为探究华中地区犬副流感病毒(CPIV)的流行及遗传进化情况,利用RT-PCR方法对华中地区2020年9月—2022年1月收集的418份病料样品进行了CPIV检测,并利用生物信息学软件对分离的CPIV毒株的F、HN基因进行同源性、氨基酸位点分析及系统发育分析.结果显示:CPIV阳性率为15.8％,扩增获得9株CPIV的F、HN基因的序列,并成功分离培养9株CPIV毒株;同时,将分离株的F、HN基因与19株副流感病毒参考毒株进行序列比对分析,结果表明,F基因核苷酸同源性为95.1％～100％,氨基酸同源性为94.6％～99.8％,HN基因核苷酸同源性为95.9％～99.9％,氨基酸同源性为95.8％～99.6％;CPIV的F及HN基因与参考毒株相比均有部分氨基酸发生了突变;系统发育分析结果显示,本研究获得的8株分离株与美国株CPI-和CPI+处于同一分支上,亲缘关系较近,另一株分离株CS-324与中国株HeN0718和韩国株D277位于同一分支上.本研究丰富了华中地区CPIV的流行病学调查资料,并为该病的综合防控提供了理论依据.

为了解华中地区犬源CDV所属谱系、流行及遗传变异情况,本试验通过RT-PCR方法对华中地区2020年9月～2022年1月收集的418份犬源病料进行了检测,其中83份样品为CDV阳性,阳性率为19.9％.将阳性样品接种Vero细胞,并通过间接免疫荧光方法鉴定,成功获得13株CDV分离株.对13株CDV分离株H基因进行测序,并与32株CDV参考毒株进行同源性分析、遗传进化分析以及H蛋白潜在N糖基化位点预测分析.结果表明,分离到的13株野毒株与参考毒株相比,核苷酸同源性为87.1％～99.8％,氨基酸同源性为82.2％～100％;其中8株分离株在基因型上归属于Asia-1型,5株归属于America-1型;H基因抗原性预测分析表明,分离到的13株野毒株具有6～9个潜在的N糖基化位点.本研究为本土流行性CDV毒株的研究奠定了基础.

为了解华中地区犬细小病毒2型(CPV-2)的流行趋势以及变异情况,本研究于2020年9月至2022年1月间采集华中地区的418份疑似感染犬细小病毒的粪便样品,通过PCR方法检测,利用F81细胞进行病毒分离、间接免疫荧光试验,并对分离病毒的VP2基因进行氨基酸序列及其同源性和遗传进化分析.结果显示,358份病料检测出CPV-2,阳性率为85.65％.病料接种F81细胞后,有23份阳性样品出现明显细胞病变,间接免疫荧光试验观察到明显荧光.VP2基因序列分析结果表明,分离毒株中有New-CPV-2a型12株、New-CPV-2b型5株、CPV-2c型6株.核苷酸同源性为97.9％～99.8％,氨基酸同源性为95.9％～100.0％.遗传进化分析结果显示,分离毒株与国内分离株、伊朗、巴西分离株亲缘关系较近,与意大利、日本、阿根廷分离株亲缘关系较远.本研究为华中地区犬细小病毒防控及研制高效疫苗奠定了基础.

Feline calicivirus (FCV) is an important feline pathogen mainly causing upper respiratory tract disease, conjunctivitis, and stomatitis, and it is classified into genotype I and genotype II. To investigate the prevalence and molecular characteristics of FCV, this study collected 337 cat swab samples from animal hospitals in different regions of China from 2019 to 2021. The positive detection rate of FCV was 29.9% (101/337) by RT-PCR. Statistical analysis showed that FCV prevalence was significantly associated with living environment ( p = 0.0004), age ( p = 0.031) and clinical symptoms ( p = 0.00), but not with sex ( p = 0.092) and breed ( p = 0.171). The 26 strains of FCV were isolated using F81 cells. Phylogenetic analysis showed that 10 isolates belonged to genotype I, and 16 isolates belonged to genotype II. These 26 isolates were highly genetically diverse, of which HB7 isolate had three same virulence-related amino acid loci with VSD strains. Potential loci distinguishing different genotypes were identified from 26 isolates, suggesting the genetic relationship between different genotypes. In addition, selection pressure analysis based on capsid protein of 26 isolates revealed that the protein is under diversifying selection. This study reveals the genetic diversity of FCV and provides a reference for the screening of vaccine candidate strains and the development of vaccines with better cross-protection effects.