Abstract
Background: A wide range of vector-borne disease pathogens is known to be transmitted by fleas worldwide. Rickettsia typhi and Rickettsia felis are flea-borne pathogens causing murine typhus and flea-borne spotted fever respectively. Cases of rickettsial diseases viz., Spotted fever group rickettsiae and Typhus group rickettsiae have been frequently reported from Northeast (NE) India (at the confluence of Indo-Malayan, Indo–Chinese and Indian bio-geographical realms). This region has a predominantly humid subtropical climate that is favorable for the proliferation of rickettsial vectors. To understand the related risk factors of rickettsial infections, entomological studies were carried out concurrently with studies on rickettsial infections in Nagaland, a hilly state in NE India. The present study was performed to investigate the presence of rickettsiae causing vectors and their likely pathogens in the Mon district of Nagaland, India. Methods and materials: Fleas and ticks infesting domestic animals (dogs and cats) were collected from 3 localities of Mon. All specimens were identified to species level using standard taxonomic keys. Genomic DNA was extracted followed by molecular characterization. ITS1, ITS2 and COI regions along-with Rickettsia specific 17 kDa gene and gltA gene were targeted for amplification. Phylogenetic and molecular evolutionary analyses were done by using MEGA6. Results: Out of 20 pools of fleas and ticks, one flea specimen–Ctenocephalide spp was identified by DNA barcoding and was found PCR positive for Rickettsia specific 17 kDa and gltA genes. MLST targeting the 17-kDa and gltA genes shows that it is closely related to R. asembonensis. This is the first report of R. asembonensis infecting cat fleas from a remote village in NE, India. Conclusion: Rickettsia asembonensis belongs to a group of R. felis–like organisms that are similar, yet distinct from their closest known relative R. felis. Initially identified in domestic fleas from Kenya, there are recent reports of this pathogen from America, Asia, Europe, and Africa as well. Moreover, research concerning the hosts of R. asembonensis, its arthropod vectors, and its potential for interference with other rickettsial flea-borne pathogens (R. felis and R. typhi), will be crucial to define human infection risks in the region.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
