Survival of viable but nonculturable Cronobacter sakazakii in macrophages contributes to infections.

Cronobacter sakazakii (C. sakazakii), a pathogen that exists in dry and low-moisture environments, such as powder infant formula (PIF), can enter a viable but nonculturable (VBNC) state under harsh conditions, which enables it to escape traditional detection methods and thus poses a potential public health risk. This study aimed at assessing the virulent nature of VBNC C.

Inhibitory mechanism of lactoferrin on antibacterial activity of oenothein B: isothermal titration calorimetry and computational docking simulation.

Background: Many foods contain proteins and polyphenols, but there is a poor understanding of the nature of the inhibitory effect of protein on the biologic activity of polyphenols. The inhibitory mechanism of the food protein lactoferrin on the antibacterial activity of oligomeric ellagitannin oenothein B (OeB) was investigated using fluorescence quenching, isothermal titration calorimetry (ITC), circular dichroism (CD) measurement and molecular docking.

Results: The antibacterial activity of OeB against Staphylococcus aureus was inhibited by lactoferrin, which was retained at about 60%.