Genetic relatedness of Enterococcus faecalis isolates with high-level gentamicin resistance from patients with bacteraemia in the south east of Sweden 1994-2001.
High-level gentamicin resistant (HLGR) enterococci (Enterococcus faecalis and Enterococcus faecium) have become a substantial nosocomial problem in many countries. In this study, we investigated the prevalence of HLGR enterococci and their genetic relatedness in blood culture isolates from patients with bacteraemia admitted to the 3 hospitals in Ostergötland, a county in the south east of Sweden, during 1994-2001. 36 of 250 E. faecalis (14%,) and 4 of 106 E. faecium isolates (4%) were shown by PCR to carry the aac(6')-Ie-aph(2")-Ia aminoglycoside modifying gene and these isolates were also classified as HLGR enterococci by the gentamicin antibiotic disk diffusion method. A majority of HLGR E. faecalis isolates (83%) belonged to the same cluster of genetically related isolates, according to the pulsed-field gel electrophoresis (PFGE) patterns, whereas all 4 HLGR E. faecium isolates had unique PFGE patterns. In conclusion, our study showed that in contrast to studies from many other countries, the presence of HLGR enterococci was more common in E. faecalis than in E. faecium and appeared the first time in 1996 and 1999, respectively. Bacteraemia with HLGR enterococci in Ostergötland was mainly due to the spread of a cluster of related E. faecalis strains.
Division of Clinical Microbiology, Department of Molecular and Clinical Medicine, Faculty of Health Sciences, University Hospital, SE-581 85 Linköping, Sweden. baharak.saeedi@lio.se
Baharak
B
Saeedi
Anita
A
Hällgren
Barbro
B
Isaksson
Jon
J
Jonasson
Lennart E
LE
Nilsson
Håkan
H
Hanberger
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology; D001426:Bacterial Proteins / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D013293:Enterococcus faecalis / Q000145:classification / Q000187:drug effects / Q000235:genetics*; D016984:Enterococcus faecium / Q000145:classification / Q000187:drug effects / Q000235:genetics; D005839:Gentamicins / Q000494:pharmacology*; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D015995:Prevalence; D013548:Sweden / Q000453:epidemiology
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D005839:Gentamicins