History and Objectives: Inappropriate antibiotic treatment can lead to resistance with various incidences in different populations and is one of the major problems facing treatment of diarrhea. This study was carried out to determine the incidence of antibiotic resistance in referrals of reference laboratory of Kashan University of Medical Sciences from 2000 to 2001.

Materials and Methods: The descriptive strategy of this study was conducted on 1800 patients with acute diarrhea. Fecal specimens were collected and transferred to specific culture medium. Antibiotic discs of ciprofloxacin, ceftizoxime, chloramphenicol, co-trimoxazole, nalidixic acid, doxycyclin, tetracycline, cephazolin, furazolidone, cephalotin and amikacin were used for determination of sensitivity of Shigella, Salmonella, Vibrio cholera.

Results: Out of 1800 fecal specimens, there was a growth rate of 11.9% (215 cases), that is 58.1% (125 cases), 30.7% (66 cases) and 11.2% (24 cases) for Shigella, Salmonella and Vibrio cholera respectively. For Shigella, the sensitivity to ciprofloxacin, ceftizoxime, chloramphenicol, nalidixic acid, co-trimoxazole, doxycyclin, cephazolin, furazolidone, ampicillin and cephalotin was 99%, 97%, 84%, 74%, 58%, 54%, 47%, 35%, 23% and 22% respectively. For Salmonella, the sensitivity to ciprofloxacin, chloramphenicol, ceftizoxime, co-trimoxazole, cephazolin and furazolidone was 100%, 96%, 78%, 20% and 12% respectively. For Vibrio cholera, the sensitivity to ciprofloxacin, doxycyclin, tetracycline, ceftizoxime, co-trimoxazole, nalidixic acid, furazolidone, cephazolin, cephalotin and ampicillin was 100%, 100%, 100%, 95.8%, 87.5%, 83.3%, 79.2%, 79.2%, 75% and 62.5% respectively.

Conclusion and Recommendations: Considering the incremental trend for antibiotic resistance for Shigella, Salmonella and Vibrio cholera, it is strongly recommended to avoid inappropriate and unnecessary use of antibiotics in patients with diarrhea.