Shigellosis, an intestinal infection caused by Shigella species, is manifested by bloody diarrhea. Due to the surge in multidrug-resistant (MDR) Shigella species, the control of shigellosis has been a big challenge. This study aims to determine the prevalence and assess the antibiotic susceptibility pattern of Shigella species. During our study period of five months from April 2014 to August 2014 at Sukraraj Tropical and Infectious Disease Hospital, Teku, Kathmandu, a total of 653 stool samples were collected from the patients suspected of acute gastroenteritis. The standard microbiological procedure was followed for the isolation and identification of Shigella species. Assessment of antibiotic susceptibility pattern of the Shigella species was done by Kirby-Bauer disk diffusion method following CLSI guidelines. The study found 25(3.82%) cases were Shigella positive. Among them, 18(72%) were S. flexneri, 6(24%) were S. dysenteriae, and 1(4%) was S. sonnei. The patients in the age group 16-45 years were highly susceptible to infection as the higher proportion 16(64%) of Shigella species were isolated from this age group (p> 0.05). Shigella species were found to be highly susceptible to Cefotaxime (100%), a third-generation cephalosporin. Nalidixic acid, on the other hand, was the least effective antibiotic as 20(80%) of the Shigella isolates were resistant, followed by Ampicillin 18(72%), Cotrimoxazole 13(52%), and Ciprofloxacin 9(36%). A higher proportion of [10(40%)] of our study isolates were MDR. Our results show that Nalidixic acid, Ampicillin, Cotrimoxazole, Ciprofloxacin, and Ofloxacin cannot be used as empirical therapy for the treatment of Shigella infection as Shigella species were highly resistant to these antibiotics. So, for the MDR Shigella infection, we suggest third-generation cephalosporin as an option.

Objectives: The study aimed to assess the antibiotic susceptibility profile of Salmonella spp isolated from patients suspected of enteric fever. Methods: This cross-sectional prospective study was carried out from April to June, 2014among 484 patients clinically suspected of enteric fever visiting Bir Hospital, Kathmandu, Nepal. Blood sample collected from each patient was processed for culture in bile broth. Identification of Salmonella spp was done by conventional microbiological techniques including colony characteristics, Gram's staining and biochemical tests. Antibiotic susceptibility testing of identified isolates was done by Kirby-Bauer disk diffusion method following the 2014 CLS I guideline. Results: Out of 484 blood samples, 36 (7.43%) cases showed the growth of Salmonella spp; of which 27 (75%) were Salmonella enterica serovar Typhi (ST) and 9 (25%) were Salmonella enterica Paratyphi A (SPA). Among the Salmonella isolates, 5.55% were multidrug resistant and 41.66% were fluoroquinolone resistant. More than 80% of isolates were sensitive to chloramphenicol, amoxicillin, and cotrimoxazole whereas 58%, 50% and 6% of isolates were sensitive to fluoroquinolone antibiotics i.e. ciprofloxacin, ofloxacin and nalidixic acid respectively. All the isolates were susceptible to ceftazidime. All SPA and 89% of ST were sensitive to azithromycin. Conclusion: Higher percentage of susceptible isolates to chloramphenicol, cotrimoxazole, and amoxicillin suggests the reconsideration of these antibiotics for the treatment of enteric fever. Azithromycin can be considered as drug of choice for the treatment of enteric fever.