The number of 168 retail meat samples (72 poultry, 61 swine, 35 bovine) in Aomori prefecture were examined for contamination by Campylobacter and for evaluation of the antimicrobial susceptibility of isolates. C. jejuni was isolated from 17 poultry samples (3 breast strips, 2 wing, 3 skin, 4 liver and 5 leg), 2 swine samples (1 bowel and 1 seasoned bowel), and 1 bovine sample (1 bowel). C. coli was isolated from 10 swine samples (6 bowel and 4 seasoned bowel) and 2 bovine samples (1 bowel and 1 seasoned bowel). C. lari was isolated from 1 swine sample (1 seasoned bowel). No Campylobacter were detected from breast in poultry, lean, tongue, mince, womb and liver in swine and lean in bovine. The finding suggest that C. jejuni is associated with poultry meat and C. coli is associated with the bowel in swine and bovine. Fifteen strains of C. jejuni and 14 strains of C. coli were tested for antimicrobial susceptibility test. All tested antimicrobials were effective against 9 strains of C. jejuni and 3 strains of C. coli. All strains were found to be susceptible to fosfomycin; erythromycin resistance was observed in 3 strains of C. coli, tetracycline resistance in 2 strains of C. jejuni and 8 strains of C. coli, and ciprofloxacin and ofloxacin resistance in 6 strains of C. jejuni and 4 strains of C. coli. The findings suggested that antimicrobial susceptibility of Campylobacter differs among species.
In August 2016, a food-poisoning outbreak occurred across several nursing homes in Japan, which was caused by enterohemorrhagic Escherichia coli (EHEC) O157. The cucumbers added in perillas were speculated as the food causing the infection, due to the inefficient sterilization of cucumbers at these facilities. The present study aimed to investigate the bactericidal effects of sodium hypochlorite solution (NaClO) and hot water (80℃) on cucumbers attached with two E. coli strains: EH5487 (EHEC) and EC3207 (non- EHEC). The number of EC3207 did not reduce when treated by NaClO at 40 ppm or 200 ppm; whereas, the treatment of 2,000 ppm NaClO could significantly reduce the number of EC3207. Considering the bacterial count responsible for EHEC infection to be caused (10–100 CFU), the effect was insufficient. On the contrary, the number of EC3207 and EH5487 could be reduced to less than detective limit (1.0 log CFU/g) when treated with hot water. These results lead to the conclusion that the treatment with hot water at 80℃ is a useful sterilization method for E. coli including EHEC.