APPLICATION OF COMBINATION, IMMUNOMAGNETIC SEPARATION PLUS MULTIPLEX PCR FOR THE DETECTION AND IDENTIFICATION OF SALMONELLA ENTERICA SUBSPECIES ENTERICA SEROVAR TYPHIMURIUM IN BOVINE DIARRHOEIC FECAL SAMPLES

A total of 400 bovine diarrhoeic fecal specimens were obtained and conventional microbial culture, immunomagnetic separation and multiplex PCR were simultaneously carried out on samples. For detection of Salmonella at genus level, inv-A universal primer was selected. In order to identifiing of Salmonella typhimurium, specific primers of Rfbj, Fljb and Flic related to gene sequence of O4, H2:1,2 and H1: i were used, respectively. Results showed, 33(8.5%)were culture positive for Salmonella serotypes. However, Salmonella typhimurium with(66.7%), Salmonella dublin(9.1%), Salmonella virchow(6.1%), Salmonella gloucester(6.1%), Salmonella enteritidis(3%), Salmonella georgia(3%), Salmonella augustenborg(3%)and Salmonella lindenburg(3%), were the most common isolated serovars, respectively. In the IMS+Multiplex PCR four amplified products(663,526,284 and 183 bp) were found in all specimens which had typhimurium serovar(1,4,5,12:i:1,2)from rfbj,fljb,inv-A and flic genes, respectively. Results showed that detection and identification of Salmonella typhimurium using specific primers of O4, H2:1,2 and H1: i antigens can be useful.