ABSTRACT Cronobacter sakazakii , an opportunistic foodborne pathogen, primarily with the infections that can cause bacteremia, necrotizing enterocolitis, and neonatal meningitis. These pathogens are Gram‐negative rods, motile with peritrichous flagella without spore‐forming capability, can grow under aerobic and anaerobic conditions, and tolerance to acidic conditions and desiccations stress. Phenyllactic acid (PLA), a phenolic acid with broad‐spectrum antibacterial activity, is a promising natural preservative. However, its effects on C. sakazakii biofilms remain unclear. This study evaluated the antibiofilm potential of PLA, a natural antimicrobial metabolite, against C. sakazakii and investigated its effects on cell membrane integrity. First, the minimum inhibitory concentration (MIC) of PLA was assessed at 4 mg/mL. The MIC (4 mg/mL) of PLA was observed to reduce C. sakazakii for planktonic cells and biofilm formation on food‐contact surfaces (stainless steel, silicon rubber, and polyvinyl chloride) by about 3 log CFU/cm 2 , respectively. PLA at 4 mg/mL significantly altered ALP activity, intracellular and extracellular ATP, suggested membrane disruption, cell integrity, and leakage of intracellular components. Fourier‐transform infrared spectroscopy (FTIR) analysis provided extracellular polymeric substances composition. As confirmed by confocal laser scanning microscopy and scanning electron microscopy revealed disrupted biofilm architecture and altered cell morphology. Mechanistic analyses demonstrated that PLA exposure increased membrane permeability, indicated by elevated extracellular ATP and protein leakage, while intracellular ATP levels decreased. All things considered, these results clarify PLA's effectiveness against biofilm of C. sakazakii . These results demonstrate that PLA inhibits C. sakazakii biofilm formation primarily by disrupting membrane integrity, suggesting its potential as a natural antimicrobial strategy for controlling biofilms and supports the potential application of PLA as an effective antimicrobial agent in food industry to enhancing food safety.
Rapak et al. (Thu,) studied this question.