title: Antimicrobial resistance and prevalence of resistance genes of obligate anaerobes isolated from periodontal abscesses.
abstract: BACKGROUND
  This study attempts to determine the antimicrobial resistance profiles of obligate anaerobic bacteria that were isolated from a periodontal abscess and to evaluate the prevalence of resistance genes in these bacteria.
  
  
  METHODS
  Forty-one periodontal abscess samples were cultivated on selective and non-selective culture media to isolate the oral anaerobes. Their antibiotic susceptibilities to clindamycin, doxycycline, amoxicillin, imipenem, cefradine, cefixime, roxithromycin, and metronidazole were determined using the agar dilution method, and polymerase chain reaction assays were performed to detect the presence of the ermF, tetQ, nim, and cfxA drug resistance genes.
  
  
  RESULTS
  A total of 60 different bacterial colonies was isolated and identified. All of the isolates were sensitive to imipenem. Of the strains, 6.7%, 13.3%, 16.7%, and 25% were resistant to doxycycline, metronidazole, cefixime, and amoxicillin, respectively. The resistance rate for both clindamycin and roxithromycin was 31.7%. Approximately 60.7% of the strains had the ermF gene, and 53.3% of the amoxicillin-resistant strains were found to have the cfxA gene. Two nim genes that were found in eight metronidazole-resistant strains were identified as nimB.
  
  
  CONCLUSIONS
  In the present study, the Prevotella species are the most frequently isolated obligate anaerobes from periodontal abscesses. The current results show their alarmingly high resistance rate against clindamycin and roxithromycin; thus, the use of these antibiotics is unacceptable for the empirical therapy of periodontal abscesses. A brief prevalence of four resistance genes in the anaerobic bacteria that were isolated was also demonstrated.
authors: Department of Stomatology, Hua Shan Hospital, Fudan University, Yangpu, Shanghai, China.
authors: Yi
authors: Y
authors: Xie
authors: Jiazhen
authors: J
authors: Chen
authors: Junlin
authors: J
authors: He
authors: Xinyu
authors: X
authors: Miao
authors: Meng
authors: M
authors: Xu
authors: Xingwen
authors: X
authors: Wu
authors: Beiyun
authors: B
authors: Xu
authors: Liying
authors: L
authors: Yu
authors: Wenhong
authors: W
authors: Zhang
mesh_terms: D000658:Amoxicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001421:Bacteria, Anaerobic / Q000145:classification / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics; D001431:Bacteriological Techniques; D016866:Bacteroidaceae Infections / Q000382:microbiology; D020682:Cefixime / Q000494:pharmacology; D002515:Cephradine / Q000494:pharmacology; D002981:Clindamycin / Q000494:pharmacology; D004318:Doxycycline / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005260:Female; D005798:Genes, Bacterial / Q000235:genetics*; D006801:Humans; D015378:Imipenem / Q000494:pharmacology; D008297:Male; D008780:Methyltransferases / Q000235:genetics; D008795:Metronidazole / Q000494:pharmacology; D008875:Middle Aged; D010508:Periodontal Abscess / Q000382:microbiology*; D018720:Prevotella / Q000145:classification / Q000235:genetics; D015575:Roxithromycin / Q000494:pharmacology; D013753:Tetracycline Resistance / Q000235:genetics; D018440:beta-Lactam Resistance / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D008795:Metronidazole; D015575:Roxithromycin; D002981:Clindamycin; D015378:Imipenem; D000658:Amoxicillin; D020682:Cefixime; D008780:Methyltransferases; D001618:beta-Lactamases; D002515:Cephradine; D004318:Doxycycline