The concept of using bacteriophages to improve the microbiological quality of minimally processed foods

Abstract

Phages were discovered relatively recently -at the turn of the 19th and 20th centuries. The idea of using bacteriophages for therapeutic purposes was promoted by d'Herelle, who conducted the first successful experiments with prokaryotic viruses. Works of contemporary scientists on phage therapy were, however, halted due to the discovery of penicillin by Alexander Fleming in 1928. Today, when many bacterial strains have developed resistance to common antibiotics offered by the pharmaceutical industry and when new, so far unknown, bacterial strains have appeared, the concept of using bacteriophages to treat bacterial infections has been revived. Considering the food sector, the search for novel solutions that would ensure the appropriate microbiological quality of minimally processed foods may bring an effective method for eradicating bacterial pathogens that induce food-borne infections. The employment of chemical and physical methods of food preservation often lead to the deterioration of its nutritive value and of its physical and organoleptic properties. Minimally processed foods manufactured without any drastic preservation methods can be especially at risk of developing microorganisms, including the pathogenic ones. Low-temperature production processes and cold-storage facilitate the development of psychrophilic microorganisms, while another threat is posed by the high microbiological contamination of raw materials. This work presents a biological method for the eradication of bacteria most commonly found in a food-based environment. The study concept postulated the use of bacteriophages to improve the microbiological quality of food, with special attention paid to minimally processed foods.

Transcriptional Regulation of the Multiple Resistance Mechanisms in Salmonella—A Review

“…Bacteria achieve genetic variabilities, such as virulence or antibiotic resistance by horizontal gene transfer (HGT) [ 13 , 14 ]; however, incorrect expression of the newly acquired genes may be harmful to the bacteria. Global transcriptional regulator, H-NS, helps bacteria survive stressful conditions by suppressing the expression of acquired genes [ 26 , 150 ].…”

“…The widespread use of antibiotics, especially those with a broad spectrum of activity, contributes to the development of specialist drug defense strategies by pathogens [ 12 , 13 ]. The mechanisms of antibiotic resistance are then disseminated in the environment by horizontal gene transfer (HGT) between bacteria and, for example, by lysogenic phages [ 13 , 14 ]. The primary and common mechanism of bacterial resistance to antimicrobial agents is multidrug efflux systems [ 15 , 16 ].…”

Wykorzystanie fagów litycznych do ograniczania liczby pałeczek Salmonella w roślinnej matrycy żywnościowej

“…Wykorzystanie bakteriofagów jako biologicznej metody eliminacji bakteryjnych patogenów żywności jest stosunkowo nową koncepcją utrwalania żywności. Na świecie dostępny jest szereg komercyjnych preparatów bakteriofagowych przeznaczonych dla przemysłu spożywczego [33]. Wykorzystanie bakteriofagów umożliwia regulację zanieczyszczenia opornymi szczepami bakterii (np.…”

“…Fagi mogą rozwijać się jedynie w komórkach bakteryjnych, zatem nie oddziałują na komórki człowieka. Dzię-ki szczepowej specyficzności nie niszczą naturalnej mikroflory jelitowej ludzi i zwierząt [10,22,33]. W preparatach bakteriofagowych stosowane są jedynie fagi lityczne, co zapobiega nabywaniu przez bakterie oporności oraz horyzontalnemu transferowi genów [18,33].…”

“…Według Wanga i Saboura [31] optymalne pH większości bakteriofagów zawiera się w zakresie 5 ÷ 8. Obniżenie temperatury rozszerza zakres tolerancji pH od 4 do 10 [33]. Zbyt kwaśne środowisko wpływa prawdopodobnie na denaturację białek wirionu, a zdolność do przeżycia w szerokim zakresie pH jest cechą wymaganą w biokontroli [29].…”