MULTIDRUG RESISTANT SALMONELLA-TYPHI IN CALICUT, SOUTH-INDIA

Eighty S. typhi strains isolated during the period of one year (July 1 989 to June 1990) were tested for susceptibility to chloramphenicol, a mpicillin, cotrimoxazole, gentamicin, kanamycin, cefazolin, furazolido ne and ciprofloxacin. Determination of minimum inhibitory concentratio n (MIC) by tube dilution method showed that the multiply resistant S. typhi strains were resistant to chloramphenicol and ampicillin up to a concentration of 1000-mu-g/ml. MIC of sulphamethoxazole was found to be 800-mu-g/ml and trimethoprim 160-mu-g/ml. The presence of R plasmid was demonstrated by resistance transfer experiments using Esch. coli K12 (F-Lac + Nal-) as the recipient. On phage typing, most of the mult iresistant S. typhi isolates were found to belong to phage type E1.