Molecular detection and epidemiological insights of Clostridioides difficile in Egyptian fruit bats

Abstract

Clostridioides difficile is a major global cause of antibiotic-associated diarrhea, increasingly recognized as a community- and zoonosis-linked pathogen with widespread environmental and animal reservoirs. Given the ecological overlap between bats, humans, and livestock and the limited data on bats, this study investigated the presence of C. difficile and its toxin genes in Egyptian bats to evaluate their potential role in the transmission cycle. Fifty fruit bats (Rousettus spp.) were captured and identified using standard morphological keys. Intestinal content samples were collected and cultured anaerobically in Cooked Meat Medium. DNA was extracted from isolates, and PCR was performed to detect C. difficile (tpi) and its toxin genes (tcdA, tcdB). C. difficile was detected in 64% of intestinal content samples (32/50), with 16 isolates (32%) identified as toxigenic. Among these, 21.8% were tcdA⁺/tcdB⁻, 15.6% tcdA⁻/tcdB⁺, and 12.5% carried both genes, while 32% of isolates were non-toxigenic. This study provides the first molecular evidence of toxigenic and non-toxigenic C. difficile in Egyptian fruit bats, prominence their potential role as environmental reservoirs. The findings highlight the need for bats investigation to clarify the possible transmission ways within human, animals and environment.