A survey of vector-borne bacteria in bat-associated mites (Mesostigmata: Macronyssidae and Spinturnicidae) from Brazil reveals the presence of Ehrlichia spp.

Macronyssid and spinturnicid mites are globally distributed ectoparasites of medical and veterinary relevance, with various species known to parasitize bats. Beyond their ecological importance, some macronyssid mites, such as Ornithonyssus bursa, are known to occasionally bite humans and cause dermatitis, highlighting the interface between wildlife, ectoparasites, and human habitats. Understanding the microorganisms harbored by bat-associated mites is therefore important from a One Health perspective, as these arthropods may act as bridge hosts for pathogens among bats, domestic animals, and humans. Although their role in pathogen transmission remains poorly understood, previous studies have reported bacterial agents in these mite groups. This study aimed to investigate the presence of several pathogens in macronyssid and spinturnicid mites collected from bats in Brazil. A total of 393 macronyssid and 210 spinturnicid mites parasitizing bats were analyzed through morphological and molecular approaches. Ehrlichia DNA was the only pathogen detected, found in 3.03% of macronyssid mites and 2.4% of spinturnicid mites from Rio de Janeiro State, previously described on bat-associated chigger mites. These findings underscore the need for further research into the ecological interactions between bats and their ectoparasites and the potential implications of these mites as vectors of zoonotic pathogens.