An electron micrograph of Lactobacillus WIKIMEDIA, MOGANA DAS MURTEY AND PATCHAMUTHU RAMASAMYLactobacillus parafarraginis KU495926, extracted from yogurt, hindered the growth of 14 multidrug-resistant and so-called extended spectrum beta-lactamase (ESBL) bacteria obtained from infected patients at a Washington D.C. hospital, according to Howard University biologists at the annual American Society for Microbiology meeting held in New Orleans this week (June 1-5).
ESBL bacteria make beta-lactamase enzymes, which promote resistance to certain broad-spectrum antibiotics. The researchers found that L. parafarraginis, a gram-positive microbe, produced a substance, likely a bacteriocin—a type of antimicrobial protein—that inhibited the gram-negative ESBL and multidrug-resistant pathogens. According to lead author Rachelle Allen-McFarlane, a graduate student in Broderick Eribo’s lab at Howard, this may be one of few known examples of gram-positive bacteria-derived bacteriocins inhibiting the growth of gram-negative bacteria.
Typically, bacteriocins from one particular strain are only capable of inhibiting closely related strains, Allen-McFarlane tells The Scientist. Most of the time, “gram-positive kills gram-positive,” she explains.
Though it’s rare, it is possible. “My area of interest is to identify bacteriocins from lactic acid bacteria that are capable of inhibiting multi-drug resistant and ESBL ...
