β-lactamase-mediated β-lactam resistance in campylobacter species : prevalence of Cj0299 (blaOXA-61) and evidence for a novel β-lactamase in C. jejuni
Griggs, Deborah, Peake, L., Johnson, M. M., Ghori, S., Mott, A. and Piddock, L. J. V.. (2009) β-lactamase-mediated β-lactam resistance in campylobacter species : prevalence of Cj0299 (blaOXA-61) and evidence for a novel β-lactamase in C. jejuni. Antimicrobial Agents and Chemotherapy, Vol.53 (No.8). pp. 3357-3364. ISSN 0066-4804Full text not available from this repository.
Official URL: http://dx.doi.org/10.1128/AAC.01655-08
Fifty-two percent of 1,288 poultry isolates of campylobacters were ampicillin resistant, and resistance was more common among Campylobacter coli isolates (67.4%) than among Campylobacter jejuni isolates (47.5%). Production of β-lactamase was typically associated with resistance to ampicillin, amoxicillin (amoxicilline), penicillin, and ticarcillin. Regardless of β-lactamase production, all isolates were resistant to piperacillin (MICs ≥ 256 μg/ml), and most were resistant to carbenicillin, cloxacillin, and cephalosporins. Of all ampicillin-resistant campylobacters tested, 91% (347/380) carried the blaOXA-61 gene, and 77% (136/175) of those tested with nitrocefin produced a β-lactamase, presumably OXA-61. The isoelectric point (pI) of OXA-61 was 8.7, and the molecular mass was 31.0 kDa. Insertional inactivation of blaOXA-61 in C. jejuni NCTC 11168 and two ampicillin-resistant isolates resulted in increased susceptibility to ampicillin, co-amoxiclav (amoxicillin and clavulanic acid), penicillin, carbenicillin, oxacillin, and piperacillin, but the effects on MICs of cephalosporins and imipenem were negligible. Some C. jejuni isolates that lacked blaOXA-61 produced a β-lactamase, CjBla2, with a pI of 9.2 and molecular mass of 32.4 kDa. Mass spectrometry confirmed that the most prevalent β-lactamase was the product of blaOXA-61, but CjBla2 was not identified. OXA-61 is prevalent among Campylobacter spp. of veterinary origin and is similar to the β-lactamase previously reported in human isolates. Production of OXA-61 was associated with resistance to penams but not cephalosporins. Co-amoxiclav remained active against all isolates tested.
|Item Type:||Journal Article|
|Divisions:||Faculty of Medicine > Warwick Medical School|
|Journal or Publication Title:||Antimicrobial Agents and Chemotherapy|
|Publisher:||American Society for Microbiology|
|Official Date:||August 2009|
|Page Range:||pp. 3357-3364|
|Access rights to Published version:||Restricted or Subscription Access|
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