Parasitic fauna of bats from Costa Rica

Molecular Survey of Protist Enteroparasites in Bats (Order Chiroptera) from Portugal

PURPOSE

Bats constitute 20% of all mammal species, playing a vital role in ecosystem health as pollinators, seed dispersers, and regulators of insect populations. However, these animals can also be reservoirs for infectious agents, including viruses, bacteria, and enteroparasites such as Cryptosporidium spp., Giardia duodenalis, and Balantioides coli, raising questions about their role in the epidemiology of these agents. Our study analyses bat faecal samples from Portugal with the aim of assessing the prevalence, distribution and diversity of enteroparasitic protozoa.

METHODS

We conducted a retrospective study that included 380 bat faecal samples collected between 2014 and 2018 in northern and central Portugal.

RESULTS

In our study, a Cryptosporidium spp. prevalence of 3.2% was identified, with genetic diversity observed and strains grouped with known bat genotypes. Giardia duodenalis was detected in 0.5% of the samples, exhibiting distinct genetic characteristics that may suggest a potential new assembly group encompassing bats and rodents. Finally, B. coli was detected in 0.26% of samples, representing the first observation of this ciliate in bats, with the identified genetic variant belonging to genotype B.

CONCLUSION

Our results provide valuable molecular epidemiological insights that underscore the importance of bats in the epidemiology of these enteroparasites. Furthermore, this is the first report of Cryptosporidium spp. and G. duodenalis in bat faeces samples from Portugal, and the first study worldwide to show that bats can shed B. coli in their faeces.

Trypanosoma cruzi in domestic and wild mammals in the northeast region of Colombia

Trypanosoma cruzi hosts can serve as a source of infection for animals, vectors, and humans, contributing to the establishment of Chagas disease (CD) in a given area. Traditionally, the Department of Córdoba has not been considered a transmission area for CD; however, the report of several acute cases of Chagas disease highlights the importance of studying the dynamics of disease transmission in this region. This study aimed to detect T. cruzi in domestic and wild mammals in the department of Córdoba. In 2017, a cross-sectional descriptive study was conducted in six villages in two municipalities in the department of Córdoba. Blood samples from dogs living in the zones were collected in EDTA vacutainer tubes for domestic mammals. Wild mammals were collected using Sherman and Tomahawk traps and mist nets in crops and peridomiciles. T. cruzi DNA was detected using the kinetoplast DNA (kDNA) variable region and the tandem repeat satellite region of T. cruzi as molecular targets. We sampled 168 dogs and 146 wild mammals. The detected prevalence of T. cruzi was 6.37%; the TcI lineage was found in D. marsupialis, H. anomalus, and one canine. A specimen of D. marsupialis with TcI and TcII lineages was also identified. T. cruzi DNA was detected in domestic and wild animals in the study area, indicating the circulation of the parasite in peridomestic environments. D. marsupialis may represent an important host in maintaining this region's wild and domestic cycle.

Molecular detection of Enterocytozoon bieneusi in bats from Portugal

Enterocytozoon bieneusi is a microsporidia commonly found in the gastrointestinal tract of humans and a wide range of other animals, constituting a major cause of microsporidiosis in humans. Although E. bieneusi has been detected in humans, domestic, and wild animals in Portugal, and its presence in bats has been linked to zoonotic characteristics, its occurrence in bats within the country has not been reported. In this study, we investigated the presence of E. bieneusi in 380 bat fecal samples collected in mainland Portugal through a nested PCR assay targeting the internal transcribed spacer region and the flanking small and large subunits of the ribosomal RNA. Enterocytozoon bieneusi was detected in one bat sample (i.e., 0.26%; Pipistrellus pipistrellus). Additionally, another sample tested positive for Enterocytozoon sp. Phylogenetic analysis of the obtained ITS sequence of E. bieneusi revealed clustering within the potentially zoonotic Group 1. This study represents the first report of E. bieneusi in a bat from Europe. Findings presented here contribute to an enhanced understanding of E. bieneusi epidemiology.

How significant are bats as potential carriers of zoonotic Cryptosporidium and Giardia?

Bats are known to harbour various pathogens and are increasingly recognised as potential reservoirs for zoonotic diseases. This paper reviews the genetic diversity and zoonotic potential of Cryptosporidium and Giardia in bats. The risk of zoonotic transmission of Cryptosporidium from bats to humans appears low, with bat-specific Cryptosporidium genotypes accounting for 91.5% of Cryptosporidium-positive samples genotyped from bats worldwide, and C. parvum and C. hominis accounting for 3.4% each of typed positives, respectively. To date, there have only been sporadic detections of Giardia in bats, with no genetic characterisation of the parasite to species or assemblage level. Therefore, the role bats play as reservoirs of zoonotic Giardia spp. is unknown. To mitigate potential risks of zoonotic transmission and their public health implications, comprehensive research on Cryptosporidium and Giardia in bats is imperative. Future studies should encompass additional locations across the globe and a broader spectrum of bat species, with a focus on those adapted to urban environments.