Gram-positive anaerobic cocci are resistant to penicillin and clindamycin

Abstract number: P1724

Nord C.E.

Objectives: Gram-positive anaerobic cocci (GPAC) are a heterogeneous group of microorganisms. GPAC are involved in one-quarter of all anaerobic isolates from human clinical infections. The prevalence of GPAC as pathogens is increasing and information regarding their antimicrobial susceptibilities is relatively limited compared with that of other anaerobic species. The aim of this study was to examine the current status of antimicrobial resistance in clinical isolates of GPAC in Europe.

Methods: Collaborators in each participating country (Austria, Croatia, Czech Republic, Denmark, Finland, France, Great Britain, Greece, Hungary and Sweden) collected consecutive clinical isolates of GPAC. The isolates were identified by Gram staining, biochemical tests and gas–liquid chromatography. Minimum inhibitory concentrations of penicillin, clindamycin, metronidazole, vancomycin and linezolid were determined by the agar dilution method according to the Clinical and Laboratory Standards Institute. Production of b-lactamase was determined by the nitrocefin test.

Results: 299 strains were identified as GPAC and 23 isolates as other species. Most isolates were collected in Sweden (22%), Finland (19%) and Great Britain (18%). The majority of isolates were identified as Finegoldia magna (111), Parvimonas micra (53), Peptoniphilus harei (44), Anaerococcus vaginalis (21) and P. anaerobius (20). Nineteen isolates were identified as Peptostreptococcus sp. The remaining isolates were identified as Peptoniphilus asaccharolyticus (8), Peptoniphilus ivorii (5), Peptoniphilus indolicus (8), Peptoniphilus lacrimalis (5), Anaerococcus octavius (1), Anaerococcus prevotii (2), Anaerococcus tetradius (1) and Anaerococcus lactolyticus (1). All isolates were susceptible to metronidazole, vancomycin and linezolid. A total of 21 isolates were resistant to penicillin and/or clindamycin. The majority of resistant strains were collected in Great Britain. Eight of the isolates were identified as F. magna, of which four were resistant to clindamycin, three to both penicillin and clindamycin and one isolate to penicillin. No isolates produced b-lactamases. The origins of resistant isolates were blood, abscesses and soft tissue infections.

Conclusion: Antimicrobial susceptibility testing of anaerobic cocci in patients with severe infections as well as continuous surveillance of antimicrobial susceptibility in GPAC seem highly justified.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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