OBJECTIVETo provide a feasible and cost-effective next-generation sequencing (NGS) method for accurate identification of viral pathogens in clinical specimens, because enormous limitations impede the clinical use of common NGS, such as high cost, complicated procedures, tremendous data analysis, and high background noise in clinical samples.

METHODSViruses from cell culture materials or clinical specimens were identified following an improved NGS procedure: reduction of background noise by sample preprocessing, viral enrichment by barcoded oligonucleotide (random hexamer or non-ribosomal hexanucleotide) primer-based amplification, fragmentation-free library construction and sequencing of one-tube mixtures, as well as rapid data analysis using an in-house pipeline.

RESULTSNGS data demonstrated that both barcoded primer sets were useful to simultaneously capture multiple viral pathogens in cell culture materials or clinical specimens and verified that hexanucleotide primers captured as many viral sequences as hexamers did. Moreover, direct testing of clinical specimens using this improved hexanucleotide primer-based NGS approach provided further detailed genotypes of enteroviruses causing hand, foot, and mouth disease (HFMD) and identified other potential viruses or differentiated misdiagnosis events.

CONCLUSIONThe improved barcoded oligonucleotide primer-based NGS approach is simplified, time saving, cost effective, and appropriate for direct identification of viral pathogens in clinical practice.

Clinical Laboratory Techniques ; DNA Barcoding, Taxonomic ; DNA Primers ; Enterovirus ; classification ; genetics ; isolation & purification ; Herpesvirus 4, Human ; genetics ; isolation & purification ; Humans ; Influenza B virus ; genetics ; isolation & purification ; Real-Time Polymerase Chain Reaction ; Sequence Analysis, DNA ; methods ; Sequence Analysis, RNA ; methods

Enterovirus 71 frequently involves the central nervous system and may present with a variety of neurologic manifestations. Here, we aimed to describe the clinical features, magnetic resonance imaging (MRI) findings, and cerebrospinal fluid (CSF) profiles of patients presenting with neurologic complications of enterovirus 71 infection. We retrospectively reviewed the records of 31 pediatric patients hospitalized with acute neurologic manifestations accompanied by confirmed enterovirus 71 infection at Ulsan University Hospital between 2010 and 2014. The patients' mean age was 2.9 ± 5.5 years (range, 18 days to 12 years), and 80.6% of patients were less than 4 years old. Based on their clinical features, the patients were classified into 4 clinical groups: brainstem encephalitis (n = 21), meningitis (n = 7), encephalitis (n = 2), and acute flaccid paralysis (n = 1). The common neurologic symptoms included myoclonus (58.1%), lethargy (54.8%), irritability (54.8%), vomiting (48.4%), ataxia (38.7%), and tremor (35.5%). Twenty-five patients underwent an MRI scan; of these, 14 (56.0%) revealed the characteristic increased T2 signal intensity in the posterior region of the brainstem and bilateral cerebellar dentate nuclei. Twenty-six of 30 patients (86.7%) showed CSF pleocytosis. Thirty patients (96.8%) recovered completely without any neurologic deficits; one patient (3.2%) died due to pulmonary hemorrhage and shock. In the present study, brainstem encephalitis was the most common neurologic manifestation of enterovirus 71 infection. The characteristic clinical symptoms such as myoclonus, ataxia, and tremor in conjunction with CSF pleocytosis and brainstem lesions on MR images are pathognomonic for diagnosis of neurologic involvement by enterovirus 71 infection.
Acute Disease ; Brain/diagnostic imaging ; Central Nervous System Diseases/etiology/*pathology ; Child ; Child, Preschool ; Encephalitis/pathology ; Enterovirus A, Human/genetics/*isolation & purification ; Enterovirus Infections/drug therapy/*pathology/virology ; Feces/virology ; Female ; Humans ; Immunoglobulins/administration & dosage ; Infant ; Injections, Intravenous ; Leukocytes/cytology ; Leukocytosis/cerebrospinal fluid/pathology ; Magnetic Resonance Imaging ; Male ; RNA, Viral/genetics/metabolism ; Real-Time Polymerase Chain Reaction ; Republic of Korea ; Retrospective Studies ; Seasons

OBJECTIVETo investigate the etiology of severe hand-foot-mouth disease (HFMD) in children in Henan province.

METHODSA total of 244 HFMD cases admitted to a hospital in Zhengzhou from April to June of 2014 were recruited for research sampling, Real-time RT-PCR, virus isolation, VP1 sequencing and alignment methods were used to test the enterovirus-related etiology. SPSS 17.0 was used in performing statistical analysis.

RESULTSThere were 109 severe and 135 mild cases among all the 244 HFMD cases. The number of enterovirus positive stool samples was 229, with positive rate as 93.85%. EV71, Cox A16 and Cox A10 made up 83.84%, 5.68% and 8.30% of the enterovirus etiologicy, strains, respectively. EV71 infection caused 8 HFMD cases with heart-lung failure and 2 death, Cox A10 infection led to 1 HFMD case with heart-lung failure and death. There were statistically differences seen regarding the enterovirus infection rates between severe and the mild HFMD cases (χ(2)=5.312,P=0.021). Statistically significant difference was seen in the constituent ratio of EV71, Cox A16 and the others by Fisher' s exact test (P=0.048). There was statistically significant difference seen between the cardiorespiratory failure rate and the fatality rate by EV71 and Cox A10 infection (χ(2)=0.051,P=0.821; χ(2)=2.198,P=0.138). Cox A10 strains idenfied in Henan in 2014 belonged to genotype 6. The rates on homology of nucleotide and amino acid among the Cox A10 strains in Henan in 2014 were 94.3%-99.7% and 96.3%-100.0% respectively.

CONCLUSIONSEV71 still remained the most common pathogen that causing severe HFMD in children, with the increasing Cox A10 percentage in the pathogens spectrum of HFMD infection. Cox A10 strains in Henan in 2014 belonged to genotype 6. Genotype 6 Cox A10 had appeared and widely distributed in Henan for long time, but not yet variated or reconstructed. Cox A10 infection could lead to cardio-respiratory failure thus called for the monitoring program on non-EV71 and non-Cox A16 enterovirus, especially Cox A10 to be strenthened.

Amino Acids ; genetics ; Biometry ; Child ; Enterovirus A, Human ; classification ; genetics ; isolation & purification ; Enterovirus Infections ; epidemiology ; virology ; Evolution, Molecular ; Genotype ; Hand, Foot and Mouth Disease ; epidemiology ; prevention & control ; virology ; Hospitals ; statistics & numerical data ; Humans ; Real-Time Polymerase Chain Reaction

OBJECTIVETo study the molecular epidemiology of hand-foot-mounth disease (HFMD) associated Coxsackievirus A10 (Cox A10) identified in Fujian province.

METHODSA total of 1 525 specimens from non-EV71 non-Cox A16 HFMD patients were collected during 2011-2014. Isolated virus strains were identified and sub-typed. Full-length coding regions for the VP1 gene of the predominant serotype Cox A10 isolates were amplified and sequenced.

RESULTSAmong the 407 non-EV71 non-Cox A16 HFMD cases confirmed by virus isolation and molecular subtyping, 103 (25.3%) were caused by Cox A10, accounting for 11.0%, 6.0%, 18.4% and 9.2% among the HFMD-associated entero-viruses identified in 2011, 2012, 2013 and 2014, respectively, in Fujian province. Compared to the general features observed in the HFMD epidemics, no differences on the Cox A10-specificity rates were observed among factors as geographical origins, gender or age groups, but all with high rates of severity. Data from the nucleotide sequence analyses on VP1 genes showed low homology levels of 76.0%-77.1% among Cox A10 strains from Fujian province, in contrast to the prototype Cox A10 strain, but with high levels of homology in the amino acid sequences (91.9%-93.6%). RESULTS from the Phylogenetic analysis also indicated that Cox A10 isolates from Fujian province were distinct from the prototype strain or other isolates from other countries but was homologous to domestic strains, but the Fujian isolates clustered into multiple branches.

CONCLUSIONSCox A10 remained one of the predominant serotypes of HFMD in Fujian province. Cox A10 isolates identified in Fujian province were co-circulating and co-evolving with other domestic strains.

Benzeneacetamides ; Child ; Child, Preschool ; China ; epidemiology ; Enterovirus A, Human ; classification ; genetics ; isolation & purification ; Epidemics ; Female ; Hand, Foot and Mouth Disease ; epidemiology ; genetics ; virology ; Humans ; Infant ; Male ; Molecular Epidemiology ; Molecular Sequence Data ; Open Reading Frames ; Phylogeny ; Piperidones ; Serogroup

We analyzed the genetic characteristics of coxsackievirus A4 (CV-A4) based on the entire VP1 coding region. Samples were isolated from patients with acute flaccid paralysis (AFP) in Shaanxi, China from 2006 to 2010. We wished to ascertain the predominant genotype and the relationship between CV-A4 infection and AFP. Sixty-eight non-polio enteroviruses were inoculated onto RD cells (to increase the virus titer) and molecular typing was undertaken. The entire VP1 coding region was amplified. Percentage of CV-A4 was 10.3% (7/68). Analyses of genetic identify and creation of phylogenetic trees revealed that CV-A4 could be classified into A, B and C genotypes. Seven CV-A4 strains from Shaanxi and other CV-A4 strains from China formed an independent evolution lineage located in group 4 and belonged to the C2 sub-genotype. These data suggested that CV-A4 strains of sub-genotype C2 were the predominant genotypes in China. These strains co-evolved and co-circulated with those from other provinces in China, so continued monitoring of CV-A4 (by clinical and genetic surveillance) should be enhanced.
China ; Enterovirus A, Human ; classification ; genetics ; isolation & purification ; Enterovirus Infections ; virology ; Genotype ; Humans ; Paralysis ; virology ; Phylogeny ; Viral Proteins ; genetics

In the present study, the complete genomes of four common (4/EV71/Wenzhou/CHN/2014, 15/ EV71/Wenzhou/CHN/2014, 116/EV71/Wenzhou/ CHN/2014, and 120/EV71/Wenzhou/CHN/2014) and two virulent (11/EV71/Wenzhou/CHN/2014 and 109/EV71/Wenzhou/CHN/2014) enterovirus 71 (EV71) isolates were sequenced and described. They are 7405 bp in length and belong to EV71 sub-genotype C4 (C4a cluster). Nucleotide sequence alignment revealed six nucleotide variations (GP151→TP151, GP199→AP199, GP261→TP261, AP328→CP328, GP422→AP422, and GP437→TP437) in the two virulent isolates within the 5'UTR of the IRES element. RNA secondary structure predictions of IRES and FCE indicated that the common isolates shared similar structures, which were different from those of the virulent isolates. Moreover, the GP114→CP114 and GP151→TP151 mutations in the virulent isolates contributed to the formation of the unique RNA secondary structures in SL II. Furthermore, nucleotide/amino acid sequence alignments of 82 EV71 isolates indicated that six sites (TP488 and CP577 in the 5'UTR; AsnP57 in 2A; IleP56 in 3C; CP10 and AP47 in the 3'UTR) are potentially associated with the neurovirulence of EV71. Finally, the 3D structures of 2A were analogous, whereas the structures of VP1 and 3C were variable.
Base Sequence ; Central Nervous System ; virology ; Enterovirus A, Human ; classification ; genetics ; isolation & purification ; pathogenicity ; Enterovirus Infections ; virology ; Genome, Viral ; Genomics ; Genotype ; Humans ; Molecular Sequence Data ; Nucleic Acid Conformation ; Phylogeny ; RNA, Viral ; chemistry ; genetics ; Virulence

A retrospective surveillance study on enterovirus D68 was performed in Beijing, China, following the largest and most widespread EV-D68 infection, which occurred in the USA. From January 2011 to July 2015, EV-D68 was identified in 12 individuals with respiratory infections in Beijing, China. The phylogenetic relationships based on the genomic sequence alignment showed that there were two lineages circulating in Beijing from 2011 to 2015. Eight EV-D68 strains belonged to group 1 and four belonged to group 3. All EV-D68 strains from Beijing in 2014 were separately clustered into subgroup II of group 1. Based on these results, we concluded that the Beijing EV-D68 strains had little association with the EV-D68 strains circulating in the 2014 USA outbreak.
Adolescent ; Aged ; Beijing ; epidemiology ; Child ; Child, Preschool ; Enterovirus D, Human ; classification ; genetics ; isolation & purification ; Enterovirus Infections ; epidemiology ; virology ; Female ; Genome, Viral ; Humans ; Male ; Phylogeny ; Retrospective Studies

OBJECTIVETo study the genetic characteristics of VP1 region of coxsackievirus A10 (Cox A10) strains isolated from hand foot and mouth disease (HFMD) cases in Ningxia Hui Autonomous Region (Ningxia) in 2013.

METHODSA total of 280 specimens, which were identified as non-enterovirus 71 and non-Cox A16 by real-time PCR, were collected and cultured by using RD cell, and the VP1 genes of isolated strains were amplified by using reverse transcriptase PCR (RT-PCR) with degenerated primers and sequenced. The sequencing results were aligned with the sequences in GenBank with BLAST algorithm to identify the virus genotypes. Homologous comparison and phylogenetic analysis were conducted for all the Cox A10 strains identified.

RESULTSAmong 36 virus strains isolated from 280 clinical specimens, 6 were identified as Cox A10. The homologies of nucleotide and amino acid of the Cox A10 strains isolated in Ningxia were 97.0%-99.8% and 99.0%-99.7% respectively, and the Cox A10 strains isolated in Ningxia shared 76.3%-77.2%, 81.6%-83.1%, 94.4%-98.9% and 80.0%-82.3% nucleotide homologies respectively and shared 92.3%-93.0%, 94.0%-95.3%, 98.0%-99.7% and 90.6%-94.0% amino acid homologies respectively with the representative strains of A, B, C and D genotypes. Phylogenetic tree analysis revealed that Cox A10 strains isolated in Ningxia belonged to genotype C.

CONCLUSIONCox A10 is one of the most common pathogen causing HFMD in Ningxia in 2013. All the Cox A10 stains isolated from HFMD patients in Ningxia belonged to genotype C.

Algorithms ; Amino Acids ; China ; Databases, Nucleic Acid ; Enterovirus A, Human ; genetics ; isolation & purification ; Genotype ; Hand, Foot and Mouth Disease ; virology ; Humans ; Phylogeny ; Real-Time Polymerase Chain Reaction

To study on the phylogenetic characterization of the VP1 genes of coxsackievirus A16 (CVA16) causing hand-food-mouth disease (HFMD) isolated from Anhui province in 2014. A total of 413 throat swab specimens from HFMD patients were collected during January to November, 2014 for the isolation and identification of enteroviruses using real-time RT-PCR assays. The VP1 regions of CVA16 isolates were amplified using RT-PCR and sequenced. And the phylogenetic tree was constructed among the VP1 regions of those isolates, the different genotypes and sub-genotypes of CVA16 strains. A total of 97 enteroviruses were isolated from 413 samples, the positive rate was 23.49% (97/413), including seventeen CVA16, seventy six HEV71 and four other enteroviruses. The results of the phylogenetic tree showed that 17.CVA16 strains isolated from Anhui in 2014 clustered within B1b evolution branch of B1 genotype. The nucleotide and amino acid sequence identities were 95.30%-100% and 98.70%-100% among the isolates, respectively, but within B1b branch of 17 strains formed several small transmission chains. The nucleotide acid of 17 CVA16 isolates in Anhui province were closed to the strains isolated from Yunnan, Hunan, Guangdong, Tibet and Jiangsu, especially from Hunan in 2013 and from Shenzhen of Guangdong in 2014, the identity were 96.40%-99.70%. The CVA16 strains isolated from Anhui in 2014 were all belong to genetic subtype B1b of B1 genotype was dominant, and among those isolates, several small virus transmission chains had formed with co-circulating and evolution.
China ; Enterovirus A, Human ; classification ; genetics ; isolation & purification ; Enterovirus Infections ; virology ; Genotype ; Humans ; Molecular Sequence Data ; Phylogeny ; Viral Proteins ; genetics ; metabolism

To identify the cause of an outbreak of acute hemorrhagic conjunctivitis (AHC) in Jiangxi (China) in 2010, 20 eye conjunctival swabs were first collected from AHC patients. Then, viruses were isola- ted and tested for human enterovirus 70, coxsackievirus A24 variant (CV-A24v) and adenovirus using the polymerase chain reaction. All CV-A24v isolates underwent sequencing of 3C and VP1 coding regions. Then, a phylogenetic tree was constructed for Jiangxi CV-A24v and worldwide CV-A24v based on,3C and VP1 regions, respectively. Ten out of 20 specimens were positive for CV-A24v, implying that the outbreak was caused by CV-A24v. The phylogenetic tree based on the 3C region showed that Jiangxi CV- A24v belonged to cluster 5 in genotype IV (GIV-C5) with strains isolated throughout the world after 2010, and were divided further into A and B lineages. Phylogenetic analyses of the VP1 region showed that all of the worldwide CV-A24v strains isolated after 2000 could be divided into five groups (1-5). Jiangxi CV-A24v was classified into group 5 and also divided further into A and B lineages upon analyses of the 3C region. These data suggested that CV-A24v causing AHC outbreaks in China in 2010 belonged to GIV-C3 and GIV-C5. At least two transmission lineages were circulated in Jiangxi in 2010. The classification of CV-A24v isolated after 2010 worldwide using the phylogenetic tree based on the VP1 region was almost consistent with that based on the 3C region and also had significant chronological clustering.
China ; epidemiology ; Conjunctivitis, Acute Hemorrhagic ; epidemiology ; virology ; Coxsackievirus Infections ; epidemiology ; virology ; Disease Outbreaks ; Enterovirus C, Human ; classification ; genetics ; isolation & purification ; Genotype ; Humans ; Molecular Sequence Data ; Phylogeny ; Viral Proteins ; genetics