长角血蜱微生物群落及其共生菌的研究

lose relationships between ticks and microbial communities are important for tick fitness and pathogen colonization and transmission. Haemaphysalis longicornis, a three-host tick, distributed widely in China, can carry and transmit various pathogens and pose serious damages to public health and livestock. In the present study, we investigated the composition of bacterial communities associated with H. longicornis and evaluated the putative symbionts using molecular biology methods. The results showed that diverse microbial communities had been found from the field-collected H. longicornis. Three types of symbionts Coxiella-like（CLS-Hl和NCLS-Hl）, Arsenophonus-like（ALS-Hl）and Rickettsia-like symbionts（RLS-Hl）were identified in a single host simultaneously. In females, CLS-Hl colonized specifically in ovaries and malpighian tubes, while ALS-Hl and RLS-Hl infected all tissues tested (ovaries, salivary glands, malpighian tubes and midguts). In natural field population, CLS-Hl showed 100% infection rate; ALS-Hl occurred in 33.3% females and 83.3% males; the prevalence of RLS-Hl was 88.9% and 100% in females and males, respectively. However, only Coxiella-like bacteria were transmitted stably in the laboratory-reared ticks. We speculate that an obligate symbiotic association between Coxiella symbiont and its host. Our investigation of microbial communities in the ticks revealed the complexity of ecological interactions between host and microbe and provided insight for the biological control of ticks.