Salmonella enterica Serotype typhi in Kuwait and its reduced susceptibility to ciprofloxacin.

Salmonella enterica serotype typhi continues to be an important public health problem in Kuwait. Analysis of the isolates from 163 patients, collected between 1995 and 2003, showed that the majority were from patients from the Indian sub-continent, including 45 from Bangladesh, 38 from India and 30 from Pakistan. Fifty-four of the strains showed multiple antibiotic resistance (MDR). Twenty-five strains were from Kuwaitis, with 15 aged <18 years. Bacteriophage typing of 20 isolates from Kuwaitis revealed that they belonged to 8 different phage types, and that the 3 MDR strains were phage type E1. Random amplified polymorphic DNA typing showed genetic variability amongst isolates from Kuwaiti patients. This method conveniently demonstrated the identity of 4 isolates associated with a small outbreak. 48 isolates from 2002-3 were tested for reduced susceptibility to quinolones. 12 of 18 MDR strains and 7/30 susceptible strains showed reduced susceptibility to ciprofloxacin (minimum inhibitory concentration 0.125-0.5 mg/L). All 12 strains were tested for mutation in the quinolone resistance determining region (QRDR) of the gyr A gene. The mutation ser83 phe was detected in the 10 strains tested. Thus typhoid fever in Kuwait is predominantly associated with those who have traveled from endemic areas to work in Kuwait. The incidence of MDR strains remains at about 30%. Reduced susceptibility to ciprofloxacin in MDR S. typhi has increased from (11%) in 1995-1996 to (67%) in 2002-2003 and from (0%) to (23%) in susceptible strains. Mutation of the gyrA gene is the mechanism most often responsible.