Abstract
BACKGROUND: Increasing molecular evidence supports that bats and/or their ectoparasites may harbor vector-borne bacteria, such as bartonellae and borreliae. However, the simultaneous occurrence of rickettsiae in bats and bat ticks has been poorly studied. METHODS: In this study, 54 bat carcasses and their infesting soft ticks (n = 67) were collected in Shihezi City, northwestern China. The heart, liver, spleen, lung, kidney, small intestine and large intestine of bats were dissected, followed by DNA extraction. Soft ticks were identified both morphologically and molecularly. All samples were examined for the presence of rickettsiae by amplifying four genetic markers (17-kDa, gltA, ompA and ompB). RESULTS: All bats were identified as Pipistrellus pipistrellus, and their ticks as Argas vespertilionis. Molecular analyses showed that DNA of Rickettsia parkeri, R. lusitaniae, R. slovaca and R. raoultii was present in bat organs/tissues. In addition, nine of the 67 bat soft ticks (13.43%) were positive for R. raoultii (n = 5) and R. rickettsii (n = 4). In the phylogenetic analysis, these bat-associated rickettsiae clustered together with conspecific sequences reported from other host and tick species, confirming the above results. CONCLUSIONS: To the best of our knowledge, DNA of R. parkeri, R. slovaca and R. raoultii was detected for the first time in bat organs/tissues. This is also the first molecular evidence for the presence of R. raoultii and R. rickettsii in bat ticks. To our knowledge, R. parkeri was not known to occur in Asia. Our results highlight the need to assess rickettsial agents in a broader range of bat species and associated tick species.