Antimicrobial susceptibility of anaerobic bacteria in New Zealand: 1999–2003

• Published in: Journal of antimicrobial chemotherapy Vol. 57; no. 5; pp. 992 - 998
• Main Authors: Roberts, Sally A., Shore, Keith P., Paviour, Susan D., Holland, David, Morris, Arthur J.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.05.2006; Oxford Publishing Limited (England)
• Subjects: anaerobes; Anti-Bacterial Agents - pharmacology; Antibiotics. Antiinfectious agents. Antiparasitic agents; Bacteria, Anaerobic - drug effects; Bacteria, Anaerobic - isolation & purification; Bacterial Infections - microbiology; Bacteroides fragilis; Biological and medical sciences; Clostridium perfringens; Clostridium tertium; Drug Resistance, Multiple, Bacterial - drug effects; Eubacterium; Fusobacterium; Humans; Medical sciences; Microbial Sensitivity Tests; New Zealand; Peptostreptococcus anaerobius; Pharmacology. Drug treatments; Prevotella; Propionibacterium; Propionibacterium acnes; susceptibility patterns; susceptibility trends; Veillonella; New Zealand; Oceania; susceptibility trends; Anaerobic bacteria; Sensitivity resistance; Drug susceptibility test; Anaerobe; susceptibility patterns; Antibacterial agent; anaerobes
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/dkl052

Objectives: Routine susceptibility testing of all anaerobic organisms is not advocated, but it is useful for laboratories to test periodically for anaerobic organisms and provide local susceptibility data to guide therapy. This study reports the national trend of antibiotic susceptibility of clinically significant anaerobes in New Zealand. Methods: Clinical isolates were tested using standardized methods against a range of antibiotics commonly used to treat anaerobic infections. Susceptibility was determined using NCCLS criteria. The change in susceptibility trends between this study and earlier studies was measured by comparing the geometric mean of the MIC. Results: A total of 364 anaerobes were tested. Penicillin had poor activity against Bacteroides spp., Prevotella spp., Eubacterium spp., Clostridium tertium and Veillonella spp. In general, Fusobacterium spp., Bacteroides ureolyticus, Propionibacterium spp., Clostridium perfringens and anaerobic streptococci isolates, with the exception of Peptostreptococcus anaerobius, were penicillin susceptible. Amoxicillin/clavulanate showed good activity against most anaerobes, but resistance was seen with Bacteroides fragilis group and P. anaerobius isolates. Cefoxitin was more active than cefotetan, particularly against non-B. fragilis species, Eubacterium spp. and P. anaerobius. Meropenem and imipenem showed good activity against all anaerobes, with only 2 and 4% of Bacteroides spp., respectively, showing resistance. With the exception of Propionibacterium acnes isolates, which are predictably resistant, metronidazole was active against all anaerobes tested. There has been little change in susceptibility since 1997. Conclusions: Metronidazole, cefoxitin, piperacillin/tazobactam and amoxicillin/clavulanate remain good empirical choices when anaerobes are expected in our setting. No clinically relevant changes in susceptibility over time were found.