How do Bacteria Become Antibiotic Resistant?

Recently, I just discovered a study from Harvard Researchers that uses genome sequencing to investigate the genetic basis for antibiotic resistance in E. coli.

The authors used continuous culture systems that are slowly increasing the concentrations of three different antibiotics, separately. They observed that the resistance increased significantly over a period of approx. 20 days. And by sequencing the genomes of the resistant populations on GAIIx, they found in total 47 SNPs contributing to the resistances.

In trimethoprim-resistant bacteria most of the mutations occurred in the E. coli gene encoding the target enzyme that is normally inhibited by the antibiotic compound. In bacterial populations resistant to the antibiotics chloramphenicol and doxycycline, in contrast, the mutations accumulate in a broad spectrum of genes involved in translation, transcription and protein transport. This is consistent with chloramphenicol and doxycycline being inhibitors of protein synthesis.

This is of high importance since the prevalence of resistant bacteria is continuously increasing. As a result, in more and more cases, the standard antibiotics are no longer effective to treat seriously ill patients. New findings in antibacterial research are crucial to stop this progression as soon as possible.