Emerging Trends of Multidrug-Resistant (MDR) and Extensively Drug-Resistant (XDR) Salmonella Typhi in a Tertiary Care Hospital of Lahore, Pakistan

Salmonella Typhi is a Gram-negative pathogen that causes typhoid fever in humans. The use of antibiotics to treat typhoid has considerably mitigated its fatality risk, but rising multidrug-resistant (MDR) and extensively drug-resistant (XDR) resistance in Pakistan threatens effective treatment. This study determined the prevalence of MDR and XDR S. Typhi at a local hospital in Lahore. Blood samples (n = 3000) were obtained and processed for bacterial identification. Antibiotic susceptibility test was performed using VITEK(R) 2 Compound 30 System. Statistical data analysis was performed using a Mann-Whitney U and Kruskal-Wallis H test, respectively. The results revealed 600 positive cultures, of which the majority were found to be XDR S. Typhi (46.1%) and MDR S. Typhi (24.5%) strains. The disease burden of resistant Salmonella strains was greater in males (60.67%) than females (39.33%), with the most affected age group being 0-10 years old (70.4 %). In both the outpatient department (OPD) and general ward, the prevalence of XDR S. Typhi cases was found to be alarmingly high (48.24%), followed by MDR S. Typhi (25.04 %). The results of the statistical analysis demonstrated that the incidence of resistance in MDR and XDR S. Typhi strains was not affected by the age as well as the gender of patients (p > 0.05). The occurrence of resistant strains against four tested antibiotics (azithromycin, ciprofloxacin, imipenem, and meropenem) was found to be similar in different wards and among hospitalized and OPD patients (p > 0.05). Maximum resistance was observed against chloramphenicol and ampicillin in the OPD and pediatric ward. Piperacillin/Tazobactam was observed to be the most effective antibiotic, followed by co-amoxiclav (p < 0.001). This study is effective in validating the existence of MDR and XDR S. Typhi in Lahore, where stringent methods should be applied for controlling its spread.