Effects of Diazinon Exposure on Urinary Shedding of Serogroup Hebdomadis in Mice.

Wild rodents are natural hosts of spp. and are exposed to various pesticides, some of which are immunotoxic. Rodent urine is an important source of infection for humans and other animals. We evaluated the effects of pesticide exposure on growth in mice. Diazinon, at doses of 0.2, 1, and 5 mg/kg/day, was orally administered continuously to mice infected with serogroup Hebdomadis for 32 days. The numbers of . in urine and kidney tissues were significantly lower in mice exposed to 5 mg/kg/day diazinon than in unexposed mice ( < 0.05). The urinary concentration of 2-isopropyl-6-methyl-4-pyrimidinol, the metabolite of diazinon, was comparable with the concentration at which viability of was decreased in in vitro assay, suggesting that it had toxic effects on . in the proximal renal tubules. Diazinon exposure reinforced -induced expression of inflammatory cytokine genes in kidney tissues, and an enhanced immune system might suppress growth. These results suggest that diazinon exposure may not increase the risk of transmission to humans through mice. This novel study evaluated the relationship between pesticide exposure and infection in mice, and the results could be useful for risk assessment of leptospirosis.