Application of Random Amplified Polymorphic DNA Analysis in Discrimination of Salmonella Typhimurium Isolates of India

Realizing the significance of random amplified polymorphic DNA typing in heterogeneity analysis of Salmonella serovars, 22 S. Typhimurium isolates of varied origin were studied for their molecular heterogeneity. Analysis using five primers namely, Primer 1290, NSC II, Primer 5, NSC I and OPB10 classified these isolates into 4, 5, 6, 7 and 8 RAPD types with discriminating powers of 0.6364, 0.671, 0.6927, 0.7879 and 0.88312, respectively. The phylogram constructed with NSC I profile classified isolates based on geographical origin. Primer 1290, NSC II and primer 5 produced some uniform bands in all isolates indicating their binding ability in conserved genomic region. Thus, the present study elucidated a high degree of molecular heterogeneity among Indian isolates of S. Typhimurium along with the presence of some predominant genotypes. It also revealed the importance of RAPD-PCR especially OPB10 primer for heterogeneity analysis of this serovar. NSC I can be used in epidemiological studies for classification of S. Typhimurium isolates based on geographic origin. But, none of the above primers could group isolates based on their host origin, pointing out the potential hazard of interspecies sharing.