Drug Resistance Patterns of Typhoidal and Non-typhoidal Salmonella Species in Hamadan

ABSTRACT The epidemiological studies indicate that the incidence of salmonellosis is increasing throughout the world. The uncontroled and unappropriate usage of antibiotics has been caused multi - drug resistance in these organisms, in recent years. In a cross-sectional descriptive study, 204 strains of typhoidal salmonella (T.S) and 114 strains of non-typhoidal salmonella (N.T.S) were examined to determine drug resistance. The strains were collected from patients who referred to clinical centers in Hamadan during 1994 to 1997. They were serotyped and then tested for their antibiotic resistance patterns, using Kirby-Bauer method for 8 antibiotics. The salmonella isolated were as follows: "S.typhi, S. paratyphi A, B, C, S.murium, enteritidis, S. choleraesuis, S. agona, S. arizona, S. infantis, S. havana, S. lexington and S. virchow." A proportion of strains (> 60%) were resistance to Carbenicillin and ampicillin. Resistance to Ciprofloxacin and Nalidixic acid was very low (< 15%). S.typhimurium (100%), S. typhi (95.7%), parathyphi B (89.2%) and enteitidis (60%) showed multi-drug resistance (MDR). We suggest that the use of some newer antibiotics such as new fluoroquinolones, ceftazidime, imipenem and aztreonam as effective therapy againts salmonella species.