Assessing sensitivity of campylobacter jejuni to anti-microbe effects to reduce risks of food prodycts contamination with campylobacteriosis agents

Abstract

We aimed to assess efficiency of various anti-microbe effects on pathogenic microflora; to do that, we performed com-parative study on how sensitive Campylobacter jejuni test strains were to ultraviolet radiation and biocides based on peracetic acid (PAA). PAA-based biocides suppressed significant numbers of Campylobacter; however, preset treating modes didn’t allow achieving complete inactivation of the test strains. Efficiency of effects produced by ultraviolet radiation on C.jejuni strains depended on exposure duration: 20-minute treatment of plates with broth bacterial suspensions caused a decrease in a number of viable cells which was equal to 1.5–2,0 logarithmic orders; 60-minute treatment resulted in a decrease in C.jejuni contents that amounted to less than 200 CFU/cm3. Polypeptide antibiotics produced by lactic-acid bacteria (bacteriocins, nisin, etc.) have some useful properties and it makes them applicable for suppressing adverse microflora in food products manufacture. We applied an ‘associate growth” model to examine peculiarities related to C.jejuni growth in milk that, beside this pathogen, was simultaneously inoculated with mesophilic lactic-acid lactococci or thermophilic lactic-acid bacteria that were bacteriocins producers. Depending on quantity of introduced lactic-acid bacteria, such as Lactobacillusplantarum, Lactobacilluslactis and Lactococcuslactis, C.jejuni growth was substantially inhibited. We revealed a relationship between anti-bacterial activity and nature of inhibiting effects and concentrations of the above-mentioned lactic-acid microorganisms, temperature, an amount of time during mixed cultures were cultivated together, and properties of used strains which became the most apparent when lactobacteria were introduced in a dose equal to 108 CFU/cm3. Our study on an ability of C.jejuni to survive under exposure to an adverse environment revealed that microbe populations had variable physiological properties, Campylobacter were greatly resistant, and it was difficult to make a relevant choice on efficient tools and procedures for anti-microbe treatment.

Keywords

• campylobacter jejuni
• in vitro model
• biocides
• anti-microbe effects
• ultraviolet radiation
• contamination
• biofilms
• lactic-acid bacteria