背景:Vector/tick传播的病原体(V/TBP)对全球人类和动物健康构成潜在威胁。关于犬V/TBP的信息很少,到目前为止,还没有进行具体的研究来探索来自巴基斯坦的狗的蜱虫中的微生物多样性。在这里,通过评估对公众和犬科动物健康具有特殊意义的ixodid蜱中V/TBP的遗传多样性和流行模式来解决这一知识差距.
方法:从开伯尔-普赫图赫瓦省中部(KP)的300只狗中收集了1150只硬蜱,巴基斯坦。经过形态分子鉴定,通过扩增16SrRNA/gltA(Rickettsia/Ehrlichia和Wolbachiasp。),18SrRNA(Theileriasp。)和cox1(Dirofilariasp.)基因通过PCR进行测序和系统发育研究。
结果:在toto中,发现50个丙氧代蜱(50/120,41.7%)对V/TBPDNA呈阳性。检测到的V/TBP分为五属八种,viz.埃里希亚(E.犬和埃里希氏菌。),立克次体(R.Massiliae,R.raoultii和立克次体sp.),Theileria(T.环形),Dirofilaria(D.immitis)和Wolbachia(Wolbachiasp.).病原体流行模式表明,广生R.massiliae是最普遍的人畜共患V/TBP(19.5%),其次是E.canis(10.8%),立克次体sp.(7.5%),R.raoultii(6.7%),T、环形(5.8%),D.immitis(5.8%),Wolbachiasp.(4.2%)和埃里希菌。(3.3%),分别。在筛选的蜱物种中,发现大多数血脂素样品的V/TBPDNA呈阳性(20/20,100%),其次是Rh。严格的turanicussericu(13/20,65%),口蹄疫(8/20,40%),Rh.嗜血杆菌(6/20,30%),Hy.漏斗(2/20,10%)和Rh。微加(1/20,5%)。在蜱标本中也检测到V/TBP的同时发生(单个V/TBP感染:32只蜱;两个和三个:13和5只蜱样本)。检测到的病原体与来自旧世界和新世界国家的NCBIGenBank上发表的类似分离株具有系统发育关系。
结论:感染狗的Ixodid蜱具有多种V/TBP,包括来自巴基斯坦的人畜共患病原体。此外,感染狗的蜱虫中D.immitis的存在增加了这种寄生虫在以狗为食时已经达到其死胡同宿主(即蜱)的可能性,或者已经扩大了其中间/paratenic宿主的范围。需要进一步的研究工作来调查流行病学,并确认从巴基斯坦筛选的蜱菌种对这些病原体的媒介能力。
BACKGROUND: Vector-/tick-borne pathogens (V/TBPs) pose a potential threat to human and animal health globally. Information regarding canine V/TBPs is scarce and no specific study has been conducted so far to explore the microbial diversity within ticks infesting dogs from Pakistan. Herein, this knowledge gap is addressed by assessing the genetic diversity and prevalence pattern of V/TBPs in ixodid ticks with special implications for public and canine health.
METHODS: A total of 1150 hard ticks were collected from 300 dogs across central Khyber Pakhtunkhwa (KP), Pakistan. After morpho-molecular identification, 120 tick samples were screened for the presence of V/TBPs by amplifying 16S rRNA/gltA (Rickettsia/Ehrlichia and Wolbachia sp.), 18S rRNA (Theileria sp.) and cox1 (Dirofilaria sp.) genes through PCR followed by sequencing and phylogenetic study.
RESULTS: In toto, 50 ixodid ticks (50/120, 41.7%) were found positive for V/TBPs DNA. The detected V/TBPs were categorized into five genera and eight species, viz. Ehrlichia (E. canis and Ehrlichia sp.), Rickettsia (R. massiliae, R. raoultii and Rickettsia sp.), Theileria (T. annulata), Dirofilaria (D. immitis) and Wolbachia (Wolbachia sp.). The pathogen prevalence patterns showed that R. massiliae was the most prevalent zoonotic V/TBP (19.5%), followed by E. canis (10.8%), Rickettsia sp. (7.5%), R. raoultii (6.7%), T. annulata (5.8%), D. immitis (5.8%), Wolbachia sp. (4.2%) and Ehrlichia sp. (3.3%), respectively. Among the screened tick species, most Rhipicephalus sanguineus sensu lato samples were found positive for V/TBP DNA (20/20,100%) followed by Rh. turanicus sensu stricto (13/20, 65%), Hyalomma dromedarii (8/20, 40%), Rh. haemaphysaloides (6/20, 30%), Hy. excavatum (2/20, 10%) and Rh. microplus (1/20, 5%). Co-occurrence of V/TBP was also detected in tick specimens (single V/TBP infection: 32 ticks; double and triple: 13 and 5 tick samples). The detected pathogens shared a phylogenetic relationship with similar isolates published in NCBI GenBank from Old and New World countries.
CONCLUSIONS: Ixodid ticks infesting dogs harbor a diverse array of V/TBPs including zoonotic agents from Pakistan. Furthermore, the presence of D. immitis in ticks that infest dogs raises the possibility that this parasite has either attained its dead-end host (i.e. the tick) while feeding on dogs or has expanded its range of intermediate/paratenic hosts. Further research work is needed to investigate the epidemiology and confirm the vector competence of screened tick species for these pathogens from Pakistan.