Antibiotic Resistance Profile of Salmonella Typhi Clinical Isolates in Urban Dhaka

Abstract Background: Typhoid fever, caused by Salmonella enterica serovar Typhi, remains a significant public health concern in many low- and middle-income countries. Bangladesh is recognized as a high-burden region, particularly in urban centers such as Dhaka, where enteric fever continues to contribute substantially to morbidity, mortality, and economic strain. Objectives: To determine the prevalence of Salmonella Typhi among bloodstream infections and to assess antimicrobial resistance patterns in febrile patients in Dhaka, Bangladesh. Methods: This retrospective cross-sectional study was conducted at a multispecialty tertiary care center in Dhaka from July 2022 to January 2023. Blood cultures obtained from febrile patients were processed for identification of S. Typhi. Antimicrobial susceptibility testing was performed using standard laboratory protocols, with particular focus on multidrug resistance and reduced fluoroquinolone susceptibility. Results: A total of 60 culture-positive S. Typhi isolates were identified. Males were slightly more affected (male-to-female ratio 8:7). Fever was present in all patients, while vomiting and diarrhea were each reported in 18% of cases. Hepatomegaly and splenomegaly were observed in 18% and 36% of patients, respectively. Relative leukopenia and absolute leukopenia in 33%, while leukocytosis was noted in 15%. Elevated ALT levels were detected in 70% of cases, and 23% showed increased bilirubin. All isolates were fully sensitive to ceftriaxone. Resistance to amoxicillin, chloramphenicol, and trimethoprim-sulfamethoxazole ranged from 13% to 20%. High resistance was observed to nalidixic acid (97%), ciprofloxacin (74%), and azithromycin (85%). Conclusion: Enteric fever remains an important clinical and public health issue in Bangladesh, further complicated by high antimicrobial resistance levels.