Prevalence and renal pathology of pathogenic Leptospira spp. in wildlife in Abeokuta, Ogun State, Nigeria

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.

Molecular epidemiology of Leptospira spp. among wild mammals and a dog in Amami Oshima Island, Japan

Leptospirosis is a worldwide zoonosis caused by the pathogenic Leptospira spp. Canine and human leptospirosis sometimes occur on Amami Oshima Island, located in the Nansei Archipelago, southwestern Japan; however, information on the causative Leptospira spp. on this island is quite limited. This study aimed to investigate the molecular and serological characteristics of Leptospira spp. isolated from wild animals and a dog in Amami Oshima Island. We obtained seven Leptospira strains by culturing kidney tissues of wild animals, such as black rats (2), wild boars (3), and rabbit (1) as well as blood from a symptomatic dog. Using flaB sequencing and microscopic agglutination test with antisera for 18 serovars, the isolates were identified as Leptospira borgpetersenii serogroups Javanica (black rat), L. interrogans serogroup Australis (black rat and dog), and L. interrogans serogroup Hebdomadis (wild boar and rabbit). The sequence type (ST) of L. borgpetersenii serogroup Javanica was determined to be ST143 via multilocus sequence typing (MLST) using seven housekeeping genes. For L. interrogans, MLST and multiple-locus variable-tandem repeat analysis (MLVA) revealed identical ST and MLVA types in rat and canine isolates, whereas two STs and MLVA types were identified in wild boar isolates. The STs and MLVA types of rabbit and one of the wild boars were identical. Bacterial culture and flaB-nested polymerase chain reaction demonstrated a high rate of Leptospira infection in wild boars (58.3%, 7/12), whereas Leptospira spp. were detected in 4.8% of black rats (2/42). This study revealed diverse Leptospira genotype and serotype maintenance in wild mammals on Amami Oshima Island. MLST and MLVA indicated that black rats were a source of canine infection. Wild boars carry L. interrogans and are considered an important maintenance host because antibodies against serogroup Hebdomadis were detected in human and canine leptospirosis patients on this island.

Detection of Pathogenic Leptospira Spp. in Goats from Slaughterhouses in Southwestern Nigeria Using Isolation, Histochemistry and Immunohistochemistry

Studies on caprine leptospirosis using isolation, histochemistry and immunohistochemistry are rare. The role of small ruminants in the epidemiology of leptospirosis is scarce. This study investigated the prevalence of Leptospira spp. serovars, and the renal pathology of caprine leptospirosis in slaughterhouses from two states in southwest Nigeria using isolation (IS), Warthin Starry silver (WSs) impregnation and immunohistochemistry (IH). One hundred and sixty-nine kidney samples were randomly obtained from goats between September 2015 and June 2017. Chi-square test was used with a confidence level set at 0.05 to ascertain associations between the positive cases, sex and animal species. Eighty-seven (51.5%) samples were positive on IS, out of which 26/40 and 25/30 were positive on WSs and IH, respectively. Ten (5.9%) kidneys showed macroscopic lesions while interstitial nephritis (48.6%) and tubular nephrosis (64.2%) were the most prominent histopathological changes. The most frequently observed positive reactions were against serovars Hardjo type Prajitno (12/25, 48%), and Gripptotyphosa (5/25, 20%). Other serovars such as Bratislava (2/25, 8%), Canicola (3/25, 12%), Icterohaemorrhagiae (2/25, 8%), and Pomona (1/25, 4.0%) were also detected using IH. The result showed high prevalence of Leptospira infection in goats and the possibility of humans contracting the disease. To date, the detection of leptospirosis from kidneys of goats using IS, WSs and IH has not been reported. This study is the first documentation of evidence of pathogenic Leptospira species in renal tissues of goats.

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.

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

The impact of leptospirosis on food animals and humans has not been fully elucidated. This study was designed to determine the prevalence of pathogenic Leptospira organism in renal tissues of slaughtered cattle from two major abattoirs in southwestern Nigeria. One hundred and seventy (170) kidney samples of different breeds, ages, and sexes were collected and examined using cultural isolation, microscopic agglutination test (MAT), Warthin silver (WSs) impregnation and immunohistochemistry (IH). Chi-square test was used with a confidence level set at 0.05 to ascertain associations between positive cases and sex, age, and breed. One hundred and thirty (76.5%) of the kidney samples were culturally positive while 83.3% (25/31), 41.6% (37/89), and 35% (7/20) were MAT, WSss, and immunohistochemically positive, respectively. Interstitial nephritis (87%, 94/108) and tubular nephrosis (77.8%, 84/108) were the most prominent and consistent microscopic lesions observed.Serovars Hardjoprajitno (29%) and Bratislava (22.6%) were the most prevalent serovars. To the best of our knowledge, studies on determination of pathogenic Leptospira serovars using cultural isolation, MAT, WSSs, and IH from kidneys of naturally infected cattle in Nigeria are rare. This study is the most comprehensive work in the detection of pathogenic Leptospira species from cattle in Nigeria.

Raccoons (Procyon lotor) and Striped Skunks (Mephitis mephitis) as Potential Reservoirs of Leptospira spp. in California

Leptospirosis is a globally important, fatal disease of humans, and over 160 species of animals are associated with more than 250 bacterial serovars in 64 species, but its ecology varies regionally and has changed over time with expansion of human development on previously agricultural and wild land. Sporadic human cases and clusters of canine leptospirosis, primarily attributable to Leptospira interrogans serogroup Pomona, have been detected in northern California. Small mesocarnivores such as raccoons and skunks frequent peridomestic space across much of the western United States and could serve as reservoirs for human and canine leptospirosis. We aimed to summarize the prevalence of infection with pathogenic leptospires in skunk and raccoon renal and urinary samples across broad geographic zones in California, and to determine whether prevalence changed during wet and dry seasons, and as functions of host species and demographic characters. Overall, 25.6% (22/86 tested) of raccoons and 28.5% (39/137 tested) of skunks were PCR-positive for Leptospira spp. in either renal tissue or urine, with leptospiral DNA in 22.0% of kidney samples and 18.8% of urine samples from raccoons and 27.8% and 14.5% of kidney and urine samples from skunks, respectively. Raccoons from the Central California and skunks from the San Francisco Bay Area had the highest overall PCR-prevalence (35.7% and 44.4%), respectively, and adults were more likely to be PCR-positive for Leptospira spp. than juveniles. There was moderate agreement between urine and renal tissue Leptospira spp. PCR with sensitivity for both host species in renal tissue of 0.86-0.97 and 0.42-0.64 in urine. Cases of human leptospirosis are thought to be underrecognized in the continental United States and possibly increasing in some states, including California. Our data document regionally high rates of infection in common mesocarnivores, which can pose a threat to humans and dogs, revealing an important periurban epidemiological cycle.

Blind Trading: A Literature Review of Research Addressing the Welfare of Ball Pythons in the Exotic Pet Trade

Simple Summary

The Ball python is a small species that is commonly kept as an exotic pet across the world. Despite huge numbers of these snakes being kept and traded in the pet industry, there is very little information available about how catching, breeding, transporting and housing them in captivity could impact their welfare. Our study reviewed the published literature for this species and found 88 relevant peer-reviewed scientific papers. Physical health was the predominant focus of research, with numerous studies reporting on disease, injury or clinical treatments. Far fewer papers focused on other aspects of Ball python wellbeing, including behaviour, nutrition, environment or mental condition. We also found that very few studies focused on wellbeing prior to pet ownership, i.e., during the early stages of the trade chain when they are caught from the wild, transported, or bred in captivity. We recommend that more research is needed to assess the impact of the exotic pet trade on this species’ welfare. In particular, research on welfare conditions during capture and transportation of wild Ball pythons, and the potential effects of captive breeding, could help reduce suffering throughout the trade.

Abstract

Extensive numbers of Ball pythons are caught, bred, traded and subsequently kept in captivity across the world as part of the exotic pet industry. Despite their widespread availability as pets, relatively little is known about the potential welfare challenges affecting them. We reviewed the literature for research focused on the health and welfare of Ball pythons in the international pet trade. From a total of 88 articles returned from the search criteria, our analysis showed that very few actually focused on trade (10%) or animal welfare (17%). Instead, the majority (64%) of articles focused on veterinary science. There was a considerable bias towards physical health, with most studies neglecting the four other domains of animal welfare (behaviour, nutrition, environment and mental health). Furthermore, very few studies considered Ball pythons prior to resulting pet ownership, during wild capture and transportation or captive breeding operations. Our review demonstrates that our current understanding of welfare for Ball pythons traded as exotic pets is limited. We recommend that future research should focus on aspects of the industry that are currently overlooked, including the potential consequences of genetic selection during captive-breeding and the conditions provided for snakes prior to and during international transportation.