A1 Refereed original research article in a scientific journal

High-Throughput Multiplex Detection of Antibiotic-Resistant Genes and Virulence Factors in Escherichia coli Using Digital Multiplex Ligation Assay




AuthorsConforti, Sheena; Orts, Pablo Rossi; Tamminen, Manu; Julian, Timothy R.

PublisherELSEVIER SCIENCE INC

Publishing placeNEW YORK

Publication year2025

JournalJournal of Molecular Diagnostics

Journal name in sourceJOURNAL OF MOLECULAR DIAGNOSTICS

Journal acronymJ MOL DIAGN

Volume27

Issue6

First page 511

Last page524

Number of pages14

ISSN1525-1578

eISSN1943-7811

DOIhttps://doi.org/10.1016/j.jmoldx.2025.03.003

Web address https://doi.org/10.1016/j.jmoldx.2025.03.003

Self-archived copy’s web addresshttps://research.utu.fi/converis/portal/detail/Publication/492264084


Abstract

Escherichia coli causes >400,000 annual deaths in children aged <5 years worldwide, with morbidity and mortality exacerbated by antimicrobial-resistant strains. A high-throughput multiplexing assay called digital multiplex ligation assay (dMLA) was developed to detect simultaneously 43 priority genes in E. coli related to the following: antibiotic resistance (n = 19), virulence factors (n = 16), and phylogroup markers (n = 6) with controls (uidA, gapdh). Genes are detected via PCR amplification of adjacent probe pairs that ligate in the presence of target gene-specific DNA, followed by sequencing of amplicons on short-read sequencers. The assay was tested in technical replicates on 63 synthetic DNA controls, and applied to 58 E. coli, 2 Staphylococcus aureus, 2 Klebsiella pneumoniae, 1 Klebsiella oxytoca, 1 Vibrio cholera, 1 Pseudomonas lurida, and 1 Salmonella enterica isolates in duplicate. Wholegenome sequencing was used to assess specificity and sensitivity. dMLA showed 100% sensitivity and >99.9% specificity and balanced accuracy on synthetic DNA. Balanced accuracy, calculated as the average of sensitivity and specificity, accounts for imbalanced data sets where negative outcomes are significantly more prevalent than positive ones. dMLA achieved a balanced accuracy of 90% for bacterial isolates. The results underline dMLA's effectiveness in high-throughput characterization of E. coli libraries for antimicrobial resistance genes and virulence factors, leveraging sequencing for massively parallel multiplexing of gene regions on multiple samples simultaneously, and are extendable to targets beyond E. coli.


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Last updated on 2025-06-06 at 12:18