Cats as potential mammalian reservoirs for Rickettsia sp. genotype RF2125 in Bangkok, Thailand

Pornkamol Phoosangwalthong; Sze Fui Hii; Ketsarin Kamyingkird; Chanya Kengradomkij; Nongnuch Pinyopanuwat; Wissanuwat Chimnoi; Rebecca J Traub; Tawin Inpankaew

doi:10.1016/j.vprsr.2018.07.001

Cats as potential mammalian reservoirs for Rickettsia sp. genotype RF2125 in Bangkok, Thailand

Vet Parasitol Reg Stud Reports. 2018 Aug:13:188-192. doi: 10.1016/j.vprsr.2018.07.001. Epub 2018 Jul 3.

Authors

Pornkamol Phoosangwalthong¹, Sze Fui Hii², Ketsarin Kamyingkird¹, Chanya Kengradomkij¹, Nongnuch Pinyopanuwat¹, Wissanuwat Chimnoi¹, Rebecca J Traub³, Tawin Inpankaew⁴

Affiliations

¹ Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand.
² Australian Rickettsial Reference Laboratory, Geelong, Victoria 3220, Australia.
³ Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria 3010, Australia.
⁴ Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand. Electronic address: tawin.i@ku.th.

PMID: 31014872
DOI: 10.1016/j.vprsr.2018.07.001

Abstract

Rickettsia felis is an obligate intracellular alpha-proteobacteria and the cause of flea-borne spotted fever (FBSF), an emerging zoonosis of global public health importance, for which dogs and cats have been implicated as potential mammalian reservoirs hosts. The purpose of this study was to determine the prevalence and associated risk factors for R. felis-like species in semi-domesticated cats and their fleas in aim of understanding public health risks posed by cats and their fleas in Bangkok, Thailand. Single whole blood samples (n = 432) and where observed, fleas (n = 234), were collected from cats from 53 temple communities in Bangkok. Fleas were morphologically and genetically identified to a species level. Cat blood and fleas were subjected to a spotted fever group (SFG)-specific PCR targeting the partial outer membrane protein B (ompB). Those that were positive, were further characterised using an R. felis-specific nested PCR targeting the partial citrate synthase A (gltA) gene. All fleas were identified as Ctenocephalides felis felis. In total SFG Rickettsiae were detected in the blood of 82/482 (17.01%) cats and 3/234 fleas (1.28%). DNA sequencing of the partial ompB characterised all positive amplicons from cat blood and their fleas as 100% identical to Rickettsia endosymbiont of Ctenocephalides felis orientis isolate (Rickettsia sp. genotype RF2125) and Rickettsia asemboensis (GenBank accession no. KP256362 and KY650699, respectively). The gltA gene targeting R. felis was successfully amplified from 12/82 PCR-positive cat blood samples and these clustered with 99% bootstrap support with isolates within the Rickettsia sp. genotype RF2125 clade. Cats that were permitted to roam freely inside monasteries were more likely to be infected with R. felis compared with cats confined indoors. The results suggest that cats in Thailand are potential mammalian reservoir hosts for Rickettsia sp. genotype RF2125.

Keywords: Bangkok; Fleas; PCR; Rickettsia felis; Rickettsia sp. genotype RF2125; Stray cats.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Animals, Wild / microbiology
Cat Diseases / epidemiology
Cat Diseases / microbiology
Cats / microbiology*
Ctenocephalides / microbiology
Disease Reservoirs / microbiology
Disease Reservoirs / veterinary*
Female
Genotype
Male
Prevalence
Public Health
Rickettsia / classification*
Rickettsia / isolation & purification
Rickettsia Infections / epidemiology
Rickettsia Infections / veterinary*
Rickettsia felis / genetics
Risk Factors
Sequence Analysis, DNA
Thailand / epidemiology