Isolation and molecular characterization of pathogenic Leptospira species from cattle in Zaria and its environs, Kaduna State, Nigeria.

Leptospirosis is a zoonotic disease caused by pathogenic serovars of Leptospira spp. The paucity of information on the status of leptospirosis in cattle in the study area led to this study. A cross-sectional study was carried out with a total of 130 kidney samples from cattle which were cultured using Ellinghausen Mc-Cullough Johnson Harris enrichment and examined on dark field microscope after 8 weeks of culture. DNA was extracted directly from 6 kidney tissues to confirm the presence of pathogenic Leptospira spp. and further sequenced to determine the species of Leptospira spp. Result of the culture indicated that the overall occurrence of Leptospira spp.was 32.30 %. Phylogenetic analysis of lipL32 sequences showed Leptospira interrogans isolates from cattle nucleotide homology ranging from 99.40 % to 99.73 % with a query cover of 100 % when compared with sequence from gene bank. In conclusion, this study established that cattle may act as a significant reservoir of leptospirosis in the study area and pose a potential risk to abattoir workers, veterinarians and local communities.

Prevalence of Leptospira interrogans in wild rats (Rattus norvegicus and Cricetomys gambianus) in Zaria, Nigeria.

Leptospirosis is a neglected disease of zoonotic importance and rodents have a known role in epidemiology of Leptospira globally. Paucity of information on the prevalence of leptospirosis in wild rats used as games in Zaria, Nigeria informed the study. The study aimed to detect Leptospira interrogans in wild rats in Zaria, Nigeria. A total of 71 wild rats comprising 57 Rattus norvegicus and 14 Cricetomys gambianus were sampled over a period of 3 months (April-June 2019). Fisher exact test was used with confidence interval set at 0.05 to ascertain associations between positive cases and species. Blood was collected from 56 rats and harvested sera screened for Leptospira interrogans antibody using rat IgG competitive enzyme linked immunosorbent assay (c-ELISA). Following humane euthanasia of rats, 71 samples (62 kidney tissues and 9 urine samples) were collected in sterile labeled tubes and cultured using Ellinghausen Mc-cullough Johnson Harris (EMJH) enrichment and basal medium. Results indicated over all Leptospira spp antibody detection of 73.2 % (41/56) in Rattus norvegicus (60.7 %) and Cricetomys gambianus (12.5 %). No significant difference (P > 0.05) existed for the prevalence of Leptospira interrogans antibody in the species of wild rats. Over all occurrence of Leptospira interrogans were 74.2 % (46/62) in kidneys and 55.6 % (5/9) in urine samples. Based on species of rats, Rattus norvegicus recorded prevalence of 76.9 % (40/52) and 40.0 % (2/5) in kidney and urine samples respectively. Prevalence of 60.0 % (6/10) and 75.0 % (3/4) in kidney and urine samples respectively were recorded for Cricetomys gambianus. There was significant difference (P < 0.05) in the prevalence of Leptospira interrogans in kidney samples of both wild rats. These species of rats could be reservoirs of Leptospira interrogans. The result showed high prevalence of Leptospira spp in the wild rats and the possibility of domestic animals and humans contracting the disease. This study is the first documentation of evidence of pathogenic Leptospira species in wildlife used as games in Zaria, Nigeria.