Enhancement of Lactic Acid Bacteria by Gamma Radiation to Inhibit Antibiotic Resistance of some Salmonella spp.

Abstract

Forty nine isolates were isolated from 34 food samples using Salmonella-Shigella medium, 10 of them were identified biochemically as Salmonella sp., two of them were multidrug-resistant, and they showed a resistance to seven tested antibiotics (ampicillin, streptomycin, gentamicin, nalidixic acid, ciprofloxacin, tetracycline, amoxicillin). Molecular identification of these isolates proved that they were Citrobacter ferundii and Proteus mirabilis. The antimicrobial activity for Lactobacillus acidophilus ATCC 4356 and Streptococcus thermophiles ATCC 19987 mixture and their cell-free supernatant mixture were activated by low doses of gamma radiation (5 Gray for lactic acid bacteria & 20 Gray for supernatant). Results proved that on applying the two previously activated mixtures on chicken carcasses, supernatants completely killed the three pathogens (Citrobacter ferundii, Proteus mirabilis and Salmonella typhi ATCC 14028 reference strain) during 4 hours while the lactic acid bacteria mixture killed them after 3 hours.

Effect of gamma irradiated Lactobacillus bacteria as an edible coating on enhancing the storage of tomato under cold storage conditions

“…However, the interaction between irradiation and food components directly could cause the development of undesirable sensory and chemical changes in some foods (Gliemmo, Latorre, Narvaiz, Campos, & Gerschenson, 2015). On the other hand, (Abdallah, Hussein, Khalil, Abdel-Aal, & El-Desokey, 2018) found that gamma irradiation could be used indirectly in food preservation by exposing the supernatant free cells of the probiotics bacteria (Lactic acid bacteria). As the antibacterial activity of the free cell supernatants of the Lactobacillus acidophilus and Streptococcus thermophilus increased by gamma radiation toward Salmonella typhi, Proteus mirabilis, and Citrobacter freundii more than the irradiated suspended LAB cells.…”