| ABSTRACT:Microsporidia is unicellular eukaryotic, obligate intracellular protozoan parasite that infects a broad range of invertebrates and vertebrates. It is also a kind of zoonotic pathogen. It includes more than1400species that can be divided into about150generas. And among them, at least14species in8generas can infect human. Microsporidia has been recognized as an important opportunistic pathogen with the prevalent of AIDS since the1980s. The immunocompromised people and those with normal immune function all can be infected by Microsporidia. After the people and animals with normal immune system are infected with this pathogen, they just show temporary symptoms or latent infection. While the patients with defective immunity, low immunity and suppressed immunity, especially the people with AIDS, once they are infected with this pathogen, they will develop fatal diarrhea, which is one of the major risk factors of AIDS. In addition, Microsporidia can cause damage to urinary system and respiratory system and many other diseases such as keratitis, encephalitis and myocarditis. As a new infectious disease, Nosema has caused a worldwide public health problem. It has been on the list of the second class of potentially dangerous microbes by the U.S. National Institute of Allergy and Infectious Diseases. In this paper, a comprehensive exploration was conducted to investigate the epidemiology and genetic characteristics of Nosema in pigs, sheeps and goats in Henan province. This research will provide basic reference for later related scholars and for the control and treatment of this disease.1. In order to understand the infection and impact of swine intestinal parasites in some areas of Henan province and formulate a prevention program scientifically to guide the prevention of animal intestinal parasites reasonably,462fresh fecal samples were collected from seven cities of Henan province and Beichuan city of Sichuan province during September2012and May2013, and then all the samples were examined by Lugol’s iodine staining, saturated sugar flotation technique and Mike Maas counting method. The results showed that8species of intestinal parasite were detected in402samples and the overall infection rate was61.93%. The parasites are Coccidia, Cryptosporidium, Giardia, Whipworm, Round worm, Nematodes, Balantidium coli and Entamoeba. Among them, Entamoeba had the highest infection rate of44.81%. The infection intensity of Coccidia and Nematodes were<200-4600and<200-600respectively.2. To learn the infection of Microsporidia in swines and their molecular characteristics, nested PCR was used to detect the fecal specimens. the results manifested that120positive samples were found in462samples, and the infection rate was25.97%. they are all Microsporidia. There were differences of infection rates of Microsporidia in swines with different ages and different feeding modes. The infection rates of different ages of swines were24.07%,21.13%,18.52%,12.90%.8.33%for fattening pigs, sows, weaners, suckling pigs, boar respectively. The infection rate of Microsporidia in the small specialist was42.15%, which was higher than the backyard and the scale, the infection rates of which were16.08%and3.13%respectively. Zhongmu city of Henan province had the highest prevalence of Pythagorean Nosema, the infection rate was56.41%.After the positive samples were sequenced and blasted,6sequences were obtained. And6other sequences were downloaded from NCBI. The homology of these12sequences was analyzed and the molecular phylogenetic tree was conducted using Clustal XI.81. Phyloip3.64, DNAstar4.0. The results showed that5genotypes of Pythagorean Nosema were found in pigs. They were F, PigEBITS5, EbpD, Type IV and EbpC/E/Peru4/WL13). Among them, genotype EbpC and Type IV can also be found in human. So there is a potential risk that the two genotypes may be zoonotic. There was another new genotype, which had the closest relationship with humanized genotype Type IV. Their homology was99.7%and there was just one base that was different.3. Nested PCR was used to detect the fecal specimens to detect the infection of Microsporidia and molecular characteristics of them in goats. The results manifested that74positive samples were found in802samples, and the infection rate was9.23%. The infection rates of Microsporidia in goats of different ages and different feeding modes varied. The infection rate in sheeps was6.93%, which was lower than that in backyard which was12.35%. The infection rate m young sheeps was10.34%which was higher than adult sheep which was7.62%. The infection rate in July to September was12.84%which was higher than that of October to December. The infection rate in putting sheeps was13.99%which was higher than domestic sheeps that was6.59%. After the positive samples were sequenced and blasted,6sequences were obtained. And6other sequences were downloaded from NCBI. The homology of these12sequences was analyzed and the molecular phylogenetic tree was conducted using Clustal X1.81, Phyloip3.64, DNAstar4.0. The results showed that3genotypes of Pythagorean Nosema were found in sheeps and goats. They were BEB6. EbpC/E/Peru4/WL13and D.Among them. genotype EbpC and D can also be found in human. So there is a potential risk that the two genotypes may be zoonotic. What’s more, two new genotypes were found, one of them had close relationship with genotype BEB6with homology of94.4%and another was on a separate branch.This was the first survey of epidemiology and genetic characteristics of Microsporidia in swines, sheeps and goats in Henan province. And the results indicated that the homology among Microsporidia found in infected swines, goats and3genotypes seprated from human was up to100%. These stated that the Microsporidia isolated from swines and goats may have a high risk to be zoonotic. So it is fairly important to research the Microsporidia in further for the public health. |
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