The genomic characterization of Salmonella Paratyphi A from an outbreak of enteric fever in Vadodara, India

• Published in: Microbial genomics Vol. 9; no. 1
• Main Authors: Pereira-Dias, Joana, Taneja, Neelam, Mahindroo, Jaspreet, Maheshwari, Geeti, Patel, Padma J, Thu, Trang Nguyen Hoang, Keane, Jacqui, Dyson, Zoe A, Baker, Stephen, Mylona, Elli
• Format: Journal Article
• Language: English
• Published: England Microbiology Society 2023
• Subjects: Disease Outbreaks; Drug Resistance, Bacterial - genetics; Genomics; Humans; India - epidemiology; Salmonella paratyphi A - genetics; Salmonella typhi - genetics; Typhoid Fever - epidemiology; India; Enteric fever; QRDR; Paratyphoid; Outbreak; India
• ISSN: 2057-5858; 2057-5858
• DOI: 10.1099/mgen.0.000914

Typhi (
. Typhi) and Paratyphi A (
. Paratyphi A) are the causative agents of enteric fever, a systemic human disease with a burden of 300 000 cases per year in India. The majority of enteric fever cases are associated with
. Typhi, resulting in a paucity of data regarding
. Paratyphi A, specifically with respect to genomic surveillance and antimicrobial resistance (AMR). Here, we exploited whole-genome sequencing (WGS) to identify
. Paratyphi A genotypes and AMR determinants associated with an outbreak of
. Paratyphi A in Vadodara, India, from December 2018 to December 2019. In total 117 
. Paratyphi A were isolated and genome sequenced, most were genotype 2.4.2 (72.6 % of all cases), which is the globally dominant genotype. The remainder were genotype 2.3 (25.6 %), while only two isolates belonged to genotype 2.4.1. A single base-pair mutation in
, associated with reduced susceptibility to fluoroquinolones, was present in all of the outbreak isolates; with 74.35 % of isolates having a S83F substitution and the remainder having an S83Y substitution. Our surveillance study suggests that
. Paratyphi A is an emergent pathogen in South Asia, which may become increasingly relevant with the introduction of Vi conjugate vaccines.