Association of Demographic and Clinical Determinants with Antibiotic Resistance Patterns in Salmonella enterica Serovar Typhi: A Cross-Sectional Study
DOI:
https://doi.org/10.52206/jsmc.2026.16.2.1447Abstract
Background: Salmonella enterica serovar Typhi remains a major cause of enteric fever in low- and middle-income countries, particularly Pakistan, where antimicrobial resistance (AMR) is rapidly escalating. The emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains has significantly compromised treatment efficacy, necessitating continuous surveillance of resistance patterns and associated risk factors.
Objective: To determine the antibiotic resistance patterns of Salmonella enterica serovar Typhi and evaluate their association with demographic and clinical characteristics among patients in a tertiary care setting.
Methodology: This cross-sectional study was conducted at a tertiary care hospital in Karachi from January to June 2021. A total of 200 blood culture-confirmed Salmonella enterica serovar Typhi isolates were analyzed. Antimicrobial susceptibility testing was performed using the Kirby–Bauer disc diffusion method on Mueller–Hinton agar following CLSI M100 2023 guidelines. MDR and XDR classifications were defined according to established criteria.
Results: Among 200 patients, the majority were aged 10–19 years (34%) and 55.5% were males. Prior antibiotic use was reported in 37.5% of cases, while 34% required hospitalization. High resistance rates were observed for ampicillin (64%), co-trimoxazole (63.5%), and chloramphenicol (61.5%), with notable resistance to ciprofloxacin (53%). Younger age (<20 years), urban residence (p = 0.027), prior antibiotic use (p = 0.009), and comorbidities (p = 0.032) were significantly associated with resistance, whereas gender and hospitalization were not.
Conclusion: Antibiotic resistance in Salmonella enterica serovar Typhi is significantly influenced by demographic and clinical factors, particularly younger age, urban residence, prior antimicrobial exposure, and comorbid conditions. Strengthening antimicrobial stewardship, expanding Typhoid Conjugate Vaccine (TCV) coverage, and implementing targeted public health interventions are essential to mitigate resistance in high-risk populations.
Keywords: Antimicrobial resistance, Pakistan, Salmonella enterica serovar Typhi, Typhoid fever, multidrug resistance.
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