Next Issue
Previous Issue

Table of Contents

Antibiotics, Volume 3, Issue 4 (December 2014) , Pages 461-713

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
View options order results:
result details:
Displaying articles 1-13
Export citation of selected articles as:
Open AccessArticle Structure-Dependent Immune Modulatory Activity of Protegrin-1 Analogs
Antibiotics 2014, 3(4), 694-713; https://doi.org/10.3390/antibiotics3040694
Received: 12 September 2014 / Revised: 31 October 2014 / Accepted: 13 November 2014 / Published: 27 November 2014
Cited by 2 | Viewed by 3202 | PDF Full-text (2293 KB) | HTML Full-text | XML Full-text
Abstract
Protegrins are porcine antimicrobial peptides (AMPs) that belong to the cathelicidin family of host defense peptides. Protegrin-1 (PG-1), the most investigated member of the protegrin family, is an arginine-rich peptide consisting of 18 amino acid residues, its main chain adopting a β-hairpin structure [...] Read more.
Protegrins are porcine antimicrobial peptides (AMPs) that belong to the cathelicidin family of host defense peptides. Protegrin-1 (PG-1), the most investigated member of the protegrin family, is an arginine-rich peptide consisting of 18 amino acid residues, its main chain adopting a β-hairpin structure that is linked by two disulfide bridges. We report on the immune modulatory activity of PG-1 and its analogs in neutralizing bacterial endotoxin and capsular polysaccharides, consequently inhibiting inflammatory mediators’ release from macrophages. We demonstrate that the β-hairpin structure motif stabilized with at least one disulfide bridge is a prerequisite for the immune modulatory activity of this type of AMP. Full article
(This article belongs to the Special Issue Antimicrobial Peptides) Printed Edition available
Figures

Graphical abstract

Open AccessReview The Role of Cationic Polypeptides in Modulating HIV-1 Infection of the Cervicovaginal Mucosa
Antibiotics 2014, 3(4), 677-693; https://doi.org/10.3390/antibiotics3040677
Received: 3 September 2014 / Revised: 17 September 2014 / Accepted: 13 November 2014 / Published: 26 November 2014
Cited by 2 | Viewed by 2895 | PDF Full-text (591 KB) | HTML Full-text | XML Full-text
Abstract
The mucosa and overlying fluid of the female reproductive tract (FRT) are portals for the heterosexual transmission of HIV-1. Toward the ongoing development of topically applied microbicides and mucosal vaccines against HIV-1, it is evermore important to understand how the dynamic FRT mucosa [...] Read more.
The mucosa and overlying fluid of the female reproductive tract (FRT) are portals for the heterosexual transmission of HIV-1. Toward the ongoing development of topically applied microbicides and mucosal vaccines against HIV-1, it is evermore important to understand how the dynamic FRT mucosa is involved in controlling transmission and infection of HIV-1. Cationic peptides and proteins are the principal innate immune effector molecules of mucosal surfaces, and interact in a combinatorial fashion to modulate HIV-1 infection of the cervix and vagina. While cationic peptides and proteins have historically been categorized as antimicrobial or have other host-benefitting roles, an increasing number of these molecules have been found to augment HIV-1 infection and potentially antagonize host defense. Complex environmental factors such as hormonal fluctuations and/or bacterial and viral co-infections provide additional challenges to both experimentation and interpretation of results. In the context of heterosexual transmission of HIV-1, this review explores how various cationic peptides and proteins participate in modulating host defense against HIV-1 of the cervicovaginal mucosa. Full article
(This article belongs to the Special Issue Antimicrobial Peptides) Printed Edition available
Figures

Figure 1

Open AccessReview Host Antimicrobial Peptides in Bacterial Homeostasis and Pathogenesis of Disease
Antibiotics 2014, 3(4), 645-676; https://doi.org/10.3390/antibiotics3040645
Received: 29 September 2014 / Revised: 5 November 2014 / Accepted: 5 November 2014 / Published: 17 November 2014
Cited by 8 | Viewed by 3605 | PDF Full-text (1294 KB) | HTML Full-text | XML Full-text
Abstract
Innate immune responses function as a first line of host defense against the development of bacterial infection, and in some cases to preserve the sterility of privileged sites in the human host. Bacteria that enter these sites must counter host responses for colonization. [...] Read more.
Innate immune responses function as a first line of host defense against the development of bacterial infection, and in some cases to preserve the sterility of privileged sites in the human host. Bacteria that enter these sites must counter host responses for colonization. From the host’s perspective, the innate immune system works expeditiously to minimize the bacterial threat before colonization and subsequent dysbiosis. The multifactorial nature of disease further challenges predictions of how each independent variable influences bacterial pathogenesis. From bacterial colonization to infection and through disease, the microenvironments of the host are in constant flux as bacterial and host factors contribute to changes at the host-pathogen interface, with the host attempting to eradicate bacteria and the bacteria fighting to maintain residency. A key component of this innate host response towards bacterial infection is the production of antimicrobial peptides (AMPs). As an early component of the host response, AMPs modulate bacterial load and prevent establishment of infection. Under quiescent conditions, some AMPs are constitutively expressed by the epithelium. Bacterial infection can subsequently induce production of other AMPs in an effort to maintain sterility, or to restrict colonization. As demonstrated in various studies, the absence of a single AMP can influence pathogenesis, highlighting the importance of AMP concentration in maintaining homeostasis. Yet, AMPs can increase bacterial virulence through the co-opting of the peptides or alteration of bacterial virulence gene expression. Further, bacterial factors used to subvert AMPs can modify host microenvironments and alter colonization of the residential flora that principally maintain homeostasis. Thus, the dynamic interplay between host defense peptides and bacterial factors produced to quell peptide activity play a critical role in the progression and outcome of disease. Full article
(This article belongs to the Special Issue Antimicrobial Peptides) Printed Edition available
Figures

Figure 1

Open AccessArticle Patient Attitudes and Beliefs and Provider Practices Regarding Antibiotic Use for Acute Respiratory Tract Infections in Minya, Egypt
Antibiotics 2014, 3(4), 632-644; https://doi.org/10.3390/antibiotics3040632
Received: 17 September 2014 / Revised: 24 October 2014 / Accepted: 24 October 2014 / Published: 14 November 2014
Cited by 3 | Viewed by 3556 | PDF Full-text (603 KB) | HTML Full-text | XML Full-text
Abstract
The inappropriate use of antibiotics in the community is one of the major causes of antimicrobial resistance. This study aimed to explore the physician prescribing pattern of antibiotics for acute respiratory infections (ARIs) and to explore the knowledge, attitudes, and practices of patients [...] Read more.
The inappropriate use of antibiotics in the community is one of the major causes of antimicrobial resistance. This study aimed to explore the physician prescribing pattern of antibiotics for acute respiratory infections (ARIs) and to explore the knowledge, attitudes, and practices of patients regarding antibiotic use for ARIs. The study was conducted in Upper Egypt and used quantitative and qualitative research techniques. Eligible patients exiting outpatient clinics with ARIs were invited to participate in the study. A qualitative study was conducted through 20 focus group discussions. Out of 350 encounters for patients with various ARIs, 292 (83%) had been prescribed at least one antibiotic. Factors significantly associated with antibiotic prescribing for adults included patient preference that an antibiotic be prescribed. For children younger than 18, presentation with fever, cough, loss of appetite, and sore throat, along with the caregiver’s antibiotic preference, were associated with an antibiotic prescription. Several misconceptions regarding antibiotic use among community members were stated, such as the strong belief of the curing and prophylactic power of antibiotics for the common cold. Interventions to promote proper antibiotic use for ARIs need to be piloted, targeting both physicians and the public. Educational programs for physicians and campaigns to raise public awareness regarding proper antibiotic use for ARIs need to be developed. Full article
Open AccessArticle Killing of Staphylococci by θ-Defensins Involves Membrane Impairment and Activation of Autolytic Enzymes
Antibiotics 2014, 3(4), 617-631; https://doi.org/10.3390/antibiotics3040617
Received: 23 September 2014 / Revised: 30 October 2014 / Accepted: 31 October 2014 / Published: 14 November 2014
Cited by 12 | Viewed by 3065 | PDF Full-text (4326 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
θ-Defensins are cyclic antimicrobial peptides expressed in leukocytes of Old world monkeys. To get insight into their antibacterial mode of action, we studied the activity of RTDs (rhesus macaque θ-defensins) against staphylococci. We found that in contrast to other defensins, RTDs do not [...] Read more.
θ-Defensins are cyclic antimicrobial peptides expressed in leukocytes of Old world monkeys. To get insight into their antibacterial mode of action, we studied the activity of RTDs (rhesus macaque θ-defensins) against staphylococci. We found that in contrast to other defensins, RTDs do not interfere with peptidoglycan biosynthesis, but rather induce bacterial lysis in staphylococci by interaction with the bacterial membrane and/or release of cell wall lytic enzymes. Potassium efflux experiments and membrane potential measurements revealed that the membrane impairment by RTDs strongly depends on the energization of the membrane. In addition, RTD treatment caused the release of Atl-derived cell wall lytic enzymes probably by interaction with membrane-bound lipoteichoic acid. Thus, the premature and uncontrolled activity of these enzymes contributes strongly to the overall killing by θ-defensins. Interestingly, a similar mode of action has been described for Pep5, an antimicrobial peptide of bacterial origin. Full article
(This article belongs to the Special Issue Antimicrobial Peptides) Printed Edition available
Figures

Figure 1

Open AccessArticle Position-Dependent Influence of the Three Trp Residues on the Membrane Activity of the Antimicrobial Peptide, Tritrpticin
Antibiotics 2014, 3(4), 595-616; https://doi.org/10.3390/antibiotics3040595
Received: 15 September 2014 / Revised: 23 October 2014 / Accepted: 23 October 2014 / Published: 6 November 2014
Cited by 3 | Viewed by 2798 | PDF Full-text (4442 KB) | HTML Full-text | XML Full-text
Abstract
Antimicrobial peptides (AMPs) constitute promising candidates for the development of new antibiotics. Among the ever-expanding family of AMPs, tritrpticin has strong antimicrobial activity against a broad range of pathogens. This 13-residue peptide has an unusual amino acid sequence that is almost symmetrical and [...] Read more.
Antimicrobial peptides (AMPs) constitute promising candidates for the development of new antibiotics. Among the ever-expanding family of AMPs, tritrpticin has strong antimicrobial activity against a broad range of pathogens. This 13-residue peptide has an unusual amino acid sequence that is almost symmetrical and features three central Trp residues with two Arg residues near each end of the peptide. In this work, the role of the three sequential Trp residues in tritrpticin was studied in a systematic fashion by making a series of synthetic peptides with single-, double- and triple-Trp substitutions to Tyr or Ala. 1H NMR and fluorescence spectroscopy demonstrated the ability of all of the tritrpticin-analog peptides to interact with negatively-charged membranes. Consequently, most tritrpticin analogs exhibited the ability to permeabilize synthetic ePC:ePG (egg-yolk phosphatidylcholine (ePC), egg-yolk phosphatidylglycerol (ePG)) vesicles and live Escherichia coli bacteria. The membrane perturbation characteristics were highly dependent on the location of the Trp residue substitution, with Trp6 being the most important residue and Trp8 the least. The membrane permeabilization activity of the peptides in synthetic and biological membranes was directly correlated with the antimicrobial potency of the peptides against E. coli. These results contribute to the understanding of the role of each of the three Trp residues to the antimicrobial activity of tritrpticin. Full article
(This article belongs to the Special Issue Antimicrobial Peptides) Printed Edition available
Figures

Figure 1

Open AccessReview Old and New Glycopeptide Antibiotics: Action and Resistance
Antibiotics 2014, 3(4), 572-594; https://doi.org/10.3390/antibiotics3040572
Received: 28 July 2014 / Revised: 20 October 2014 / Accepted: 23 October 2014 / Published: 4 November 2014
Cited by 22 | Viewed by 7572 | PDF Full-text (820 KB) | HTML Full-text | XML Full-text
Abstract
Glycopeptides are considered antibiotics of last resort for the treatment of life-threatening infections caused by relevant Gram-positive human pathogens, such as Staphylococcus aureus, Enterococcus spp. and Clostridium difficile. The emergence of glycopeptide-resistant clinical isolates, first among enterococci and then in staphylococci, [...] Read more.
Glycopeptides are considered antibiotics of last resort for the treatment of life-threatening infections caused by relevant Gram-positive human pathogens, such as Staphylococcus aureus, Enterococcus spp. and Clostridium difficile. The emergence of glycopeptide-resistant clinical isolates, first among enterococci and then in staphylococci, has prompted research for second generation glycopeptides and a flurry of activity aimed at understanding resistance mechanisms and their evolution. Glycopeptides are glycosylated non-ribosomal peptides produced by a diverse group of soil actinomycetes. They target Gram-positive bacteria by binding to the acyl-D-alanyl-D-alanine (D-Ala-D-Ala) terminus of the growing peptidoglycan on the outer surface of the cytoplasmatic membrane. Glycopeptide-resistant organisms avoid such a fate by replacing the D-Ala-D-Ala terminus with D-alanyl-D-lactate (D-Ala-D-Lac) or D-alanyl-D-serine (D-Ala-D-Ser), thus markedly reducing antibiotic affinity for the cellular target. Resistance has manifested itself in enterococci and staphylococci largely through the expression of genes (named van) encoding proteins that reprogram cell wall biosynthesis and, thus, evade the action of the antibiotic. These resistance mechanisms were most likely co-opted from the glycopeptide producing actinomycetes, which use them to avoid suicide during antibiotic production, rather than being orchestrated by pathogen bacteria upon continued treatment. van-like gene clusters, similar to those described in enterococci, were in fact identified in many glycopeptide-producing actinomycetes, such as Actinoplanes teichomyceticus, which produces teicoplanin, and Streptomyces toyocaensis, which produces the A47934 glycopeptide. In this paper, we describe the natural and semi-synthetic glycopeptide antibiotics currently used as last resort drugs for Gram-positive infections and compare the van gene-based strategies of glycopeptide resistance among the pathogens and the producing actinomycetes. Particular attention is given to the strategy of immunity recently described in Nonomuraea sp. ATCC 39727. Nonomuraea sp. ATCC 39727 is the producer of A40926, which is the natural precursor of the second generation semi-synthetic glycopeptide dalbavancin, very recently approved for acute bacterial skin and skin structure infections. A thorough understanding of glycopeptide immunity in this producing microorganism may be particularly relevant to predict and eventually control the evolution of resistance that might arise following introduction of dalbavancin and other second generation glycopeptides into clinics. Full article
(This article belongs to the Special Issue Mechanisms of Antibiotic Resistance)
Figures

Figure 1

Open AccessShort Note Occurrence of Ionophores in the Danish Environment
Antibiotics 2014, 3(4), 564-571; https://doi.org/10.3390/antibiotics3040564
Received: 12 June 2014 / Revised: 11 October 2014 / Accepted: 15 October 2014 / Published: 4 November 2014
Cited by 2 | Viewed by 2387 | PDF Full-text (696 KB) | HTML Full-text | XML Full-text
Abstract
Antibiotics in the environment are a potential threat to environmental ecosystems as well as human health and safety. Antibiotics are designed to have a biological effect at low doses, and the low levels detected in the environment have turned focus on the need [...] Read more.
Antibiotics in the environment are a potential threat to environmental ecosystems as well as human health and safety. Antibiotics are designed to have a biological effect at low doses, and the low levels detected in the environment have turned focus on the need for more research on environmental occurrence and fate, to assess the risk and requirement for future regulation. This article describes the first occurrence study of the antibiotic polyether ionophores (lasalocid, monensin, narasin, and salinomycin) in the Danish environment. Various environmental matrices (river water, sediment, and soil) have been evaluated during two different sampling campaigns carried out in July 2011 and October 2012 in an agricultural area of Zealand, Denmark. Lasalocid was not detected in any of the samples. Monensin was measured at a concentration up to 20 ng·L−1 in river water and 13 µg·kg−1 dry weight in the sediment as well as being the most frequently detected ionophore in the soil samples with concentrations up to 8 µg·kg−1 dry weight. Narasin was measured in sediment samples at 2 µg·kg−1 dry weight and in soil between 1 and 18 µg·kg−1 dry weight. Salinomycin was detected in a single soil sample at a concentration of 30 µg·kg−1 dry weight. Full article
Figures

Figure 1

Open AccessReview Resistance to Antimicrobial Peptides in Vibrios
Antibiotics 2014, 3(4), 540-563; https://doi.org/10.3390/antibiotics3040540
Received: 16 September 2014 / Revised: 25 September 2014 / Accepted: 8 October 2014 / Published: 27 October 2014
Cited by 5 | Viewed by 3116 | PDF Full-text (832 KB) | HTML Full-text | XML Full-text
Abstract
Vibrios are associated with a broad diversity of hosts that produce antimicrobial peptides (AMPs) as part of their defense against microbial infections. In particular, vibrios colonize epithelia, which function as protective barriers and express AMPs as a first line of chemical defense against [...] Read more.
Vibrios are associated with a broad diversity of hosts that produce antimicrobial peptides (AMPs) as part of their defense against microbial infections. In particular, vibrios colonize epithelia, which function as protective barriers and express AMPs as a first line of chemical defense against pathogens. Recent studies have shown they can also colonize phagocytes, key components of the animal immune system. Phagocytes infiltrate infected tissues and use AMPs to kill the phagocytosed microorganisms intracellularly, or deliver their antimicrobial content extracellularly to circumvent tissue infection. We review here the mechanisms by which vibrios have evolved the capacity to evade or resist the potent antimicrobial defenses of the immune cells or tissues they colonize. Among their strategies to resist killing by AMPs, primarily vibrios use membrane remodeling mechanisms. In particular, some highly resistant strains substitute hexaacylated Lipid A with a diglycine residue to reduce their negative surface charge, thereby lowering their electrostatic interactions with cationic AMPs. As a response to envelope stress, which can be induced by membrane-active agents including AMPs, vibrios also release outer membrane vesicles to create a protective membranous shield that traps extracellular AMPs and prevents interaction of the peptides with their own membranes. Finally, once AMPs have breached the bacterial membrane barriers, vibrios use RND efflux pumps, similar to those of other species, to transport AMPs out of their cytoplasmic space. Full article
(This article belongs to the Special Issue Antimicrobial Peptides) Printed Edition available
Figures

Figure 1

Open AccessArticle Antimicrobial Activity of Chemokine CXCL10 for Dermal and Oral Microorganisms
Antibiotics 2014, 3(4), 527-539; https://doi.org/10.3390/antibiotics3040527
Received: 4 September 2014 / Revised: 3 October 2014 / Accepted: 14 October 2014 / Published: 23 October 2014
Cited by 6 | Viewed by 2864 | PDF Full-text (587 KB) | HTML Full-text | XML Full-text
Abstract
CXCL10 (IP-10) is a small 10 kDa chemokine with antimicrobial activity. It is induced by IFN-γ, chemoattracts mononuclear cells, and promotes adhesion of T cells. Recently, we detected CXCL10 on the surface of the skin and in the oral cavity. In the current [...] Read more.
CXCL10 (IP-10) is a small 10 kDa chemokine with antimicrobial activity. It is induced by IFN-γ, chemoattracts mononuclear cells, and promotes adhesion of T cells. Recently, we detected CXCL10 on the surface of the skin and in the oral cavity. In the current study, we used broth microdilution and radial diffusion assays to show that CXCL10 inhibits the growth of Escherichia coli, Staphylococcus aureus, Corynebacterium jeikeium, Corynebacterium striatum, and Candida albicans HMV4C, but not Corynebacterium bovis, Streptococcus mutans, Streptococcus mitis, Streptococcus sanguinis, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Poryphromonas gingivalis, or C. albicans ATCC 64124. The reason for the selective antimicrobial activity is not yet known. However, antimicrobial activity of CXCL10 may be related to its composition and structure, as a cationic 98 amino acid residue molecule with 10 lysine residues, 7 arginine residues, a total net charge of +11, and a theoretical pI of 9.93. Modeling studies revealed that CXCL10 contains an α-helix at the N-terminal, three anti-parallel β-strands in the middle, and an α-helix at the C-terminal. Thus, CXCL10, when produced on the surface of the skin or in the oral cavity, likely has antimicrobial activity and may enhance innate antimicrobial and cellular responses to the presence of select commensal or opportunistic microorganisms. Full article
(This article belongs to the Special Issue Antimicrobial Peptides) Printed Edition available
Figures

Figure 1

Open AccessArticle Anti-Biofilm and Immunomodulatory Activities of Peptides That Inhibit Biofilms Formed by Pathogens Isolated from Cystic Fibrosis Patients
Antibiotics 2014, 3(4), 509-526; https://doi.org/10.3390/antibiotics3040509
Received: 18 August 2014 / Revised: 8 October 2014 / Accepted: 14 October 2014 / Published: 20 October 2014
Cited by 16 | Viewed by 3521 | PDF Full-text (1149 KB) | HTML Full-text | XML Full-text
Abstract
Cystic fibrosis (CF) patients often acquire chronic respiratory tract infections due to Pseudomonas aeruginosa and Burkholderia cepacia complex (Bcc) species. In the CF lung, these bacteria grow as multicellular aggregates termed biofilms. Biofilms demonstrate increased (adaptive) resistance to conventional antibiotics, and there are [...] Read more.
Cystic fibrosis (CF) patients often acquire chronic respiratory tract infections due to Pseudomonas aeruginosa and Burkholderia cepacia complex (Bcc) species. In the CF lung, these bacteria grow as multicellular aggregates termed biofilms. Biofilms demonstrate increased (adaptive) resistance to conventional antibiotics, and there are currently no available biofilm-specific therapies. Using plastic adherent, hydroxyapatite and flow cell biofilm models coupled with confocal and scanning electron microscopy, it was demonstrated that an anti-biofilm peptide 1018 prevented biofilm formation, eradicated mature biofilms and killed biofilms formed by a wide range of P. aeruginosa and B. cenocepacia clinical isolates. New peptide derivatives were designed that, compared to their parent peptide 1018, showed similar or decreased anti-biofilm activity against P. aeruginosa biofilms, but increased activity against biofilms formed by the Gram-positive bacterium methicillin resistant Staphylococcus aureus. In addition, some of these new peptide derivatives retained the immunomodulatory activity of 1018 since they induced the production of the chemokine monocyte chemotactic protein-1 (MCP-1) and suppressed lipopolysaccharide-mediated tumor necrosis factor-α (TNF-α) production by human peripheral blood mononuclear cells (PBMC) and were non-toxic towards these cells. Peptide 1018 and its derivatives provide promising leads for the treatment of chronic biofilm infections and hyperinflammatory lung disease in CF patients. Full article
(This article belongs to the Special Issue Antimicrobial Peptides) Printed Edition available
Open AccessArticle Differential Susceptibility of Bacteria to Mouse Paneth Cell a-Defensins under Anaerobic Conditions
Antibiotics 2014, 3(4), 493-508; https://doi.org/10.3390/antibiotics3040493
Received: 9 September 2014 / Revised: 28 September 2014 / Accepted: 8 October 2014 / Published: 17 October 2014
Cited by 1 | Viewed by 3081 | PDF Full-text (753 KB) | HTML Full-text | XML Full-text
Abstract
Small intestinal Paneth cells secrete a-defensin peptides, termed cryptdins (Crps) in mice, into the intestinal lumen, where they confer immunity to oral infections and define the composition of the ileal microbiota. In these studies, facultative bacteria maintained under aerobic or anaerobic conditions displayed [...] Read more.
Small intestinal Paneth cells secrete a-defensin peptides, termed cryptdins (Crps) in mice, into the intestinal lumen, where they confer immunity to oral infections and define the composition of the ileal microbiota. In these studies, facultative bacteria maintained under aerobic or anaerobic conditions displayed differential sensitivities to mouse a-defensins under in vitro assay conditions. Regardless of oxygenation, Crps 2 and 3 had robust and similar bactericidal activities against S. typhimurium and S. flexneri, but Crp4 activity against S. flexneri was attenuated in the absence of oxygen. Anaerobic bacteria varied in their susceptibility to Crps 2-4, with Crp4 showing less activity than Crps 2 and 3 against Enterococcus faecalis, and Bacteroides fragilis in anaerobic assays, but Fusobacterium necrophorum was killed only by Crp4 and not by Crps 2 and 3. The influence of anaerobiosis in modulating Crp bactericidal activities in vitro suggests that a-defensin effects on the enteric microbiota may be subject to regulation by local oxygen tension. Full article
(This article belongs to the Special Issue Antimicrobial Peptides) Printed Edition available
Open AccessReview Antimicrobial Peptide Resistance Mechanisms of Gram-Positive Bacteria
Antibiotics 2014, 3(4), 461-492; https://doi.org/10.3390/antibiotics3040461
Received: 28 August 2014 / Revised: 25 September 2014 / Accepted: 28 September 2014 / Published: 13 October 2014
Cited by 42 | Viewed by 5355 | PDF Full-text (996 KB) | HTML Full-text | XML Full-text
Abstract
Antimicrobial peptides, or AMPs, play a significant role in many environments as a tool to remove competing organisms. In response, many bacteria have evolved mechanisms to resist these peptides and prevent AMP-mediated killing. The development of AMP resistance mechanisms is driven by direct [...] Read more.
Antimicrobial peptides, or AMPs, play a significant role in many environments as a tool to remove competing organisms. In response, many bacteria have evolved mechanisms to resist these peptides and prevent AMP-mediated killing. The development of AMP resistance mechanisms is driven by direct competition between bacterial species, as well as host and pathogen interactions. Akin to the number of different AMPs found in nature, resistance mechanisms that have evolved are just as varied and may confer broad-range resistance or specific resistance to AMPs. Specific mechanisms of AMP resistance prevent AMP-mediated killing against a single type of AMP, while broad resistance mechanisms often lead to a global change in the bacterial cell surface and protect the bacterium from a large group of AMPs that have similar characteristics. AMP resistance mechanisms can be found in many species of bacteria and can provide a competitive edge against other bacterial species or a host immune response. Gram-positive bacteria are one of the largest AMP producing groups, but characterization of Gram-positive AMP resistance mechanisms lags behind that of Gram-negative species. In this review we present a summary of the AMP resistance mechanisms that have been identified and characterized in Gram-positive bacteria. Understanding the mechanisms of AMP resistance in Gram-positive species can provide guidelines in developing and applying AMPs as therapeutics, and offer insight into the role of resistance in bacterial pathogenesis. Full article
(This article belongs to the Special Issue Antimicrobial Peptides) Printed Edition available
Antibiotics EISSN 2079-6382 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top