Antimicrobial Activity of Ohelo Berry (Vaccinium calycinum) Juice against Listeria monocytogenes and Its Potential for Milk Preservation

Abstract

Listeria monocytogenes is a foodborne pathogen and causes illnesses with a high mortality rate in susceptible populations. Several dairy-related outbreaks have been attributed to contamination by L. monocytogenes, which requires antimicrobial interventions to enhance the safety of these products. This study aimed to determine the antimicrobial activity of the ohelo berry (Vaccinium calycinum), a Hawaiian wild relative of cranberry, against L. monocytogenes in culture media and milk products. The effect of ohelo berry juice at its sub-inhibitory concentrations on the physicochemical properties, biofilm formation, and gene expression of L. monocytogenes was also investigated. The minimum inhibitory concentration of ohelo berry juice against L. monocytogenes was 12.5%. The sub-inhibitory concentration of ohelo berry juice (6.25%) significantly increased the auto-aggregation and decreased the hydrophobicity, swimming motility, swarming motility, and biofilm formation capability of L. monocytogenes. The relative expression of genes for motility (flaA), biofilm formation and disinfectant resistance (sigB), invasion (iap), listeriolysin (hly), and phospholipase (plcA) was significantly downregulated in L. monocytogenes treated by the 6.25% juice. L. monocytogenes was significantly inhibited in whole and skim milk supplemented with 50% ohelo berry juice, regardless of the fat content. These findings highlight the potential of ohelo berry as a natural preservative and functional food to prevent L. monocytogenes infection.

Unraveling the Antimicrobial Effectiveness of Coridothymus capitatus Hydrolate against Listeria monocytogenes in Environmental Conditions Encountered in Foods: An In Vitro Study

“…However, the %CSH results in the presence of the highest concentration of CHY (500 µL mL −1 ) ( Figure 3 ), did not show an association with the higher aggregation observed with CLSM analysis ( Figure 2 ). As a confirmation of our results, other authors [ 32 ] have reported that L. monocytogenes ATCC 7644, in presence of cranberry extract, did not show a linear relationship between the increase of cell surface hydrophobicity and auto-aggregation. The authors argued that the association between cell hydrophobicity and aggregation in the presence of environmental stresses may be a strain-dependent trait.…”

Drug synergy discovery of tavaborole and aminoglycosides against Escherichia coli using high throughput screening

“…As previously documented, Biofilm-encased bacteria likely were 10-100 times more than planktonic counterparts to be resistant to conventional antibiotics, inducing recalcitrance and recurrence of biofilm-associated uropathogenic infections (Beebout et al 2019;de Breij et al 2018). Besides, it's been reported that flagella were associated with virulence and played an essential role in colonization, adherence and distribution (Jia et al 2021;Wu et al 2022). When used E. coli Y9395 for the biofilm associated experiments because of its higher biofilm formation capability (Fig.…”

In Vitro Antibacterial Effect of Various Berries on Listeria monocytogenes as Food Borne Patogen

“…Inspite of the conditions of food storage and processing, such as high salt and low temperature, infectious agent can survive and multiply because of its halotolerance and psychrotolerance ability (Jamshidi and Zeinali, 2019;Yap et al, 2021). A sustainable future requires control of antimicrobial resistance (Jeong et al, 2010;Akinduti et al, 2019;Wu et al, 2022).…”

“…Therefore, efficient antimicrobial approaches for preventing food contamination or the occurrence of listeriosis are urgently needed. Today, consumers desire to choose more natural, healthy, and safe food because inappropriate use of antimicrobial agents in food production might result in undesirable residues in food and the emergence of antimicrobial-resistant microorganisms (Wu et al, 2022). Excessive use of antibiotics has become a modern epidemic.…”

“…Consuming synthetic food preservatives may cause health concerns, including potential side effects and increased cancer risks. Thereby, the use of natural antimicrobials in food preservation has attracted increasing attention from scientists, food manufacturers, and consumers (Wu et al, 2022). Increasing interest of natural foods and their antibacterial activity, our research focused of various forms of native berries and ability to inhibit the growth of bacteria L. monocytogenes.…”