Survival of salmonella typhi in some cold drinks of Yangon

ABSTRACT

The study was carried out to obtain information about the survival of S. typhi in drinking waters and some cold drinks if it is contaminated. It was carried out from August 1997 to July 1998 in Bacteriology Research Division, Department of Medical Research. The samples were collected from South Okkalapa Township, Yangon. A total of 152 samples were studied. pH was measured in all samples by pH meter. One hundred ml or water and cold drink sample was contaminated with S. typhi to a final concentration of 10 to the power 5 colony forming unit per mI. Viable counts of S. typhi were determined by drop plate method as once daily until the viable counts were negative. S. typhi did riot survive in tested cold drinks, which have pH between 1.35 and 2.48. The contaminant survived up to 10,32 and 38 days in some cold drinks (pH between 2.52 and 3.55), sugar cane juice (pH 5.25), Jelly juice (pH 5.94) and drinking waters (pH between 6.6 and 7.1) respectively at 4 degree centigrade. In this study it was found that S. typhi survives in acidic cold drinks and also survives in cold drinking waters for a long period.