Application of DNA probes for rRNA and vanA genes to investigation of a nosocomial cluster of vancomycin-resistant enterococci (original) (raw)
Related papers
PCR fragment length polymorphism analysis of vancomycin-resistant Enterococcus faecium
Journal of clinical microbiology, 2000
In this study, the glycopeptide resistance element, Tn1546, in 124 VanA Enterococcus faecium clinical isolates from 13 Michigan hospitals was evaluated using PCR fragment length polymorphism. There were 26 pulsed-field gel electrophoresis (PFGE) types, which consisted of epidemiologically related and unrelated isolates from separate patients (1992 to 1996). Previously published oligonucleotides specific for regions in the vanA gene cluster of Tn1546 were used to amplify vanRS, vanSH, vanHAX, vanXY, and vanYZ. The glycopeptide resistance element, Tn1546, of E. faecium 228 was used as the basis of comparison for all the isolates in this study. Five PCR fragment length patterns were found, as follows. (i) PCR amplicons were the same size as those of EF228 for all genes in the vanA cluster in 19.4% of isolates. (ii) The PCR amplicon for vanSH was larger than that of EF228 (3.7 versus 2.3 kb) due to an insertion between the vanS and vanH genes (79.2% of isolates). (iii) One isolate in a ...
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.
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.
Microbial Drug Resistance, 1996
A total of 182 vancomycin-resistant Enterococcus faecium and 6 Enterococcus faecalis inpatient isolates recovered during a 2-year period (1990)(1991)(1992) in a New York City hospital were analyzed by molecular fingerprinting techniques, pulsed-field gel electrophoresis (PFGE), of chromosomal Smal digests combined with Southern hybridization using vanA and vanß2-specific DNA probes. Of the 180 isolates hybridizing with these probes, 153 carried the vanA and 27 the vanB gene. As many as 21 different PFGE types and a total of 54 subtypes were identified among the isolates, and the size of vanA and va/tß-hybridizing DNA fragments also showed a wide range of sizes, from about 37 to over 280 kb (in vanA) or 140 kb (in vanB), suggesting extensive recombination, including chromosomal integration, of the resistance genes in the isolates. Close to onethird, 46, of the 148 isolates from 1992 belonged to two closely related PFGE subtype variants, each of which carried a 48 kb vanA hybridizing DNA fragment. Spread of this clone appears to be mainly responsible for the substantial increase in the prevalence of vancomycin-resistant E. faecium in early 1992.
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.
[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...
J Clin Microbiol, 1991
Vancomycin-resistant enterococci are now found with increasing frequency. Up to now, epidemiological studies of enterococci have been limited by the lack of convenient and accessible methods for comparing strains. In this study, we report an epidemiological investigation on 16 nosocomial vancomycin-resistant Enterococcus faecium strains isolated from 15 patients in four different wards of a children's hospital over a period of 17 months. Analysis of restriction fragment length polymorphism (RFLP) of total DNA and of ribosomal DNA regions (ribotyping) was used as a typing approach. Each strain produced a different total DNA RFLP pattern after HindIll and PvuII digestion, except for two strains that were isolated from a single patient and that gave indistinguishable patterns. In our system, ribotyping was less discriminative than RFLP of total DNA. This approach, therefore, shows the genetic unrelatedness of the nosocomial strains studied and excludes patient-to-patient strain transmission either in the same ward or between wards.
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