Susceptibility Pattern of Salmonella Typhi and Paratyphi A in Blood Cultures in a Tertiary Care Public Hospital

Abstract

Objective: To identify recent susceptibility patterns of Salmonella enterica subspecies enterica serovar Typhi (S. Typhi) and Paratyphi A in a government hospital in Taxila Cantt and to determine the frequency of Multi-Drug Resistant (MDR) and Extensively Drug-Resistant (XDR) S. Typhi. Study Design:  Cross-sectional study. Place and Duration of Study: Pathology Department, HIT Hospital, Taxila Cantt, Pakistan, from Jan 24 to Jan 25. Methodology: Samples of blood cultures from patients suspected of having enteric fever were received in the microbiology section, HIT Laboratory, Taxila Cantt. Isolates of Salmonella Typhi and Paratyphi A from positive blood cultures were included in the study. Antibiotic susceptibility was tested based on CLSI guidelines (2024). Descriptive statistics were shown as Mean ±SD. Results: In this study, out of the 64 positive blood cultures for Typhoidal Salmonella from patients (median age 20), 95.3% were Salmonella Typhi (61) and 4.7% were Salmonella Paratyphi A (03). In 71.9% of cases, CRP was positive. After using appropriate antimicrobials, fever took around five days to settle. Out of the total Salmonella isolated from blood culture, including both species of Salmonella Typhi and Paratyphi A, Azithromycin and Meropenem showed 100% susceptibility, as compared to first-line antibiotics with % resistance of 92, 90.6, and 87.5 for Ampicillin, co-trimoxazole, and chloramphenicol, respectively. Ciprofloxacin and Ceftriaxone demonstrated substantial resistance rates of 97% and 76.6%, respectively.   Conclusions: This study showed significant antimicrobial resistance to multiple antibiotics in both Salmonella Typhi and Paratyphi A isolates, with an alarmingly high number of MDR and XDR strains of