Molecular analysis of vanA enterococci isolated from humans and animals in northeastern Italy.
A total of 53 vancomycin-resistant vanA-positive enterococci isolates from poultry farms (17 Enterococcus faecium; 8 Enterococcus durans) and from different hospitals (23 E. faecium; 5 Enterococcus faecalis) in northeastern Italy were compared on the basis of their antibiotic susceptibilities, their SmaI pulsed-field gel electrophoresis (PFGE) patterns, and the organization of their Tn1546-related elements. Ampicillin resistance was similar in both groups of isolates (52 and 60.7%, respectively), whereas human strains were more resistant to high-level gentamicin and streptomycin. A total of 52% of animal strains and 60% of human strains were resistant to tetracycline, and 56% and 46.4% to quinupristin/dalfopristin, respectively. In E. faecium and E. durans animal isolates, nine and six distinct PFGE patterns, respectively, were found: in two instances indistinguishable isolates were found from different farms. In E. faecium and E. faecalis human isolates, nine and six distinct PFGE patterns, respectively, were found; among E. faecium strains, 12 were identical or closely related and were isolates from the same hospital. Elements mediating vanA-glycopeptide resistance were characterized by PCR with primers that amplified 10 overlapping fragments of Tn1546. A total of 84.6% of animal strains and 64.2% of human strains contained elements indistinguishable from the prototype Tn1546. In addition, nine different types were identified, but none was common to animal and human strains.
Bonora
M G
MG
Department of Pathology, Section of Microbiology, University of Verona, Italy.
Boldrin
C
C
Bragagnolo
L
L
Cirelli
L
L
De Fatima
M
M
Grossato
A
A
Ligozzi
M
M
Lo Cascio
G
G
Fontana
R
R
Bordin
C
C
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D019729:Carbon-Oxygen Ligases / Q000235:genetics*; D002353:Carrier State / Q000382:microbiology; D002876:Chromosomes, Bacterial / Q000235:genetics; D013293:Enterococcus faecalis / Q000187:drug effects / Q000235:genetics*; D016984:Enterococcus faecium / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D006824:Hybridization, Genetic; D007558:Italy; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D011200:Poultry / Q000382:microbiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014640:Vancomycin / Q000494:pharmacology; D020713:Vancomycin Resistance / Q000235:genetics
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C071437:VanA ligase, Bacteria; D014640:Vancomycin; D019729:Carbon-Oxygen Ligases