The usefulness of semi‐solid medium in the isolation of highly virulent Leptospira strains from wild rats in an urban area of Fukuoka,Japan |
| |
Authors: | Mitsumasa Saito Sharon Y A M Villanueva Toshiyuki Masuzawa Yusuke Haraguchi Shuhei Ita Satoshi Miyahara Ryo Ozuru Takayoshi Yamaguchi Michinobu Yoshimura Mami Ikejiri Natsumi Aramaki Muhammad Yunus Amran Lisa Tenriesa Muslich Ken‐ichiro Iida Yasutake Yanagihara Nina G Gloriani Shin‐ichi Yoshida |
| |
Institution: | 1. Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan;2. Laboratory of Microbiology and Immunology, Faculty of Pharmaceutical Sciences, Chiba Institute of Science, Choshi, Chiba, Japan;3. Department of Medical Microbiology, College of Public Health, University of the Philippines–Manila, Ermita, Manila, Philippines;4. University of Shizuoka, Shizuoka, Japan |
| |
Abstract: | Leptospirosis is a worldwide zoonosis. The importance of urban leptospirosis is recognized in Japan: urban rats carry pathogenic leptospires and people acquire these pathogens through contact with surface water or soil contaminated by the urine of the infected animals. To determine the current Leptospira carriage rate in urban rats, 29 wild rats were trapped in the central area of Fukuoka and strains isolated from their kidneys and urine analyzed. When semi‐solid Korthof's medium containing 0.1% agar was used for isolation, 72.2% and 30.8% of the kidney and urine cultures, respectively, were found to be Leptospira‐positive. The isolates belonged to Leptospira interrogans, and were classified into two groups (serogroups Pomona and Icterohaemorrhagiae) based on the results of gyrB sequence analysis and microscopic agglutination testing (MAT). Strains belonging to serogroup Icterohemorrhagiae grew well in liquid medium. On the other hand, serogroup Pomona isolates multiplied very little in liquid medium, but did grow in a semi‐solid medium. Although strains belonging to serogroup Pomona have not been recognized as native to Japan, this strain may be widely distributed in urban rats. Representative strains from each group were found to be highly pathogenic to hamsters. Our findings should serve as a warning that it is still possible to become infected with leptospires from wild rats living in inner cities of Japan. Furthermore, the use of semi‐solid medium for culture will improve the isolation rate of leptospires from the kidneys of wild rats. |
| |
Keywords: | Leptospira interrogans semi‐solid Korthof's mediom serogroup Pomona wild rat |
|
|