November 18, 2011
Targeting Bacterial Gas Defenses Allow For Increased Efficacy Of Numerous Antibiotics
Researchers discover role of H2S as defense mechanism against oxidative stress and antibiotics
Although scientists have known for centuries that many bacteria produce hydrogen sulfide (H2S) it was thought to be simply a toxic by-product of cellular activity. Now, researchers at NYU School of Medicine have discovered H2S in fact plays a major role in protecting bacteria from the effects of numerous different antibiotics.
"Surprisingly little has been known about H2S biochemistry and physiology in common bacteria" said Dr. Nudler. "We are excited about the potential impact this research may have on the growing problem of microbial resistance. These findings suggest a conceptually new approach, an adjuvant therapy that targets bacterial gas defenses and thus increases the efficacy of many clinically used antibiotics."
More specifically, the study showed that integrated mechanism of H2S-mediated protection against oxidative stress also protects against antibiotics. The research provides direct support for the emerging concept of the pro-oxidative action of many antibiotics. In addition, the study demonstrates that bacteria that generate both H2S and nitric oxide (NO) simultaneously, such as B. anthracis (a causative of anthrax), cannot survive without both gases, even under normal growth conditions. One gas makes up for the lack of the other and at least one of them is essential.
In a previous study Dr. Nudler and his colleagues demonstrated that NO plays a similar role in protecting bacteria from antibiotics (Science September 9, 2009). However, because NO is present in only a limited number of bacteria while hydrogen sulfide synthesis occurs in essentially all bacteria, the practical implications of this new finding is extremely wide-ranging.
On the Net: