TY - JOUR
T1 - In vitro evaluation of the antimicrobial activity of a range of probiotics against pathogens
T2 - evidence for the effects of organic acids
AU - Tejero-Sariñena, Sandra
AU - Barlow, Janine
AU - Costabile, Adele
AU - Gibson, Glenn R
AU - Rowland, Ian
N1 - Copyright © 2012 Elsevier Ltd. All rights reserved.
PY - 2012/10
Y1 - 2012/10
N2 - The aim of this study was to investigate the antimicrobial properties of fifteen selected strains belonging to the Lactobacillus, Bifidobacterium, Lactococcus, Streptococcus and Bacillus genera against Gram-positive and Gram-negative pathogenic bacteria. In vitro antibacterial activity was initially investigated by an agar spot method. Results from the agar spot test showed that most of the selected strains were able to produce active compounds on solid media with antagonistic properties against Salmonella Typhimurium, Escherichia coli, Enterococcus faecalis, Staphylococcus aureus and Clostridium difficile. These results were also confirmed when cell-free culture supernatants (CFCS) from the putative probiotics were used in an agar well diffusion assay. Neutralization of the culture supernatants with alkali reduced the antagonistic effects. These experiments are able to confirm the capacity of potential probiotics to inhibit selected pathogens. One of the main inhibitory mechanisms may result from the production of organic acids from glucose fermentation and consequent lowering of culture pH. This observation was confirmed when the profile of organic acids was analysed demonstrating that lactic and acetic acid were the principal end products of probiotic metabolism. Furthermore, the assessment of the haemolytic activity and the susceptibility of the strains to the most commonly used antimicrobials, considered as basic safety aspects, were also studied. The observed antimicrobial activity was mainly genus-specific, additionally significant differences could be observed among species.
AB - The aim of this study was to investigate the antimicrobial properties of fifteen selected strains belonging to the Lactobacillus, Bifidobacterium, Lactococcus, Streptococcus and Bacillus genera against Gram-positive and Gram-negative pathogenic bacteria. In vitro antibacterial activity was initially investigated by an agar spot method. Results from the agar spot test showed that most of the selected strains were able to produce active compounds on solid media with antagonistic properties against Salmonella Typhimurium, Escherichia coli, Enterococcus faecalis, Staphylococcus aureus and Clostridium difficile. These results were also confirmed when cell-free culture supernatants (CFCS) from the putative probiotics were used in an agar well diffusion assay. Neutralization of the culture supernatants with alkali reduced the antagonistic effects. These experiments are able to confirm the capacity of potential probiotics to inhibit selected pathogens. One of the main inhibitory mechanisms may result from the production of organic acids from glucose fermentation and consequent lowering of culture pH. This observation was confirmed when the profile of organic acids was analysed demonstrating that lactic and acetic acid were the principal end products of probiotic metabolism. Furthermore, the assessment of the haemolytic activity and the susceptibility of the strains to the most commonly used antimicrobials, considered as basic safety aspects, were also studied. The observed antimicrobial activity was mainly genus-specific, additionally significant differences could be observed among species.
KW - Adult
KW - Anti-Infective Agents
KW - Antibiosis
KW - Bacillus
KW - Carboxylic Acids
KW - Clostridium difficile
KW - Enterobacteriaceae
KW - Enterococcus faecalis
KW - Humans
KW - Infant
KW - Lactobacillales
KW - Microbial Sensitivity Tests
KW - Probiotics
KW - Staphylococcus aureus
KW - Streptococcus
UR - https://www.scopus.com/pages/publications/84867330378
U2 - 10.1016/j.anaerobe.2012.08.004
DO - 10.1016/j.anaerobe.2012.08.004
M3 - Article
C2 - 22959627
SN - 1075-9964
VL - 18
SP - 530
EP - 538
JO - Anaerobe
JF - Anaerobe
IS - 5
ER -