Role of transposon Tn5482 in the epidemiology of vancomycin-resistant Enterococcus faecium in the Pediatric Oncology Unit of a New York City Hospital Journal Article


Authors: De Lencastre, H.; Brown, A. E.; Chung, M.; Armstrong, D.; Tomasz, A.
Article Title: Role of transposon Tn5482 in the epidemiology of vancomycin-resistant Enterococcus faecium in the Pediatric Oncology Unit of a New York City Hospital
Abstract: During a 36-month period between 1993 and 1995 in the Pediatric Oncology Unit of Memorial Sloan Kettering Cancer Center, 74 patients experienced episodes of infection or colonization caused by vancomycin-resistant enterococci (VRE). Characterization of the 74 bacterial isolates by microbiological and molecular techniques (pulsed-field gel electrophoresis and hybridization with DNA probes specific for the vanA and vanB genes and for IS1251) identified 73 Enterococcus faecium and one Enterococcus faecalis (vanB) among the primary VRE isolates. Most (69/73) of the E. faecium isolates carried vanA and four isolates, the vanB gene complex. The overwhelming majority (67/69) of the vanA-positive isolates also gave hybridization signal for IS1251, indicating the presence of the newly described conjugative transposon Tn5482. No hybridization with IS1251 was obtained with the four vanB-carrying isolates. About 30% of the vanA-positive strains (23/69) were represented by PFGE subtype variants of a single clone, most isolates of which were recovered during a 4-month period between April to June of 1994. The larger portion of the vanA-carrying VRE represented by close to 70% of the isolates (46/69) belonged to as many as 37 different clonal types, indicating tremendous genetic diversity. Among 67 of the 69 vanA-carrying isolates, the localization of the Tn5482-associated vanA gene complex could be unequivocally identified either on the chromosome (40/69) or in plasmids (27/69). Transconjugants recovered from filter mating experiments using either a chromosomally located or plasmid-borne vanA donor strain and a single vancomycin-susceptible strain of either E. faecium or E. faecalis were analyzed by molecular typing techniques. Seven out of 10 independent transconjugants recovered from the same cross showed extensive differences in PFGE pattern and also in the localization of the vanA hybridizing DNA fragment transferred from the common VRE donor with chromosomally located vanA. The observations suggest that the extensive genetic diversity observed among the clinical isolates of VRE may be generated during conjugation between vancomycin-resistant and -susceptible enterococcal isolates. The observations also suggest that the epidemic spread of VRE in the United States may be linked to the frequent presence of Tn5482 among the American isolates.
Keywords: child; controlled study; major clinical study; nonhuman; united states; neoplasms; childhood cancer; antibiotic resistance; anti-bacterial agents; medical oncology; new york city; bacterium isolate; nucleic acid hybridization; hospital infection; gram-positive bacterial infections; vancomycin; bacterial infection; hospitals, urban; cross infection; transposon; pediatrics; chromosomal localization; pulsed field gel electrophoresis; electrophoresis, gel, pulsed-field; enterococcus faecium; dna fragmentation; dna transposable elements; drug resistance, microbial; dna hybridization; dna probes; humans; human; priority journal; article; hospital units; bacterium conjugation; conjugation, genetic
Journal Title: Microbial Drug Resistance
Volume: 5
Issue: 2
ISSN: 1076-6294
Publisher: Mary Ann Liebert, Inc  
Date Published: 1999-01-01
Start Page: 113
End Page: 129
Language: English
PUBMED: 10432272
PROVIDER: scopus
DOI: 10.1089/mdr.1999.5.113
DOI/URL:
Notes: Article -- Export Date: 16 August 2016 -- Source: Scopus
Altmetric
Citation Impact
BMJ Impact Analytics
MSK Authors
  1. Arthur E Brown
    76 Brown
  2. Donald Armstrong
    240 Armstrong