Phenotypic and genetic characterization of vancomycin-resistant enterococci from hospitalized humans and from poultry in Korea (original) (raw)
Related papers
Revista do Instituto de Medicina Tropical de São Paulo, 2008
Little is known about vancomycin-resistant enterococci in China. Thirteen pulsed-field gel electrophoresisconfirmed heterogeneous VanA-type vancomycin-resistant Enterococcus faecium (VRE) isolates were obtained from five Chinese hospitals from 2001 to 2005. The isolates were typed by multilocus sequence typing into nine different sequence types (STs), including five new STs (ST18, ST25, ST78, ST203, ST320, ST321, ST322, ST323, and ST335). Vancomycin resistance in each isolate was encoded on conjugative plasmids; two of the plasmids, pZB18 (67 kbp) and pZB22 (200 kbp), were highly conjugative and were able to transfer at high frequencies of around 10 ؊4 and 10 ؊7 per donor cell in broth mating, respectively. None of the plasmids identified in these isolates carried traA, which is usually conserved in the pMG1-like highly conjugative plasmid for E. faecium, implying that pZB18 and pZB22 were novel types of a highly conjugative plasmid in enterococci. Thirteen Tn1546-like elements encoding VanA-type VRE on the conjugative plasmids were classified into six types (types I to VI), and most of them contained both IS1216V and IS1542 insertions. The isolates carrying the type II element were predominant. The six type elements were different from that of a VanA-type Enterococcus faecalis strain isolated from Chinese chicken meat. The results suggested that the disseminations of VRE in these areas were by Tn1546-like elements being acquired by the conjugative plasmids and transferred among E. faecium strains.
Vancomycin-resistant enterococci from animal sources in Korea
Enterococci for which the minimum inhibitory concentration (MIC) of vancomycin was ≥8 mg/l were isolated from meat, feces, and raw milk samples collected in Korea from March to November 2003. Among the 243 vancomycin-resistant enterococci (VRE) that were identified the vanA vancomycin resistance gene was carried by 51 Enterococcus faecium and one Enterococcus sp., vanC1 was carried by 151 Enterococcus gallinarum, vanC2 was carried by 39 Enterococcus casseliflavus, and one Enterococcus sp. carried no van genes. Of the isolated enterococci carrying vanA, 4% were found to be highly resistant to gentamicin and 11% were resistant to ampicillin. Further genotyping of the E. faecium isolates carrying vanA using pulsed-field gel electrophoresis (PFGE) revealed extensive heterogeneity. The vancomycin resistance transferability test revealed that only two of the 52 enterococci carrying the vanA gene were able to transfer vancomycin resistance to other enterococci. The VRE were recovered from various animal sources with a particularly high prevalence of E. faecium carrying the vanA gene being found in poultry meat.
[Molecular analysis of vancomycin-resistant enterococci isolated from clinical samples]
Mikrobiyoloji bülteni, 2006
Enterococcus species are the inhabitants of gastrointestinal flora and can cause endocarditis, urinary tract infections, and bacteremia. In recent years, infections caused by vancomycin-resistant enterococci (VRE) have increased in our country. The infections caused by VRE are treated with glycopeptide antibiotics like vancomycin and teicoplanin. Although seven different resistant genes have been described in VRE, VanA is the most frequently detected one in Turkey. The aim of this study was (i) to genotype four vancomycin-resistant Enterococcus faecium strains isolated in our hospital, by using pulsed field gel electrophoresis (PFGE); and (ii) to detect the type of Van gene by using polymerase chain reaction. Three of the strains were isolated from blood cultures and one from cerebrospinal fluid of the hospitalized patients between the years 2000-2004, and identified by both conventional methods and commercial kits. By using PFGE, we detected that isolates were different according t...
Microorganisms
Food-producing animals may be a reservoir of vancomycin-resistant enterococci (VRE), potentially posing a threat to animal and public health. The aims of this study were to estimate the faecal carriage of VRE among healthy cattle (n = 362), pigs (n = 350), sheep (n = 218), and poultry (n = 102 flocks) in Switzerland, and to characterise phenotypic and genotypic traits of the isolates. VRE were isolated from caecum content of six bovine, and 12 porcine samples respectively, and from pooled faecal matter collected from 16 poultry flock samples. All isolates harboured vanA. Three different types of Tn1546-like elements carrying the vanA operon were identified. Conjugal transfer of vanA to human Enterococcus faecalis strain JH2-2 was observed for porcine isolates only. Resistance to tetracycline and erythromycin was frequent among the isolates. Our data show that VRE harbouring vanA are present in healthy food-producing animals. The vanA gene from porcine isolates was transferable to ot...
Scandinavian Journal of Infectious Diseases, 2008
Little is known about vancomycin-resistant enterococci in China. Thirteen pulsed-field gel electrophoresisconfirmed heterogeneous VanA-type vancomycin-resistant Enterococcus faecium (VRE) isolates were obtained from five Chinese hospitals from 2001 to 2005. The isolates were typed by multilocus sequence typing into nine different sequence types (STs), including five new STs (ST18, ST25, ST78, ST203, ST320, ST321, ST322, ST323, and ST335). Vancomycin resistance in each isolate was encoded on conjugative plasmids; two of the plasmids, pZB18 (67 kbp) and pZB22 (200 kbp), were highly conjugative and were able to transfer at high frequencies of around 10 ؊4 and 10 ؊7 per donor cell in broth mating, respectively. None of the plasmids identified in these isolates carried traA, which is usually conserved in the pMG1-like highly conjugative plasmid for E. faecium, implying that pZB18 and pZB22 were novel types of a highly conjugative plasmid in enterococci. Thirteen Tn1546-like elements encoding VanA-type VRE on the conjugative plasmids were classified into six types (types I to VI), and most of them contained both IS1216V and IS1542 insertions. The isolates carrying the type II element were predominant. The six type elements were different from that of a VanA-type Enterococcus faecalis strain isolated from Chinese chicken meat. The results suggested that the disseminations of VRE in these areas were by Tn1546-like elements being acquired by the conjugative plasmids and transferred among E. faecium strains.
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.
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
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.
Vancomycin-susceptible dairy and clinical enterococcal isolates carry vanA and vanB genes
International Journal of Food Microbiology, 2007
A total of 109 enterococcal isolates from dairy food products and from human and dog infections, isolated in Portugal, and 26 type and reference strains of the genus Enterococcus were screened for vancomycin resistance. MIC values, both for vancomycin and teicoplanin, were determined. The genetic relatedness of isolates carrying either vanA and/or vanB was determined using Pulsed Field Gel Electrophoresis. For vanA carrying isolates, transposon Tn1546 was partially mapped using PCR. None of the 59 dairy isolates was resistant to vancomycin. Among the 50 clinical isolates, only one, carrying vanB, behaved as resistant, with a MIC value of 256 μg/mL. The type and reference strains used were susceptible both to vancomycin and teicoplanin. vanA was found in 37% of the dairy isolates and 40% of the clinical isolates. vanB was only detected in 18% of the clinical, both human and dog, isolates. PCR partial mapping of Tn1546 revealed 23 different patterns among 42 isolates. Some patterns were shared between dairy and clinical isolates. Using Pulsed Field Gel Electrophoresis six groups of isolates were found to be genetically undistinguishable and grouping was found to be geographically and location specific/related. No genetic relatedness was found between isolates from dairy, human and veterinary sources. These results show that an incomplete and/or unfunctional Tn1546 element may explain the absence of resistant behaviour in the studied isolates, even when vanA gene is present. Moreover, the work reported shows that both clinical (human and animal) and dairy isolates have been in contact with VanA genotype of resistance and suggest that dissemination of vanA gene has been through transposable elements, like Tn1546, and not by clonal dissemination of a resistant strain. Therefore, a national strategy should be implemented to survey both vancomycin resistance and its genetic dissemination.