Midori Hiroi

Anaplasma phagocytophilum-infected ticks, Japan.

We report Anaplasma phagocytophilum infection of Ixodes persulcatus and I. ovatus ticks in Japan. Unique p44/msp2 paralogs (and/or 16S rRNA genes) were detected in tick tissues, salivary glands, and spleens of experimentally infected mice. These findings indicate the public health threat of anaplasmosis in Japan.

Molecular Identification of Ehrlichia Species and 'Candidatus Neoehrlichia mikurensis' from Ticks and Wild Rodents in Shizuoka and Nagano Prefectures, Japan

A total of 293 ticks and 111 wild rodents that were collected in Shizuoka and Nagano Prefectures, Japan, were examined for infection of Ehrlichia species and ‘Candidatus Neoehrlichia mikurensis.’ The 16S rDNA or the omp‐1 gene of these bacterial DNAs were detected from the spleens of tick‐inoculated mice (5 positive/total 29 mice) or from the spleens of wild rodents (25 positive/total 111 rodents) by PCR amplification. Sequencing of the 16S rDNA revealed Ehrlichia spp. from the 5 tick‐inoculated mice and 8 wild rodents, and ‘Candidatus N. mikurensis’ from 17 wild rodents. The data suggest the presence of additional genetic variants, and potential vectors and/or reservoirs for these bacteria in central Japan.

Antibiotic resistance in bacterial pathogens from retail raw meats and food-producing animals in Japan.

To determine the prevalence and antimicrobial susceptibility profiles of Campylobacter, Salmonella, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), and vancomycin-resistant enterococci (VRE) in food-producing animals and retail raw meats in Japan, raw meat samples as well as food-producing animal feces, cutaneous swabs, and nasal swabs collected from 2004 to 2006 were analyzed. Isolation rates of Campylobacter jejuni and Campylobacter coli, Salmonella, and S. aureus were 34.6% (363 of 1,050), 2.7% (28 of 1,050), and 32.8% (238 of 725), respectively. MRSA was isolated from 3% (9 of 300) of meat samples. No VRE were isolated in this study. Antibiotic resistance in C. coli was higher than that in C. jejuni. Three C. jejuni isolates from a patient with diarrhea in a hospital of Shizuoka Prefecture and two chicken samples that exhibited resistance to ciprofloxacin had identical pulsed-field gel electrophoresis patterns, suggesting that ciprofloxacin-resistant C. jejuni could have been distributed in meat. S. aureus isolates showed the highest level of resistance to ampicillin and tetracycline. Resistance to tetracycline in S. aureus isolates from beef was lower than that seen in isolates from chicken and pork (P < 0.01). This study revealed that the prevalence of MRSA and VRE were low in food-producing animals and retail domestic meats in Japan, although Campylobacter isolates resistant to fluoroquinolone and erythromycin were detected. The occurrence of antimicrobial-resistant pathogens should be monitored continuously to improve the management of the risks associated with antimicrobial drug resistance transferred from food-producing animals to humans.