Assessment of susceptibility of strictly anaerobic bacteria originated from different sources to fluoroquinolones and other antimicrobial drugs

INTRODUCTION: During the past 20 years, several studies at a national level in different countries followed resistance trends for Bacteroides sp. and Clostridium difficile. This study analysed antimicrobial susceptibility 73 anaerobic bacteria strains of Bacteroides fragilis group (BFG) and C. difficile to fluoroquinolones and other antimicrobial drugs. METHODS: The strictly anaerobes strains isolated in different hospitals were sent to the Department of Medical Microbiology, Medical Uniwersity of Warsaw, where species determination was carried out with the API20 ANA (bioMerieux SA, Marcy-l'Etoile, France) system. Susceptibility to antimicrobials was determined using E-test. RESULTS: The rates of high resistance to ciprofloxacin and moxifloxacin of BFG was respectively 84% and 31% and among of C. difficile strains respectively 92% and 36%). The percentage of BFG strains resistant to erythromycin and clindamycin were respectively 84% and 46%. The percentage of C. difficile strains resistant to erythromycin and clindamycin was 52%. Reduced level of susceptibility of BFG strains to amoxicillin/clavulanic acid (8%) was confirmed. Resistance to cefoxitin was 16% of BFG strains. All tested strains as well as BFG and C. difficile were susceptible to metronidazole. Was observed reduced leve (EUCAST) of susceptibility of C. difficile strains to vancomycin (13%). CONCLUSIONS. Increasing resistance to various antimicrobial agents is a significant problem in Poland. This demonstrate the need to continue with antibiotic resistance testing and surveys in anaerobic bacteria.