THE LAST LINE OF DEFENSE: EVALUATING THE EFFICACY OF MEROPENEM AND FOSFOMYCIN AGAINST MULTIDRUG-RESISTANT SALMONELLA TYPHI

Abstract

There is an urgent need to assess and repurpose current medications due to the concerning increase in antimicrobial resistance, especially in multidrug-resistant (MDR) Salmonella Typhi. In many endemic areas, traditional first-line medications have become ineffective, which has led to research into carbapenems like meropenem and older medications like fosfomycin as possible last-resort therapies.A total of 200 people, between the ages of 20 and 40 participated in a six-month cross-sectional study at Ziauddin University Hospital in Karachi. The modified Kirby-Bauer disk diffusion method was used to analyze blood cultures from patients suspected of having typhoid fever for antibiotic susceptibility. Two therapy groups were examined: Group B received 15 µg of fosfomycin, and Group A received 10 µg of Meropenem. The Chi-square test was used to compare susceptibility patterns by gender and age (p < 0.05 as significant).

In contrast to fosfomycin (50% and 36% in the corresponding age groups; p = 0.03), meropenem showed greater overall susceptibility (72% in 20–30 years, 60% in 30–40 years; p = 0.04). For both antibiotics, a gender analysis showed no statistically significant variations in medication efficacy. Fosfomycin demonstrated limited age-dependent efficacy with considerable resistance, particularly in elderly patients, but meropenem maintained moderate effectiveness across demographics.When it comes to treating MDR Salmonella Typhi, Meropenem works better than Fosfomycin, particularly in younger adults. Age is a more important factor in determining susceptibility than gender.