Investigation On Infection Of Three Kinds Of Intestinal Protozoa In Beef Cattle In Some Areas Of Hebei Province

Cryptosporidium,Enterocytozoonbieneusi and Giardia lamblia are important zoonotic intestinal protozoal diseases,which can not only cause diarrhea of beef cattle,affect the production performance of beef cattle,restrict the development of economy,but also pose a threat to human health.At present,there are few reports on the genotype,host specificity and infection of these three intestinal protozoa in beef cattle population in Hebei region.We fromed April 2018 to December 2018 in Chengde,Cangzhou,Qinhuangdao,Shijiazhuang,Tangshan and Langfang six areas were collected 718 stool samples,respectively using nested PCR technology is based on the different genes to parts of Hebei beef Cryptosporidium,E.bieneusi and Giardia lamblia infection status,analyze and determine the population structure,and obtain the following results:1.Cryptosporidium was detected with 18 S rRNA gene,and the total infection rate was 9.2%(66/718)in 718 samples.The highest infection rate in Qinhuangdao was 12.0%,with no significant difference(P=0.242,P > 0.05).The highest infection rate was 11.8% in summer,with no significant difference among seasons(P=0.213,P > 0.05).Three cryptosporidium species were identified after sequencing of 66 positive samples.C.andersoni was the dominant species in our province,with the highest positive rate of 72.7%(8/66),followed by C.parvum(15.2%)(10/66)and C.muris(9.1%)(6/66).Among them,C.parvum is a zoonotic insect species,and it infection exists in Qinhuangdao,Chengde and Cangzhou.2.E.bieneusi was detected with ITS gene,and the total infection rate was 8.6%(62/718)in 718 samples.The highest infection rate was 10.6% in Qinhuangdao area,with no significant difference(P=0.263,P > 0.05).The highest infection rate was 11.0% in summer,with no significant difference among seasons(P=0.213,P > 0.05).The 62 positive samples were sequenced,and a total of 7 genotypes were identified after sequence analysis,among which Genotype J was the dominant genotype in the province,with a positive rate of 77.4%(48/62).Next,the infection rate of genotype BEB4 was 6.5%(4/62),CHC8 4.8%(3/62),EbpC,I and D 3.2%(2/62),and BEB6 1.6%(1/62).Genotypes D and EbpC are zoonotic genotypes,and there are infections of genotypes D and EbpC in Qinhuangdao.3.G.lamblia was detected with GDH gene,and the total infection rate was 5.2%(37/718)in 718 samples.Qinhuangdao had the highest infection rate 6.9%(15/217),with no significant difference(P=0.263,P > 0.05).The highest infection rate was 7.5% in summer,with no significant difference among seasons(P=0.213,P > 0.05).The 37 positive samples were sequenced,and two cluster types were detected.Cluster E was the dominant species in our province,with the highest positive rate of 81.1%(30/37)and cluster A was 19.0%(7/37).Among them,cluster A is a zoonotic insect species,and the infection of cluste A exists in Qinhuangdao and Cangzhou.