Antimicrobial susceptibility of Salmonella typhi and non-typhi in a hospital in eastern Saudi Arabia

The objective of this study was to determine the antimicrobial susceptibility of Salmonella typhi and non-typhi at Saudi Aramco Medical Services Organization (SAMSO). We retrospectively identified isolates of S. typhi and non-typhi from January 1996 to December 2003. Antimicrobial sensitivity and clinical data were collected and analyzed. A total of 266 distinct isolates of S. typhi and non- typhi were available for analysis. Of the total isolates, 21.4% (n= 57) were S. typhi and 78.6% (n= 209) were Salmonella non-typhi and their most common serogroups were D (20.3%), C (19.5%) and B (15.8%). None of Salmonella spp. was resistant to ceftriaxone or ciprofloxacin. The susceptibility of S. typhi and non- typhi to trimethoprim-sulfamethoxazole (TMP-SMX) was 89% and 84% (P = 0.3) and to tetracycline was 81.3% and 56.6%, respectively (P <0.001). Ampicillin susceptibility was detected in 89% and 77% of S. typhi and non-typhi, respectively (P = 0.038). Multidrug resistance was present in 20% of S. typhi and 18.9% of Salmonella nontyphi. There was no difference in the susceptibility pattern of salmonella between Saudi and non-Saudi patients except for gentamicin susceptibility (97.3% vs. 65.9%, P < 0.001).