College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, China.
Transbound Emerg Dis. 2019 Mar;66(2):763-775. doi: 10.1111/tbed.13081. Epub 2018 Dec 5.
Feline infectious peritonitis (FIP) is a fatal infectious disease of wild and domestic cats, and the occurrence of FIP is frequently reported in China. To trace the evolution of type I and II feline coronavirus in China, 115 samples of ascetic fluid from FIP-suspected cats and 54 fecal samples from clinically healthy cats were collected from veterinary hospitals in China. The presence of FCoV in the samples was detected by RT-PCR targeting the 6b gene. The results revealed that a total of 126 (74.6%, 126/169) samples were positive for FCoV: 75.7% (87/115) of the FIP-suspected samples were positive for FCoV, and 72.2% (39/54) of the clinically healthy samples were positive for FCoV. Of the 126 FCoV-positive samples, 95 partial S genes were successfully sequenced. The partial S gene-based genotyping indicated that type I FCoV and type II FCoV accounted for 95.8% (91/95) and 4.2% (4/95), respectively. The partial S gene-based phylogenetic analyses showed that the 91 type I FCoV strains exhibited genetic diversity; the four type II FCoV strains exhibited a close relationship with type II FCoV strains from Taiwan. Three type I FCoV strains, HLJ/HRB/2016/10, HLJ/HRB/2016/11 and HLJ/HRB/2016/13, formed one potential new clade in the nearly complete genome-based phylogenetic trees. Further analysis revealed that FCoV infection appeared to be significantly correlated with a multi-cat environment (p < 0.01) and with age (p < 0.01). The S gene of the three type I FCoV strains identified in China, BJ/2017/27, BJ/2018/22 and XM/2018/04, exhibited a six nucleotide deletion (C AGCTC ). Our data provide evidence that type I and type II FCoV strains co-circulate in the FIP-affected cats in China. Type I FCoV strains exhibited high prevalence and genetic diversity in both FIP-affected cats and clinically healthy cats, and a multi-cat environment and age (<6 months) were significantly associated with FCoV infection.
猫传染性腹膜炎（Feline infectious peritonitis，FIP）是一种致命的猫科动物传染病，在中国经常有 FIP 的报道。为了追溯中国 I 型和 II 型猫冠状病毒的进化，我们从中国兽医医院收集了 115 份疑似 FIP 猫的腹水样本和 54 份临床健康猫的粪便样本。通过针对 6b 基因的 RT-PCR 检测样本中 FCoV 的存在。结果表明，共有 126 份（74.6%，126/169）样本为 FCoV 阳性：75.7%（87/115）的疑似 FIP 样本为 FCoV 阳性，72.2%（39/54）的临床健康样本为 FCoV 阳性。在 126 份 FCoV 阳性样本中，成功测序了 95 个部分 S 基因。基于部分 S 基因的基因分型表明，I 型 FCoV 和 II 型 FCoV 分别占 95.8%（91/95）和 4.2%（4/95）。基于部分 S 基因的系统发育分析显示，91 株 I 型 FCoV 株具有遗传多样性；4 株 II 型 FCoV 株与来自中国台湾的 II 型 FCoV 株密切相关。3 株 I 型 FCoV 株 HLJ/HRB/2016/10、HLJ/HRB/2016/11 和 HLJ/HRB/2016/13 在近乎完整基因组的系统发育树上形成了一个潜在的新分支。进一步分析表明，FCoV 感染与多猫环境（p<0.01）和年龄（p<0.01）显著相关。在中国鉴定的 3 株 I 型 FCoV 株 BJ/2017/27、BJ/2018/22 和 XM/2018/04 的 S 基因存在 6 个核苷酸缺失（C AGCTC）。我们的数据提供了证据表明，I 型和 II 型 FCoV 株在中国受影响的 FIP 猫中共同循环。I 型 FCoV 株在受影响的 FIP 猫和临床健康猫中均表现出高流行率和遗传多样性，多猫环境和年龄（<6 个月）与 FCoV 感染显著相关。
