Rickettsia asembonensis in fleas from wild and domestic hosts in Italy

This study provides the first molecular evidence and surveillance data of Rickettsia asembonensis in Sardinia, Italy, detected in fleas ( Pulex irritans, Xenopsylla cheopis , and Archaeopsylla erinacei ) collected from domestic (goat, dog, cat, and pig) and wild (wild boar, fox, kestrel, crow, pigeon, peacock, buzzard, hen, barn owl, martin, hedgehog, owl, and flamingo) hosts in Sardinia between 2021 and 2024. Multilocus molecular analyses of gltA, ompA, ompB, Sca4 , and htrA genes revealed sequences with 100% identity to R. asembonensis strains previously reported from Brazil, Peru, Argentina, Thailand, and Malaysia, while all lice examined tested negative. These findings broaden current understanding of Rickettsia diversity in the Mediterranean region and highlight the importance of integrated surveillance involving diverse ectoparasite species. Sustained molecular monitoring of fleas and their hosts will be vital to clarify the ecology, distribution, and potential zoonotic relevance of R. asembonensis and other emerging Rickettsia species in southern Europe.