Leptospira in Bats from Hubei Province, China, 2018

Genetic diversity of P1/pathogenic Leptospira species hosted by bats worldwide

INTRODUCTION

Bats are a diverse group of mammals that have unique features allowing them to act as reservoir hosts for several zoonotic pathogens such as Leptospira. Leptospires have been classified into pathogenic, intermediate, and saprophytic groups and more recently into clades P1, P2, S1, and S2, being all the most important pathogenic species related to leptospirosis included within the P1/pathogenic clade. Leptospira has been detected from bats in several regions worldwide; however, the diversity of leptospires harboured by bats is still unknown.

AIM

The aim of the present study was to determine the genetic diversity of Leptospira spp. harboured by bats worldwide.

METHODS

A systematic review was conducted on four databases to retrieve studies in which Leptospira was detected from bats. All studies were screened to retrieve all available Leptospira spp. 16S rRNA sequences from the GenBank database and data regarding their origin. Sequences obtained were compared with each other and reference sequences of Leptospira species and analysed through phylogenetic analysis.

RESULTS

A total of 418 Leptospira spp. 16S rRNA sequences isolated from 55 bat species from 14 countries were retrieved from 15 selected manuscripts. From these, 417 sequences clustered within the P1/pathogenic group, and only one sequence clustered within the P2/intermediate group. Six major clades of P1/pathogenic Leptospira spp. were identified, three of them composed exclusively of sequences obtained from bats.

CONCLUSION

We identified that bats harbour a great genetic diversity of Leptospira spp. that form part of the P1/pathogenic clade, some of which are closely related to leptospirosis-associated species. This finding contributes to the knowledge of the diversity of leptospires hosted by bats worldwide and reinforces the role of bats as reservoirs of P1/pathogenic Leptospira spp.

Spatiotemporal assessment of pathogenic Leptospira in subtropical coastal watersheds

The World Health Organization classifies leptospirosis as a significant public health concern, predominantly affecting impoverished and unsanitary regions. By using the Pensacola Bay System as a case study, this study examines the underappreciated susceptibility of developed subtropical coastal ecosystems such as the Pensacola Bay System to neglected zoonotic pathogens such as Leptospira. We analyzed 132 water samples collected over 12 months from 44 distinct locations with high levels of Escherichia coli (>410 most probable number/100 mL). Fecal indicator bacteria (FIB) concentrations were assessed using IDEXX Colilert-18 and Enterolert-18, and an analysis of water physiochemical characteristics and rainfall intensity was conducted. The LipL32 gene was used as a quantitative polymerase chain reaction (qPCR) indicator to identify the distribution of Leptospira interrogans. The results revealed 12 instances of the presence of L. interrogans at sites with high FIB over various land cover and aquatic ecosystem types. Independent of specific rainfall events, a seasonal relationship between precipitation and elevated rates of fecal bacteria and leptospirosis was found. These findings highlight qPCR's utility in identifying pathogens in aquatic environments and the widespread conditions where it can be found in natural and developed areas.

Study on the relation of the characteristics of the capture sites with the Leptospira spp. occurrence in bats and rodents from Yucatan, Mexico

This study aims to describe the natural Leptospira occurrence in small mammals from Yucatan, Mexico, and to explore the relation between the characteristics of the capture sites and the Leptospira occurrence. Bats and rodents were captured in five sites of Yucatan state, and from them, a kidney fragment was collected that was used in the genomic DNA extraction. Leptospira DNA was identified by PCR targeting the 16S-rRNA and LipL32 genes. Additionally, a bioinformatic analysis was carried out to know the Leptospira species and was corroborated with a phylogenetic tree. The assemblage of small mammals was compound of 82 (51.2 %) bats and 78 (48.8 %) rodents. A global frequency (bats plus rodents) of Leptospira occurrence of 21.2 % (34/160) was observed; in bats, it was 21.9 % (18/82), and in rodents, 20.5 % (16/78). The phylogenetic trees based on LipL32 gene showed that the recovered sequences most closely resemble the species L. borgpetersenii and L. noguchii. The ordination of the capture sites with tropical deciduous forests as original vegetation is more related to the abundance of Leptospira-infected rodents. The ordination of the capture sites with tropical sub-deciduous forests as original vegetation is more related to the diversity of Leptospira-infected bat species. The canonical ordering of the capture sites is by the original vegetation type and the diversity and abundance of Leptospira-infected bat and rodent species.

Prevalence and Characteristics of Novel Pathogenic Leptospira Species in Bats in Yunnan Province, China

Leptospirosis has been identified as a zoonotic disease caused by pathogenic spirochetes of the bacterial genus Leptospira. Rodents are considered the primary hosts of these bacteria, whereas many recent studies suggest that bats may serve as potential natural reservoirs. However, studies on pathogenic spirochetes hosted by bat populations still need to be completed in China. In this study, a total of 276 bats belonging to five genera collected in Yunnan Province (Southwest China) from 2017 to 2021 were included in the screening. Pathogenic spirochetes were detected by PCR amplification and sequencing targeting four genes (rrs, secY, flaB, and LipL32), resulting in 17 positive samples. Phylogenetic analysis based on multi-loci concatenated sequences, inferred by MLST approach, identified the strains as two novel Leptospira species within the pathogenic group. Of note, only Rousettus leschenaultii was found to harbor these spirochetes, suggesting it may be one of the potential natural reservoirs in circulating leptospires in this region. Nevertheless, the pathogenesis and transmission dynamics still need to be fully understood, requiring in-depth studies on other animals and the surrounding population.

Neuro-leptospirosis - A batty diagnostic enigma

Leptospirosis is an important, worldwide zoonotic, with a high incidence in warm-climate and tropical countries. Leptospirosis has a broad spectrum of manifestations, from a non-specific febrile illness to severe disease with multi-organ involvement. Transmission typically occurs following exposure to urine from infected animals, in particular domesticated animals such as rodents and cattle. Leptospira species have been identified in bats, however bat-human transmission is uncertain, and bat-associated leptospirosis in humans is seldom reported. We report a unique case of severe neuro-leptospirosis resulting from bat exposure with an unusual manifestation of a non-traumatic subarachnoid haemorrhage, and the diagnostic challenges it presented.

Detection of Leptospira interrogans in Hedgehogs from Central China

Background: Leptospira is the causative agent of leptospirosis, a zoonotic disease of global importance. To have a better understanding on the host species of Leptospira, we investigated the prevalence of Leptospira species in hedgehogs in Central China. Materials and Methods: Hedgehogs were captured in Hubei Province, China in May and October, 2018. Total DNA was extracted from the kidney tissues of hedgehogs for determining the Leptospira species by PCR amplification of the rrs2, secY, and flaB genes with genus-specific primers. Results: PCR amplification indicated that the positive rate of hedgehogs to the rrs2, secY, and flaB genes were 19.5% (8/41), 12.2% (5/41), and 9.8% (4/41), respectively. The homology of the partial sequence of rrs2, secY, and flaB genes were 99.0-100% among the Leptospira strains from hedgehogs. Phylogenetic analysis revealed that Leptospira species detected in this study clustered together with Leptospira interrogans. Conclusions: We detected L. interrogans from hedgehogs in Central China, suggesting hedgehogs are the hosts of L. interrogans.

First record of Leptospira and Blastocystis infections in captive flying squirrels (Trogopterus xanthipes) from Enshi County, China

In traditional Chinese medicine, the feces of flying squirrels have long been used to promote blood circulation and relieve bodily stasis. However, the excrement of flying squirrels may harbor zoonotic agents that could be hazardous to public health. To understand the occurrence of bacterial and parasitic infections in this species, we investigated selected zoonotic pathogens including Leptospira and Blastocystis in the urine and feces of flying squirrels in China. Urine and fecal samples from flying squirrels were collected from a family-owned flying squirrel farm located in Enshi County, Hubei Province in China. Leptospira and Blastocystis DNA was extracted from the urine and feces of flying squirrels, and used as targets for PCR amplification, using different specific primers. PCR amplification and DNA sequencing showed that 4.4% (3/69) of flying squirrels were positive for Leptospira, while 30.4% (21/69) of the animals were positive for Blastocystis. Notably, 1.4% (1/69) of flying squirrels were found to be co-infected with Leptospira and Blastocystis. Sequence analyses allowed for the detection of 3 Blastocystis subtypes (ST1, ST3 and ST13), and mixed infections of Blastocystis subtype 1 and subtype 3 were found in 4.4% (3/69) of flying squirrels. Phylogenetic analysis of the 16S ribosomal RNA gene (rrs2), the flagellin B gene (flaB), and outer membrane lipoprotein lipL32 gene (LipL32) sequences indicated that the Leptospira species detected in the study was L. interrogans. We concluded that flying squirrels from central China were infected with Leptospira and Blastocystis, suggesting that these animals can be a source of infection for their owners, and using fresh excrement from this animal as traditional medicine could be risky to human health. To the best of our knowledge, this is the first report of Leptospira and Blastocystis infection in flying squirrels from Enshi County, China. Our findings provide new data on the epidemiology of these pathogens in this region.