Comparative NanoUPLC-MSE analysis between magainin I-susceptible and -resistant Escherichia coli strains

Abstract

In recent years the antimicrobial peptides (AMPs) have been prospected and designed as new alternatives to conventional antibiotics. Indeed, AMPs have presented great potential toward pathogenic bacterial strains by means of complex mechanisms of action. However, reports have increasingly emerged regarding the mechanisms by which bacteria resist AMP administration. In this context, we performed a comparative proteomic study by using the total bacterial lysate of magainin I-susceptible and –resistant E. coli strains. After nanoUPLC-MSE analyses we identified 742 proteins distributed among the experimental groups, and 25 proteins were differentially expressed in the resistant strains. Among them 10 proteins involved in bacterial resistance, homeostasis, nutrition and protein transport were upregulated, while 15 proteins related to bacterial surface modifications, genetic information and β-lactams binding-protein were downregulated. Moreover, 60 exclusive proteins were identified in the resistant strains, among which biofilm and cell wall formation and multidrug efflux pump proteins could be observed. Thus, differentially from previous studies that could only associate single proteins to AMP bacterial resistance, data here reported show that several metabolic pathways may be related to E. coli resistance to AMPs, revealing the crucial role of multiple “omics” studies in order to elucidate the global molecular mechanisms involved in this resistance.

Biophysical Investigations Elucidating the Mechanisms of Action of Antimicrobial Peptides and Their Synergism

“…By also modulating the immune response of the host organisms, their efficiency is considerably enhanced, and because of this extension of functionalities, it has been suggested to rename them as ‘host defense peptides’ [ 47 , 48 , 49 , 50 ]. Indeed, metabolomics studies reveal complex reactions by the bacterial cells when exposed to AMPs, many being unique to a specific sequence [ 51 , 52 ].…”

Recent advancements in microfluidic chip biosensor detection of foodborne pathogenic bacteria: a review

“…Magainin I is a naturally occurring polypeptide on the skin of African Rana unguiculata, which has antimicrobial and antiparasitic activities and can selectively bind to E. coli O157:H7. Furthermore, this peptide can semi-selectively bind to the cell surface of Gram-negative bacteria [ 44 ]. Thuy et al [ 45 ] combined a Magainin I microfluidic platform with a recombinase polymerase amplification (RPA) sensor for the detection of low pathogenic bacteria levels in complex samples.…”

Non-Lytic Antibacterial Peptides That Translocate Through Bacterial Membranes to Act on Intracellular Targets

“…Although AMPs can rapidly display their actions on bacterial membranes, an increasing number of reports have highlighted that bacteria can easily evade membrane-associated mechanisms by adapting the constitution and proportion of phospholipids in their OM and IM [113], as reported for E. coli strains resistant to magainin [114]. Therefore, non-lytic AMPs have been pinpointed for their ability to inactivate bacteria by interrupting vital cellular process, instead of membrane destabilization and disruption.…”