Lactobacillus isolate inhibits multi-drug resistant bacteria
by Molly Walker, Staff Writer, MedPage Today June 04, 2017
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• Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

NEW ORLEANS — Researchers here may have found an unlikely ally in their fight against antibiotic-resistant pathogens — commercial yogurt.
A Lactobacillus isolate was found to inhibit the growth of several multi-drug resistant and extended spectrum beta-lactamase bacteria derived from patient samples at a Washington hospital, reported Rachelle Allen-McFarlane, a doctoral student at Howard University in Washington, and colleagues, in a poster presentation at the ASM Microbe meeting.
At an expert media session, David Relman, MD, of Stanford University in Stanford, Calif., and a meeting vice chair said that there are known beneficial organisms in some foods, such as yogurt, because fermented foods tend to contain organisms that have been associated with beneficial properties. He cited this study in particular in terms of aiding potential “drug discovery.”
Relman added that the positive properties of Lactobacillus are well-known. Prior research several years ago identified a different Lactobacillus species that normally lives in the vagina. It produced an antibiotic called lactocillin that kills off E. coli bacteria, but doesn’t touch the other normal, healthy vaginal bacteria.
Other research on different species of Lactobacillus shows that it may affect a woman’s risk of contracting HIV, as well as play a role in helping to prevent preterm birth.
“This yogurt organism is to presumably serve that Lactobacillus in its natural environment and to protect it from competitors,” Relman said. “They’re all doing interesting things, and a lot of them are in food. We just have to figure out how to select the right ones for the right properties and ensure that we’re not killing them by mistake.”
Allen-McFarlane’s group isolated 68 lactic acid bacteria from commercial yogurt and cheese. They were screened for antimicrobial activity against Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli (O157:H7). Screening of the antimicrobial activity was via spot and well-diffusion assays.
The isolate was identified as Lactobacillus parafarranginis KU495926 and it inhibited 14 multi-drug resistant and extended spectrum beta-lactamase bacteria, which are known for breaking down antibiotics. The 14 isolates were comprised of:
• Escherichia coli (5)
• Pseudomonas aeruginosa (2)
• Acinetobacter baumannii/haemolyticus (3)
• Enterobacter aerogenes (1)
• Proteus mirabilis (2)
• Klebsiella pneumoniae (1)
The authors said that the inhibitory substance may be a unique, bacteriocin-like peptide, or a protein produced by bacteria of one strain that is active against those of a closely related strain. It is heat stable up to 121° C.
These results suggested that Lactobacillus parafarranginis KU495926 may be a novel strain that could be worth exploiting for the development of potential therapies in the fight against antibiotic resistance, the authors said.
“Considering the current upsurge of antibiotic resistance in hospitals, especially among the gram-negative bacteria, and the exigent need to find viable alternatives, findings from the study may hold promise for possible therapeutic application,” said Allen-McFarlane in a statement.

last updated 06.04.2017
• Primary Source
ASM Microbe
Source Reference: Allen-McFarlane R, et al “Lactobacillus parafarraginis KU495926 inhibits multi-drug resistant and extended spectrum beta-lactamase producing gram-negative bacteria” ASM Microbe 2017; Abstract 20.