# Genotype characteristics of two non traveler sources burkholderia pseudomallei strains isolated from clinical patients for the first time in Chongqing, China

## TL;DR

Two new Burkholderia pseudomallei strains were identified in Chongqing, China, showing genetic differences and antibiotic sensitivity, suggesting a potential rise in melioidosis due to climate change.

## Contribution

First report of non-traveler B. pseudomallei infections in Chongqing, with genomic and antibiotic sensitivity analysis of two novel strains.

## Key findings

- The two B. pseudomallei strains showed significant genetic differences with 17,197 SNPs and one novel sequence type (ST2149).
- Both strains were sensitive to common antibiotics despite carrying beta-lactam resistance genes.
- Strain CQ2024Bp-002 lacked certain virulence genes (boaB and wzt2) compared to CQ2024Bp-001.

## Abstract

In 2024, two cases of melioidosis were discovered in Chongqing, China. This was the first instance of non-traveler infection cases being found in this region. The strain characteristics and phylogenetic relationships of the two B. pseudomallei (CQ2024Bp-001 and CQ2024Bp-002) remained poorly understood. An antibiotic sensitivity test, genomic sequencing, prediction of virulence genes and ARGs, wgSNP, and MLST were performed for the two strains. The results indicated that the two strains had significant genetic differences (17197 SNPs), and CQ2024Bp-002 was a novel sequence type (ST2149). CQ2024Bp-001 carried blaOXA-59 and blaOXA-57, while CQ2024Bp-002 only carried blaOXA-59. Despite carrying \documentclass[12pt]{minimal}
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\begin{document}$$\beta$$\end{document}-lactam resistance genes, both strains were sensitive to common antibiotics (TIM, CAZ, MEM, MH, LEV, SXT, and CPL). Their virulence genes differed, with CQ2024Bp-002 lacking boaB and wzt2. The clustering analysis based on wgSNP revealed that the two strains were distant from each other. These findings suggest that under the influence of global warming, non-endemic areas of melioidosis are gradually developing conditions suitable for the reproduction and transmission of B. pseudomallei, potentially leading to an increase in melioidosis cases. It highlights the need for an active monitoring system to be established in climate-sensitive areas to prevent and control the potential regional epidemic of melioidosis.