Isolation of methicillin-resistant Staphylococcus pseudintermedius from breeding dogs.

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Rota, Ada; Milani, Chiara; Drigo, Ilenia; Drigo, Michele; Corrò, Michela

2011-01-01

The overuse of antimicrobials can select resistant bacteria strains; staphylococci have the ability to become resistant to all beta-lactam antimicrobials and are a significant concern in human medicine and a growing issue for veterinary medicine. Because antimicrobials are sometimes incorrectly used in breeding kennels, the objective of the work was to assess the occurrence of methicillin-resistant coagulase-positive staphylococci in breeding dogs. The research was carried out in 13 kennels that were allotted to three categories according to the intensity of antimicrobial use. Vaginal and milk swabs were taken from 87 healthy bitches around parturition and also from multiple organs of 27 of their pups that died within the first 2 weeks. Standard bacteriological examinations were carried out and coagulase-positive staphylococci were identified. All the coagulase-positive staphylococci resulted to be Staphylococcus pseudintermedius. Susceptibility to oxacillin and the presence of the mecA gene were tested. Nine out of 89 strains (six isolated from the bitches' milk and three from dead puppies, all belonging to kennels characterized by an excessive use of antimicrobials) were multidrug-resistant, methicillin-resistant and mecA positive. Our results confirm that excessive use of antimicrobials entails the risk of selecting resistant staphylococci strains. Our data also indicate that the bacterial flora of healthy dogs belonging to specific populations may act as a reservoir of resistance genes. Copyright © 2011 Elsevier Inc. All rights reserved.

Prevalence of methicillin-resistant Staphylococcus aureus (MRSA ...

African Journals Online (AJOL)

One of each duplicate swab sample was inoculated directly onto chocolate agar, incubated for 24 hours at 37oc while the other swab was used to make a smear for Gram staining. All isolates were identified using standard microbiological methods. Staphylococcus aureus isolates were screened for methicillin resistance ...

Nutritional control of antibiotic production by Streptomyces platensis MA7327: importance of L-aspartic acid

OpenAIRE

Falzone, Maria; Crespo, Emmanuel; Jones, Klarissa; Khan, Gulaba; Korn, Victoria L; Patel, Amreen; Patel, Mira; Patel, Krishnaben; Perkins, Carrie; Siddiqui, Sana; Stenger, Drew; Yu, Eileen; Gelber, Michael; Scheffler, Robert; Nayda, Vasyl

2017-01-01

Streptomyces platensis MA7327 is a bacterium producing interesting antibiotics, which act by the novel mechanism of inhibiting fatty acid biosynthesis. The antibiotics produced by this actinomycete are platensimycin and platencin plus some minor related antibiotics. Platensimycin and platencin have activity against antibiotic-resistant bacteria such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus; they also lack toxicity in animal models. Platensimycin als...

Postoperative infection of an abdominal mesh due to methicillin resistant Staphylococcus Aureus - A case report

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Ashok R

2004-01-01

Full Text Available Methicillin resistant Stephylococcus aureus (MRSA infection has now become a major problem in hospitals. We present a case of postoperative infection MRSA where the primary source of the infection was found to be an abdominal mesh that was used to reinforce the abdominal wall. After one year of surgery, the patient developed wound dehiscence and discharge. MRSA was isolated from the wound, mesh, external nares, throat and axilla. Initially she was started on clindamycin and discharged from the hospital. After 5 months, patient came back to the hospital with infection at the same site. The patient was then treated with vancomycin and MRSA clearance. She responded to the treatment with complete healing of the wound and clearance of MRSA.

Vancomycin, linezolid and daptomycin susceptibility pattern among clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA from Sub- Himalyan Center

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Afzal Husain

2018-01-01

CONCLUSION: MIC creep was observed with vancomycin. Although linezolid MIC was within the susceptible zone, more than 40% strains showing MIC 3 μg/ml may herald the future development of either resistant or heteroresistant. Daptomycin showed good sensitivity against MRSA isolates. Therefore, it could be considered as an alternative agent for the treatment of infections caused by MRSA. However, it should be reserved where this class has a clear therapeutic advantage over other anti-MRSA drugs.

Mechanisms of methicillin resistance in Staphylococcus aureus and methods for laboratory detection.

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Jorgensen, J H

1991-01-01

Three distinctly different mechanisms of methicillin resistance have been described in Staphylococcus aureus. The best-documented and probably most important mechanism is production of a unique, low affinity penicillin-binding protein, PBP 2a. Strains possessing PBP 2a are resistant to methicillin, oxacillin, and probably all other currently available beta-lactam antibiotics. Two additional mechanisms of reduced susceptibility to methicillin have been described. Borderline resistance (BORSA) to the semi-synthetic penicillins has been attributed to the hyperproduction of normal staphylococcal beta-lactamase. A third mechanism has recently been advanced that describes an intermediate level of resistance to methicillin due to production of modified, normal PBPs with reduced affinity for beta-lactams (MODSA). Little is known regarding the prevalence or clinical significance of the BORSA and MODSA strains. The most reliable in vitro susceptibility test methods for detecting MRSA (strains possessing PBP 2a) include the microdilution minimum inhibitory concentration (MIC) test (with 2% NaCl supplemented broth), the oxacillin agar screen plate test (incorporating 6 micrograms/ml oxacillin in 4% NaCl supplemented agar), and the National Committee for Clinical Laboratory Standards (NCCLS) disk diffusion test with oxacillin. All three methods use direct inoculum preparation and incubation of tests at 35 degrees C for a full 24 hours.

Molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from patients with bacteremia based on MLST, SCCmec, spa, and agr locus types analysis.

Science.gov (United States)

Goudarzi, Mehdi; Seyedjavadi, Sima Sadat; Nasiri, Mohammad Javad; Goudarzi, Hossein; Sajadi Nia, Raheleh; Dabiri, Hossein

2017-03-01

The widespread emergence of methicillin resistant Staphylococcus aureus, as a common cause of nosocomial infections, is becoming a serious concern in global public health. The objective of the present study was to investigate antimicrobial susceptibility pattern, frequency of virulence genes and molecular characteristics of methicillin-resistant Staphylococcus aureus strains isolated from patients with bacteremia. A total of 128 methicillin-resistant Staphylococcus aureus isolates were collected during February 2015 to January 2016. In vitro antimicrobial susceptibility of the isolates was assessed using the disk diffusion method. Conventional PCR was performed for the detection of adhesion (can, bbp, ebp, fnbB, fnbA, clfB, clfA) and toxin (etb, eta, pvl, tst) encoding genes, determining the agr type, SCCmec, MLST and spa typing of the isolates. All the methicillin-resistant Staphylococcus aureus isolates were found to be sensitive to linezolid, teicoplanin, and vancomycin. Resistance to the tested antibiotics varied from 97.7% for penicillin to 24.2% for mupirocin. The rate of multi drug resistance (MDR) in the present study was 97.7%. The most commonly detected toxin and adhesion genes were tst (58.6%), and clfB (100%), respectively. The majority of SCCmec III isolates were found in agr group I while SCCmec IV and II isolates were distributed among agr group III. Multilocus Sequence Typing (MLST) of the MRSA isolates showed five different sequence types: ST239 (43%), ST22 (39.8%), ST585 (10.9%), ST45 (3.9%) and ST240 (2.3%). All of the pvl positive strains belonged to ST22-SCCmec IV/t790 clone and were MDR. Among different 7 spa types, the most common were t790 (27.3%), t037 (21.9%), and t030 (14.1%). spa types t016, t924 and spa type t383 were reported for the first time from Asia and Iran, respectively. It was shown that spa types circulating in the studied hospitals varied which support the need to perform future surveillance studies in order to understand

Frequency of Reduced Vancomycin Susceptibility among Clinical Staphylococcus aureus Isolated in Ahvaz Iran

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Mojtaba Moosavian

2015-11-01

Full Text Available Introduction:   One   of   the   most   important   agents   in   hospital-acquired   infections   is Staphylococcus aureus. Treatment of methicillin-resistant S. aureus (MRSA infections with decreased susceptibility to vancomycin has recently been more difficult. The aim of this study was to evaluate the possible presence of vancomycin intermediate S. aureus (VISA and vancomycin- resistant S. aureus (VRSA and also to determine the frequency of MRSA in clinical specimens.Methods: In this study, 195 S. aureus isolates were collected from the patients were examined. All of the isolates were identified using standard biochemical tests.  Susceptibility of S. aureus isolates against 10 antibiotics was detected by disk diffusion method and was followed by E-test and vancomycin screen agar methods. Minimum inhibitory concentration (MIC of vancomycin was determined according to the CLSI guidelines.  Also, detection of mecA gene was performed by PCR and finally, the results were compared.Results: All of the isolates were susceptible to vancomycin (i.e. MIC range of vancomycin was between 0.25-2 µg/ml. Out of 195 S. aureus isolates, 99 isolates (50.8% were resistant to methicillin, and mecA gene was detected in 96 isolates. These results also showed that the highest and lowest resistance rate of isolates was to penicillin (96.9% and chloramphenicol (0%, respectively.Conclusion: Our findings showed that vancomycin can still be used as a valuable drug for treatment of S. aureus infections in our region. However, periodic evaluation of vancomycin MIC of S. aureus isolates is critical for monitoring MRSA and preventing the spread of VISA or VRSA among patients.

Evolutionary dynamics of methicillin-resistant Staphylococcus aureus within a healthcare system

NARCIS (Netherlands)

Hsu, Li-Yang; Harris, Simon R.; Chlebowicz, Monika A.; Lindsay, Jodi A.; Koh, Tse-Hsien; Krishnan, Prabha; Tan, Thean-Yen; Hon, Pei-Yun; Grubb, Warren B.; Bentley, Stephen D.; Parkhill, Julian; Peacock, Sharon J.; Holden, Matthew T. G.

2015-01-01

Background: In the past decade, several countries have seen gradual replacement of endemic multi-resistant healthcare-associated methicillin-resistant Staphylococcus aureus (MRSA) with clones that are more susceptible to antibiotic treatment. One example is Singapore, where MRSA ST239, the dominant

Treatment of methicillin-resistant Staphylococcus aureus in Latin America

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Carlos M Luna

Full Text Available The global spread of methicillin-resistant Staphylococcus aureus (MRSA means it is now a pathogen of worldwide public health concern. Within Latin America, MRSA is highly prevalent, with the proportion of S. aureus isolates that are methicillin-resistant on the rise, yet resources for managing the infection are limited. While several guidelines exist for the treatment of MRSA infections, many are written for the North American or European setting and need adaptation for use in Latin America. In this article, we aim to emphasize the importance of appropriate treatment of MRSA in the healthcare and community settings of Latin America. We present a summary of the available guidelines and antibiotics, and discuss particular considerations for clinicians treating MRSA in Latin America

Occurrence, species distribution, antimicrobial resistance and clonality of methicillin- and erythromycin-resistant staphylococci in the nasal cavity of domestic animals

DEFF Research Database (Denmark)

Bagcigil, Funda A.; Moodley, Arshnee; Baptiste, Keith E.

2007-01-01

beta-Lactams and macrolides are important antibiotics for treatment of staphylococcal infections in both humans and animals. The aim of the study was to investigate the occurrence, species distribution and clonality of methicillin and erythromycin-resistant staphylococci in the nasal cavity of dogs......, horses, pigs, and cattle in Denmark. Nasal swabs were collected from a total of 400 animals, including 100 individuals of each species. Methicillin and erythromycin-resistant staphylococci were isolated on selective media, identified by 16S rDNA sequencing, and typed by pulsed field gel electrophoresis...... (PFGE). Methicillin-resistant coagulase-negative staphylococci (MRCoNS) harbouring mecA were isolated from horses (50%) and dogs (13%), but not from food animals. The species identified were S. haemolyticus (n = 21), S. vitulinus (n = 19), S. sciuri (n = 13), S. epidermidis (n = 8), and S. warneri (n...

Prevalence of chlorhexidine-resistant methicillin-resistant Staphylococcus aureus following prolonged exposure.

Science.gov (United States)

Schlett, Carey D; Millar, Eugene V; Crawford, Katrina B; Cui, Tianyuan; Lanier, Jeffrey B; Tribble, David R; Ellis, Michael W

2014-08-01

Chlorhexidine has been increasingly utilized in outpatient settings to control methicillin-resistant Staphylococcus aureus (MRSA) outbreaks and as a component of programs for MRSA decolonization and prevention of skin and soft-tissue infections (SSTIs). The objective of this study was to determine the prevalence of chlorhexidine resistance in clinical and colonizing MRSA isolates obtained in the context of a community-based cluster-randomized controlled trial for SSTI prevention, during which 10,030 soldiers were issued chlorhexidine for body washing. We obtained epidemiological data on study participants and performed molecular analysis of MRSA isolates, including PCR assays for determinants of chlorhexidine resistance and high-level mupirocin resistance and pulsed-field gel electrophoresis (PFGE). During the study period, May 2010 to January 2012, we identified 720 MRSA isolates, of which 615 (85.4%) were available for molecular analysis, i.e., 341 clinical and 274 colonizing isolates. Overall, only 10 (1.6%) of 615 isolates were chlorhexidine resistant, including three from the chlorhexidine group and seven from nonchlorhexidine groups (P > 0.99). Five (1.5%) of the 341 clinical isolates and five (1.8%) of the 274 colonizing isolates harbored chlorhexidine resistance genes, and four (40%) of the 10 possessed genetic determinants for mupirocin resistance. All chlorhexidine-resistant isolates were USA300. The overall prevalence of chlorhexidine resistance in MRSA isolates obtained from our study participants was low. We found no association between extended chlorhexidine use and the prevalence of chlorhexidine-resistant MRSA isolates; however, continued surveillance is warranted, as this agent continues to be utilized for infection control and prevention efforts. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Emergence of ampicillin-resistant Enterococcus faecium in Danish hospitals

DEFF Research Database (Denmark)

Lester, Camilla H; Sandvang, Dorthe; Olsen, Stefan

2008-01-01

BACKGROUND: Ampicillin-resistant Enterococcus faecium isolates are reported in increasing numbers in many European hospitals. The clonal complex 17 (CC17) characterized by ampicillin resistance has been associated with nosocomial E. faecium outbreaks and infections in five continents. The aim...... in the number of infections caused by enterococci was observed from 2002 through 2006. The increase was mainly caused by E. faecium isolates, which tripled, whereas the number of E. faecalis isolates increased by only 23% during the same period. There was also a significant increase in the number of ampicillin......-resistant E. faecium isolates. MLST showed that 98% of the tested ampicillin-resistant E. faecium isolates belonged to CC17. PFGE showed eight different clusters and we found indications of clonal spread within the hospitals. CONCLUSIONS: Ampicillin-resistant E. faecium isolates have increased in frequency...

Molecular Analysis of Vancomycin-Resistant Enterococci Isolated from Regional Hospitals in Trinidad and Tobago

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Patrick E. Akpaka

2016-01-01

Full Text Available Geographic spread of vancomycin-resistant enterococci (VRE clones in cities, countries, or even continents has been identified by molecular techniques. This study aimed at characterizing virulent genes and determining genetic relatedness of 45 VRE isolates from Trinidad and Tobago using molecular tools, including polymerase chain reaction, pulsed-field gel electrophoresis (PFGE, and Random Amplification Polymorphic DNA (RAPD. The majority (84% of the isolates were Enterococcus faecium possessing vanA gene while the rest (16% were Enterococcus faecalis possessing vanB. The esp gene was found in all 45 VRE isolates while hyl genes were found only in E. faecium species. The E. faecium species expressed five distinct PFGE patterns. The predominant clones with similar or common patterns belonged to clones one and three, and each had 11 (29% of the VRE isolates. Plasmid content was identified in representative isolates from each clonal group. By contrast, the E. faecalis species had one PFGE pattern suggesting the presence of an occult and limited clonal spread. The emergence of VRE in the country seems to be related to intra/interhospital dissemination of an epidemic clone carrying the vanA element. Therefore, infection control measures will be warranted to prevent any potential outbreak and spread of VRE in the country.

The multifaceted resources and microevolution of the successful human and animal pathogen methicillin-resistant Staphylococcus aureus

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Agnes Marie Sá Figueiredo

2014-06-01

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA is one of the most important bacterial pathogens based on its incidence and the severity of its associated infections. In addition, severe MRSA infections can occur in hospitalised patients or healthy individuals from the community. Studies have shown the infiltration of MRSA isolates of community origin into hospitals and variants of hospital-associated MRSA have caused infections in the community. These rapid epidemiological changes represent a challenge for the molecular characterisation of such bacteria as a hospital or community-acquired pathogen. To efficiently control the spread of MRSA, it is important to promptly detect the mecA gene, which is the determinant of methicillin resistance, using a polymerase chain reaction-based test or other rapidly and accurate methods that detect the mecA product penicillin-binding protein (PBP2a or PBP2’. The recent emergence of MRSA isolates that harbour a mecA allotype, i.e., the mecC gene, infecting animals and humans has raised an additional and significant issue regarding MRSA laboratory detection. Antimicrobial drugs for MRSA therapy are becoming depleted and vancomycin is still the main choice in many cases. In this review, we present an overview of MRSA infections in community and healthcare settings with focus on recent changes in the global epidemiology, with special reference to the MRSA picture in Brazil.

The multifaceted resources and microevolution of the successful human and animal pathogen methicillin-resistant Staphylococcus aureus

Science.gov (United States)

Figueiredo, Agnes Marie Sá; Ferreira, Fabienne Antunes

2014-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important bacterial pathogens based on its incidence and the severity of its associated infections. In addition, severe MRSA infections can occur in hospitalised patients or healthy individuals from the community. Studies have shown the infiltration of MRSA isolates of community origin into hospitals and variants of hospital-associated MRSA have caused infections in the community. These rapid epidemiological changes represent a challenge for the molecular characterisation of such bacteria as a hospital or community-acquired pathogen. To efficiently control the spread of MRSA, it is important to promptly detect the mecA gene, which is the determinant of methicillin resistance, using a polymerase chain reaction-based test or other rapidly and accurate methods that detect the mecA product penicillin-binding protein (PBP)2a or PBP2’. The recent emergence of MRSA isolates that harbour a mecA allotype, i.e., the mecC gene, infecting animals and humans has raised an additional and significant issue regarding MRSA laboratory detection. Antimicrobial drugs for MRSA therapy are becoming depleted and vancomycin is still the main choice in many cases. In this review, we present an overview of MRSA infections in community and healthcare settings with focus on recent changes in the global epidemiology, with special reference to the MRSA picture in Brazil. PMID:24789555

Serine and alanine racemase activities of VanT: a protein necessary for vancomycin resistance in Enterococcus gallinarum BM4174.

Science.gov (United States)

Arias, C A; Weisner, J; Blackburn, J M; Reynolds, P E

2000-07-01

Vancomycin resistance in Enterococcus gallinarum results from the production of UDP-MurNAc-pentapeptide[D-Ser]. VanT, a membrane-bound serine racemase, is one of three proteins essential for this resistance. To investigate the selectivity of racemization of L-Ser or L-Ala by VanT, a strain of Escherichia coli TKL-10 that requires D-Ala for growth at 42 degrees C was used as host for transformation experiments using plasmids containing the full-length vanT from Ent. gallinarum or the alanine racemase gene (alr) of Bacillus stearothermophilus: both plasmids were able to complement E. coli TKL-10 at 42 degrees C. No alanine or serine racemase activities were detected in the host strain E. coli TKL-10 grown at 30, 34 or 37 degrees C. Serine and alanine racemase activities were found almost exclusively (96%) in the membrane fraction of E. coli TKL-10/pCA4(vanT): the alanine racemase activity of VanT was 14% of the serine racemase activity in both E. coli TKL-10/pCA4(vanT) and E. coli XL-1 Blue/pCA4(vanT). Alanine racemase activity was present mainly (95%) in the cytoplasmic fraction of E. coli TKL-10/pJW40(alr), with a trace (1.6%) of serine racemase activity. Additionally, DNA encoding the soluble domain of VanT was cloned and expressed in E. coli M15 as a His-tagged polypeptide and purified: this polypeptide also exhibited both serine and alanine racemase activities; the latter was approximately 18% of the serine racemase activity, similar to that of the full-length, membrane-bound enzyme. N-terminal sequencing of the purified His-tagged polypeptide revealed a single amino acid sequence, indicating that the formation of heterodimers between subunits of His-tagged C-VanT and endogenous alanine racemases from E. coli was unlikely. The authors conclude that the membrane-bound serine racemase VanT also has alanine racemase activity but is able to racemize serine more efficiently than alanine, and that the cytoplasmic domain is responsible for the racemase activity.

Genetic Determinants of High-Level Oxacillin Resistance in Methicillin-Resistant Staphylococcus aureus.

Science.gov (United States)

Pardos de la Gandara, Maria; Borges, Vitor; Chung, Marilyn; Milheiriço, Catarina; Gomes, João Paulo; de Lencastre, Herminia; Tomasz, Alexander

2018-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) strains carry either a mecA - or a mecC -mediated mechanism of resistance to beta-lactam antibiotics, and the phenotypic expression of resistance shows extensive strain-to-strain variation. In recent communications, we identified the genetic determinants associated with the stringent stress response that play a major role in the antibiotic resistant phenotype of the historically earliest "archaic" clone of MRSA and in the mecC -carrying MRSA strain LGA251. Here, we sought to test whether or not the same genetic determinants also contribute to the resistant phenotype of highly and homogeneously resistant (H*R) derivatives of a major contemporary MRSA clone, USA300. We found that the resistance phenotype was linked to six genes ( fruB , gmk , hpt , purB , prsA , and relA ), which were most frequently targeted among the analyzed 20 H*R strains (one mutation per clone in 19 of the 20 H*R strains). Besides the strong parallels with our previous findings (five of the six genes matched), all but one of the repeatedly targeted genes were found to be linked to guanine metabolism, pointing to the key role that this pathway plays in defining the level of antibiotic resistance independent of the clonal type of MRSA. Copyright © 2018 American Society for Microbiology.

Synthetic analogs of anoplin show improved antimicrobial activities

DEFF Research Database (Denmark)

Munk, Jens; Uggerhøj, Lars Erik; Poulsen, Tanja Juul

2013-01-01

We present the antimicrobial and hemolytic activities of the decapeptide anoplin and 19 analogs thereof tested against methicillin-resistant Staphylococcus aureus ATCC 33591 (MRSA), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), vancomycin-resistant Enterococcus faecium (ATCC...... that increasing the charge and/or hydrophobicity improves antimicrobial activity and increases hemolytic activity. For each strain tested, we identify at least six anoplin analogs with an improved therapeutic index compared with anoplin, the only exception being Enterococcus faecium, against which only few...

Zinc Resistance within Swine-Associated Methicillin-Resistant Staphylococcus aureus Isolates in the United States Is Associated with Multilocus Sequence Type Lineage.

Science.gov (United States)

Hau, Samantha J; Frana, Timothy; Sun, Jisun; Davies, Peter R; Nicholson, Tracy L

2017-08-01

Zinc resistance in livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) sequence type 398 (ST398) is primarily mediated by the czrC gene colocated with the mecA gene, encoding methicillin resistance, within the type V staphylococcal cassette chromosome mec (SCC mec ) element. Because czrC and mecA are located within the same mobile genetic element, it has been suggested that the use of zinc in feed as an antidiarrheal agent has the potential to contribute to the emergence and spread of methicillin-resistant S. aureus (MRSA) in swine, through increased selection pressure to maintain the SCC mec element in isolates obtained from pigs. In this study, we report the prevalence of the czrC gene and phenotypic zinc resistance in U.S. swine-associated LA-MRSA ST5 isolates, MRSA ST5 isolates from humans with no swine contact, and U.S. swine-associated LA-MRSA ST398 isolates. We demonstrated that the prevalence of zinc resistance in U.S. swine-associated LA-MRSA ST5 isolates was significantly lower than the prevalence of zinc resistance in MRSA ST5 isolates from humans with no swine contact and swine-associated LA-MRSA ST398 isolates, as well as prevalences from previous reports describing zinc resistance in other LA-MRSA ST398 isolates. Collectively, our data suggest that selection pressure associated with zinc supplementation in feed is unlikely to have played a significant role in the emergence of LA-MRSA ST5 in the U.S. swine population. Additionally, our data indicate that zinc resistance is associated with the multilocus sequence type lineage, suggesting a potential link between the genetic lineage and the carriage of resistance determinants. IMPORTANCE Our data suggest that coselection thought to be associated with the use of zinc in feed as an antimicrobial agent is not playing a role in the emergence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) ST5 in the U.S. swine population. Additionally, our data indicate

Significant reduction in vancomycin-resistant enterococcus colonization and bacteraemia after introduction of a bleach-based cleaning-disinfection programme.

Science.gov (United States)

Grabsch, E A; Mahony, A A; Cameron, D R M; Martin, R D; Heland, M; Davey, P; Petty, M; Xie, S; Grayson, M L

2012-12-01

Vancomycin-resistant enterococcus (VRE) colonization and infection have increased at our hospital, despite adherence to standard VRE control guidelines. We implemented a multi-modal, hospital-wide improvement programme including a bleach-based cleaning-disinfection programme ('Bleach-Clean'). VRE colonization, infection and environmental contamination were compared pre and post implementation. The programme included a new product (sodium hypochlorite 1000 ppm + detergent), standardized cleaning-disinfection practices, employment of cleaning supervisors, and modified protocols to rely on alcohol-based hand hygiene and sleeveless aprons instead of long-sleeved gowns and gloves. VRE was isolated using chromogenic agar and/or routine laboratory methods. Outcomes were assessed during the 6 months pre and 12 months post implementation, including proportions (per 100 patients screened) of VRE colonization in high-risk wards (HRWs: intensive care, liver transplant, renal, haematology/oncology); proportions of environmental contamination; and episodes of VRE bacteraemia throughout the entire hospital. Significant reductions in newly recognized VRE colonizations (208/1948 patients screened vs 324/4035, a 24.8% reduction, P = 0.001) and environmental contamination (66.4% reduction, P = 0.012) were observed, but the proportion of patients colonized on admission was stable. The total burden of inpatients with VRE in the HRWs also declined (median percentage of colonized inpatients per week, 19.4% vs 17.3%, P = 0.016). Hospital-wide VRE bacteraemia declined from 14/2935 patients investigated to 5/6194 (83.1% reduction; P Clean programme was associated with marked reductions in new VRE colonizations in high-risk patients, and VRE bacteraemia across the entire hospital. These findings have important implications for VRE control in endemic healthcare settings. Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

SURVEILLANCE AND CONTROL OF ANTIBIOTIC RESISTANCE IN THE MEDITERRANEAN REGION

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Walter Ricciardi

2016-07-01

Full Text Available Antibiotic resistance is one of the most relevant problems in the healthcare: the growth of resistant micro-organisms in healthcare settings is a worrisome threat, raising length to stay (LOS, morbidity and mortality in those patients. The importance of the antibiotic resistance and its spread around the world, gave rise to the activation of several surveillance systems, based especially on the collection of laboratory data to local or national level. The objective of this work is to carry out a review of the scientific literature existing on the topic and scientific activities related to surveillance on antibiotic resistance in countries bordering the Mediterranean Sea. Recent Data from European Centre for Disease Prevention and Control (November 2015 show, for different combinations bacterium-drug, an increase of resistance from North to South and from West to East of Europe; it is particularly worrying the phenomenon of resistance carried out by some gram negative, specifically Klebsiella pneumoniae and Escherichia coli to third-generation cephalosporin, often combined in opposition to fluoroquinolones and amino glycosides. Is particularly relevant the incidence of resistance to carbapenems by strains of Enterobacteriaceae (Klebsiella included. The resistance exerted by MRSA (Methicillin-resistant Staphylococcus aureus continues to be relevant, albeit showing some decline in recent years. The incidence of resistance carried on by Streptococcus pneumoniae is stable and is mainly relevant to macrolides. Finally, a significant increase in recording relatively exercised by Enterococcus faecium to Vancomycin. Detecting, preventing, and controlling antibiotic resistance requires strategic, coordinated, and sustained efforts. It also depends on the engagement of governments, academia, industry, healthcare providers, the general public, and the agricultural community, as well as international partners. Committing to combating antibiotic-resistant

Spontaneous methicillin-resistant Staphylococcus aureus (MRSA) meningitis.

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Longhurst, William D; Sheele, Johnathan M

2018-05-01

Spontaneous methicillin-resistant Staphylococcus aureus (MRSA) meningitis is extremely rare and has a high mortality rate. We report a case of MRSA meningitis in an otherwise healthy young adult female with no recent trauma or neurosurgical interventions. Despite antibiotics she suffered a vasculitis-induced cerebral vascular ischemic event. Copyright © 2018 Elsevier Inc. All rights reserved.

Vancomycin-induced thrombocytopenia in a 60-year-old man: a case report

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Shah Ravish A

2009-06-01

Full Text Available Abstract Introduction Vancomycin, a glycopeptide antibiotic, is used to treat resistant gram-positive infections. There has been a 10- to 20-fold increase in its use over the past 25 years. Although ototoxicity and nephrotoxicity are well known side effects of vancomycin, it can also induce platelet reactive antibodies leading to life-threatening thrombocytopenia. Vancomycin is often clinically overlooked as a cause of thrombocytopenia, especially in a scenario of sepsis or when there is use of heparin. We report a proven case of vancomycin-induced thrombocytopenia and its reversal after discontinuation of vancomycin. Case presentation A 60-year-old man with a history of hypertension, congestive heart failure and dyslipidemia was admitted for a right shoulder rotator cuff tear. He underwent right-shoulder arthroscopy and rotator cuff repair. About three weeks later, he developed pain, swelling and purulent drainage from his right shoulder. Arthroscopic irrigation and drainage was then performed. Intraoperative fluid revealed the presence of Methicillin susceptible Staphylococcus aureus, vancomycin-sensitive Enterococcus spp. and Serratia marcescens. The patient had no known allergies. After reviewing his antimicrobial susceptibility, he was started on vancomycin 1500 mgs intravenously every 12 hours (to treat both Staphylococcus aureus and Enterococcus spp and ciprofloxacin 750 mgs by oral induction every 12 hours. The patient's condition improved following antibiotic treatment. He was discharged and allowed to go home on IV vancomycin and oral ciprofloxacin. The patient's platelet count on the day of starting vancomycin therapy was 253 × 103/mm3. At weeks one, two and three, the counts were 231 × 103/mm3, 272 × 103/mm and 6 × 103/mm3, respectively. The patient was admitted for further work-up of the thrombocytopenia. He was later shown to have vancomycin-induced platelet-reactive antibodies, causing significant thrombocytopenia, and then

Next-Generation Sequence Analysis Reveals Transfer of Methicillin Resistance to a Methicillin-Susceptible Staphylococcus aureus Strain That Subsequently Caused a Methicillin-Resistant Staphylococcus aureus Outbreak: a Descriptive Study.

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Weterings, Veronica; Bosch, Thijs; Witteveen, Sandra; Landman, Fabian; Schouls, Leo; Kluytmans, Jan

2017-09-01

Resistance to methicillin in Staphylococcus aureus is caused primarily by the mecA gene, which is carried on a mobile genetic element, the staphylococcal cassette chromosome mec (SCC mec ). Horizontal transfer of this element is supposed to be an important factor in the emergence of new clones of methicillin-resistant Staphylococcus aureus (MRSA) but has been rarely observed in real time. In 2012, an outbreak occurred involving a health care worker (HCW) and three patients, all carrying a fusidic acid-resistant MRSA strain. The husband of the HCW was screened for MRSA carriage, but only a methicillin-susceptible S. aureus (MSSA) strain, which was also resistant to fusidic acid, was detected. Multiple-locus variable-number tandem-repeat analysis (MLVA) typing showed that both the MSSA and MRSA isolates were MT4053-MC0005. This finding led to the hypothesis that the MSSA strain acquired the SCC mec and subsequently caused an outbreak. To support this hypothesis, next-generation sequencing of the MSSA and MRSA isolates was performed. This study showed that the MSSA isolate clustered closely with the outbreak isolates based on whole-genome multilocus sequence typing and single-nucleotide polymorphism (SNP) analysis, with a genetic distance of 17 genes and 44 SNPs, respectively. Remarkably, there were relatively large differences in the mobile genetic elements in strains within and between individuals. The limited genetic distance between the MSSA and MRSA isolates in combination with a clear epidemiologic link supports the hypothesis that the MSSA isolate acquired a SCC mec and that the resulting MRSA strain caused an outbreak. Copyright © 2017 American Society for Microbiology.

High prevalence of multidrug-resistant MRSA in a tertiary care hospital of northern India

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Hare Krishna Tiwari

2008-11-01

Full Text Available Hare Krishna Tiwari1, Darshan Sapkota2, Malaya Ranjan Sen11Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, UP, India; 2Department of Microbiology, Universal College of Medical Sciences, Bhairahawa, NepalAbstract: Methicillin-resistant Staphylococcus aureus (MRSA is an important nosocomial and community pathogen. The objectives of this study were to estimate the prevalence of multidrug-resistant MRSA strains in clinical specimens and to investigate the sensitivity pattern of these strains against various antibiotics used for treating hospitalized and out patients. Strains were identified using standard procedures, and their sensitivity pattern was investigated using such techniques as disc diffusion, minimum inhibitory concentration (MIC, and the mecA gene PCR. Among 783 isolates of S. aureus, 301 (38.44% were methicillin-resistant, of which 217 (72.1% were found to be multidrug-resistant. Almost all MRSA strains were resistant to penicillin, 95.68% were resistant to cotrimoxazole, 92.36% were resistant to chloramphenicol, 90.7% were resistant to norfloxacin, 76.1% were resistant to tetracycline, and 75.75% were resistant to ciprofloxacin. Vancomycin was the most effective drug, with only 0.33% of MRSA strains being resistant to it. It is concluded that antibiotics other than vancomycin can be used as anti-MRSA agents after a sensitivity test so as to preclude the emergence of resistance to it and that prevailing problems in chemotherapy will escalate unless indiscriminate and irrational usage of antibiotics is checked.Keywords: multidrug-resistant MRSA, prevalence, India

Methicillin-resistant Staphylococcus aureus transmission

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Andersen, Leif Percival; Nielsen, Xiaohui

2015-01-01

INTRODUCTION: Even though methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of nosocomial infections, it may often be difficult to evaluate the exact route of transmission. METHODS: In this study, we describe four cases of nosocomial transmission of MRSA in a hospital with a low...... increase the risk of contaminating hands, arms and the front of the uniform. Hand hygiene is therefore essential, but the use of protection gowns with long sleeves is also important in order to prevent transmission of MRSA. After culture of MRSA and implementation of specific precautions to prevent...

In-vitro antioxidant and antibacterial activities of Xanthium strumarium L. extracts on methicillin-susceptible and methicillin-resistant Staphylococcus aureus.

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Rad, Javad Sharifi; Alfatemi, Seyedeh Mahsan Hoseini; Rad, Majid Sharifi; Iriti, Marcello

2013-10-01

The excessive and repeated use of antibiotics in medicine has led to the development of antibiotic-resistant microbial strains, including Staphylococcus aureus whose emergence of antibiotic-resistant strains has reduced the number of antibiotics available to treat clinical infections caused by this bacterium. In this study, antioxidant and antimicrobial activities of methanolic extract of Xanthium strumarium L. leaves were evaluated on methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MRSA) spp. Antiradical and antioxidant activities X. strumarium L. leaf extract were evaluated based on its ability to scavenge the synthetic 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical and by the paired diene method, respectively, whereas the antimicrobial activity was assayed by the disc diffusion method. Data were subjected to analysis of variance following an entirely random design to determine the least significant difference at P strumarium extract affected both methicillin-sensitive Staphylococcus aureus and MRSA, though antibacterial activity was more effective on methicillin-susceptible S. aureus spp. The antibacterial and antioxidant activities exhibited by the methanol extract may justify the traditional use of this plant as a folk remedy worldwide.

Toxin Mediates Sepsis Caused by Methicillin-Resistant Staphylococcus epidermidis.

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Li Qin

2017-02-01

Full Text Available Bacterial sepsis is a major killer in hospitalized patients. Coagulase-negative staphylococci (CNS with the leading species Staphylococcus epidermidis are the most frequent causes of nosocomial sepsis, with most infectious isolates being methicillin-resistant. However, which bacterial factors underlie the pathogenesis of CNS sepsis is unknown. While it has been commonly believed that invariant structures on the surface of CNS trigger sepsis by causing an over-reaction of the immune system, we show here that sepsis caused by methicillin-resistant S. epidermidis is to a large extent mediated by the methicillin resistance island-encoded peptide toxin, PSM-mec. PSM-mec contributed to bacterial survival in whole human blood and resistance to neutrophil-mediated killing, and caused significantly increased mortality and cytokine expression in a mouse sepsis model. Furthermore, we show that the PSM-mec peptide itself, rather than the regulatory RNA in which its gene is embedded, is responsible for the observed virulence phenotype. This finding is of particular importance given the contrasting roles of the psm-mec locus that have been reported in S. aureus strains, inasmuch as our findings suggest that the psm-mec locus may exert effects in the background of S. aureus strains that differ from its original role in the CNS environment due to originally "unintended" interferences. Notably, while toxins have never been clearly implied in CNS infections, our tissue culture and mouse infection model data indicate that an important type of infection caused by the predominant CNS species is mediated to a large extent by a toxin. These findings suggest that CNS infections may be amenable to virulence-targeted drug development approaches.

Increasing Resistance to Extended-Spectrum Cephalosporins, Fluoroquinolone, and Carbapenem in Gram-Negative Bacilli and the Emergence of Carbapenem Non-Susceptibility in Klebsiella pneumoniae: Analysis of Korean Antimicrobial Resistance Monitoring System (KARMS) Data From 2013 to 2015.

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Kim, Dokyun; Ahn, Ji Young; Lee, Chae Hoon; Jang, Sook Jin; Lee, Hyukmin; Yong, Dongeun; Jeong, Seok Hoon; Lee, Kyungwon

2017-05-01

National surveillance of antimicrobial resistance becomes more important for the control of antimicrobial resistance and determination of treatment guidelines. We analyzed Korean Antimicrobial Resistance Monitoring System (KARMS) data collected from 2013 to 2015. Of the KARMS participants, 16 secondary or tertiary hospitals consecutively reported antimicrobial resistance rates from 2013 to 2015. Data from duplicate isolates and institutions with fewer than 20 isolates were excluded. To determine the long-term trends, previous KARMS data from 2004 to 2012 were also considered. The prevalence of methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium from 2013 to 2015 was 66-72% and 29-31%, respectively. The resistance rates of Escherichia coli to cefotaxime and cefepime gradually increased to 35% and 31%, respectively, and fluoroquinolone resistance reached 48% in 2015. The resistance rates of Klebsiella pneumoniae to cefotaxime, cefepime, and carbapenem were 38-41%, 33-41%, and carbapenem susceptibility rates of E. coli and K. pneumoniae decreased from 100% and 99.3% in 2011 to 99.0% and 97.0% in 2015, respectively. The resistance rate of Pseudomonas aeruginosa to carbapenem increased to 35% and the prevalence of carbapenem-resistant Acinetobacter baumannii increased from 77% in 2013 to 85% in 2015. Between 2013 and 2015, the resistance rates of E. coli to third- and fourth-generation cephalosporins increased continuously, while carbapenem-susceptibility gradually decreased, particularly in K. pneumoniae. The prevalence of carbapenem-resistant P. aeruginosa and A. baumannii increased significantly; therefore, few treatment options remain for these resistant strains. © The Korean Society for Laboratory Medicine

Heavy metal and disinfectant resistance genes among livestock-associated methicillin-resistant Staphylococcus aureus isolates

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Argudin, Maria Angeles; Lauzat, Birgit; Kraushaar, Britta

2016-01-01

Livestock associated methicillin-resistant Staphylococcus aureus (LA-MRSA) has emerged in animal production worldwide. Most LA-MRSA in Europe belong to the clonal complex (CC)398. The reason for the LA-MRSA emergence is not fully understood. Besides antimicrobial agents used for therapy, other su...

Characterisation of the selective binding of antibiotics vancomycin and teicoplanin by the VanS receptor regulating type A vancomycin resistance in the enterococci.

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Hughes, C S; Longo, E; Phillips-Jones, M K; Hussain, R

2017-08-01

A-type resistance towards "last-line" glycopeptide antibiotic vancomycin in the leading hospital acquired infectious agent, the enterococci, is the most common in the UK. Resistance is regulated by the VanR A S A two-component system, comprising the histidine sensor kinase VanS A and the partner response regulator VanR A . The nature of the activating ligand for VanS A has not been identified, therefore this work sought to identify and characterise ligand(s) for VanS A . In vitro approaches were used to screen the structural and activity effects of a range of potential ligands with purified VanS A protein. Of the screened ligands (glycopeptide antibiotics vancomycin and teicoplanin, and peptidoglycan components N-acetylmuramic acid, D-Ala-D-Ala and Ala-D-y-Glu-Lys-D-Ala-D-Ala) only glycopeptide antibiotics vancomycin and teicoplanin were found to bind VanS A with different affinities (vancomycin 70μM; teicoplanin 30 and 170μM), and were proposed to bind via exposed aromatic residues tryptophan and tyrosine. Furthermore, binding of the antibiotics induced quicker, longer-lived phosphorylation states for VanS A , proposing them as activators of type A vancomycin resistance in the enterococci. Copyright © 2017 Diamond Light Source Ltd. Published by Elsevier B.V. All rights reserved.

Horizontal transfer of antibiotic resistance from Enterococcus faecium of fermented meat origin to clinical isolates of E. faecium and Enterococcus faecalis.

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Jahan, Musarrat; Zhanel, George G; Sparling, Richard; Holley, Richard A

2015-04-16

Enterococcus species are part of the normal intestinal flora of a large number of mammals including humans and consequently, they can be used as indicators of faecal contamination in food and water for human consumption. Their presence in large numbers in foods may indicate a lapse in sanitation and their ability to serve as a genetic reservoir of transferable antibiotic resistance is of concern. In the present study, Enterococcus spp., isolated from commercially fermented meat and human clinical specimen were studied to determine genetic relationships. SmaI pulsed-field gel electrophoresis (PFGE) patterns exhibited genomic heterogeneity within and between both groups of isolates. However, in spite of this heterogeneity there were still substantial phenotypic similarities which suggested that food might be a potential vehicle for distribution of resistant bacteria among humans. In vitro conjugation experiments demonstrated transfer of the tetracycline resistant determinant, tet(M), from Enterococcus faecium S27 isolated from fermented sausage to clinical isolates of both E. faecium and Enterococcus faecalis. The streptomycin resistance of E. faecium S27 was also transferred to a clinical strain, E. faecalis 82916, which was confirmed by the presence of the streptomycin resistance gene, aadA, in the donor and transconjugant strains. Since the aadA gene is associated with a class 1 integron, results also suggested that resistance transfer might have occurred via an integron. It appears this is the first identification of a class 1 integron in E. faecium isolated from food. The importance of food enterococci as a reservoir of antibiotic resistance genes and the potential for their genetic transfer to human strains following consumption of uncooked or undercooked contaminated meat is underlined by this work. Copyright © 2015 Elsevier B.V. All rights reserved.

Methicillin-resistant Staphylococcus aureus: Prevalence, incidence, risk factors, and effects on survival of patients in a specialist palliative care unit: A prospective observational study.

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Gleeson, Aoife; Larkin, Philip; Walsh, Cathal; O'Sullivan, Niamh

2016-04-01

Little is known about the impact of methicillin-resistant Staphylococcus aureus in palliative care settings. To date, the clinical impact of methicillin-resistant Staphylococcus aureus in palliative care is unknown. To determine prevalence and incidence of methicillin-resistant Staphylococcus aureus colonisation in a specialist palliative care setting, to identify risk factors for methicillin-resistant Staphylococcus aureus colonisation, to determine the eradication success rate and to determine the impact of methicillin-resistant Staphylococcus aureus on survival. Prospective cohort study. Data were collected for consecutive admissions to an inpatient palliative care service. Patients were screened for methicillin-resistant Staphylococcus aureus colonisation on admission and 1 week post admission. Methicillin-resistant Staphylococcus aureus eradication was attempted in methicillin-resistant Staphylococcus aureus positive patients. Data were collected from 609 admissions for 466 individual patients. Admission screening data were available in 95.5%. Prevalence of methicillin-resistant Staphylococcus aureus colonisation was 11.59% (54 patients). One week incidence of methicillin-resistant Staphylococcus aureus colonisation was 1.2%. Risk factors for methicillin-resistant Staphylococcus aureus colonisation were determined using Chi-Squared test and included high Waterlow score (p resistant Staphylococcus aureus status prior to admission (p resistant Staphylococcus aureus was eradicated in 8.1% of admissions, while 46 patients commenced on the protocol (62.2%) died before completing it. Methicillin-resistant Staphylococcus aureus did not significantly impact survival but was significantly associated with having infection episodes and longer length of stay. This study identified risk factors for methicillin-resistant Staphylococcus aureus colonisation in palliative care patients. Methicillin-resistant Staphylococcus aureus was eradicated in 8.1% of patients. Hence

[Molecular characterization of resistance mechanisms: methicillin resistance Staphylococcus aureus, extended spectrum β-lactamases and carbapenemases].

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Oteo, Jesús; Belén Aracil, María

2015-07-01

Multi-drug resistance in bacterial pathogens increases morbidity and mortality in infected patients and it is a threat to public health concern by their high capacity to spread. For both reasons, the rapid detection of multi-drug resistant bacteria is critical. Standard microbiological procedures require 48-72 h to provide the antimicrobial susceptibility results, thus there is emerging interest in the development of rapid detection techniques. In recent years, the use of selective and differential culture-based methods has widely spread. However, the capacity for detecting antibiotic resistance genes and their low turnaround times has made molecular methods a reference for diagnosis of multidrug resistance. This review focusses on the molecular methods for detecting some mechanisms of antibiotic resistance with a high clinical and epidemiological impact: a) Enzymatic resistance to broad spectrum β-lactam antibiotics in Enterobacteriaceae, mainly extended spectrum β-lactamases (ESBL) and carbapenemases; and b) methicillin resistance in Staphylococcus aureus. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

Methicillin-resistant Staphylococcus aureus nasal carriage between healthy students of medical and nonmedical universities.

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Abroo, Soleiman; Hosseini Jazani, Nima; Sharifi, Yaeghob

2017-07-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a challenge for public health, and community-acquired (CA) infections seem to be increasing among people in different areas. A total of 700 healthy student volunteers residing in dormitories of universities in Urmia, Iran, were enrolled in this study. After identification of the isolates, antibiotic susceptibility, presence of mecA and pvl genes, and staphylococcal cassette chromosome mec (SCCmec) typing were evaluated. Nasal screening identified 137 (19.6%) carriers of S aureus, and 18 (13.14%) were MRSA isolates. The antimicrobial susceptibility patterns of isolates revealed high resistance to penicillin (93.4%). All isolates were sensitive to vancomycin. The SCCmec typing showed that most MRSA strains belonged to SCCmec type IV (n = 14; 77.8%). Only 1 (5.56%) MRSA isolates carried the pvl gene. Our findings revealed the relatively high frequency of S aureus nasal carriers and the advent of multidrug resistance among these isolates. Most MRSA isolates were SCCmec type IV; the transfer of such MRSA strains from carriers to other individuals in crowded living conditions such as dormitories can act as a risk factor for outbreak of CA MRSA and is a serious threat for the study groups. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Methicillin-resistant Staphylococcus aureus in Pig Farming

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Voss, Andreas; Loeffen, Frans; Bakker, Judith; Klaassen, Corne; Wulf, Mireille

2005-01-01

We conducted a study among a group of 26 regional pig farmers to determine the methicillin-resistant Staphylococcus aureus prevalence rate and found it was >760 times greater than the rate of patients admitted to Dutch hospitals. While spa-type t108 is apparently a more widespread clone among pig farmers and their environment, we did find other spa-types.

Antibiotic Susceptibility Pattern of Gram-positive Cocci Cultured from Patients in Three University Hospitals in Tehran, Iran during 2001-2005

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Aligholi Marzieh

2009-10-01

Full Text Available Bacterial resistance to antibiotics is a serious problem and is increasing in prevalence world-wide at an alarming rate. The antimicrobial susceptibility patterns of 1897 gram-positive bacterial Isolates were evaluated. The minimum inhibitory concentration (MIC of isolates which comprised Staphylococcus aureus (927 isolates, coagulase-negative staphylococci (CNS; 425 isolates, Enterococcus faecalis (320 isolates, Enterococcus faecium (157 isolates, and pneumococci (50 isolates collected from 3 teaching hospitals in Tehran were determined by agar dilution method according to Clinical and Laboratory Standards Institute (CLSI guidelines. The presence of mecA gene was investigated in methicillin-resistant staphylococci by PCR method and vanA and vanB genes were targeted in enterococcal isolates by Multiplex PCR method. The resistance rate to methicillin among S. aureus and CNS isolates were 33% and 49%, respectively. All S. aureus isolates were susceptible to vancomycin .The lowest rate of resistance in all S. aureus isolates was found for rifampicin (<4%. The vancomycin resistance rate in enterococci isolates was 11% which was more frequent among E. faecium (19% than E. faecalis (4%, all resistant isolates carrying vanA. High-level resistance to gentamicin and streptomycin, were detected in 47% and 87% of enterococcal isolates respectively. The rate of penicillin resistance in pneumococci was 3% and about 27% of isolates had reduced susceptibility to penicillin. The prevalence of erythromycin resistant among pneumococci was 58%. All pneumococcal isolates were susceptible to ceftriaxone, rifampicin and vancomycin. Our data highlight the importance of access to updated bacterial susceptibility data regarding commonly prescribed agents for clinicians in Iran.

Characterization of transferable tetracycline resistance genes in Enterococcus faecalis isolated from raw food

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Wilcks, Andrea; Andersen, Sigrid Rita; Licht, Tine Rask

2005-01-01

The prevalence of tetracycline resistance, and of specific genetic determinants for this resistance was investigated in 1003 strains of Enterococcus faecalis isolated from various raw food products originating from five categories including chicken meat, other poultry meat, beef, pork, and 'other...

Presence of antiseptic resistance genes in porcine methicillin-resistant Staphylococcus aureus.

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Wong, T Z; Zhang, M; O'Donoghue, M; Boost, M

2013-03-23

Numerous studies have documented the presence of methicillin-resistant Staphylococcus aureus (MRSA) in meat-producing animals, which has led to concern about its spread into the community. Disinfectants play an important role in reduction of contamination in both animal husbandry and food-preparation, helping control spread of organisms from foodstuffs, including raw meat. Plasmid-borne antiseptic resistance (AR) genes increasing tolerance to several disinfectants have been reported in S. aureus of human origin (qacA/B and smr) and from bovine, equine, and caprine staphylococcal isolates (qacG, qacH, and qacJ). This study investigated the presence of AR genes in porcine MRSA isolates. Plasmid DNA from 100 MRSA ST9 strains isolated from pig carcasses was amplified for the presence of AR genes. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) to benzalkonium chloride (BC) and chlorhexidine gluconate (CHX) were determined in AR gene-positive isolates. qacG was present in 45 strains, eight of which also harbored smr. No strains carried qacA/B, qacH or qacJ. Presence of smr increased MICs to both BC and CHX and MBCs of CHX, but qacG presence only resulted in elevated MBC for CHX. This is the first report of AR genes from a porcine source. AR gene positivity has previously been associated with methicillin resistance and AR gene presence in these strains may increase their ability to persist in the environment. Improved implementation of hygiene measures during transportation and pre- and post-slaughter should be considered to prevent spread in the community. Copyright © 2012 Elsevier B.V. All rights reserved.

High prevalence of methicillin-resistant coagulase-negative staphylococci isolated from a university environment in Thailand.

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Seng, Rathanin; Leungtongkam, Udomluk; Thummeepak, Rapee; Chatdumrong, Wassana; Sitthisak, Sutthirat

2017-06-01

The present study was conducted to isolate and characterize the molecular epidemiology of the methicillin-resistant staphylococci in the general university environment, where all five locations; the library, restrooms, canteens, computer rooms and outdoor surfaces, are in common use by a large population of students. We used Mannitol Salt Agar (MSA) supplemented with 4 μg/ml of oxacillin to screen the methicillin-resistant staphylococci. The species level was identified by PCR of rdr (Staphylococcus epidermidis), groESL (Staphylococcus haemolyticus) and nuc (Staphylococcus aureus and Staphylococcus warneri) genes and DNA sequencing of tuf and dnaJ genes. The susceptibility patterns of the isolates were determined using the disk diffusion method. Antibiotic and disinfectant resistance genes, together with SCCmec types, were detected by the PCR method. The methicillin resistant-staphylococci were isolated from 41 of 200 samples (20.5%), and all of them were found to be methicillin-resistant coagulase negative staphylococci (MR-CoNS). The library had the highest percentage of contamination, with 43.3% of the samples found to be contaminated. All isolates belonged to 6 different species including S. haemolyticus, S. epidermidis, S. warneri, S. cohnii, S. saprophyticus and S. hominis. The antimicrobial resistance rates were highest against penicillin (100%), then cefoxitin (73.1%), erythromycin (73.1%) and oxacillin (68.3%). Altogether, the isolates were approximately 61.0% multidrug resistant (MDR), with the S. epidermidis isolates being the most multidrug resistant. The prevalence of the qacA/B gene was detected in 63.4% of the isolates, and SCCmec could be typed in 43.9% (18/41) of the isolates. The type range was: II (n = 1), IVd (n = 1), I (n = 2), V (n = 6), IVa (n = 8) and untypeable (n = 23). This result indicates that these university environments are contaminated with methicillin-resistant coagulase negative staphylococci that carry various SCCmec types and

Zinc resistance of Staphylococcus aureus of animal origin is strongly associated with methicillin resistance

DEFF Research Database (Denmark)

Cavaco, Lina; Hasman, Henrik; Aarestrup, Frank Møller

2011-01-01

This study was conducted to determine the occurrence of zinc and copper resistances in methicillin-resistant Staphylococcus aureus (MRSA) from swine and veal calves in a global strain collection.The test population consisted of 476 porcine MRSA isolates from ten European countries, 18 porcine MRSA...... of the pig MRSA from Europe and the seven Chinese isolates belonged to other CCs and 3 isolates were not classified into a CC.All isolates were tested for susceptibility to zinc chloride and copper sulphate using agar dilution and tested by PCR for the czrC gene encoding zinc resistance.Phenotypic zinc...... resistance (MIC>2mM) was observed in 74% (n=324) and 42% (n=39) of European MRSA CC398 from pigs and veal calves, respectively, and in 44% of the Canadian isolates (n=8), but not among the Chinese isolates. Almost all (99%) zinc-resistant MRSA carried czrC. Of the 37 European non-CC398 MRSA, 62% were...

European ST80 community-associated methicillin-resistant Staphylococcus aureus orbital cellulitis in a neonate

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Tsironi Evangelia E

2012-05-01

Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus is a serious cause of morbidity and mortality in hospital environment, but also, lately, in the community. This case report is, to our knowledge, the first detailed description of a community-associated methicillin-resistant S. aureus ST80 orbital cellulitis in a previously healthy neonate. Possible predisposing factors of microbial acquisition and treatment selection are also discussed. Case presentation A 28-day-old Caucasian boy was referred to our hospital with the diagnosis of right orbital cellulitis. His symptoms included right eye proptosis, periocular edema and redness. Empirical therapy of intravenous daptomycin, rifampin and ceftriaxone was initiated. The culture of pus yielded a methicillin-resistant S. aureus isolate and the molecular analysis revealed that it was a Panton-Valentine leukocidine-positive ST80 strain. The combination antimicrobial therapy was continued for 42days and the infection was successfully controlled. Conclusions Clinicians should be aware that young infants, even without any predisposing condition, are susceptible to orbital cellulitis caused by community-associated methicillin-resistant S. aureus. Prompt initiation of the appropriate empirical therapy, according to the local epidemiology, should successfully address the infection, preventing ocular and systemic complications.

[Emergence of glycopeptide resistant Enterococcus faecium in Algeria: a case report].

Science.gov (United States)

Hamidi, Moufida; Ammari, Houria; Ghaffor, Mohamed; Benamrouche, Nabila; Tali-Maamar, Hassiba; Tala-Khir, Farida; Younsi, Mokhtar; Rahal, Kheira

2013-01-01

A glycopeptide-resistant Enterococcus faecium (EFRG) was isolated from a wound in a patient hospitalized in a university hospital in Algiers. This strain was resistant to several antibiotics. This patient was carrying this strain in the digestive tract which may partly explain its origin. Genotypic comparison of the two strains by pulsed field gel electrophoresis showed that it was the same strain. Glycopeptide resistance was due to the presence of the vanA gene. Vigilance is required facing the emergence of strains of EFRG in our hospitals.

Molecular Characterization of Methicillin-Resistant Staphylococcus aureus Causing Fatal Purulent Pericarditis.

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Kumar, Vasudevan Anil; Nair, Nisha; Thachathodiyl, Rajesh; Nandakumar, Aswathy; Dinesh, Kavitha R; Thatcher, Eileen; Karim, Shamsul; Biswas, Raja

2013-07-01

Though pericardial disease is common in patients with renal disease, purulent pericarditis is very rare. We report a fatal case of purulent pericarditis and sepsis due to methicillin-resistant Staphylococcus aureus in a 78-year-old male with systemic hypertension and renal disease along with the molecular characterization of its resistant mechanism.

Comparative Efficacy of Ceftaroline with Linezolid against Staphylococcus Aureus and Methicillin Resistant Staphylococcus Aureus

International Nuclear Information System (INIS)

Hafeez, A.; Munir, T.; Rehman, S.; Najeeb, S.; Gilani, M.; Latif, M.; Ansari, M.; Saad, N.

2015-01-01

Objective:To compare the in vitro antimicrobial efficacy of ceftaroline with linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. Study Design: Quasi-experimental study. Place and Duration of Study: Microbiology Department, Army Medical College, Rawalpindi, from January to December 2013. Methodology: Clinical samples from respiratory tract, blood, pus and various catheter tips routinely received in the Department of Microbiology, Army Medical College, Rawalpindi were innoculated on blood and MacConkey agar. Staphylococcus aureus was identified by colony morphology, Gram reaction, catalase test and coagulase test. Methicillin resistant Staphylococcus aureus detection was done by modified Kirby Bauer disc diffusion method using cefoxitin disc (30g) and the isolates were considered methicillin resistant if the zone of inhibition around cefoxitin disc was /sup 2/ 21 mm. Bacterial suspensions of 56 Staphylococcus aureus isolates and 50 MRSA isolates were prepared, which were standardized equal to 0.5 McFarland's turbidity standard and inoculated on Mueller-Hinton agar plates followed by application of ceftaroline and linezolid disc (Oxoid, UK), according to manufacturer's instructions. The plates were then incubated at 37 Degree C aerobically for 18 - 24 hours. Diameters of inhibition zone were measured and interpretated as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Out of 106 isolates all of the 56 Staphylococcus aureus (100%) were sensitive to ceftaroline and linezolid. However, out of 50 methicillin resistant Staphylococcus aureus, 48 (96%) were sensitive to ceftaroline whereas, 49 (98%) were sensitive to linezolid. Conclusion: Ceftaroline is equally effective as linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. (author)

In vitro phagocytosis of methicillin resistant and methicillin sensitive staphylococcus aureus by human polymorphonuclear leucocytes

International Nuclear Information System (INIS)

Javed, N.; Tahir, R.; Abbas, A.

2009-01-01

Staphylococcus aureus is a gram positive bacterium that causes a number of diseases such as abscesses, infective endocarditis, septic arthritis, etc. It is acquiring resistance against many antibiotics like methicillin; therefore its control is becoming increasingly difficult. Peripheral blood phagocytes particularly polymorphonuclear leucocytes play an important role in the protective mechanisms against these organisms. Phagocytes interact with bacteria and phagocytose these microorganisms to kill them. Phenotypically different isolates of Staphylococcus aureus including methicillin resistant Staphylococcus aureus (MRSA) and methicillin sensitive Staphylococcus aureus (MSSA) were collected from various hospitals of Lahore, Pakistan. Fresh polymorphonuclaer leucocytes were obtained from healthy individuals by centrifugation using Ficol-Hypaque gradient combined with dextran sedimentation. Microbiological method was used for the determination of phagocytic index of phenotypic variants of Staphylococcus aureus. A significant difference was observed between the phagocytic index of both bacterial groups. MSSA group showed the Mean+-SD of 79.46%+-3.9 while MRSA group showed 72.35%+-2.5. Significant difference in phagocytic index indicates that it can be one of the mechanisms of MRSA to evade host immune system as compare to MSSA. (author)

Impacto de la resistencia a la meticilina sobre la mortalidad y vigilancia de la sensibilidad a la vancomicina en bacteriemias causadas por Staphylococcus aureus Impact of methicillin resistance on mortality and surveillance of vancomycin susceptibility in bacteremias caused by Staphylococcus aureus

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F. Traverso

2010-12-01

Full Text Available Staphylococcus aureus es uno de los principales patógenos nosocomiales y produce una alta morbimortalidad en numerosos hospitales del mundo. Además, la incidencia de bacteriemias por este microorganismo ha aumentado significativamente en las últimas décadas. Los objetivos del presente trabajo fueron identificar los factores de riesgo que favorecen la aparición de resistencia a la meticilina en aislamientos de S. aureus y los factores que afectan la mortalidad por bacteriemias asociadas a este patógeno, así como evaluar la sensibilidad a la vancomicina de las cepas resistentes a la meticilina. Se estudiaron 39 aislamientos de S. aureus provenientes de hemocultivos de pacientes internados con bacteriemia en la Nueva Clínica Chacabuco de Tandil (Pcia. de Buenos Aires, Argentina en el período 01/2006-12/2008. La mortalidad global fue del 51,3% y estuvo significativamente asociada con la resistencia a la meticilina (OR: 4,20; IC95%: 1,08-16,32; p: 0,05; aunque dicho factor no fue un predictor independiente de mortalidad. La cirugía previa (OR: 17,23; IC95%: 1,80-164,60 y la estancia previa en la unidad de cuidados intensivos (OR: 21,12; IC95%: 2,33-191,30 fueron predictores independientes de la resistencia a la meticilina y la asistencia respiratoria mecánica (OR: 15,99; IC: 3,24-78,86 fue un predictor independiente de la mortalidad. No se detectaron cepas con sensibilidad disminuida a la vancomicina. Todos los aislamientos estudiados fueron sensibles in vitro a la vancomicina, con una CIM50 y una CIM90 de 0,5 μg/ml.Staphylococcus aureus is a major nosocomial pathogen that causes severe morbidity and mortality in many hospitals worldwide. Besides, the incidence of S. aureus bacteremia has significantly increased over the past decades. The aims of this study were to detect the risk factors for methicillin resistance and mortality and to evaluate vancomycin susceptibility in methicillin-resistant isolates. Thus, 39 S. aureus isolates from

Occurrence and characterization of livestock-associated methicillin-resistant Staphylococcus aureus in pig industries of northern Thailand.

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Patchanee, Prapas; Tadee, Pakpoom; Arjkumpa, Orapun; Love, David; Chanachai, Karoon; Alter, Thomas; Hinjoy, Soawapak; Tharavichitkul, Prasit

2014-12-01

This study was conducted to determine the prevalence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in pigs, farm workers, and the environment in northern Thailand, and to assess LA-MRSA isolate phenotypic characteristics. One hundred and four pig farms were randomly selected from the 21,152 in Chiang Mai and Lamphun provinces in 2012. Nasal and skin swab samples were collected from pigs and farm workers. Environmental swabs (pig stable floor, faucet, and feeder) were also collected. MRSA was identified by conventional bacterial culture technique, with results confirmed by multiplex PCR and multi locus sequence typing (MLST). Herd prevalence of MRSA was 9.61% (10 of 104 farms). Among pigs, workers, and farm environments, prevalence was 0.68% (two of 292 samples), 2.53% (seven of 276 samples), and 1.28% (four of 312 samples), respectively. Thirteen MRSA isolates (seven from workers, four from environmental samples, and two from pigs) were identified as Staphylococcal chromosomal cassette mec IV sequences type 9. Antimicrobial sensitivity tests found 100% of the MRSA isolates resistant to clindamycin, oxytetracycline, and tetracycline, while 100% were susceptible to cloxacillin and vancomycin. All possessed a multidrug-resistant phenotype. This is the first evidence of an LA-MRSA interrelationship among pigs, workers, and the farm environment in Thailand.

Characterization of methicillin-resistant Staphylococcus aureus isolates from pig carcasses in Hong Kong

DEFF Research Database (Denmark)

Ho, J.; O'Donoghue, M.; Guardabassi, Luca

2012-01-01

This study describes the isolation and characterization of methicillin-resistant Staphylococcus aureus (MRSA) from slaughtered pigs sampled from local markets in Hong Kong. The nares of 400 slaughtered pigs were cultured and MRSA isolates characterized for the presence of antibiotic-resistance de......This study describes the isolation and characterization of methicillin-resistant Staphylococcus aureus (MRSA) from slaughtered pigs sampled from local markets in Hong Kong. The nares of 400 slaughtered pigs were cultured and MRSA isolates characterized for the presence of antibiotic...... tet(M). Resistance to erythromycin (89%) and chloramphenicol (71%) was associated with the presence of erm(C), and fex(A), respectively. No strains carried cfr and there was no resistance to linezolid, although minimum inhibitory concentration (MICs) were close to the resistance break point...

Distribution and characterization of methicillin-resistant Staphylococcus aureus (MRSA) at the small animal hospital, faculty of veterinary medicine, Chiang Mai University, Thailand.

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Patchanee, Prapas; Tadee, Pakpoom; Ingkaninan, Pimlada; Tankaew, Pallop; Hoet, Armando E; Chupia, Vena

2014-03-01

Of 416 samples taken from veterinary staff (n = 30), dogs (n = 356) and various environmental sites (n = 30) at the Small Animal Hospital, Faculty of Veterinary Medicine, Chiang Mai University, Thailand, 13 samples contained methicillin-resistant Staphylococcus aureus (MRSA), of which 1 (SCCmec type II) came from veterinarian, 9 (SCCmec types I, III, IVa, V and untypeable) from dogs, and 3 (SCCmec types I, III, and IVb) from environmental samples. The MRSA isolates were 100% susceptible to vancomycin (100%), 69% to cephazolin and 62% to gentamicin, but were up to 92% resistant to tetracycline group, 69% to trimethoprim-sulfamethoxazoles and 62% to ceftriaxone. In addition, all MRSA isolates showed multidrug resistance. As the MRSA isolates from the veterinary staff and dogs were of different SCCmec types, this suggests there were no cross-infections. However, environmental contamination appears to have come from dogs, and appropriate hygienic practices should be introduced to solve this problem.

Nurses' experience with vancomycin-resistant enterococci (VRE).

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Mitchell, Ann; Cummins, Teresa; Spearing, Natalie; Adams, June; Gilroy, Lisa

2002-01-01

The emergence and spread of resistant organisms, in particular vancomycin-resistant enterococci (VRE), is an issue facing all staff in acute hospitals. This study explored how nurses coped with the responsibility of halting further spread of this organism during an outbreak. VRE-positive patients were cohorted with nurses who cared for them in an endeavour to contain the spread of VRE. The majority of nurses found the situation extremely stressful because of the need to act as 'gatekeepers' responsible for educating and monitoring the practices of staff and visitors. The nurses reported that they felt they were inadequately supported, were blamed for the outbreak, and that they had an increased workload as they took on duties of other staff. The results reinforce the need for a multidisciplinary team approach to education and control of VRE, more support for nursing staff cohorted with VRE-positive patients, and stringent adherence to infection control measures by all hospital staff.

Methicillin resistant Staphylococcus aureus nasal colonization among secondary school students at Duhok City-Iraq

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Ary Habeeb

2014-06-01

Full Text Available Objective:Methicillin-resistant Staphylococcus aureus (MRSA widely distributed in hospitals around the world. There is strong relationship between disease development and S. aureus nasal carriage. The aim of this study was to evaluate the prevalence and epidemiology of nasal colonization with S. aureus and MRSA in the community of Duhok city, Iraq. Methods: 489 students aged 16 to18 years were included. Nasal swab samples were collected followed by antimicrobial susceptibility test. MRSA isolates were selected and investigated for the mecA gene. Also the prevalence of PantonValentine Leukocidin (PVL gene was also studied. Results: A total of 90 (18.4% out of 489 (18.4% of the students were found to be colonized by S. aureus . Only 10 (2.04% of the students were found to be MRSA carrier. All MRSA isolates were sensitive to Vancomycin. PLV gene was detected in one MRSA strain. Conclusion: This is the first study investigating S. aureus colonization in students in the Duhok city. Nasal carriage of S. aureus and MRSA is comparable with reports from elsewhere. Fortunately, all trains included in our study were sensitive to vancomycin. Further research is needed to examine the SCCmec elements and the evolution of MRSA over the time. J Microbiol Infect Dis 2014;4(2: 59-63

Prevalence of Methicillin Resistant Staphylococcus aureus in pyogenic community and hospital acquired skin and soft tissues infections

International Nuclear Information System (INIS)

Ahmad, M. K.; Asrar, A.

2014-01-01

Objective: To determine the percentage and frequency of Methicillin Resistant Staphylococcus aureus in community and hospital-acquired pyogenic skin and soft tissue infections. Methods: The descriptive cross-sectional study was conducted at the Dermatology Department of Combined Military Hospital, Abbottabad, from June 2009 to March 2010, and comprised 144 community-acquired and 54 hospital-acquired skin and soft tissue infections. Pus swabs from the infected lesions one from each individual were sent to laboratory for culture and sensitivity tests. Methicillin resistance was detected by 1 (mu) g oxacillin disk. Organisms were labelled methicillin-resistant once the inhibition zone for oxocillin was less than 10 mm. Data analysis was done by using SPSS 20. Results: Of the 198 patients in the study, 98(49.5%) were males and 100(50.5%) were females, with an overall mean age of 33.7+-14.8144 years. There were 144(72.72%) community-acquired infections and 54(27.27%) had hospital-acquired infections. Community-acquired Methicillin Resistant Staphylococcus aureus numbered 40(27.8%) and hospital-acquired ones numbered 26(48.1%). Conclusion: Prevalence of Methicillin Resistant Staphylococcus aureus in community and hospital-acquired pyogenic skin and soft tissue infections was high. (author)

Comparison of antibiotic resistance, virulence gene profiles, and pathogenicity of methicillin-resistant and methicillin-susceptible Staphylococcus aureus using a Caenorhabditis elegans infection model

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Thompson, Terissa; Brown, Paul D

2014-01-01

Objectives: This study compared the presence of 35 virulence genes, resistance phenotypes to 11 anti-staphylococcal antibiotics, and pathogenicity in methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA). Methods: Multiplex PCR analysis was used to differentiate Staphylococcus aureus isolates (n = 102) based on characterization of the Staphylococcal Cassette Chromosome mec (SCCmec). Singleplex and multiplex PCR assays targeting 35 virulence determinants were used to analyze the virulence repertoire of S. aureus. In vitro activities of the antibiotics were determined by the disk-diffusion method. The pathogenicity of representative isolates was assessed using Caenorhabditis elegans survival assays. Significance in virulence distribution and antibiotic resistance phenotypes was assessed using the Chi-squared tests. Kaplan–Meier survival estimates were used to analyze nematode survival and significance of survival rates evaluated using the log-rank test. Results: Except for sei (staphylococcal enterotoxin I) (P  =  0.027), all other virulence genes were not significantly associated with MRSA. Resistance to clindamycin (P  =  0.03), tetracycline (P  =  0.048), trimethoprim/sulfamethoxazole (P  =  0.038), and oxacillin (P  =  0.004) was significantly associated with MRSA. Survival assay showed MSSA having a lower median lifespan of 3 days than MRSA that had a median lifespan of 6 days. The difference in the killing time of MRSA and MSSA was significant (P virulence genes. The quicker killing potential of MSSA compared to MRSA suggests that carriage of virulence determinants per se does not determine pathogenicity in S. aureus. Pathogenicity is impacted by other factors, possibly antibiotic resistance. PMID:25319852

Activity of linezolid and tedizolid against clinical isolates of methicillin-resistant and methicillin and linezolid resistant Staphylococcus aureus: an in vitro comparison.

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Peñuelas, M; Candel, F J; Lejarraga, C; López-González, L; Viñuela-Prieto, J M; López de Mendoza, D

2016-10-01

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in Spain is approximately 20-30%. However, resistance to linezolid is rare, and the main reports are from nosocomial outbreaks. The objective of the present study was to compare the in vitro susceptibility of linezolid with that of tedizolid against MRSA isolates and methicillin-and linezolid-resistant isolates (MLRSA) mediated by the cfr gene. The in vitro susceptibility of linezolid and tedizolid was determined using the E-test with 18 MRSA strains and 18 cfr-mediated MLRSA strains obtained from clinical isolates in the microbiology service of a tertiary university hospital. All MRSA strains were susceptible to both antibiotics. Analysis of the MRSA isolates revealed that the MIC50 and MIC90 of linezolid were 1.5 and 2 mg/L, respectively; those of tedizolid were 0.25 and 0.4 mg/L. The MIC50 and MIC90 of tedizolid remained at 0.75 and 1 mg/L against the MLRSA strains (MIC90 ≥ 8 mg/L). Both for MRSA and for MLRSA, the MICs obtained for tedizolid were at least 2 dilutions lower than those of linezolid, thus demonstrating between 2 and 4 times greater activity in vitro than linezolid.

Transmission of methicillin-resistant Staphylococcus aureus to household contacts

NARCIS (Netherlands)

F.P.N. Mollema (Femke); J.H. Richardus (Jan Hendrik); M.D. Behrendt (Myra); N. Vaessen (Norbert); W. Lodder; W. Hendriks; H.A. Verbrugh (Henri); A. Voss (Andreas)

2010-01-01

textabstractThe frequency of and risk factors for methicillin-resistant Staphylococcus aureus (MRSA) transmission from a MRSA index person to household contacts were assessed in this prospective study. Between January 2005 and December 2007, 62 newly diagnosed MRSA index persons (46 patients and 16

Effectiveness of simple control measures on methicillin-resistant Staphylococcus aureus infection status and characteristics with susceptibility patterns in a teaching hospital in Peshawar.

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Rafiq, Muhammad Salman; Rafiq, Muhammad Imran; Khan, Taimur; Rafiq, Maria; Khan, Mah Muneer

2015-09-01

To determine the effectiveness of simple control measures on the infection status and characteristics of methicillin-resistant Staphylococcus aureus including susceptibility patterns among health professionals and patients in a teaching hospital. The cross-sectional study was conducted from September 2013 to January 2014, and comprised samples collected from healthcare personnel and patients in the various units of Khyber Teaching Hospital, Peshawar. The specimens were collected before and one month after the implementation of simple control measures for outbreak prevention of methicillin-resistant Staphylococcus aureus. These were tested for culture and antimicrobial susceptibility. Data about methicillin-sensitive and methicillin-resistant Staphylococcus aureus infection, wound characteristics and susceptibility patterns was collected and effectiveness of simple control measures was determined. SPSS 20 was used for statistical analysis. Of the total 390 isolates, 180(46.2%) were Staphylococcus aureus; 77(19.7%) from healthcare personnel and 103(26.4%) from patients. Of these, 164(42.1%) were methicillin-sensitive and 16(4.1%) were methicillin-resistant. Among the patients, 38(15.1%) methicillin-sensitive and 8(3.2%) methicillin-resistant isolates were recovered from wounds or skin and soft tissues. Pus with 33(13.1%) and 4(1.6%) cases respectively was the second most common source. Among methicillin-resistant isolates, resistance to Linezolid was 0%, all were resistant to Oxacillin, Cefoxitin, Amoxicillin, Cefotaxime and Cephradine, and resistance to both Co-Amoxiclav and Ciprofloxacin was 87.5%. After one month of implementation of simple control measures, the number of methicillin-resistant cases among healthcare professionals and patients dropped from 4(2.9%) and 7(10.8%) to 1(0.7%) and 5(2.7%), respectively. Methicillin-resistant and methicillin-sensitive Staphylococcus aureus differed in their anti-microbial susceptibility profiles. Selection of antibiotics

The changing face of community-acquired methicillin-resistant Staphylococcus aureus

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P Kale

2016-01-01

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA is an important cause of infection, both in hospitalised patients with significant healthcare exposure and in patients without healthcare risk factors. Community-acquired methicillin-resistant S. aureus (CA-MRSA are known for their rapid community transmission and propensity to cause aggressive skin and soft tissue infections and community-acquired pneumonia. The distinction between the healthcare-associated (HA-MRSA and CA-MRSA is gradually fading owing to the acquisition of multiple virulence factors and genetic elements. The movement of CA-MRSA strains into the nosocomial setting limits the utility of using clinical risk factors alone to designate community or HA status. Identification of unique genetic characteristics and genotyping are valuable tools for MRSA epidemiological studies. Although the optimum pharmacotherapy for CA-MRSA infections has not been determined, many CA-MRSA strains remain broadly susceptible to several non-β-lactam antibacterial agents. This review aimed at illuminating the characteristic features of CA-MRSA, virulence factors, changing clinical settings and molecular epidemiology, insurgence into the hospital settings and therapy with drug resistance.

Sensitivity of antibiotic resistant and antibiotic susceptible Escherichia coli, Enterococcus and Staphylococcus strains against ozone.

Science.gov (United States)

Heß, Stefanie; Gallert, Claudia

2015-12-01

Tolerance of antibiotic susceptible and antibiotic resistant Escherichia coli, Enterococcus and Staphylococcus strains from clinical and wastewater samples against ozone was tested to investigate if ozone, a strong oxidant applied for advanced wastewater treatment, will affect the release of antibiotic resistant bacteria into the aquatic environment. For this purpose, the resistance pattern against antibiotics of the mentioned isolates and their survival after exposure to 4 mg/L ozone was determined. Antibiotic resistance (AR) of the isolates was not correlating with higher tolerance against ozone. Except for ampicillin resistant E. coli strains, which showed a trend towards increased resistance, E. coli strains that were also resistant against cotrimoxazol, ciprofloxacin or a combination of the three antibiotics were similarly or less resistant against ozone than antibiotic sensitive strains. Pigment-producing Enterococcus casseliflavus and Staphylococcus aureus seemed to be more resistant against ozone than non-pigmented species of these genera. Furthermore, aggregation or biofilm formation apparently protected bacteria in subsurface layers from inactivation by ozone. The relatively large variance of tolerance against ozone may indicate that resistance to ozone inactivation most probably depends on several factors, where AR, if at all, does not play a major role.

Contamination of the Clinical Microbiology Laboratory with Vancomycin-Resistant Enterococci and Multidrug- Resistant Enterobacteriaceae: Implications for Hospital and Laboratory Workers

Science.gov (United States)

Collins, Susan M.; Hacek, Donna M.; Degen, Lisa A.; Wright, Marc O.; Noskin, Gary A.; Peterson, Lance R.

2001-01-01

We surveyed environmental surfaces in our clinical microbiology laboratory to determine the prevalence of vancomycin-resistant enterococci (VRE) and multidrug-resistant Enterobacteriaceae (MDRE) during a routine working day. From a total of 193 surfaces, VRE were present on 20 (10%) and MDRE were present on 4 (2%) of the surfaces tested. In a subsequent survey after routine cleaning, all of the 24 prior positive surfaces were found to be negative. Thus, those in the laboratory should recognize that many surfaces may be contaminated by resistant organisms during routine processing of patient specimens. PMID:11574615

Antimicrobial activity of zinc and titanium dioxide nanoparticles against biofilm-producing methicillin-resistant Staphylococcus aureus

Science.gov (United States)

Jesline, A.; John, Neetu P.; Narayanan, P. M.; Vani, C.; Murugan, Sevanan

2015-02-01

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major nosocomial pathogens responsible for a wide spectrum of infections and the emergence of bacterial resistance to antibiotics has lead to treatment drawbacks towards large number of drugs. Formation of biofilms is the main contributing factor to antibiotic resistance. The development of reliable processes for the synthesis of zinc oxide nanoparticles is an important aspect of nanotechnology today. Zinc oxide and titanium dioxide nanoparticles comprise well-known inhibitory and bactericidal effects. Emergence of antimicrobial resistance by pathogenic bacteria is a major health problem in recent years. This study was designed to determine the efficacy of zinc and titanium dioxide nanoparticles against biofilm producing methicillin-resistant S. aureus. Biofilm production was detected by tissue culture plate method. Out of 30 MRSA isolates, 22 isolates showed strong biofilm production and 2 showed weak and moderate biofilm formation. Two strong and weak biofilm-producing methicillin-resistant S. aureus isolates were subjected to antimicrobial activity using commercially available zinc and titanium dioxide nanoparticles. Thus, the nanoparticles showed considerably good activity against the isolates, and it can be concluded that they may act as promising, antibacterial agents in the coming years.

Antimicrobial resistance and virulence genes in enterococci from wild game meat in Spain.

Science.gov (United States)

Guerrero-Ramos, Emilia; Cordero, Jorge; Molina-González, Diana; Poeta, Patrícia; Igrejas, Gilberto; Alonso-Calleja, Carlos; Capita, Rosa

2016-02-01

A total of 55 enterococci (45 Enterococcus faecium, 7 Enterococcus faecalis, and three Enterococcus durans) isolated from the meat of wild game animals (roe deer, boar, rabbit, pheasant, and pigeon) in North-Western Spain were tested for susceptibility to 14 antimicrobials by the disc diffusion method. All strains showed a multi-resistant phenotype (resistance to between three and 10 antimicrobials). The strains exhibited high percentages of resistance to erythromycin (89.1%), tetracycline (67.3%), ciprofloxacin (92.7%), nitrofurantoin (67.3%), and quinupristin-dalfopristin (81.8%). The lowest values (9.1%) were observed for high-level resistance to gentamicin, kanamycin, and streptomycin. The average number of resistances per strain was 5.8 for E. faecium isolates, 7.9 for E. faecalis, and 5.7 for E. durans. Genes encoding antimicrobial resistance and virulence were studied by polymerase chain reaction. A total of 15 (57.7%) of the 26 vancomycin-resistant isolates harboured the vanA gene. Other resistance genes detected included vanB, erm(B) and/or erm(C), tet(L) and/or tet(M), acc(6')-aph(2″), and aph(3')-IIIa in strains resistant to vancomycin, erythromycin, tetracycline, gentamicin, and kanamycin, respectively. Specific genes of the Tn5397 transposon were detected in 54.8% of the tet(M)-positive enterococci. Nine virulence factors (gelE, agg, ace, cpd, frs, esp, hyl, efaAfs and efaAfm) were studied. All virulence genes, with the exception of the frs gene, were found to be present in the enterococcal isolates. At least one virulence gene was detected in 20.0% of E. faecium, 71.4% of E. faecalis and 33.3% of E. durans isolates, with ace and cpd being the most frequently detected genes (6 isolates each). This suggests that wild game meat might play a role in the spreading through the food chain of enterococci with antimicrobial resistance and virulence determinants to humans. Copyright © 2015 Elsevier Ltd. All rights reserved.

Methicillin resistance in Staphylococcus aureus : a review of the ...

African Journals Online (AJOL)

Methicillin resistance in Staphylococcus aureus : a review of the molecular epidemiology, clinical significance and laboratory detection methods. ... Added to this burden is the emergence of more virulent strains of community-associated MRSA (CAMRSA) which at the turn of the century, has been increasingly reported to ...

Comparative genomics of community-acquired ST59 methicillin-resistant Staphylococcus aureus in Taiwan: novel mobile resistance structures with IS1216V.

Directory of Open Access Journals (Sweden)

Wei-Chun Hung

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA with ST59/SCCmecV and Panton-Valentine leukocidin gene is a major community-acquired MRSA (CA-MRSA lineage in Taiwan and has been multidrug-resistant since its initial isolation. In this study, we studied the acquisition mechanism of multidrug resistance in an ST59 CA-MRSA strain (PM1 by comparative genomics. PM1's non-β-lactam resistance was encoded by two unique genetic traits. One was a 21,832-bp composite mobile element structure (MES(PM1, which was flanked by direct repeats of enterococcal IS1216V and was inserted into the chromosomal sasK gene; the target sequence (att was 8 bp long and was duplicated at both ends of MES(PM1. MES(PM1 consisted of two regions: the 5'-end side 12.4-kb region carrying Tn551 (with ermB and Tn5405-like (with aph[3']-IIIa and aadE, similar to an Enterococcus faecalis plasmid, and the 3'-end side 6,587-bp region (MES(cat that carries cat and is flanked by inverted repeats of IS1216V. MES(cat possessed att duplication at both ends and additional two copies of IS1216V inside. MES(PM1 represents the first enterococcal IS1216V-mediated composite transposon emerged in MRSA. IS1216V-mediated deletion likely occurred in IS1216V-rich MES(PM1, resulting in distinct resistance patterns in PM1-derivative strains. Another structure was a 6,025-bp tet-carrying element (MES(tet on a 25,961-bp novel mosaic penicillinase plasmid (pPM1; MES(tet was flanked by direct repeats of IS431, but with no target sequence repeats. Moreover, the PM1 genome was deficient in a copy of the restriction and modification genes (hsdM and hsdS, which might have contributed to the acquisition of enterococcal multidrug resistance.

[Prevalence and predisposing factors of methicillin-resistant Staphylococcus aureus in long-term care facilities. An international view].

Science.gov (United States)

Szabó, Rita

2016-07-03

Methicillin-resistant Staphylococcus aureus is one of the most important pathogens of healthcare and long-term care-associated infections over the world, resulting high morbidity, mortality and extra costs in these settings. The authors analyze the prevalence and predisposing factors of methicillin-resistant Staphylococcus aureus in long-term care facilities. Systematic review using PubMed, ScienceDirect and Cochrane Library CENTRAL databases between January 1, 2006 and December 31, 2015 was performed. In the past ten years methicillin-resistant Staphylococcus aureus prevalence in European long-term care facilities (12.6%) was lower than in North America (33.9%). The most frequent predisposing factor was previous antimicrobial therapy, hospital admission and infection/colonisation, chronic wounds, and high care need. Based on the results, the prevention and control of methicillin-resistant Staphylococcus aureus is an important public health priority in the European and Hungarian long-term care facilities.

Improved outcome of ventilator-associated pneumonia caused by methicillin-resistant Staphylococcus aureus in a trauma population.

Science.gov (United States)

Gonzalez, Richard P; Rostas, Jack; Simmons, Jon D; Allen, John; Frotan, Mohammad A; Brevard, Sidney B

2013-03-01

The treatment of ventilator-associated pneumonia (VAP) secondary to methicillin-resistant Staphylococcus aureus (MRSA) remains controversial. We performed a review of all blunt trauma patients diagnosed with MRSA VAP from June 2005 to June 2011. VAP for the first 3 years was diagnosed by sputum aspiration and treated with vancomycin. For the last 3 years of the study period, VAP was diagnosed with bronchoalveolar lavage and treated with linezolid. MRSA VAP patients treated with vancomycin had an average hospital length of stay (LOS) of 49 days (range 9-99 days), an average intensive care unit (ICU) LOS of 43 days (range 6-98 days), and average ventilator days of 34.4 (range 3-76 days). Seventeen MRSA VAP patients treated with linezolid had an average hospital LOS of 27 days (range 11-61), an average ICU LOS of 22 days (range 10-42) days, and average ventilator days of 16.6 (range 2-42). Trauma patients who develop MRSA VAP appear to have fewer ventilator days and shorter ICU and hospital LOS when treated with linezolid. Copyright © 2013 Elsevier Inc. All rights reserved.

Comparative antibacterial activity of topical antiseptic eardrops against methicillin-resistant Staphylococcus aureus and quinolone-resistant Pseudomonas aeruginosa.

Science.gov (United States)

Youn, Cha Kyung; Jang, Sook-Jin; Jo, Eu-Ri; Choi, Ji Ae; Sim, Ju-Hwan; Cho, Sung Il

2016-06-01

Aural irrigation using antiseptic solutions can be an effective medical treatment of chronic suppurative otitis media (CSOM) owing to the increasing prevalence of antibiotic-resistant CSOM infections. In the present study, we compared the antimicrobial activities of 100% Burow's solution, 50% Burow's solution, 2% acetic acid, vinegar with water (1:1), and 4% boric acid solution against methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible S. aureus (MSSA), quinolone-resistant Pseudomonas aeruginosa (QRPA), and quinolone-susceptible P. aeruginosa (QSPA) in vitro. We examined the antimicrobial activities of five antiseptic solutions against MRSA, MSSA, QRPA, and QSPA. The antimicrobial activities of the solutions were calculated as a percentage of the surviving microorganisms by dividing the viable count in each antiseptic solution with that in control. The time (D10 value) required for each of the five solutions to inactivate 90% of the microorganism population was also investigated. Burow's solution exhibited the highest antimicrobial activity and the lowest D10 value against MRSA, MSSA, QRPA, and QSPA, followed by 2% acetic acid, vinegar with water (1:1), and 4% boric acid solution. Our results indicate that Burow's solution has the most potent activity against bacteria including antibiotic-resistant strains. Twofold dilution of the solution is recommended to avoid ototoxicity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Fitness and competitive growth comparison of methicillin resistant and methicillin susceptible Staphylococcus aureus colonies.

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Durhan, Emine; Korcan, Safiye Elif; Altindis, Mustafa; Konuk, Muhsin

2017-05-01

Exponential developments of both Methicillin resistant Staphylococcus aureus (MRSA) 3R ve 36R and methicillin susceptible Staphylococcus aureus (MSSA) 27S were evaluated in the presence and absence of oxacillin. The strains were isolated from the specimens collected in microbiology department. It was also determined the transfer of mecA gene from 3R to 27S strain by using the replica plate technique. It was observed that the presence of antibiotics in the preliminary culture had a positive impact on the growth of the secondary culture of MRSA isolates. Comparison results of Rt bacteria in three different mixed cultures, assessed with Tukey's HSD test, showed a significant statistical difference among the groups. The values were as following; on the first day; Df: 2, F: 60.90, P: 0.0001, second day; Df:2, F:90.56, P: 0.0000, and third day; Df:2, F:4.86, P:0.0557. As a result of the study, we can suggest that the gene expression levels of the transferred antibiotic resistance genes could help us in both controlling hospital originated sickness and developing new strategies to prevent the spread of resistant bacteria. Copyright © 2016 Elsevier Ltd. All rights reserved.

Graphene oxide-silver nanocomposite as a promising biocidal agent against methicillin-resistant Staphylococcus aureus

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de Moraes ACM

2015-11-01

Full Text Available Ana Carolina Mazarin de Moraes,1 Bruna Araujo Lima,2 Andreia Fonseca de Faria,1 Marcelo Brocchi,2 Oswaldo Luiz Alves1 1Laboratory of Solid State Chemistry, Institute of Chemistry, University of Campinas, Campinas, São Paulo, Brazil; 2Department of Genetics, Evolution and Bioagents, Institute of Biology, University of Campinas, Campinas, São Paulo, Brazil Background: Methicillin-resistant Staphylococcus aureus (MRSA has been responsible for serious hospital infections worldwide. Nanomaterials are an alternative to conventional antibiotic compounds, because bacteria are unlikely to develop microbial resistance against nanomaterials. In the past decade, graphene oxide (GO has emerged as a material that is often used to support and stabilize silver nanoparticles (AgNPs for the preparation of novel antibacterial nanocomposites. In this work, we report the synthesis of the graphene-oxide silver nanocomposite (GO-Ag and its antibacterial activity against relevant microorganisms in medicine. Materials and methods: GO-Ag nanocomposite was synthesized through the reduction of silver ions (Ag+ by sodium citrate in an aqueous GO dispersion, and was extensively characterized using ultraviolet-visible absorption spectroscopy, X-ray diffraction, thermogravimetric analysis, X-ray photoelectron spectroscopy, and transmission electron microscopy. The antibacterial activity was evaluated by microdilution assays and time-kill experiments. The morphology of bacterial cells treated with GO-Ag was investigated via transmission electron microscopy. Results: AgNPs were well distributed throughout GO sheets, with an average size of 9.4±2.8 nm. The GO-Ag nanocomposite exhibited an excellent antibacterial activity against methicillin-resistant S. aureus, Acinetobacter baumannii, Enterococcus faecalis, and Escherichia coli. All (100% MRSA cells were inactivated after 4 hours of exposure to GO-Ag sheets. In addition, no toxicity was found for either pristine GO or bare Ag

Molecular epidemiology of Enterococcus faecium: from commensal to hospital adapted pathogen

NARCIS (Netherlands)

Top, J.

2007-01-01

For many years Enterococcus faecium was considered a commensal of the digestive tract, which only sporadically caused opportunistic infections in severely ill patients. Over the last two decades, vancomycin resistant E. faecium (VREF) has emerged worldwide as an important cause of nosocomial

Antimicrobial blue light inactivation of Methicillin-resistant Staphylococcus aureus

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Wang, Yucheng; Dai, Tianhong; Gu, Ying

2016-10-01

Background: With the increasing emergence of multidrug-resistant (MDR) bacterial strains, there is a pressing need for the development of alternative treatment for infections. Antimicrobial blue light (aBL) has provided a simple and effective approach. Methods: We first investigated the effectiveness of aBL (415 nm) inactivation of USA300 LAClux (a communityacquired Methicillin-resistant Staphylococcus aureus strain) both in the planktonic and biofilm forms. The survival of the bacteria in suspensions was determined by serial dilution and that of the biofilm-embedded bacteria was determined by bioluminescence quantification. Using a mouse model of thermal burn infected with USA300 LAClux, we further assessed the effectiveness of aBL for treating localized infections. Bioluminescence imaging was performed to monitor in real time bacterial viability in vivo. Results: In vitro study showed that, for the planktonic counterpart of the bacteria or the 24-h-old biofilms, an irradiance of 55 mW/cm2 for 60 min resulted in a 4.61 log10 or 2.56 log10 inactivation, respectively. In vivo study using infected mouse burns demonstrated that a 2.56-log10 inactivation was achieved after 100-mW/cm2 irradiation for 62 min. Conclusions: aBL is a potential alternative approach for treating Methicillin-resistant Staphylococcus aureus infections.

Global transcriptional response of methicillin-resistant Staphylococcus aureus to thioridazine

DEFF Research Database (Denmark)

Bonde, Mette; Jacobsen, Kirstine; Kolmos, Hans Jørn

Few drugs are available against methicillin-resistant S. aureus (MRSA), and decreased susceptibility among staphylococci to newly introduced agents such as linezolid, daptomycin, and tigecycline has been observed [1-3]. Consequently, new treatment strategies are urgently needed. Thioridazine...

Antibiotics for methicillin-resistant Staphylococcus aureus skin and soft tissue infections: the challenge of outpatient therapy.

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Pate, Amy J; Terribilini, Reno Giovonni; Ghobadi, Farzaneh; Azhir, Alaleh; Barber, Andre; Pearson, Julie Marie; Kalantari, Hossein; Hassen, Getaw W

2014-02-01

Methicillin-resistant Staphylococcus aureus (MRSA) infections are becoming increasingly prevalent in both community and hospital settings. Certain strains are notorious for causing skin and soft tissue infections in patients with no established risk factors. In this article, we report our findings on the dynamic antibiotic resistance pattern of MRSA and outpatient prescription trend for skin and soft tissue infections within our community. We conducted a retrospective medical record review of 1876 patients evaluated in the emergency department of an urban community hospital from 2003 to 2012. Data regarding culture isolates and associated antimicrobial resistance, antibiotic treatment, site of specimen collection, age, race, and sex were collected and analyzed. Analysis of 1879 culture specimens yielded 2193 isolates. In some cases, a single specimen yielded polymicrobial growth. Staphylococcus aureus represented 996 isolates (45.4%); 463 were methicillin-susceptible (21.1%) and 533 (24.3%) were methicillin-resistant. Most patients were prescribed a single- or poly-drug regimen of trimethoprim/sulfamethoxazole, cephalexin, and clindamycin. Antimicrobial resistance analysis indicated that MRSA became increasingly resistant to the aforementioned antibiotics over time: 10% and 6% in 2012 vs 3.5% and 3.4% in 2007 for clindamycin and trimethoprim/sulfamethoxazole, respectively. Methicillin-resistant Staphylococcus aureus is a particularly virulent, rapidly adaptive pathogen that is becoming increasingly difficult to combat with existing antibiotics. Care must be taken to ensure appropriate treatment and follow-up of patients with known MRSA infections. © 2013.

High Rate of Resistance to Quinupristin-Dalfopristin in Enterococcus faecium Clinical Isolates from Korea

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Oh, Won Sup; Ko, Kwan Soo; Song, Jae-Hoon; Lee, Mi Young; Park, Sulhee; Peck, Kyong Ran; Lee, Nam Yong; Kim, Choon-Kwan; Lee, Hyuck; Kim, Shin-Woo; Chang, Hyun-Ha; Kim, Yeon-Sook; Jung, Sook-In; Son, Jun Seong; Yeom, Joon-Sup; Ki, Hyun Kyun; Woo, Gun-Jo

2005-01-01

We tested the in vitro susceptibilities of 603 enterococcal isolates from eight tertiary-care hospitals in Korea. The quinupristin-dalfopristin resistance rate in Enterococcus faecium was very high (25 isolates, 10.0%). It was suggested that both clonal spread and the sporadic emergence of quinupristin-dalfopristin-resistant isolates may explain the high prevalence of quinupristin-dalfopristin resistance in Korea. PMID:16304198

Bacterial contamination of computer touch screens.

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Gerba, Charles P; Wuollet, Adam L; Raisanen, Peter; Lopez, Gerardo U

2016-03-01

The goal of this study was to determine the occurrence of opportunistic bacterial pathogens on the surfaces of computer touch screens used in hospitals and grocery stores. Opportunistic pathogenic bacteria were isolated on touch screens in hospitals; Clostridium difficile and vancomycin-resistant Enterococcus and in grocery stores; methicillin-resistant Staphylococcus aureus. Enteric bacteria were more common on grocery store touch screens than on hospital computer touch screens. Published by Elsevier Inc.

Lipoteichoic acid synthesis inhibition in combination with antibiotics abrogates growth of multidrug-resistant Enterococcus faecium

NARCIS (Netherlands)

Paganelli, Fernanda L.; van de Kamer, Tim; Brouwer, Ellen C.; Leavis, Helen L.; Woodford, Neil; Bonten, Marc J M; Willems, Rob J L; Hendrickx, Antoni P A

Enterococcus faecium is a multidrug-resistant (MDR) nosocomial pathogen causing significant morbidity in debilitated patients. New antimicrobials are needed to treat antibiotic-resistant E. faecium infections in hospitalised patients. E. faecium incorporates lipoteichoic acid (LTA)

High frequency of methicillin-susceptible and methicillin-resistant Staphylococcus aureus in children under 1 year old with skin and soft tissue infections.

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Salazar-Ospina, Lorena; Jiménez, Judy Natalia

2017-09-21

Staphylococcus aureus is responsible for a large number of infections in pediatric population; however, information about the behavior of such infections in this population is limited. The aim of the study was to describe the clinical, epidemiological, and molecular characteristics of infections caused by methicillin-susceptible and resistant S. aureus (MSSA-MRSA) in a pediatric population. A cross-sectional descriptive study in patients from birth to 14 years of age from three high-complexity institutions was conducted (2008-2010). All patients infected with methicillin-resistant S. aureus and a representative sample of patients infected with methicillin-susceptible S. aureus were included. Clinical and epidemiological information was obtained from medical records and molecular characterization included spa typing, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). In addition, staphylococcal cassette chromosome mec (SCCmec) and virulence factor genes were detected. A total of 182 patients, 65 with methicillin-susceptible S. aureus infections and 117 with methicillin-resistant S. aureus infections, were included in the study; 41.4% of the patients being under 1 year. The most frequent infections were of the skin and soft tissues. Backgrounds such as having stayed in day care centers and previous use of antibiotics were more common in patients with methicillin-resistant S. aureus infections (p≤0.05). Sixteen clonal complexes were identified and methicillin-susceptible S. aureus strains were more diverse. The most common cassette was staphylococcal cassette chromosomemec IVc (70.8%), which was linked to Panton-Valentine leukocidin (pvl). In contrast with other locations, a prevalence of infections in children under 1 year of age in the city could be observed; this emphasizes the importance of epidemiological knowledge at the local level. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights

In-Use Evaluation of Peracetic Acid for High-Level Disinfection of Endoscopes.

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Chenjiao, Wu; Hongyan, Zhang; Qing, Gu; Xiaoqi, Zhong; Liying, Gu; Ying, Fang

2016-01-01

Many high-level disinfectants have been used for disinfection of endoscopes such as 2% glutaraldehyde (GA), 0.55% ortho-phthalaldehyde (OPA), and peracetic acid (PAA). Both GA and OPA are widely used in disinfection of endoscopes and have been previously discussed, but there is little research on the practical use of PAA as an endoscope disinfectant. An experimental model of a flexible gastrointestinal endoscope being contaminated with 9 strains of microorganism was designed. After the cleaning and disinfecting procedure was completed, we evaluated the biocidal activity (850 ppm PAA, 2% GA, and 0.55% OPA) on our flexible gastrointestinal endoscope model. We also evaluated sterilization effectiveness of PAA on other bacteria, including some antibiotic-resistant bacteria (methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, and Clostridium difficile). The residual bacterial colony count number of the PAA-disinfected endoscope was significantly lower than that of the GA- and OPA-disinfected endoscopes. The biocidal effect and efficiency of the endoscope disinfection by PAA appeared to be better than either the GA- or OPA-disinfected endoscope. PAA has demonstrated a good sterilization effect on other bacterial species; of particular note are common antibiotic-resistant bacteria such as methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, and Clostridium difficile. The results of this study demonstrate that PAA is a fast and effective high-level disinfectant for use in the reprocessing of flexible endoscopes.

Antibiotic resistance patterns of coagulase-negative staphylococcus strains isolated from blood cultures of septicemic patients in Turkey.

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Koksal, F; Yasar, H; Samasti, M

2009-01-01

The aim of this study is to determine antibiotic resistance patterns and slime production characteristics of coagulase-negative Staphylococci (CoNS) caused nosocomial bacteremia. A total of 200 CoNS strains were isolated from blood samples of patients with true bacteremia who were hospitalized in intensive care units and in other departments of Istanbul University Cerrahpasa Medical Hospital between 1999 and 2006. Among 200 CoNS isolates, Staphylococcus epidermidis was the most prevalent species (87) followed by Staphylococcus haemolyticus (23), Staphylococcus hominis (19), Staphylococcus lugdunensis (18), Staphylococcus capitis (15), Staphylococcus xylosus (10), Staphylococcus warneri (8), Staphylococcus saprophyticus (5), Staphylococcus lentus (5), Staphylococcus simulans (4), Staphylococcus chromogenes (3), Staphylococcus cohnii (1), Staphylococcus schleiferi (1), and Staphylococcus auricularis (1). Resistance to methicillin was detected in 67.5% of CoNS isolates. Methicillin-resistant CoNS strains were determined to be more resistant to antibiotics than methicillin-susceptible CoNS strains. Resistance rates of methicillin-resistant and methicillin-susceptible CoNS strains to the antibacterial agents, respectively, were as follows: gentamicin 90% and 17%, erythromycin 80% and 37%, clindamycin 72% and 18%, trimethoprim-sulfamethoxazole 68% and 38%, ciprofloxacin 67% and 23%, tetracycline 60% and 45%, chloramphenicol 56% and 13% and fusidic acid 25% and 15%. None of the strains were resistant to vancomycin and teicoplanin. Slime production was detected in 86 of 200 CoNS strains. Resistance to methicillin was found in 81% of slime-positive and in 57% of slime-negative strains. Our results indicated that there is a high level of resistance to widely used agents in causative methicillin-resistant CoNS strains. However fusidic acid has the smallest resistance ratio, with the exception of glycopeptides. Additionally, most S. epidermidis strains were slime

Molecular Characterization of Methicillin Resistant Staphylococcus aureus Strains Isolated from Intensive Care Units in Iran: ST22-SCCmec IV/t790 Emerges as the Major Clone.

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Goudarzi, Mehdi; Goudarzi, Hossein; Sá Figueiredo, Agnes Marie; Udo, Edet E; Fazeli, Maryam; Asadzadeh, Mohammad; Seyedjavadi, Sima Sadat

2016-01-01

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) in different patient populations is a major public health concern. This study determined the prevalence and distribution of circulating molecular types of MRSA in hospitalized patients in ICU of hospitals in Tehran. A total of 70 MRSA isolates were collected from patients in eight hospitals. Antimicrobial resistance patterns were determined using the disk diffusion method. The presence of toxin encoding genes and the vancomycin resistance gene were determined by PCR. The MRSA isolates were further analyzed using multi-locus sequence, spa, SCCmec, and agr typing. The MRSA prevalence was 93.3%. Antimicrobial susceptibility testing revealed a high resistance rate (97.1%) to ampicillin and penicillin. The rate of resistance to the majority of antibiotics tested was 30% to 71.4%. Two isolates belonging to the ST22-SCCmec IV/t790 clone (MIC ≥ 8 μg/ml) had intermediate resistance to vancomycin. The majority of MRSA isolates (24.3%) were associated with the ST22-SCCmec IV/t790 clone; the other MRSA clones were ST859-SCCmec IV/t969 (18.6%), ST239-SCCmec III/t037 (17.1%), and ST291-SCCmec IV/t030 (8.6%). The circulating MRSA strains in Iranian hospitals were genetically diverse with a relatively high prevalence of the ST22-SCCmec IV/t790 clone. These findings support the need for future surveillance studies on MRSA to better elucidate the distribution of existing MRSA clones and detect emergence of new MRSA clones.

Antibacterial Activity and Antibiotic-Enhancing Effects of Honeybee Venom against Methicillin-Resistant Staphylococcus aureus

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Sang Mi Han

2016-01-01

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA, along with other antibiotic resistant bacteria, has become a significant social and clinical problem. There is thus an urgent need to develop naturally bioactive compounds as alternatives to the few antibiotics that remain effective. Here we assessed the in vitro activities of bee venom (BV, alone or in combination with ampicillin, penicillin, gentamicin or vancomycin, on growth of MRSA strains. The antimicrobial activity of BV against MRSA strains was investigated using minimum inhibitory concentrations (MIC, minimum bactericidal concentrations (MBC and a time-kill assay. Expression of atl which encodes murein hydrolase, a peptidoglycan-degrading enzyme involved in cell separation, was measured by reverse transcription-polymerase chain reaction. The MICs of BV were 0.085 µg/mL and 0.11 µg/mL against MRSA CCARM 3366 and MRSA CCARM 3708, respectively. The MBC of BV against MRSA 3366 was 0.106 µg/mL and that against MRSA 3708 was 0.14 µg/mL. The bactericidal activity of BV corresponded to a decrease of at least 3 log CFU/g cells. The combination of BV with ampicillin or penicillin yielded an inhibitory concentration index ranging from 0.631 to 1.002, indicating a partial and indifferent synergistic effect. Compared to ampicillin or penicillin, both MRSA strains were more susceptible to the combination of BV with gentamicin or vancomycin. The expression of atl gene was increased in MRSA 3366 treated with BV. These results suggest that BV exhibited antibacterial activity and antibiotic-enhancing effects against MRSA strains. The atl gene was increased in MRSA exposed to BV, suggesting that cell division was interrupted. BV warrants further investigation as a natural antimicrobial agent and synergist of antibiotic activity.

Modeling of the bacterial mechanism of methicillin-resistance by a systems biology approach.

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Ida Autiero

Full Text Available BACKGROUND: A microorganism is a complex biological system able to preserve its functional features against external perturbations and the ability of the living systems to oppose to these external perturbations is defined "robustness". The antibiotic resistance, developed by different bacteria strains, is a clear example of robustness and of ability of the bacterial system to acquire a particular functional behaviour in response to environmental changes. In this work we have modeled the whole mechanism essential to the methicillin-resistance through a systems biology approach. The methicillin is a beta-lactamic antibiotic that act by inhibiting the penicillin-binding proteins (PBPs. These PBPs are involved in the synthesis of peptidoglycans, essential mesh-like polymers that surround cellular enzymes and are crucial for the bacterium survival. METHODOLOGY: The network of genes, mRNA, proteins and metabolites was created using CellDesigner program and the data of molecular interactions are stored in Systems Biology Markup Language (SBML. To simulate the dynamic behaviour of this biochemical network, the kinetic equations were associated with each reaction. CONCLUSIONS: Our model simulates the mechanism of the inactivation of the PBP by methicillin, as well as the expression of PBP2a isoform, the regulation of the SCCmec elements (SCC: staphylococcal cassette chromosome and the synthesis of peptidoglycan by PBP2a. The obtained results by our integrated approach show that the model describes correctly the whole phenomenon of the methicillin resistance and is able to respond to the external perturbations in the same way of the real cell. Therefore, this model can be useful to develop new therapeutic approaches for the methicillin control and to understand the general mechanism regarding the cellular resistance to some antibiotics.

Factors associated with methicillin-resistant coagulase-negative staphylococci as causing organisms in deep sternal wound infections after cardiac surgery

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R. Sommerstein

2015-07-01

Full Text Available Established preoperative antibiotic prophylaxis in cardiac surgery is ineffective against methicillin-resistant coagulase-negative staphylococci (CoNS. This case–control study aimed to determine factors predicting deep sternal wound infections due to methicillin-resistant CoNS. All cardiac surgery patients undergoing sternotomy between June 2009 and March 2013 prospectively documented in a Swiss tertiary care center were included. Among 1999 patients, 82 (4.1% developed deep sternal wound infection. CoNS were causal in 36 (44% patients, with 25/36 (69% being methicillin resistant. Early reintervention for noninfectious causes (odds ratio (OR 4.3; 95% confidence interval (CI 1.9–9.5 was associated with methicillin-resistant CoNS deep sternal wound infection. Among CoNS deep sternal wound infection, perioperative antimicrobial therapy (p 0.002, early reintervention for noninfectious causes (OR 7.9; 95% CI 0.9–71.1 and time between surgery and diagnosis of infection over 21 days (OR 10.8; 95% CI 1.2–97.8 were associated with methicillin resistance. These findings may help to better tailor preoperative antimicrobial prophylaxis.

Annual Surveillance Summary: Methicillin-Resistant Staphylococcus aureus (MRSA) Infections in the Military Health System (MHS), 2016

Science.gov (United States)

2017-06-01

Classifications .................................................................. 7 Section B – Antimicrobial Resistance and Use...368-2017 Section B – Antimicrobial Resistance and Use Regional Multidrug Resistance The 2016 annual incidence rate of MRSA among all MHS...Annual Surveillance Summary: Methicillin- Resistant Staphylococcus aureus (MRSA) Infections in the Military

Vancomycin resistant enterococci (VRE in Swedish sewage sludge

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Aspan Anna

2009-05-01

Full Text Available Abstract Background Antimicrobial resistance is a serious threat in veterinary medicine and human healthcare. Resistance genes can spread from animals, through the food-chain, and back to humans. Sewage sludge may act as the link back from humans to animals. The main aims of this study were to investigate the occurrence of vancomycin resistant enterococci (VRE in treated sewage sludge, in a Swedish waste water treatment plant (WWTP, and to compare VRE isolates from sewage sludge with isolates from humans and chickens. Methods During a four month long study, sewage sludge was collected weekly and cultured for VRE. The VRE isolates from sewage sludge were analysed and compared to each other and to human and chicken VRE isolates by biochemical typing (PhenePlate, PFGE and antibiograms. Results Biochemical typing (PhenePlate-FS and pulsed field gel electrophoresis (PFGE revealed prevalence of specific VRE strains in sewage sludge for up to 16 weeks. No connection was found between the VRE strains isolated from sludge, chickens and humans, indicating that human VRE did not originate from Swedish chicken. Conclusion This study demonstrated widespread occurrence of VRE in sewage sludge in the studied WWTP. This implies a risk of antimicrobial resistance being spread to new farms and to the society via the environment if the sewage sludge is used on arable land.

Rapid and easy detection of low-level resistance to vancomycin in methicillin-resistant Staphylococcus aureus by matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

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Asakura, Kota; Azechi, Takuya; Sasano, Hiroshi; Matsui, Hidehito; Hanaki, Hideaki; Miyazaki, Motoyasu; Takata, Tohru; Sekine, Miwa; Takaku, Tomoiku; Ochiai, Tomonori; Komatsu, Norio; Shibayama, Keigo; Katayama, Yuki; Yahara, Koji

2018-01-01

Vancomycin-intermediately resistant Staphylococcus aureus (VISA) and heterogeneous VISA (hVISA) are associated with treatment failure. hVISA contains only a subpopulation of cells with increased minimal inhibitory concentrations, and its detection is problematic because it is classified as vancomycin-susceptible by standard susceptibility testing and the gold-standard method for its detection is impractical in clinical microbiology laboratories. Recently, a research group developed a machine-learning classifier to distinguish VISA and hVISA from vancomycin-susceptible S. aureus (VSSA) according to matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) data. Nonetheless, the sensitivity of hVISA classification was found to be 76%, and the program was not completely automated with a graphical user interface. Here, we developed a more accurate machine-learning classifier for discrimination of hVISA from VSSA and VISA among MRSA isolates in Japanese hospitals by means of MALDI-TOF MS data. The classifier showed 99% sensitivity of hVISA classification. Furthermore, we clarified the procedures for preparing samples and obtaining MALDI-TOF MS data and developed all-in-one software, hVISA Classifier, with a graphical user interface that automates the classification and is easy for medical workers to use; it is publicly available at https://github.com/bioprojects/hVISAclassifier. This system is useful and practical for screening MRSA isolates for the hVISA phenotype in clinical microbiology laboratories and thus should improve treatment of MRSA infections.

In vitro ciprofloxacin resistance patterns of gram positive bacteria isolated from clinical specimens in a teaching hospital in Saudi Arabia

International Nuclear Information System (INIS)

Akhtar, N.; Alzahrani, A.; Obeid, O.El-Treify; Dassal, D.

2009-01-01

Over the last few decades the ever-increasing level of bacterial resistance to antimicrobials has been a cause of worldwide concern. Fluoroquinolones, particularly ciprofloxacin has been used indiscriminately for both gram-positive and gram-negative bacterial infections. The increased use of ciprofloxacin has led to a progressive loss of bacterial susceptibility to this antibiotic. Therefore it is necessary to have update knowledge of resistance pattern of bacteria to this antibiotic so that alternate appropriate antibiotics can be used for ciprofloxacin-resistant bacterial infections. Objective: To evaluate the trends of ciprofloxacin resistance pattern in commonly isolated gram positive bacteria over time in a Saudi Arabian teaching hospital. Methods: A retrospective analysis was carried out for ciprofloxacin susceptibility patterns of 5534 isolates of gram-positive bacteria isolated from clinical specimens submitted to microbiology laboratories at King Fahd Hospital of the University (KFHU), Al-Khobar, Saudi Arabia during the period from January 2002 to August 2005. Results: Increase in ciprofloxacin resistance rates with some fluctuations, among these isolates, were observed. For Staphylococcus aureus, it varied from 4.62, 1.83, 7.01 and 3.98%, methicillin resistant Staphylococcus aureus (MRSA) 97.92, 97.75, 87.01 and 88.26%, Streptococcus pyogenes 5.35, 4.47, 14.44 and 3.53% during the years 2002, 2003, 2004 and 2005 respectively. Cirprofloxacin resistance during the years 2002, 2004 and 2005 for other isolates was as follows: Streptococcus pneumoniae, 30.23, 23.02 and 26.47%; enterococcus group D, 43.05, 20.68 and 57.03% and non-enterococcus group D, 62.96, 76.92 and 87.50% respectively. Conclusion: Ciprofloxacin resistance in gram positive bacterial clinical isolates particularly Staphylococcus aureus, methicillin resistant Staphylococcus aureus (MRSA) enterococcus group D, and non-enterococcus group D, has greatly increased and ciprofloxacin no more remains

DAYA HAMBAT SARI TANAMAN OBAT TERHADAP PERTUMBUHAN BAKTERI STRAIN Methicillin Resistant Staphylococcus aureus (MRSA

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Dwi Hilda Putri

2016-09-01

Full Text Available Staphylococcus aureus infection can be treated with Methicilin, β lactam class of antibiotics that have drug targets in the cell wall. Bacteria S. aureus that is resistant to methicillin called methicillin-resistant Staphylococcus aureus (MRSA. One alternative that can be used in strains of antibiotic-resistant bacteria that have this is to use medicinal plants. This study aimed to know the ability of medicinal plant extracts inhibit the growth of bacterial strains of MRSA. This kind of research is experimental research. Medicinal plants tested were Garlic, Turmeric, Aloe Vera, Daun Salam, Curcuma, Ginger, Betel Leaf and Alpinia galanga. As a control, which is used Amphicillin, β lactam antibiotic class. The method used to determine the diameter of inhibition area of medicinal plant extracts is paper diffusion method. The results showed that all medicinal plants can inhibit bacterial growth of MRSA strains characterized by the inhibition zone formed on each treatment. The ability of garlic and turmeric extract better than Amphicillin and other medicinal plants to inhibit bacterial growth of MRSA strains. Kata kunci: inhibit,  growth, bacteria, methicillin resistant staphylococcus aureus (MRSA

Characterization of Hospital-Associated Lineages of Ampicillin-Resistant Enterococcus faecium from Clinical Cases in Dogs and Humans

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Cindy-Love eTremblay

2013-08-01

Full Text Available Ampicillin-resistant Enterococcus faecium (ARE has rapidly emerged worldwide and is one of the most important nosocomial pathogens. However, very few reports are available on ARE isolates from canine clinical cases. The objective of this study was to characterize ARE strains of canine clinical origin from a veterinary teaching hospital in Canada and to compare them with human strains. Ten ARE strains from dogs and humans were characterized by multilocus sequence typing (MLST, pulsed field gel electrophoresis (PFGE, antibiotic susceptibility and biofilm activities, presence of rep-families, CRISPR-cas and putative virulence genes. All ARE strains (n = 10 were resistant to ciprofloxacin and lincomycin. Resistances to tetracycline (n = 6, macrolides (n = 6, and to high concentrations of gentamicin, kanamycin and streptomycin (n = 5 were also observed. Canine ARE isolates were found to be susceptible to vancomycin whereas resistance to this antibiotic was observed in human strains. Ampicillin resistance was linked to PBP5 showing mutations at 25 amino acid positions. Fluoroquinolone resistance was attributable to ParC, GyrA, and GyrB mutations. Data demonstrated that all canine ARE were acm (collagen binding protein-positive and that most harbored the efaAfm gene, encoding for a cell wall adhesin. Biofilm formation was observed in two human strains but not in canine strains. Two to five rep-families were observed per strain but no CRISPR sequences were found. A total of six STs (1, 18, 65, 202, 205, and 803 were found with one belonging to a new ST (ST803. These STs were identical or closely related to human hospital-associated lineages. This report describes for the first time the characterization of canine ARE hospital-associated strains in Canada and also supports the importance of prudent antibiotic use in veterinary medicine to avoid zoonotic spread of canine ARE.

Antibacterial activity of mupirocin (pseudomonic Acid A) against, clinical isolates of methicillin-resistant staphylococcus aureus

International Nuclear Information System (INIS)

Farooq, M.; Abbasi, S.A.; Butt, T.; Arain, M.A

2010-01-01

Colonized patients and health care workers are the main source of spread of methicillin resistant Staphylococcus aureus (MRSA) in hospitals. The elimination of nasal colonized MRSA plays a crucial role in infection control protocols. Mupirocin (pseudomonic acid A) is used for eradication of MRSA nasal carriage. Increasing use of pseudomonic acid A (mupirocin) has led to emergence of resistance. Objective To determine low and high level resistance of MRSA isolates from clinical specimens against mupirocin. Place and duration of study: Study was conducted at Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi from July 2006 to June 2007. Material and methods Three hundred methicillin-resistant Staphylococcus aureus isolates were studied. All clinical specimens were processed for culture and sensitivity. Staphylococcus aureus isolates were tested for methicillin resistance using 1 micro g oxacillin disk. The isolates were further tested by PCR for the presence of mecA gene. Minimum Inhibitory Concentration (MIC) of mupirocin against MRSA isolates was determined using agar dilution technique. Results Out of 300 MRSA isolates, 98% were found to have MlC against mupirocin as smaller than 4 micro g/mL. Remaining 2% isolates revealed low level resistance (MIC greater than 8 micro g/mL to 256 micro g/mL), no high level resistance (MIC greater than 512 micro g/mL) against mupirocin was detected. Conclusions: High level mupirocin resistance has not emerged so far in our setup. Due to increasing use of mupirocin, emergence of resistance against mupirocin among MRSA is a strong possibility. Strategy encompassing rational use of antimicrobials, hospital infection control, surveillance for the detection of mupirocin resistance and judicious use of this agent is required. (author)

Methicillin-Resistant Staphylococcus aureus (MRSA Detection from the Hands of Jatinangor Community Health Center’s Health Care Providers

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Jeevanisha Patmanathan

2015-06-01

Full Text Available Background: Methicillin-resistant Staphylococcus aureus is a bacterium that is resistance towards β-lactam antibiotics, and it seems to be one of the leading causes of nosocomial infections. Hands of the health care workers are said to be the main source for the nosocomial transmission. Thus, the study aims to determine methicillin-resistant S. aureus from the hands of Jatinangor Community Health Center’s health care workers. Methods: Samples were taken from the hands of 30 Jatinangor Community Health Center’s staffs, including medical and paramedical; from October 2012 to November 2012. Then, these samples underwent further laboratory examinations, starting from culture, identification and susceptibility test towards cefoxitin, in identifying methicillin-resistant S. aureus. Results: Out of the 30 samples taken, 6 samples (20% were positive for S. aureus isolates. In which, 4 (13.33% of the samples were positive for methicillin-resistant S. aureus. Conclusions: Since, health care workers are the main people in contact with patients and maintaining proper hand hygiene makes a huge difference; hand hygiene should be given adequate attention for the benefit of all.

The potential of vancomycin-resistant enterococci to persist in fermented and pasteurised meat products.

Science.gov (United States)

Houben, J H

2003-11-15

Experiments with 148 isolates of vancomycin-resistant enterococci (VRE) were performed to assess their potential to persist and grow in fermented sausages and pasteurised meat products. All strains were meat isolates and Van-type A, except a single VanC1 strain. In total, 143 strains of Enterococcus faecium were involved. Eight selected strains were examined for their potential to grow at high salt and nitrite levels and at reduced pH. The same isolates were used in experiments with fermented sausages. All available strains were subjected to heating tests in meat suspensions with added curing ingredients. All but one of the eight tested isolates grew at pH 4.0 in tryptone soya broth (TSB). With the combination of 8% w/w NaCl, 400 ppm NaNO2 and 0.5% w/w glucose in the meat suspension, all isolates grew at 37 degrees C, whereas none grew at 7 degrees C even after 56 days. With the addition of 10% w/w NaCl, 200 ppm NaNO2 and 0.5% w/w glucose, still one E. faecium isolate grew at 37 degrees C, although very slowly. Overall, the strains tolerated high salt and nitrite concentrations and reduced pH very well, even beyond levels applied in the regular production of fermented and/or pasteurised meat products. The tested strains could be isolated after the fermentation and further ripening of "boerenmetworst" and "snijworst". Overall, their colony counts decreased on average about 1 log-unit over a period of 60 days after batter manufacture. All 148 isolates demonstrated a relatively weak thermal resistance compared to results for selected vancomycin-sensitive enterococci strains reported in the literature and to results collected under identical experimental conditions in this laboratory. None of the strains (log inoculation level about 5-6 ml(-1) for each isolate) could be cultured after heating at 70 degrees C for 10 min.

Antimicrobial susceptibility of microorganisms isolated from sputum culture of patients with cystic fibrosis: Methicillin-resistant Staphylococcus aureus as a serious concern.

Science.gov (United States)

Mazloomi Nobandegani, Narges; Mahmoudi, Shima; Pourakbari, Babak; Hosseinpour Sadeghi, Reihaneh; Najafi Sani, Mehri; Farahmand, Fateme; Motamed, Farzaneh; Nabavizadeh Rafsanjani, Raheleh; Mamishi, Setareh

2016-11-01

Infection is a major cause of morbidity and mortality in patients with cystic fibrosis (CF). Antimicrobial resistance of the bacterial spp. particularly methicillin resistance in Staphylococcus aureus has caused a lot of attention. The aim of this study was to describe the prevalence of S. aureus, Pseudomonas aeruginosa and Burkholderia cepacia-complex as well as their antimicrobial susceptibility patterns in CF patients in an Iranian referral pediatrics Hospital. From March 2011 until February 2012, 172 samples were collected at the Children Medical Center (CMC), an Iranian referral hospital in Tehran, Iran. Sputum specimens were cultured for the following bacterial pathogens: P. aeruginosa, S. aureus, B. cepacia complex. Antimicrobial susceptibility was performed according to the Clinical Laboratory Standards Institute recommendations. In our study, 54% of the patients (n = 93) harbored at least once S. aureus, 30% (n = 52) P. aeruginosa, and 2% (n = 3) Burkholderia cepacia. In 40 patients (23%), none of these organisms was grown. An increasing colonization rate of P. aeruginosa in the second decade of life was found. In contrast, the colonization rate of S. aureus was constant in both decades of life. Methicillin resistant S. aureus (MRSA) was detected in 40 isolates (43%). Among MRSA, no resistance against vancomycin, linezolid and quinupristin/dalfopristin occurred. The susceptibility of P. aeruginosa isolates to meropenem, imipenem, doripenem, levofloxacin and polymixin B were more than 90%. The prevalence of MRSA has been rising. Since its impact on clinical outcomes, optimal prevention and treatment strategies are unclear, further studies to expand the knowledge about the infection control strategies and MRSA treatment are highly recommended. Copyright © 2016 Elsevier Ltd. All rights reserved.

Methicillin-susceptible and -resistant Staphylococcus aureus with high-level antiseptic and low-level mupirocin resistance in Malaysia.

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Ghasemzadeh-Moghaddam, Hamed; van Belkum, Alex; Hamat, Rukman Awang; van Wamel, Willem; Neela, Vasanthakumari

2014-10-01

The prevalence and spread of mupirocin and antiseptic resistance among colonizing and infectious Staphylococcus aureus were determined. S. aureus isolated from anterior nares and infection sites of patients hospitalized in the largest tertiary care referral hospital in Malaysia was investigated for mupirocin and antiseptic susceptibility testing, and for PCR detection of mupA, qacA/B, and smr genes. Twelve isolates showed resistance to mupirocin by disk diffusion, of which 10 (3.8%) harbored the mupA gene. Minimum inhibitory concentrations (MICs) ranged from 64 to 768 μg/ml for mupA positive and below 46 μg/ml for negative isolates. The mupA was more common among ST239 isolates (70%). The qacA/B was carried in 67 out of 95 methicillin-resistant Staphylococcus aureus (MRSA) (70.5%) and 3 out of 164 methicillin-susceptible Staphylococcus aureus (MSSA) (1.8%), while smr was carried in 6 out of 95 MRSA (6.3%) strains. MICs ranged from 3.9 to 15.6 μg/ml for benzethonium chloride (BTC) and benzalkonium chloride (BKC), and from 10.3 to 20.7 μg/ml for chlorhexidine digluconate (CHG). Isolates with qacA/B and smr or qacA/B alone showed higher MIC (20.7 μg/ml for CHG and 15.6 μg/ml for BTC and BKC) than the isolates that lacked antiseptic resistance genes (10.3 μg/ml for CHG and 3.9 μg/ml for BTC and BKC). In 16 cases, ST239 was isolated from the infection site and the nares simultaneously, and shared identical resistance patterns (qacAB or qacAB+smr), suggesting possible endogenous infection. Spread of low-level mupirocin resistance expressing ST239 MRSA and high-level resistance expressing emerging ST1, co-existing with antiseptic-resistant genes showing elevated MICs, should be monitored for effective infection control.

Recommendations for Methicillin-Resistant Staphylococcus aureus Prevention in Adult ICUs: A Cost-Effectiveness Analysis.

Science.gov (United States)

Whittington, Melanie D; Atherly, Adam J; Curtis, Donna J; Lindrooth, Richard C; Bradley, Cathy J; Campbell, Jonathan D

2017-08-01

Patients in the ICU are at the greatest risk of contracting healthcare-associated infections like methicillin-resistant Staphylococcus aureus. This study calculates the cost-effectiveness of methicillin-resistant S aureus prevention strategies and recommends specific strategies based on screening test implementation. A cost-effectiveness analysis using a Markov model from the hospital perspective was conducted to determine if the implementation costs of methicillin-resistant S aureus prevention strategies are justified by associated reductions in methicillin-resistant S aureus infections and improvements in quality-adjusted life years. Univariate and probabilistic sensitivity analyses determined the influence of input variation on the cost-effectiveness. ICU. Hypothetical cohort of adults admitted to the ICU. Three prevention strategies were evaluated, including universal decolonization, targeted decolonization, and screening and isolation. Because prevention strategies have a screening component, the screening test in the model was varied to reflect commonly used screening test categories, including conventional culture, chromogenic agar, and polymerase chain reaction. Universal and targeted decolonization are less costly and more effective than screening and isolation. This is consistent for all screening tests. When compared with targeted decolonization, universal decolonization is cost-saving to cost-effective, with maximum cost savings occurring when a hospital uses more expensive screening tests like polymerase chain reaction. Results were robust to sensitivity analyses. As compared with screening and isolation, the current standard practice in ICUs, targeted decolonization, and universal decolonization are less costly and more effective. This supports updating the standard practice to a decolonization approach.

SDS-PAGE and gel IEF – tool for differentiation of methicillin-resistant and methicillin-sensitive strains of Staphylococcus aureus

Czech Academy of Sciences Publication Activity Database

Tesařová, Marie; Horká, Marie; Moravcová, Dana; Svojanovská, Lenka; Mlynariková, K.; Růžička, F.

2016-01-01

Roč. 72, č. 3 (2016), s. 315-320 ISSN 0343-8651 R&D Projects: GA MV VG20112015021 Institutional support: RVO:68081715 Keywords : methicillin-resistant and methicillin-sensitive Staphylococcus aureus * sodium dodecylsulphate polyacrylamide gel electrophoresis * gel isoelectric focusing * precipitated proteins Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.322, year: 2016 http://hdl.handle.net/11104/0251069

Weissella confusa: a rare cause of vancomycin-resistant Gram-positive bacteraemia.

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Kumar, Anil; Augustine, Deepthi; Sudhindran, S; Kurian, Anu M; Dinesh, Kavitha R; Karim, Shamsul; Philip, Rosamma

2011-10-01

We describe a case of bacteraemia caused by Weissella confusa in a 48-year-old male who was operated on for adenocarcinoma of the gastro-oesophageal junction and maintained on total parenteral nutrition. Blood cultures were positive for a vancomycin-resistant streptococcus-like organism which was identified as W. confusa by 16S rRNA gene sequencing.

Prevalence of methicillin-resistant Staphylococcus aureus skin and nasal carriage isolates from bovines and its antibiogram

Directory of Open Access Journals (Sweden)

Alok Kumar

2017-06-01

Full Text Available Aim: This study was conducted to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA in cattle and buffalo and to study their antibiotic resistance pattern. Materials and Methods: A total of 136 samples (skin and nasal swab from cattle and buffalo were collected. MRSA was identified by conventional bacterial culture techniques which were further confirmed by amplification of S. aureus-specific 16S rRNA by polymerase chain reaction (PCR. The isolates were further analyzed for the presence of mecA gene by PCR. The antimicrobial susceptibility profiling was performed by disc diffusion method. Results: The prevalence of MRSA in the current study was 28.57% and 34.28% in cattle nasal and skin swab, respectively, with an overall prevalence of 31.43% MRSA among cattle. Buffalo nasal and skin sample showed MRSA prevalence of 54.55% and 39.4%, respectively, with 46.9% overall prevalence. PCR could detect mecA gene in 36.4% and 58% MRSA isolates from cattle and buffalo, respectively. Antimicrobial susceptibility test found MRSA resistant to penicillin and oxytetracycline (88% each, cefoxitin (75%, cotrimoxazole (62%, and amoxyclav (50%. 100% sensitivity was observed against ciprofloxacin, amikacin, chloramphenicol, and gentamicin. Three (16.7% MRSA isolates from buffalo were found resistant to vancomycin. Conclusion: Cattle and buffalo were identified as a potential carrier of MRSA in Bihar (India. The isolation of vancomycinresistant S. aureus (VRSA in the current study indicates the emergence of VRSA in animal population which may be transmitted to the human beings working in close contact to the animals.

Comparative proteomics of Staphylococcus aureus and the response of methicillin-resistant and methicillin-sensitive strains to Triton X-100

DEFF Research Database (Denmark)

Cordwell, Stuart J; Larsen, Martin Røssel; Cole, Rebecca T

2002-01-01

profiles of S. aureus strains COL (methicillin-resistant) and 8325 (methicillin-sensitive). Reference mapping via this approach identified 377 proteins that corresponded to 266 distinct ORFs. Amongst these identified proteins were 14 potential virulence factors. The production of 41 'hypothetical' proteins....... Comparative maps were used to characterize the S. aureus response to treatment with Triton X-100 (TX-100), a detergent that has been shown to reduce methicillin resistance independently of an interaction with the mecA-encoded penicillin-binding protein 2a. In response to growth of the bacteria in the presence...... of TX-100, 44 protein spots showed altered levels of abundance, and 11 of these spots were found only in COL. The products of genes regulated by sigma(B) (the alternative sigma factor), including Asp23 and three proteins of unknown function, and SarA (a regulator of virulence genes) were shown...

The Epidemiology of Methicillin-Resistant Staphylococcus aureus (MRSA) in Germany

NARCIS (Netherlands)

Koeck, Robin; Mellmann, Alexander; Schaumburg, Frieder; Friedrich, Alexander W.; Kipp, Frank; Becker, Karsten

2011-01-01

Background: For decades, methicillin-resistant Staphylococcus aureus (MRSA) has been a major cause of infection in hospitals and nursing homes (health care-associated MRSA, HA-MRSA). Beginning in the late 1990s, many countries have also experienced a rising incidence of MRSA infection outside of the

Unraveling the dynamics of community-associated methicillin-resistant Staphylococcus aureus

NARCIS (Netherlands)

Bootsma, M.C.; Bonten, M.J.M.

2013-01-01

Since the first description of the community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strain USA300 [1] in the 1990s, this pathogen has emerged worldwide [2]. Within a decade, USA300 has become the most prevalent cause of community-acquired S. aureus infections in many

Rapid control of a methicillin resistant Staphylococcus aureus (MRSA) outbreak in a medical surgical intensive care unit (ICU).

Science.gov (United States)

Khan, Anjum; Lampitoc, Marianita; Salaripour, Maryam; McKernan, Patricia; Devlin, Roslyn; Muller, Matthew P

2009-01-01

Outbreaks of methicillin resistant Staphylococcus aureus in the intensive care unit setting can be prolonged and difficult to control. This report describes the rapid control of an outbreak of methicillin resistant Staphylococcus aureus in a 24-bed open-concept medical surgical intensive care unit with a baseline methicillin resistant Staphylococcus aureus acquisition rate of 1.5 cases per 1000 patient days. This institution's infection control policy mandates an outbreak investigation if two cases of hospital-acquired methicillin resistant Staphylococcus aureus colonization or infection are identified in an intensive care unit within a four-week period. In July 2007, methicillin resistant Staphylococcus aureus was identified in the sputum of two patients within a one-week period. Screening of all patients in the intensive care unit identified one additional case and a fourth case was identified from a clinical specimen before control measures were implemented. Initial control measures included healthcare worker education, enhanced surveillance, patient cohorting, and enhanced environmental cleaning. Despite these measures, three more cases occurred. All patients were then placed in contact isolation, healthcare workers were screened, and the nursing staff was cohorted. After two weeks without a case, two additional cases were identified. Decolonization of all positive patients was initiated. No further cases occurred over a five-week period and the outbreak was declared over. The outbreak resulted in nine cases of methicillin resistant Staphylococcus aureus colonization (n = 8) or infection (n = 1) over an 11-week period. Only one of 175 healthcare workers was colonized and it was not the outbreak strain. Early detection and the stepwise addition of infection control measures resulted in the rapid control of an outbreak of methicillin resistant Staphylococcus aureus in a medical surgical intensive care unit without unit closure. A low threshold of suspicion and

Methicillin-Resistant Staphylococcus aureus from Brazilian Dairy Farms and Identification of Novel Sequence Types.

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Oliveira, C J B; Tiao, N; de Sousa, F G C; de Moura, J F P; Santos Filho, L; Gebreyes, W A

2016-03-01

The aim of this study was to investigate the phenotypic and genotypic diversity and anti-microbial resistance among staphylococci of dairy herds that originated from Paraiba State, north-eastern Brazil, a region where such studies are rare. Milk samples (n = 552) were collected from 15 dairy farms. Isolates were evaluated for anti-microbial susceptibility by Kirby-Bauer disc diffusion method. Confirmation of methicillin-resistant Staphylococcus aureus (MRSA) was performed using multiplex PCR targeting mecA and nuc genes in addition to phenotypic assay based on PBP-2a latex agglutination. Clonal relatedness of isolates was determined by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) genotyping. Staphylococci were detected in 269 (49%) of the samples. Among these, 65 (24%) were S. aureus. The remaining 204 isolates were either coagulase-negative staphylococci (n = 188; 70%) or coagulase positive other than S. aureus (n = 16; 6%). Staphylococci were cultured in seven (35%) of the 20 hand swab samples, from which five isolates were S. aureus. The isolates were most commonly resistant against penicillin (43%), ampicillin (38%) and oxacillin (27%). The gene mecA was detected in 21 S. aureus from milk and in one isolate from a milker's hand. None of the isolates were resistant to vancomycin. PFGE findings showed high clonal diversity among the isolates. Based on MLST, we identified a total of 11 different sequence types (STs 1, 5, 6, 83, 97, 126, 1583, 1622, 1623, 1624 and 1625) with four novel STs (ST1622-ST1625). The findings show that MRSA is prevalent in milk from semi-extensive dairy cows in north-eastern Brazil, and further investigation on its extent in various types of milk production systems and the farm-to-table continuum is warranted. © 2015 Blackwell Verlag GmbH.

In vitro susceptibility of chloramphenicol against methicillin-resistant staphylococcus aureus

International Nuclear Information System (INIS)

Fayyaz, M.; Mirza, I.A.; Hussain, A.; Abbasi, S.A.; Ali, S.; Ahmed, Z.

2013-01-01

To determine the in vitro susceptibility of chloramphenicol against methicillin-resistant Staphylococcus aureus. Study Design: Cross-sectional study. Place and Duration of Study: Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi, from January to June 2012. Methodology: One hundred and seventy four isolates of methicillin-resistant Staphylococcus aureus were included in this study using cefoxitin (30 A g) disc for detection. Minimum inhibitory concentration (MIC) of chloramphenicol against MRSA was determined by using E-strip (AB BIO DISK). The susceptibility was determined by swabbing the Mueller-Hinton agar (MHA) plates with the resultant saline suspension of MRSA and applying E-strip of chloramphenicol from AB Biodisk Sweden and determining the MIC of chloramphenicol (in A g/ml). Clinical and Laboratory Standards Institute (CLSI) recommendations of A=8 A g/ml being sensitive, 16 A g/ml as intermediate and A 32 A g/ml as resistant were followed in interpreting the results. Results: Out of the 174 MRSA isolates, 132 (75.86%) isolates were susceptible to chloramphenicol with MICs of A=8 A g/ml, 38 (21.84%) were resistant A=32 A g/ml while 4 (2.30%) were in intermediate range with MIC of 16 A g/ml. Conclusion: Chloramphenicol has shown good in vitro activity against MRSA and is likely to have a key role in the treatment of MRSA infections providing us a good alternative to newer expensive antimicrobials in resource limited countries. (author)

Repurposing salicylanilide anthelmintic drugs to combat drug resistant Staphylococcus aureus.

Science.gov (United States)

Rajamuthiah, Rajmohan; Fuchs, Beth Burgwyn; Conery, Annie L; Kim, Wooseong; Jayamani, Elamparithi; Kwon, Bumsup; Ausubel, Frederick M; Mylonakis, Eleftherios

2015-01-01

Staphylococcus aureus is a Gram-positive bacterium that has become the leading cause of hospital acquired infections in the US. Repurposing Food and Drug Administration (FDA) approved drugs for antimicrobial therapy involves lower risks and costs compared to de novo development of novel antimicrobial agents. In this study, we examined the antimicrobial properties of two commercially available anthelmintic drugs. The FDA approved drug niclosamide and the veterinary drug oxyclozanide displayed strong in vivo and in vitro activity against methicillin resistant S. aureus (minimum inhibitory concentration (MIC): 0.125 and 0.5 μg/ml respectively; minimum effective concentration: ≤ 0.78 μg/ml for both drugs). The two drugs were also effective against another Gram-positive bacteria Enterococcus faecium (MIC 0.25 and 2 μg/ml respectively), but not against the Gram-negative species Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter aerogenes. The in vitro antimicrobial activity of niclosamide and oxyclozanide were determined against methicillin, vancomycin, linezolid or daptomycin resistant S. aureus clinical isolates, with MICs at 0.0625-0.5 and 0.125-2 μg/ml for niclosamide and oxyclozanide respectively. A time-kill study demonstrated that niclosamide is bacteriostatic, whereas oxyclozanide is bactericidal. Interestingly, oxyclozanide permeabilized the bacterial membrane but neither of the anthelmintic drugs exhibited demonstrable toxicity to sheep erythrocytes. Oxyclozanide was non-toxic to HepG2 human liver carcinoma cells within the range of its in vitro MICs but niclosamide displayed toxicity even at low concentrations. These data show that the salicylanilide anthelmintic drugs niclosamide and oxyclozanide are suitable candidates for mechanism of action studies and further clinical evaluation for treatment of staphylococcal infections.

Virulence-suppressing effects of linezolid on methicillin-resistant Staphylococcus aureus: possible contribution to early defervescence.

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Yoshizawa, Sadako; Tateda, Kazuhiro; Saga, Tomoo; Ishii, Yoshikazu; Yamaguchi, Keizo

2012-04-01

In the present study, immunomodulatory effects of linezolid (LZD) on methicillin-resistance Staphylococcus aureus (MRSA) infections were evaluated. We have retrospectively reviewed treatment effects of LZD on 52 patients with severe MRSA infections. Sixty-four percent of the febrile patients demonstrated significant defervescence within 3 days, despite the presence of positive culture results. We speculated that this finding might be due to early anti-inflammatory effects of LZD, and to investigate this further we initiated in vivo experiments using mice MRSA pneumonia models. Mice were treated with either LZD or vancomycin (VCM) immediately after intranasal administration of MRSA. Bacterial numbers and levels of inflammatory cytokines in the lungs were determined. Although the bacterial burden in the lungs was not apparently different between the two groups, LZD but not VCM treatment significantly reduced induction of inflammatory cytokines in the lungs (P endogenous pyrogens. These data may explain at least in part early defervescence observed in LZD-treated individuals.

Toxic shock syndrome due to community-acquired methicillin-resistant Staphylococcus aureus infection: Two case reports and a literature review in Japan.

Science.gov (United States)

Sada, Ryuichi; Fukuda, Saori; Ishimaru, Hiroyasu

2017-01-01

Community-acquired methicillin-resistant Staphylococcus aureus has been spreading worldwide, including in Japan. However, few cases of toxic shock syndrome caused by Community-acquired methicillin-resistant Staphylococcus aureus have been reported in Japan. We report 2 cases, in middle-aged women, of toxic shock syndrome due to Community-acquired methicillin-resistant Staphylococcus aureus via a vaginal portal of entry. The first patient had used a tampon and the second patient had vaginitis due to a cleft narrowing associated with vulvar lichen sclerosus. Both patients were admitted to our hospital with septic shock and severe acute kidney injury and subsequently recovered with appropriate antibiotic treatment. In our review of the literature, 8 cases of toxic shock syndrome caused by Community-acquired methicillin-resistant Staphylococcus aureus were reported in Japan. In these 8 cases, the main portals of entry were the skin and respiratory tract; however, the portal of entry of Community-acquired methicillin-resistant Staphylococcus aureus from a vaginal lesion has not been reported in Japan previously.

Gene Expression Analysis Reveals New Possible Mechanisms of Vancomycin-Induced Nephrotoxicity and Identifies Gene Markers Candidates

OpenAIRE

Dieterich, Christine; Puey, Angela; Lyn, Sylvia; Swezey, Robert; Furimsky, Anna; Fairchild, David; Mirsalis, Jon C.; Ng, Hanna H.

2008-01-01

Vancomycin, one of few effective treatments against methicillin-resistant Staphylococcus aureus, is nephrotoxic. The goals of this study were to (1) gain insights into molecular mechanisms of nephrotoxicity at the genomic level, (2) evaluate gene markers of vancomycin-induced kidney injury, and (3) compare gene expression responses after iv and ip administration. Groups of six female BALB/c mice were treated with seven daily iv or ip doses of vancomycin (50, 200, and 400 mg/kg) or saline, and...