A highly acute disease characterized as visceral gout broke out in Muscovy ducklings in Henan province (China) in June 2020, with a mortality rate of up to 61%. In this study, common pathogenic agents were screened using reverse-transcription polymerase chain reaction or polymerase chain reaction. The results found the novel goose astrovirus (GoAstV) to be the pathogenic agent. We isolated the GoAstV, which has been designated as HNNY0620, using the Leghorn male chicken hepatocellular carcinoma (LMH) cell line and sequenced the complete genome. The phylogenetic tree showed that the amino acid (aa) sequences of ORF1a and ORF2 and the completed nucleotide sequences of the HNNY0620 strain were clustered in the GoAstV-I clade. ORF1a aa and whole-genome sequences were genetically close to TAstV-2 and DHV-3, whereas the ORF2 aa sequences were clustered with TAstV-2 and DHV2. Both the duck-origin GoAstVs and HNNY0620 harbored some special mutations, but ORF1a in 700 (I/T), ORF1b in 288 (F/L), and ORF2 in 306 (A/T) were only found in HNNY0620. These results suggest that the host range of GoAstV is diffusing, which can potentially affect other waterfowl.

In this study, a rapid, specific, and sensitive detection assay for Mycoplasma synoviae (MS) was established using a polymerase spiral reaction (PSR)

The natural infections of HoBi‐like pestiviruses in cattle have been reported in South America, Europe and Asia. In China, although the detections of HoBi‐like pestivirus have been reported, the epidemiological investigation was limited. From January 2014 to October 2015, several flocks of sheep/goats in Henan province in central China suffered respiratory diseases which were recovered slowly after antibiotics treatment. To test whether it is the HoBi‐like pestivirus caused this symptom, 49 serum samples and 22 nasal swabs were then collected for analysis by serology and RT‐PCR. Serological result revealed that prevalence of pestivirus in small ruminants was 12.2% (6/49) in central China. Sequence analysis of partial 5′‐UTR nucleotides of pestivirus‐positive samples suggested that HoBi‐like pestivirus might have circulated in sheep/goats of China for a period and have evolved into new genotype clusters. It is apparent that the study provides the molecular evidence of natural infections in goat/sheep species with HoBi‐like pestiviruses in China.

Infectious bronchitis (IB), caused by avian IB virus (IBV), is an acute and highly contagious disease of chickens. From 2016 to 2018, 56 IBV strains were isolated and identified from clinical samples obtained from various chicken farms located in central China. The S1 sequencing of these strains revealed nucleotide and amino acid identities of 70.2 to 100% and 62.6 to 100%, respectively, compared with those of reference strains. Phylogenetic analysis indicated that the genotypes of the isolates included GI-13 (4/91), GI-7 (TW-I), GI-24 (Mass), GI-19 (QX), and GI-18 (LDT3-A), with GI-19 (QX) being the predominant genotype. Meanwhile, GI-13 (4/91) was the second most dominant genotype in Henan Province, whereas it was GI-7 (TW-I) in Hunan and Hubei provinces. Recombination analysis of 3 variant strains showed that CK/CH/HeN/20160113 might be a recombination of LDT3-A- and QX-type strains and that CK/CH/HeN/20160316 might be a recombination of Italy-02-type strain and CK-CH-LJS08II. The predicted tertiary structure between CK/CH/HeN/20160113 and LDT3-A-type strain revealed that the novel 336 (L-P) and 455 (S-A) mutations changed the structure from an alpha helix to a random crimp. In addition, the 275 (Y-F) site reduced the length of the β-sheet, whereas the site 353 (A-T) extended the β-sheet. These findings suggested that GI-19 (QX) remains the predominant genotype in central China, and a locally determined complex genotype associated with variable clinical symptoms exists related to gene recombination and mutations.