Identification Of Hard Tick Species In Some Areas Of Shaanxi Province And Detection Of Its Carrying Pathogens

Hard ticks are able to carry and spread a wide range of pathogens including bacteria,viruses,and protozoa,posing a great potential threat to the health of humans and animals alike worldwide.Until now,relatively few studies have been conducted on the distribution of ticks and the pathogens they carry.This study,therefore,aims to figure out and dig deep into different species of hard ticks in Shaanxi Province and the pathogens they carry,providing data support for the improvement of the prevention and control of ticks-borne diseases and for the future in-depth researches as well.From March 2017 to September 2020,the ticks on the body surface of hedgehogs,dogs,cattle and the like were collected from a total of four regions in Shaanxi Province,namely,Xi’an,Xianyang,Ankang,and Hanzhong.And then morphological identification of ticks and molecular biological identification based on mitochondrial 12 S r DNA and 16 S r DNA genes were employed for the identification of different tick species.Besides,PCR detection technology was used for the detection of Rickettsia,Babesia,Theileria,Hepatozoon,Anaplasma phagocytophilum and other pathogens carried by ticks based on different genes.The results are as follows:1.A total of 129 ticks samples were collected for this experiment.After preliminary identification of morphology and molecular biology methods based on 12 S r DNA and 16 S r DNA genes,a total of five species of ticks were identified,i.e.,Rhipicephalus microplus,Haemaphysalis longicornis,Ixodes acutitarsus,Haemaphysalis flava and Haemaphysalis campanulata.2.After amplifying and sequencing 129 tick samples by PCR,the results showed that these tick species carry a total of seven pathogens,namely,Candidatus Rickettsia jingxinensis,Rickettsia japonica,Babesia bigemina,Babesia bovis,Theileria orientails,Anaplasma phagocytophilum,and Hepatozoon canis.The pathogens carried by various tick species are listed as follows: R.microplus carries five pathogens,including B.bovis,B.bigemina,T.orientalis,Ca.R.jingxinensis,H.canis;H.longicornis carries three species of pathogens which are T.orientalis,Ca.R.jingxinensis,and H.canis;H.flava carries two species of pathogens,namely,R.japonica and A.phagocytophilum;H.campanulata carries two species of pathogens,T.orientails and Ca.R.jingxinensis;I.acutitarsus only carries one pathogen,which is A.phagocytophilum.3.The mixed carrier of various pathogens exists in different tick species.Among them,the mixed carrying rate of H.canis and Ca.R.jingxinensis in H.longicornis is 12.4%,it is2.3% for R.japonica and A.phagocytophilum in H.flava.while the mixed carrying rate of two and three pathogens in R.microplus is 47.3%.To sum up,there are five species of ticks in Shaanxi Province,namely,H.longicornis,R.microplus,H.flava,H.campanulata and I.acutitarsus.The pathogens carried by these ticks contain at least seven different pathogens such as R.japonica,Ca.R.jingxinensis,B.bigemina,B.bovis,T.orientalis,H.canis,and A.phagocytophilum,etc.It is possible that a single tick carries a mixture of two or three pathogens.