RECENT KNOWLEDGE IN THE ENTERAL CORONAVIR USES IN PIG - REVIEW ARTICLE

The article, based on the latest literary data, briefly summarizes the most important aspects of the porcine coronaviruses commonly found in pig herds throughout the world, namely transmissible gastroenteritis virus (TGEV), porcine respiratory coronavirus (PRCV) and porcine epide mic diarrhoea virus (PEDV). It deals with the results of the molecular biological methods applied in corona virology, such as the descriptio n of two cellular TGEV receptor proteins, the localization of the puta tive receptor binding sites on the spike protein of the virion. Accord ing to the latest findings published in the literature there are certa in characteristic differences in the genome of TGEV and PRCV. The most important one of these, is the deletion localized on the spike gene o f the PRCV. This deletion seems to be responsible for the different ti ssue tropism of the two viruses, and the paper points out the practica l importance of this finding. According to the data gethered on passiv e and active immunization experiments of pigs, the missing sequences c ode for epitopes crucial in the induction of protective immunity in pi glets. The difference of the genomes can be utilized in the diagnostic s, to differentiate PRCV and TGEV infections on a serological basis, o r by the currently developed nucleic acid analysing techniques. The au thor mentions the genetic relationships of the three porcine coronavir uses and coronaviruses of other species according to a recent phylogen etic analysis. Based on this analysis there is a marked distance betwe en the closely related TGEV/PRCV and the PEDV. Compares some of the ch aracteristics of the epidemiology and pathogenesis of TGE and FED. In addition it gives some points of reference of the new differential dia gnostic methods of the field, such as the use of monoclonal antibodies or the development of polymerase chain reaction assays and the applic ation of non-radioactive probes in in situ hybridisation tests.