Cronobacter sakazakii—biological properties and sanitary-epidemiological significance

The actual regulatory documents regulate the content of the Enterobacter sakazakii microorganism (actual name Cronobacter sakazakii) in milk products intended for the nutrition of young children, including premature infants. We analyzed the literature data on the spread, biological properties and virulence factors of this microorganism, the current regulatory documents regulating the content of C. sakazakii in food, methods of its isolation and identification. C sakazakii is a gram–negative rod-shaped non-spore-forming facultative anaerobe, 3x1 µm, motile due to peritrichial flagella. Colonies with a diameter of 2-3 mm are formed on tryptocasein-soy agar during incubation at a temperature of 36°C for 24 hours. When incubated at 25°C, a bright yellow pigment forms on the colonies after 48 hours. Although C. sakazakii is an opportunistic microorganism, it has virulence factors and is capable of forming a biofilm with a spongy structure that adsorbs water. Thus, microorganisms are protected from drying out and are able to survive on the surface of technological equipment for a long time and be a constant factor in food contamination. C. sakazakii, when exposed to stress factors such as heating or drying, can enter a viable but uncultivable state, which significantly complicates the detection of this microorganism in food. Due to the presence of virulence factors C. sakazakii is capable of causing diseases such as meningitis, necrotizing enterocolitis and bacteremia in people with impaired immunity, newborns and premature infants. C. sakazakii is not only a medical problem, it can contaminate fertilized chicken eggs, which leads to increased mortality of embryos, hatching of weak chickens, giving low weight gain, their high mortality. It has been established that in order to return to the cultivable form of Cronobacter strains, it is necessary to have ferrioxamine E in a concentration of 150 ng/ml in enrichment media, however, the regulatory documents in force in our country do not provide for the addition of ferrioxamine E to nutrient media, which reduces the likelihood of detecting uncultivated forms of C. sakazakii in food.

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