Identification and genetic characterization of a recently identified enterovirus C116 in China.

Enterovirus C116 (EV-C116) is a new member of the enterovirus C group which is closely associated with several infectious diseases. Although sporadic studies have detected EV-C116 in clinical samples worldwide, there is currently limited information available. In this study, two EV-C-positive fecal specimens were detected in apparently healthy children, which harbored low abundance, through meta-transcriptome sequencing. Based on the prototypes of several EV-Cs, two lineages were observed. Lineage 1 included many types that could not cause EV-like cytopathic effect in cell culture. Three genogroups of EV-C116 were divided in the maximum likelihood tree, and the two strains in this study (XZ2 and XZ113) formed two different lineages, suggesting that EV-C116 still diffuses worldwide. Obvious inter-type recombination events were observed in the XZ2 strain, with CVA22 identified as a minor donor. However, another strain (XZ113) underwent different recombination situations, highlighting the importance of recombination in the formation of EV-Cs biodiversity. The EV-C116 strains could propagate in rhabdomyosarcoma cell cultures at low titer; however, EV-like cytopathic effects were not observed. HEp-2, L20B, VERO, and 293T cell lines did not provide an appropriate environment for EV-C116 growth. These results challenge the traditional recognition of the uncultured nature of EV-C116 strains and explain the difficulty of clinical detection.

Changes in endemic patterns of respiratory syncytial virus infection in pediatric patients under the pressure of nonpharmaceutical interventions for COVID-19 in Beijing, China.

A series of nonpharmaceutical interventions (NPIs) was launched in Beijing, China, on January 24, 2020, to control coronavirus disease 2019. To reveal the roles of NPIs on the respiratory syncytial virus (RSV), respiratory specimens collected from children with acute respiratory tract infection between July 2017 and Dec 2021 in Beijing were screened by capillary electrophoresis-based multiplex PCR (CEMP) assay. Specimens positive for RSV were subjected to a polymerase chain reaction (PCR) and genotyped by G gene sequencing and phylogenetic analysis using iqtree v1.6.12. The parallel and fixed (paraFix) mutations were analyzed with the R package sitePath. Clinical data were compared using SPSS 22.0 software. Before NPIs launched, each RSV endemic season started from October/November to February/March of the next year in Beijing. After that, the RSV positive rate abruptly dropped from 31.93% in January to 4.39% in February 2020; then, a dormant state with RSV positive rates ≤1% from March to September, a nearly dormant state in October (2.85%) and November (2.98%) and a delayed endemic season in 2020, and abnormal RSV positive rates remaining at approximately 10% in summer until September 2021 were detected. Finally, an endemic RSV season returned in October 2021. There was a game between Subtypes A and B, and RSV-A replaced RSV-B in July 2021 to become the dominant subtype. Six RSV-A and eight RSV-B paraFix mutations were identified on G. The percentage of severe pneumonia patients decreased to 40.51% after NPIs launched. NPIs launched in Beijing seriously interfered with the endemic season of RSV.

The changed endemic pattern of human adenovirus from species B to C among pediatric patients under the pressure of non-pharmaceutical interventions against COVID-19 in Beijing, China.

BACKGROUND: Under the pressure of non-pharmaceutical interventions (NPIs) targeting severe acute respiratory syndrome coronavirus 2, the prevalence of human adenovirus (HAdV) was monitored before and after NPIs launched on Jan 24, 2020 in pediatric patients in Beijing, China. METHODS: Respiratory samples collected from children hospitalized with acute respiratory infections from Jan 2015 to Dec 2021 were screened by direct immunofluorescence test or capillary electrophoresis-based multiplex PCR assay. The hexon, penton base, and fiber genes were amplified from HAdV positive specimens, then sequenced. For HAdV typing, phylogenetic trees were built by MEGA X. Then clinical data of HAdV positive cases were collected. All data were evaluated using SPSS Statistics 22.0 software. RESULTS: A total of 16,097 children were enrolled and 466 (2.89%, 466/16,097) were HAdV-positive. The positive rates of HAdV varied, ranging from 4.39% (151/3,438) in 2018 to1.25% (26/2,081) in 2021, dropped from 3.19% (428/13,408) to 1.41% (38/2,689) from before to after NPIs launched (P < 0.001). There were 350 cases typed into nine types of species B, C, or E and 34 recorded as undetermined. Among them, HAdV-B3 (51.56%, 198/384) was the most prevalent types from 2015 to 2017, and HAdV-B7 (29.17%, 112/384) co-circulated with HAdV-B3 from 2018 to 2019. After NPIs launched, HAdV-B3 and B7 decreased sharply with HAdV-B7 undetected in 2021, while HAdV-C1 became the dominant one and the undetermined were more. CONCLUSIONS: The endemic pattern of HAdV changed in Beijing because of the NPIs launched for COVID-19. Especially, the dominant types changed from HAdV-B to HAdV-C.

Clinical characteristics of abruptly increased paediatric patients with Omicron BF.7 or BA.5.2 in Beijing.

BACKGROUND: The coronavirus disease 2019 outbreak has hit Beijing since mid-Nov, 2022, with soaring growth of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among children. Therefore, it is vital to determine the clinical manifestations of epidemic SARS-CoV-2 strains in paediatric patients. METHODS: In this study, nucleic acid tests (NATs) for SARS-CoV-2 were performed in paediatric outpatients with symptoms of acute respiratory tract infection during 18 Nov-6 Dec, 2022. Half of the outpatients positive for SARS-CoV-2 were randomly selected to screen for other respiratory pathogens, whereas those with low cycle threshold values in SARS-CoV-2 NATs were amplified and sequenced to determine the SARS-CoV-2 variants. Finally, children positive for SARS-CoV-2 with clinical information in detail were enrolled in a follow-up study to identify potential factors significantly associated with long recovery. RESULTS: Among 9625 paediatric outpatients tested for nucleic acid of SARS-CoV-2, 733 (7.62%, 733/9625) were identified as SARS-CoV-2 NAT positive, with only three (0.82%, 3/366) co-infected with other pathogens among 366 randomly selected patients, and 71 (62.83%) determined as Omicron subvariant BF.7 and 42 (37.22%) as BA.5.2 among 113 successfully sequenced. Among the 681 patients with complete clinical information, fever was the most common symptom (96.8%). In a follow-up study of 592 patients, 46.96% became asymptomatic on the third day and 65.71% on the fifth day. Only 1.7% of infected children experienced febrile seizures. Combined with abnormal C-reactive protein, a higher percentage of antibiotics administration was observed. More co-living members and longer duration of first symptoms served as independent risk factors for long-term recovery, especially in children vaccinated for SARS-CoV-2. CONCLUSIONS: BF.7 and BA.5.2 were the dominate Omicron subvariants and caused milder infections during the SARS-CoV-2 outbreak in Beijing. The number of co-living members and duration of first symptoms were independent risk factors for long-term recovery.

Prevalence and genomic analysis of t203-like G9 (G9-VI) rotaviruses circulating in children with gastroenteritis in Beijing, China.

Our previous surveillance revealed that t203-like G9 (tentatively designated subtype G9-VI) rotaviruses re-emerged in 2010 in Beijing and rapidly prevailed over the G9-III subtype (the most common G9 subtype globally) and previously predominant G genotypes over the following two years. G9-VI belongs to the VP7 evolutionary lineage VI, which includes unusual and sporadic human rotaviruses from China (t203) and Japan. To obtain insight into the epidemiology, evolution, and transmission advantages of G9-VI rotavirus, we performed follow-up surveillance (2014-2017) and whole-genome analysis of 12 representative G9 strains. The results showed that the G9 genotype was predominant (77.4%), with a marked increase in prevalence (previously 43.5%). Within the G9 genotype, subtype G9-VI accounted for the majority (98.3%) of cases. The most prevalent P-genotype was P[8] (93.7%), within which subtype P[8]b was rare (0.7%). Phylogenetically, the G9-VI subtype strains in this study clustered closely with contemporary emerging human rotaviruses from many other countries in VP7 lineage VI, indicating that this subtype is capable of spreading globally. These currently emerging G9-VI rotaviruses formed a distinct monophyletic subcluster when compared to early G9-VI rotaviruses. Furthermore, four specific amino acid substitutions and synonymous codon substitutions were observed in the VP7 genes between the current G9-VI and globally common G9-III rotaviruses. The remaining nine genes of all of the analyzed representative G9 strains, whether G9-VI or G9-III, combined with the P[8]a, P[8]b, or P[6] genotype and exhibited the same Wa-like backbone constellation.

Multiple RNA virus matrix proteins interact with SLD5 to manipulate host cell cycle.

The matrix protein of many enveloped RNA viruses regulates multiple stages of viral life cycle and has the characteristics of nucleocytoplasmic shuttling. We have previously demonstrated that matrix protein 1 (M1) of an RNA virus, influenza virus, blocks host cell cycle progression by interacting with SLD5, a member of the GINS complex, which is required for normal cell cycle progression. In this study, we found that M protein of several other RNA viruses, including VSV, SeV and HIV, interacted with SLD5. Furthermore, VSV/SeV infection and M protein of VSV/SeV/HIV induced cell cycle arrest at G0/G1 phase. Importantly, overexpression of SLD5 partially rescued the cell cycle arrest by VSV/SeV infection and VSV M protein. In addition, SLD5 suppressed VSV replication in vitro and in vivo, and enhanced type Ⅰ interferon signalling. Taken together, our results suggest that targeting SLD5 by M protein might be a common strategy used by multiple enveloped RNA viruses to block host cell cycle. Our findings provide new mechanistic insights for virus to manipulate cell cycle progression by hijacking host replication factor SLD5 during infection.

Reverse-Transcription Recombinase-Aided Amplification Assay for Rapid Detection of the 2019 Novel Coronavirus (SARS-CoV-2).

A novel coronavirus (SARS-CoV-2) was recently identified in patients with acute respiratory disease and spread quickly worldwide. A specific and rapid diagnostic method is important for early identification. The reverse-transcription recombinase-aided amplification (RT-RAA) assay is a rapid detection method for several pathogens. Assays were performed within 5-15 min as a one-step single tube reaction at 39 °C. In this study, we established two RT-RAA assays for the S and orf1ab gene of SARS-CoV-2 using clinical specimens for validation. The analytical sensitivity of the RT-RAA assay was 10 copies for the S and one copy for the orf1ab gene per reaction. Cross-reactions were not observed with any of the other respiratory pathogens. A 100% agreement between the RT-RAA and real-time PCR assays was accomplished after testing 120 respiratory specimens. These results demonstrate that the proposed RT-RAA assay will be beneficial as it is a faster, more sensitive, and more specific tool for the detection of SARS-CoV-2.

Reverse transcription genome exponential amplification reaction assay for rapid and universal detection of human rhinoviruses.

Human rhinoviruses (HRVs) have long been recognized as the cause of more than one-half of acute viral upper respiratory illnesses, and they are associated with more-serious diseases in children, such as asthma, acute otitis media and pneumonia. A rapid and universal test for of HRV infection is in high demand. In this study, a reverse transcription genome exponential amplification reaction (RT-GEAR) assay targeting the HRV 5' untranslated region (UTR) was developed for pan-HRV detection. The reaction was performed in a single tube in one step at 65 °C for 60 min using a real-time fluorometer (Genie(®)II; Optigene). The RT-GEAR assay showed no cross-reactivity with common human enteroviruses, including HEV71, CVA16, CVA6, CVA10, CVA24, CVB5, Echo30, and PV1-3 or with other common respiratory viruses including FluA H3, FluB, PIV1-4, ADV3, RSVA, RSVB and HMPV. With in vitro-transcribed RNA containing the amplified regions of HRV-A60, HRV-B06 and HRV-C07 as templates, the sensitivity of the RT-GEAR assay was 5, 50 and 5 copies/reaction, respectively. Experiments to evaluate the clinical performance of the RT-GEAR assay were also carried out with a panel of 143 previously verified samples, and the results were compared with those obtained using a published semi-nested PCR assay followed by sequencing. The tested panel comprised 91 HRV-negative samples and 52 HRV-positive samples (18 HRV-A-positive samples, 3 HRV-B-positive samples and 31 HRV-C-positive samples). The sensitivity and specificity of the pan-HRVs RT-GEAR assay was 98.08 % and 100 %, respectively. The kappa correlation between the two methods was 0.985. The RT-GEAR assay based on a portable Genie(®)II fluorometer is a sensitive, specific and rapid assay for the universal detection of HRV infection.

Epidemiological aspects of rotavirus and adenovirus in hospitalized children with diarrhea: a 5-year survey in Beijing.

BACKGROUND: Diarrhea caused by viruses is a global problem among young children. We investigated two of the most important agents, rotavirus and adenovirus, to provide epidemiological evidence for a better understanding of their role among children with acute diarrhea. METHODS: A total of 3147 hospitalized children were enrolled in the study during 2010 ~ 2014. Antigen testing for rotavirus and DNA testing for adenovirus were performed on stool specimens collected from participants. RESULTS: There were 1985 cases of community-acquired diarrhea (CAD) and 1162 cases of hospital-acquired diarrhea (HAD). A total of 692 cases (22.0 %) were positive for rotavirus. Rotavirus was detected in more children with HAD than in those with CAD (24.6 %; 286/1162 vs. 20.5 %; 406/1985). A total of 324 cases (10.3 %) were adenovirus positive. There was a significant difference between the CAD group and HAD group (9.5 %; 188/1985 vs. 11.7 %; 136/1162: χ 2 = 3.957, p = 0.047). Co-infection was found in only 35 children (1.11 %), and the co-infection rate was similar between the CAD and HAD groups (χ 2 = 1.174, p = 0.279). There was no association between sex and the detection rate of these viruses. The positive rate was significantly different for rotavirus among CAD cases (χ 2 = 27.979, p < 0.001) and for adenovirus (χ 2 = 34.362, p < 0.001) in the five age groups. Compared with the other four age groups (15.8-19.8 %), the prevalence of rotaviruses was highest among children aged 12-24 months (28.6 %). Adenovirus was detected in 3.6 % of neonates compared with 5.8 % of infants from 1 to 6 months old; this increased to 12.0-13.8 % in children over 6 months of age. In HAD cases, age differences were not found for rotavirus and adenovirus. Seasonal variation of rotavirus was observed, with peaks in November and December and with through in July and August; however, no clear seasonal pattern was found for adenovirus. CONCLUSION: Detection rates for rotavirus and adenovirus were significantly higher in children with HAD than those with CAD, but co-infection was very low. A high prevalence of rotavirus was identified in neonates with diarrhea. Vaccination for rotavirus gastroenteritis should be considered in neonates.

StructLane: Leveraging Structural Relations for Lane Detection.

Accurately detecting the lanes plays a significant role in various autonomous and assistant driving scenarios. It is a highly structured task as lanes in the 3D world are continuous and parallel to each other. While most existing methods focus on how to inject structural priors into the representation of each lane, we propose a StructLane method to further leverage the structural relations among lanes for more accurate and robust lane detection. To achieve this, we explicitly encode the structural relations using a set of relational templates in a learned structural space. We then employ the attention mechanism to enable interactions between templates and image features to incorporate structural relational priors. Our StructLane can be applied to existing lane detection methods as a plug-and-play module to improve their performance. Extensive experiments on the widely used CULane, TuSimple, and LLAMAS datasets demonstrate that StructLane consistently improves the performance of state-of-the-art models across all datasets and backbones. Visualization results also demonstrate the robustness of our StructLane compared with existing methods due to the leverage of structural relations. Codes will be released at https://github.com/lqzhao/StructLane.

Structure-Aware Cross-Modal Transformer for Depth Completion.

In this paper, we present a Structure-aware Cross-Modal Transformer (SCMT) to fully capture the 3D structures hidden in sparse depths for depth completion. Most existing methods learn to predict dense depths by taking depths as an additional channel of RGB images or learning 2D affinities to perform depth propagation. However, they fail to exploit 3D structures implied in the depth channel, thereby losing the informative 3D knowledge that provides important priors to distinguish the foreground and background features. Moreover, since these methods rely on the color textures of 2D images, it is challenging for them to handle poor-texture regions without the guidance of explicit 3D cues. To address this, we disentangle the hierarchical 3D scene-level structure from the RGB-D input and construct a pathway to make sharp depth boundaries and object shape outlines accessible to 2D features. Specifically, we extract 2D and 3D features from depth inputs and the back-projected point clouds respectively by building a two-stream network. To leverage 3D structures, we construct several cross-modal transformers to adaptively propagate multi-scale 3D structural features to the 2D stream, energizing 2D features with priors of object shapes and local geometries. Experimental results show that our SCMT achieves state-of-the-art performance on three popular outdoor (KITTI) and indoor (VOID and NYU) benchmarks.

Clinical characteristics and genetic analysis of children with Omicron BF.7.14 type novel coronavirus-related acute necrotizing encephalopathy.

Background: To explore the clinical characteristics, etiological factors, and clinical-related genetic variant of children with acute necrotizing encephalopathy (ANE) related to the Omicron BF.7.14 novel coronavirus. Methods: Genomic variations were detected through whole exome sequencing. Additionally, we summarized the clinical data to explore the inheritance patterns associated with novel coronavirus-related ANE. Results: This study included four patients (2 males and 2 females) with an average age of 2.78 ± 1.93 years. All the patients had prodromal symptoms of Omicron BF.7.14 virus infection, and exhibited symptoms such as altered consciousness, seizures and cognitive/language disturbances. Cranial MRI scans revealed damage to the thalamus, basal ganglia and brainstem. The cerebrospinal fluid (CSF) cell counts were nearly normal, but protein level in CSF increased significantly. Genetic analysis revealed a novel truncated variant of CRMP2 gene in one patient who suffered more severe coma score and prognosis and dead in the later stages. All children exhibited a decrease in the absolute count of T lymphocytes, helper T cells, suppressor T cells, and NK cells to varying degrees. Furthermore, levels of cytokines, including IL-1 ß, IL-5, IL-6 and IL-8 were significantly elevated in the CSF, especially in patient with truncated variant of CRMP2 gene. Conclusion: The Omicron BF.7.14 type novel coronavirus can lead to ANE, characterized by T cell immunosuppression and a significant increase in cytokine levels in the CSF. The truncated variation of CRMP2 gene may affect the prognosis of ANE by affecting the migration of cerebral T cells.

Synergetic association between coxsackievirus A16 genotype evolution and recombinant form shifts.

Coxsackievirus A16 (CVA16) is a major pathogen that causes hand, foot, and mouth disease (HFMD). The recombination form (RF) shifts and global transmission dynamics of CVA16 remain unknown. In this retrospective study, global sequences of CVA16 were retrieved from the GenBank database and analyzed using comprehensive phylogenetic inference, RF surveys, and population structure. A total of 1,663 sequences were collected, forming a 442-sequences dataset for VP1 coding region analysis and a 345-sequences dataset for RF identification. Based on the VP1 coding region used for serotyping, three genotypes (A, B, and D), two subgenotypes of genotype B (B1 and B2), and three clusters of subgenotype B1 (B1a, B1b, and B1c) were identified. Cluster B1b has dominated the global epidemics, B2 disappeared in 2000, and D is an emerging genotype dating back to August 2002. Globally, four oscillation phases of CVA16 evolution, with a peak in 2013, and three migration pathways were identified. Europe, China, and Japan have served as the seeds for the global transmission of CVA16. Based on the 3D coding region of the RFs, five clusters of RFs (RF-A to -E) were identified. The shift in RFs from RF-B and RF-C to RF-D was accompanied by a change in genotype from B2 to B1a and B1c and then to B1b. In conclusion, the evolution and population dynamics of CVA16, especially the coevolution of 3D and VP1 genes, revealed that genotype evolution and RF replacement were synergistic rather than stochastic.

High-Frequency Recombination of Human Adenovirus in Children with Acute Respiratory Tract Infections in Beijing, China.

Recombination events in human adenovirus (HAdV) have led to some new highly pathogenic or infectious types. It is vital to monitor recombinant HAdVs, especially in children with acute respiratory tract infections (ARIs). In the retrospective study, HAdV positive specimens were collected from pediatric patients with ARIs during 2015 to 2021, then typed by sequence analysis of the penton base, hexon and fiber gene sequence. For those with inconsistent typing results, a modified method with species-specific primer sets of a fiber gene sequence was developed to distinguish co-infections of different types from recombinant HAdV infections. Then, plaque assays combined with meta-genomic next-generation sequencing (mNGS) were used to reveal the HAdV genomic characteristics. There were 466 cases positive for HAdV DNA (2.89%, 466/16,097) and 350 (75.11%, 350/466) successfully typed with the most prevalent types HAdV-B3 (56.57%, 198/350) and HAdV-B7 (32.00%, 112/350), followed by HAdV-C1 (6.00%, 21/350). Among 35 cases (7.51%, 35/466) with inconsistent typing results, nine cases were confirmed as co-infections by different types of HAdVs, and 26 cases as recombinant HAdVs in six genetic patterns primarily clustered to species C (25 cases) in pattern 1-5, or species D (1 case) in pattern 6. The novel recombinant HAdV of species D was identified with multiple recombinant events among HAdV-D53, HAdV-D64, and HAdV-D8, and officially named as HAdV-D115. High-frequency recombination of HAdVs in six genetic recombination patterns were identified among children with ARIs in Beijing. Specifically, there is a novel Adenovirus D human/CHN/S8130/2023/115[P22H8F8] designed as HAdV D115.

Epidemiological Characteristics of Human Parainfluenza Viruses Infections - China, 2019-2023.

Introduction: A retrospective study based on sentinel surveillance was conducted in 10 provincial-level administrative divisions (PLADs) in China to enhance the understanding of the epidemiological characteristics of human parainfluenza viruses (HPIVs). Methods: From January 2019 to June 2023, respiratory specimens were collected from individuals with acute respiratory infections (ARIs) and screened for four HPIVs serotypes and other common respiratory viruses using multiplex real-time polymerase chain reaction (PCR). This study analyzed the association of HPIVs infections with seasonal patterns, geographical distribution, demographic profiles, clinical features, and co-infection status. Results: During the study period, a total of 12,866 ARIs were included. The overall detection rate of HPIVs was 6.15%, varying from 5.04% in 2022 to 9.70% in 2020. The median age of HPIVs-infected patients was 3 years. HPIV2 was more prevalent among individuals aged 5-17 years (42.57%), while HPIV4 was more common in those over 65 years (12.24%). HPIV3 (54.16%) and HPIV1 (27.18%) were the predominant serotypes, and their prevalence exhibited significant seasonal fluctuations post- coronavirus disease 2019 (COVID-19) pandemic. The peak of HPIV3 shifted three months later in 2020 compared to 2019 and returned to a summer peak thereafter. Two peaks of HPIV1 were observed in 2021 following the peak of HPIV3. Additionally, co-infections were frequent in HPIVs cases (overall rate: 22.12%), with human rhinovirus being the most common co-infecting virus. Conclusions: The prevalence of HPIVs in China was predominantly due to HPIV3 and HPIV1, and their seasonal patterns were altered by pandemic restrictions. Hence, continuous surveillance of HPIVs is essential.

Genetic Evolution and Variation of Human Adenovirus Serotype 31 Epidemic Strains in Beijing, China, during 2010-2022.

Human adenovirus serotype 31 (HAdV-31) is closely associated with gastroenteritis in children and can cause fatal systemic disseminated diseases in immunocompromised patients. The lack of genomic data for HAdV-31, especially in China, will greatly limit research on its prevention and control. Sequencing and bioinformatics analyses were performed for HAdV-31 strains from diarrheal children in Beijing, China, during 2010-2022. Three capsid protein genes (hexon, penton, and fiber) were obtained in 37 cases, including one in which the whole genome was sequenced. HAdV-31 strains clustered into three distinct clades (I-III) in a phylogenetic tree constructed based on concatenated genes and the whole genome; the endemic strains only gathered into clade II, and most of the reference strains clustered into clade I. Compared with penton and hexon, fiber had a faster evolutionary rate (1.32 × 10-4 substitutions/site/year), an earlier divergence time (1697), lower homology (98.32-100% at the amino acid level), and greater genetic variation (0.0032). Four out of the six predicted positive selection pressure codons were also in the knob of fiber. These results reveal the molecular evolution characteristics and variations of HAdV-31 in Beijing, and fiber may be one of the main evolution driving forces.

Multicenter evaluation of the Acaruiter Respiratory Panel for diagnosis of respiratory tract infections in Chinese children.

IMPORTANCE: Compared to multiplex PCR assays that are available in the Chinese market, the Acaruiter Respiratory Panel (fluorescent PCR) covers a wider range of pathogens including eight viruses, five bacteria, Mycoplasma pneumoniae and Chlamydia pneumoniae, and has high accuracy and effectiveness in the detection of pathogens. This is the first study to evaluate the performance of the Acaruiter Respiratory Panel. This regent may be a promising assay for comprehensive testing for respiratory pathogens from nasopharyngeal swab specimens in Chinese children.

Human bocavirus 1 and 2 genotype-specific antibodies for rapid antigen testing in pediatric patients with acute respiratory infections.

BACKGROUND: Previous serological studies of human bocavirus (HBoV) 1 could not exclude cross-reactivity with the other three HBoVs, particularly HBoV2. METHODS: To search for genotype-specific antibodies against HBoV1 and HBoV2, the divergent regions (DRs) located on the major capsid protein VP3 were defined through viral amino acid alignment and structure prediction. DR-deduced peptides were used as antigens to harvest corresponding anti-DR rabbit sera. To determine their genotype specificities for HBoV1 and HBoV2, these sera samples were used as antibodies against the antigens VP3 of HBoV1 and HBoV2 (expressed in Escherichia coli) in western blotting (WB), enzyme-linked immunosorbent assay (ELISA), and bio-layer interferometry (BLI) assays. Subsequently, the antibodies were evaluated with clinical specimens from pediatric patients with acute respiratory tract infection by indirect immunofluorescence assay (IFA). RESULTS: There were four DRs (DR1-4) located on VP3 with different secondary and tertiary structures between HBoV1 and HBoV2. Regarding the reactivity with VP3 of HBoV1 or HBoV2 in WB and ELISA, high intra-genotype cross-reactivity of anti-HBoV1 or HBoV2 DR1, DR3, and DR4, but not anti-DR2, was observed. Genotype-specific binding capacity of anti-DR2 sera was confirmed by BLI and IFA, in which only anti-HBoV1 DR2 antibody reacted with HBoV1-positive respiratory specimens. CONCLUSION: Antibodies against DR2, located on VP3 of HBoV1 or HBoV2, were genotype specific for HBoV1 and HBoV2, respectively.

Manganese Mineralization of Pathogenic Viruses as a Universal Vaccine Platform.

Biomimetic viral mineralization improves viral vaccine stability and immunogenicity using inorganic metals such as Ca, Al, or Fe. Mn is a metal found in high concentrations in mammalian tissues; however, under natural or laboratory conditions, Mn mineralization by medical viruses has yet to be established. Herein, a single IAV particle is successfully encapsulated with manganese phosphate (MnP) under specific conditions using the human influenza A virus (IAV). MnP-mineralized IAVs (IAV@Mn) exhibited physiochemical and in vitro properties similar to Ca-mineralized IAVs. In animal models, IAV@Mn shows limited replication in immune-competent cells and a significant attenuation compared to naïve cells. Moreover, a single-dose vaccination with IAV@Mn induced robust humoral and cellular immune responses and conferred significant protection against a wild-type IAV challenge in mice. Thus, Mn mineralization in pathogenic viruses provides a rapid and universal strategy for generating an emergency vaccine in response to emerging viruses.

[Clinical analysis of 47 children with types 3 and 7 adenovirus pneumonia].

OBJECTIVE: To explore the clinical features of types 3 and 7 adenovirus pneumonia in children and compare the difference between two types. METHODS: A total of 47 patients with adenovirus pneumonia at our hospital from January 2009 to June 2011 were reviewed. According to the serological types, they were divided into two groups: type 3 (n = 19) and type 7 (n = 28). Two groups were analyzed statistically with regards to age, gender, clinical presentation, critical scores, laboratory examinations, radiographic findings, lung function changes, complications and prognosis respectively. RESULTS: For types 3 and 7 adenovirus pneumonia, the median age of onset were 1.8 and 1.1 years old respectively. The male-to-female ratio were 14:5 and 20:8 respectively. As compared with type 3, type 7 had the longer fever time ((18 ± 10) vs (11 ± 7)days, P = 0.010), the higher critical proportion (13/28 (46.4%) vs 3/19 (15.8%), P = 0.031), the longer hospital stays ((28 ± 17) vs (15 ± 6) days, P = 0.003)), the higher proportion of involved lung ≥ 3 lobes (22/28 (78.6%) vs 4/19 (21.1%), P = 0.000), the lower oxygenation index ((192 ± 85) vs (256 ± 79) mm Hg,1 mm Hg = 0.133 kPa, P = 0.011), the higher proportion of mechanical ventilation (17/28 (60.7%) vs 5/19 (26.3%), P = 0.020) and the higher proportion of multiple organ dysfunction syndrome (16/28 (57.1%) vs 5/19 (26.3%), P = 0.037). In type 7, organ dysfunction was more obvious, particularly in nervous system, blood system and enzyme changes. Three cases of type 7 had pulmonary sequela with small airway disease. CONCLUSION: With more severe clinical manifestations, laboratory parameters and imaging data than type 3, type 7 adenovirus pneumonia in children is more likely to cause pulmonary sequela.