Scanning electron micrograph of Pseudomonas aeruginosaCDC, JANICE HANEY CARRCertain mutations that seem to confer antibiotic resistance in three different pathogenic bacterial species also provide a growth advantage and increased virulence during an infection, according to a study published in Science Translational Medicine today (July 22). While there are many well-known examples of antibiotic-resistance mutations that reduce bacterial fitness, scientists at the Brigham and Women’s Hospital and Harvard Medical School and their colleagues have found that some antibiotic-resistant pathogenic bacteria outgrow their antibiotic-sensitive counterparts, even in the absence of antibiotic selection.
“This study calls into question the concept that antibiotic resistance leads to less virulence,” said Stuart Levy, a microbiologist who studies antibiotic resistance at the Tufts University School of Medicine and was not involved in the study. However, he noted, this study is not the first to report evidence of mutations that both provide resistance and boost the fitness of certain pathogenic microorganisms.
Many microbiologists have assumed that because antibiotic-resistant strains of bacteria are typically at a disadvantage when it comes to growth, halting the use of antibiotics could weed out such resistance, mitigating concerns tied to the rising numbers of drug-resistant infections. “[This study] leads to the question of whether that strategy would work,” said Amy Anderson, who studies anti-infective resistance at the University ...
