ISSN:
1435-4373
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The susceptibility of 1,476 US and European strains of anaerobic gram-negative bacilli to amoxicillin, amoxicillin/clavulanate, ticarcillin, ticarcillin/clavulanate, cefoxitin, imipenem and metronidazole was determined. All of theBacteroides fragilis group and 51 % of the non-Bacteroides fragilis group were β-lactamase positive. Amongst the non-Bacteroides fragilis group, β-lactamase positivity rates were higher for US strains (58 %) than for European strains (39 %). All strains were susceptible to imipenem and metronidazole. MIC90s of amoxicillin and ticarcillin for all β-lactamase negative strains were 0.5 and 2 µg/ml, respectively. The addition of clavulanate reduced the MIC90s of amoxicillin (≥ 256 µg/ml) and ticarcillin (≥ 64 µg/ml) to 16 and 8 µg/ml, respectively, for theBacteroides fragilis group, and to 4 µg/ml for both agents for the non-Bacteroides fragilis β-lactamase producing group. Twenty-nine cefoxitin-resistant strains were found, mainly in theBacteroides fragilis group, while 95 β-lactamase producing strains (predominantlyBacteroides fragilis group and fusobacteria) did not show synergy between β-lactams and clavulanate. Of the newer agents tested, meropenem and piperacillin-tazobactam were the most active (100 % of strains susceptible), followed by amoxicillin-BRL 42715 (99 % of strains susceptible); 94 to 98 % of the strains were susceptible to cefoperazone-sulbactam, tosufloxacin, tempafloxacin and clindamycin. Only 73 % of the strains were susceptible to cefotetan, compared to 91 % to cefoxitin; 88 % of the strains were susceptible to trospectomycin. Overall, all of the β-lactam/β-lactamase inhibitor combinations, imipenem, meropenem, cefoxitin, tosufloxacin, temafloxacin and clindamycin had good activity against β-lactamase producing strains, while all agents tested had good activity against β-lactamase negative strains.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01967803
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