The Molecular Prevalence Research Of Three Important Enteric Protozoa In Children And Companion Animals From Hei Longjiang Province

Parasitic diseases contribute significantly to the burden of infectious diseases worldwide. While most infections and death from parasitic diseases affect people in developing countries, they also cause significant illness in developed countries. In 2004, the WHO reported the diarrheal disease affected far more individuals than any other illness. Several species of enteric protozoa are associated with diarrheal illnesses in humans, with some causing severe debilitating illness, especially in immunosuppressed populations. Cryptosporidium spp., Giardia intestinalis, Enterocytozoon bieneusi are three important pathogeny that causing humans and animals diarrhea. They commonly result in persistent and life-threatening diarrhea in immunocompromised populations(especially humans or animals with young age and HIV-positive patients) but selflimiting diarrhea in immunocompetent hosts. Therefore, people pay amount attention to them.In this study, 255 children feces from Harbin and Daqing, 319 companion animals(mainly cats and dogs) feces(of which 52 from cats, 267 from dogs) from Harbin, Daqing and Qiqihar were amplified by nested PCR for Cryptosporidium spp., Giardia intestinalis, E.bieneusi. Through amplifying small subunit ribosomal RNA(SSU r RNA) of Cryptosporidium spp. showed the infect rate of Cryptosporidium spp. in cat and dog were 3.8%(2/52) and 2.2%(6/267). C.felis(n=1) and C.parvum(n=1) was detected in 52 cats, with an infect rate of 1.9%(1/52) respectively; while C.canis(n=5) and C.ubiquitum(n=1) was detected in 267 dogs, the infect rate of C.canis was 1.9%(5/267), C.ubiquitum was 0.4%(1/267). There were no Cryptosporidium spp. positive samples in children feces. Using ITS(internal transcribed spacer) amplifying for E.bieneusi showed the total infect rate of children was 7.5%(19/255), in which Harbin was 11.9%(16/134) and Daqing was 2.5%(3/121). Female infect rate was 8.4%(11/131), whereas male was 6.5%(8/124). The sample with diarrhea and non-diarrhea infect rates were 25%(1/4) and 7.2%(18/251). Therefore, E.bieneusi may play an important role in causing diarrhea. 8 genotypes were found in children samples, with 3 known genotypes, CS-4(n=2), Ebp C(n=11), Henan-IV(n=3) and 5 novel genotypes named NEC1 to NEC5. Among them, Henan-IV and NEC1, Ebp C and NEC4 detected mixed infect in Harbin hospital and primary school respectively. In companion animals, 21 positive samples including 18 dogs and 3 cats, 8 genotypes were detected, among them, D, Ebp C, IV and Pt Eb IX were the known genotype, the other 4 novel genotypes named NED1 to NED4. Phylogenetic analysis showed genotype D(n=1), Ebp C(n=2), NED1(n=1) and NED2(n=1) from dogs had the potential of zoonosis, and genotype NED3(n=1), NED4(n=1) and Pt Eb IX(n=14) were host-adapted. The total mixed infect was 3, 2 mixed infect(Ebp C and NED1, Pt Eb IX and NED3) were found in samples from Harbin pet hospital, the other(Pt Eb IX and NED4) existed in Harbin pet market. We also found two genotypes D(n=2) and IV(n=1) which can cause human microsporidiosis in three cat samples in Harbin pet market. Genotype Ebp C existed both in humans and companion animals.For detecting Giardia intestinalis we also used the nested-PCR targeted TPI(triose phosphate isomerase) gene. There were no Giardia intestinalis positive in children samples. In companion animals, the infect rate of dogs and cats were 4.5%(12/267) and 1.9%(1/52). Three assembles(assemble F, assemble C and assemble E) were detected. Assemble F was found in a cat while assemble C and assemble E were found in 12 dogs.The Cryptosporidium spp. species, C.canis, C.felis and C.parvum; genotypes D, Ebp C andIV of E.bieneusi and assemble C of Giardia intestinalis found in companion animals in our studyalso reported in China can infect humans. Genotypes D, Ebp C and IV of E.bieneusi and theCryptosporidium spp. species C.canis, C.parvum and C.ubiquitum also existed in wastewater inChina. All of these showed companion animals may be reservoir host of human Cryptosporidiosis,microsporidiosis, Giardiasis and the potential source of water pollution, they were risk factor ofhuman disease and they had the potential to transmit zoonosis to humans. Therefore, do researchin the prevalence state and genotypes distribution of these three protozoa will have significantroles in government to establish prevention measures, control infect and prevent the breakout ofzoonotic disease.