Due to the scarcity of systematic review on the temporal trends in the development of antimicrobial resistance (AMR) among Salmonella Typhi and Salmonella Paratyphi in India, the researchers of the current study identified the setrends (phenotypic and molecular mechanisms) systematically in bacterial isolates from Indian patients with enteric fever over two decades. Resistance patterns among 4,611 individual S. Typhi isolates and 800 S. Paratyphi A isolates, reported from 1992 to 2017 in 40 publications were analyzed. Molecular resistance determinants were extracted from 22 publications and also reviewed as per the PRISMA guidelines. The analyses suggested that multidrug-resistant enteric fever was declining in India and being replaced by fluoroquinolone resistance. Fundamental mechanisms responsible for fluoroquinolone resistance were mutations in gyrA and parC. Multidrug-resistance was driven mainly by resistance determinants encoded on mobile genetic elements. These findings reflect the effect of antimicrobial pressure, which has been causing antimicrobial resistance in typhoidal Salmonella in India. It is essential to understand these trends to plan future therapy approaches, which help evaluate the impact of new typhoid conjugate vaccines against these resistant organisms.

Source: Indian J Med Res. 2019 Feb;149(2):151-163.