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Verma AK, Ahmed SF, Hossain MS, Bhojiya AA, Mathur A, Upadhyay SK, Srivastava AK, Vishvakarma NK, Barik M, Rahaman MM, Bahadur NM. Molecular docking and simulation studies of flavonoid compounds against PBP-2a of methicillin-resistant Staphylococcus aureus. J Biomol Struct Dyn 2022; 40:10561-10577. [PMID: 34243699 DOI: 10.1080/07391102.2021.1944911] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Methicillin-Resistant Staphylococcus aureus (MRSA), a pathogenic bacterium that causes life-threatening outbreaks such as community-onset and nosocomial infections as emerging 'superbug'. Time and motion study of its virulent property developed resistance against most of the antibiotics such as Vancomycin. Thereby, to curb this problem entails the development of new therapeutic agents. Plant-derived antimicrobial agents have recently piqued people's interest, so in this research, 186 flavonoids compound selected to unmask the best candidates that can act as potent inhibitors against the Penicillin Binding Protein-2a (PBP-2a) of MRSA. Molecular docking performed using PyRx and GOLD suite to determine the binding affinities and interactions between the phytochemicals and the PBP-2a. The selected candidates strongly interact with the different amino acid residues. The 30 ns molecular dynamics (MD) simulations with five top-ranked compounds such as Naringin, Hesperidin, Neohesperidin, Didymin and Icariin validated the docking interactions. These findings are also strongly supported by root-mean-square deviation, root-mean-square fluctuation and the radius of gyration. ADME/T analysis demonstrates that these candidates appear to be safer inhibitors. Our findings point to natural flavonoids as a promising and readily available source of adjuvant antimicrobial therapy against resistant strains in the future.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Abhishek Kumar Verma
- Department of Life Sciences, Faculty of Science and Technology, Mewar University, Gangrar, Rajasthan, India
| | - Sk Faisal Ahmed
- Department of Biotechnology and Genetic Engineering, Noakhali Science and Technology University, Noakhali, Bangladesh
| | - Md Shahadat Hossain
- Department of Biotechnology and Genetic Engineering, Noakhali Science and Technology University, Noakhali, Bangladesh
| | - Ali Asger Bhojiya
- Faculty of Agriculture and Veterinary Sciences, Mewar University, Gangrar, Rajasthan, India
| | - Ankita Mathur
- Department of Life Sciences, Faculty of Science and Technology, Mewar University, Gangrar, Rajasthan, India
| | - Sudhir K Upadhyay
- Department of Environmental Sciences, V.B.S. Purvanchal University, Jaunpur, Uttar Pradesh, India
| | | | | | - Mayadhar Barik
- Department of Life Sciences, Faculty of Science and Technology, Mewar University, Gangrar, Rajasthan, India.,Research Section, Mewar University, Gangrar, Rajasthan, India
| | | | - Newaz Mohammed Bahadur
- Department of Applied Chemistry and Chemical Engineering, Noakhali Science and Technology University, Noakhali, Bangladesh
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Joodaki F, Martin LM, Greenfield ML. Generation and Computational Characterization of a Complex Staphylococcus aureus Lipid Bilayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:9481-9499. [PMID: 35901279 DOI: 10.1021/acs.langmuir.2c00483] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Studies indicate a crucial cell membrane role in the antibiotic resistance of Staphylococcus aureus. To simulate its membrane structure and dynamics, a complex molecular-scale computational representation of the S. aureus lipid bilayer was developed. Phospholipid types and their amounts were optimized by reverse Monte Carlo to represent characterization data from the literature, leading to 19 different phospholipid types that combine three headgroups [phosphatidylglycerol, lysyl-phosphatidylglycerol (LPG), and cardiolipin] and 10 tails, including iso- and anteiso-branched saturated chains. The averaged lipid bilayer thickness was 36.7 Å, and area per headgroup was 67.8 Å2. Phosphorus and nitrogen density profiles showed that LPG headgroups tended to be bent and oriented more parallel to the bilayer plane. The water density profile showed that small amounts reached the membrane center. Carbon density profiles indicated hydrophobic interactions for all lipids in the middle of the bilayer. Bond vector order parameters along each tail demonstrated different C-H ordering even within distinct lipids of the same type; however, all tails followed similar trends in average order parameter. These complex simulations further revealed bilayer insights beyond those attainable with monodisperse, unbranched lipids. Longer tails often extended into the opposite leaflet. Carbon at and beyond a branch showed significantly decreased ordering compared to carbon in unbranched tails; this feature arose in every branched lipid. Diverse tail lengths distributed these disordered methyl groups throughout the middle third of the bilayer. Distributions in mobility and ordering reveal diverse properties that cannot be obtained with monodisperse lipids.
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Affiliation(s)
- Faramarz Joodaki
- Department of Chemical Engineering, University of Rhode Island, 360 Fascitelli Center for Advanced Engineering, Kingston, Rhode Island 02881, United States
| | - Lenore M Martin
- Department of Cell and Molecular Biology, University of Rhode Island, 120 Flagg Road, Kingston, Rhode Island 02881, United States
| | - Michael L Greenfield
- Department of Chemical Engineering, University of Rhode Island, 360 Fascitelli Center for Advanced Engineering, Kingston, Rhode Island 02881, United States
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Le MNT, Kawada-Matsuo M, Komatsuzawa H. Efficiency of Antimicrobial Peptides Against Multidrug-Resistant Staphylococcal Pathogens. Front Microbiol 2022; 13:930629. [PMID: 35756032 PMCID: PMC9218695 DOI: 10.3389/fmicb.2022.930629] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 05/18/2022] [Indexed: 11/13/2022] Open
Abstract
Antibiotics play a vital role in saving millions of lives from fatal infections; however, the inappropriate use of antibiotics has led to the emergence and propagation of drug resistance worldwide. Multidrug-resistant bacteria represent a significant challenge to treating infections due to the limitation of available antibiotics, necessitating the investigation of alternative treatments for combating these superbugs. Under such circumstances, antimicrobial peptides (AMPs), including human-derived AMPs and bacteria-derived AMPs (so-called bacteriocins), are considered potential therapeutic drugs owing to their high efficacy against infectious bacteria and the poor ability of these microorganisms to develop resistance to them. Several staphylococcal species including Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus, and Staphylococcus saprophyticus are commensal bacteria and known to cause many opportunistic infectious diseases. Methicillin-resistant Staphylococci, especially methicillin-resistant S. aureus (MRSA), are of particular concern among the critical multidrug-resistant infectious Gram-positive pathogens. Within the past decade, studies have reported promising AMPs that are effective against MRSA and other methicillin-resistant Staphylococci. This review discusses the sources and mechanisms of AMPs against staphylococcal species, as well as their potential to become chemotherapies for clinical infections caused by multidrug-resistant staphylococci.
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Affiliation(s)
- Mi Nguyen-Tra Le
- Department of Bacteriology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Miki Kawada-Matsuo
- Department of Bacteriology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Hitoshi Komatsuzawa
- Department of Bacteriology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
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Demirci M, Yigin A, Demir C. Efficacy of antimicrobial peptide LL-37 against biofilm forming Staphylococcus aureus strains obtained from chronic wound infections. Microb Pathog 2021; 162:105368. [PMID: 34942309 DOI: 10.1016/j.micpath.2021.105368] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 12/15/2021] [Accepted: 12/17/2021] [Indexed: 12/26/2022]
Abstract
The antimicrobial peptide LL-37 showed inhibitory effects against Staphylococcus aureus strains, which often responsible for wound infections. Understanding the molecular mechanisms of biofilm-containing wound infections is important. Thus, this study aimed to investigate both the antimicrobial and biofilm efficacy of LL-37 against biofilm-positive methicillin-susceptible S. aureus (MSSA) strains and biofilm-positive methicillin-resistant S. aureus (MRSA) strains obtained from chronic wound infections and its effect on different quorum sensing and virulence genes at suboptimal concentrations. Fifteen biofilm-forming MRSA and 15 biofilm-forming MSSA strains were included in this study. The minimum inhibitory concentration (MIC) values and biofilm formation were tested by microdilution methods. Real-time PCR was performed to determine gene expression levels. MIC values for LL-37 were 89.6 mg/L and 132.3 mg/L for MSSA and MRSA strains, respectively. No statistically significant difference was found between MRSA and MSSA strains in terms of the effect of LL-37 on biofilm formation. A statistically significant difference was found between MRSA and MSSA strains for atlA, RNAIII, and agrA gene expression levels following exposure to a suboptimal concentration of LL-37. Ultimately, the required LL-37 antimicrobial concentration was quite high; however, LL-37 antibiofilm concentration may be acceptable for use in humans against biofilm-forming MRSA and MSSA strains. This is the first study to investigate to effect of a suboptimal LL-37 concentration on gene expression levels of biofilm-forming MSSA and MRSA strains. LL-37 affected quorum sensing and biofilm producing mechanisms, even at suboptimal MIC concentrations.
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Affiliation(s)
- Mehmet Demirci
- Kirklareli University, Medical Faculty, Department of Medical Microbiology, Kirklareli, Turkey.
| | - Akin Yigin
- Harran University, Faculty of Veterinary, Department of Genetics, Sanlıurfa, Turkey
| | - Cemil Demir
- Mardin Artuklu University, Vocational Higher School of Health Services, Department of Medical Services and Techniques, Mardin, Turkey
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Kawada-Matsuo M, Le MNT, Komatsuzawa H. Antibacterial Peptides Resistance in Staphylococcus aureus: Various Mechanisms and the Association with Pathogenicity. Genes (Basel) 2021; 12:genes12101527. [PMID: 34680923 PMCID: PMC8535901 DOI: 10.3390/genes12101527] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 01/15/2023] Open
Abstract
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.
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Masadeh MM, Alzoubi KH, Masadeh MM, Aburashed ZO. Metformin as a Potential Adjuvant Antimicrobial Agent Against Multidrug Resistant Bacteria. Clin Pharmacol 2021; 13:83-90. [PMID: 34007223 PMCID: PMC8123943 DOI: 10.2147/cpaa.s297903] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 04/13/2021] [Indexed: 12/13/2022] Open
Abstract
Introduction The continuous increase in the incidence of bacterial resistance to existing antibiotics represents a worldwide health burden. A surrogate strategy to combat such crisis is to find compounds that restore the antimicrobial activity of the already existing antibiotics against multidrug resistant bacteria. Metformin is a commonly used antidiabetic medication. It has proven benefits in other diseases including cancer, aging-related and infectious diseases. In this study, the potential effect of metformin as an adjuvant therapy to antibiotics was investigated. Methods Two multidrug resistant bacterial strains were used; methicillin-resistant Staphylococcus aureus (MRSA; ATCC 33,591) and multidrug resistant Pseudomonas aeruginosa (ATCC BAA-2114). To assess its efficacy, metformin was combined with several antibiotics: levofloxacin, chloramphenicol, rifampicin, ampicillin, and doxycycline. The antibacterial effect of metformin was tested using the micro broth dilution method. The minimum inhibitory concentration (MIC) was also measured. Cytotoxicity studies were also performed on mammalian cells to assess its safety. Results Metformin exhibited an antibacterial effect when combined with the antibiotics on the two tested strains. It also showed low toxicity on the mammalian cells. Moreover, synergetic studies showed that metformin enhanced the effect of the combined antibiotics, as these combinations provide either a synergistic or additive effect with significant reduction in the MIC. Conclusion Metformin exerts an adjuvant antibacterial effect; thus, it could be a possible candidate as an adjuvant therapy to reduce antimicrobial resistance.
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Affiliation(s)
- Majed M Masadeh
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Karem H Alzoubi
- Department of Clinical Pharmacy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
| | - Majd M Masadeh
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Zainah O Aburashed
- Department of Clinical Pharmacy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
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Chowdhury T, Mandal SM, Kumari R, Ghosh AK. Purification and characterization of a novel antimicrobial peptide (QAK) from the hemolymph of Antheraea mylitta. Biochem Biophys Res Commun 2020; 527:411-417. [DOI: 10.1016/j.bbrc.2020.04.050] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 04/11/2020] [Indexed: 12/11/2022]
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Lee HH, Lee GY, Eom HS, Yang SJ. Occurrence and Characteristics of Methicillin-Resistant and -Susceptible Staphylococcus aureus Isolated from the Beef Production Chain in Korea. Food Sci Anim Resour 2020; 40:401-414. [PMID: 32426719 PMCID: PMC7207094 DOI: 10.5851/kosfa.2020.e20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 01/29/2020] [Accepted: 03/06/2020] [Indexed: 01/12/2023] Open
Abstract
The emergence and persistence of methicillin-susceptible Staphylococcus
aureus (MSSA) and methicillin-resistant S. aureus
(MRSA) in livestock animals have been reported as a potential risk factor for
transmission to humans. In this study, we investigated the nationwide prevalence
and characteristics of MRSA and MSSA in the Korean beef production system,
including retail markets, slaughterhouses, and cattle farms. From a total of
1,285 samples, only 5 MRSA strains were isolated: from a farmer (1 ST72 MRSA), a
carcass sample from a slaughterhouse (1 ST72 MRSA), and beef cattle (3 ST5
MRSA). In addition, 11 MSSA strains were isolated from beef cattle (n=3),
humans (1 farmer, 1 slaughterhouse worker, and 4 retail market workers), and
carcass samples (n=1) and slaughterhouse environment (n=1).
Although the prevalence of MRSA and MSSA in beef cattle was much lower than that
reported in pigs, 5/5 MRSA and 2/11 MSSA strains displayed multiple drug
resistance (MDR) phenotypes. Unlike the swine-associated MRSA, no correlation
was found between tetracycline/zinc resistance and MDR phenotype. However, MRSA
strains had an identical set of staphylococcal enterotoxins and exhibited
enhanced levels of resistance to antimicrobial peptides (PMAP-36 and LL-37)
compared to the MSSA strains. In conclusion, continued and systemic surveillance
of livestock, meat products, and humans in close contact with livestock/meat
products is necessary to prevent the transmission of MRSA and MSSA to
humans.
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Affiliation(s)
- Haeng Ho Lee
- School of Bioresources and Bioscience, Chung-Ang University, Anseong 17547, Korea
| | - Gi Yong Lee
- School of Bioresources and Bioscience, Chung-Ang University, Anseong 17547, Korea
| | - Hong Sik Eom
- School of Bioresources and Bioscience, Chung-Ang University, Anseong 17547, Korea
| | - Soo-Jin Yang
- School of Bioresources and Bioscience, Chung-Ang University, Anseong 17547, Korea
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9
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Human Defensins: A Novel Approach in the Fight against Skin Colonizing Staphylococcus a ureus. Antibiotics (Basel) 2020; 9:antibiotics9040198. [PMID: 32326312 PMCID: PMC7235756 DOI: 10.3390/antibiotics9040198] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/15/2020] [Accepted: 04/20/2020] [Indexed: 12/13/2022] Open
Abstract
Staphylococcus aureus is a microorganism capable of causing numerous diseases of the human skin. The incidence of S. aureus skin infections reflects the conflict between the host skin′s immune defenses and the S. aureus’ virulence elements. Antimicrobial peptides (AMPs) are small protein molecules involved in numerous biological activities, playing a very important role in the innate immunity. They constitute the defense of the host′s skin, which prevents harmful microorganisms from entering the epithelial barrier, including S. aureus. However, S. aureus uses ambiguous mechanisms against host defenses by promoting colonization and skin infections. Our review aims to provide a reference collection on host-pathogen interactions in skin disorders, including S. aureus infections and its resistance to methicillin (MRSA). In addition to these, we discuss the involvement of defensins and other innate immunity mediators (i.e., toll receptors, interleukin-1, and interleukin-17), involved in the defense of the host against the skin disorders caused by S. aureus, and then focus on the evasion mechanisms developed by the pathogenic microorganism under analysis. This review provides the “state of the art” on molecular mechanisms underlying S. aureus skin infection and the pharmacological potential of AMPs as a new therapeutic strategy, in order to define alternative directions in the fight against cutaneous disease.
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El-Kazzaz SS, Abou El-Khier NT. Effect of the lantibiotic nisin on inhibitory and bactericidal activities of antibiotics used against vancomycin-resistant enterococci. J Glob Antimicrob Resist 2020; 22:263-269. [PMID: 32169681 DOI: 10.1016/j.jgar.2020.02.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 02/19/2020] [Accepted: 02/23/2020] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES Antibiotic resistance is a serious issue facing clinicians all over the world. Vancomycin-resistant enterococci (VRE) are amongst the most common resistant pathogens that are isolated from patients suffering from infections in our locality. New antimicrobial agents such as the lantibiotic nisin have been previously examined against resistant bacteria as it has strong antibacterial action with no chance of resistance development. This study aimed to explore the effect of nisin in combination with the conventional antibiotics against VRE, with a view to using it as an auxiliary therapy with such antibiotics for combating resistant isolates. METHODS Twenty-three VRE had been examined for the combined effect of nisin with the routine sets of antibiotics using the microplate dilution technique for minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) testing. Checkerboard microbroth assay was conducted for inspection of synergism between nisin and either ampicillin or chloramphenicol. RESULTS An obvious improvement of inhibitory and bactericidal activities of the tested antibiotics after addition of lantibiotic nisin was observed, with a remarkable reduction in the MIC values of vancomycin against all of the isolates. Nisin recorded a synergistic outcome when combined with either ampicillin or chloramphenicol using the checkerboard assay. CONCLUSION Nisin could be effectively considered as a supplementary agent to traditional antibiotics in the management of VRE-associated infections, as it had a synergistic outcome with commonly prescribed antibiotics such as ampicillin and chloramphenicol.
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Affiliation(s)
- Samah Sabry El-Kazzaz
- Medical Microbiology and Immunology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Noha Tharwat Abou El-Khier
- Medical Microbiology and Immunology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt.
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Kenawy ER, Berber MR, Saad-Allah K, Azaam M. Synthesis of montmorillonite-based tris(2-ethylamine)-Schiff-base composites with remarkable antibacterial activity. JOURNAL OF SAUDI CHEMICAL SOCIETY 2020. [DOI: 10.1016/j.jscs.2019.09.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Xu X, Zhang L, Cai Y, Liu D, Shang Z, Ren Q, Li Q, Zhao W, Chen Y. Inhibitor discovery for the E. coli meningitis virulence factor IbeA from homology modeling and virtual screening. J Comput Aided Mol Des 2019; 34:11-25. [PMID: 31792885 DOI: 10.1007/s10822-019-00250-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Accepted: 11/08/2019] [Indexed: 11/28/2022]
Abstract
Escherichia coli (E. coli) K1 is the most common Gram-negative bacteria cause of neonatal meningitis. The penetration of E. coli through the blood-brain barrier is a key step of the meningitis pathogenesis. A host receptor protein, Caspr1, interacts with the E. coli virulence factor IbeA and thus facilitates bacterial penetration through the blood-brain barrier. Based on this result, we have now predicted the binding pattern between Caspr1 and IbeA by an integrated computational protocol. Based on the predicted model, we have identified a putative molecular binding pocket in IbeA, that directly bind with Caspr1. This evidence indicates that the IbeA (229-343aa) region might play a key role in mediating the bacteria invasion. Virtual screening with the molecular model was conducted to search for potential inhibitors from 213,279 commercially available chemical compounds. From the top 50 identified compounds, 9 demonstrated a direct binding ability to the residues within the Caspr1 binding site on IbeA. By using human brain microvascular endothelial cells (hBMEC) with E. coli strain RS218, four molecules were characterized that significantly attenuated the bacteria invasions at concentrations devoid of cell toxicity. Our study provides useful structural information for understanding the pathogenesis of neonatal meningitis, and have identified drug-like compounds that could be used to develop effective anti-meningitis agents.
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Affiliation(s)
- Xiaoqian Xu
- Department of Developmental Biology, Key Laboratory of Cell Biology, Ministry of Public Health and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, China.
| | - Li Zhang
- Department of Life Science, Liaoning University, Shenyang, China
| | - Ying Cai
- Department of Developmental Biology, Key Laboratory of Cell Biology, Ministry of Public Health and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, China
| | - Dongxin Liu
- Department of Developmental Biology, Key Laboratory of Cell Biology, Ministry of Public Health and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, China
| | - Zhengwen Shang
- Department of Developmental Biology, Key Laboratory of Cell Biology, Ministry of Public Health and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, China
| | - Qiuhong Ren
- Department of Developmental Biology, Key Laboratory of Cell Biology, Ministry of Public Health and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, China
| | - Qiong Li
- Department of Life Science, University of Science and Technology of China, Hefei, China
| | - Weidong Zhao
- Department of Developmental Biology, Key Laboratory of Cell Biology, Ministry of Public Health and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, China
| | - Yuhua Chen
- Department of Developmental Biology, Key Laboratory of Cell Biology, Ministry of Public Health and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, China.
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Almaaytah A, Abualhaijaa A, Alqudah O. The evaluation of the synergistic antimicrobial and antibiofilm activity of AamAP1-Lysine with conventional antibiotics against representative resistant strains of both Gram-positive and Gram-negative bacteria. Infect Drug Resist 2019; 12:1371-1380. [PMID: 31213855 PMCID: PMC6537036 DOI: 10.2147/idr.s204626] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 04/10/2019] [Indexed: 12/19/2022] Open
Abstract
Background and purpose: Antimicrobial resistance toward antibiotics is reaching historical unprecedented levels. There is an urgent and imminent need to develop novel antimicrobial alternatives. Antimicrobial peptides could prove to be a successful group of antimicrobials for drug development. Recently, we have designed a novel synthetic peptide named AamAP1-Lysine. The peptide displayed potent wide-spectrum antimicrobial activities against Gram-positive and Gram-negative bacteria. The purpose of this study is to evaluate the antimicrobial effect of combining AamAP1-Lysine with five different conventional antibiotics each representing a distinct mechanism of action in order to explore the possibility of producing a synergistic mode of action against a resistant strain of Gram-positive and a resistant strain of Gram-negative bacteria. Methodology: The antimicrobial activity of AamAP1-Lysine in combination with five different antibiotics were evaluated for their antimicrobial activity employing standard antimicrobial assays, the synergistic activity of the peptide-antibiotic combinations were evaluated using checkerboard technique in addition to real-time time-kill assays. For the antibiofilm studies, the MBEC values were determined by employing the Calgary device. Results: The combination strategy displayed potent synergistic activities against planktonic bacteria in a significant number of peptide-antibiotic combinations. The synergistic activity managed to reduce the effective minimum inhibitory concentration (MIC) concentrations dramatically with some combinations exhibiting a 64-fold decrease in the effective MIC of AamAP1-Lysine individually. Additionally, the combined synergistic activities of the peptide antibiotics were evaluated, and our results have identified two peptide antibiotic combinations with potent synergistic activities against biofilm growing strains of resistant bacteria. Conclusion: Our results clearly indicate that peptide-antibiotic combinations could prove to be a very effective strategy in combatting multidrug-resistant bacteria and biofilm caused infections.
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Affiliation(s)
- Ammar Almaaytah
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
| | - Ahmad Abualhaijaa
- Department of Applied Biological Sciences, Faculty of Science and Arts, Jordan University of Science and Technology, Irbid, Jordan
| | - Obadah Alqudah
- Department of Legal Medicine, Toxicology and Forensic Medicine, Faculty of Medicine, Jordan University of Science and Technology, Irbid, Jordan
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14
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Al Tall Y, Abualhaijaa A, Alsaggar M, Almaaytah A, Masadeh M, Alzoubi KH. Design and characterization of a new hybrid peptide from LL-37 and BMAP-27. Infect Drug Resist 2019; 12:1035-1045. [PMID: 31118709 PMCID: PMC6503343 DOI: 10.2147/idr.s199473] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Accepted: 03/13/2019] [Indexed: 01/11/2023] Open
Abstract
Background and purpose: The world is heading to a post-antibiotic era where the treatment of bacterial infections will not be possible even with well-known last-line antibiotics. Unfortunately, the emergence of multidrug resistant bacterial strains is uncontrollable, and the humanity will face a life-threatening fate unless new antimicrobial agents with new bacterial target sites are promptly developed. Herein, we design a hybrid antimicrobial peptide (B1) from helical parts taken from the parent peptides: LL-37 and BMAP-27. The purpose of this design is to improve the potency and enhance the toxicity profile of the parent peptides. Methods: Rational design was used to hybridize two antimicrobial peptides, in which two helical parts from the bovine analog BMAP-27, and the human cathelicidin LL-37 were used to generate a novel peptide (B1). The physicochemical properties were checked using in silico methods. The antimicrobial activities were tested against nine control and resistant strains of Gram-positive and Gram-negative bacteria. On the other hand, the antibiofilm activities were tested against four resistant strains. The cytotoxicity on mammalian cells was tested using HEK293, and the hemolysis activity was also investigated on human blood. Finally, synergistic studies were performed with four conventional antibiotics against four resistant strains of Gram-positive and Gram-negative bacteria. Results: The new peptide B1 exhibited broad-spectrum activities against all tested strains. The concentration against planktonic cells ranged between 10 and 20 µM. However, 40-60 µM were needed to eradicate the biofilms. B1 showed reduced toxicity toward mammalian cells with minimal hemolysis risk. On the other hand, the synergistic studies showed improved activities for the combined conventional antibiotics with a huge reduction in their minimum inhibitory concentration values. The concentrations of B1 peptide combined with the tested antibiotics were also decreased markedly down to 0.5 µM in some cases. Conclusion: B1 is a hybrid peptide from two cathelicidin peptides. It showed an improved activity compared to parent peptides. The hybridization was successful in this study. It generated a new potent broad-spectrum antimicrobial. The toxicity profile was improved, and the synergism with the convention antibiotics showed promising results.
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Affiliation(s)
| | | | | | | | | | - Karem H Alzoubi
- Department of Clinical Pharmacy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
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Lee GY, Lee HH, Hwang SY, Hong J, Lyoo KS, Yang SJ. Carriage of Staphylococcus schleiferi from canine otitis externa: antimicrobial resistance profiles and virulence factors associated with skin infection. J Vet Sci 2019; 20:e6. [PMID: 30944529 PMCID: PMC6441802 DOI: 10.4142/jvs.2019.20.e6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 02/23/2019] [Accepted: 02/25/2019] [Indexed: 11/20/2022] Open
Abstract
The recent emergence of Staphylococcus schleiferi in dogs with otitis externa or skin and soft tissue infections has become a significant zoonotic issues. In the current study, we investigated 1) the carriage rates of S. schleiferi among major staphylococci in healthy dogs and dogs with otitis externa, 2) antibiotic susceptibility profiles of S. schleiferi, particularly methicillin resistance (MR), and 3) virulence factors associated with skin and soft tissue infections such as ability to form biofilm, resistance to cationic antimicrobial peptides (CAMPs), and carriage of staphylococcal enterotoxin genes. Among the 21 S. schleiferi isolates, 5 isolates (24%) were determined to be methicillin-resistant (MRSS). Staphylococcal cassette chromosome mec (SCCmec) typing revealed the presence of SCCmec type V in 4 MRSS isolates and type VII in one MRSS. Higher levels of antibiotic resistance, especially multidrug resistance, were observed in MRSS isolates compared to the methicillin-susceptible S. schleiferi (MSSS) isolates. In addition, MRSS isolates exhibited enhanced ability to form biofilm under static condition and all the 5 MRSS isolates carried three or more enterotoxin genes. However, there were no significant differences in resistance to CAMPs between MRSS and MSSS isolates. These findings suggest that coagulase-negative S. schleiferi is becoming more prevalent in canine otitis externa cases. Our results also highlight the presence of multidrug-resistant MRSS isolates with enhanced biofilm production and carriage of multiple enterotoxins.
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Affiliation(s)
- Gi Yong Lee
- Department of Animal Science and Technology, School of Bioresources and Bioscience, Chung-Ang University, Anseong 17546, Korea
| | - Hang-Ho Lee
- Department of Animal Science and Technology, School of Bioresources and Bioscience, Chung-Ang University, Anseong 17546, Korea
| | | | - Joonbae Hong
- Korea Consumer Agency, Test & Research Department, Food & Microbiology Team, Eumseong 27738, Korea
| | - Kwang-Soo Lyoo
- Korea Zoonosis Research Institute, Chonbuk National University, Iksan 54896, Korea
| | - Soo-Jin Yang
- Department of Animal Science and Technology, School of Bioresources and Bioscience, Chung-Ang University, Anseong 17546, Korea
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Rozenbaum RT, Su L, Umerska A, Eveillard M, Håkansson J, Mahlapuu M, Huang F, Liu J, Zhang Z, Shi L, van der Mei HC, Busscher HJ, Sharma PK. Antimicrobial synergy of monolaurin lipid nanocapsules with adsorbed antimicrobial peptides against Staphylococcus aureus biofilms in vitro is absent in vivo. J Control Release 2018; 293:73-83. [PMID: 30465823 DOI: 10.1016/j.jconrel.2018.11.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 11/16/2018] [Indexed: 12/22/2022]
Abstract
Bacterial infections are mostly due to bacteria in their biofilm-mode of growth, while penetrability of antimicrobials into infectious biofilms and increasing antibiotic resistance hamper infection treatment. In-vitro, monolaurin lipid nanocapsules (ML-LNCs) carrying adsorbed antimicrobial peptides (AMPs) displayed synergistic efficacy against planktonic Staphylococcus aureus, but it has not been demonstrated, neither in-vitro nor in-vivo, that such ML-LNCs penetrate into infectious S. aureus biofilms and maintain synergy with AMPs. This study investigates the release mechanism of AMPs from ML-LNCs and possible antimicrobial synergy of ML-LNCs with the AMPs DPK-060 and LL-37 against S. aureus biofilms in-vitro and in a therapeutic, murine, infected wound-healing model. Zeta potentials demonstrated that AMP release from ML-LNCs was controlled by the AMP concentration in suspension. Both AMPs demonstrated no antimicrobial efficacy against four staphylococcal strains in a planktonic mode, while a checkerboard assay showed synergistic antimicrobial efficacy when ML-LNCs and DPK-060 were combined, but not for combinations of ML-LNCs and LL-37. Similar effects were seen for growth reduction of staphylococcal biofilms, with antimicrobial synergy persisting only for ML-LNCs at the highest level of DPK-060 or LL-37 adsorption. Healing of wounds infected with bioluminescent S. aureus Xen36, treated with ML-LNCs alone, was faster when treated with PBS, while AMPs alone did not yield faster wound-healing than PBS. Faster, synergistic wound-healing due to ML-LNCs with adsorbed DPK-060, was absent in-vivo. Summarizing, antimicrobial synergy of ML-LNCs with adsorbed antimicrobial peptides as seen in-vitro, is absent in in-vivo healing of infected wounds, likely because host AMPs adapted the synergistic role of the AMPs added. Thus, conclusions regarding synergistic antimicrobial efficacy, should not be drawn from planktonic data, while even in-vitro biofilm data bear little relevance for the in-vivo situation.
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Affiliation(s)
- René T Rozenbaum
- University of Groningen, University Medical Center Groningen, Department of Biomedical Engineering, P.O Box 196, 9700 AD Groningen, the Netherlands
| | - Linzhu Su
- University of Groningen, University Medical Center Groningen, Department of Biomedical Engineering, P.O Box 196, 9700 AD Groningen, the Netherlands; State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials, Ministry of Education, Institute of Polymer Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071, PR China
| | - Anita Umerska
- MINT, UNIV Angers, INSERM U1066, CNRS 6021, Université Bretagne Loire, Angers, Cedex, France
| | - Matthieu Eveillard
- Equipe ATIP AVENIR, CRCINA, Inserm, Université de Nantes, Université d'Angers, Angers, France
| | - Joakim Håkansson
- Research Institutes of Sweden, Division Biosciences and Materials, Section for Medical Technology, Box 857, 50115 Borås, Sweden
| | - Margit Mahlapuu
- Promore Pharma, Karolinska Institutet Science Park, Fogdevreten 2, SE-171 65, Solna, Sweden
| | - Fan Huang
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science, Peking Union Medical College, Tianjin 300192, PR China
| | - Jianfeng Liu
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science, Peking Union Medical College, Tianjin 300192, PR China.
| | - Zhenkun Zhang
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials, Ministry of Education, Institute of Polymer Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071, PR China
| | - Linqi Shi
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials, Ministry of Education, Institute of Polymer Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071, PR China
| | - Henny C van der Mei
- University of Groningen, University Medical Center Groningen, Department of Biomedical Engineering, P.O Box 196, 9700 AD Groningen, the Netherlands
| | - Henk J Busscher
- University of Groningen, University Medical Center Groningen, Department of Biomedical Engineering, P.O Box 196, 9700 AD Groningen, the Netherlands
| | - Prashant K Sharma
- University of Groningen, University Medical Center Groningen, Department of Biomedical Engineering, P.O Box 196, 9700 AD Groningen, the Netherlands.
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Wang S, Yan C, Zhang X, Shi D, Chi L, Luo G, Deng J. Antimicrobial peptide modification enhances the gene delivery and bactericidal efficiency of gold nanoparticles for accelerating diabetic wound healing. Biomater Sci 2018; 6:2757-2772. [PMID: 30187036 DOI: 10.1039/c8bm00807h] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Impaired angiogenesis and bacterial infection have increasingly been implicated as the major causes of delayed diabetic wound healing. However, there is currently no effective therapy. Here, we optimized a novel gene delivery system based on antimicrobial peptide (LL37) grafted ultra-small gold nanoparticles (AuNPs@LL37, ∼7 nm) for the topical treatment of diabetic wounds with or without bacterial infection. AuNPs@LL37 combines the advantages of cationic AuNPs that condense DNA with those of antibacterial peptides, which are both highly antibacterial and essential for enhancing cellular and nucleus entry to achieve high gene delivery efficiency. AuNPs@LL37 combined with pro-angiogenic (VEGF) plasmids (AuNPs@LL37/pDNAs) significantly improved the gene transfection efficiency in keratinocytes compared with pristine AuNPs/pDNAs, and showed similar expression to Lipo2000/pDNAs (a well-known highly efficient gene transfection agent). Moreover, our therapeutic depot showed higher antibacterial ability than the free antimicrobial peptides and the cationic AuNPs alone in vitro and in vivo due to synergistic effects. Furthermore, the combined system promoted angiogenesis and inhibited bacterial infection in diabetic wounds, resulting in accelerated wound closure rates, faster re-epithelization, improved granulation tissue formation and high VEGF expression. Finally, our therapeutic depot was highly biocompatible in vitro and in vivo, suggesting its potential as a feasible way to treat chronic diabetic wounds.
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Affiliation(s)
- Song Wang
- Institute of Burn Research, Southwest Hospital, State Key Lab of Trauma, Burn and Combined Injury, Third Military Medical University (Army Medical University), Chongqing 400038, China.
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Almaaytah A, Qaoud MT, Abualhaijaa A, Al-Balas Q, Alzoubi KH. Hybridization and antibiotic synergism as a tool for reducing the cytotoxicity of antimicrobial peptides. Infect Drug Resist 2018; 11:835-847. [PMID: 29910626 PMCID: PMC5987794 DOI: 10.2147/idr.s166236] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Introduction As the development of new antimicrobial agents faces a historical decline, the issue of bacterial drug resistance has become a serious dilemma that threatens the human population worldwide. Antimicrobial peptides (AMPs) represent an attractive and a promising class of antimicrobial agents. Aim The hybridization of AMPs aimed at merging two individual active fragments of native peptides to generate a new AMP with altered physicochemical properties that translate into an enhanced safety profile. Materials and methods In this study, we have rationally designed a new hybrid peptide via combining two individual α-helical fragments of both BMAP-27 and OP-145. The resultant peptide, was evaluated for its antimicrobial and antibiofilm activity against a range of microbial strains. The resultant peptide was also evaluated for its toxicity against mammalian cells using hemolytic and anti proliferative assays. Results The antimicrobial activity of H4 revealed that the peptide is displaying a broad spectrum of activity against both Gram-positive and Gram-negative bacteria including standard and multidrug-resistant bacterial strains in the range of 2.5-25 μM. The new hybrid peptide displayed potent activity in eradicating biofilm-forming cells, and the reported minimum biofilm eradication concentrations were equal to the minimum inhibitory concentration values reported for planktonic cells. Additionally, H4 exhibited reduced toxicity profiles against eukaryotic cells. Combining H4 peptide with conventional antibiotics has led to a dramatic enhancement of the antimicrobial activity of both agents with synergistic or additive outcomes. Conclusion Overall, this study indicates the success of both the hybridization and synergism strategy in developing AMPs as potential antimicrobial therapeutics with reduced toxicity profiles that could be efficiently employed to eradicate resistant bacterial strains and enhance the selectivity and toxicity profiles of native AMPs.
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Affiliation(s)
- Ammar Almaaytah
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
| | - Mohammed T Qaoud
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
| | - Ahmad Abualhaijaa
- Department of Applied Biological Sciences, Faculty of Science and Arts, Jordan University of Science and Technology, Irbid, Jordan
| | - Qosay Al-Balas
- Department of Medicinal Chemistry, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
| | - Karem H Alzoubi
- Department Clinical Pharmacy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
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Pfalzgraff A, Brandenburg K, Weindl G. Antimicrobial Peptides and Their Therapeutic Potential for Bacterial Skin Infections and Wounds. Front Pharmacol 2018; 9:281. [PMID: 29643807 PMCID: PMC5882822 DOI: 10.3389/fphar.2018.00281] [Citation(s) in RCA: 248] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 03/13/2018] [Indexed: 01/10/2023] Open
Abstract
Alarming data about increasing resistance to conventional antibiotics are reported, while at the same time the development of new antibiotics is stagnating. Skin and soft tissue infections (SSTIs) are mainly caused by the so called ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) which belong to the most recalcitrant bacteria and are resistant to almost all common antibiotics. S. aureus and P. aeruginosa are the most frequent pathogens isolated from chronic wounds and increasing resistance to topical antibiotics has become a major issue. Therefore, new treatment options are urgently needed. In recent years, research focused on the development of synthetic antimicrobial peptides (AMPs) with lower toxicity and improved activity compared to their endogenous counterparts. AMPs appear to be promising therapeutic options for the treatment of SSTIs and wounds as they show a broad spectrum of antimicrobial activity, low resistance rates and display pivotal immunomodulatory as well as wound healing promoting activities such as induction of cell migration and proliferation and angiogenesis. In this review, we evaluate the potential of AMPs for the treatment of bacterial SSTIs and wounds and provide an overview of the mechanisms of actions of AMPs that contribute to combat skin infections and to improve wound healing. Bacteria growing in biofilms are more resistant to conventional antibiotics than their planktonic counterparts due to limited biofilm penetration and distinct metabolic and physiological functions, and often result in chronification of infections and wounds. Thus, we further discuss the feasibility of AMPs as anti-biofilm agents. Finally, we highlight perspectives for future therapies and which issues remain to bring AMPs successfully to the market.
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Affiliation(s)
- Anja Pfalzgraff
- Pharmacology and Toxicology, Department of Biology, Chemistry, Pharmacy, Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
| | | | - Günther Weindl
- Pharmacology and Toxicology, Department of Biology, Chemistry, Pharmacy, Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
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Inhibition of the ATP Synthase Eliminates the Intrinsic Resistance of Staphylococcus aureus towards Polymyxins. mBio 2017; 8:mBio.01114-17. [PMID: 28874470 PMCID: PMC5587909 DOI: 10.1128/mbio.01114-17] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Staphylococcus aureus is intrinsically resistant to polymyxins (polymyxin B and colistin), an important class of cationic antimicrobial peptides used in treatment of Gram-negative bacterial infections. To understand the mechanisms underlying intrinsic polymyxin resistance in S. aureus, we screened the Nebraska Transposon Mutant Library established in S. aureus strain JE2 for increased susceptibility to polymyxin B. Nineteen mutants displayed at least 2-fold reductions in MIC, while the greatest reductions (8-fold) were observed for mutants with inactivation of either graS, graR, vraF, or vraG or the subunits of the ATP synthase (atpA, atpB, atpG, or atpH), which during respiration is the main source of energy. Inactivation of atpA also conferred hypersusceptibility to colistin and the aminoglycoside gentamicin, whereas susceptibilities to nisin, gallidermin, bacitracin, vancomycin, ciprofloxacin, linezolid, daptomycin, and oxacillin were unchanged. ATP synthase activity is known to be inhibited by oligomycin A, and the presence of this compound increased polymyxin B-mediated killing of S. aureus Our results demonstrate that the ATP synthase contributes to intrinsic resistance of S. aureus towards polymyxins and that inhibition of the ATP synthase sensitizes S. aureus to this group of compounds. These findings show that by modulation of bacterial metabolism, new classes of antibiotics may show efficacy against pathogens towards which they were previously considered inapplicable. In light of the need for new treatment options for infections with serious pathogens like S. aureus, this approach may pave the way for novel applications of existing antibiotics.IMPORTANCE Bacterial pathogens that cause disease in humans remain a serious threat to public health, and antibiotics are still our primary weapon in treating bacterial diseases. The ability to eradicate bacterial infections is critically challenged by development of resistance to all clinically available antibiotics. Polymyxins constitute an important class of antibiotics for treatment of infections caused by Gram-negative pathogens, whereas Gram-positive bacteria remain largely insusceptible towards class of antibiotics. Here we performed a whole-genome screen among nonessential genes for polymyxin intrinsic resistance determinants in Staphylococcus aureus We found that the ATP synthase is important for polymyxin susceptibility and that inhibition of the ATP synthase sensitizes S. aureus towards polymyxins. Our study provides novel insights into the mechanisms that limit polymyxin activity against S. aureus and provides valuable targets for inhibitors to potentially enable the use of polymyxins against S. aureus and other Gram-positive pathogens.
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Akbar W, Noor MR, Kowal K, Syed T, Soulimane T, Basim GB. Characterization and antibacterial properties of nanoboron powders and nanoboron powder coated textiles. ADV POWDER TECHNOL 2017. [DOI: 10.1016/j.apt.2016.11.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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22
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Antimicrobial and Antibiofilm Activity of Human Cationic Antibacterial Peptide (LL-37) and Its Analogs Against Pan-Drug-Resistant Acinetobacter baumannii. Jundishapur J Microbiol 2017. [DOI: 10.5812/jjm.35857] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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23
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Ravensdale J, Wong Z, O'Brien F, Gregg K. Efficacy of Antibacterial Peptides Against Peptide-Resistant MRSA Is Restored by Permeabilization of Bacteria Membranes. Front Microbiol 2016; 7:1745. [PMID: 27877159 PMCID: PMC5099250 DOI: 10.3389/fmicb.2016.01745] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 10/19/2016] [Indexed: 11/13/2022] Open
Abstract
Clinical application of antimicrobial peptides (AMPs), as with conventional antibiotics, may be compromised by the development of bacterial resistance. This study investigated AMP resistance in methicillin resistant Staphylococcus aureus, including aspects related to the resilience of the resistant bacteria toward the peptides, the stability of resistance when selection pressures are removed, and whether resistance can be overcome by using the peptides with other membrane-permeabilising agents. Genotypically variant strains of S. aureus became equally resistant to the antibacterial peptides melittin and bac8c when grown in sub-lethal concentrations. Subculture of a melittin-resistant strain without melittin for 8 days lowered the minimal lethal concentration of the peptide from 170 μg ml-1 to 30 μg ml-1. Growth for 24 h in 12 μg ml-1 melittin restored the MLC to 100 μg ml-1. Flow cytometry analysis of cationic fluorophore binding to melittin-naïve and melittin-resistant bacteria revealed that resistance coincided with decreased binding of cationic molecules, suggesting a reduction in nett negative charge on the membrane. Melittin was haemolytic at low concentrations but the truncated analog of melittin, mel12-26, was confirmed to lack haemolytic activity. Although a previous report found that mel12-26 retained full bactericidal activity, we found it to lack significant activity when added to culture medium. However, electroporation in the presence of 50 μg ml-1 of mel12-26, killed 99.3% of the bacteria. Similarly, using a low concentration of the non-ionic detergent Triton X-100 to permeabilize bacteria to mel12-26 markedly increased its bactericidal activity. The observation that bactericidal activity of the non-membranolytic peptide mel12-26 was enhanced when the bacterial membrane was permeablized by detergents or electroporation, suggests that its principal mechanism in reducing bacterial survival may be through interaction with intracellular organelles or processes. Additionally, our results showed that the haemolytic peptide bac8c, had increased antibacterial activity at non-haemolytic concentrations when used with membrane-permeabilizing surfactants.
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Affiliation(s)
- Joshua Ravensdale
- School of Biomedical Science, Faculty of Health and Curtin Health Innovation Research Institute, Curtin University, Bentley WA, Australia
| | - Zachary Wong
- School of Biomedical Science, Faculty of Health and Curtin Health Innovation Research Institute, Curtin University, Bentley WA, Australia
| | - Frances O'Brien
- School of Biomedical Science, Faculty of Health and Curtin Health Innovation Research Institute, Curtin University, BentleyWA, Australia; Australian Collaborative Centre for Enterococcal and Staphylococcal Species (ACCESS) Typing and Research, Curtin University and PathWest Microbiology, Royal Perth Hospital, PerthWA, Australia
| | - Keith Gregg
- School of Biomedical Science, Faculty of Health and Curtin Health Innovation Research Institute, Curtin University, Bentley WA, Australia
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Mohamed MF, Abdelkhalek A, Seleem MN. Evaluation of short synthetic antimicrobial peptides for treatment of drug-resistant and intracellular Staphylococcus aureus. Sci Rep 2016; 6:29707. [PMID: 27405275 PMCID: PMC4942614 DOI: 10.1038/srep29707] [Citation(s) in RCA: 190] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 06/21/2016] [Indexed: 02/07/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections present a serious challenge because of the emergence of resistance to numerous conventional antibiotics. Due to their unique mode of action, antimicrobial peptides are novel alternatives to traditional antibiotics for tackling the issue of bacterial multidrug resistance. Herein, we investigated the antibacterial activity of two short novel peptides (WR12, a 12 residue peptide composed exclusively of arginine and tryptophan, and D-IK8, an eight residue β-sheet peptide) against multidrug resistant staphylococci. In vitro, both peptides exhibited good antibacterial activity against MRSA, vancomycin-resistant S. aureus, linezolid-resistant S. aureus, and methicillin-resistant S. epidermidis. WR12 and D-IK8 were able to eradicate persisters, MRSA in stationary growth phase, and showed significant clearance of intracellular MRSA in comparison to both vancomycin and linezolid. In vivo, topical WR12 and D-IK8 significantly reduced both the bacterial load and the levels of the pro-inflammatory cytokines including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in MRSA-infected skin lesions. Moreover, both peptides disrupted established in vitro biofilms of S. aureus and S. epidermidis significantly more so than traditional antimicrobials tested. Taken together, these results support the potential of WR12 and D-IK8 to be used as a topical antimicrobial agent for the treatment of staphylococcal skin infections.
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Affiliation(s)
- Mohamed F. Mohamed
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA
| | - Ahmed Abdelkhalek
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA
| | - Mohamed N. Seleem
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA
- Purdue Institute for Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, IN 47907, USA
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Le J, Dam Q, Schweizer M, Thienphrapa W, Nizet V, Sakoulas G. Effects of vancomycin versus nafcillin in enhancing killing of methicillin-susceptible Staphylococcus aureus causing bacteremia by human cathelicidin LL-37. Eur J Clin Microbiol Infect Dis 2016; 35:1441-7. [PMID: 27234592 DOI: 10.1007/s10096-016-2682-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 05/13/2016] [Indexed: 02/06/2023]
Abstract
Recent studies have demonstrated that anti-staphylococcal beta-lactam antibiotics, like nafcillin, render methicillin-resistant Staphylococcus aureus (MRSA) more susceptible to killing by innate host defense peptides (HDPs), such as cathelicidin LL-37. We compared the effects of growth in 1/4 minimum inhibitory concentration (MIC) of nafcillin or vancomycin on the LL-37 killing of 92 methicillin-susceptible S. aureus (MSSA) isolates. For three randomly selected strains among these, we examined the effects of nafcillin, vancomycin, daptomycin, or linezolid on LL-37 killing and autolysis. Growth in the presence of subinhibitory nafcillin significantly enhanced LL-37 killing of MSSA compared to vancomycin and antibiotic-free controls. Nafcillin also reduced MSSA production of the golden staphylococcal pigment staphyloxanthin in 39 % of pigmented strains vs. 14 % for vancomycin. Among the antibiotics tested, only nafcillin resulted in significantly increased MSSA autolysis. These studies point to additional mechanisms of anti-staphylococcal activity of nafcillin beyond direct bactericidal activity, properties that vancomycin and other antibiotic classes do not exhibit. The ability of nafcillin to enhance sensitivity to innate HDPs may contribute to its superior effectiveness against MSSA, as suggested by studies comparing clinical outcomes to vancomycin treatment.
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Affiliation(s)
- J Le
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Drive, MC 0714, La Jolla, CA, 92093-0714, USA.
| | - Q Dam
- University of California San Diego School of Medicine, La Jolla, CA, USA
| | - M Schweizer
- Iowa City VA Health Care System, Iowa City, IA, USA
- University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - W Thienphrapa
- University of California San Diego School of Medicine, La Jolla, CA, USA
| | - V Nizet
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Drive, MC 0714, La Jolla, CA, 92093-0714, USA
- University of California San Diego School of Medicine, La Jolla, CA, USA
| | - G Sakoulas
- University of California San Diego School of Medicine, La Jolla, CA, USA
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Almaaytah A, Alnaamneh A, Abualhaijaa A, Alshari’ N, Al-Balas Q. In Vitro Synergistic Activities of the Hybrid Antimicrobial Peptide MelitAP-27 in Combination with Conventional Antibiotics Against Planktonic and Biofilm Forming Bacteria. Int J Pept Res Ther 2016. [DOI: 10.1007/s10989-016-9530-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Blodkamp S, Kadlec K, Gutsmann T, Naim HY, von Köckritz-Blickwede M, Schwarz S. In vitro activity of human and animal cathelicidins against livestock-associated methicillin-resistant Staphylococcus aureus. Vet Microbiol 2015; 194:107-111. [PMID: 26453316 DOI: 10.1016/j.vetmic.2015.09.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 09/23/2015] [Accepted: 09/25/2015] [Indexed: 12/21/2022]
Abstract
Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) is an important zoonotic pathogen. An emerging problem in treating S. aureus infections is the increasing resistance against antibiotics. A possible way to overcome this issue is to boost the host immune system and one target are antimicrobial peptides (AMPs), especially cathelicidins. The aim of this study was to characterize the antimicrobial activity of cathelicidins from different animal species against LA-MRSA and to reveal whether major antimicrobial resistance mechanisms influence the bactericidal activity of these peptides. The MICs of 153 LA-MRSA field isolates for different cathelicidins (LL-37, mCRAMP, CAP18, BMAP-27 and BMAP-28) were analysed. The cathelicidin MICs of S. aureus RN4220 and isogenic transformants, that carried 14 functionally active antimicrobial resistance genes, were determined. These resistance genes have been identified in LA-MRSA and specify the resistance mechanisms active efflux, enzymatic inactivation and modification/protection/replacement of target sites. The data showed that mode MIC values for the cathelicidins did not differ among the LA-MRSA isolates of different animal origin. However, distinct differences were detected between the MIC values for the different cathelicidins. MIC values were lowest for bovine cathelicidins (BMAP-27 and BMAP-28) and highest for the human and mouse cathelicidins (LL-37 and mCRAMP). None of the tested antimicrobial resistance genes affected the antimicrobial activity of the cathelicidins. The findings obtained in this study support the hypothesis that cathelicidins might be a promising target to support the host defense against LA-MRSA, especially since the antimicrobial activity of these peptides is not affected by common staphylococcal antimicrobial resistance genes.
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Affiliation(s)
- Stefanie Blodkamp
- Department of Physiological Chemistry, University for Veterinary Medicine, Hannover, Germany; Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut, Neustadt-Mariensee, Germany
| | - Kristina Kadlec
- Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut, Neustadt-Mariensee, Germany
| | - Thomas Gutsmann
- Research group Biophysics, Research Centre Borstel, Borstel, Germany
| | - Hassan Y Naim
- Department of Physiological Chemistry, University for Veterinary Medicine, Hannover, Germany
| | - Maren von Köckritz-Blickwede
- Department of Physiological Chemistry, University for Veterinary Medicine, Hannover, Germany; Research Center for Emerging Infections and Zoonoses (RIZ), University for Veterinary Medicine, Hannover, Germany.
| | - Stefan Schwarz
- Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut, Neustadt-Mariensee, Germany.
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Pence MA, Haste NM, Meharena HS, Olson J, Gallo RL, Nizet V, Kristian SA. Beta-Lactamase Repressor BlaI Modulates Staphylococcus aureus Cathelicidin Antimicrobial Peptide Resistance and Virulence. PLoS One 2015; 10:e0136605. [PMID: 26305782 PMCID: PMC4549145 DOI: 10.1371/journal.pone.0136605] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 08/06/2015] [Indexed: 02/07/2023] Open
Abstract
BlaI is a repressor of BlaZ, the beta-lactamase responsible for penicillin resistance in Staphylococcus aureus. Through screening a transposon library in S. aureus Newman for susceptibility to cathelicidin antimicrobial peptide, we discovered BlaI as a novel cathelicidin resistance factor. Additionally, through integrational mutagenesis in S. aureus Newman and MRSA Sanger 252 strains, we confirmed the role of BlaI in resistance to human and murine cathelidicin and showed that it contributes to virulence in human whole blood and murine infection models. We further demonstrated that BlaI could be a target for innate immune-based antimicrobial therapies; by removing BlaI through subinhibitory concentrations of 6-aminopenicillanic acid, we were able to sensitize S. aureus to LL-37 killing.
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Affiliation(s)
- Morgan A. Pence
- Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, CA, United States of America
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA, United States of America
| | - Nina M. Haste
- Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, CA, United States of America
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, United States of America
| | - Hiruy S. Meharena
- Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, CA, United States of America
| | - Joshua Olson
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA, United States of America
| | - Richard L. Gallo
- Department of Dermatology, School of Medicine, University of California San Diego, La Jolla, CA, United States of America
- VA San Diego Healthcare System, San Diego, CA, United States of America
| | - Victor Nizet
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA, United States of America
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, United States of America
- * E-mail: (VN); (SAK)
| | - Sascha A. Kristian
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA, United States of America
- * E-mail: (VN); (SAK)
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Sambanthamoorthy K, Hickman M, Pattabiraman N, Palys T, Wagar EJ. Modulating Acinetobacter baumannii biofilm development with molecules containing 3,4,5-trimethoxy-N,N',N'-trimethylbenzohydrazide moiety. Bioorg Med Chem Lett 2015; 25:2238-42. [PMID: 25881818 DOI: 10.1016/j.bmcl.2015.03.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Revised: 03/01/2015] [Accepted: 03/03/2015] [Indexed: 01/27/2023]
Abstract
In recent years, Acinetobacter baumannii has emerged as a major cause of nosocomial infections, including infections of implanted medical devices. The treatment of infections caused by A. baumannii has been severely hampered due to their frequent resistance to currently available antibiotics, and most importantly the ability of A. baumannii to form biofilms, which plays a significant role in both persistence and antibiotic resistance. The inherent resistance of A. baumannii biofilms to host defenses and antimicrobial agents necessitates the search for novel approaches to deter biofilm formation. Here, we report our findings on nine compounds identified from structure-activity relationship (SAR) studies on an antibiofilm compound LP3134 that was reported earlier by Biofouling2014, 30, 17. Compounds were evaluated for antibiofilm and anti-adherence activities against A. baumannii. The ability of the compounds to prevent biofilm development on urinary catheters was studied. Growth curve experiments indicated that compounds did not affect the planktonic growth of A. baumannii. All compounds inhibited A. baumannii biofilm development as well as impacting early adhesion on abiotic surfaces. Seven compounds were able to deter biofilm development on silicone catheters. Due to the continued rise of emerging multidrug-resistant A. baumannii, results from this study provide foundation for further development of these molecules to treat A. baumannii infections in wounds and medical devices.
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Affiliation(s)
- Karthik Sambanthamoorthy
- Wound Infections, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA.
| | - Mark Hickman
- Division of Experimental Therapeutics, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | | | - Thomas Palys
- Wound Infections, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Eric J Wagar
- Wound Infections, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
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The Design and Functional Characterization of the Antimicrobial and Antibiofilm Activities of BMAP27-Melittin, a Rationally Designed Hybrid Peptide. Int J Pept Res Ther 2014. [DOI: 10.1007/s10989-014-9444-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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31
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Heimlich DR, Harrison A, Mason KM. Host Antimicrobial Peptides in Bacterial Homeostasis and Pathogenesis of Disease. Antibiotics (Basel) 2014; 3:645-76. [PMID: 26029470 PMCID: PMC4448142 DOI: 10.3390/antibiotics3040645] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 11/05/2014] [Accepted: 11/05/2014] [Indexed: 01/10/2023] Open
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. 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.
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Affiliation(s)
- Derek R. Heimlich
- The Research Institute at Nationwide Children’s Center for Microbial Pathogenesis, Columbus, OH 43205, USA; E-Mails: (D.R.H.); (A.H.)
| | - Alistair Harrison
- The Research Institute at Nationwide Children’s Center for Microbial Pathogenesis, Columbus, OH 43205, USA; E-Mails: (D.R.H.); (A.H.)
| | - Kevin M. Mason
- The Research Institute at Nationwide Children’s Center for Microbial Pathogenesis, Columbus, OH 43205, USA; E-Mails: (D.R.H.); (A.H.)
- The Ohio State University College of Medicine, Department of Pediatrics, Columbus, OH 43205, USA
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Colonization and infection of the skin by S. aureus: immune system evasion and the response to cationic antimicrobial peptides. Int J Mol Sci 2014; 15:8753-72. [PMID: 24840573 PMCID: PMC4057757 DOI: 10.3390/ijms15058753] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 05/02/2014] [Accepted: 05/07/2014] [Indexed: 02/08/2023] Open
Abstract
Staphylococcus aureus (S. aureus) is a widespread cutaneous pathogen responsible for the great majority of bacterial skin infections in humans. The incidence of skin infections by S. aureus reflects in part the competition between host cutaneous immune defenses and S. aureus virulence factors. As part of the innate immune system in the skin, cationic antimicrobial peptides (CAMPs) such as the β-defensins and cathelicidin contribute to host cutaneous defense, which prevents harmful microorganisms, like S. aureus, from crossing epithelial barriers. Conversely, S. aureus utilizes evasive mechanisms against host defenses to promote its colonization and infection of the skin. In this review, we focus on host-pathogen interactions during colonization and infection of the skin by S. aureus and methicillin-resistant Staphylococcus aureus (MRSA). We will discuss the peptides (defensins, cathelicidins, RNase7, dermcidin) and other mediators (toll-like receptor, IL-1 and IL-17) that comprise the host defense against S. aureus skin infection, as well as the various mechanisms by which S. aureus evades host defenses. It is anticipated that greater understanding of these mechanisms will enable development of more sustainable antimicrobial compounds and new therapeutic approaches to the treatment of S. aureus skin infection and colonization.
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Enhanced Antimicrobial Activity of AamAP1-Lysine, a Novel Synthetic Peptide Analog Derived from the Scorpion Venom Peptide AamAP1. Pharmaceuticals (Basel) 2014; 7:502-16. [PMID: 24776889 PMCID: PMC4035766 DOI: 10.3390/ph7050502] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 04/09/2014] [Accepted: 04/14/2014] [Indexed: 11/17/2022] Open
Abstract
There is great interest in the development of antimicrobial peptides as a potentially novel class of antimicrobial agents. Several structural determinants are responsible for the antimicrobial and cytolytic activity of antimicrobial peptides. In our study, a new synthetic peptide analog, AamAP1-Lysine from the naturally occurring scorpion venom antimicrobial peptide AamAP1, was designed by modifying the parent peptide in order to increase the positive charge and optimize other physico-chemical parameters involved in antimicrobial activity. AamAP1-Lysine displayed potent antibacterial activity against Gram-positive and Gram-negative bacteria. The minimum inhibitory concentration was in the range of 5 to 15 µM with a 10 fold increase in potency over the parent peptide. The hemolytic and antiproliferative activity of AamAP1-Lysine against eukaryotic mammalian cells was minimal at the concentration range needed to inhibit bacterial growth. The antibacterial mechanism analysis indicated that AamAP1-Lysine is probably inducing bacterial cell death through membrane damage and permeabilization determined by the release of β-galactosidase enzyme from peptide treated E. coli cells. DNA binding studies revealed that AamAP1-Lysine caused complete retardation of DNA migration and could display intracellular activities in addition to the membrane permeabilization mode of action reported earlier. In conclusion, AamAP1-Lysine could prove to be a potential candidate for antimicrobial drug development in future studies.
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34
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Suárez DF, Consuegra J, Trajano VC, Gontijo SML, Guimarães PPG, Cortés ME, Denadai ÂL, Sinisterra RD. Structural and thermodynamic characterization of doxycycline/β-cyclodextrin supramolecular complex and its bacterial membrane interactions. Colloids Surf B Biointerfaces 2014; 118:194-201. [PMID: 24816509 DOI: 10.1016/j.colsurfb.2014.01.028] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 12/10/2013] [Accepted: 01/20/2014] [Indexed: 10/25/2022]
Abstract
Doxycycline is a semi-synthetic antibiotic commonly used for the treatment of many aerobic and anaerobic bacteria. It inhibits the activity of matrix metalloproteinases (MMPs) and affects cell proliferation. In this study, the structural and thermodynamic parameters of free DOX and a DOX/βCD complex were investigated, as well as their interactions and effects on Staphylococcus aureus cells and cellular cytotoxicity. Complexation of DOX and βCD was confirmed to be an enthalpy- and entropy-driven process, and a low equilibrium constant was obtained. Treatment of S. aureus with higher concentrations of DOX or DOX/βCD resulted in an exponential decrease in S. aureus cell size, as well as a gradual neutralization of zeta potential. These thermodynamic profiles suggest that ion-pairing and hydrogen bonding interactions occur between DOX and the membrane of S. aureus. In addition, the adhesion of βCD to the cell membrane via hydrogen bonding is hypothesized to mediate a synergistic effect which accounts for the higher activity of DOX/βCD against S. aureus compared to pure DOX. Lower cytotoxicity and induction of osteoblast proliferation was also associated with DOX/βCD compared with free DOX. These promising findings demonstrate the potential for DOX/βCD to mediate antimicrobial activity at lower concentrations, and provides a strategy for the development of other antimicrobial formulations.
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Affiliation(s)
- Diego F Suárez
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Av. Antonio Carlos 6627, Pampulha, 31270-901, Belo Horizonte, MG, Brazil
| | - Jessika Consuegra
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antonio Carlos 6627, Pampulha, 31270-901, Belo Horizonte, MG, Brazil
| | - Vivianne C Trajano
- Departamento de Odontologia Restauradora, Faculdade de Odontologia, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Pampulha, 31270-901, Belo Horizonte, MG, Brazil(1)
| | - Sávio M L Gontijo
- Departamento de Odontologia Restauradora, Faculdade de Odontologia, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Pampulha, 31270-901, Belo Horizonte, MG, Brazil(1)
| | - Pedro P G Guimarães
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Av. Antonio Carlos 6627, Pampulha, 31270-901, Belo Horizonte, MG, Brazil
| | - Maria E Cortés
- Departamento de Odontologia Restauradora, Faculdade de Odontologia, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Pampulha, 31270-901, Belo Horizonte, MG, Brazil(1)
| | - Ângelo L Denadai
- Departamento de Farmácia, Universidade Federal de Juiz de Fora, UFJF, Campus Governador Valadares, MG. Av. Dr. Raimundo Monteiro de Rezende 330, Centro, 35010-177, Governador Valadares, MG, Brazil
| | - Rubén D Sinisterra
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Av. Antonio Carlos 6627, Pampulha, 31270-901, Belo Horizonte, MG, Brazil.
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Almaaytah A, Tarazi S, Alsheyab F, Al-Balas Q, Mukattash T. Antimicrobial and Antibiofilm Activity of Mauriporin, a Multifunctional Scorpion Venom Peptide. Int J Pept Res Ther 2014. [DOI: 10.1007/s10989-014-9405-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Tong Z, Zhang Y, Ling J, Ma J, Huang L, Zhang L. An in vitro study on the effects of nisin on the antibacterial activities of 18 antibiotics against Enterococcus faecalis. PLoS One 2014; 9:e89209. [PMID: 24586598 PMCID: PMC3930635 DOI: 10.1371/journal.pone.0089209] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 01/16/2014] [Indexed: 01/06/2023] Open
Abstract
Enterococcus faecalis rank among the leading causes of nosocomial infections worldwide and possesses both intrinsic and acquired resistance to a variety of antibiotics. Development of new antibiotics is limited, and pathogens continually generate new antibiotic resistance. Many researchers aim to identify strategies to effectively kill this drug-resistant pathogen. Here, we evaluated the effect of the antimicrobial peptide nisin on the antibacterial activities of 18 antibiotics against E. faecalis. The MIC and MBC results showed that the antibacterial activities of 18 antibiotics against E. faecalis OG1RF, ATCC 29212, and strain E were significantly improved in the presence of 200 U/ml nisin. Statistically significant differences were observed between the results with and without 200 U/ml nisin at the same concentrations of penicillin or chloramphenicol (p<0.05). The checkerboard assay showed that the combination of nisin and penicillin or chloramphenicol had a synergetic effect against the three tested E. faecalis strains. The transmission electron microscope images showed that E. faecalis was not obviously destroyed by penicillin or chloramphenicol alone but was severely disrupted by either antibiotic in combination with nisin. Furthermore, assessing biofilms by a confocal laser scanning microscope showed that penicillin, ciprofloxacin, and chloramphenicol all showed stronger antibiofilm actions in combination with nisin than when these antibiotics were administered alone. Therefore, nisin can significantly improve the antibacterial and antibiofilm activities of many antibiotics, and certain antibiotics in combination with nisin have considerable potential for use as inhibitors of this drug-resistant pathogen.
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Affiliation(s)
- Zhongchun Tong
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yuejiao Zhang
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Junqi Ling
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
- * E-mail:
| | - Jinglei Ma
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Lijia Huang
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Luodan Zhang
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China
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Nafcillin enhances innate immune-mediated killing of methicillin-resistant Staphylococcus aureus. J Mol Med (Berl) 2013; 92:139-49. [PMID: 24297496 DOI: 10.1007/s00109-013-1100-7] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 10/15/2013] [Accepted: 10/31/2013] [Indexed: 12/15/2022]
Abstract
UNLABELLED Based on in vitro synergy studies, the addition of nafcillin to daptomycin was used to treat refractory methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. Daptomycin is a de facto cationic antimicrobial peptide in vivo, with antistaphylococcal mechanisms reminiscent of innate host defense peptides (HDPs). In this study, the effects of nafcillin on HDP activity against MRSA were examined in vitro and in vivo. Exposures to β-lactam antimicrobials in general, and nafcillin in particular, significantly increased killing of S. aureus by selected HDPs from keratinocytes, neutrophils, and platelets. This finding correlated with enhanced killing of MRSA by whole blood, neutrophils, and keratinocytes after growth in nafcillin. Finally, nafcillin pretreatment ex vivo reduced MRSA virulence in a murine subcutaneous infection model. Despite the lack of direct activity against MRSA, these studies show potent, consistent, and generalized nafcillin-mediated "sensitization" to increased killing of MRSA by various components of the innate host response. The use of nafcillin as adjunctive therapy in MRSA bacteremia merits further study and should be considered in cases refractory to standard therapy. KEY MESSAGES Nafcillin has been used as adjunctive therapy to clear persistent MRSA bacteremia. Nafcillin enhances killing of MRSA by a cadre of innate host defense peptides. Nafcillin increases binding of human cathelicidin LL-37 to the MRSA membrane. Nafcillin enhances killing of MRSA by neutrophils. Nafcillin reduces virulence of MRSA in a murine subcutaneous infection model.
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Feng X, Sambanthamoorthy K, Palys T, Paranavitana C. The human antimicrobial peptide LL-37 and its fragments possess both antimicrobial and antibiofilm activities against multidrug-resistant Acinetobacter baumannii. Peptides 2013; 49:131-7. [PMID: 24071034 DOI: 10.1016/j.peptides.2013.09.007] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 09/12/2013] [Accepted: 09/12/2013] [Indexed: 02/06/2023]
Abstract
Acinetobacter baumannii infections are difficult to treat due to multidrug resistance. Biofilm formation by A. baumannii is an additional factor in its ability to resist antimicrobial therapy. The antibacterial and antibiofilm activities of the human antimicrobial peptide LL-37 and its fragments KS-30, KR-20 and KR-12 against clinical isolates of multidrug-resistant (MDR) A. baumannii were evaluated. The minimal inhibitory concentration (MIC) of LL-37 against MDR A. baumannii isolates ranged from 16 to 32 μg/mL. The MIC of KS-30 fragment varied from 8.0 to 16 μg/mL and the KR-20 fragment MIC ranged from 16 to 64 μg/mL. LL-37 and KS-30 fragment exhibited 100% bactericidal activity against five A. baumannii strains, including four MDR clinical isolates, within 30 min at concentrations of 0.25-1 μg/mL. By 0.5h, the fragments KR-20 and KR-12 eliminated all tested strains at 8 and 64 μg/mL respectively. LL-37 and its fragments displayed anti-adherence activities between 32-128 μg/mL. A minimum biofilm eradication concentration (MBEC) biofilm assay demonstrated that LL-37 inhibited and dispersed A. baumannii biofilms at 32 μg/mL respectively. Truncated fragments of LL-37 inhibited biofilms at concentrations of 64-128 μg/mL. KS-30, the truncated variant of LL-37, effectively dispersed biofilms at 64 μg/mL. At 24h, no detectable toxicity was observed at the efficacious doses when cytotoxicity assays were performed. Thus, LL-37, KS-30 and KR-20 exhibit significant antimicrobial activity against MDR A. baumannii. The prevention of biofilm formation in vitro by LL-37, KS-30 and KR-20 adds significance to their efficacy. These peptides can be potential therapeutics against MDR A. baumannii infections.
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Affiliation(s)
- Xiaorong Feng
- Department of Wound Infections, Bacterial Diseases Branch, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
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39
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Oral biosciences: The annual review 2012. J Oral Biosci 2013. [DOI: 10.1016/j.job.2013.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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40
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Zecconi A, Scali F. Staphylococcus aureus virulence factors in evasion from innate immune defenses in human and animal diseases. Immunol Lett 2013; 150:12-22. [PMID: 23376548 DOI: 10.1016/j.imlet.2013.01.004] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 12/09/2012] [Accepted: 01/08/2013] [Indexed: 01/04/2023]
Abstract
In the last decades, Staphylococcus aureus acquired a dramatic relevance in human and veterinary medicine for different reasons, one of them represented by the increasing prevalence of antibiotic resistant strains. However, antibiotic resistance is not the only weapon in the arsenal of S. aureus. Indeed, these bacteria have plenty of virulence factors, including a vast ability to evade host immune defenses. The innate immune system represents the first line of defense against invading pathogens. This system consists of three major effector mechanisms: antimicrobial peptides and enzymes, the complement system and phagocytes. In this review, we focused on S. aureus virulence factors involved in the immune evasion in the first phases of infection: TLR recognition avoidance, adhesins affecting immune response and resistance to host defenses peptides and polypeptides. Studies of innate immune defenses and their role against S. aureus are important in human and veterinary medicine given the problems related to S. aureus antimicrobial resistance. Moreover, due to the pathogen ability to manipulate the immune response, these data are needed to develop efficacious vaccines or molecules against S. aureus.
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Affiliation(s)
- Alfonso Zecconi
- Università degli Studi di Milano, Dip. Scienze Veterinarie e Sanità Pubblica, Via Celoria 10, 20133 Milano, Italy.
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41
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van Sorge NM, Beasley FC, Gusarov I, Gonzalez DJ, von Köckritz-Blickwede M, Anik S, Borkowski AW, Dorrestein PC, Nudler E, Nizet V. Methicillin-resistant Staphylococcus aureus bacterial nitric-oxide synthase affects antibiotic sensitivity and skin abscess development. J Biol Chem 2013; 288:6417-26. [PMID: 23322784 DOI: 10.1074/jbc.m112.448738] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Staphylococcus aureus infections present an enormous global health concern complicated by an alarming increase in antibiotic resistance. S. aureus is among the few bacterial species that express nitric-oxide synthase (bNOS) and thus can catalyze NO production from L-arginine. Here we generate an isogenic bNOS-deficient mutant in the epidemic community-acquired methicillin-resistant S. aureus (MRSA) USA300 clone to study its contribution to virulence and antibiotic susceptibility. Loss of bNOS increased MRSA susceptibility to reactive oxygen species and host cathelicidin antimicrobial peptides, which correlated with increased MRSA killing by human neutrophils and within neutrophil extracellular traps. bNOS also promoted resistance to the pharmaceutical antibiotics that act on the cell envelope such as vancomycin and daptomycin. Surprisingly, bNOS-deficient strains gained resistance to aminoglycosides, suggesting that the role of bNOS in antibiotic susceptibility is more complex than previously observed in Bacillus species. Finally, the MRSA bNOS mutant showed reduced virulence with decreased survival and smaller abscess generation in a mouse subcutaneous infection model. Together, these data indicate that bNOS contributes to MRSA innate immune and antibiotic resistance phenotypes. Future development of specific bNOS inhibitors could be an attractive option to simultaneously reduce MRSA pathology and enhance its susceptibility to commonly used antibiotics.
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Affiliation(s)
- Nina M van Sorge
- Departments of Pediatrics, University of California, San Diego, California 92093, USA
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McNicholaswhj S, Humphreys H, Hughes DF. Susceptibility of <i>Staphylococcus aureus</i> Isolates Causing Bloodstream Infection to the Antimicrobial Peptide LL-37. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/ojmm.2013.31012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Leszczynska K, Namiot D, Byfield FJ, Cruz K, Zendzian-Piotrowska M, Fein DE, Savage PB, Diamond S, McCulloch CA, Janmey PA, Bucki R. Antibacterial activity of the human host defence peptide LL-37 and selected synthetic cationic lipids against bacteria associated with oral and upper respiratory tract infections. J Antimicrob Chemother 2012; 68:610-8. [PMID: 23134677 DOI: 10.1093/jac/dks434] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVES We aim to develop antibacterial peptide mimics resistant to protease degradation, with broad-spectrum activity at sites of infection. METHODS The bactericidal activities of LL-37, ceragenins CSA-13, CSA-90 and CSA-92 and the spermine-conjugated dexamethasone derivative D2S were evaluated using MIC and MBC measurements. Gingival fibroblast counting, interleukin-8 (IL-8) and lactate dehydrogenase (LDH) release from keratinocytes (HaCat) were used to determine effects on cell growth, pro-inflammatory response and toxicity. RESULTS All tested cationic lipids showed stronger bactericidal activity than LL-37. Incubation of Staphylococcus aureus with half the MIC of LL-37 led to the appearance of bacteria resistant to its bactericidal effects, but identical incubations with CSA-13 or D2S did not produce resistant bacteria. Cathelicidin LL-37 significantly increased the total number of gingival fibroblasts, but ceragenins and D2S did not alter gingival fibroblast growth. Cationic lipids showed no toxicity to HaCat cells at concentrations resulting in bacterial killing. CONCLUSIONS These data suggest that cationic lipids such as ceragenins warrant further testing as potential novel antibacterial agents.
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Affiliation(s)
- Katarzyna Leszczynska
- Department of Diagnostic Microbiology, Medical University of Białystok, 15-230 Białystok, Poland
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Kawada-Matsuo M, Komatsuzawa H. Factors affecting susceptibility of Staphylococcus aureus to antibacterial agents. J Oral Biosci 2012. [DOI: 10.1016/j.job.2012.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Skariyachan S, Krishnan RS, Siddapa SB, Salian C, Bora P, Sebastian D. Computer aided screening and evaluation of herbal therapeutics against MRSA infections. Bioinformation 2011; 7:222-33. [PMID: 22125390 PMCID: PMC3218416 DOI: 10.6026/97320630007222] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Accepted: 10/11/2011] [Indexed: 01/09/2023] Open
Abstract
Methicillin resistant Staphylococcus aureus (MRSA), a pathogenic bacterium that causes life threatening outbreaks such as community-onset and nosocomial infections has emerged as 'superbug'. The organism developed resistance to all classes of antibiotics including the best known Vancomycin (VRSA). Hence, there is a need to develop new therapeutic agents. This study mainly evaluates the potential use of botanicals against MRSA infections. Computer aided design is an initial platform to screen novel inhibitors and the data finds applications in drug development. The drug-likeness and efficiency of various herbal compounds were screened by ADMET and docking studies. The virulent factor of most of the MRSA associated infections are Penicillin Binding Protein 2A (PBP2A) and Panton-Valentine Leukocidin (PVL). Hence, native structures of these proteins (PDB: 1VQQ and 1T5R) were used as the drug targets. The docking studies revealed that the active component of Aloe vera, β-sitosterol (3S, 8S, 9S, 10R, 13R, 14S, 17R) -17- [(2R, 5R)-5-ethyl-6-methylheptan-2-yl] -10, 13-dimethyl 2, 3, 4, 7, 8, 9, 11, 12, 14, 15, 16, 17- dodecahydro-1H-cyclopenta [a] phenanthren-3-ol) showed best binding energies of -7.40 kcal/mol and -6.34 kcal/mol for PBP2A and PVL toxin, respectively. Similarly, Meliantriol (1S-1-[ (2R, 3R, 5R)-5-hydroxy-3-[(3S, 5R, 9R, 10R, 13S, 14S, 17S)-3-hydroxy 4, 4, 10, 13, 14-pentamethyl-2, 3, 5, 6, 9, 11, 12, 15, 16, 17-decahydro-1H-cyclopenta[a] phenanthren-17-yl] oxolan-2-yl] -2- methylpropane-1, 2 diol), active compound in Azadirachta indica (Neem) showed the binding energies of -6.02 kcal/mol for PBP2A and -8.94 for PVL toxin. Similar studies were conducted with selected herbal compound based on pharmacokinetic properties. All in silico data tested in vitro concluded that herbal extracts of Aloe-vera, Neem, Guava (Psidium guajava), Pomegranate (Punica granatum) and tea (Camellia sinensis) can be used as therapeutics against MRSA infections.
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Affiliation(s)
- Sinosh Skariyachan
- Department of Biotechnology, Dayananda Sagar College of Engineering, Bangalore, India
| | - Rao Shruti Krishnan
- Department of Biotechnology, Dayananda Sagar College of Engineering, Bangalore, India
| | | | - Chithra Salian
- Department of Biotechnology, Dayananda Sagar College of Engineering, Bangalore, India
| | - Prerana Bora
- Department of Biotechnology, Dayananda Sagar College of Engineering, Bangalore, India
| | - Denoj Sebastian
- Department of Microbiology, University of Calicut, Kerala, India
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Lee HS, Eckmann DM, Lee D, Hickok NJ, Composto RJ. Symmetric pH-dependent swelling and antibacterial properties of chitosan brushes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:12458-65. [PMID: 21894981 PMCID: PMC3191253 DOI: 10.1021/la202616u] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Charged polymer brushes grafted to surfaces are of great interest for antibacterial, biosensor, nanofluidic, and drug delivery applications. In this paper, chitosans with quaternary ammonium salts, CH-Q, were immobilized on silicon oxide and characterized by in situ quartz-crystal microbalance with dissipation, QCM-D, and in situ spectroscopic ellipsometry, SE. Both methods showed that the hydrated film exhibited a minimum thickness of ~40 nm near pH 5 that increased strongly (up to ~80 nm) at lower and higher pH. This symmetric swelling is surprising because CH-Q is a cationic polymer. The CH-Q grafted layer was stable for pH values from 3 to 8 and exhibited rapid, reversible swelling and contraction upon varying pH. The CH-Q layer also reduced S. aureus colonization by a factor of ~30× compared to bare silicon oxide and an amine terminated silane grafted to silicon oxide. This antibacterial characteristic of CH-Q is attributed to the quaternary ammonium salts and the flexible polymer brush.
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Affiliation(s)
- Hyun-Su Lee
- Institute of Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA 19104
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104
| | - David M. Eckmann
- Institute of Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA 19104
| | - Daeyeon Lee
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104
| | - Noreen J. Hickok
- Department of Orthopaedic Surgery and Biochemistry & Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107
| | - Russell J. Composto
- Institute of Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104
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Rieg S, Kaasch AJ, Wehrle J, Hofmann SC, Szymaniak-Vits M, Saborowski V, Jonas D, Kalbacher H, Seifert H, Kern WV. Susceptibility of clinical Staphylococcus aureus isolates to innate defense antimicrobial peptides. Microbes Infect 2011; 13:761-5. [DOI: 10.1016/j.micinf.2011.03.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 01/22/2011] [Accepted: 03/25/2011] [Indexed: 10/18/2022]
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Dean SN, Bishop BM, van Hoek ML. Susceptibility of Pseudomonas aeruginosa Biofilm to Alpha-Helical Peptides: D-enantiomer of LL-37. Front Microbiol 2011; 2:128. [PMID: 21772832 PMCID: PMC3131519 DOI: 10.3389/fmicb.2011.00128] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 05/24/2011] [Indexed: 12/19/2022] Open
Abstract
Pseudomonas aeruginosa is a highly versatile opportunistic pathogen and its ability to produce biofilms is a direct impediment to the healing of wounds and recovery from infection. Interest in anti-microbial peptides (AMPs) has grown due to their potential therapeutic applications and their possible use against antibiotic resistant bacteria. LL-37 is the only cathelicidin expressed by humans. In this study, we tested LL-37 and the effect of a protease-resistant LL-37 peptide mimetic, the peptide enantiomer D-LL-37, for anti-microbial and anti-biofilm activity against P. aeruginosa. Both forms of the peptide were equally effective as AMPs with similar killing kinetics. Circular dichroism spectra were obtained to demonstrate the chirality of D- and L-LL-37, and the trypsin resistance of D-LL-37 was confirmed. The helical cathelicidin from the cobra Naja atra (NA-CATH), and synthetic peptide variations (ATRA-1, ATRA-2, NA-CATH:ATRA1-ATRA1) were also tested. Although the cobra cathelicidin and related peptides had strong anti-microbial activity, those tested did not inhibit Pseudomonas biofilm formation, neither did control peptides. Both D- and L-LL-37 inhibited the attachment of Pseudomonas to a 96-well plate and decreased the amount of pre-formed (established) biofilm. D-LL-37 is able to promote Pseudomonas motility and decrease biofilm formation by altering the rate of twitching as well as by downregulating the expression of the biofilm-related genes, rhlA and rhlB, similar to L-LL-37. Both L- and D-LL-37 protected Galleria mellonella in vivo against Pseudomonas infection, while NA-CATH:ATRA1-ATRA1 peptide did not. This study demonstrates the ability and equivalence of D-LL-37 compared to L-LL-37 to promote bacterial twitching motility and inhibit biofilm formation, and protect against in vivo infection, and suggests that this peptide could be a critical advancement in the development of new treatments for P. aeruginosa infection.
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Affiliation(s)
- Scott N Dean
- Department of Biology, George Mason University Manassas, VA, USA
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Dean SN, Bishop BM, van Hoek ML. Natural and synthetic cathelicidin peptides with anti-microbial and anti-biofilm activity against Staphylococcus aureus. BMC Microbiol 2011; 11:114. [PMID: 21605457 PMCID: PMC3397408 DOI: 10.1186/1471-2180-11-114] [Citation(s) in RCA: 159] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Accepted: 05/23/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Chronic, infected wounds typically contain multiple genera of bacteria, including Staphylococcus aureus, many of which are strong biofilm formers. Bacterial biofilms are thought to be a direct impediment to wound healing. New therapies that focus on a biofilm approach may improve the recovery and healing rate for infected wounds. In this study, cathelicidins and related short, synthetic peptides were tested for their anti-microbial effectiveness as well as their ability to inhibit the ability of S. aureus to form biofilms. RESULTS The helical human cathelicidin LL-37 was tested against S. aureus, and was found to exhibit effective anti-microbial, anti-attachment as well as anti-biofilm activity at concentrations in the low μg/ml range. The effect of peptide chirality and associated protease-resistance was explored through the use of an all-D amino acid peptide, D-LL-37, and in turn compared to scrambled LL-37. Helical cathelicidins have been identified in other animals such as the Chinese cobra, Naja atra (NA-CATH). We previously identified an 11-residue imperfectly repeated pattern (ATRA motif) within the sequence of NA-CATH. A series of short peptides (ATRA-1, -2, -1A), as well as a synthetic peptide, NA-CATH:ATRA1-ATRA1, were designed to explore the significance of the conserved residues within the ATRA motif for anti-microbial activity. The CD spectrum of NA-CATH and NA-CATH:ATRA1-ATRA1 revealed the structural properties of these peptides and suggested that helicity may factor into their anti-microbial and anti-biofilm activities. CONCLUSIONS The NA-CATH:ATRA1-ATRA1 peptide inhibits the production of biofilm by S. aureus in the presence of salt, exhibiting anti-biofilm activity at lower peptide concentrations than NA-CATH, LL-37 and D-LL-37; and demonstrates low cytoxicity against host cells but does not affect bacterial attachment. The peptides utilized in this anti-biofilm approach may provide templates for a new group of anti-microbials and potential future topical therapeutics for treating chronic wound infections.
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Affiliation(s)
- Scott N Dean
- Department of Molecular and Microbiology, George Mason University, Manassas, VA 20110, USA
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Matsuo M, Oogai Y, Kato F, Sugai M, Komatsuzawa H. Growth-phase dependence of susceptibility to antimicrobial peptides in Staphylococcus aureus. MICROBIOLOGY-SGM 2011; 157:1786-1797. [PMID: 21393369 DOI: 10.1099/mic.0.044727-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Bacterial cell surface charge is responsible for susceptibility to cationic antimicrobial peptides. Previously, Staphylococcus aureus dlt and mprF were identified as factors conferring a positive charge upon cell surfaces. In this study, we investigated the regulation of cell surface charge during growth. Using a group of S. aureus MW2 mutants, which are gene-inactivated in 15 types of two-component systems (TCSs), we tested dltC and mprF expression and found that two TCSs, aps and agr, were associated with dltC and mprF expression in a growth phase-dependent manner. The first of these, aps, which had already been identified as a sensor of antimicrobial peptides and a positive regulator of dlt and mprF expression, was expressed strongly in the exponential phase, while its expression was significantly suppressed by agr in the stationary phase, resulting in higher expression of dltC and mprF in the exponential phase and lower expression in the stationary phase. Since both types of expression affected the cell surface charge, the susceptibility to antimicrobial peptides and cationic antibiotics was changed during growth. Furthermore, we found that the ability to sense antimicrobial peptides only functioned in the exponential phase. These results suggest that cell surface charge is tightly regulated during growth in S. aureus.
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Affiliation(s)
- Miki Matsuo
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
| | - Yuichi Oogai
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
| | - Fuminori Kato
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima 734-8553, Japan
| | - Motoyuki Sugai
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima 734-8553, Japan
| | - Hitoshi Komatsuzawa
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
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