Investigating The Antimicrobial Activity And Mechanism Of Garlic-Derived Organosulfur Compounds To Cronobacter Sakazakji

Cronobacter sakazakii, a leading pathogen associated with invasive infection of infants causing meningitis, necrotizing entercolitis and bacteraemia. The prevention for the infection of C. sakazakii is particularly important. Two garlic-derived organosulfur compounds decomposed from unstable thiosulfinates (i.e., ajoene and diallyl sulfide) were found to be highly effective antimicrobial compounds against Findings from this study can aid in the development of more effective intervention strategies to reduce the risk of C. sakazakii contamination in the food supply, specifically in dehydrated products consumed by susceptible populations.We present the first study using high-throughput whole transcriptome sequencing (RNA-seq) and vibrational spectroscopy to characterize and fingerprint the pathogenic bacteria injury under unfavorable stress on both genotypic and phenotypic levels and link the correlation. RNA-seq shows changes in gene expression patterns and transcriptomic response resulting from this chemical stress while confocal micro-Raman spectroscopy characterizes macromolecular changes in the bacterial cell resulting from cell injury. RNA-seq analyses showed that the bacterial response to ajoene differed from diallyl sulfide. Specifically ajoene caused down regulation of motility related genes, while diallyl sulfide treatment caused an increased expression of cell wall synthesis genes. Confocal micro-Raman spectroscopy revealed that both ajoene and diallyl sulfide appear to have the same phase I antimicrobial mechanism of binding to thiol-containing proteins/enzymes in bacterial cells generating a disulfide stretching band, but a different phase II showing alterations in the secondary structures of proteins in two different ways. Diallyl sulfide primarily altered the a-helix and β-sheet as reflected in changes in the amide I (band at1638cm-1) while ajoene altered the structures containing phenylalanine and tyrosine (band at1605cm-1). Bayesian probability validated the ability of unsupervised chemometric models [principal component analysis (PCA)] to differentiate treated and control C. sakazakii cells. Scanning electron microscopy (SEM) confirmed cell injury showing significant morphological variations in bacterial cells following treatments by these two organosulfur compounds.