Introduction: Shigella infections caused by gram-negative bacilli intestinal has created problems in the developed and developing countries.  Indiscriminate use of antibiotics, regardless of the resistance has caused the emergence of resistant strains. The aim of this study was to investigate the prevalence of sulfonamide resistance genes and class 1 integron in Shigella sonnei strains isolated from patients with diarrhea and determination of antibiotic susceptibility of the isolates.
 
Materials &methods:  A total of 60 isolates were collected out of the Shigella Sonnei bacteria isolated from fecal infection at Kerman hospitals and cultured in specific media and then confirmed by biochemical tests. Sulfonamide resistance genes were studied including sulI and sulII and intI1 by Multiplex-PCR methods. Antibiotic susceptibility was determined to 8 isolates to different antibiotics by disk diffusion method.
 
Findings: As a result, M-PCR was found in one-sample SulI genes and gene sulII genes in 32 samples, but intI1 gene was not detected in any of the strains. The results demonstrated the greatest resistance to antibiotic of Nalidixic acid (96.6%) and the highest sensitivity to ciprofloxacin(92.1%), respectively.
 
Conclusion & discussion: Our study proved the resistance of Shigella sonnei strains to antibiotics. Therefore, it is essential to take deep medical care and conduct an appropriate use of antibiotics to prevent the spread of resistant strains. In addition, it was found that the gene sulII was the most frequent resistance gene to sulfonamide.