Pathogens in anurans from a seasonal tropical environment in Guanajuato, Mexico

Abstract

In the present study, we characterized species of bacteria and fungi across a frog community in a seasonal tropical environment in the Natural Protected Area (NPA) Las Musas, Guanajuato, Mexico, using morphological and biochemical protocols. Our three main objectives were to: i) identify the species of microorganisms present in the frog community, ii) determine microorganism prevalence and how it changes throughout the year, and iii) detect diseases and injuries caused by pathogens (bacteria and fungi). Across 150 anurans analyzed, seven species of anurans especies (Anaxyrus compactilis, Incilius occidentalis, Dryophytes arenicolor, D. eximius, Hypopachus variolosus, Lithobates neovolcanicus y Spea multiplicata) hosted at least four genera of pathogenic fungi (Penicillium, Rhizopus, Aspergillus y Batrachochytrium) and two genera of pathogenic bacteria (Aeromonas hydrophila and Pseudomonas sp.). We found the prevalence of positive cases was higher in autumn (0.51) than in summer (0.125). Lesions such as peeling of the skin on the belly and swelling of the extremities (red leg) were observed in four of the seven species. This study confirms the presence of bacterial and fungal pathogenic agents in this frog community, and serves as a precedent for future work on monitoring the state of amphibian population health in Guanajuato. It also provides support for the implementation of conservation strategies for this group of vertebrates.