Cultural, histochemical, and immunohistochemical detection of pathogenic Leptospira species in the kidneys of cattle slaughtered in two abattoirs in Southwest Nigeria

Pathological and molecular study of kidneys in apparently healthy cattle and sheep with special reference to Leptospira species in central and northern Jordan

Background and Aim

Renal pathological conditions can cause significant economic losses for livestock owners. This study investigated and described the gross pathology and histopathology of lesions found in the kidneys of sheep and cattle, with particular attention to the presence of Leptospira spp.

Materials and Methods

Three hundred and sixty kidneys from apparently healthy sheep and cattle (208 and 152, respectively) were collected from slaughterhouses in Jordan for gross and histopathological examinations, multiplex polymerase chain reaction (PCR) analysis, and gene sequencing of Leptospira spp.

Results

Histopathological analysis of the samples revealed the following conditions: interstitial nephritis (4.44%), glomerulonephritis (4.16%), acute tubular necrosis (17.22%), and renal congestion (4.72%). In addition, in 26.9% of the samples, hyaline material was observed in the interstitium of the cortex and medulla. The PCR results revealed that 83 (23.1%) of the 360 samples were positive for Leptospira spp. 16S rRNA, 42/152 (28%) of cattle, and 41/208 (20%) of sheep. Four samples (two sheep and two cattle) were sequenced and deposited in GenBank with accession numbers from OL701310 to OL701313. Basic Local Alignment Search Tool search and nucleotide similarities between OL701311 and OL701313 resulted in the highest similarities with different Leptospira borgpetersenii strains, whereas OL701310 showed the highest nucleotide similarity (99.2%) with the Leptospira interrogans strain. Similarly, phylogenetic analysis revealed that OL701311 to OL701313 clustered together with different serovars of L. borgpetersenii, whereas OL701310 clustered with the L. interrogans clade.

Conclusion

This is the first study to reveal a close association between pathogenic Leptospira spp. and kidney disorders in Jordanian cattle and sheep. These findings may help expand the current understanding of the causes and mechanisms of renal disease in cattle and sheep and contribute to developing more effective prevention and treatment programs.

Leptospirosis in humans and selected animals in Sub-Saharan Africa, 2014-2022: a systematic review and meta-analysis

BACKGROUND

Leptospirosis is an emerging neglected tropical zoonotic disease of public health importance causing substantial morbidities and mortalities among humans. The infection is maintained within the population through interactions between humans, animals, and the environment. Understanding the burden of disease in both humans and animals is necessary for effective prevention and control in Sub-Saharan Africa (SSA). Therefore, we aimed to determine the seroprevalence of leptospirosis in humans, selected domestic animals, and rodents in SSA.

METHODS

A comprehensive search was done in six databases: Scopus, PubMed, Google Scholar, CINAHL, Web of Science, and African Journals Online databases for articles published between 01 January 2014 and 30 August 2022. Thirty-seven articles distributed across 14 out of 46 countries in SSA were included. The random effects meta-analysis model was used to pool the extracted seroprevalence data.

RESULTS

The overall pooled seroprevalence of leptospirosis among humans was 12.7% (95% CI: 7.5,20.8), 15.1% (95% CI: 9.4,23.5), and 4.5% (95% CI: 0.4, 35.6) based on results obtained using ELISA, MAT, and PCR diagnostic methods respectively. The pooled seroprevalence estimates among cattle were 29.2%, 30.1%, and 9.7% based on ELISA, MAT, and PCR respectively. Further, the pooled seroprevalence in goats was 30.0% for studies that used MAT, and among rodents, the pooled seroprevalence estimates were 21.0% for MAT and 9.6% for PCR diagnostic criteria. The seroprevalence of leptospirosis varied extensively between studies, across SSA regions and study setting (rural or urban).

CONCLUSION

Leptospirosis is widespread in SSA in both humans and animals based on the current results of the pooled seroprevalence in the limited studies available. The burden is high in animals and humans and underestimated due to limited studies and challenges with limited diagnostic capacity in most healthcare settings in SSA. Hence, we recommend that leptospirosis should be listed as a disease of concern and be included on the list of routine diagnostics among patients presenting with febrile illness in healthcare settings. Further, we recommend the enhancement of surveillance of leptospirosis in all countries in SSA and the development of strategies with a One Health perspective to effectively prevent and control leptospirosis.

Serological and Molecular evidence of pathogenic Leptospira species in cattle from slaughterhouses in Veracruz State, Mexico

Cattle raising is the most important livestock activity in Mexico, highlighting the fact that the Country is eight place worldwide in the production of bovine meat. However, cattle can be affected by leptospirosis (a bacterial disease caused by 17 species of spirochetes of the genus Leptospira), which cause reproductive problems that translate into great economic losses. Additionally, these zoonotic agents can cause a rapidly evolving febrile condition in humans, which can be solved after the first week of symptoms or could progress to develop a severe late-phase manifestations. Despite the great impact of these agents on the economy and Public Health, epidemiological surveillance against the infectious disease that cause is not present in municipal slaughterhouses (MS). Therefore, the aim of this study was to identify, using serological and molecular methods, the circulating Leptospira species in three MS in Veracruz State. The frequency of anti-Leptospira antibodies was 67.5%. Additionally, five sequences were recovered that were 99% similar to L. interrogans. This work represents the first national effort for the evaluation of MS as sentinel units, that allow establishing the diversity of species of the genus Leptospira that circulate in cattle and establishing intervention measures for workers risk mitigation, who come into contact with the fluids and organs of infected animals.

Molecular detection and characterization of pathogenic Leptospira species in bats (Chiroptera) roosting in human habitats in Nigeria, West Africa

Leptospirosis is a neglected zoonosis with a nearly global distribution. In order to determine the role of bats in the epidemiology of leptospirosis in Nigeria, a total of 231 bats belonging to three families, Pteropodidae (n = 117), Molossidae (n = 107) and Nycteridae (n = 17), roosting in human habitats were screened by PCR and sequencing for the detection of pathogenic Leptospira species. DNA extracted from the kidneys of bats were subjected to conventional PCR targeting the rrs1, rrs2, flaB and secY genes for the detection of pathogenic Leptospira spp. Overall, 27 out of the 231 (11.7%) of the samples screened were positive for Leptospira spp. High prevalence (>80%) of Leptospira spp. DNA was detected in Chaerophon and Nycteris bat species captures in an abandoned well located within a human habitation. Sequences generated in this study were highly identical to Leptospira borgpetersenii and Leptospira interrogans and clustered with sequences of pathogenic species in GenBank. The detection of pathogenic Leptospira spp. was significantly associated (p < .001) with the bat species, feeding habit, roosting site and study location. To the best of our knowledge, this is the first molecular detection and characterization of pathogenic Leptospira spp. in bats from Nigeria. Results show that bats in Nigeria are infected with diverse Leptospira genotypes phylogenetically related to known pathogenic, including zoonotic taxa. Together, these findings reinforce bats' roles as potential reservoirs of Leptospira spp. and should be considered as a starting point for future comparative studies to improve our understanding of the epidemiology of this bacterial pathogen in Nigeria.