Salmonella typhimurium was sensitive to most antibiotics, except aminoglycosides and fluoroquinolones. Credit: Callista Images/ Image Source/ Getty Images
Decoded genomes of major disease-causing bacteria provide new insights into the potency and functions of genes that enable pathogens to resist antibiotics1.
This knowledge will help clinicians to choose appropriate combinations of drugs to improve outcomes for infections such as sepsis, says a research team at the Translational Health Science and Technology Institute in Faridabad.
In a multicentre study, the scientists, led by Bhabatosh Das, sequenced the whole genomes of Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Salmonella enterica, which infect the intestinal and urinary tracts, and respiratory organs and can trigger sepsis. They found several acquired antibiotic-resistance genes (ARGs) that were pathogen-specific and displayed region-specific signatures.
The team identified different mobile genetic elements (MGEs) that played a vital role in the rapid spread of ARGs between bacterial species. MGEs are parts of DNA that move within the genome or between cells. Regardless of the type of ARG, the MGEs linked with ARGs were also pathogen-specific.
The researchers tested which pathogens were susceptible or resistant to 17 commonly used antibiotics. Salmonella typhimurium was susceptible to most antibiotics, except aminoglycosides and fluoroquinolones. E. coli, P. aeruginosa, and A. baumannii were designated as multidrug-resistant pathogens as they were resistant to multiple classes of antibiotics.
Analysis of the drug-resistant bacterial strains further revealed that the ARGs were functional and expressed differentially in the presence and absence of different classes of antibiotics.
