OBJECTIVETo isolate and culture the predominant anaerobes from the periodontal abscesses, and to test the antibiotic susceptibility and drug resistant genes of the strains.

METHODSThe isolated strains were identified by both API20A biochemical method and polymerase chain reaction (PCR) method. The antibiotic susceptibility test was performed by agar dilution method. The resistant genes of the drug-resistant strains obtained were screened by PCR.

RESULTSThe anaerobes were detected in 48% (28/58) of the samples and Prevotella melaninogenica (Pm) was mostly identified in 43% (12/28). API20A biochemical method had 82% (23/28) agreement with the 16SrRNA method in identification rate. Anaerobes were resistant to metronidazole, clindamycin and cefmetazole. The erythromycin-resistant methylase genes F (ermF) gene was detected in three of eight clindamycin resistant strains. None of them was found coded on bacterial plasmids. However, no metronidazole resistant gene was detected on drug resistant strains.

CONCLUSIONSPm was the predominant species dectected in the periodontal abscess of the patients. The antibiotic agents should be used based on the genotypes and general condition of the patients.

Adult ; Anti-Bacterial Agents ; pharmacology ; Bacteria, Anaerobic ; isolation & purification ; Cefmetazole ; pharmacology ; Clindamycin ; pharmacology ; Drug Resistance, Bacterial ; genetics ; Erythromycin ; pharmacology ; Female ; Genes, Bacterial ; Humans ; Male ; Metronidazole ; pharmacology ; Microbial Sensitivity Tests ; Middle Aged ; Periodontal Abscess ; microbiology ; Prevotella ; isolation & purification

BACKGROUND: By conventional methods, the identification of anaerobic bacteria is more time consuming and requires more expertise than the identification of aerobic bacteria. Although the matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) systems are relatively less studied, they have been reported to be a promising method for the identification of anaerobes. We evaluated the performance of the VITEK MS in vitro diagnostic (IVD; 1.1 database; bioMerieux, France) in the identification of anaerobes. METHODS: We used 274 anaerobic bacteria isolated from various clinical specimens. The results for the identification of the bacteria by VITEK MS were compared to those obtained by phenotypic methods and 16S rRNA gene sequencing. RESULTS: Among the 249 isolates included in the IVD database, the VITEK MS correctly identified 209 (83.9%) isolates to the species level and an additional 18 (7.2%) at the genus level. In particular, the VITEK MS correctly identified clinically relevant and frequently isolated anaerobic bacteria to the species level. The remaining 22 isolates (8.8%) were either not identified or misidentified. The VITEK MS could not identify the 25 isolates absent from the IVD database to the species level. CONCLUSIONS: The VITEK MS showed reliable identifications for clinically relevant anaerobic bacteria.
Bacteria, Anaerobic/*genetics/isolation & purification ; Bacterial Typing Techniques/*instrumentation/*methods ; Body Fluids/microbiology ; Databases, Genetic ; Humans ; RNA, Ribosomal, 16S/*analysis/metabolism ; Sequence Analysis, DNA ; *Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

No abstract available.
Aged ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Cefotaxime/analogs & derivatives/therapeutic use ; Cholangiopancreatography, Endoscopic Retrograde ; Gallstones/surgery ; Gram-Negative Anaerobic Bacteria/drug effects/genetics/*isolation & purification ; Gram-Negative Bacterial Infections/*diagnosis/drug therapy/microbiology ; Humans ; Male ; Metronidazole/therapeutic use ; Microbial Sensitivity Tests ; RNA, Ribosomal, 16S/chemistry/genetics/metabolism ; Sequence Analysis, DNA ; Tomography, X-Ray Computed