Antibiotic Resistance: Targeting Extensively Drug Resistant (XDR) Salmonella Typhi

Abstract

Typhoid fever is one of the most life-threatening bacterial infections and is caused by the gram-negative rod-shaped bacteria Salmonella enterica serovar Typhi (S. Typhi). It is a significant worldwide health hazard and an important cause of fatalities in growing nations. Salmonella is spread through consuming contaminated food and water. Once the infection occurs, its symptoms, like high fever, abdominal pain, rash, constipation, weakness, headache and poor appetite etc. Particularly seen in Pakistan is the alarming rise in the burden of typhoid due to the multi-drug-resistant (MDR) and extensive drug-resistant (XDR) Strains. In Pakistan, the current reports of extensive drug-resistant (XDR) strain outbreaks are not just a significant central issue in Pakistan but additionally affect public health across the world. The MDR S. Typhi Strains consist of the H58 (Haplotype) lineage and are associated with the IncHI1 plasmid, which also resists chloramphenicol, ampicillin, trimethoprim, and sulfamethoxazole and also shows resistance against fluoroquinolones. The XDR S. Typhi Strains carry the IncHI1 and IncY plasmids, which encode several antibiotic resistance genes. The IncY plasmid carries genes that resist the genes qnrS1 for quinolone resistance and blaCTX-M-15, an extended-spectrum beta-lactamase (ESBL). The point mutation that occurred on the AcrB R717Q/L gene also showed resistance against azithromycin. Azithromycin and carbapenems are helpful medications that are generally used for typhoid treatment. The increasing fluoroquinolone non-susceptibility rates and medical shortcomings brought on by azithromycin. The XDR S. Typhi Strains also show resistance to azithromycin and carbapenems due to the irregular use of medication, which creates big problems for public health. In this review, we also observed that XDR S. Typhi strains are reported in other countries, with a history of patients traveling from Pakistan. In some areas, the XDR S. Typhi has not emerged before its exposure, we need to take some precautions, and the health authorities are responsible for controlling the XDR S. Typhi exposure.
Formulating specific SOPs, raising community awareness about XDR S.Typhi, and executing prevention strategies are vital steps, especially in Pakistan because where drug resistance is common, due to self-medication and improper antibiotic practices.