Raut S D, Rajak K K, Kumar R, Singh V K, Saxena A, Chaudhary D, Muthuchelvan D, Pandey A B
Classical Swine Fever Virus Laboratory, Division of Virology, Indian Veterinary Research Institute, Campus Mukteswar, Nainital, 263 138 Uttarakhand India.
Department of Microbiology, DUVASU, Mathura, Uttar Pradesh India.
Virusdisease. 2015 Jun;26(1-2):70-6. doi: 10.1007/s13337-015-0253-0. Epub 2015 May 23.
Classical swine fever virus (CSFV), the causative agent of classical swine fever, belongs to the family Flaviviridae and genus Pestivirus. Some pestiviruses exhibit cytopathic effect in cell culture but exact phenomenon is unknown. Over expression of NS2-3 gene, presence of defective interfering particle and exaltation of Newcastle disease virus (END) phenomenon could be the reasons of cytopathogenicity. In the present study, a CSFV isolate exhibiting cytopathic effect (CPE) in Madin-Darby Canine Kidney (MDCK) cell line was characterized. To characterize cytopathogenicity of such isolate, END test was carried out. Interference of Newcastle disease virus (NDV) in MDCK adapted CSFV was confirmed by RT-PCR and virus neutralization test. Absence of CPE and NDV specific nucleic acid after neutralization confirmed the induction of CPE by NDV. Further, identity of the CSFV isolate in MDCK cell line by immunoperoxidase test, immunoblotting and RT-PCR post NDV neutralization established the virus replication without CPE (non-cytopathic isolate). Findings suggest that, there could be a chance of mixed infection of both CSFV and NDV in the piglet from which the sample was collected for virus isolation.
经典猪瘟病毒（CSFV）是经典猪瘟的病原体，属于黄病毒科瘟病毒属。一些瘟病毒在细胞培养中表现出细胞病变效应，但确切现象尚不清楚。NS2 - 3基因的过度表达、缺陷干扰颗粒的存在以及新城疫病毒（END）现象的增强可能是细胞病变性的原因。在本研究中，对一株在犬肾传代细胞（MDCK）细胞系中表现出细胞病变效应（CPE）的CSFV分离株进行了鉴定。为了鉴定该分离株的细胞病变性，进行了END试验。通过逆转录 - 聚合酶链反应（RT - PCR）和病毒中和试验证实了新城疫病毒（NDV）对适应MDCK的CSFV的干扰。中和后CPE和NDV特异性核酸的缺失证实了NDV诱导了CPE。此外，通过免疫过氧化物酶试验、免疫印迹和NDV中和后的RT - PCR鉴定了MDCK细胞系中的CSFV分离株，确定该病毒在无CPE的情况下进行复制（非细胞病变分离株）。研究结果表明，从采集用于病毒分离的仔猪样本中，可能存在CSFV和NDV混合感染的情况。
