Efficacy of six frog skin-derived antimicrobial peptides against colistin-resistant strains of the Acinetobacter baumannii group

2012 ◽  
Vol 39 (4) ◽  
pp. 317-320 ◽  
Author(s):  
J. Michael Conlon ◽  
Agnes Sonnevend ◽  
Tibor Pál ◽  
Xavier Vila-Farrés
Keyword(s):  
Antimicrobial Peptides ◽  
Acinetobacter Baumannii ◽  
Frog Skin ◽  
Resistant Strains

Antimicrobial Peptides and their Multiple Effects at Sub-Inhibitory Concentrations

2020 ◽  
Vol 20 (14) ◽  
pp. 1264-1273 ◽  
Author(s):  
Bruno Casciaro ◽  
Floriana Cappiello ◽  
Walter Verrusio ◽  
Mauro Cacciafesta ◽  
Maria Luisa Mangoni
Keyword(s):  
Antimicrobial Peptides ◽  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
Mechanisms Of Action ◽  
New Drugs ◽  
Lead Compounds ◽  
Bacterial Pathogenicity ◽  
Growth Inhibitory ◽  
Resistant Strains ◽  
Conventional Antibiotics

The frequent occurrence of multidrug-resistant strains to conventional antimicrobials has led to a clear decline in antibiotic therapies. Therefore, new molecules with different mechanisms of action are extremely necessary. Due to their unique properties, antimicrobial peptides (AMPs) represent a valid alternative to conventional antibiotics and many of them have been characterized for their activity and cytotoxicity. However, the effects that these peptides cause at concentrations below the minimum growth inhibitory concentration (MIC) have yet to be fully analyzed along with the underlying molecular mechanism. In this mini-review, the ability of AMPs to synergize with different antibiotic classes or different natural compounds is examined. Furthermore, data on microbial resistance induction are reported to highlight the importance of antibiotic resistance in the fight against infections. Finally, the effects that sub-MIC levels of AMPs can have on the bacterial pathogenicity are summarized while showing how signaling pathways can be valid therapeutic targets for the treatment of infectious diseases. All these aspects support the high potential of AMPs as lead compounds for the development of new drugs with antibacterial and immunomodulatory activities.

scholarly journals Effect of antimicrobial peptides on colistin-susceptible and colistin-resistant strains ofKlebsiella pneumoniaeandEnterobacter asburiae

2015 ◽  
Vol 62 (4) ◽  
pp. 501-508 ◽  
Author(s):  
Béla Kádár ◽  
Béla Kocsis ◽  
Katalin Kristof ◽  
Ákos Tóth ◽  
Dóra Szabó
Keyword(s):  
Antimicrobial Peptides ◽  
Resistant Strains

scholarly journals Proteomics Landscape of Host-Pathogen Interaction in Acinetobacter baumannii Infected Mouse Lung

2021 ◽  
Vol 12 ◽  
Author(s):  
Xin Li ◽  
Xiaofen Liu ◽  
Peter Horvatovich ◽  
Yingwei Hu ◽  
Jing Zhang
Keyword(s):  
Immune Response ◽  
Antimicrobial Peptides ◽  
Acinetobacter Baumannii ◽  
Resistance Rate ◽  
Differentially Expressed ◽  
System Level ◽  
Mouse Lung ◽  
Differentially Expressed Proteins ◽  
Slow Development ◽  
Proteome Changes

Acinetobacter baumannii is an important pathogen of nosocomial infection worldwide, which can primarily cause pneumonia, bloodstream infection, and urinary tract infection. The increasing drug resistance rate of A. baumannii and the slow development of new antibacterial drugs brought great challenges for clinical treatment. Host immunity is crucial to the defense of A. baumannii infection, and understanding the mechanisms of immune response can facilitate the development of new therapeutic strategies. To characterize the system-level changes of host proteome in immune response, we used tandem mass tag (TMT) labeling quantitative proteomics to compare the proteome changes of lungs from A. baumannii infected mice with control mice 6 h after infection. A total of 6,218 proteins were identified in which 6,172 could be quantified. With threshold p < 0.05 and relative expression fold change > 1.2 or < 0.83, we found 120 differentially expressed proteins. Bioinformatics analysis showed that differentially expressed proteins after infection were associated with receptor recognition, NADPH oxidase (NOX) activation and antimicrobial peptides. These differentially expressed proteins were involved in the pathways including leukocyte transendothelial migration, phagocyte, neutrophil degranulation, and antimicrobial peptides. In conclusion, our study showed proteome changes in mouse lung tissue due to A. baumannii infection and suggested the important roles of NOX, neutrophils, and antimicrobial peptides in host response. Our results provide a potential list of protein candidates for the further study of host-bacteria interaction in A. baumannii infection. Data are available via ProteomeXchange with identifier PXD020640.

scholarly journals Antibacterial Peptides Resistance in Staphylococcus aureus: Various Mechanisms and the Association with Pathogenicity

Genes ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1527
Author(s):  
Miki Kawada-Matsuo ◽  
Mi Nguyen-Tra Le ◽  
Hitoshi Komatsuzawa
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Peptides ◽  
Antibacterial Peptides ◽  
Low Concentrations ◽  
Component Systems ◽  
Two Component Systems ◽  
Resistant Strains ◽  
Resistant Mutants ◽  
High Concentrations

Staphylococcus aureus is a bacterium that mainly colonizes the nasal cavity and skin. To colonize the host, it is necessary for S. aureus to resist many antibacterial factors derived from human and commensal bacteria. Among them are the bacteria-derived antimicrobial peptides (AMPs) called bacteriocins. It was reported that some two-component systems (TCSs), which are signal transduction systems specific to bacteria, are involved in the resistance to several bacteriocins in S. aureus. However, the TCS-mediated resistance is limited to relatively low concentrations of bacteriocins, while high concentrations of bacteriocins still exhibit antibacterial activity against S. aureus. To determine whether we could obtain highly bacteriocin-resistant mutants, we tried to isolate highly nisin A-resistant mutants by exposing the cells to sub-minimum inhibitory concentrations (MICs) of nisin A. Nisin A is one of the bacteriocins produced by Lactococcus lactis and is utilized as a food preservative worldwide. Finally, we obtained highly nisin A-resistant mutants with mutations in one TCS, BraRS, and in PmtR, which is involved in the expression of pmtABCD. Notably, some highly resistant strains also showed increased pathogenicity. Based on our findings, this review provides up-to-date information on the role of TCSs in the susceptibility to antibacterial peptides. Additionally, the mechanism for high antimicrobial peptides resistance and its association with pathogenicity in S. aureus is elucidated.

scholarly journals Low concentrations of commercial alcohol hand rubs facilitate growth of and secretion of extracellular proteins by multidrug-resistant strains of Acinetobacter baumannii

2007 ◽  
Vol 56 (12) ◽  
pp. 1595-1599 ◽  
Author(s):  
Justin Edwards ◽  
Geeta Patel ◽  
David W. Wareham
Keyword(s):  
Acinetobacter Baumannii ◽  
Culture Supernatant ◽  
Multidrug Resistant ◽  
Extracellular Proteins ◽  
Nosocomial Pathogen ◽  
Emulsifying Activity ◽  
Health Care Settings ◽  
Low Concentrations ◽  
Resistant Strains ◽  
Minimal Media

Acinetobacter baumannii is increasingly recognized as an important multidrug-resistant nosocomial pathogen. Recent work has highlighted enhanced growth and heightened virulence in the presence of ethyl alcohols. As alcohol-based hand rubs (ABHRs) are extensively used in health care settings, the authors set out to determine whether the hand rubs could also influence the growth of prevalent multidrug-resistant strains circulating in UK hospitals. A significant increase in growth was observed when minimal media were supplemented with concentrations of 1 % and lower of four commercially available hand rubs. In addition, growth in ABHR-supplemented media resulted in secretion of proteins into the culture supernatant. One of these was identified as OmpA, which is recognized as having emulsifying activity, which could potentially confer enhanced pathogenicity to A. baumannii.

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