Evidence Hub

Analysis of chromosomal genes and proteins of gyrA and gyrB from Indonesian Local-Strain Salmonella enterica serovar Typhi

Anggelia Wijaya, Ita M. Nainggolan, Ignes Nathania, Anita D. Krishnan Thantry, L. Moehario

Journal of Infection in Developing Countries, 2026

Abstract

INTRODUCTION

Typhoid fever is an infection of the gastrointestinal tract caused by Salmonella Typhi. Ciprofloxacin is the most widely used second-line therapy; it provides good results in therapy. Indonesia has a unique resistance pattern of fluoroquinolones. Earlier studies of the gyrA and gyrB from local S. Typhi strains showed no mutation, and amino acid replacement was identified in all reported codons. In this study, we explored the whole sequence of the gyrA and gyrB further to understand the association of the unique characteristics of our local strains with fluoroquinolone resistance.

METHODOLOGY

This was an analytical study with a cross-sectional approach. Isolates collection, identification, antibiotic sensitivity test, DNA extraction, gene amplification, purification, and sequencing were carried out. Bioedit was used for the analysis of sequencing data.

RESULTS

Four isolates were identified as S. Typhi. Three isolates were sensitive to nalidixic acid, ciprofloxacin, levofloxacin, and moxifloxacin. One isolate was intermediate to nalidixic acid, ciprofloxacin, levofloxacin, and resistant to moxifloxacin. The gyrA and gyrB genes were aligned with S. Typhi Ty2 reference sequence (NCBI GenBank AE014613.1). Three amino acid changes (Gly133Glu, Asn538Asp, and Thr856Ala) and one amino acid change (Ala416Ser) were found in gyrA and gyrB, respectively. Protein secondary structures of these isolates showed some changes in alpha helices, beta sheets, random coils, and beta…

How strong is the evidence?

Evidence Hub reads this as a cross-sectional, done in people. Its evidence level is 4 of 5 (Low · observational). Observational designs can show an association but not prove cause.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free