From phyllosphere to insect cuticles: silkworms gather antifungal bacteria from mulberry leaves to battle fungal parasite attacks.

BACKGROUND: Bacterial transfers from plants to insect herbivore guts have been well investigated. However, bacterial exchanges between plant phyllospheres and insect cuticles remain unclear, as does their related biological function. RESULTS: Here, we report that the cuticular bacterial loads of silkworm larvae quickly increased after molting and feeding on the white mulberry (Morus alba) leaves. The isolation and examination of silkworm cuticular bacteria identified one bacterium Mammaliicoccus sciuri that could completely inhibit the spore germination of fungal entomopathogens Metarhizium robertsii and Beauveria bassiana. Interestingly, Ma. sciuri was evident originally from mulberry leaves, which could produce a secreted chitinolytic lysozyme (termed Msp1) to damage fungal cell walls. In consistency, the deletion of Msp1 substantially impaired bacterial antifungal activity. Pretreating silkworm larvae with Ma. sciuri cells followed by fungal topical infections revealed that this bacterium could help defend silkworms against fungal infections. Unsurprisingly, the protective efficacy of ΔMsp1 was considerably reduced when compared with that of wild-type bacterium. Administration of bacterium-treated diets had no negative effect on silkworm development; instead, bacterial supplementation could protect the artificial diet from Aspergillus contamination. CONCLUSIONS: The results of this study evidence that the cross-kingdom transfer of bacteria from plant phyllospheres to insect herbivore cuticles can help protect insects against fungal parasite attacks. Video Abstract.

Immunogenicity and protective efficacy of human metapneumovirus virus-like particles produced by a recombinant baculovirus in mice.

BACKGROUND: Human metapneumovirus (HMPV) causes respiratory tract infections among infant, elderly, and immunocompromised patients, with significant mortality. Currently no licensed vaccines or therapeutic agents of HMPV exist. METHODS: HMPV virus-like particle (VLP) was constructed by co-expressing fusion protein of HMPV and matrix 1 protein of influenza virus using the baculovirus expression. Mice were immunized with VLP with or without aluminum hydroxide (alum) adjuvant by intramuscular route respectively. Sera were determined for titers of IgG and neutralizing antibody. Splenic lymphocytes were determined by IFN-γ and IL-4 ELISPOT. Mice were challenged with HMPV, and protective efficacy was evaluated. RESULTS: We generated HMPV VLP in baculovirus expression system. After three times immunization, IgG antibody titers induced by VLP formulated with or without alum adjuvant group were 273,066 ± 100,331 and 136,533 ± 47,269 respectively, there was no difference (p Ëƒ 0.05); the neutralizing antibody titers vaccinated with VLP plus with alum adjuvant (266 ± 92) were higher than those of the VLP alone group (106 ± 37). For IFN-γ, mice vaccinated with VLP with or without alum adjuvant are 151 ± 36.4 and 77.0 ± 17.1SFC/106 respectively, there was difference (p = 0.03); For IL-4, they are 261.3 ± 38.7 versus 125.67 ± 29.78SFC/106 respectively, the difference was significant (p = 0.009). After challenge, in pathological analysis, the overall lesion scores in the VLP plus with and without alum adjuvant were 3.25 and 5.6 respectively, those of control group is 8. For immunohistochemical analyses, the average optical density of the lungs in the VLP immunized group containing adjuvant (9.07 ± 1.74) was lower than that in the VLP group without adjuvant (12.83 ± 2.31, p = 0.14). CONCLUSIONS: This is the first study to demonstrate that HMPV VLP was successfully prepared in the baculovirus expression system. HMPV VLP could induce specific humoral and cellular immune responses as well as protective efficacy, and aluminum hydroxide may be an effective adjuvant in mice.

Development and biological activity of long-acting recombinant human interferon-α2b.

BACKGROUND: The type I human interferon (IFN) family consists of a group of cytokines with a multiplicity of biological activities, including antiviral, antitumor, and immunomodulatory effects. However, because the half-life of IFN is short, its clinical application is limited. Increasing the yield and biological activity of IFN while extending its half-life is currently the focus of IFN research. RESULTS: Two novel long-acting recombinant human IFN-α2b (rhIFN-α2b) proteins were designed in which the carboxyl-terminal peptide (CTP) of the human chorionic gonadotropin ß su bunit and N-linked glycosylation sequences were linked to rhIFN-α2b. They were designated IFN-1CTPON (fused at the C-terminus of rhIFN-α2b) and IFN-2CTPON (fused at both the C-terminus and N-terminus of rhIFN-α2b). Monoclonal CHO cell strains stably and efficiently expressing the IFNs were successfully selected with methotrexate (MTX), and the highest expression levels were 1468 mg/l and 1196 mg/l for IFN-1CTPON and IFN-2CTPON, respectively. The proteins were purified with affinity chromatography and molecular sieve chromatography. IFN-1CTPON and IFN-2CTPON showed antiviral and antiproliferative activities in vitro. Notably, the half-life of IFN-1CTPON and IFN-2CTPON in vivo were three-fold and two-fold longer than that of commercially available rhIFN-α2b. CONCLUSIONS: CHO cell strains stably expressing long-acting rhIFN-α2b were screened. The purified IFN-CTPON protein has biological activity and an extended half-life, and therefore potential applications.

Gradual replacement of all previously circulating respiratory syncytial virus A strain with the novel ON1 genotype in Lanzhou from 2010 to 2017.

ON1 is a novel genotype of human respiratory syncytial virus (HRSV) subtype A, in children with acute respiratory tract infections (ARTIs). However, there is not much data on the prevalence and clinical and molecular characterization in China.Our study is based on the children who had respiratory infections positive for RSV-A admitted by Gansu Provincial Maternity and Child-care Hospital in Lanzhou (northwestern China) during the last 7 epidemic seasons from 2010 to 2017.In our study, different strains of the novel RSV-A genotype ON1, first identified in Canada in December 2010, were first detected in Gansu Provincial Maternity and Child-care Hospital in August 2012 and then followed by an abrupt expansion in the number of ON1 variants in the beginning of 2014 and eventually replaced all other RSV-A strains from 2015 to 2017. ON1 is characterized by a 72-nt duplication in the C-terminal region of the highly variable attachment glycoprotein (G), predicted to lengthen the polypeptide with 24 amino acids, including a 23-aa duplication, which likely changes antigenicity. New N-glycosylation sites occurred within the 23-aa duplication and 24-aa insertion of the ON1 viruses in our study. Notably, RSV infections occurred later, but peaked sooner from the 2014/2015 to 2016/2017 epidemic seasons, compared with the previous 4 seasons.Our study concluded that genotype ON1 has caused larger outbreaks and became the predominate genotype for HRSV subgroup A in Lanzhou from 2013 to 2017, and became the sole genotype of RSV-A in 2015/2016 and 2016/2017. Our data indicate that northwest of China and the world will eventually be dominated by the ON1 RSV-A genotype, including the possibility for vaccine development. Based on trends seen in RSV-B BA genotype, which predominated for decades, there is a possibility to develop a vaccine for children in the next 10 years.

Epidemiology of human adenovirus infection in children hospitalized with lower respiratory tract infections in Hunan, China.

To investigate the current genotypes of circulating human adenovirus (HAdV) strains, we molecularly genotyped HAdV in the nasopharyngeal aspirates (NPAs) of patients with acute lower respiratory tract infections (ALRTIs) and attempted to determine their associations with clinical symptoms. A total of 4751 NPA samples were collected from 4751 patients admitted to Hunan Provincial People's Hospital from September 2007 to March 2014, of which 447 (9.4%) samples were HAdV positive. Fourteen different HAdV types were identified; HAdV types 1 to 7 (HAdV 1-7) were identified in 95.7% of the 447 NPA samples with HAdV-7 and HAdV-3 being the most prevalent. In addition, 93.3% (417 of 447) of patients were younger than 5 years. The incidence of HAdV infection peaked in summer. Different HAdV types showed a predilection for different age groups and different seasonal distribution patterns. Coinfection of HAdVs and other respiratory viruses was detected in 63.3% (283 of 447) of the HAdV-positive samples. The most common clinical diagnosis was pneumonia and the most common symptoms were fever and cough. In comparison with children infected with HAdV-3 alone, those infected with HAdV-7 alone had an increased frequency of severe pneumonia involvement (11.6% vs 32.4%; P = 0.031), higher intensive care unit admission rates (7.0% vs 26.5%; P = 0.019), and a longer length of hospital stay (P = 0.03). Mixed infections in younger children were associated with a longer hospital stay (P = 0.023). Our results demonstrate the recent changes in the trends of circulating HAdV genotypes associated with ALRTIs in Hunan China.

Human adenovirus load in respiratory tract secretions are predictors for disease severity in children with human adenovirus pneumonia.

BACKGROUND: Pneumonia is a serious public health issue and is concerned around the world. This study is to investigate the association between viral load in children with human adenovirus (HAdV) pneumonia and disease severity. METHODS: A total of 1313 cases of children hospitalized in Hunan Provincial People's Hospital due to community acquired pneumonia (CAP) from April 2011 to May 2014 were enrolled in this study. Samples of nasopharyngeal aspirate were collected for the cohort. WHO criteria for CAP grading was emerged for pneumonia severity classification. Real-time fluorescence quantitative PCR (qRT-PCR) was used to detect 12 kinds of respiratory viruses. HAdV types were identified by nested PCR. The relationship between HAdV load and severity of disease was there by analyzed. RESULTS: Finally, 174 cases (174/1313, 13.3%) were positive for HAdV, and HAdV type 7 (HAdV-7) was the main serotype (76/174, 43.7%). Among the 174 cases, 70 cases were with HAdV infection alone and 104 cases were accompanied by other viruses. The patients were divided into mild pneumonia group (n = 108 cases) and severe pneumonia group (n = 66 cases). HAdV load of children in severe pneumonia group was higher than that in mild pneumonia group. Similar result was obtained in the 70 cases with HAdV infection alone after subgrouping. Relevant factors analysis results showed that severe pneumonia children presented lower onset age, more prone to fever, longer fever time, and longer hospital stay compared with that of mild pneumonia children. Children with HAdV-7 infection developed more frequently severe pneumonia. Multivariate regression analysis showed that HAdV load, age, and fever time were risk factors for pneumonia severity. CONCLUSION: The severity of HAdV infection is significantly correlated with viral load and serotype.

Faecal shedding of rotavirus vaccine in Chinese children after vaccination with Lanzhou lamb rotavirus vaccine.

Lanzhou lamb rotavirus vaccine (LLR) is an oral live attenuated vaccine first licensed in China in 2000. To date, > 60 million doses of LLR have been distributed to children. However, very little is known about faecal shedding of LLR in children. Therefore, faecal samples (n = 1,184) were collected from 114 children for 15 days post-vaccination in September-November 2011/2012. Faecal shedding and viral loads were determined by an enzyme immunoassay kit (EIA) and real-time RT-PCR. The complete genome was sequenced and the vaccine strain was isolated by culture in MA104 cells. Approximately 14.0% (16/114) of children had rotavirus-positive samples by EIA for at least 1 day post-vaccination. Viral loads in EIA-positive samples ranged from < 1.0 × 103 to 1.9 × 108 copies/g. Faecal shedding occurred as early as post-vaccination day 2 and as late as post-vaccination day 13 and peaked on post-vaccination day 5-10. One LLR strain was isolated by culture in MA104 cells. Sequence analysis showed 99% identity with LLR prototype strain. Faecal shedding of LLR in stool is common within 15 days of LLR vaccination, indicating vaccine strains can replicate in human enteric tissues.

Human bocavirus and human metapneumovirus in hospitalized children with lower respiratory tract illness in Changsha, China.

BACKGROUND: Lower respiratory tract illness is a major cause of morbidity and mortality in children worldwide, however, information about the epidemiological and clinical characteristics of LRTIs caused by HMPV and HBoV in China is limited. OBJECTIVES: Human bocavirus (HBoV) and human metapneumovirus (HMPV) are two important viruses for children with lower respiratory tract infections (LRTI). We aimed to assay the correlation between viral load and clinical characteristics of HBoV and HMPV with LRTI in Changsha, China. METHODS: Nasopharyngeal aspirates (NPAs) from children with LRTI were collected. Real-time PCR was used to screen HBoV and HMPV. Analyses were performed using SPSS 16.0 software. RESULTS: Pneumonia was the most frequent diagnosis. There was no significant difference between HBoV- and HMPV-positive patients in age (P = .506) or hospitalization duration (P = .280); 24.1% and 18.2% were positive for HBoV and HMPV. HBoV infections peaked in summer (32.2%), and HMPV infections peaked in winter (28.9%). The HBoV-positive patients had a shorter hospitalization duration than the HBoV-negative patients (P = .021), and the HMPV-positive patients had a higher prevalence of fever than the HMPV-negative patients (P = .002). The HBoV viral load was significantly higher among patients aged <1 year (P = .006). The mean HBoV and HMPV viral loads were not significantly different between patients with single infections and coinfections. Patients infected with HBoV only were older than those coinfected with HBoV and other respiratory viruses (P = .005). No significant difference was found in the clinical characteristics of patients infected with HMPV only and those coinfected with HMPV and other respiratory viruses. CONCLUSION: Pneumonia was the most frequent diagnosis caused by HBoV and HMPV. Neither HBoV nor HMPV viral load was correlated with disease severity.

Clinical characteristics and viral load of respiratory syncytial virus and human metapneumovirus in children hospitaled for acute lower respiratory tract infection.

Respiratory syncytial virus (RSV) and human metapneumovirus (HMPV) are two common viral pathogens in acute lower respiratory tract infections (ALRTI). However, the association of viral load with clinical characteristics is not well-defined in ALRTI. To explore the correlation between viral load and clinical characteristics of RSV and HMPV in children hospitalized for ALRTI in Lanzhou, China. Three hundred and eighty-seven children hospitalized for ALRTI were enrolled. Nasopharyngeal aspirates (NPAs) were sampled from each children. Real-time PCR was used to screen RSV, HMPV, and twelve additional respiratory viruses. Bronchiolitis was the leading diagnoses both in RSV and HMPV positive patients. A significantly greater frequency of wheezing (52% vs. 33.52%, P = 0.000) was noted in RSV positive and negative patients. The RSV viral load was significant higher in children aged <1 year (P = 0.003), children without fever and wheezing (P = 0.015 and P = 0.000), days of illness <14 days (P = 0.002), children with bronchiolitis (P = 0.012) and children with RSV single infections (P = 0.000). No difference was found in the clinical features of HMPV positive and negative patients. The HMPV viral load had no correlation with any clinical characteristics. The incidences of severe disease were similar between single infection and coinfection for the two viruses (RSV, P = 0.221; HMPV, P = 0.764) and there has no statistical significance between severity and viral load (P = 0.166 and P = 0.721). Bronchiolitis is the most common disease caused by RSV and HMPV. High viral load or co-infection may be associated with some symptoms but neither has a significant impact on disease severity for the two viruses. J. Med. Virol. 89:589-597, 2017. © 2016 Wiley Periodicals, Inc.

Identification of 12 Cases of Acute Measles Encephalitis Without Rash.

Twelve cases of acute measles encephalitis without rash were identified from October 2011 to July 2013 in Changsha city, China; 5 were found to be genotype H1 and 2 were B3. Our data suggest that screening for measles virus is necessary in children with viral encephalitis, to eliminate the disease.

Human parainfluenza virus types 1-4 in hospitalized children with acute lower respiratory infections in China.

Human parainfluenza viruses (HPIVs) are an important cause of acute lower respiratory tract infections (ALRTIs). HPIV-4, a newly identified virus, has been associated with severe ALRTIs recently. A total of 771 nasopharyngeal aspirate samples were collected from hospitalized children between March 2010 and February 2011. HPIVs were detected by Nest-PCR, and other known respiratory viruses were detected by RT-PCR and PCR. All amplification products were sequenced. HPIVs were detected in 151 (19.58%) patients, of whom 28 (3.63%) were positive for HPIV-4, 12(1.55%) for HPIV-1, 4 (0.51%) for HPIV-2, and 107 (13.87%) for HPIV-3. Only three were found to be co-infected with different types of HPIVs. All HPIV-positive children were under 5 years of age, with the majority being less than 1 year. Only the detection rate of HPIV-3 had a significant statistical difference (χ2 = 29.648, P = 0.000) between ages. HPIV-3 and HPIV-4 were detected during the summer. Sixty (39.74%) were co-infected with other respiratory viruses, and human rhinovirus (HRV) was the most common co-infecting virus. The most frequent clinical diagnosis was bronchopneumonia, and all patients had cough; some patients who were infected with HPIV-3 and HPIV-4 had polypnea and cyanosis. No significant difference was found in clinical manifestations between those who were infected with HPIV-4 and HPIV-3. Two genotypes for HPIV-4 were prevalent, although HPIV-4a dominated. HPIV-4 is an important virus for children hospitalized with ALRTIs in China. HRV was the most common co-infecting virus. Two genotypes for HPIV-4 are prevalent, HPIV-4a dominated. J. Med. Virol. 88:2085-2091, 2016. © 2016 Wiley Periodicals, Inc.

A novel hepatovirus identified in wild woodchuck Marmota himalayana.

Hepatitis A virus (HAV) is a hepatotropic picornavirus that causes acute liver disease worldwide. Here, we report on the identification of a novel hepatovirus tentatively named Marmota Himalayana hepatovirus (MHHAV) in wild woodchucks (Marmota Himalayana) in China. The genomic and molecular characterization of MHHAV indicated that it is most closely related genetically to HAV. MHHAV has wide tissue distribution but shows tropism for the liver. The virus is morphologically and structurally similar to HAV. The pattern of its codon usage bias is also consistent with that of HAV. Phylogenetic analysis indicated that MHHAV groups with known HAVs but forms an independent branch, and represents a new species in the genus Hepatovirus within the family Picornaviridae. Antigenic site analysis suggested MHHAV has a new antigenic property to other HAVs. Further evolutionary analysis of MHHAV and primate HAVs led to a most recent common ancestor estimate of 1,000 years ago, while the common ancestor of all HAV-related viruses including phopivirus can be traced back to 1800 years ago. The discovery of MHHAV may provide new insights into the origin and evolution of HAV and a model system with which to explore the pathogenesis of HAV infection.

Outbreak of febrile illness caused by coxsackievirus A4 in a nursery school in Beijing, China.

BACKGROUND: Coxsackievirus A4 (CV-A4) is classified as human enterovirus A according to its serotype. CV-A4, an etiological agent of hand, foot, and mouth disease, affects children worldwide and can circulate in closed environments such as schools and hospitals for long periods. FINDINGS: An outbreak of febrile illness at a nursery school in Beijing, China, was confirmed to be caused by CV-A4. Phylogenetic analysis of the complete genome of the isolated strain showed that the virus belongs to the same cluster as the predominant CV-A4 strain in China. This outbreak was controlled by effective measures. CONCLUSIONS: The early identification of the pathogen and timely intervention may be the most critical factors in controlling an outbreak caused by CV-A4 in a preschool.

Immunogenicity of recombinant human bocavirus-1,2 VP2 gene virus-like particles in mice.

Human bocavirus (HBoV), a recently identified pathogen with a worldwide distribution is closely related to paediatric acute respiratory infection and gastroenteritis. The present study was performed to evaluate the immunogenicity of HBoV1 and HBoV2 virus-like particles (VLPs) as vaccine candidates in mice. Both HBoV1 and HBoV2 VLPs were expressed in the bacmid virus­SF9 cell system. Mice were inoculated three times at 3-week intervals with HBoV VLPs at one dose intramuscular (i.m.) or intradermal (i.d.) with or without the addition of the alum adjuvant. ELISA was used to detected antibody, and ELISPOT was used to test cellular immune responses. HBoV-specific IgG antibodies were induced and alum adjuvant improved the antibody titres and avidity, while the inoculation pathway had no influence. T helper type 1/ type 2 immune responses were balanced induced by HBoV1 VLPs but not HBoV2 VLPs. Serum IgG antibody cross-reactivity rates of the two subtypes were similar, but cross-reactions of HBoV1 immunization groups were higher. The single i.m. group had more interferon-γ-secreting splenocytes. These data indicate that HBoV VP2 VLPs have good immunogenicity with induction of strong humoral and cellular immune responses, and they may be potential candidate vaccines for HBoV infection.

[Virus detection in bronchoalveolar lavage fluid of 122 children with severe pneumonia].

OBJECTIVE: To investigate the prevalence of viral pathogen in children with severe pneumonia in Hunan. METHOD: Bronchoalveolar lavage fluid [BALF] were collected from 122 hospitalized children with severe pneumonia in People's Hospital of Hunan province from January 2011 to December 2011. Nested- or reverse transcription Polymerase chain reaction (PCR or RT-PCR) was used to screen Adenovirus (ADV), Human Bocavirus (HBoV), Parainfluenzaviruses1-4 (PIV1-4), Human Respiratory Syneytial virus (RSV), Influenza virus A (IFVA), Influenza virus B (IFVB), Human Rhinovirus(HRV), Human Metapneumovirus (HMPV), human coronaviruses NL63 and HKU1 (HCoV-NL63, HCoV- HKU1). RESULTS: Among the 122 bronchoalveolar lavage fluid, viral agents were detected in 60 samples(49.1%), among which ADV (40.98%) was the most common virus, followed by RSV (7.37%) and HBoV (7.37%). Two viruses were detected in 21 individual (35%) samples, of which 20 were dual positive for ADV (40%). CONCLUSION: ADV is the most frequently detected viral etiology of severe pneumonia in children in Hunan during this year. And its Coinfection with other respiratory viruses was common.

[Establishment and clinical application of TapMan real-time RT-PCR method for detection of HHV-6].

OBJECTIVE: To establish a rapid, sensitive and specific real-time PCR method for detection of Human Herpesvirus-6 (HHV-6). METHODS: According to the reference, a pair of primers and a probe were designed located in U65-66 gene and to set up the standards. We established a real-time RT-PCR method for detection of HHV-6, and to verify the specificity, sensitivity, reproducibility. RESULTS: The correlation coefficient was 0.999, E = 97.9%, the coefficient of variation values of Ct were 0.61% and 3.13% in real-time PCR assay for inter and intra assay, respectively. The results of all viruses were negative except of HHV-6 for the assay. The quantitative detection limit of the assay was 3 x 10(0) copies/microl. CONCLUSION: The real-time PCR assay is highly specific, sensitive and reproducible, which can be used to quatitative detecting clinical samples.

Prevalence of adenovirus in children with acute respiratory tract infection in Lanzhou, China.

BACKGROUND: Human adenovirus (HAdV) is an important agent causing respiratory tract infection in children. Information on the epidemiological and clinical features of HAdV is limited in children with acute respiratory tract infections (ARTIs) in China, especially those of a novel genotype, Ad55. METHODS: In total, 1169 nasopharyngeal aspirates were collected from children younger than 14 years with ARTIs between November 2006 and November 2009. The polymerase chain reaction (PCR) was used to screen HAdVs. All PCR-positive products were sequenced. RESULTS: 74 of 1169 (6.33%) specimens were positive for HAdVs. Among positive cases, AdV3 (58/74) was detected most frequently, followed by AdV11 (10/74), AdV2 (2/74), AdV7 (2/69), AdV6 (1/74), and AdV1 (1/74). AdV55 was found in one case. The incidence of HAdV infection peaked in children aged 3-7 years. The most common clinical diagnosis was upper respiratory infection, and the most common syndrome was fever and cough.The comparison of HAdV and RSV group revealed that Children infected with group AdV were significant older than children infected with group RSV, had more fever but less frequently wheezing, and cough, crackles, and cyanosis, The duration of hospitalization between the AdV group and RSV group was not significant, but a greater frequency of LRTIs was observed in RSV group. CONCLUSIONS: HAdV is an important viral agent in children with ARTIs in Lanzhou City, China. Multiple HAdV serotypes co-circulated with Ad3, which was predominant in this 3-year study. The novel AdV55 genotype was found in one case. No fixed seasonal rhythm could be identified.

Prevalence of human metapneumovirus in children with acute lower respiratory infection in Changsha, China.

Human metapneumovirus (hMPV) causes acute respiratory infections in children. The prevalence and clinical characteristics of hMPV were determined in nasopharyngeal aspirates of children in Changsha, China. Reverse transcription-polymerase chain reaction (RT-PCR) or PCR was employed to screen for both hMPV and other common respiratory viruses in 1,165 nasopharyngeal aspirate specimens collected from children with lower respiratory tract infections from September 2007 to August 2008. All PCR products were sequenced, and demographic and clinical data were collected from all patients. Seventy-six of 1,165 (6.5%) specimens were positive for hMPV, of which 85.5% (65/76) occurred in the winter and spring seasons. The hMPV coinfection rate was 57.9% (44/76), and human bocavirus was the most common virus detected in conjunction with hMPV. Phylogenetic analysis revealed that 94.7% of the hMPV detected were of subgroup A2, 5.3% were subgroup B2, and none belonged to either the A1 or B1 subgroups. No significant differences were found in terms of the frequency of diagnosis and clinical signs between either the co- and mono-infection groups, or between patients with and without underlying diseases. It was concluded that hMPV is an important viral pathogen in pediatric patients with lower respiratory tract infections in Changsha. Only hMPV genotypes A2 and B2 were co-circulating in this locality; human bocavirus was the most common coinfecting virus, and coinfection did not affect disease severity.

[The epidemiological study of adenovirus in children with respiratory tract infections in Nanjing area from 2010 to 2011].

UNLABELLED: To investigate the epidemiological features and types of human adenoviruses (ADV) in children with acute respiratory tract infection in Nanjing area, China. Nasopharyngeal aspirates and nasopharyngeal swabs were collected from 644 outpatients or hospitalized pediatric patients with ARTI at the Children Hospital of Nanjing, Jiangsu Province, China, between August 2010 and July 2011. Adenoviruses were identified and typed from the collected clinical specimens by nested-PCR based on the partial region of the hexon gene. Other 12 respiratory viruses including human bocavirus (HBoV), respiratory syncytial virus (RSV), human rhinovirus (HRV), parainfluenza viruses 1-4 (PIV1-4), influenza virus A/B (IFVA/B), human metapneumovirus (HMPV), human coronavirus NL63 and HKU1 (HCoV-HKU1 and HCoV-NL63) were also identified by PCR method. All PCR positive products were sequenced and phylogenetic analysis was conducted. It was showed that adenoviruses were detected in 171 patients out of 644 (26. 55%) children, 120 (70.18%, 120/171) for ADV3, 16 (9.36%,16/171) for ADV7, 12 (7.02%, 12/171) for ADV1, 10 (5.85%, 10/171) for ADV2, 6 (3.51%, 6/171) for ADV5, 3 (1.75%, 3/171) for ADV6, 3 (1.75%, 3/171) for ADV57, and 1 (0.58%,1/171) for ADV41. ADV infection could occur in any season. There was a higher possibility of ADV infection from April to July in 2011. Most cases (96.49%) were younger than 7 years old. A total of 99 of the 171 ADV-positive children (57.89%) were co-infected with other respiratory viruses. Respiratory syncytial virus (RSV) and human rhinovirus (HRV) were the most common additional respiratory viruses, Lower respiratory tract infections were the most frequent diagnoses made in the hospital, in which there were 52 pneumonia (30.4%) cases. CONCLUSION: ADV is one of the most important pathogens of acute respiratory tract infection in children in Nanjing area, and adenovirus type 3 was the most prevalent serotype. It is important to develop long-term surveillance.

[Molecular epidemiological and clinical feature of human metapneumovirus in children with acute lower respiratory tract infection in Changsha area from 2007 to 2011].

OBJECTIVE: To understand the epidemiological characteristics of human metapneumovirus (hMPV) infection in children with acute lower respiratory tract infection (ALRTI) in Changsha area, China. METHODS: A total of 2613 nasopharyngeal aspirate (NPA) specimens were collected from hospitalized children with ARTIs between September 2007 and February 2011 (a period of 3.5 years) in Changsha area, Hunan Province, China. Respiratory specimens were screened for hMPV M gene by reverse-transcription polymerase chain reaction (RT-PCR). All RT-PCR positive' amplification products were confirmed by sequencing or analyzed and compared with those in GenBank known hMPV reference strain. RESULTS: hMPV was detected in 135 (5.2%) out of the 2613 children. The detected rate was significantly different between male and female (chi2 = 8.007, P = 0.003). The majority of the hMPV-positive patients (63.2%) were 0-1 year old infants. The majority of hMPV-positive patients were detected during spring season. Seasonal distribution showed that subtype A2b circulated predominantly in winter and spring, subtype B2 circulated predominantly in summer and spring. The most common genotype in 135 hMPV-positive patients were A and B in human subjects in Changsha. The predominant genotype of hMPV changed over the 3.5 year study period from genotype A2b to combined A2b and B2, and to B2. The 66 (48.9%) out of the 135 hMPV-positive patients were found to be co-infected with other respiratory viruses, and human bocavirus (HBoV) was the most common additional respiratory virus. CONCLUSION: These data suggest that some cases of acute lower respiratory infection in young children in Changsha area are related to hMPV and the majority of children infected with hMPV were less than 1 years old, the detected rate of boys was higher than that of girls. It circulated predominantly in spring. The subtype A2b genetic lineage and the subtype B1 genetic lineage of hMPV were revealed alternately in human subjects in Changsha area and the hMPV exhibited high co-infection rate with other respiratory viruses.