Inhibition of Cronobacter sakazakii by Lactobacillus acidophilus n.v. Er2 317/402

Abstract

Lactobacillus acidophilus n.v. Er2 317/402 strain Narine is known as a health beneficial functional probiotic culture and supplementary source of nutrition for newborns. In this study, in vitro antimicrobial activities of Narine-lyophilized (Narine-L), Narine-heat treated (Narine-HT), and Narine crude cell-free extract (Narine-CCFE) were evaluated against pathogen Cronobacter sakazakii (C. sakazakii) in agar as well as in a reconstituted powdered infant formula (RPIF) model. Inhibition zones of 30 mg Narine-L and Narine-HT were both 150 U, whereas inhibition zone of 30 mg Narine-CCFE was 200 U. Narine-L (1 g) and Narine-HT (1 g) were added to 10 mL of artificially contaminated RPIF, respectively, containing 100 μL of C. sakazakii (1.62×108 colony forming unit (CFU)/mL). After treatment with Narine-L and Narine-HT for 3 h and 6 h at 37℃, less than ≤107 CFU/mL of C. sakazakii was detected in RPIF. Without Narine-L and Narine-HT treatment, the population of C. sakazakii increased up to 5.36×109 CFU/mL after 6 h. Examination by transmission electron microscopy confirmed C. sakazakii cells were damaged by Narine-CCFE. Thus, employing Narine culture as a natural and safe bio-preservative may protect infants from C. sakazakii.

The Antimicrobial Activity of Lactobacillus Acidophilus Against Intestinal and Foodborne Pathogens

“…C.sakazakii it is an opportunistic human and food-borne pathogen. The organism can be found in broad range of food including powdered infant formula (PIF) , cheese, meat, vegetables, grain, herbs , spices , tomato , water and households [23,24] These results coincides with pervious study which shown that Lactobacillus acidophilus has ability to inhibit and safe bio-preservative protect infants from C.sakazakii [25,26].…”

Postbiotics against Pathogens Commonly Involved in Pediatric Infectious Diseases

“…Growing concerns over emerging antibiotic resistance coupled with the high risk of Cronobacter sakazakii infections in formula-fed infants have led to new studies investigating the efficacy of postbiotics produced by different probiotic strains against C. sakazakii [ 90 ]. For instance, lyophilized and heat-treated probiotic Lactobacillus acidophilus INMIA 9602 Er 317/402 (strain Narine) proved to inhibit the growth of C. sakazakii in contaminated reconstructed powdered infant formula after coculture for 6 h at 37 °C [ 65 ]. However, when employing the agar well diffusion method, CFS Narine was the most effective in inhibiting C. sakazakii growth compared to lyophilized and heat-treated Narine.…”

Natural Compounds With Antibacterial Activity Against Cronobacter spp. in Powdered Infant Formula: A Review

“…Antimicrobial effects were attributed to antimicrobial peptides (caseicin A & B) derived from the degradation of bovine casein by microbial enzymes. Charchoghlyan et al (89) found that a purified heat inactivated aqueous extract of skim milk fermented with a commercial probiotic strain of Lactobacillus acidophilus used to supplement PIF also inactivated C. sakazakii in the reconstituted product stored at 37 • C. The composition of the extract was not provided by the authors of the study, who offered that acids released during fermentation were likely responsible for antibacterial effects. A similar conclusion was reached by Kim et al (90) derived from any microbial species is a barrier to broader food applications.…”