Lactic Acid Bacteria Antagonism of Acid-tolerant and Antibiotic-resistant Nonstaphylococcal Pathogenic Species Isolated from a Fermented Cereal Beverage using Baird-Parker Agar
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Date
2010
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of agricultural and food chemistry
Abstract
Fermented foods may contain acid-tolerant and antibiotic-resistant pathogenic
microorganisms. Pathogens can be antagonized by lactic acid bacteria, resulting in improved microbiological safety. This
study assessed the antagonistic effects of selected lactic acid bacteria against pathogenic bacteria isolated from a cereal
fermented food.
Materials and Methods: Eight presumptive staphylococci isolated from a commercially produced cereal fermented
beverage on Baird-Parker agar supplemented with tellurite were identified using 16S rRNA sequencing. Acid resistance of
the isolates was assessed using acidified media (brain heart infusion broth of pH 3.6 and 1.5% acidity) for 48 h followed by
taking plate counts. Antibiotic resistance (19 antibiotics) was assessed using the disk diffusion assay. A spot-on-the-lawn
method was used to assess antagonistic effects of Lactobacillus plantarum MNC 21, Lactococcus lactis MNC 24, Weissella
confusa MNC 20 and Lactobacillus rhamnosus yoba 2012 against Lysinibacillus macroides, Bacillus subtilis, Enterococcus
faecalis and Escherichia coli.
Results: Presumptive staphylococci were identified as Lysinibacillus macroides (n = 1), Bacillus subtilis (n = 2),
Enterococcus faecalis (n = 4) and Escherichia coli (n = 1). These isolates were acid-tolerant (from 6.3 ±0.9 log cfu/mL at 0
h to 3.6 ±0.9 log cfu/mL at 48 h), antibiotic-resistant (multiple antibiotic resistance index of 0.1–0.5) and their growth was
inhibited by the lactic acid bacteria (inhibition zone diameters of 14–24 mm).
Conclusions: The lactic acid bacteria cultures of MNC 20, MNC 21, MNC 24 and Lactobacillus rhamnosus yoba 2012
can be used in various food fermentations to inhibit growth of bacterial pathogens; thus, improving product safety.
Description
Keywords
Antagonism, Acid-tolerant, Antibiotic-resistant, Lactic acid bacteria, Baird-Parker Agar
Citation
Munyaka, AW, Verlinde, P., Mukisa, IM, Oey, I., Van Loey, A., & Hendrickx, M. (2010). Influence of Thermal Processing on Hydrolysis and Stability of Folate Poly-γ-glutamates in Broccoli (Brassica oleracea var. italica), Carrot (Daucus carota) and Tomato (Lycopersicon esculentum). Journal of agricultural and food chemistry, DOI: 10.52547/nfsr.9.1.31