A suspected dengue fever outbreak occurred in 2010 at a solitary construction site in Shenzhen city, China. To investigate this epidemic, we used serological, molecular biological, and bioinformatics techniques. Of nine serum samples from suspected patients, we detected seven positive for dengue virus (DENV) antibodies, eight for DENV-1 RNA, and three containing live viruses. The isolated virus, SZ1029 strain, was sequenced and confirmed as DENV-1, showing the highest E-gene homology to D1/Malaysia/36000/05 and SG(EHI)DED142808 strains recently reported in Southeast Asia. Further phylogenetic tree analysis confirmed their close relationship. At the epidemic site, we also detected 14 asymptomatic co-workers (out of 291) positive for DENV antibody, and DENV-1-positive mosquitoes. Thus, we concluded that DENV-1 caused the first local dengue fever outbreak in Shenzhen. Because no imported case was identified, the molecular fingerprints of the SZ1029 strain suggest this outbreak may be due to vertical transmission imported from Southeast Asia.
A 24-year-old man born in Guizhou province was diagnosed with obstructive jaundice and bile duct stones in 2013. Four living trematodes were found during laparotomy and cholecystectomy. Based on the morphology and molecular genetics analysis of internal transcribed spacer and pcox1 genes of the flatworm specimens, the trematodes from the patient were confirmed to be Fasciola hepatica. This report provided the clinical and molecular diagnosis information on human fascioliasis, which is an emerging sanitary problem still ignored in China. Human fascioliasis constantly occurs due to climatic changes and frequency of human travel. Therefore, it deserves more attention from physicians working in both developing and developed countries.
Different miRNAs are involved in the life cycles of Schistosoma japonicum. The aim of this study was to examine the expression profile of miRNAs in individual S. japonicum of different sex before and after pairing (18 and 24 dpi). The majority of differential expressed miRNAs were highly abundant at 14 dpi, except for sja-miR-125b and sja-miR-3505, in both male and female. Moreover, it was estimated that sja-miR-125b and sja-miR-3505 might be related to laying eggs. sja-miR-2a-5p and sja-miR-3484-5p were expressed at 14 dpi in males and were significantly clustered in DNA topoisomerase III, Rap guanine nucleotide exchange factor 1 and L-serine/L-threonine ammonia-lyase. Target genes of sja-miR-2d-5p, sja-miR-31- 5p and sja-miR-125a, which were expressed at 14 dpi in males but particularly females, were clustered in kelch-like protein 12, fructose-bisphosphate aldolase, class I, and heat shock protein 90 kDa beta. Predicted target genes of sja-miR-3483-3p (expressed at 28 dpi in females but not in males) were clustered in 26S proteasome regulatory subunit N1, ATPdependent RNA helicase DDX17. Predicted target genes of sja-miR-219-5p, which were differentially expressed at 28 dpi in females but particularly males, were clustered in DNA excision repair protein ERCC-6, protein phosphatase 1D, and ATPase family AAA domaincontaining protein 3A/B. Moreover, at 28 dpi, eight miRNAs were significantly up-regulated in females compared to males. The predicted target genes of these miRNAs were significantly clustered in heat shock protein 90 kDa beta, 26S proteasome regulatory subunit N1, and protein arginine N-methyltransferase 1. To sum up, differentially expressed miRNAs may have an essential role and provide necessary information on clarifying this trematode's growth, development, maturation, and infection ability to mammalian hosts in its complex life cycle, and may be helpful for developing new drug targets and vaccine candidates for schistosomiasis.
Coxsackievirus A16 (CV-A16) of the genotypes B1a and B1b have co-circulated in mainland China in the past decades. From 2013 to 2017, a total of 3,008 specimens from 3,008 patients with mild hand, foot, and mouth disease were collected in the present study. Viral RNA was tested for CV-A16 by a real-time RT-PCR method, and complete VP1 sequences and full-length genome sequences of CV-A16 strains from this study were determined by RT-PCR and sequencing. Sequences were analyzed using a series of bioinformatics programs. The detection rate for CV-A16 was 4.1%, 25.9%, 10.6%, 28.1% and 12.9% in 2013, 2014, 2015, 2016 and 2017, respectively. Overall, the detection rate for CV-A16 was 16.5% (497/3008) in this 5-year period in Shenzhen, China. One hundred forty-two (142/155, 91.6%) of the 155 genotype B1 strains in the study belonged to subgenotype B1b, and 13 (13/155, 8.4%) strains belonged to subgenotype B1a. Two strains (CVA16/Shenzhen174/CHN/2017 and CVA16/Shenzhen189/CHN/2017) could not be assigned to a known genotype. Phylogenetic analysis of these two strains and other Chinese CV-A16 strains indicated that these two CV-A16 strains clustered independently in a novel clade whose members differed by 8.4%-11.8%, 8.4%-12.1%, and 14.6%-14.8% in their nucleotide sequences from those of Chinese B1a, B1b, and genotype D strains, respectively. Phylogenetic analysis of global CV-A16 strains further indicated that the two novel CV-A16 strains from this study grouped in a previously uncharacterized clade, which was designated as the subgenogroup B3 in present study. Meanwhile, phylogenetic reconstruction revealed two other new genotypes, B1d and B4, which included a Malaysian strain and two American strains, respectively. The complete genome sequences of the two novel CV-A16 strains showed the highest nucleotide sequence identity of 92.3% to the Malaysian strain PM-15765-00 from 2000. Comparative analysis of amino acid sequences of the two novel CV-A16 strains and their relatives suggested that variations in the nonstructural proteins may play an important role in the evolution of modern CV-A16.