We report three cases of recently named Bacteroides spp. isolates, two B. faecis isolates and one B. intestinalis isolate from clinical specimens of inpatients at a Korean tertiary-care hospital in 2011. All isolates were susceptible to piperacillin-tazobactam, imipenem, meropenem, chloramphenicol, and metronidazole.
Aged ; Anti-Bacterial Agents/pharmacology ; Bacteroides/drug effects/*isolation & purification ; Female ; Humans ; Intestines/*microbiology ; Male ; Microbial Sensitivity Tests ; Middle Aged

OBJECTIVETo extract the effective ingredient (crystal I) from effective section (saponin) of Ligustrum Lucidum Ait, identify the chemical structure of crystal I, study the effect of crystal I on P. gingivalis, B. forsythus and P. intermedia.

METHODSIsolated crystal I from saponin using the silica gel column chromatograph. Identified crystal I with IR spectra, (1)H-NMR and (13)C-NMR. Measured the minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) through micro-liquid dilution. Studied the killing curve of ursolic acid on B. forsythus and P. intermedia.

RESULTSThe crystal I was identified as ursolic acid; its MIC and MBC to P. gingivalis, B. forsythus and P. intermedia were 0.740 and 0.295 microg/L respectively. The killing curve indicated that 0.800 microg/L ursolic acid could kill P. intermedia and B. forsythus in 3 and 6 hours respectively.

CONCLUSIONUrsolic acid has obvious effect to inhibit periodontal pathogen.

Bacteroides ; drug effects ; Cell Division ; drug effects ; Ligustrum ; Magnetic Resonance Spectroscopy ; methods ; Microbial Sensitivity Tests ; Periodontium ; microbiology ; Plant Extracts ; isolation & purification ; pharmacology ; Porphyromonas gingivalis ; drug effects ; Prevotella intermedia ; drug effects ; Triterpenes ; pharmacology

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.
Anti-Bacterial Agents/pharmacology ; Bacteroides/classification/*drug effects/isolation & purification ; Bacteroides fragilis/drug effects/isolation & purification ; Cefoxitin/pharmacology ; Chloramphenicol/pharmacology ; *Drug Resistance, Multiple, Bacterial ; Humans ; Imipenem/pharmacology ; Metronidazole/pharmacology ; Microbial Sensitivity Tests ; Penicillanic Acid/analogs & derivatives/pharmacology ; Piperacillin/pharmacology ; Republic of Korea

BACKGROUND: Periodic monitoring of antimicrobial resistance trends of clinically important anaerobic bacteria such as Bacteroides fragilis group organisms is required. We determined the antimicrobial susceptibilities of clinical isolates of B. fragilis group organisms recovered from 2009 to 2012 in a tertiary-care hospital in Korea. METHODS: A total of 180 nonduplicate clinical isolates of B. fragilis group organisms were collected in a tertiary care hospital. The species were identified by conventional methods: the ATB 32A rapid identification system (bioMerieux, France) and the Vitek MS matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (bioMerieux). Antimicrobial susceptibility was determined by the CLSI agar dilution method. RESULTS: Imipenem and meropenem resistance rates were 0-6% for B. fragilis group isolates. The rate of resistance to piperacillin-tazobactam was 2% for B. fragilis and 0% for other Bacteroides species, but 17% for B. thetaiotaomicron isolates. High resistance rates to piperacillin (72% and 69%), cefotetan (89% and 58%), and clindamycin (83% and 69%) were observed for B. thetaiotaomicron and other Bacteroides spp. The moxifloxacin resistance rate was 27% for other Bacteroides spp. The MIC50 and MIC90 of tigecycline were 2-4 microg/mL and 8-16 microg/mL, respectively. No isolates were resistant to chloramphenicol or metronidazole. CONCLUSIONS: Imipenem, meropenem, chloramphenicol, and metronidazole remain active against B. fragilis group isolates. Moxifloxacin and tigecycline resistance rates are 2-27% and 8-15% for B. fragilis group isolates, respectively.
Anti-Infective Agents/*pharmacology ; Bacteroides Infections/*microbiology/pathology ; Bacteroides fragilis/*drug effects/isolation & purification ; Drug Resistance, Multiple, Bacterial ; Humans ; Imipenem/pharmacology ; Inhibitory Concentration 50 ; Microbial Sensitivity Tests ; Penicillanic Acid/analogs & derivatives/pharmacology ; Piperacillin/pharmacology ; Republic of Korea ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Tertiary Care Centers ; Thienamycins/pharmacology