Neotropical Bats from Costa Rica harbour Diverse Coronaviruses

Bats are hosts of diverse coronaviruses (CoVs) known to potentially cross the host–species barrier. For analysing coronavirus diversity in a bat species‐rich country, a total of 421 anal swabs/faecal samples from Costa Rican bats were screened for CoV RNA‐dependent RNA polymerase (RdRp) gene sequences by a pancoronavirus PCR. Six families, 24 genera and 41 species of bats were analysed. The detection rate for CoV was 1%. Individuals (n = 4) from four different species of frugivorous (Artibeus jamaicensis, Carollia perspicillata and Carollia castanea) and nectivorous (Glossophaga soricina) bats were positive for coronavirus‐derived nucleic acids. Analysis of 440 nt. RdRp sequences allocated all Costa Rican bat CoVs to the α‐CoV group. Several CoVs sequences clustered near previously described CoVs from the same species of bat, but were phylogenetically distant from the human CoV sequences identified to date, suggesting no recent spillover events. The Glossophaga soricina CoV sequence is sufficiently dissimilar (26% homology to the closest known bat CoVs) to represent a unique coronavirus not clustering near other CoVs found in the same bat species so far, implying an even higher CoV diversity than previously suspected.     

安徽省鸡腺胃型传染性支气管炎的研究初报

1997年6月份以来,安徽省淮南等地鸡群流行一种以腺胃病变为主要特征的传染病。经9日龄鸡胚接种病鸡的肝、脾、腺胃等病料分离到的HN毒株,在鸡胚中可稳定传至12代,具有规律性死亡和胚胎病变,ELD50为109.75。用HN鸡胚尿囊液毒人工感染试验鸡,能引起与自然病例相同的临床症状和典型病变。HN鸡胚尿囊液经负染后电镜观察,具有典型的冠状病毒形态。病毒液经胰蛋白酶处理后能凝集鸡红细胞,IBV单抗ELISA检测呈强阳性反应。应用分离毒研制的油乳剂疫苗经试验和临床应用表明有良好的保护作用。研究结果初步表明,HN每株为IBV成员。     

鸡传染性腺胃病病原T95株的分离与鉴定

自某疫区的鸡腺胃病鸡群中分离到Ｔ９５毒株,在ＳＰＦ鸡胚稳定传代至８代,具有规律性死亡和典型胚胎病变特征,Ｔ９５株感染鸡胚尿囊液提纯的病毒液经负染后电镜观察：病毒粒子大小为８０￣１６０ｎｍ,有囊膜,表面具纤突,呈典型冠状病毒形态。病毒对热和氯仿敏感,耐酸,能抵抗１％胰酶,无直接血凝性,但经卵磷脂酶Ｃ处理后能凝结鸡红细胞。经单抗介导的ＥＬＩＳＡ检测,Ｔ９５株与ＩＢＶ有密切的血清学关系。     

Unveiling patterns of viral pathogen infection in free-ranging carnivores of northern Portugal using a complementary methodological approach

Pathogen surveillance in free-ranging carnivores presents challenges due to their low densitie and secretive nature. We combined molecular and serological assays to investigate infections by viral pathogens (Canine parvovirus (CPV), Canine distemper virus (CDV) and Canine coronavirus (CCoV)) in Portuguese carnivores (Canis lupus, Vulpes vulpes, Lutra lutra, Martes foina, M. martes, Meles meles, and Genetta genetta) over a period of 16 years. Additionally we explored spatio-temporal patterns of virus occurrence in Canis lupus. Our study identified CPV DNA in all carnivore species with an overall prevalence of 91.9 %. CPV was detected in all sampled years and seasons in Canis lupus, supporting its enzootic nature. CDV RNA was mainly detected in the Canidae family, with viral nucleic acid recorded between 2005 and 2008 with a peak prevalence of 67 % among the wolf population, followed by a sharp decline, suggesting an epizootic behaviour of the virus. Antibodies show that mustelids and viverrids were often exposed to CDV. CCoV was first recorded by molecular methods in wolf samples in 2002, remaining in the wolf populations with marked fluctuations over time. The dual serological and molecular approach provided important epidemiological data on pathogens of wild carnivores in Portugal. These programmes should also include monitoring of other potential reservoir hosts such as domestic cats and dogs.     

鸡传染性支气管炎分子生物学诊断研究

综述寡核苷酸指纹图谱分析、RT-PCR、RFLP、核酸探针、单克隆抗体技术,及基因表达技术在鸡传染性支气管炎(IB)分子生物学诊断方面的研究与应用。     

抗击新冠肺炎疫情期间双季杂交早稻高产栽培技术

本文阐述了杂交早稻高产栽培技术,包括培育壮秧、合理施肥、科学管水和病虫害防治等方面内容,为当前新型冠状肺炎疫情期间的杂交早稻生产做好技术指导。     

An enzyme-linked immunosorbent assay using canine coronavirus-infected CRFK cells as antigen for detection of anti-coronavirus antibody in cat

From the reasons that canine coronavirus (CCV) grows more efficiently than feline coronavirus in a cell culture and they are mutually related in their antigenicities, an enzyme-linked immunosorbent assay (ELISA) using CCV-infected feline kidney (CRFK) cells as substrate antigens was developed for detection of anti-coronavirus antibodies in cats. It was indispensable for generating coronavirus-specific ELISA antibody activities that the sample was applied to the mock-infected, normal CRFK cells in parallel with the CCV-infected cells and then the optical density values given by the mock-infected cell antigen were subtracted from those given by the virus-infected cell antigen. On the basis of ELISA antibody titers obtained in sera from the cats experimentally infected with CCV and from the spontaneous feline infectious peritonitis (FIP) cases, the ELISA described in the present study was found to be applicable as a simple and easy serologic test which was able to detect anti-coronavirus antibodies as efficiently as the indirect immunofluorescence assay with homologous FIP virus.     

Analysis of pathogenic biology of SARS-associated coronavirus and its implication

Severe acute respiratory syndrome (SARS) is the first new epidemic of the twenty-first century. A novel coronavirus (SARS-CoV) has been identified as the causative agent of SARS. The genome of SARS-CoV has 29 727 nucleatides in length. The genome organization, with 11 open reading frames, is similar to that of coronaviruses. Phylogenetic analyses and sequence comparisons showed that SARS-CoV is not closely related to any of the known coronaviruses, indicating neither a mutant nor recombinant of wel-characterized coronaviruses. It is a complete new coronavirus from nonhuman host. Pathological studies show that severe immune response, associated to cytokine dysregulation, may be related to the lung damage of fatal SRAS. Recombination of genomes of wild-type strains with vaccine coronavirus is a potential risk associated with the application of living attenuated coronavirus vaccines. The proteinases, controlling the activities of the SARS-CoV replication, and spike protein, involved in viral entry and pathogenesis, represent at ractive targets of anti-SARS drug development. Comparative full-length genome sequence analysis of 14 SARS coronavirus isolates suggests a remarkable genetic conservation of the virus. Anti-SARS vaccine and drug development wil benefit from this genet ic conservation.SARS-CoV is not likely to change rapidly and thus may not readily mutate to a benign infection. The progress in anti-SARS research has been impressive. However, one of the most effective tools in the control of the SARS is quickly tracing and isolating the contacts of stricken patients before they spread the virus further.