Molecular Epidemiological Investigation Of Cryptosporidium In Dairy Cows In Parts Of Inner Mongolia

Animal husbandry is one of the pillar industries in the economy of Inner Mongolia Autonomous Region.Cryptosporidium infection will reduce the production performance of dairy cows,especially cause serious diarrhea and even death of calves,and cause huge losses to the breeding industry.In 1998,the World Health Organization added human cryptosporidiosis to the suspected indicators of AIDS,which was identified as an important new parasitic disease by China’s health department in 2003.In addition,there is no effective vaccine and drug to prevent Cryptosporidium infection,and the systematic research of cow Cryptosporidium in Inner Mongolia autonomous region tends to be blank.In conclusion,it is very necessary to investigate and study the infection of Cryptosporidium in dairy cows in Inner Mongolia Autonomous Region and assess whether there is a risk of infection to humans.In order to have a clearer understanding of the infection rate,species and gene subtypes of Cryptosporidium in dairy cows in Inner Mongolia Autonomous Region.In this study,Cryptosporidium was investigated in dairy cows of large-scale farms and farmers in some areas of Inner Mongolia by using pathogenic and molecular biological methods.Based on the SSU r RNA gene of Cryptosporidium parvum and the gp60 gene of Cryptosporidium parvum,nested PCR amplification,sequencing and sequence analysis were performed on 505 fresh fecal samples collected from dairy cows with diarrhea and non diarrhea at different ages.The amplified products were digested with restriction endonuclease to determine the infection status,genotype and gene subtype of Cryptosporidium parvum.The results showed that the total infection rate of Cryptosporidium in dairy cows in Inner Mongolia Autonomous Region was 29.90%(151/505),there was a significant difference between the infection rates of four different farms(22.50%～39.29%)(P<0.05),and there was a very significant difference between the infection rates of four different month groups(18.50%～43.81%)(P<0.001).The infection rate of Cryptosporidium in diarrhea dairy cows(37.67%,55/146)was significantly higher than that in non diarrhea dairy cows(26.74%,96/359)(P<0.05);There are four Cryptosporidium species,C.parvum,C.bovis,C.ryanae and C.andersoni,and mixed infection among the four species in dairy cows in Inner Mongolia Autonomous Region.C.bovis and C.andersoni are the dominant species in dairy cows in Inner Mongolia Autonomous Region;The subtype of Cryptosporidium parvum infected by dairy cows in Inner Mongolia Autonomous Region is IId A19G1 subtype.This study is the first systematic study on Cryptosporidium in dairy cows in Inner Mongolia Autonomous Region.It is the first time that dairy cows in Inner Mongolia Autonomous Region are infected with 4 kinds of Cryptosporidium and have mixed infection,The genotypes of Cryptosporidium parvum in dairy cows in Inner Mongolia Autonomous Region were identified for the first time.The results laid a foundation for the prevention and control of cryptosporidiosis.