Prevalence and molecular characterization of Cryptosporidium in captive-bred Mustela putorius furo in Jiangsu Province / 中国血吸虫病防治杂志

Objective To investigate the prevalence and molecular features of Cryptosporidium in captive-bred Mustela putorius furo in Jiangsu Province.. Methods A total of 290 fresh stool samples were collected from a ferret farm in Jiangsu Province on May 2017, and the small subunit rRNA (SSU rRNA) gene of Cryptosporidium was amplified in stool samples using nested PCR assay. The actin, cowp and gp60 genes were amplified in positive samples and sequenced to characterize Cryptosporidium species/genotypes. Results A total of 18 stool samples were tested positive for Cryptosporidium SSU rRNA gene, with a detection rate of 6.2%. Sequence and phylogenetic analyses of SSU rRNA, actin and cowp genes characterized Cryptosporidium isolated from captive-bred ferrets as Cryptosporidium sp. ferret genotype. In addition, gp60 gene was amplified in 10 out of 18 stool samples tested positive for Cryptosporidium. Conclusions Cryptosporidium is widely prevalent in captive-bred ferrets in Jiangsu Province, and Cryptosporidium sp. ferret genotype is the only Cryptosporidium genotype in ferrets.

Prevalence and molecular characterization of Cryptosporidium spp. in Père Davids deer (Elaphurus davidianus) in Jiangsu, China / Prevalência e caracterização molecular de Cryptosporidium spp. no cervo de Père David (Elaphurus davidianus) em Jiangsu, China

Abstract Cryptosporidium is a zoonotic parasite that causes diarrhea in a broad range of animals, including deer. Little is known about the prevalence and genotype of Cryptosporidium spp. in Père David's deer. In this study, 137 fecal samples from Père David's deer were collected between July 2017 and August 2018 in the Dafeng Reserve and analyzed for Cryptosporidium spp. by nested-PCR based on the small subunit ribosomal RNA (SSU rRNA) gene, followed by sequence analyses to determine the species. The 60 kDa glycoprotein (gp60) gene was used to characterize Cryptosporidium spp. Among 137 samples, 2 (1.46%) were positive for Cryptosporidium spp. according to SSU rRNA gene sequencing results. Both samples belonged to the Cryptosporidium deer genotype, with two nucleotide deletions and one nucleotide substitution. The prevalence data and molecular characterization of this study provide basic knowledge for controlling and preventing Cryptosporidium infections in Père David's deer in this area.

Resumo Cryptosporidium é um parasita zoonótico que causa diarreia em uma ampla gama de animais, incluindo veados. Pouco se sabe sobre a prevalência e o genótipo de Cryptosporidium spp. no cervo de Père David. Neste estudo, 137 amostras fecais do cervo de Père David foram coletadas entre julho de 2017 e agosto de 2018, na Reserva Dafeng, e analisadas para Cryptosporidium spp. por nested-PCR baseado no gene do RNA ribossômico da subunidade pequena (SSU rRNA), seguido de análises de sequências para determinar as espécies. O gene da glicoproteína de 60 kDa (gp60) foi utilizado para caracterizar Cryptosporidium spp. Dentre as 137 amostras, 2 (1,46%) foram positivas para Cryptosporidium spp. de acordo com os resultados do sequenciamento gênico de SSU rRNA. Ambas as amostras pertenciam ao genótipo do cervo Cryptosporidium, com duas deleções nucleotídicas e uma substituição nucleotídica. Os dados de prevalência e a caracterização molecular deste estudo fornecem conhecimentos básicos para controlar e prevenir infecções por Cryptosporidium nos cervos de Père David nessa.

Progress of researches on Blastocystis infections in humans and animals in China / 中国血吸虫病防治杂志

Blastocystis is a unicellular, anaerobic, intestinal protozoan that infects humans and a variety of animals, which is widely prevalent across the world. Blastocystis infections have been detected in healthy populations, children, students, outpatients and inpatients, as well as diarrhea patients in China. High prevalence of Blastocystis infections has been reported in immunocompromised patients, and relatively high prevalence was seen in individuals living in Guangxi and Yunnan regions. Based on the small subunit ribosomal RNA (SSU rRNA) gene sequence, a total of 17 subtypes (ST1 to ST17) of Blastocystis have been characterized until now, among which ST1 to ST9 and ST12 infect humans and animals, and ST10 to ST17 only infect animals. In China, ST1 to ST3 are predominant human Blastocystis subtypes, and ST1/ST3, ST1/ST2 and ST2/ST3 mixed infections have been also identified. This review mainly describes the epidemiology and genotypes of Blastocystis in humans and animals in China.

Real-time PCR: Benefits for Detection of Mild and Asymptomatic <i>Giardia</i> Infections

The majority of <i>Giardia</i> infections are transmitted by the fecal-oral route and cause giardiasis. Children who live in crowded conditions or low socio-economic areas are the risk group for <i>Giardia</i> infection. Interestingly, most of them are asymptomatic or only mildly infected and can shed the <i>Giardia</i> cysts in the environment. Thus, the diagnosis of <i>Giardia</i> infection in asymptomatic or mild infection plays an important role in achieving control of <i>Giardia duodenalis</i> transmission. The objective of this study was to examine parasitic infections using microscopy and to develop a real-time PCR method for detection of <i>Giardia</i> infection in the stool samples of children living on the Thai-Myanmar border. Both species-specific primers and fluorescent labeled <i>G. duodenalis</i> probe were designed using small-subunit ribosomal RNA (<i>ssrRNA</i>). The results showed that 10 (7.69%) and 40 (30.77%) of 130 stool samples were positive for <i>G. duodenalis</i> by microscopy and real-time PCR respectively. Only 3 out of 9 liquid stools revealed <i>G. duodenalis</i> positive using microscopy, but all of them were <i>G. duodenalis</i>-positive using real-time PCR. The detection limit of real-time PCR for <i>G. duodenalis</i> was 0.1 pg/25 µl reaction. It can detect both mild and asymptomatic <i>Giardia</i> infections in children living on the Thai-Myanmar border.

Phylogenetic Relationships of the Polyporaceae Based on Gene Sequences of Nuclear Small Subunit Ribosomal RNAs

The Polyporaceae is a chaotic mass of genera having poroid hymenophores in the Aphyllophorales. To classify the Polyporaceae into more natural groups, phylogenetic analyses were performed using nuclear small subunit ribosomal DNA sequences. Thirty-six species from the families of the Polyporaceae, the Hymenochaetaceae, the Ganodermataceae, the Corticiaceae, the Bondarzewiaceae, the Meruliaceae, the Steccherinaceae and the Lentinaceae were phylogenetically compared. By performing maximum parsimony analysis, seven phylogenetically meaningful groups were identified and discussed. The hyphal system, presence or absence of clamps, and the type of rot were found as important characters in defining the groups. Each group was phylogenetically significant enough to be a core member of each family when the Polyporaceae was split into smaller and more natural families.

Homology of 18S small subunit ribosomal RNA gene among species and strains of Schistosoma and sensitivity of PCR assay to detect single cercaria / 中国血吸虫病防治杂志

Objective To research the homology of 18S small subunit ribosomal RNA(18S-rRNA) gene about Chinese Mainland and Philippine strains of Schistosoma japonicum,and Schistosoma mansoni,and the possibility to establish the PCR assay based on the gene for detecting the cercaria in a low density level. Methods The genomic DNAs of Chinese Mainland and Philippine strains of S.japonicum,and S.mansoni were extracted. The PCR assay was used to detect the identical target DNA elements in the above genome team and the homology of their genes was compared. The single cercaria was respectively treated with the method of heating in boiling water,the method of treating with ammonia and the method of treating with NaOH,HCl and ethanol,and the single treated cercaria and the single cercaria without treating were used as the templates to amplify the target DNA by using the PCR assay,and the detection rates of the PCR assay to detect the single cercaria treated with the different methods were calculated and compared. Results With the genomic DNAs of Chinese Mainland and Philippine strains of S.japonicum and S.mansoni as the templates,the target DNA element of which sequence length was 469 bp was all amplified by PCR. The target DNA was all amplified by PCR to the single cercaria treated with ammonia and the method of treating with NaOH,HCl and ethanol. However,only 50 percent of specimens of the single cercaria without treating and the single cercaria treated with the method of heating in boiling water were amplified to the target DNA by PCR. Conclusions The 18S-rRNA gene has the general homology among the species and strains of Schistosoma. The sensitivity of the PCR assay to detect the low density cercaria treated with ammonia or the method of treating with NaOH,HCl and ethanol is higher than that of the single cercaria without treating or treated with the method of heating in boiling water.