北京地区猫杯状病毒的分离鉴定及VP1基因序列分析OACSTPCD

To investigate the prevalence,variation characteristics and pathogenicity of a new epidemic strain of feline calicivirus(FCV),in this study,RT-PCR detection and virus isolation and culture were performed using nasopharyngeal swab samples collected from cats'eyes with suspected FCV infection from several pet hospitals in Beijing from 2016 to April 2022.5 isolates were confirmed.The virus content of 5 isolated FCV strains was determined,the VP1 gene sequence was analyzed,and the pathogenicity of one strain was test-ed.The positive rates of FCV from 2018 to April 2022 were 36.98％,34.30％,41.33％,40.46％and 34.39％,respectively,and the total positive rate was 37.93％.The homologies of VP1 gene and its coding product among 5 FCV strains were 74.1％-85.4％and 83.6％-91.0％,respectively.The homologies of nucle-otide and amino acid between the FCV isolates and vaccine strain 255 were 74.8％-84.5％and 83.7％-91.6％,respectively.The results of pathogenicity test demonstrated that cats infected with BJH13 strain showed typical clinical symptoms of FCV infection,such as depression,loss of appetite,increased body temperature,weight loss,increased eye and nose secretions,red and ulcer tongue.The histopathological re-sults demonstrated that the tongue and lung tissues of FCV-infected cats showed typical pathological char-acteristics of FCV infection.The total results showed that the positive rate of FCV was high.BJH13 strain was more virulent.The VP1 gene sequence of FCV BJH13 strain is significantly different from that of the vaccine strain 255 and F9 used clinically,which maybe a risk of vaccine failure and a great challenge to cur-rent prevention and control of FCV infection.In summary,the results provide scientific basis and new can-didate strains for future vaccine research and development.