Phylogenetic groups and cephalosporin resistance genes of Escherichia coli from diseased food-producing animals in Japan |
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| Authors: | Tetsuo Asai Kaori Masani Chizuru Sato Mototaka Hiki Masaru Usui Kotaro Baba Manao Ozawa Kazuki Harada Hiroshi Aoki Takuo Sawada |
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| Institution: | 1.National Veterinary Assay Laboratory, Ministry of Agriculture, Forestry and Fisheries, 1-15-1 Tokura, Kokubunji, Tokyo 185-8511;2.Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino, Tokyo 180-8601, Japan |
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| Abstract: | A total of 318 Escherichia coli isolates obtained from different food-producing animals affected with colibacillosis between 2001 and 2006 were subjected to phylogenetic analysis: 72 bovine isolates, 89 poultry isolates and 157 porcine isolates. Overall, the phylogenetic group A was predominant in isolates from cattle (36/72, 50%) and pigs (101/157, 64.3%) whereas groups A (44/89, 49.4%) and D (40/89, 44.9%) were predominant in isolates from poultry. In addition, group B2 was not found among diseased food-producing animals except for a poultry isolate. Thus, the phylogenetic group distribution of E. coli from diseased animals was different by animal species. Among the 318 isolates, cefazolin resistance (minimum inhibitory concentrations: ≥32 μg/ml) was found in six bovine isolates, 29 poultry isolates and three porcine isolates. Of them, 11 isolates (nine from poultry and two from cattle) produced extended spectrum β-lactamase (ESBL). The two bovine isolates produced blaCTX-M-2, while the nine poultry isolates produced blaCTX-M-25 (4), blaSHV-2 (3), blaCTX-M-15 (1) and blaCTX-M-2 (1). Thus, our results showed that several types of ESBL were identified and three types of β-lactamase (SHV-2, CTX-M-25 and CTX-M-15) were observed for the first time in E. coli from diseased animals in Japan. |
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| Keywords: | Escherichia coli food-producing animals cephalosporin resistance extended spectrum β -lactamase AmpC β -lactamase phylogenetic grouping |
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