Prevalence and diversity of leptospires in small mammals in Guinea

Background Leptospirosis is a zoonotic disease caused by Gram-negative bacteria of the genus Leptospira . Rodents and other small mammals are important natural reservoirs and play a key role in the maintenance and transmission of this zoonosis to humans and animals. The objective of this study was to determine the prevalence and characterize the diversity of Leptospira species circulating in native and invasive small mammals across three ecological zones in Guinea. Results A total of 334 small mammals were sampled, including 111 native and 223 invasive species. Molecular identification based on mitochondrial 16S rRNA and the universal cytochrome B gene revealed 20 species of small mammals. The most represented species were Mastomys natalensis (28.14%, 94/334), Praomys rostratus (26.94%, 90/334), and Rattus rattus (12.87%, 43/334). In addition, 10.17% (34/334) of the captured animals were shrews belonging to the genus Crocidura . Quantitative PCR targeting the 16S rRNA gene detected leptospiral DNA in 24.85% (83/334) of the small mammals. Genotyping of positive samples using the lipL41 gene identified two pathogenic species: Leptospira kirschneri in P. rostratus and Crocidura olivieri , and Leptospira interrogans in Uranomys ruddi and M. natalensis . Conclusions The results demonstrate that small mammals in Guinea harbor pathogenic Leptospira species with a relatively high prevalence. These findings highlight the importance of strengthening surveillance of leptospirosis in small mammals and other animal populations to better assess transmission risks and improve public health protection against this zoonosis in Guinea.