Antibiotics Trigger Bacterial Stress, Drug-Resistance
Stress from antibiotics help bacteria take up new DNA, potential drug resistance genes
MONDAY, July 10 (HealthDay News) -- Antibiotic exposure can trigger Streptococcus pneumoniae to undergo genetic transformation, a stress response that allows the bacteria to take up new DNA and potentially become drug resistant, according to a report in the July 7 issue of Science.
Jean-Pierre Claverys, of the Laboratoire de Microbiologie et Genetique Moleculaires in Toulouse, France, and colleagues showed that the stress-inducing, DNA-damaging agent mitomycin C induced S. pneumoniae cultures to kill neighboring bacteria and take up their DNA.
These effects required activation of the com regulon, which includes genes responsible for genetic recombination, allowing the bacteria to diversify its own DNA. Antibiotics including the protein synthesis inhibitors kanamycin and streptomycin, and the fluoroquinolones levofloxacin and moxifloxacin used to treat upper respiratory tract infections, also caused the bacteria to undergo the process.
"The high incidence of asymptomatic carriage of this pathogen is a major concern, because inappropriate antibiotic treatments could accelerate the occurrence of additional resistant clones and promote the evolution of virulence," the authors conclude.