Deciphering the antibacterial mechanism of monocaprin against methicillin-resistant Staphylococcus aureus by integrated transcriptomic and metabolomic analyses and its application in pork preservation

Methicillin-resistant Staphylococcus aureus (MRSA) is a drug-resistant pathogen generally derived from pork and other animal foods. This study investigated the antibacterial mechanism of monocaprin against MRSA and its preservation effect on pork. The results showed that monocaprin had a strong anti-MRSA activity with visible cell surface damage and a minimum inhibitory concentration of 0.16 mg/mL. The transcriptomic and metabolomic analyses showed that 255 genes, 45 metabolites in positive ion mode, and 50 in negative ion mode were significantly changed after monocaprin treatment (0.08 mg/mL). The integrative analysis of omics suggested that monocaprin led to osmotic imbalance, amino acid metabolism inhibition, energy metabolism disorder and aerobic respiration obstruction of MRSA. Sublethally damaged MRSA required increased specific protein synthesis and pyrimidine metabolism, enhanced glycolysis, activation of anaerobic respiration, and promotion of biofilm formation for survival under monocaprin stress. Moreover, monocaprin obviously restrained the growth of MRSA in pork, delayed the spoilage of pork during storage at 4 °C for 8 days, and had no adverse effects on its sensory properties. Overall, these results revealed the anti-MRSA mechanism of monocaprin and suggested that monocaprin can be used to control MRSA in pork.