Antibiotic susceptibility patterns of Salmonella and Shigella isolates in Harar, Eastern Ethiopia

Antimicrobial resistance of Salmonella and Shigella are emerging global challenges. There are no studies conducted on the antimicrobial susceptibility patterns of Salmonellaand Shigella in eastern Ethiopia. This study aims to investigate antimicrobial susceptibility patterns of these microbes. A total of 244 diarrheic stool specimens were collected and cultured for screening of microbes using standard methods. Afterwards, the isolates were confirmed as Salmonella or Shigella by using a battery of biochemical reactions. Antibiotic susceptibility testing was performed using six selected drugs (ampicillin, amoxicillin, tetracycline, chloramphenicol, norfloxacin, and gentamicin). 28 (11.5%) Salmonella and 17 (6.7%) Shigella organisms were isolated from 244 stool samples. Sensitivity of the Salmonella isolates were 0.0% to ampicillin; 0.0% to amoxicillin; 14.2% to tetracycline; 28.6% to chloramphenicol; 89.3% to norfloxacin; and 92.8% to gentamicin. Shigella had sensitivities of 0.0% to ampicillin; 0.0% to amoxicillin; 11.8% to tetracycline; 41.2% to chloramphenicol; 88.2% to norfloxacin; and 94.1% to gentamicin. A high level of antimicrobial resistance was detected in both Salmonella andShigella isolates. The organisms developed complete resistance to ampicillin and amoxicillin. The results of the study demonstrated that gentamicin and norfloxacin are drugs of choice for treating diarrhea caused by these microbes.