RESUMEN
Microbial drug resistance has become a serious problem of global concern, and the evolution and regulatory mechanisms of microbial drug resistance has become a hotspot of research in recent years. Recent studies showed that certain microbial resistance mechanisms are regulated by quorum sensing system. Quorum sensing is a ubiquitous cell-cell communication system in the microbial world, which associates with cell density. High-density microbial cells produce sufficient amount of small signal molecules, activating a range of downstream cellular processes including virulence and drug resistance mechanisms, which increases bacterial drug tolerance and causes infections on host organisms. In this review, the general mechanisms of microbial drug resistance and quorum-sensing systems are summarized with a focus on the association of quorum sensing and chemical signaling systems with microbial drug resistance mechanisms, including biofilm formation and drug efflux pump. The potential use of quorum quenching as a new strategy to control microbial resistance is also discussed.
Asunto(s)
Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Infecciones Bacterianas/microbiología , Farmacorresistencia Bacteriana , Percepción de Quorum , Animales , Bacterias/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Humanos , Percepción de Quorum/efectos de los fármacosRESUMEN
Dickeya zeae is a causal agent of rice root rot disease. The pathogen is known to produce a range of virulence factors, including phytotoxic zeamines and extracellular enzymes, but the mechanisms of virulence regulation remain vague. In this study, we identified a SlyA/MarR family transcription factor SlyA in D. zeae strain EC1. Disruption of slyA significantly decreased zeamine production, enhanced swimming and swarming motility, reduced biofilm formation and significantly decreased pathogenicity on rice. Quantitative polymerase chain reaction (qPCR) analysis confirmed the role of SlyA in transcriptional modulation of a range of genes associated with bacterial virulence. In trans expression of slyA in expI mutants recovered the phenotypes of motility and biofilm formation, suggesting that SlyA is downstream of the acylhomoserine lactone-mediated quorum sensing pathway. Taken together, the findings from this study unveil a key transcriptional regulatory factor involved in the modulation of virulence factor production and overall pathogenicity of D. zeae EC1.