Resistance trends of Bacteroides fragilis group over an 8-year period, 1997-2004, in Korea.
BACKGROUND
Bacteroides fragilis group organisms are the most frequently isolated anaerobes in human infections. Increasing resistance to various antimicrobial agents is a significant problem in choosing appropriate antimicrobial agents to treat anaerobic infections. Periodic monitoring of the regional resistance trends of B. fragilis group isolates is needed.


METHODS
A total of 466 nonduplicate clinical isolates of B. fragilis group organisms (276 B. fragilis, 106 Bacteroides thetaiotaomicron, and 84 other B. fragilis group organisms) were collected during the 8-yr period from 1997 to 2004 in a Korean university hospital. Minimum inhibitory concentrations to various antimicrobial agents were determined by the CLSI agar dilution method.


RESULTS
Eight isolates were resistant to imipenem. Additionally, the resistance rates to cefotetan were decreased in B. thetaiotaomicron, while those for clindamycin were significantly increased compared to the rates found in previous studies. Depending on species, resistance rates were 1-4% for imipenem, 1-6% for piperacillin-tazobactam, 4-11% for cefoxitin, 33-49% for piperacillin, 14-60% for cefotetan, and 51-76% for clindamycin. No isolates were resistant to chloramphenicol or metronidazole.


CONCLUSIONS
Piperacillin-tazobactam, cefoxitin, imipenem, chloramphenicol, and metronidazole are still active against B. fragilis group isolates, while clindamycin no longer has a value as an empirical therapeutic agent in Korea. Furthermore, this study identified the first imipenem-resistant B. fragilis group isolates in Korea.
Roh
Kyoung Ho
KH
Department of Laboratory Medicine, Korea University College of Medicine, Seoul, Korea.
Kim
Sinyoung
S
Kim
Chang-Ki
CK
Yum
Jong Hwa
JH
Kim
Myung Sook
MS
Yong
Dongeun
D
Lee
Kyungwon
K
Kim
June Myung
JM
Chong
Yunsop
Y
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001439:Bacteroides / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D001441:Bacteroides fragilis / Q000187:drug effects / Q000302:isolation & purification; D002440:Cefoxitin / Q000494:pharmacology; D002701:Chloramphenicol / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial; D006801:Humans; D015378:Imipenem / Q000494:pharmacology; D008795:Metronidazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D010397:Penicillanic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D010878:Piperacillin / Q000494:pharmacology; D000077725:Piperacillin, Tazobactam Drug Combination; D056910:Republic of Korea
D000900:Anti-Bacterial Agents; D008795:Metronidazole; D000077725:Piperacillin, Tazobactam Drug Combination; D002701:Chloramphenicol; D002440:Cefoxitin; D015378:Imipenem; D010397:Penicillanic Acid; D010878:Piperacillin