کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
3395286 1221680 2012 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
In vitro evaluation of the antimicrobial activity of a range of probiotics against pathogens: Evidence for the effects of organic acids
موضوعات مرتبط
علوم زیستی و بیوفناوری ایمنی شناسی و میکروب شناسی میکروب شناسی
پیش نمایش صفحه اول مقاله
In vitro evaluation of the antimicrobial activity of a range of probiotics against pathogens: Evidence for the effects of organic acids
چکیده انگلیسی

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.


► Antimicrobial activity of 15 probiotics against Gram-positive and Gram-negative pathogens.
► Main inhibitory mechanism: low pH from production of organic acids, mainly lactic and acetic acids.
► The observed antimicrobial activity was mainly genus-specific.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Anaerobe - Volume 18, Issue 5, October 2012, Pages 530–538
نویسندگان
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