In vitro evaluation of probiotic potential of five lactic acid bacteria and their antimicrobial activity against some enteric and food-borne pathogens

Abstract

Lactic acid bacteria (LAB) present many important properties in food manufacturing, such as improvement of physical characteristics and the production of lactic acid that aids in the increase of the shelf life of food products. Also, LAB can suppress growth of pathogens, control of serum cholesterol level, modulate immune system, and improve lactose digestion. Five standard (Lactobacillus paracasei, Lactobacillus helveticus, Lactobacillus fermentum, Bifidobacterium longum and Lactococcus lactis) lactic acid bacterial strains were screened for probiotic potential properties and their ability to antagonize the growth of some enteric pathogens isolated from patients suffering from acute gastroenteritis. The five strains of LAB were resistant to acidic pH and bile salts. Lactobacillus strains showed protein and starch digesting capability on agar plate while B. longum ATCC 15707 and L. lactis subsp. lactis ATCC 11454 showed only protein digestion. In addition, Lactobacillus strains showed antagonistic effects against all pathogenic strains tested. L. paracasei and L. helveticus [culture and cell-free culture supernatant (CFCS)] exhibited the highest antagonistic activity against the tested pathogens followed by L. fermentum. While B. longum and L. lactis subsp. lactis showed weak or no activity against the tested strains. L. paracasei, L. helveticus, and L. fermentum showed potential to be used as probiotic strains with considerable good antagonistic activity against the most important enteric pathogens.

Characterization and Antibacterial Potential of Lactic Acid Bacterium Pediococcus pentosaceus 4I1 Isolated from Freshwater Fish Zacco koreanus

“…Lactic acid bacteria (LAB) have proven efficacies for food preservation and enhance the nutritive quality of a variety of fermented food products (Gad et al, 2016). Primarily, the LAB exert their antimicrobial effects by producing lactic acid, which increases the acidity of their environment, thereby resulting in the loss of the viabilities of pathogenic bacteria (Ammor et al, 2006; Gad et al, 2016).…”

“…Primarily, the LAB exert their antimicrobial effects by producing lactic acid, which increases the acidity of their environment, thereby resulting in the loss of the viabilities of pathogenic bacteria (Ammor et al, 2006; Gad et al, 2016). Low molecular weight compounds, such as, hydrogen peroxide, carbon dioxide, diacetyl (2,3-butanedione), and bacteriocins also contribute to antimicrobial effects of LAB (Ammor et al, 2006; Sankarankutty and Palav, 2016), as they substantially inhibit the growths of pathogenic bacteria in food system.…”

“…Recently, severe concerns have been expressed regarding the increasing incidences of diseases associated with foodborne pathogens (Oussalah et al, 2007; da Silveira et al, 2012; Gad et al, 2016). Although adequate biopreservation techniques can prevent food contamination by pathogens, food processors are frequently confronted by situations involving food contamination by pathogenic microorganisms (Runyoro et al, 2010).…”

Lactobacilli From Buffalo Milk and Yogurt With Antibacterial Activity Against Gram-Negative Uropathogens

“…In a study from Egypt, the highest antagonistic activity was observed for Lactobacillus paracasei and L. helveticus against the tested pathogens followed by L. fermentum, while Bifidobacterium longum and L. lactis subsp. lactis showed weak or no antibacterial activity against the tested strains (23).…”

Effect of a Laminarin Rich Macroalgal Extract on the Caecal and Colonic Microbiota in the Post-Weaned Pig

“…Intestinal microorganisms are important in terms of regulating digestion and improving host performance through the fermentation of non-digestible polysaccharides, resulting in the production of beneficial volatile fatty acids (VFA), particularly butyrate [5,7]. Furthermore, the colonisation of the intestinal mucosa and lumen by commensal bacteria reduces the accessibility of pathogens to both nutrients and attachment sites [8,9]. Marine macroalgal derivatives have been considered as potential bioactive compounds in swine nutrition and in particular as a prebiotic that can favourably support the intestinal microbiome [4,10,11].…”