Disc Diffusion Technique.

The aim of the study was to evaluate the occurrence and diversity of multi drug resistant salmonella enteric serovar typhi existing in and around Chennai, India. Drug resistivity of isolates was carried out from the sample which was collected from the patients those are suspected to suffer from typhoid fever. A total of 2423 samples have been collected from various hospitals and organizations in and around Chennai. As soon as the sample collection all the isolates were cultured using various nutrient media to evaluate the cultural characteristics of the isolates followed by preliminary tests and biochemical tests using standard identification procedure to confirm the isolates for salmonella enterica serovar typhi. The total of 105 out of 2423 clinical isolates was confirmed for salmonella enterica serovar typhi and these isolates were further undergone to various procedures like Bio typing, Phage typing and serological tests (Agglutination) using standard identification procedure for phenotypic characterization. For antibiotic resistivity pattern an in-vitro test procedure using Kirby-Bauer method was conducted for the identified isolates using various antibiotics with different strengths. The specimens were collected from various age groups lying between