Changing Sensitivity Pattern of Salmonella Typhi in Calicut
Calicut Medical Journal 2004;2(1):e2
A retrospective study of the sensitivity pattern of S.typhi isolated between 1995 and 2003 was done. The strains were tested for susceptibility to Ampicillin, Cotrimoxazole, Chloramphenicol, Furoxone, Ciprofloxacin, Ceftriaxone and Nalidixic acid. Multi drug resistant S.typhi (MDR) was endemic in Calicut from 1989 (68.7%) but since 2002 incidence of MDR isolates decreased substantially (21,05%). 120 (90.22%) S.typhi strains isolated between 1999 and 2003 were resistant to Nalidixic acid, showing treatment failure with Ciprofloxacin. MIC to Ciprofloxacin for 42 strains showed that, 11 Nalidixic acid sensitive S.typhi (NASST) had MIC of 0.015 mg / ml and the rest 31 Nalidixic acid resistant S.typhi (NARST) had MICs ranging 0.25 – 1 mg / ml, showing low-level resistance to Ciprofloxacin. These patients were unresponsive to Ciprofloxacin in the usual therapeutic dose.
Key words: S.typhi, multidrug resistance, Ciprofloxacin resistance
