| The goat is an important economic animal and has an important position in the development of the animal husbandry in our country. Three goat species, namely Northern Shaanxi white cashmere goats, Saanen dairy goats, North Shaanxi black goats, are important goat breeds in China, and are also dominant economic animals in Shaanxi province. However, with the continuous expansion of the goat industrial scale, the goat disease has gradually become an important factor hindering the development of this industry. Among these diseases, the microsporidiosis is not only harmful to the health of goats, some microsporidia species also can cause human diseases. Enterocytozoon bieneusi is the main pathogen of microsporidiosis in animals and humans, and can cause self-limited diarrhea in immunocompetent host, and lead to severe and even life-threatening diarrhea in immunocompromised or immunodeficient hosts. Since E. bieneusi not only affects the animal production performances and economic values, but also has the zoonotic risk to threat the human health, the present study was to investigate the infection status and genotypes of E. bieneusi in different production categories of goats in Shaanxi province, providing the foudamental data for the prevention and control of microsporidiosis of humans and animals.In the present study, the infection rates and genotypes of E. bieneusi in goats from partial Shaanxi province were firstly determined using the nested PCR based on the internal transcribed spacer(ITS) gene. Then, the population genetics for isolates obtained were analysed using multilocus genotyping tools based on loci of micro- and minisatellites. Finally, the genetic diversity and zoonotic potential of E. bieneusi from different production categories of goats were evaluated.The results in this study indicated that, of goats in the three different production categories, the highest infection rate(32.9%) was observed in saanen dairy goats, which was significantly higher than cashmere(15.9%, P<0.05) and meat(15.0%, P<0.05) goats. Among different age groups, the highest infection rate(33.3%) was detected in goats of 3~6 months, followed by goats of 0~2 months(24.4%) and7~12 months old(17.4%). The lowest infection rate(15.1%) was seen in adult(>12 months) goats. Within 122 E. bieneusi-positive isolates obtained, four different genotypes were identified, including three known genotypes(BEB6, CHG1, CHG2) and one novel genotype SX1. The amplifications based on micro-(MS1, MS3, MS7) and mini-satellite loci(MS4) showed that, the respective amplification efficiencies in loci MS1, MS4 and MS7 were 28.7%(35/122), 18.0%(22/122), 50.8%(62/122), but no amplications were detected in the locus MS3. The nucleotide sequences analysis indicated that, 16, 9 and 18 genotypes were found in all positive samples for loci MS1, MS4 and MS7, respectively, forming fourteen four MLGs. Among them, the amplification efficiencies of three loci in 50 positive samples of cashmere goats were 10.0%(5/50), 14.0%(7/50) and 90.0%(45/50), respectively, belonging to three, three and ten genotypes, and five MLGs. The amplification efficiencies of 56 positive samples of dairy goats in three loci were 28.6%(16/56), 19.6%(11/56) and 8.9%(5/56), grouping into four, four, one genotypes, and seven different MLGs. The amplification efficiencies of three loci of 16 positive samples of black goats were 81.3%(13/16) and 25.0%(4/16), 75.0%(12/16), clustering into 9, 2, 7 genotypes, and two MLGs.Collectively, this study indicated the existence of the infection of E. bieneusi in different production categories of goats in partial areas of Shaanxi, and zoonotic genotypes of E. bieneusi in dairy goats. The genetic analysis revealed the host specificity for the newly discovered genotype SX1. In addition, the genetic diversity of E. bieneusi was found in goats in Shaanxi province in this study, and 14 MLGs were presented. These findings suggest that comprehensive control measures would be developed for the control of E. bieneusi infection in Shaanxi province, and effective measures should be applied to prevent its transmission to humans. |
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