ABSTRACT
Cyclospora cayetanensis is a foodborne and waterborne pathogen that causes endemic and epidemic human diarrhea worldwide. A few epidemiological studies regarding C. cayetanensis infections in China have been conducted. During 2013, a total of 291 stool specimens were collected from patients with diarrhea at a hospital in urban Shanghai. C. cayetanensis was not detected in any of the stool specimens by traditional microscopy, whereas five stool specimens (1.72%, 5/291) were positive by PCR. These positive cases confirmed by molecular technology were all in the adult group (mean age 27.8 years; 2.94%, 5/170) with watery diarrhea. Marked infection occurred in the rainy season of May and July. Sequence and phylogenetic analyses of the partial 18S rRNA genes of C. cayetanensis isolated showed intra-species diversity of this parasite. This study showed, for the first time, that C. cayetanensis is a pathogen in outpatients with diarrhea in Shanghai, albeit at a low level. However, the transmission dynamics of this parasite in these patients remain uncertain.
Subject(s)
Adolescent , Adult , Female , Humans , Male , Middle Aged , Young Adult , China , Epidemiology , Cyclospora , Genetics , Cyclosporiasis , Epidemiology , Diarrhea , Parasitology , Feces , Parasitology , Outpatients , Phylogeny , Polymerase Chain Reaction , RNA, Ribosomal, 18S , Retrospective StudiesABSTRACT
Objective To study the structural features and characteristics of a novel gene Schistosoma japonicum 79(Sj79), and observe its effect of RNA interference(RNAi),so as to provide the experimental basis for its further function study and mechanism study of anti reproductive development of schistosome. Methods The gene structure and characteristics of Sj79 were analyzed by bioinformatics methods. Then the expressions of Sj79 messenger RNA(mRNA)during the different develop?mental stages of schistosome were analyzed and the effects of RNAi silencing were observed by the soaking method. The tran?scriptional levels of Sj79 after RNAi were detected by real time PCR. Results The open reading frame of Sj79 contained 696 base pairs with an exon structure. The gene had obvious stage specificity,and its transcriptional level in mature female worms was the highest. After soaking for 3 d,the Sj79 mRNA level[(41.0 ± 12.3)%]in the siRNA?1 group with low dosage(20 nmol/L) was lower than that in the siRNA?NC group[(103.2 ± 14.4)%],the difference was statistically significant(t=3.28,P<0.05). When with high dosage(200 nmol/L ),both the Sj79 mRNA levels in the siRNA?1 group[(15.8 ± 10.9)%]and siRNA?2 group [(11.1 ± 8.8)%]were significantly lower than that in the siRNA?NC group[(100.1 ± 6.3)%](t=13.44,27.84,both P<0.01). After soaking for 7 d,only the Sj79 mRNA levels in the siRNA?1group[(43.4 ± 4.5)%]and siRNA?2 group[(62.5 ± 5.4)%]with low dosage were lower than that in the siRNA?NC group[(100.4 ± 5.2)%],and the differences had statistical sig?nificance(t=8.33,5.07,both P<0.01). Conclusion Through this study,we have improved the mRNA sequence and genom?ic information of Sj79 gene,and understood its structural features,as well as selected out two effect fragments siRNA?1and siR? NA?2 which will provide the basic evidences for the further study on egg laying interference of the female adult worm of schisto?some in vitro.
ABSTRACT
<p><b>OBJECTIVE</b>Cryptosporidium spp. are prevalent globally and sheep are an important zoonotic reservoir. Little data regarding the rates of Cryptosporidium infections in ovines in China are available. This study assessed the prevalence of Cryptosporidium spp. in pre-weaned ovines from Aba Tibetan and Qiang Autonomous Prefecture in the Sichuan province of China.</p><p><b>METHODS</b>A total of 213 fecal samples were collected from pre-weaned ovines and were examined microscopically (following modified acid fast staining). In addition, 18S rRNA genetic sequences were amplified from fecal samples by nested PCR and phylogenetically analyzed.</p><p><b>RESULTS</b>The prevalence of Cryptosporidium in the collected samples was at 14.6% (31/213) and four isolates identified by PCR belonged to the Cryptosporidium cervine genotype (Cryptosporidium ubiquitum) demonstrating that this species was the primary sheep species found in sheep in China.</p><p><b>CONCLUSION</b>The present study suggested that the high incidence of Cryptosporidium in sheep poses a significant public health threat and that surveillance practices must be established to prevent zoonotic disease of humans.</p>
Subject(s)
Animals , China , Cryptosporidium , Genetics , Feces , Parasitology , Oocysts , Microbiology , Polymerase Chain Reaction , Sheep , WeaningABSTRACT
Objective To obtain novel vaccine candidate antigens against Schistosoma japonicum. Methods S. japonicum schistosomula cDNA library was screened by using sera of Microtus fortis that was naturally resistant to schistosomiasis. The positive clones were transformated into Escherichia coli BM25.8, E. coli clones containing the plasmid cultured in LB, and then selected for plasmid extraction, the plasmid DNA was digested by EcoRⅠand Hind Ⅲ, and analysed by agarose gel electrophoresis. The positive clones were also sequenced and the data were analysed through the internet Nucleotide BLAST software of NCBI and Expert Protein Analysis system of GeneRunner and HNN. Results Twelve positive clones were obtained after repeatedly immunoscreening the library and their sizes ranged from 300 bp to 1100 bp. Two novel genes (named as Sj-sMf1 and Sj-sMf2) with complete ORF were obtained. The deduced protein of Sj-sMf1 consisted of 93 amino acids while Sj-sMf2 consisted of 61 amino acids. Sj-sMf1 protein predicted containing one cAMP phosphorylation site and Casein kinase C phosphorylation site, respectively. Sj-sMf1 protein predicted containing one Casein kinase C phosphorylation site and two Protein kinase C phosphorylation sites. Conclusion Two novel genes predictably encoding unknown proteins are obtained from immunoscreening of Schistosoma japonicum schistosomula cDNA library by M. fortis sera.