[Molecular analysis of vancomycin-resistant enterococci isolated from clinical samples] (original) (raw)
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IP innovative publication pvt. ltd, 2019
Aim: The aim of this present study was to investigate the molecular characterization of vancomycin resistant enterococci isolated from various clinical samples. Enterococci are aerobic and anaerobic gram positive cocci found in gastrointestinal tract of humans and other animals. Materials and Methods: Enterococcal isolates were isolated from various clinical samples according to standard protocol and sample size of the study was 52. Vancomycin resistance genes VanA and VanB were detected using conventional PCR. Results: The six isolates resistant to Vancomycin confirmed phenotypically were confirmed using Polymerase Chain Reaction. Conclusion: in the present study conclude that, Vancomycin resistant enterococci is a major health problem in the coming years and hence it is necessary to take all adequate measures to identify the resistant strains
Ann …, 2004
Outbreaks with vancomycin-resistant enterococci (VRE) are being reported with increasing frequency in many countries. While seven glycopeptide resistance genotypes have been described in enterococci, vanA and vanB are the most common resistance genotypes. Aims of this study were to detect antibiotic susceptibilities of 25 Enterococcus faecium strains, which caused an outbreak in a child hospital by Etest, to investigate presence of resistance genes of van A, van B or vanC2 type by PCR, and genotype them by PFGE. All isolates conferred high level vancomycin, teicoplanin, erythromycin, and penicillin resistance (MIC>256 mg/L) and were found to be susceptible to ciprofloxacin (MIC<1 mg/L), tetracycline (MIC<4 µg/ml) and Q-D (MIC<1 mg/L). While all of 25 E. faecium isolates were found to be positive for the presence of the vanA genotype, vanB and vanC2 gene products could not be amplified. All of the isolates could be typed by PFGE generating 10 different DNA fragment profiles. As a conclusion, vanA genotype E. faecium strains may cause outbreaks in Turkey. PCR identification of the van genotype of the infecting strains and genotyping them by PFGE give valuable information in outbreak investigation.
Infection and Drug Resistance
Objective: Nosocomial infections due to vancomycin-resistant enterococci (VRE) are known as a source of spreading these bacteria. The aim of this prospective study was molecular detection of vanA and vanB genes among VRE isolated from patients admitted to intensive care units (ICUs) in Ahvaz in southwest of Iran. Materials and methods: Overall, 243 non-duplicate rectal swab specimens were collected from ICU-hospitalized patients in teaching hospitals affiliated to Ahvaz Jundishapur University of Medical Sciences, Iran. The specimens were inoculated on suitable culture media, and isolates were identified by standard biochemical tests. The susceptibility and resistance of enterococci to 10 antibiotics were determined based on the Clinical and Laboratory Standards Institute guidelines. Resistance to vancomycin was phenotypically detected by vancomycin screening test, and the vanA and vanB genes in vancomycin-resistant isolates were amplified by multiplex PCR method. Results: Of 175 specimens containing enterococci, 129 (73.7%) isolates were detected as Enterococcus faecium and Enterococcus faecalis and 46 (26.3%) isolates as Enterococcus spp. The results of susceptibility test showed high rates of resistance to tetracycline, erythromycin, ciprofloxacin, and ampicillin. Moreover, based on this test, out of 129 Enterococcus isolates, 56 (43.4%) were resistant to vancomycin and teicoplanin. Also, among 59 vancomycin-resistant or semi-susceptible isolates, vanA gene was detected in 54 (91.5%) isolates, while none of the isolates had vanB gene. Conclusion: According to the results of this study, to prevent the spread of vancomycin-resistant Enterococcus strains, especially in nosocomial infections, the susceptibility of isolates should be determined before vancomycin prescription.
2013
Background & objectives: Enterococci have emerged as important nosocomial pathogens and emergence of resistance to many of the antimicrobials used for Gram-positive organisms has made the management of infections due to Enterococcus species difficult. Resistance to glycopeptide antibiotics, especially vancomycin is of special concern. This study was undertaken to perform a phenotypic and genotypic characterization of vancomycin resistant Enterococcus (VRE) isolates obtained from clinical samples in a tertiary care hospital in southern India. Methods: Susceptibility testing was performed for Enterococcus isolates collected over a period of one year (November 2008-October 2009). Minimum inhibitory concentrations (MIC) of vancomycin and teicoplanin were determined for the isolates by the agar dilution method. Genotypic characterization of VRE isolates was done by performing multiplex polymerase chain reaction (PCR) for detecting the various vancomycin resistance genes. Results: Of the ...
2017
A total of 98 vancomycin-resistant Enterococcus faecium (VREF) isolates from four tertiary-care hospitals in Korea during the period between 1998 and 2004 were analyzed for genotypic characteristics using the multiplex PCR, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and esp gene analysis. Ninety-two isolates of VREF with VanA phenotype and five of six isolates with VanB phenotype possessed the vanA gene. MLST analysis revealed 9 sequence types (STs), which belonged to a single clonal complex (CC78, clonal lineage C1). Five strains showing incongruence between phenotype and genotype (VanB-vanA) did not belong to the same genotypic clone. The esp gene was detected in all VREF strains, showing 12 different esp repeat profiles. Data suggest that an epidemic clonal group of VREF, CC78 with esp gene, is also present in Asia and has differentiated into multiple diverse genotypic clones during the evolutionary process.
Innovative Publication, 2016
Background: Enterococci are gram positive cocci which reside as commensal microbial flora in gastrointestinal tract, vagina, biliary tract and male urethra. E.faecalis is the predominant species followed by E.faecium. Resistance against glycopeptides and aminoglycosides are being increasingly demonstrated and that is conferred upon largely by van A gene. Aims: To isolate and speciate Enterococci from various clinical samples, antibiogram pattern determination, followed by genotyping of vancomycin resistant Enterococci. Settings and Design: Prospective study. Materials and Methods: 200 Enterococcal isolates were collected and processed for speciation based on battery of phenotypic characteristics. Antibiotic sensitivity testing was performed as per CLSI guidelines 2014 for glycopeptide and aminoglycoside antibiotics. Enterococci which were resistant to vancomycin were subjected to polymerase chain reaction for van A gene detection. Statistical analysis used: Nil. Results: Of the 200 isolates 5 were resistant to vancomycin and teicoplanin (2.5%), 30 were resistant to high level gentamicin (15%). van A gene was detected in 3 of the 5 vancomycin resistant isolates. E.faecium was observed to be more resistant to the antimicrobials. Conclusions: If the vancomycin resistance in Enterococci gets dispersed throughout the world, it may pose a challenge in the treatment of Gram positive infections and may lead to treatment failure. Further treatment options may not be available. Hence these infections have to be prevented and the sequence of development of resistance to higher drugs has to be controlled by active surveillance and prevention.
International Journal of Enteric Pathogens, 2015
Background: Vancomycin-Resistant Enterococci (VRE) pose an emerging problem in Iran hospitals. Objectives: The present study was undertaken to determine the prevalence of van genes among vancomycin low resistant Enterococccus (VLRE) isolate in Tehran hospitals. Materials and Methods: Totally 162 and 152 isolates of enterococcal species were obtained from fecal and clinical samples of hospitalized patients between March and November of 2012. The antibiotic susceptibility of the isolates and minimum inhibitory concentration (MIC) were determined according to CLSI. The presence of the van A and B resistant genes in VLREs isolates were evaluated by PCR method. Results: VLRE accounted for 162 (38.4%) and 159 (38.7%) of Enterococal isolates from clinical and fecal flora samples respectively (MIC's in the range of 16 to 64 µg/mL). VanA and vanB genotypes were detected with polymerase chain reaction (PCR) in 85 (27%) and 35 (11%) of VLRE isolates, respectively.
TURKISH JOURNAL OF MEDICAL SCIENCES, 2016
Introduction Enterococci are the natural members of the gastrointestinal tract, mouth, urethra, and vaginal flora and may result in serious nosocomial infections despite their low virulence characteristics. Enterococci are often isolated particularly from patients in intensive care units with suppressed immune systems, hematological malignancies, catheter and prosthesis existence, prolonged hospitalization duration, and usage of broad-spectrum antibiotics (1). The first vancomycin-resistant Enterococcus strain in the world was reported by Uttley et al. (2) in the UK in 1988. In Turkey, the first vancomycin-resistant Enterococcus strain was reported in a pediatric patient by Vural et al. (3) from Akdeniz University in 1998. Resistance to vancomycin develops with the vanA and vanB genes coded by plasmids and vanC, vanD, and vanG coded by chromosomes. The most common multidrug Background/aim: Enterococci play an important role in nosocomial infections. Therefore, this study investigates multidrug resistance (MDR)1 gene areas in the pathogenicity of enterococci and virulence genes in both vancomycin-sensitive enterococci (VSE) and vancomycin-resistant enterococci (VRE) strains. Materials and methods: Virulence genes and MDR genes of enterococci were investigated by polymerase chain reaction (PCR). Results: We evaluated a total of 116 isolates, 93 being VRE and 23 being VSE. In this study, 95.6% of VRE (n = 93) were Enterococcus faecium (n = 89) and 4.3% were E. faecalis (n = 4), while 17.4% of VSE (n = 23) were E. faecium (n = 4) and 82.6% were E. faecalis (n = 19). The vanA MDR1 gene was detected in all VRE isolates. Among virulence genes, esp and hyl were detected in E. faecium, an enterococcus with the highest resistance to vancomycin, and gelE was detected in E. faecalis, an enterococcus with the highest sensitivity to vancomycin. Three or more virulence genes were identified only in VSE strains. We consider that it is a significant result that VSE had more virulence genes than VRE. Only esp was seen in VRE E. faecium strains. Conclusion: This study includes experimental results on the association of virulence characteristics in VRE and VSE strains.
Journal of Antimicrobial Chemotherapy, 2002
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.
Iranian journal of public health, 2016
The aim of this study was to determine the occurrence of virulence determinants and vancomycin-resistant genes among Enterococcus faecalis and E. faecium obtained from various clinical sources. The study was performed on the 280 enterococcal isolated from clinical specimens in Hamadan hospitals, western Iran in 2012-14. Antibiotic susceptibility testing was performed using disk diffusion and Minimal Inhibitory Concentration (MIC) methods. The presence of vancomycin-resistant genes and virulence genes was investigated using PCR. Totally 280 enterococcal isolates were identified as follows: E. faecalis (62.5%), E. faecium (24%) and Enterococcus spp (13.5%). The results of antibiotic susceptibility testing showed that resistance rates to vancomycin and teicoplanin in E. faecalis and E. faecium isolates were 5% and 73%, respectively. Of Sixty vancomycin-resistant Enterococci strains, fifty-one isolates were identified as E. faecium (VREfm) and nine as E. faecalis (VREfs). Prevalence of ...