Trends in Bacterial Pathogens of Bats: Global Distribution and Knowledge Gaps

Abstract

Bats have received considerable recent attention for infectious disease research because of their potential to host and transmit viruses, including Ebola, Hendra, Nipah, and multiple coronaviruses. These pathogens are occasionally transmitted from bats to wildlife, livestock, and to humans, directly or through other bridging (intermediate) hosts. Due to their public health relevance, zoonotic viruses are a primary focus of research attention. In contrast, other emerging pathogens of bats, such as bacteria, are vastly understudied despite their ubiquity and diversity. Here, we describe the currently known host ranges and geographic distributional patterns of potentially zoonotic bacterial genera in bats, using published presence-absence data of pathogen occurrence. We identify apparent gaps in our understanding of the distribution of these pathogens on a global scale. The most frequently detected bacterial genera in bats are Bartonella, Leptospira, and Mycoplasma. However, a wide variety of other potentially zoonotic bacterial genera are also occasionally found in bats, such as Anaplasma, Brucella, Borrelia, Coxiella, Ehrlichia, Francisella, Neorickettsia, and Rickettsia. The bat families Phyllostomidae, Vespertilionidae, and Pteropodidae are most frequently reported as hosts of bacterial pathogens; however, the presence of at least one bacterial genus was confirmed in all 15 bat families tested. On a spatial scale, molecular diagnostics of samples from 58 countries and four overseas departments and island states (French Guiana, Mayotte, New Caledonia, and Réunion Island) reported testing for at least one bacterial pathogen in bats. We also identified geographical areas that have been mostly neglected during bacterial pathogen research in bats, such as the Afrotropical region and Southern Asia. Current knowledge on the distribution of potentially zoonotic bacterial genera in bats is strongly biased by research effort towards certain taxonomic groups and geographic regions. Identifying these biases can guide future surveillance efforts, contributing to a better understanding of the ecoepidemiology of zoonotic pathogens in bats.

Serum proteomics reveals a tolerant immune phenotype across multiple pathogen taxa in wild vampire bats

“…In recent decades, there has been an increasing interest in understanding bat immune responses to infections, particularly those involving viruses ( 17 , 62 , 63 ). However, insights into how bat immune systems respond to other pathogen taxa (e.g., bacteria and protozoa) are also relevant given their high infection prevalence and zoonotic potential ( 25 , 28 ). Proteomic tools have provided valuable insights into how bats cope with infections, especially in wild populations ( 33 , 36 – 38 ).…”

“…Additionally, bat immune responses against other intracellular pathogens (e.g., many bacteria) and extracellular pathogens (e.g., many protozoa) are even less studied. Because these non-viral infections are common and highly prevalent in wild bats ( 28 , 29 ), distinct mechanisms may potentially exist to cope with these infections.…”

The Role of Anthropogenic Roosting Ecology in Shaping Viral Outcomes in Bats

“…Additionally, our modeling approach with roosting ecology and link prediction suggested here could be readily adapted to trait-based analyses of other pathogens. Bat–bacterial associations are especially understudied, as research effort is increasingly focused on determinants of viral outcomes (Shaw et al 2020, Szentivanyi et al 2023).…”

Advances in understanding bat infection dynamics across biological scales

“…microorganisms detected in or isolated from bats) date back to rabies virus investigations in the early 1900s [1]. In the past two decades, following the emergence of Severe Acute Respiratory Syndrome (SARS) coronavirus (CoV) in 2003 and SARS-CoV-2 in 2019, there has been a dramatic increase in research on bat-associated microbes, including viruses, bacteria, haemosporidians and fungi [2][3][4][5]. These microbes may or may not cause disease in bats, and thus we broadly use the term 'microbes' rather than 'pathogens' throughout this paper to acknowledge that detecting microorganisms in bats is distinct from the process of determining pathogenicity [6].…”