Molecular and epidemiological study of human adenovirus among infants with diarrhea in Nanjing / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the prevalence, clinic features and epidemiologic characteristics of human adenovirus diarrhea in Nanjing.</p><p><b>METHODS</b>730 stool specimens were collected from children with diarrhea in Nanjing Children's Hospital of Nanjing Medical University from June 2009 to June 2011. Polymerase chain reaction (PCR) was employed to detect human adenovirus. The total positive PCR products were typed by nest-PCR or multiple PCR.</p><p><b>RESULTS</b>21 samples (21/730) were positive for human adenovirus of all 730 samples from June 2009 to June 2011 and enteric HAdV-41 is the predominant stain.</p><p><b>CONCLUSION</b>Enteric HAdV-41 and non-enteric adenovirus were the major etiological agents of viral diarrhea among infants and children in Nanjing from 2009 to 2011. We should take the long-term systematic surveillance seriously.</p>

Etiology of hand-foot-and-mouth disease seen in Nanjing in 2010 and molecular characteristics analysis of EV71 / 中华儿科杂志

<p><b>OBJECTIVE</b>To study the etiological agent of hand-foot-and-mouth disease (HFMD), and to genetically characterize enterovirus 71 (EV71) isolated from clinical specimens of HFMD patients in Nanjing in 2010.</p><p><b>METHOD</b>Throat swab specimens were collected from 248 inpatients with HFMD in Nanjing Children's Hospital and then viral isolation was performed. Real-time PCR was used for detection of EV71, coxsackievirus A16 (Cox A16) and other enteroviruses from the positive isolates. Twenty EV71 strains from different clinical types of cases were selected for entire VP1 coding gene amplification and sequencing, finally a phylogenetic tree was constructed among the 20 EV71 strains and EV71 representative strains of known genotypes and subgenotypes.</p><p><b>RESULT</b>From the 248 throat swabs specimens, 110 EV71 strains, 28 Cox A16 strains, and 8 other enterovirus strains were isolated and the positive rate was 44.35%, 11.29%, 3.23%, respectively. Then nucleotide sequencing was performed on the 20 EV71 strains. There was little difference in the nucleotide and the amino acid sequences among the 20 EV71 strains, the homology was 95.51%-100% and 98.32%-100%, respectively. The phylogenetic tree showed that all the 20 EV71 strains belonged to C4 subgenotype.</p><p><b>CONCLUSION</b>EV71 was the main pathogen of HFMD in Nanjing in 2010 and all the analyzed isolates belonged to C4 serotype. No significant difference was found in sequence of VP1 region of EV71 isolated from different clinical types of cases.</p>

Molecular and epidemiological study on among children under 5 years old in Nanjing / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the infected information, clinical symptom and molecular epidemiological characteristics of HuCV infection among children under 5 years old in Nanjing.</p><p><b>METHODS</b>In Nanjing Children's Hospital of Nanjing Medical University from July 2010 to June 2011, we collected 428 stool specimens from children with diarrhea and 428 asymptomatic controls. Human Calicivirus were tested by using RT-PCR. Then we sequenced the nucleic acid of PCR amplifications and identified the genotype and gene group of prevalent strains.</p><p><b>RESULTS</b>63 (14.72%) out of 428 stool samples were detected as HuCV. 58 were norovirus and 5 were sapovirus, while GII-4 2006b was the predominant strain of NoV. In the 428 control samples, 19 samples were positive for calicivirus, there were 8 NoV and 13 SaV (Including 3 co-infection cases).</p><p><b>CONCLUSION</b>Human caliciviruses with different genotypes circulated among children in Nanjing,and GII. 2006b is the dominant genotype.</p>

Optimizing expression of the capsid protein VP2 from human Bocavirus and establish it's seroepidemiology assying methord / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To obtain sufficient recombinant VP2 protein of human Bocavirus and establish it's seroepidemiology assying metbord. METHORD: Tbe capsid protein VP2 DNA genes of HBoV1 and 2 were optimized in accordance with tbe usage of the favorite codons in K coil so as to enhance its protein expression in prokaryotic expressing system. The protein was purified by Ni-NTA column, and its antigenicity was determined by Western Blot. Then establish ELISA to detect the specific anti-VP2 IgG antibodies against HBoV1 and 2 in healthy children aged 3-6 years in Nanjing, China.</p><p><b>RESULTS</b>The recombinant protein 6 x His-VP2 was produced in a larger quantity at 25 degrees C induced by IPTG (1 mmol/L) over night and purified by Ni-NTA column. Seropositive rates of HBoV1 and 2 were 62.2% and 55.5% and their mixed seropositivity was 37%.</p><p><b>CONCLUSION</b>The optimizing expression of the capsid protein VP2 from human Bocavirus constructed successfully and get a high yield under certain conditions. The established ELISA could be used to further analyze seroepidemiology of HBoV in China.</p>