Abstract
The inappropriate use of antibiotics and an inadequate control of infections have led to the emergence of resistant strains which represent a major threat to public health and the global economy. Therefore, research and development of a new generation of antimicrobials to mitigate the spread of antibiotic resistance has become imperative. Current research and technology developments have promoted the improvement of antimicrobial agents that can selectively interact with a target site (e.g., a gene or a cellular process) or a specific pathogen. Antimicrobial peptides and metal nanoparticles exemplify a novel approach to treat infectious diseases. Nonetheless, combinatorial treatments have been recently considered as an excellent platform to design and develop the next generation of antibacterial agents. The combination of different drugs offers many advantages over their use as individual chemical moieties; these include a reduction in dosage of the individual drugs, fewer side effects compared to the monotherapy, reduced risk for the development of drug resistance, a better combined response compared to the effect of the individual drugs (synergistic effects), wide-spectrum antibacterial action, and the ability to attack simultaneously multiple target sites, in many occasions leading to an increased antibacterial effect. The selection of the appropriate combinatorial treatment is critical for the successful treatment of infections. Therefore, the design of combinatorial treatments provides a pathway to develop antimicrobial therapeutics with broad-spectrum antibacterial action, bactericidal instead of bacteriostatic mechanisms of action, and better efficacy against multidrug-resistant bacteria.
Introduction
Development of antibacterial resistance is considered one of the leading public health problems, since it has a significant impact on the economy worldwide. Since therapeutic options to treat infections are increasingly being limited due to antibacterial resistance, this escalates the morbidity and mortality associated with infectious diseases caused by bacteria [World Health Organization (WHO), 2020]. ESKAPE pathogens are responsible for the majority of life-threatening nosocomial infections and are capable of “escaping” the biocidal action of antimicrobial agents (Pendleton et al., 2013). The term “ESKAPE” is an acronym for six bacterial pathogens associated with multidrug resistance: Enterococcus faecium (E. faecium), Staphylococcus aureus (S. aureus), Klebsiella pneumoniae (K. pneumoniae), Acinetobacter baumannii (A. baumannii), Pseudomonas aeruginosa (P. aeruginosa), and Enterobacter spp. (Mulani et al., 2019). Multidrug-resistant (MDR) bacteria are resistant to more than one antimicrobial drug, and extensively drug-resistant (XDR) bacteria are types of drug-resistant organisms that are resistant to all, or almost all, approved antimicrobial agents (Magiorakos et al., 2012). For these reasons, it is essential to design and engineer new promising classes of antibiotics ().
The New Therapeutic Alternatives: Input From Recent Studies
As we described above, the development of antimicrobial resistance represents a major threat to public health, and this has been echoed by different health organizations around the globe. Antimicrobial peptides (AMPs) and nanoparticles (NPs) and the design of novel combinatorial therapies are among the new promising alternatives to fight infections caused by MDR- and XDR-resistant bacteria.
Antimicrobial Peptides
Antimicrobial peptides are a highly diverse family of small proteins with a varying number of amino acids; they have also been referred to as cationic host defense peptides (). A variety of synthetic AMPs have been synthesized in the laboratories, but there are also a wide diversity of AMPs produced by bacteria and yeast, in addition to those found naturally in animals and plants (Wang, 2013). AMPs have demonstrated to participate in a variety of biological activities, including as antimicrobial antiviral, antifungal, and anti-mitogenic agents, in addition to their antitumor and anti-inflammatory properties and their ability to act as immune modulators. Therefore, AMPs represent a potential alternative to replace a wide variety of commonly used drugs. Moreover, most of the available studies demonstrate that AMPs exhibit therapeutic activity in in vitro and in vivo models ().
The use of AMPs alone or in combination with conventional drugs has proven effective in combating different infectious agents, mainly MDR bacteria (Zharkova et al., 2019). AMPs are promising potential candidates to counteract multiresistant pathogens since they possess many advantages: they display potent microbicidal activity in the micromolar range (), they have demonstrated a rapid bacterial death action (Lei et al., 2019), and they have low resistance selection (Mahlapuu et al., 2016). Their mechanism of antibacterial action is multifunctional because it alters the cell membrane (Li et al., 2017) and also attacks specific targets that take part in the development of different intracellular processes (), such as inhibition of transcription, translation, protein synthesis, and bacterial cell wall formation (Mwangi et al., 2019). These general mechanisms of action of AMPs are displayed in Figure 1A.
FIGURE 1
One AMP of particular interest is human cathelicidin peptide (LL-37), which has been reported to have wound-healing effects on the host in addition to exhibiting antimicrobial and anti-biofilm activity against a variety of Gram-positive and Gram-negative human pathogens (
Colistin is another important peptide antibiotic (produced Bacillus polymyxa var. colistinus) used as a last-resort drug to treat MDR infections (Oka and Ito, 2000). It has emerged as an important agent in the treatment of Gram-negative bacterial infections, especially those caused by MDR pathogens in hospitalized patients (
The main limiting factor for the systemic use of AMPs is their sensitivity to proteolytic digestion in different body fluids (e.g., intestinal mucosa, gastrointestinal tract, and blood plasma), which directly affect both their in vivo stability and their pharmacokinetic profile (Moncla et al., 2011; Starr and Wimley, 2017). Therefore, the search for new AMPs continues, particularly in a new class of peptides with high specificity and potency, known as “selectively targeted AMPs” (STAMPs), which show increased sensitivity to specific pathogens, demonstrating a significant increase in their bactericidal capacity without direct effects on the microbiota (
Metal Nanoparticles
An additional alternative to fighting infections caused by antibiotic-resistant bacteria is the development of NPs since it has been amply reported that metal nanoparticles (MNPs) have antibacterial activity against ESKAPE pathogens (Wang et al., 2017;
Among metal oxide nanoparticles, zinc oxide (ZnO) nanoparticles have shown antimicrobial activity against both Gram-negative and Gram-positive bacteria, including Bacillus subtilis (B. subtilis), S. aureus, E. coli, P. aeruginosa, and A. baumannii (
Despite the advantages that nanoparticles offer, such as a broad therapeutic index, controlled drug release, less prone to bacterial resistance, and fewer side effects than chemical antimicrobials (
Combinatorial Treatments
The strategies to reduce antibiotic resistance include the limited use of antibiotics and the application of more effective antibacterial therapies. Because the time of exposure to antibiotics correlates with the development of resistance (
FIGURE 2

Antimicrobial treatment strategies: (A) disadvantages of using single drugs and (B) advantages of using combinatorial treatments. The advantage of using combinatorial treatments of synergistic drug pairs provides the opportunity to lower the dosage of the individual agents, thereby reducing toxicity while maintaining the wanted effect on bacteria. Moreover, a synergistic response can occur because of complementary drug action (multiple targets sites on the same protein or pathway are hit; Pemovska et al., 2018). By combining two drugs that achieve the same effect through different mechanisms of action, the development of resistance to a single drug in the combination may be less likely to occur, and when it does occur, it may have a lower impact on the therapeutic outcome (Pirrone et al., 2011). Finally, the use of more than one agent broadens the antibacterial spectrum of the empirical therapy and thus ensures that at least one agent will cover the infecting organism (
Antimicrobial Peptide-Based Combinatorial Treatments
Combinations of AMPs with antibiotics have been reported to show synergistic effects in the treatment of bacterial infections. The mechanism of antibacterial action in these combinations involves the disruption of the outer membrane (
Recent studies have demonstrated the synergistic activity of antibiotics combined with AMPs.
Metal Nanoparticle-Based Combinatorial Treatments
Metal nanoparticles should be considered as an attractive alternative to potentiate the antimicrobial effect of old and current antibiotics, since they have a high tendency to act synergistically when combined with a wide variety of antibiotics (
In the past years, there has been a marked increase in the use of biopolymers (e.g., proteins, nucleic acids, and polysaccharide) as capping agents to functionalize and stabilize MNPs (Sharma et al., 2019). Exopolysaccharides are biocompatible and eco-friendly biomolecules; therefore, they can be used in the synthesis of MNPs (
Among the most studied nanomaterials are silver nanoparticles due to their antimicrobial activity against Gram-positive and Gram-negative bacteria. They can be used in combinatorial treatments with currently used antibiotics for enhanced antimicrobial activity (Shahverdi et al., 2007;
Some other interesting studies of silver-based nanomaterials have been reported. A novel silver-microfibrillated cellulose biocomposite has been synthesized, and its antimicrobial activity was determined against relevant clinical strains. The results showed that this biocomposite has antimicrobial activity against Gram-negative and Gram-positive bacteria so that it could be applied in the development of biocompatible biomedical devices (
Moreover, a previous study showed the ability of silver to potentiate the activity of a broad range of antibiotics against Gram-negative bacteria, as well as to restore antibiotic susceptibility (re-sensitizing) to a resistant bacterial strain (Morones-Ramirez et al., 2013). Recently, a group of researchers achieved to re-sensitize antibiotic-resistant E. coli using transition-metal micronutrients (Cu2+, Zn2+, Co2+, Cd2+, and Ni2+) combined with antibiotics (ampicillin and kanamycin). These combinatorial treatments showed a therapeutic activity and no toxicological effects in a murine topical infection model caused by antibiotic-resistant strains (
The search for a new generation of antimicrobials to mitigate the spread of antibiotic resistance is urgent (
TABLE 1
| Mechanism of action | Tested bacterial strains | Advantages | Disadvantages | |
| Antimicrobial peptides (AMPs) | 1. Alteration in membrane integrity. 2. Inhibition of DNA and protein synthesis. 3. Inhibition of bacterial cell wall formation. 4. Inhibition of metabolic pathways. | Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, Enterobacter spp., multidrug-resistant strains. | 1. Show potent microbicidal activity in the micromolar range. 2. Rapid bacterial death action. 3. Low resistance selection. | 1. High sensitivity to proteolytic digestion in different body fluids. 2. Low in vivo stability. 3. Reduced pharmacokinetic profile. |
| Metal nanoparticles (MNPs) | 1. Disruption of cell membrane and increased permeability. 2. Releasing metal ions. 3. Interaction with DNA | Enterococcus faecium, Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, Escherichia coli, Salmonella typhimurium, Salmonella dysenteriae, Vibrio cholerae, Bacillus subtilis, multidrug-resistant strains. | 1. Broad therapeutic index. 2. Controlled drug release. 3. Less prone to bacterial resistance. 4. Fewer side effects than chemical antimicrobials. | 1. Need to improve metal ions release from MNPs. 2. Moderate stability in biological fluids. 3. Reduced long-term toxicity studies. |
| Combinatorial treatments | 1. Synergistic response. 2. Multiple cellular targets for antimicrobial action. 3. Combination of bactericidal and bacteriostatic mechanism of action. | Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, Escherichia coli Mycobacterium tuberculosis multidrug-resistant strains. | 1. Require lower dose than a single drug. 2. Reduced toxicity. 3. Synergisms and more effective response. 4. Decrease the probability of resistance evolution. 5. Better efficacy against multidrug-resistant bacteria. | 1. Physical-chemical compatibility among antimicrobial agents. 2. Possible pharmacokinetic and pharmacodynamic interactions. |
Antimicrobial peptides, metal nanoparticles, and combinatorial treatments: mechanism of action, tested bacterial strains, advantages, and disadvantages.
The selection of appropriate combinatorial treatment is critical for the successful prevention of infections (
Statements
Author contributions
Conceptualization, AL-B and JM-R. Writing-original draft preparation AL-B, CG-C, JG-C, JL-E, and JM-R. Graphic design, JL-E. Writing-review and editing, AL-B, CG-C, JG-C, and JM-R. Supervision, AL-B and JM-R. All authors contributed to the article and approved the submitted version.
Funding
We would like to acknowledge Paicyt 2019–2020 and 2020–2021 Science Grant from the Universidad Autónoma de Nuevo León; CONACyT Grants for Basic Science grant 221332; Fronteras de la Ciencia grant 1502; and Infraestructura Grant 279957. JG-C and JL-E were supported by Beca Nacional de Posgrado from CONACyT.
Acknowledgments
Dr. Angel Leon Buitimea would like to thank the support from Beca de Posdoctorado Nacional 2018–2020. CG-C received support from a Summer Scholarship (PROVERICyT) from the UANL.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
References
1
AkbariR.Hakemi-ValaM.PashaieF.BevalianP.HashemiA.BagheriK. P. (2019). Highly synergistic effects of melittin with conventional antibiotics against multidrug-resistant isolates of Acinetobacter baumannii and Pseudomonas aeruginosa.Microb. Drug Resist.25193–202. 10.1089/mdr.2018.0016
2
Al-MawlawiZ. S.ObaidH. H. (2019). Antibacterial activity of synergistic effect of colicin and gold nanoparticles against klebsiella pneumonia.Indian J. Public Heal. Res. Dev.10:1041. 10.5958/0976-5506.2019.00198.0
3
AnderssonD. I.BalabanN. Q.BaqueroF.CourvalinP.GlaserP.GophnaU.et al (2020). Antibiotic resistance: turning evolutionary principles into clinical reality.FEMS Microbiol. Rev.43341–361. 10.1093/femsre/fuaa001
4
AokiW.UedaM. (2013). Characterization of antimicrobial peptides toward the development of novel antibiotics.Pharmaceuticals61055–1081. 10.3390/ph6081055
5
AryaS. S.SharmaM. M.DasR. K.RookesJ.CahillD.LenkaS. K. (2019). Vanillin mediated green synthesis and application of gold nanoparticles for reversal of antimicrobial resistance in Pseudomonas aeruginosa clinical isolates.Heliyon5:e02021. 10.1016/j.heliyon.2019.e02021
6
BankierC.MatharuR. K.CheongY. K.RenG. G.Cloutman-GreenE.CiricL. (2019). Synergistic antibacterial effects of metallic nanoparticle combinations.Sci. Rep.9:16074. 10.1038/s41598-019-52473-2
7
BanoeeM.SeifS.NazariZ. E.Jafari-FesharakiP.ShahverdiH. R.MoballeghA.et al (2010). ZnO nanoparticles enhanced antibacterial activity of ciprofloxacin against Staphylococcus aureus and Escherichia coli.J. Biomed. Mater. Res. B Appl. Biomater.93557–561. 10.1002/jbm.b.31615
8
BayramovD. F.NeffJ. A. (2017). Beyond conventional antibiotics — New directions for combination products to combat biofilm.Adv. Drug Deliv. Rev.11248–60. 10.1016/j.addr.2016.07.010
9
BhandeR. M.KhobragadeC. N.ManeR. S.BhandeS. (2013). Enhanced synergism of antibiotics with zinc oxide nanoparticles against extended spectrum β-lactamase producers implicated in urinary tract infections.J. Nanoparticle Res.15:1413. 10.1007/s11051-012-1413-4
10
BoparaiJ. K.SharmaP. K. (2019). Mini review on antimicrobial peptides, sources, mechanism and recent applications.Protein Pept. Lett.264–16. 10.2174/0929866526666190822165812
11
BorthagarayG.MondelliM.FacchinG.TorreM. H. (2018). “Silver-containing nanoparticles in the research of new antimicrobial agents against ESKAPE pathogens,” in Inorganic Frameworks as Smart Nanomedicines, ed.GrumezescuA. M. (Norwich, NY: William Andrew), 317–386. 10.1016/b978-0-12-813661-4.00008-0
12
CampocciaD.MontanaroL.ArciolaC. R. (2013). A review of the biomaterials technologies for infection-resistant surfaces.Biomaterials348533–8554. 10.1016/j.biomaterials.2013.07.089
13
CassoneM.OtvosL. (2010). Synergy among antibacterial peptides and between peptides and small-molecule antibiotics.Expert Rev. Anti. Infect. Ther.8703–716. 10.1586/eri.10.38
14
ChungP. Y.KhanumR. (2017). Antimicrobial peptides as potential anti-biofilm agents against multidrug-resistant bacteria.J. Microbiol. Immunol. Infect.50405–410. 10.1016/j.jmii.2016.12.005
15
DasP.SenguptaK.GoelG.BhattacharyaS. (2017). Colistin: pharmacology, drug resistance and clinical applications.J. Acad. Clin. Microbiol.1977–85. 10.4103/jacm.jacm_31_17
16
De BreijA.RioolM.CordfunkeR. A.MalanovicN.De BoerL.KoningR. I.et al (2018). The antimicrobial peptide SAAP-148 combats drug-resistant bacteria and biofilms.Sci. Transl. Med.10:eaan4044. 10.1126/scitranslmed.aan4044
17
de DicastilloC. L.PatiñoC.GalottoM. J.Vásquez-MartínezY.TorrentC.AlburquenqueD.et al (2019). Novel hollow titanium dioxide nanospheres with antimicrobial activity against resistant bacteria.Beilstein J. Nanotechnol.101716–1725. 10.3762/bjnano.10.167
18
de la Fuente-NunezC.TorresM. D.MojicaF. J.LuT. K. (2017). Next-generation precision antimicrobials: towards personalized treatment of infectious diseases.Curr. Opin. Microbiol.3795–102. 10.1016/j.mib.2017.05.014
19
DivyashreeM.ManiM. K.ReddyD.KumavathR.GhoshP.AzevedoV.et al (2019). Clinical Applications of Antimicrobial Peptides (AMPs): where do we stand now?Protein Pept. Lett.27120–134. 10.2174/0929866526666190925152957
20
DuplantierA. J.van HoekM. L. (2013). The human cathelicidin antimicrobial peptide LL-37 as a potential treatment for polymicrobial infected wounds.Front. Immunol.4:143. 10.3389/fimmu.2013.00143
21
DürrU. H. N.SudheendraU. S.RamamoorthyA. (2006). LL-37, the only human member of the cathelicidin family of antimicrobial peptides.Biochim. Biophys. Acta Biomembr.17581408–1425. 10.1016/j.bbamem.2006.03.030
22
EbejerJ.-P.CharltonM. H.FinnP. W. (2016). Are the physicochemical properties of antibacterial compounds really different from other drugs?J. Cheminform.8:30. 10.1186/s13321-016-0143-5
23
EckertR.BradyK. M.GreenbergE. P.QiF.YarbroughD. K.HeJ.et al (2006). Enhancement of antimicrobial activity against Pseudomonas aeruginosa by coadministration of G10KHc and tobramycin.Antimicrob. Agents Chemother.503833–3838. 10.1128/AAC.00509-06
24
El-SheekhM. M.El KassasH. Y. (2014). Biosynthesis, characterization and synergistic effect of phytogenic gold nanoparticles by marine picoeukaryote Picochlorum sp. in combination with antimicrobials.Rend. Lincei.25513–521. 10.1007/s12210-014-0341-x
25
Escárcega-GonzálezC. E.Garza-CervantesJ. A.Vázquez-RodríguezA.Morones-RamírezJ. R. (2018). Bacterial exopolysaccharides as reducing and/or stabilizing agents during synthesis of metal nanoparticles with biomedical applications.Int. J. Polym. Sci.20181–15. 10.1155/2018/7045852
26
GajdácsM. (2019). The concept of an ideal antibiotic: implications for drug design.Molecules24:892. 10.3390/molecules24050892
27
Garza-CervantesJ. A.Chávez-ReyesA.CastilloE. C.García-RivasG.Ortega-RiveraO. A.SalinasE.et al (2017). Synergistic antimicrobial effects of silver/transition-metal combinatorial treatments.Sci. Rep.71–16. 10.1038/s41598-017-01017-7
28
Garza-CervantesJ. A.Escárcega-GonzálezC. E.Barriga CastroE. D.Mendiola-GarzaG.Marichal-CancinoB. A.López-VázquezM. A.et al (2019). Antimicrobial and antibiofilm activity of biopolymer-Ni, Zn nanoparticle biocomposites synthesized using R. mucilaginosa UANL-001L exopolysaccharide as a capping agent.Int. J. Nanomed.142557–2571. 10.2147/IJN.S196470
29
Garza-CervantesJ. A.Mendiola-GarzaG.de MeloE. M.DugmoreT. I. J.MatharuA. S.Morones-RamirezJ. R. (2020a). Antimicrobial activity of a silver-microfibrillated cellulose biocomposite against susceptible and resistant bacteria.Sci. Rep.10:7281. 10.1038/s41598-020-64127-9
30
Garza-CervantesJ. A.Meza-BustillosJ. F.Resendiz-HernandezH.Suarez-CantúI. A.Ortega-RiveraO. A.SalinasE.et al (2020b). Re-sensitizing ampicillin and kanamycin-resistant E. coli and S. aureus using synergistic metal micronutrients-antibiotic combinations.Front. Bioeng. Biotechnol.8:612. 10.3389/FBIOE.2020.00612
31
GeloverS.GómezL. A.ReyesK.Teresa LealM. (2006). A practical demonstration of water disinfection using TiO2 films and sunlight.Water Res.403274–3280. 10.1016/j.watres.2006.07.006
32
GuoB. L.HanP.GuoL. C.CaoY. Q.LiA. D.KongJ. Z.et al (2015). The antibacterial activity of Ta-doped ZnO nanoparticles.Nanoscale Res. Lett.10:336. 10.1186/s11671-015-1047-4
33
GurjarM.AzimA.BaroniaA.AhmedA. (2014). Current concepts in combination antibiotic therapy for critically ill patients.Indian J. Crit. Care Med.18310–314. 10.4103/0972-5229.132495
34
HeJ.AndersonM. H.ShiW.EckertR. (2009). Design and activity of a ‘dual-targeted’ antimicrobial peptide.Int. J. Antimicrob. Agents33532–537. 10.1016/j.ijantimicag.2008.11.013
35
HuoL.HuangX.LingJ.LiuH.LiuJ. (2017). Selective activities of STAMPs against Streptococcus mutans.Exp. Ther. Med.151886–1893. 10.3892/etm.2017.5631
36
JacksonN.CzaplewskiL.PiddockL. J. V. (2018). Discovery and development of new antibacterial drugs: learning from experience?J. Antimicrob. Chemother.731452–1459. 10.1093/jac/dky019
37
JeslineA.JohnN. P.NarayananP. M.VaniC.MuruganS. (2015). Antimicrobial activity of zinc and titanium dioxide nanoparticles against biofilm-producing methicillin-resistant Staphylococcus aureus.Appl. Nanosci.5157–162. 10.1007/s13204-014-0301-x
38
KalitaS.KandimallaR.SharmaK. K.KatakiA. C.DekaM.KotokyJ. (2016). Amoxicillin functionalized gold nanoparticles reverts MRSA resistance.Mater. Sci. Eng. C61720–727. 10.1016/j.msec.2015.12.078
39
KhuranaC.SharmaP.PandeyO. P.ChudasamaB. (2016). Synergistic effect of metal nanoparticles on the antimicrobial activities of antibiotics against biorecycling microbes.J. Mater. Sci. Technol.32524–532. 10.1016/j.jmst.2016.02.004
40
KoppenB. C.MulderP. P. G.de BoerL.RioolM.DrijfhoutJ. W.ZaatS. A. J. (2019). Synergistic microbicidal effect of cationic antimicrobial peptides and teicoplanin against planktonic and biofilm-encased Staphylococcus aureus.Int. J. Antimicrob. Agents53143–151. 10.1016/j.ijantimicag.2018.10.002
41
KoraA. J.RastogiL. (2013). Enhancement of antibacterial activity of capped silver nanoparticles in combination with antibiotics, on model gram-negative and gram-positive bacteria.Bioinorg. Chem. Appl.2013:871097. 10.1155/2013/871097
42
KościuczukE. M.LisowskiP.JarczakJ.StrzałkowskaN.JóźwikA.HorbañczukJ.et al (2012). Cathelicidins: family of antimicrobial peptides. A review.Mol. Biol. Rep.3910957–10970. 10.1007/s11033-012-1997-x
43
KrauseK. M.SerioA. W.KaneT. R.ConnollyL. E. (2016). Aminoglycosides: an Overview.Cold Spring Harb. Perspect. Med.6:a027029. 10.1101/cshperspect.a027029
44
KumarR.ShuklaS. K.PandeyM.PandeyA.PathakA.DikshitA. (2016). Synthesis and antimicrobial effects of colloidal gold nanoparticles against prevalent waterborne bacterial pathogens.Cogent Chem.2:1192522. 10.1080/23312009.2016.1192522
45
LeC. F.FangC. M.SekaranS. D. (2017). Intracellular targeting mechanisms by antimicrobial peptides.Antimicrob. Agents Chemother.61:e02340-16. 10.1128/AAC.02340-16
46
LeeB.LeeD. G. (2019). Synergistic antibacterial activity of gold nanoparticles caused by apoptosis-like death.J. Appl. Microbiol.127701–712. 10.1111/jam.14357
47
LeeN.-Y.KoW.-C.HsuehP.-R. (2019). Nanoparticles in the treatment of infections caused by multidrug-resistant organisms.Front. Pharmacol.10:1153. 10.3389/fphar.2019.01153
48
LehárJ.KruegerA. S.AveryW.HeilbutA. M.JohansenL. M.PriceE. R.et al (2009). Synergistic drug combinations tend to improve therapeutically relevant selectivity.Nat. Biotechnol.27659–666. 10.1038/nbt.1549
49
LeiJ.SunL.HuangS.ZhuC.LiP.HeJ.et al (2019). The antimicrobial peptides and their potential clinical applications.Am. J. Transl. Res.113919–3931.
50
LiJ.KohJ. J.LiuS.LakshminarayananR.VermaC. S.BeuermanR. W. (2017). Membrane active antimicrobial peptides: translating mechanistic insights to design.Front. Neurosci.11:73. 10.3389/fnins.2017.00073
51
Lopez-CarrizalesM.VelascoK. I.CastilloC.FloresA.MagañaM.Martinez-CastanonG. A.et al (2018). In vitro synergism of silver nanoparticles with antibiotics as an alternative treatment in multiresistant uropathogens.Antibiotics7:50. 10.3390/antibiotics7020050
52
MagiorakosA. P.SrinivasanA.CareyR. B.CarmeliY.FalagasM. E.GiskeC. G.et al (2012). Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance.Clin. Microbiol. Infect.18268–281. 10.1111/j.1469-0691.2011.03570.x
53
MahlapuuM.HåkanssonJ.RingstadL.BjörnC. (2016). Antimicrobial peptides: an emerging category of therapeutic agents.Front. Cell. Infect. Microbiol.6:194. 10.3389/fcimb.2016.00194
54
MantravadiH. B. (2017). Effectivity of titanium oxide based nano particles on E. coli from clinical samples.J. Clin. Diagnostic Res.11DC37–DC40. 10.7860/JCDR/2017/25334.10278
55
MaoR.TengD.WangX.XiD.ZhangY.HuX.et al (2013). Design, expression, and characterization of a novel targeted plectasin against methicillin-resistant Staphylococcus aureus.Appl. Microbiol. Biotechnol.973991–4002. 10.1007/s00253-012-4508-z
56
MarksL. R.ClementiE. A.HakanssonA. P. (2013). Sensitization of Staphylococcus aureus to methicillin and other antibiotics in vitro and in vivo in the presence of HAMLET.PLoS One8:e63158. 10.1371/journal.pone.0063158
57
MonclaB. J.PrykeK.RohanL. C.GraebingP. W. (2011). Degradation of naturally occurring and engineered antimicrobial peptides by proteases.Adv. Biosci. Biotechnol.02404–408. 10.4236/abb.2011.26059
58
Montelongo-PeraltaL. Z.León-BuitimeaA.Palma-NicolásJ. P.Gonzalez-ChristenJ.Morones-RamírezJ. R. (2019). Antibacterial Activity of combinatorial treatments composed of transition-metal/antibiotics against Mycobacterium tuberculosis.Sci. Rep.9:5471. 10.1038/s41598-019-42049-5
59
MoronesJ. R.Luis ElechiguerraJ.CamachoA.HoltK.KouriJ. B.Tapia RamírezJ.et al (2005). The bactericidal effect of silver nanoparticles.Inst. Phys. Publ. Nanotechnol. Nanotechnol.162346–2353. 10.1088/0957-4484/16/10/059
60
Morones-RamirezJ. R.WinklerJ. A.SpinaC. S.CollinsJ. J. (2013). Silver enhances antibiotic activity against gram-negative bacteria.Sci. Transl. Med.5:190ra81. 10.1126/scitranslmed.3006276
61
MulaniM. S.KambleE. E.KumkarS. N.TawreM. S.PardesiK. R. (2019). Emerging strategies to combat ESKAPE pathogens in the era of antimicrobial resistance: a review.Front. Microbiol.10:539. 10.3389/fmicb.2019.00539
62
MuruganS. (2018). Investigation of the synergistic antibacterial action of copper nanoparticles on certain antibiotics against human pathogens.Int. J. Pharm. Pharm. Sci.1083–86. 10.22159/ijpps.2018v10i10.28069
63
MwangiJ.HaoX.LaiR.ZhangZ. (2019). Antimicrobial peptides: new hope in the war against multidrug resistance.Zool. Res.40488–505. 10.24272/j.issn.2095-8137.2019.062
64
NaqviS. Z. H.KiranU.AliM. I.JamalA.HameedA.AhmedS.et al (2013). Combined efficacy of biologically synthesized silver nanoparticles and different antibiotics against multidrug-resistant bacteria.Int. J. Nanomed.83187–3195. 10.2147/IJN.S49284
65
NishanthiR.MalathiS.JohnP. S.PalaniP. (2019). Green synthesis and characterization of bioinspired silver, gold and platinum nanoparticles and evaluation of their synergistic antibacterial activity after combining with different classes of antibiotics.Mater. Sci. Eng. C96693–707. 10.1016/j.msec.2018.11.050
66
OkaH.ItoY. (2000). “ANTIBIOTICS | High-Speed Countercurrent Chromatography,” in Encyclopedia of Separation Science, edsAdlardE. R.IWilsonD.PooleC. F.CookeM. (Amsterdam: Elsevier), 2058–2067. 10.1016/b0-12-226770-2/03311-1
67
PanácekA.SmékalováM.KilianováM.PrucekR.BogdanováK.VěcěrováR.et al (2016). Strong and nonspecific synergistic antibacterial efficiency of antibiotics combined with silver nanoparticles at very low concentrations showing no cytotoxic effect.Molecules21:26. 10.3390/molecules21010026
68
PemovskaT.BigenzahnJ. W.Superti-FurgaG. (2018). Recent advances in combinatorial drug screening and synergy scoring.Curr. Opin. Pharmacol.42102–110. 10.1016/j.coph.2018.07.008
69
PendletonJ. N.GormanS. P.GilmoreB. F. (2013). Clinical relevance of the ESKAPE pathogens.Expert Rev. Anti. Infect. Ther.11297–308. 10.1586/eri.13.12
70
PerveenS.SafdarN.ChaudhryG. E.YasminA. (2018). Antibacterial evaluation of silver nanoparticles synthesized from lychee peel: individual versus antibiotic conjugated effects.World J. Microbiol. Biotechnol.34:118. 10.1007/s11274-018-2500-1
71
PirroneV.ThakkarN.JacobsonJ. M.WigdahlB.KrebsF. C. (2011). Combinatorial approaches to the prevention and treatment of HIV-1 infection.Antimicrob. Agents Chemother.551831–1842. 10.1128/AAC.00976-10
72
PrestonS. L. (2004). The importance of appropriate antimicrobial dosing: pharmacokinetic and pharmacodynamic considerations.Ann. Pharmacother.38(9 Suppl.), S14–S18. 10.1345/aph.1E218
73
RoutG. K.ShinH.-S.GoudaS.SahooS.DasG.FracetoL. F.et al (2018). Current advances in nanocarriers for biomedical research and their applications.Artif. Cells Nanomed. Biotechnol.461053–1062. 10.1080/21691401.2018.1478843
74
RudenS.RiederA.Chis SterI.SchwartzT.MikutR.HilpertK. (2019). Synergy pattern of short cationic antimicrobial peptides against multidrug-resistant Pseudomonas aeruginosa.Front. Microbiol.10:2740. 10.3389/fmicb.2019.02740
75
SarmaP.MahendirattaS.PrakashA.MedhiB. (2018). Specifically targeted antimicrobial peptides: a new and promising avenue in selective antimicrobial therapy.Indian J. Pharmacol.50:1. 10.4103/ijp.IJP_218_18
76
SelvarajR. C. A.RajendranM.NagaiahH. P. (2019). Re-potentiation of β-lactam antibiotic by synergistic combination with biogenic copper oxide nanocubes against biofilm forming multidrug-resistant bacteria.Molecules24:3055. 10.3390/molecules24173055
77
ShahverdiA. R.FakhimiA.ShahverdiH. R.MinaianS. (2007). Synthesis and effect of silver nanoparticles on the antibacterial activity of different antibiotics against Staphylococcus aureus and Escherichia coli.Nanomed. Nanotechnol. Biol. Med.3168–171. 10.1016/j.nano.2007.02.001
78
ShaikhS.NazamN.RizviS. M. D.AhmadK.BaigM. H.LeeE. J.et al (2019). Mechanistic insights into the antimicrobial actions of metallic nanoparticles and their implications for multidrug resistance.Int. J. Mol. Sci.20:2468. 10.3390/ijms20102468
79
SharmaD.KanchiS.BisettyK. (2019). Biogenic synthesis of nanoparticles: a review.Arab. J. Chem.123576–3600. 10.1016/j.arabjc.2015.11.002
80
SiZ.LimH. W.TayM. Y. F.DuY.RuanL.QiuH.et al (2020). A glycosylated cationic block poly(beta-peptide) reverses intrinsic antibiotic resistance in all ESKAPE Gram-negative bacteria.Angew. Chemie Int. Ed.596819–6826. 10.1002/anie.201914304
81
SinghR.WaghP.WadhwaniS.GaidhaniS.KumbharA.BellareJ.et al (2013). Synthesis, optimization, and characterization of silver nanoparticles from Acinetobacter calcoaceticus and their enhanced antibacterial activity when combined with antibiotics.Int. J. Nanomed.84277–4290. 10.2147/IJN.S48913
82
StarrC. G.WimleyW. C. (2017). Antimicrobial peptides are degraded by the cytosolic proteases of human erythrocytes.Biochim. Biophys. Acta Biomembr.18592319–2326. 10.1016/j.bbamem.2017.09.008
83
TammaP. D.CosgroveS. E.MaragakisL. L. (2012). Combination therapy for treatment of infections with gram-negative bacteria.Clin. Microbiol. Rev.25450–470. 10.1128/CMR.05041-11
84
TiwariV.MishraN.GadaniK.SolankiP. S.ShahN. A.TiwariM. (2018). Mechanism of anti-bacterial activity of zinc oxide nanoparticle against carbapenem-resistant Acinetobacter baumannii.Front. Microbiol.9:1218. 10.3389/fmicb.2018.01218
85
van der WeideH.Vermeulen-de JonghD. M. C.van der MeijdenA.BoersS. A.KreftD.ten KateM. T.et al (2019). Antimicrobial activity of two novel antimicrobial peptides AA139 and SET-M33 against clinically and genotypically diverse Klebsiella pneumoniae isolates with differing antibiotic resistance profiles.Int. J. Antimicrob. Agents54159–166. 10.1016/j.ijantimicag.2019.05.019
86
Vazquez-MuñozR.Meza-VillezcasA.FournierP. G. J.Soria-CastroE.Juarez-MorenoK.Gallego-HernándezA. L.et al (2019). Enhancement of antibiotics antimicrobial activity due to the silver nanoparticles impact on the cell membrane.PLoS One14:e0224904. 10.1371/journal.pone.0224904
87
Vazquez-RodriguezA.Vasto-AnzaldoX.Leon-BuitimeaA.ZarateX.Morones-RamirezJ. R. (2020). Antibacterial and antibiofilm activity of biosynthesized silver nanoparticles coated with exopolysaccharides obtained from Rhodotorula mucilaginosa.IEEE Trans. Nanobioscience19498–503. 10.1109/TNB.2020.2985101
88
WangG. (2013). Database-guided discovery of potent peptides to combat HIV-1 or superbugs.Pharmaceuticals6728–758. 10.3390/ph6060728
89
WangL.HuC.ShaoL. (2017). The antimicrobial activity of nanoparticles: present situation and prospects for the future.Int. J. Nanomedicine121227–1249. 10.2147/IJN.S121956
90
World Health Organization (WHO) (2020). Antibiotic Resistance. Available online at: https://www.who.int/news-room/fact-sheets/detail/antibiotic-resistance(accessed January 13, 2020).
91
WolframJ.ZhuM.YangY.ShenJ.GentileE.PaolinoD.et al (2015). Safety of nanoparticles in medicine.Curr. Drug Targets161671–1681. 10.2174/1389450115666140804124808
92
Woźniak-BudychM. J.PrzysieckaŁLangerK.PepliñskaB.JarekM.WiesnerM.et al (2017). Green synthesis of rifampicin-loaded copper nanoparticles with enhanced antimicrobial activity.J. Mater. Sci. Mater. Med.28:42. 10.1007/s10856-017-5857-z
93
WuP.GraingerD. W. (2006). Drug/device combinations for local drug therapies and infection prophylaxis.Biomaterials272450–2467. 10.1016/j.biomaterials.2005.11.031
94
XuL.ShaoC.LiG.ShanA.ChouS.WangJ.et al (2020). Conversion of broad-spectrum antimicrobial peptides into species-specific antimicrobials capable of precisely targeting pathogenic bacteria.Sci. Rep.10:944. 10.1038/s41598-020-58014-6
95
YangP.PageniP.RahmanM. A.BamM.ZhuT.ChenY. P.et al (2019). Gold nanoparticles with antibiotic-metallopolymers toward broad-spectrum antibacterial effects.Adv. Healthc. Mater.8:e1800854. 10.1002/adhm.201800854
96
ZhangY.BaiY.JiaJ.GaoN.LiY.ZhangR.et al (2014). Perturbation of physiological systems by nanoparticles.Chem. Soc. Rev.433762–3809. 10.1039/c3cs60338e
97
ZharkovaM. S.OrlovD. S.GolubevaO. Y.ChakchirO. B.EliseevI. E.GrinchukT. M.et al (2019). Application of antimicrobial peptides of the innate immune system in combination with conventional antibiotics-a novel way to combat antibiotic resistance?Front. Cell. Infect. Microbiol.9:128. 10.3389/fcimb.2019.00128
Summary
Keywords
ESKAPE, MDR, XDR, antimicrobial peptides, metal nanoparticles, combinatorial treatments
Citation
León-Buitimea A, Garza-Cárdenas CR, Garza-Cervantes JA, Lerma-Escalera JA and Morones-Ramírez JR (2020) The Demand for New Antibiotics: Antimicrobial Peptides, Nanoparticles, and Combinatorial Therapies as Future Strategies in Antibacterial Agent Design. Front. Microbiol. 11:1669. doi: 10.3389/fmicb.2020.01669
Received
11 April 2020
Accepted
25 June 2020
Published
24 July 2020
Volume
11 - 2020
Edited by
Hemda Garelick, Middlesex University, United Kingdom
Reviewed by
Lilit Tonoyan, National University of Ireland Galway, Ireland; Maria José Saavedra, Universidade de Trás-os-Montes e Alto Douro, Portugal
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© 2020 León-Buitimea, Garza-Cárdenas, Garza-Cervantes, Lerma-Escalera and Morones-Ramírez.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Jose R. Morones-Ramírez, jose.moronesrmr@uanl.edu.mx
†These authors have contributed equally to this work
This article was submitted to Antimicrobials, Resistance and Chemotherapy, a section of the journal Frontiers in Microbiology
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