The genome sequence analysis of H5N1 avian influenza A virus isolated from the outbreak among poultry populations in Thailand

In this report, the genome of the Thai avian influenza virus A (H5N1); A/Chicken/Nakorn-Pathom/Thailand/CU-K2/04, isolated from the Thai avian influenza A (AI) epidemic during the early of 2004 was sequenced. Phylogenetic analyses were performed in comparison to AI viruses from Hong Kong 1997 outbreaks and other AI (H5N1) isolates reported during 2001-2004. Molecular characterization of the Thai AI (H5N1) HA gene revealed a common characteristic of a highly pathogenic AI (HPAI), a 20-codon deletion in the neuraminidase gene, a 5-codon deletion in the NS gene and polymorphisms of the M2 and PB2 genes. Moreover, the HA and NA genes of the Thai AI displayed high similarity to those of the AI viruses isolated from human cases during the same epidemic. Finally, our results demonstrated that the Thai AI emerged as a member of 2000's AI lineage with most of the genetic sequences closely related to the Influenza A/Duck/China/E319.2/03 (H5N1).     

Receptor-binding properties of modern human influenza viruses primarily isolated in Vero and MDCK cells and chicken embryonated eggs

To study the receptor specificity of modern human influenza H1N1 and H3N2 viruses, the analogs of natural receptors, namely sialyloligosaccharides conjugated with high molecular weight (about 1500 kDa) polyacrylamide as biotinylated and label-free probes, have been used. Viruses isolated from clinical specimens were grown in African green monkey kidney (Vero) or Madin-Darby canine kidney (MDCK) cells and chicken embryonated eggs. All Vero-derived viruses had hemagglutinin (HA) sequences indistinguishable from original viruses present in clinical samples, but HAs of three of seven tested MDCK-derived isolates had one or two amino acid substitutions. Despite these host-dependent mutations and differences in the structure of HA molecules of individual strains, all studied Vero- and MDCK-isolated viruses bound to Neu5Ac alpha2-6Galbeta1-4GlcNAc (6'SLN) essentially stronger than to Neu5Acalpha2-6Galbeta1-4Glc (6'SL). Such receptor-binding specificity has been typical for earlier isolated H1N1 human influenza viruses, but there is a new property of H3N2 viruses that has been circulating in the human population during recent years. Propagation of human viruses in chicken embryonated eggs resulted in a selection of variants with amino acid substitutions near the HA receptor-binding site, namely Gln226Arg or Asp225Gly for H1N1 viruses and Leu194Ile and Arg220Ser for H3N2 viruses. These HA mutations disturb the observed strict 6'SLN specificity of recent human influenza viruses.     

Testing human sera for antibodies against avian influenza viruses: Horse RBC hemagglutination inhibition vs. microneutralization assays

BACKGROUND: The hemagglutination inhibition (HI) assay is a frequently used method to screen human sera for antibodies against influenza A viruses. Because HI has relatively poor sensitivity in detecting antibodies against avian influenza A strains, a more complicated microneutralization (MN) assay is often preferred. Recent research suggests that the sensitivity of the HI assay can be improved by switching from the traditionally used turkey, guinea pig, human, or chicken RBCs to horse RBCs. OBJECTIVE: To evaluate the performance of the horse RBC HI when screening for human antibodies against avian influenza types H3, H4, H5, H6, H7, H9, H11, and H12. STUDY DESIGN: We evaluated the reproducibility of horse RBC HI and its agreement with MN results using sera from people exposed or not exposed to wild and domestic birds. RESULTS: The horse RBC HI assay had high reliability (90%-100%) and good agreement with MN assay results (52%-100%). CONCLUSION: The horse RBC HI assay is reliable, less expensive, less complex, and faster than the MN assay. While MN will likely remain the gold standard serologic assay for avian viruses, the horse RBC HI assay may be very useful as a screening assay in large-scale epidemiologic studies.     

Histopathological characterization of the naturally occurring hepatotropic virus infections of nude mice

In the last ten years the mutant athymic nude mouse has been used by many researchers as a model for studying pathological conditions in an immunodeficient host. A major problem with such mice is their susceptibility to viral infections indigenous to murine stocks, such as the hepatotropic mouse coronaviruses. In an effort to define the hepatotropic virus diseases indigenous to nude mice this paper details the pathogenesis and associated comparative histopathology of three common strains of mouse hepatitis virus, reovirus 3 and murine cytomegalovirus in the nude mouse.     

Rapid detection of respiratory viruses using mixtures of monoclonal antibodies on shell vial cultures.

Eleven hundred and thirty-three clinical specimens submitted to the laboratory for diagnosis of respiratory virus infections were tested by direct immunofluorescence (DIF) for respiratory syncytial virus (RSV), by shell vial culture, and by conventional cell culture. The shell vial cultures were stained with 8 different monoclonal antibodies both 1 day and 3-7 days after inoculation. In order to limit the cost and the workload, mixtures of monoclonal antibodies were used. Coverslips with HEp-2 cells were incubated with a mixture of FITC-labeled monoclonal antibody to RSV and nonlabeled monoclonal antibody to adenovirus. When no RSV positive IF staining was observed after the first incubation step, the same coverslip was incubated once more with FITC-labeled anti-mouse antibody. A positive reaction at this stage indicated the presence of adenovirus. Similarly, cultures of tertiary monkey kidney cells were investigated with a mixture of two FITC-labeled monoclonals to the influenza viruses A and B and three nonlabeled monoclonals to the parainfluenza viruses 1, 2 and 3. If influenza virus or parainfluenza virus was detected, the exact type was determined by staining different parts of a duplicate coverslip. Shell vial cultures for cytomegalovirus (CMV) were always performed separately on human embryonic lung fibroblasts. Using this approach, we detected RSV (n = 248), CMV (n = 42), parainfluenza virus (n = 31), influenza virus (n = 28), and adenovirus (n = 6), in most cases after only one day of culture. For RSV, the sensitivity of the shell vial method was too low (74%) to allow omission of DIF (sensitivity 95%).(ABSTRACT TRUNCATED AT 250 WORDS)     

重型肝炎中甲、乙型肝炎病毒合并感染的探讨

报告经血清免疫学抗HAVIgM、抗-HBcIgM、HBV-DNA、HBsAg/IgM复合物以及乙肝三种抗原抗体系统检测48例重型肝炎中甲、乙型肝炎病毒感染情况。结果:31例为HBV感染,1例为HAV感染,1例未定型,15例(31.25％)为甲、乙型合并感染(混合感染7例、重叠感染8例)。15例中亚急性10例、慢性5例;死亡或恶化10例,与同期“单纯”感染的重肝比较,包括主要临床生化指标均无显著差异。有7例患者病程中有近期出现“急黄肝”症状的历史,随后病情突然加重;1例发生在住院期间,且血清抗-HAVIgM转阳,最后死亡。认为合并感染可使部分急、慢性肝炎病情加重,甚至发展成重型。应注意发现。     

Human Milk Virome Analysis: Changing Pattern Regarding Mode of Delivery,Birth Weight,and Lactational Stage

The human milk (HM) microbiota is a significant source of microbes that colonize the infant gut early in life. The aim of this study was to compare transient and mature HM virome compositions, and also possible changes related to the mode of delivery, gestational age, and weight for gestational age. Overall, in the 81 samples analyzed in this study, reads matching bacteriophages accounted for 79.5% (mainly Podoviridae, Myoviridae, and Siphoviridae) of the reads, far more abundant than those classified as eukaryotic viruses (20.5%, mainly Herpesviridae). In the whole study group of transient human milk, the most abundant families were Podoviridae and Myoviridae. In mature human milk, Podoviridae decreased, and Siphoviridae became the most abundant family. Bacteriophages were predominant in transient HM samples (98.4% in the normal spontaneous vaginal delivery group, 92.1% in the premature group, 89.9% in the C-section group, and 68.3% in the large for gestational age group), except in the small for gestational age group (only ~45% bacteriophages in transient HM samples). Bacteriophages were also predominant in mature HM; however, they were lower in mature HM than in transient HM (71.7% in the normal spontaneous vaginal delivery group, 60.8% in the C-section group, 56% in the premature group, and 80.6% in the large for gestational age group). Bacteriophages still represented 45% of mature HM in the small for gestational age group. In the transient HM of the normal spontaneous vaginal delivery group, the most abundant family was Podoviridae; however, in mature HM, Podoviridae became less prominent than Siphoviridae. Myoviridae was predominant in both transient and mature HM in the premature group (all C-section), and Podoviridae was predominant in transient HM, while Siphoviridae and Herpesviridae were predominant in mature HM. In the small for gestational age group, the most abundant taxa in transient HM were the family Herpesviridae and a species of the genus Roseolovirus. Bacteriophages constituted the major component of the HM virome, and we showed changes regarding the lactation period, preterm birth, delivery mode, and birth weight. Early in life, the HM virome may influence the composition of an infant’s gut microbiome, which could have short- and long-term health implications. Further longitudinal mother–newborn pair studies are required to understand the effects of these variations on the composition of the HM and the infant gut virome.     

Precision Tracing of Household Dengue Spread Using Inter- and Intra-Host Viral Variation Data,Kamphaeng Phet,Thailand

Dengue control approaches are best informed by granular spatial epidemiology of these viruses, yet reconstruction of inter- and intra-household transmissions is limited when analyzing case count, serologic, or genomic consensus sequence data. To determine viral spread on a finer spatial scale, we extended phylogenomic discrete trait analyses to reconstructions of house-to-house transmissions within a prospective cluster study in Kamphaeng Phet, Thailand. For additional resolution and transmission confirmation, we mapped dengue intra-host single nucleotide variants on the taxa of these time-scaled phylogenies. This approach confirmed 19 household transmissions and revealed that dengue disperses an average of 70 m per day between households in these communities. We describe an evolutionary biology framework for the resolution of dengue transmissions that cannot be differentiated based on epidemiologic and consensus genome data alone. This framework can be used as a public health tool to inform control approaches and enable precise tracing of dengue transmissions.     

Multisystem Inflammatory Syndrome in Adults after Mild SARS-CoV-2 Infection,Japan

In Japan, a 51-year-old man had minimally symptomatic severe acute respiratory syndrome coronavirus 2 infection. Multisystem inflammatory syndrome was diagnosed ≈5 weeks later; characteristics included severe inflammation, cardiac dysfunction, and IgG positivity. Clinicians should obtain detailed history and examine IgG levels for cases of inflammatory disease with unexplained cardiac decompensation.