Characterization of Full-Length Enterovirus 71 Strains from Severe and Mild Disease Patients in Northeastern China

Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Poland
PLoS ONE (Impact Factor: 3.23). 03/2012; 7(3):e32405. DOI: 10.1371/journal.pone.0032405
Source: PubMed


Human enterovirus 71 (EV71)-associated hand, foot, and mouth disease (HFMD) has been a leading cause of childhood infection in China since 2008. Epidemic and molecular characteristics of HFMD have been examined in many areas of China, including the central and southern regions. However, clinical and genetic characterization of EV71 in the northeastern region of China is scarce. In this study, a series of analyses were performed on seven full-length EV71 sequences from HFMD patients who had either severe or mild disease. We have determined that these seven circulating EV71 viruses from Changchun, China are actually complex recombinant viruses involving multiple type A human enterovirus (HEV). Classified as EV71 subtype C4 (EV71 C4), these Changchun EV71 viruses contain genetic recombination events between the CA4, CA5, EV71B4 and EV71C1 strains. Most of the structural protein region (P1) of these viruses resembled that of the prototype EV71 C1 strains. The non-structural protein domains (P2 and P3) showed a high degree of similarity with CA4, CA5 and EV71 B4 in different regions. The 5'UTR had unclassified recombination,while partial 3D region of these viruses showed a high degree of similarity to CA16. Phylogenetic analysis of full-length or partial sequences of isolates from severe or mild disease patients in Changchun always formed a single cluster in various phylogenetic analyses of different genomic regions, suggesting that all seven strains originated from one single common ancestor. There was no correlation between viral genomic sequence and virulence. Thus, we found that circulating recombinant forms of EV71 are prevalent among HFMD patients in Northeastern China. The existence of a unique cluster of EV71 related viruses in Northeast China has important implications for vaccine development that would address the increasing prevalence of HFMD.

Download full-text


Available from: Wenyan Zhang
  • Source
    • "Such cross-reactive NtAb responses are important for vaccine development. Because serum samples were collected from young children (aged <5 years) in Changchun (northeastern region of China, 2012) and Luoyang (Central Plains region of China, 2008), and EV71-C4a was the major epidemic strain in China in recent years [19], [41], [42], the results suggest that the C4a subgenotype could induce cross-reactive NtAbs against different EV71 subgenotypes in these patients. In screening of the patients' sera with the neutralization assay, we also found that trends in the NtAb titers of Luoyang-294 and -301 against EV71 pseudoviruses of different subgenotypes were more similar to those of the Changchun samples, but different from those of other Luoyang samples. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Hand, foot and mouth disease, associated with enterovirus 71 (EV71) infections, has recently become an important public health issue throughout the world. Serum neutralizing antibodies are major indicators of EV71 infection and protective immunity. However, the potential for cross-reactivity of neutralizing antibodies for different EV71 genotypes and subgenotypes is unclear. Here we measured the cross-reactive neutralizing antibody titers against EV71 of different genotypes or subgenotypes in sera collected from EV71-infected children and vaccine-inoculated children in a phase III clinical trial ( Identifier: NCT01636245) using a new pseudovirus-based neutralization assay. Antibodies induced by EV71-C4a were cross-reactive for different EV71 genotypes, demonstrating that C4a is a good candidate strain for an EV71 vaccine. Our study also demonstrated that this new assay is practical for analyses of clinical samples from epidemiological and vaccine studies.
    Full-text · Article · Jun 2014 · PLoS ONE
  • Source
    • "The enterovirus sequencing strategy used has been previously described [23]. Extraction of total RNA from throat swabs was performed using TRIzol Reagent (Invitrogen) according to the manufacturer’s instructions. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Human enteroviruses (HEV) have been linked to hand, foot, and mouth disease (HFMD) in the Pacific and Southeast Asia for decades. Many cases of HFMD have been attributed to coxsackievirus A16 (CV-A16, CA16), based on only partial viral genome determination. Viral phenotypes are also poorly defined. Herein, we have genetically and phenotypically characterized multiple circulating CV-A16 viruses from HFMD patients and determined multiple full-length sequences of these circulating viruses. We discovered that the circulating CV-A16 viruses from HFMD patients are genetically distinct from the proto-type CV-A16 G10. We have also isolated circulating CV-A16 viruses from hospitalized HFMD patients and compared their virological differences. Interestingly, circulating CV-A16 viruses are more pathogenic in a neonatal mouse model than is CV-A16 G10. Thus, we have found circulating recombinant forms of CV-A16 (CRF CV-A16) that are related to, but different from, the prototype CV-A16 G10 that have distinct biological phenotypes.
    Full-text · Article · Apr 2014 · PLoS ONE
  • Source
    • "Especially since the late 1990s, a significant increase in EV71 epidemics is observed, creating a serious threat to public health throughout the Asia-Pacific region [5-7]. For example, in 2007, more than 80,000 HFMD cases were reported with dozens of deaths in mainland China [8,9]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: To clarify the molecular mechanisms that participate in the severe hand, foot and mouth disease (HFMD) infected by Enterovirus 71 and to detect any related protein biomarkers, we performed proteomic analysis of protein extracts from 5 extremely severe HFMD children and 5 healthy children. The protein profiles of them were compared using two-dimensional electrophoresis. Differentially expressed proteins were identified using mass spectrometry. Functional classifications of these proteins were based on the PANTHER. The interaction network of the differentially expressed protein was generated with Pathway Studio. A total of 38 differentially expressed proteins were identified. Functional classifications of these proteins indicated a series of altered cellular processes as a consequence of the severe HFMD. These results provided not only new insights into the pathogenesis of severe HFMD, but also implications of potential therapeutic designs. Our results suggested the possible pathways that could be the potential targets for novel therapy: viral protection, complement system and peroxide elimination.
    Full-text · Article · Aug 2013 · BMC Infectious Diseases
Show more