Doripenem, Ertapenem, and Meropenem Sensitivity in Salmonella Typhi: A Cross-Sectional Study From Pakistan

Background Salmonella Typhi (S. Typhi) is increasingly resistant to multiple antibiotics, posing a challenge in treatment, particularly in multidrug-resistant (MDR) cases. Carbapenems, including doripenem, ertapenem, and meropenem, have been considered last-resort options. This study evaluates the effectiveness of these carbapenems against S. Typhi isolates in a clinical setting in Peshawar, Pakistan. Objective To assess the effectiveness of the carbapenem antibiotics, doripenem, ertapenem, and meropenem, against S. Typhi. Methods This study collected data from blood cultures of patients diagnosed with S. Typhi infections at the Hayatabad Medical Complex in Peshawar, Pakistan for two years: from January 1, 2022, to December 31, 2023. Sensitivity testing was performed using the disk diffusion method in accordance with Clinical and Laboratory Standards Institute (CLSI) guidelines. The analysis examined the sensitivity rates of the three antibiotics and compared their effectiveness. Results A total of 626 S. Typhi isolates were tested. Only 11.98% of the isolates were sensitive to doripenem, while 88.02% were resistant to it. In contrast, 35.5% of the isolates responded to ertapenem, with 64.5% being resistant. Meropenem showed the highest efficacy, with 42.7% of the isolates demonstrating sensitivity. These findings highlight the growing challenge of managing multidrug-resistant (MDR) S. Typhi infections, especially in regions where resistance to carbapenems is becoming prevalent. Conclusion Meropenem proved to be more effective against S. Typhi compared to doripenem and ertapenem. The study emphasizes the need for ongoing monitoring of resistance patterns and the exploration of alternative or combination treatment options. These findings have immediate clinical implications for empiric therapy choices and highlight the urgent need for antibiotic stewardship programs in endemic regions.