TREND ANALYSIS OF RESISTANCE TO FIRST-LINE ANTIBIOTICS IN SALMONELLA BLOOD ISOLATES

Abstract

Background: Salmonella Typhi causes significant morbidity and mortality worldwide, particularly in low- and middle-income countries (LMICs), where resistance to first-line antibiotics, including multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains, challenges treatment. This study evaluated resistance trends in Salmonella blood isolates from a regional cohort.

Objective: To assess the prevalence and patterns of antibiotic resistance among Salmonella Typhi blood isolates to first-line antibiotics in a tertiary care hospital in Peshawar, Pakistan, and identify trends in MDR and XDR strains to inform local treatment protocols and antimicrobial stewardship.

Material and Methods: This retrospective cross-sectional study analyzed 626 Salmonella blood isolates collected from January 2022 to December 2023 at Hayatabad Medical Complex, Peshawar, after getting ethical approval vide  No.222, dated13.12.2023 Antibiotic susceptibility was tested using CLSI guidelines, targeting ampicillin, ciprofloxacin, trimethoprim-sulfamethoxazole (TMP-SMX), and third-generation cephalosporins. Data were analyzed using SPSS Version 26.

Results: Resistance rates were 70% for ampicillin, 65% for TMP-SMX, 30% for ciprofloxacin, and 20% for third-generation cephalosporin’s, with a significant increase in ceftriaxone resistance from 15.2% in 2022 to 24.8% in 2023 (p=0.002). MDR and XDR strains accounted for 37.9% and 8.5% of isolates, respectively, necessitating updated treatment strategies.

Conclusion: The rising resistance to first-line antibiotics, especially in MDR and XDR Salmonella strains, requires urgent attention. Enhanced surveillance, vaccination, improved sanitation, and antibiotic stewardship are critical to address this growing threat.