Secrets of antibiotic resistance

Since the advent of penicillin, researchers have recognized that, when nutrients are limited, many species of bacteria can slow their growth and resist being killed by antibiotics. Now, two new reports published in Science , reveal new insights into the specific ways in which bacterial species carry out this process.

In the first study, the team of Dao Nguyen, University McGill University in Montreal (Canada), explained that the bacteria Pseudomonas aeruginosa and Escherichia coli have mechanisms that detect nutrient deficiencies. When nutrients are limited by antibiotics, it triggers a response that modifies the transcription of certain genes of the bacteria. And according to the researchers, this process allows the bacteria to survive and resist a wide range of antibiotics. Nguyen and colleagues also found that the mutant bacteria unable to identify the constraints of nutrients in the environment, were much more sensitive to antibiotics and less able to cause infection.

In other work, the team of Konstantin Shatalin, Genetics Research Institute in Moscow (Russia), discussed the role of hydrogen sulfide production in various species of bacteria. Experts have found that the loss of key bacterial enzymes involved in the production of gas is sufficient for many bacteria are susceptible to a wide range of treatments with antibiotics. They also noted, however, that if these mutant bacteria are supplied with an external source of hydrogen sulfide, its resistance to antibiotics could be restored.