Identification of Leptospira interrogans in Ototylomys phyllotis (Rodentia: Cricetidae) from Yucatan, Mexico

Abstract

Small rodents are the most relevant natural reservoirs of pathogenic Leptospira species. Several species of these small rodents have been described as carriers in Yucatan, Mexico. It is recognized that identifying the carriers and knowing their distribution is relevant to reducing the transmission risk of Leptospira spp. to susceptible hosts, including humans. The aim is to evidence the presence of pathogenic Leptospira spp. in small rodents captured in Tinum, Yucatan, Mexico. Forty–seven rodents of the species Heteromys gaumeri, Ototylomys phyllotis, Peromyscus yucatanicus, Sigmodon hispidus and Mus musculus were captured in four sites from the study municipality. A kidney fragment was collected and used in the extraction of total DNA. Two endpoint polymerase chain reactions (PCR) were used to detect Leptospira spp. DNA. The bioinformatic analysis and the construction of a phylogenetic tree determined the bacteria species. The reactions showed a total infection frequency of 8.5 % (95 % CI 3.3 – 19.9 %). All positive specimens were O. phyllotis. The species identified in the bioinformatic analysis and the phylogenetic tree was L. interrogans. This Leptospira species is relevant for public health because it is responsible for most severe cases of leptospirosis in humans. Likewise, it has been previously identified in small rodents from Mexico and Yucatan. The study shows that O. phyllotis carries L. interrogans. More research is needed to determine the risk of transmission to other hosts, including humans.