Molecular Detection and Genetic Identification of <i>Rickettsia</i> Infection in <i>Ixodes granulatus</i> Ticks, an Incriminated Vector for Geographical Transmission in Taiwan

• Main Authors: Chien-Ming Shih, Pei-Wen Yang, Li-Lian Chao
• Format: Article
• Language: English
• Published: MDPI AG 2021-06-01
• Series: Microorganisms
• Subjects: <i>Rickettsia</i>; <i>Ixodes granulatus</i>; tick; genetic identity; Taiwan
• Online Access: https://www.mdpi.com/2076-2607/9/6/1309

Tick-borne <i>Rickettsia</i> pathogens have become an emerging source of zoonotic infections and have a major impact on human health worldwide. In this study, the prevalence and genetic identity of <i>Rickettsia</i> infections in <i>Ixodes granulatus</i> ticks was firstly determined in Kinmen Island of Taiwan. A total of 247 <i>I. granulatus</i> ticks were examined for <i>Rickettsia</i> infection by nested-PCR assay targeting the citrate synthase (gltA) gene of <i>Rickettsia</i>. The <i>Rickettsia</i> infection was detected with a general infection rate of 4.86%, and was detected in nymph, male and female stages with an infection rate of 3.81%, 0% and 6.84%, respectively. Phylogenetic relationships were analyzed by comparing the gltA sequences obtained from four Taiwan strains and 19 other strains representing 13 genospecies of <i>Rickettsia</i>. Phylogenetic analyses reveal that all Taiwan strains were genetically affiliated to the genospecies of spotted fever (<i>R. parkeri</i>) and transitional (<i>R. felis</i>) groups of <i>Rickettsia</i>. Our findings reveal the first detection of <i>R. parkeri</i>-like and <i>R. felis</i> in <i>I. granulatus</i> ticks from Kinmen Island. As a tourist island between Taiwan and mainland China, these results demonstrate the epidemiological significance of diverse <i>Rickettsia</i> species existed in <i>I. granulatus</i> ticks and highlight the potential threat of geographical transmission among humans in the Taiwan area.