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Liu M, Cheng JH, Zhao H, Yu C, Wu J. Targeting the outer membrane of gram-negative foodborne pathogens for food safety: compositions, functions, and disruption strategies. Crit Rev Food Sci Nutr 2024:1-14. [PMID: 39213149 DOI: 10.1080/10408398.2024.2397462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Foodborne pathogens are a major threat to both food safety and public health. The current trend toward fresh and less processed foods and the misuse of antibiotics in food production have made controlling these pathogens even more challenging. The outer membrane has been employed as a practical target to combat foodborne Gram-negative pathogens due to its accessibility and importance. In this review, the compositions of the outer membrane are extensively described firstly, to offer a thorough overview of this target. Current strategies for disrupting the outer membrane are also discussed, with emphasized on their mechanism of action. The disruption of the outer membrane structure, whether caused by severe damage of the lipid bilayer or by interference with the biosynthesis pathway, has been demonstrated to represent an effective antimicrobial strategy. Interference with the outer membrane-mediated functions of barrier, efflux and adhesion also contributes to the fight against Gram-negative pathogens. Their potential for control of foodborne pathogens in the production chain are also proposed. However, it is possible that multiple components in the food matrix may act as a protective barrier against microorganisms, and it is often the case that contamination is not caused by a single microorganism. Further investigation is needed to determine the effectiveness and safety of these methods in more complex systems, and it may be advisable to consider a multi-technology combined approach. Additionally, further studies on outer membranes are necessary to discover more promising mechanisms of action.
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Affiliation(s)
- Mengyuan Liu
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou, China
| | - Jun-Hu Cheng
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou, China
| | - Haigang Zhao
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- ChemPartner PharmaTech Co., Ltd., Jiangmen, China
| | - Chongchong Yu
- Beijing Key Laboratory of Big Data Technology for Food Safety, Beijing Technology and Business University, Beijing, China
| | - Jingzhu Wu
- Beijing Key Laboratory of Big Data Technology for Food Safety, Beijing Technology and Business University, Beijing, China
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2
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Romero J, Blas-Chumacero S, Urzúa V, Villasante A, Opazo R, Gajardo F, Miranda CD, Rojas R. Lysin and Lytic Phages Reduce Vibrio Counts in Live Feed and Fish Larvae. Microorganisms 2024; 12:904. [PMID: 38792735 PMCID: PMC11123823 DOI: 10.3390/microorganisms12050904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 03/19/2024] [Accepted: 03/26/2024] [Indexed: 05/26/2024] Open
Abstract
Vibrio species are naturally found in estuarine and marine ecosystems, but are also recognized as significant human enteropathogens, often linked to seafood-related illnesses. In aquaculture settings, Vibrio poses a substantial risk of infectious diseases, resulting in considerable stock losses and prompting the use of antimicrobials. However, this practice contributes to the proliferation of antimicrobial-resistant (AMR) bacteria and resistance genes. Our investigation aimed to explore the potential of biological agents such as bacteriophage CH20 and endolysin LysVPp1 in reducing Vibrio bacterial loads in both rotifer and fish larvae. LysVPp1's lytic activity was assessed by measuring absorbance reduction against various pathogenic Vibrio strains. Phage CH20 exhibited a limited host range, affecting only Vibrio alginolyticus GV09, a highly pathogenic strain. Both CH20 and LysVPp1 were evaluated for their effectiveness in reducing Vibrio load in rotifers or fish larvae through short-setting bioassays. Our results demonstrated the significant lytic effect of endolysin LysVPp1 on strains of Vibrio alginolyticus, Vibrio parahaemolyticus, and Vibrio splendidus. Furthermore, we have showcased the feasibility of reducing the load of pathogenic Vibrio in live feed and fish larvae by using a non-antibiotic-based approach, such as lytic phage and endolysin LysVPp1, thus contributing to the progress of a sustainable aquaculture from a One Health perspective.
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Affiliation(s)
- Jaime Romero
- Laboratorio de Biotecnología de Alimentos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago 7830489, Chile; (S.B.-C.); (V.U.); (A.V.); (R.O.); (F.G.)
| | - Sergueia Blas-Chumacero
- Laboratorio de Biotecnología de Alimentos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago 7830489, Chile; (S.B.-C.); (V.U.); (A.V.); (R.O.); (F.G.)
| | - Victoria Urzúa
- Laboratorio de Biotecnología de Alimentos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago 7830489, Chile; (S.B.-C.); (V.U.); (A.V.); (R.O.); (F.G.)
| | - Alejandro Villasante
- Laboratorio de Biotecnología de Alimentos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago 7830489, Chile; (S.B.-C.); (V.U.); (A.V.); (R.O.); (F.G.)
| | - Rafael Opazo
- Laboratorio de Biotecnología de Alimentos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago 7830489, Chile; (S.B.-C.); (V.U.); (A.V.); (R.O.); (F.G.)
| | - Felipe Gajardo
- Laboratorio de Biotecnología de Alimentos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, El Líbano 5524, Santiago 7830489, Chile; (S.B.-C.); (V.U.); (A.V.); (R.O.); (F.G.)
| | - Claudio D. Miranda
- Laboratorio de Patobiología Acuática, Departamento de Acuicultura, Universidad Católica del Norte, Larrondo 1281, Coquimbo 1780000, Chile; (C.D.M.); (R.R.)
| | - Rodrigo Rojas
- Laboratorio de Patobiología Acuática, Departamento de Acuicultura, Universidad Católica del Norte, Larrondo 1281, Coquimbo 1780000, Chile; (C.D.M.); (R.R.)
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3
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Dinu LD, Al-Zaidi QJ, Matache AG, Matei F. Improving the Efficiency of Viability-qPCR with Lactic Acid Enhancer for the Selective Detection of Live Pathogens in Foods. Foods 2024; 13:1021. [PMID: 38611327 PMCID: PMC11012224 DOI: 10.3390/foods13071021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 03/22/2024] [Accepted: 03/25/2024] [Indexed: 04/14/2024] Open
Abstract
Pathogenic Escherichia coli are the most prevalent foodborne bacteria, and their accurate detection in food samples is critical for ensuring food safety. Therefore, a quick technique named viability-qPCR (v-qPCR), which is based on the ability of a selective dye, such as propidium monoazide (PMA), to differentiate between alive and dead cells, has been developed. Despite diverse, successful applications, v-qPCR is impaired by some practical limitations, including the ability of PMA to penetrate the outer membrane of dead Gram-negative bacteria. The objective of this study is to evaluate the ability of lactic acid (LA) to improve PMA penetration and, thus, the efficiency of v-qPCR in detecting the live fraction of pathogens. The pre-treatment of E. coli ATCC 8739 cells with 10 mM LA greatly increased PMA penetration into dead cells compared to conventional PMA-qPCR assay, avoiding false positive results. The limit of detection when using LA-PMA qPCR is 1% viable cells in a mixture of dead and alive cells. The optimized LA-PMA qPCR method was reliably able to detect log 2 CFU/mL culturable E. coli in milk spiked with viable and non-viable bacteria. Lactic acid is cheap, has low toxicity, and can be used to improve the efficiency of the v-qPCR assay, which is economically interesting for larger-scale pathogen detection applications intended for food matrices.
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Affiliation(s)
- Laura-Dorina Dinu
- Faculty of Biotechnology, University of Agricultural Sciences and Veterinary Medicine, 011464 Bucharest, Romania; (Q.J.A.-Z.); (A.G.M.); (F.M.)
| | - Quthama Jasim Al-Zaidi
- Faculty of Biotechnology, University of Agricultural Sciences and Veterinary Medicine, 011464 Bucharest, Romania; (Q.J.A.-Z.); (A.G.M.); (F.M.)
| | - Adelina Georgiana Matache
- Faculty of Biotechnology, University of Agricultural Sciences and Veterinary Medicine, 011464 Bucharest, Romania; (Q.J.A.-Z.); (A.G.M.); (F.M.)
| | - Florentina Matei
- Faculty of Biotechnology, University of Agricultural Sciences and Veterinary Medicine, 011464 Bucharest, Romania; (Q.J.A.-Z.); (A.G.M.); (F.M.)
- Faculty of Food Industry and Tourism, Transilvania University of Brasov, 500015 Brasov, Romania
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4
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Paterson JR, Wadsworth JM, Hu P, Sharples GJ. A critical role for iron and zinc homeostatic systems in the evolutionary adaptation of Escherichia coli to metal restriction. Microb Genom 2023; 9:001153. [PMID: 38054971 PMCID: PMC10763504 DOI: 10.1099/mgen.0.001153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/23/2023] [Indexed: 12/07/2023] Open
Abstract
Host nutritional immunity utilizes metal deprivation to help prevent microbial infection. To investigate bacterial adaptation to such restrictive conditions, we conducted experimental evolution with two metal sequestering agents. Ethylenediaminetetraacetic acid (EDTA) and diethylenetriamine pentamethylene phosphonic acid (DTPMP) were selected as ligands because they differentially affect cellular levels of iron, manganese and zinc in Escherichia coli. Mutants of E. coli strain BW25113 were isolated after cultivation at sub-minimum inhibitory concentration (MIC) chelant levels and genetic changes potentially responsible for tolerance were identified by whole-genome sequencing. In EDTA-selected strains, mutations in the promoter region of yeiR resulted in elevated gene expression. The yeiR product, a zinc-specific metallochaperone, was confirmed to be primarily responsible for EDTA resistance. Similarly, in two of the DTPMP-selected strains, a promoter mutation increased expression of the fepA-entD operon, which encodes components of the ferric-enterobactin uptake pathway. However, in this case improved DTPMP tolerance was only detectable following overexpression of FepA or EntD in trans. Additional mutations in the cadC gene product, an acid-response regulator, preserved the neutrality of the growth medium by constitutively activating expression of the cadAB regulon. This study uncovers specific resistance mechanisms for zinc and iron starvation that could emerge by selection against host nutritional immunity or competition with heterologous metallophores. It also provides insight into the specific metals affected by these two widely used chelators critical for their antibacterial mode of action.
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Affiliation(s)
| | | | - Ping Hu
- Procter and Gamble, Mason Business Center, Cincinnati, Ohio 45040, USA
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5
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Jeffs MA, Gray RAV, Sheth PM, Lohans CT. Development of a whole-cell biosensor for β-lactamase inhibitor discovery. Chem Commun (Camb) 2023; 59:12707-12710. [PMID: 37801331 DOI: 10.1039/d3cc03583b] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/07/2023]
Abstract
The production of β-lactamases by bacterial pathogens endangers antimicrobial therapy, and new inhibitors for β-lactamases are urgently needed. We report the development of a luminescent-based biosensor that quantifies β-lactamase inhibition in a cellular context, based on the activation of transcriptional factor AmpR following the exposure of bacterial cells to β-lactams. This rapid method can account for factors like membrane permeability and can be employed to identify new β-lactamase inhibitors.
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Affiliation(s)
- Mitchell A Jeffs
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada.
| | - Rachel A V Gray
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada.
| | - Prameet M Sheth
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada.
- Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada
| | - Christopher T Lohans
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada.
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Latoch A, Czarniecka-Skubina E, Moczkowska-Wyrwisz M. Marinades Based on Natural Ingredients as a Way to Improve the Quality and Shelf Life of Meat: A Review. Foods 2023; 12:3638. [PMID: 37835291 PMCID: PMC10572579 DOI: 10.3390/foods12193638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 09/28/2023] [Accepted: 09/28/2023] [Indexed: 10/15/2023] Open
Abstract
Marinating is a traditional method of improving the quality of meat, but it has been modified in response to consumer demand for "clean label" products. The aim of this review is to present scientific literature on the natural ingredients contained in marinades, the parameters of the marinating process, and certain mechanisms that bring about changes in meat. A review was carried out of publications from 2000 to 2023 available in Web of Science on the natural ingredients of meat marinades: fruit and vegetables, seasonings, fermented dairy products, wine, and beer. The review showed that natural marinades improve the sensory quality of meat and its culinary properties; they also extend its shelf life. They affect the safety of meat products by limiting the oxidation of fats and proteins. They also reduce biogenic amines and the formation of heterocyclic aromatic amines (HAAs) and polycyclic aromatic hydrocarbons (PAHs). This is possible due to the presence of biologically active substances and competitive microflora from dairy products. However, some marinades, especially those that are acidic, cause a slightly acidic flavour and an unfavourable colour change. Natural compounds in the ingredients of marinades are accepted by consumers. There are no results in the literature on the impact of natural marinades on the nutritional value and health-promoting potential of meat products, so it can be assumed that this is a future direction for scientific research.
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Affiliation(s)
- Agnieszka Latoch
- Department of Animal Food Technology, University of Life Sciences in Lublin, 8 Skromna St., 20-704 Lublin, Poland;
| | - Ewa Czarniecka-Skubina
- Department of Food Gastronomy and Food Hygiene, Institute of Human Nutrition Sciences, Warsaw University of Life Sciences (WULS), 166 Nowoursynowska St., 02-787 Warsaw, Poland;
| | - Małgorzata Moczkowska-Wyrwisz
- Department of Food Gastronomy and Food Hygiene, Institute of Human Nutrition Sciences, Warsaw University of Life Sciences (WULS), 166 Nowoursynowska St., 02-787 Warsaw, Poland;
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7
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Widsten P, Salo S, Niemelä K, Helin H, Salonen M, Alakomi HL. Tannin-Based Microbicidal Coatings for Hospital Privacy Curtains. J Funct Biomater 2023; 14:jfb14040187. [PMID: 37103276 PMCID: PMC10144558 DOI: 10.3390/jfb14040187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/20/2023] [Accepted: 03/21/2023] [Indexed: 03/30/2023] Open
Abstract
The goal of this study was to develop a sustainable, tannin-based option for silver-based and other current antimicrobial solutions for hospital privacy curtains. Commercial tree-derived tannins were characterized and their in vitro antibacterial properties against Staphylococcus aureus and Escherichia coli were determined. Hydrolysable tannins showed greater antibacterial efficacy than condensed tannins but differences in antibacterial efficacy between any of the tannins could not be attributed to their functional group content or molar mass. Outer membrane disruption was not a significant factor in antibacterial efficacy of tannins against E. coli. In a hospital field study, draw patches coated with hydrolysable tannins and affixed to privacy curtains reduced total bacteria count by 60% over eight weeks compared to their matching uncoated reference sides. In a follow-up laboratory study with S. aureus, very light spraying with water improved contact between bacteria and coating, enhancing the antibacterial effect by several orders of magnitude.
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Affiliation(s)
- Petri Widsten
- VTT Technical Research Centre of Finland Ltd., Tietotie 2, 02150 Espoo, Finland
- Correspondence:
| | - Satu Salo
- VTT Technical Research Centre of Finland Ltd., Tietotie 2, 02150 Espoo, Finland
| | - Klaus Niemelä
- VTT Technical Research Centre of Finland Ltd., Tietotie 2, 02150 Espoo, Finland
| | - Hanna Helin
- FIMLAB Laboratoriot Ltd., Arvo Ylpön katu 4, 33520 Tampere, Finland
| | - Minna Salonen
- Hospital Nova of Central Finland, The Central Finland Health Care District Consortium, Hoitajantie 3, 40620 Jyväskylä, Finland
| | - Hanna-Leena Alakomi
- VTT Technical Research Centre of Finland Ltd., Tietotie 2, 02150 Espoo, Finland
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8
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The design of cell-selective tryptophan and arginine-rich antimicrobial peptides by introducing hydrophilic uncharged residues. Acta Biomater 2022; 153:557-572. [PMID: 36115654 DOI: 10.1016/j.actbio.2022.09.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Revised: 08/18/2022] [Accepted: 09/09/2022] [Indexed: 11/20/2022]
Abstract
Antimicrobial peptides (AMPs) are considered to be powerful weapons in the fight against traditional antibiotic resistance due to their unique membrane-disruptive mechanism. The combination of traditional and classical hydrophobic tryptophan (W) residues and hydrophilic charged arginine (R) residues is considered as the first choice for the minimalist design of AMPs due to its potent performance in antibacterial activity. However, some W- and R-rich AMPs that are not rationally designed and contain excessive repeats of W and R residues may cause severe cytotoxicity and hemolysis. To address this issue, we designed the (WRX)n (where X = hydrophilic uncharged amino residues; n = number of repeat units) series engineered peptides with high cell selectivity by introducing hydrophilic uncharged threonine (T), serine (S), glutamine (Q) or asparagine (N) residues into the minimalist design of W- and R-rich AMPs. The results showed that the introduction of these hydrophilic uncharged amino residues, especially T residues, significantly improved the cell selectivity of the W- and R-rich engineered peptides. Among (WRX)n series engineered peptides, T6 presents a mixture structure of β-turn and α-helix. It has broad spectrum and potent antibacterial activity (no activity against probiotics), good biocompatibility, high selectivity index, strong tolerance (physiological salts, serum acid, alkali, and heat conditions), rapid and efficient time-kill kinetics, and no tendency of resistance. Studies on antibacterial mechanism show that T6 exert antibacterial activity mainly by disrupting bacterial cell membrane and inducing the accumulation of reactive oxygen species in bacterial cells. Furthermore, T6 exhibited potent antibacterial and anti-inflammatory capabilities in vivo in a mouse peritonitis-sepsis model infected with Escherichia coli. In conclusion, our study confirms an effective strategy for the minimalist design of highly cell selective W- and R-rich AMPs by introducing hydrophilic uncharged T residues, which may trigger widespread attention to hydrophilic uncharged amino acid residues, including T residues, and provide new insights into the design of peptide-based antibacterial biomaterials. STATEMENT OF SIGNIFICANCE: We have introduced hydrophilic uncharged T, S, Q or N residues into the minimalist design of W- and R-rich engineered peptides and found that the introduction of these hydrophilic uncharged amino residues, especially the T residues, can significantly improve the cell selectivity of W- and R-rich engineered peptides. The target compound T6 showed potent antibacterial activity, high cell selectivity, strong tolerance, good in vivo efficacy and killed bacteria through multiple mechanisms mainly membrane-disruptive. These findings may spark widespread interest in hydrophilic uncharged amino acid residues, and provide new insights into the design of peptide-based antimicrobial biomaterials.
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Wesseling CJ, Martin NI. Synergy by Perturbing the Gram-Negative Outer Membrane: Opening the Door for Gram-Positive Specific Antibiotics. ACS Infect Dis 2022; 8:1731-1757. [PMID: 35946799 PMCID: PMC9469101 DOI: 10.1021/acsinfecdis.2c00193] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
New approaches to target antibacterial agents toward Gram-negative bacteria are key, given the rise of antibiotic resistance. Since the discovery of polymyxin B nonapeptide as a potent Gram-negative outer membrane (OM)-permeabilizing synergist in the early 1980s, a vast amount of literature on such synergists has been published. This Review addresses a range of peptide-based and small organic compounds that disrupt the OM to elicit a synergistic effect with antibiotics that are otherwise inactive toward Gram-negative bacteria, with synergy defined as a fractional inhibitory concentration index (FICI) of <0.5. Another requirement for the inclusion of the synergists here covered is their potentiation of a specific set of clinically used antibiotics: erythromycin, rifampicin, novobiocin, or vancomycin. In addition, we have focused on those synergists with reported activity against Gram-negative members of the ESKAPE family of pathogens namely, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and/or Acinetobacter baumannii. In cases where the FICI values were not directly reported in the primary literature but could be calculated from the published data, we have done so, allowing for more direct comparison of potency with other synergists. We also address the hemolytic activity of the various OM-disrupting synergists reported in the literature, an effect that is often downplayed but is of key importance in assessing the selectivity of such compounds for Gram-negative bacteria.
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Chai WC, Whittall JJ, Polyak SW, Foo K, Li X, Dutschke CJ, Ogunniyi AD, Ma S, Sykes MJ, Semple SJ, Venter H. Cinnamaldehyde derivatives act as antimicrobial agents against Acinetobacter baumannii through the inhibition of cell division. Front Microbiol 2022; 13:967949. [PMID: 36106080 PMCID: PMC9465178 DOI: 10.3389/fmicb.2022.967949] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 08/05/2022] [Indexed: 11/13/2022] Open
Abstract
Acinetobacter baumannii is a pathogen with high intrinsic antimicrobial resistance while multidrug resistant (MDR) and extensively drug resistant (XDR) strains of this pathogen are emerging. Treatment options for infections by these strains are very limited, hence new therapies are urgently needed. The bacterial cell division protein, FtsZ, is a promising drug target for the development of novel antimicrobial agents. We have previously reported limited activity of cinnamaldehyde analogs against Escherichia coli. In this study, we have determined the antimicrobial activity of six cinnamaldehyde analogs for antimicrobial activity against A. baumannii. Microscopic analysis was performed to determine if the compounds inhibit cell division. The on-target effect of the compounds was assessed by analyzing their effect on polymerization and on the GTPase activity of purified FtsZ from A. baumannii. In silico docking was used to assess the binding of cinnamaldehyde analogs. Finally, in vivo and in vitro safety assays were performed. All six compounds displayed antibacterial activity against the critical priority pathogen A. baumannii, with 4-bromophenyl-substituted 4 displaying the most potent antimicrobial activity (MIC 32 μg/mL). Bioactivity was significantly increased in the presence of an efflux pump inhibitor for A. baumannii ATCC 19606 (up to 32-fold) and significantly, for extensively drug resistant UW 5075 (greater than 4-fold), suggesting that efflux contributes to the intrinsic resistance of A. baumannii against these agents. The compounds inhibited cell division in A. baumannii as observed by the elongated phenotype and targeted the FtsZ protein as seen from the inhibition of polymerization and GTPase activity. In silico docking predicted that the compounds bind in the interdomain cleft adjacent to the H7 core helix. Di-chlorinated 6 was devoid of hemolytic activity and cytotoxicity against mammalian cells in vitro, as well as adverse activity in a Caenorhabditis elegans nematode model in vivo. Together, these findings present halogenated analogs 4 and 6 as promising candidates for further development as antimicrobial agents aimed at combating A. baumannii. This is also the first report of FtsZ-targeting compounds with activity against an XDR A. baumannii strain.
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Affiliation(s)
- Wern Chern Chai
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Jonathan J. Whittall
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Steven W. Polyak
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Klyie Foo
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Xin Li
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Cameron J. Dutschke
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Abiodun D. Ogunniyi
- Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Shutao Ma
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Matthew J. Sykes
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Susan J. Semple
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
- Quality Use of Medicines and Pharmacy Research Centre, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Henrietta Venter
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
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11
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Shirley JD, Nauta KM, Carlson EE. Live-Cell Profiling of Penicillin-Binding Protein Inhibitors in Escherichia coli MG1655. ACS Infect Dis 2022; 8:1241-1252. [PMID: 35763562 PMCID: PMC10040144 DOI: 10.1021/acsinfecdis.2c00004] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Penicillin-binding proteins (PBPs) make up an essential class of bacterial enzymes that carry out the final steps of peptidoglycan synthesis and regulate the recycling of this polymeric structure. PBPs are an excellent drug target and have been the most clinically relevant antibacterial target since the 1940s with the introduction of β-lactams. Despite this, a large gap in knowledge remains regarding the individual function and regulation of each PBP homologue in most bacteria. This can be attributed to a lack of chemical tools and methods that enable the study of individual PBPs in an activity-dependent manner and in their native environment. The development of such methods in Gram-negative bacteria has been particularly challenging due to the presence of an outer membrane and numerous resistance mechanisms. To address this, we have developed an optimized live-cell assay for screening inhibitors of the PBPs in Escherichia coli MG1655. We utilized EDTA to permeabilize Gram-negative cells, enabling increased penetration of our readout probe, Bocillin-FL, and subsequent analysis of PBP-inhibition profiles. To identify scaffolds for future development of PBP-selective activity-based probes, we screened ten β-lactams, one diazabicyclooctane, and one monobactam for their PBP-selectivity profiles in E. coli MG1655. These results demonstrate the utility of our assay for the screening of inhibitors in live, non-hypersusceptible Gram-negative organisms.
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Affiliation(s)
- Joshua D Shirley
- Department of Medicinal Chemistry, University of Minnesota, 208 Harvard Street SE, Minneapolis, Minnesota 55454, United States
| | - Kelsie M Nauta
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Erin E Carlson
- Department of Medicinal Chemistry, University of Minnesota, 208 Harvard Street SE, Minneapolis, Minnesota 55454, United States.,Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States.,Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, 321 Church Street SE, Minneapolis, Minnesota 55454, United States.,Department of Pharmacology, University of Minnesota, 321 Church Street SE, Minneapolis, Minnesota 55454, United States
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12
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Pandur Ž, Dular M, Kostanjšek R, Stopar D. Bacterial cell wall material properties determine E. coli resistance to sonolysis. ULTRASONICS SONOCHEMISTRY 2022; 83:105919. [PMID: 35077964 PMCID: PMC8789596 DOI: 10.1016/j.ultsonch.2022.105919] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/23/2021] [Accepted: 01/13/2022] [Indexed: 05/02/2023]
Abstract
The applications of bacterial sonolysis in industrial settings are plagued by the lack of the knowledge of the exact mechanism of action of sonication on bacterial cells, variable effectiveness of cavitation on bacteria, and inconsistent data of its efficiency. In this study we have systematically changed material properties of E. coli cells to probe the effect of different cell wall layers on bacterial resistance to ultrasonic irradiation (20 kHz, output power 6,73 W, horn type, 3 mm probe tip diameter, 1 ml sample volume). We have determined the rates of sonolysis decay for bacteria with compromised major capsular polymers, disrupted outer membrane, compromised peptidoglycan layer, spheroplasts, giant spheroplasts, and in bacteria with different cell physiology. The non-growing bacteria were 5-fold more resistant to sonolysis than growing bacteria. The most important bacterial cell wall structure that determined the outcome during sonication was peptidoglycan. If peptidoglycan was remodelled, weakened, or absent the cavitation was very efficient. Cells with removed peptidoglycan had sonolysis resistance equal to lipid vesicles and were extremely sensitive to sonolysis. The results suggest that bacterial physiological state as well as cell wall architecture are major determinants that influence the outcome of bacterial sonolysis.
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Affiliation(s)
- Žiga Pandur
- University of Ljubljana, Biotechnical Faculty, Večna pot 111, 1000 Ljubljana, SI-Slovenia; University of Ljubljana, Faculty of Mechanical Engineering, Aškerčeva 6, 1000 Ljubljana, SI-Slovenia
| | - Matevž Dular
- University of Ljubljana, Faculty of Mechanical Engineering, Aškerčeva 6, 1000 Ljubljana, SI-Slovenia
| | - Rok Kostanjšek
- University of Ljubljana, Biotechnical Faculty, Večna pot 111, 1000 Ljubljana, SI-Slovenia
| | - David Stopar
- University of Ljubljana, Biotechnical Faculty, Večna pot 111, 1000 Ljubljana, SI-Slovenia.
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Hamminger C, Glueck M, Fefer M, Ckurshumova W, Liu J, Tenhaken R, Plaetzer K. Photodynamic Inactivation of plant pathogens part II: fungi. Photochem Photobiol Sci 2022; 21:195-207. [PMID: 35044642 DOI: 10.1007/s43630-021-00157-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 12/09/2021] [Indexed: 11/30/2022]
Abstract
The constantly increasing demand for agricultural produce from organic and conventional farming calls for new, sustainable, and biocompatible solutions for crop protection. The overuse of fungicides leading to contamination of both produce and environment and the emergence of plant pathogenic fungi that are resistant to conventional treatments warrant the need for new methods to combat fungal infections in the field. We here deliver the follow-up study to our research on the Photodynamic Inactivation (PDI) of plant pathogenic bacteria (Glueck et al. in Photochem Photobiol Sci 18(7):1700-1708, 2019) by expanding the scope to fungal pathogens. Both fungal species employed in this study-Alternaria solani and Botrytis cinerea-cause substantial crop and economic losses. Sodium magnesium chlorophyllin (Chl, approved as food additive E140) in combination with Na2EDTA and the chlorin e6 derivative B17-0024 holding cationic moieties serve as eco-friendly photoactive compounds. Effectiveness of the antifungal PDI was measured by inhibition of growth of mycelial spheres (average diameter 2-3 mm) after incubation with the photosensitizer for 100 min and subsequent illumination using a LED array (395 nm, 106.6 J cm-2). One hundred micromolar Chl combined with 5 mM Na2EDTA was able to successfully photokill 94.1% of A. solani and 91.7% of B. cinerea samples. PDI based on B17-0024 can completely inactivate A. solani at 10 times lower concentration (10 µM); however, for B. cinerea, the concentration required for complete eradication was similar to that of Chl with Na2EDTA (100 µM). Using a plant compatibility assay based on Fragaria vesca, we further demonstrate that both photosensitizers neither affect host plant development nor cause significant leaf damage. The plants were sprayed with 300 µL of treatment solution used for PDI (one or three treatments on consecutive days) and plant growth was monitored for 21 days. Only minor leaf damage was observed in samples exposed to the chelators Na2EDTA and polyaspartic acid, but overall plant development was unaffected. In conclusion, our results suggest that sodium magnesium chlorophyllin in combination with EDTA and B17-0024 could serve as effective and safe photofungicides.
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Affiliation(s)
- Christoph Hamminger
- Laboratory of Photodynamic Inactivation of Microorganisms, Department of Biosciences and Medical Biology, Paris Lodron University of Salzburg, Hellbrunnerstr. 34, Salzburg, Austria
| | - Michael Glueck
- Laboratory of Photodynamic Inactivation of Microorganisms, Department of Biosciences and Medical Biology, Paris Lodron University of Salzburg, Hellbrunnerstr. 34, Salzburg, Austria
| | - Michael Fefer
- Suncor AgroScience, 2489 North Sheridan Way, Mississauga, ON, L5K1A8, Canada
| | - Wenzi Ckurshumova
- Suncor AgroScience, 2489 North Sheridan Way, Mississauga, ON, L5K1A8, Canada
| | - Jun Liu
- Suncor AgroScience, 2489 North Sheridan Way, Mississauga, ON, L5K1A8, Canada
| | - Raimund Tenhaken
- Plant Physiology, Department of Environment and Biodiversity, University of Salzburg, Hellbrunnerstr. 34, Salzburg, Austria
| | - Kristjan Plaetzer
- Laboratory of Photodynamic Inactivation of Microorganisms, Department of Biosciences and Medical Biology, Paris Lodron University of Salzburg, Hellbrunnerstr. 34, Salzburg, Austria.
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14
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Potent antibacterial and antibiofilm activities of TICbf-14, a peptide with increased stability against trypsin. J Microbiol 2021; 60:89-99. [PMID: 34964945 DOI: 10.1007/s12275-022-1368-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 09/17/2021] [Accepted: 10/01/2021] [Indexed: 10/19/2022]
Abstract
The poor stability of peptides against trypsin largely limits their development as potential antibacterial agents. Here, to obtain a peptide with increased trypsin stability and potent antibacterial activity, TICbf-14 derived from the cationic peptide Cbf-14 was designed by the addition of disulfide-bridged hendecapeptide (CWTKSIPPKPC) loop. Subsequently, the trypsin stability and antimicrobial and antibiofilm activities of this peptide were evaluated. The possible mechanisms underlying its mode of action were also clarified. The results showed that TICbf-14 exhibited elevated trypsin inhibitory activity and effectively mitigated lung histopathological damage in bacteria-infected mice by reducing the bacterial counts, further inhibiting the systemic dissemination of bacteria and host inflammation. Additionally, TICbf-14 significantly repressed bacterial swimming motility and notably inhibited biofilm formation. Considering the mode of action, we observed that TICbf-14 exhibited a potent membrane-disruptive mechanism, which was attributable to its destructive effect on ionic bridges between divalent cations and LPS of the bacterial membrane. Overall, TICbf-14, a bifunctional peptide with both antimicrobial and trypsin inhibitory activity, is highly likely to become an ideal candidate for drug development against bacteria.
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15
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Insights into the antibacterial mechanism of action of chelating agents by selective deprivation of iron, manganese and zinc. Appl Environ Microbiol 2021; 88:e0164121. [PMID: 34788072 PMCID: PMC8788741 DOI: 10.1128/aem.01641-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial growth and proliferation can be restricted by limiting the availability of metal ions in their environment. Humans sequester iron, manganese, and zinc to help prevent infection by pathogens, a system termed nutritional immunity. Commercially used chelants have high binding affinities with a variety of metal ions, which may lead to antibacterial properties that mimic these innate immune processes. However, the modes of action of many of these chelating agents in bacterial growth inhibition and their selectivity in metal deprivation in cellulo remain ill-defined. We address this shortcoming by examining the effect of 11 chelators on Escherichia coli growth and their impact on the cellular concentration of five metals. The following four distinct effects were uncovered: (i) no apparent alteration in metal composition, (ii) depletion of manganese alongside reductions in iron and zinc levels, (iii) reduced zinc levels with a modest reduction in manganese, and (iv) reduced iron levels coupled with elevated manganese. These effects do not correlate with the absolute known chelant metal ion affinities in solution; however, for at least five chelators for which key data are available, they can be explained by differences in the relative affinity of chelants for each metal ion. The results reveal significant insights into the mechanism of growth inhibition by chelants, highlighting their potential as antibacterials and as tools to probe how bacteria tolerate selective metal deprivation. IMPORTANCE Chelating agents are widely used in industry and consumer goods to control metal availability, with bacterial growth restriction as a secondary benefit for preservation. However, the antibacterial mechanism of action of chelants is largely unknown, particularly with respect to the impact on cellular metal concentrations. The work presented here uncovers distinct metal starvation effects imposed by different chelants on the model Gram-negative bacterium Escherichia coli. The chelators were studied both individually and in pairs, with the majority producing synergistic effects in combinations that maximize antibacterial hostility. The judicious selection of chelants based on contrasting cellular effects should enable reductions in the quantities of chelant required in numerous commercial products and presents opportunities to replace problematic chemistries with biodegradable alternatives.
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Immobilization of Polyethyleneimine (PEI) on Flat Surfaces and Nanoparticles Affects Its Ability to Disrupt Bacterial Membranes. Microorganisms 2021; 9:microorganisms9102176. [PMID: 34683497 PMCID: PMC8540495 DOI: 10.3390/microorganisms9102176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/11/2021] [Accepted: 10/15/2021] [Indexed: 11/17/2022] Open
Abstract
Interactions between a widely used polycationic polymer, polyethyleneimine (PEI), and a Gram-negative bacteria, E. coli, are investigated using atomic force microscopy (AFM) quantitative imaging. The effect of PEI, a known membrane permeabilizer, is characterized by probing both the structure and elasticity of the bacterial cell envelope. At low concentrations, PEI induced nanoscale membrane perturbations all over the bacterial surface. Despite these structural changes, no change in cellular mechanics (Young’s modulus) was detected and the growth of E. coli is barely affected. However, at high PEI concentrations, dramatic changes in both structure and cell mechanics are observed. When immobilized on a flat surface, the ability of PEI to alter the membrane structure and reduce bacterial elasticity is diminished. We further probe this immobilization-induced effect by covalently attaching the polymer to the surface of polydopamine nanoparticles (PDNP). The nanoparticle-immobilized PEI (PDNP-PEI), though not able to induce major structural changes on the outer membrane of E. coli (in contrast to the flat surface), was able to bind to and reduce the Young’s modulus of the bacteria. Taken together, our data demonstrate that the state of polycationic polymers, whether bound or free—which greatly dictates their overall configuration—plays a major role on how they interact with and disrupt bacterial membranes.
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17
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Wu Z, Zhang Y, Xu X, Ahmed T, Yang Y, Loh B, Leptihn S, Yan C, Chen J, Li B. The Holin-Endolysin Lysis System of the OP2-Like Phage X2 Infecting Xanthomonas oryzae pv. oryzae. Viruses 2021; 13:v13101949. [PMID: 34696380 PMCID: PMC8541568 DOI: 10.3390/v13101949] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 09/18/2021] [Accepted: 09/21/2021] [Indexed: 01/01/2023] Open
Abstract
Most endolysins of dsDNA phages are exported by a holin-dependent mechanism, while in some cases endolysins are exported via a holin-independent mechanism. However, it is still unclear whether the same endolysins can be exported by both holin-dependent and holin-independent mechanisms. This study investigated the lysis system of OP2-like phage X2 infecting Xanthomonas oryzae pv. oryzae, causing devastating bacterial leaf blight disease in rice. Based on bioinformatics and protein biochemistry methods, we show that phage X2 employs the classic "holin-endolysin" lysis system. The endolysin acts on the cell envelope and exhibits antibacterial effects in vitro, while the holin facilitates the release of the protein into the periplasm. We also characterized the role of the transmembrane domain (TMD) in the translocation of the endolysin across the inner membrane. We found that the TMD facilitated the translocation of the endolysin via the Sec secretion system. The holin increases the efficiency of protein release, leading to faster and more efficient lysis. Interestingly, in E. coli, the expression of either holin or endolysin with TMDs resulted in the formation of long rod shaped cells. We conclude that the TMD of X2-Lys plays a dual role: One is the transmembrane transport while the other is the inhibition of cell division, resulting in larger cells and thus in a higher number of released viruses per cell.
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Affiliation(s)
- Zhifeng Wu
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (Z.W.); (Y.Z.); (X.X.); (T.A.)
| | - Yang Zhang
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (Z.W.); (Y.Z.); (X.X.); (T.A.)
| | - Xinyang Xu
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (Z.W.); (Y.Z.); (X.X.); (T.A.)
| | - Temoor Ahmed
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (Z.W.); (Y.Z.); (X.X.); (T.A.)
| | - Yong Yang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (Y.Y.); (C.Y.)
| | - Belinda Loh
- University of Edinburgh Institute, Zhejiang University, Hangzhou 314400, China; (B.L.); (S.L.)
| | - Sebastian Leptihn
- University of Edinburgh Institute, Zhejiang University, Hangzhou 314400, China; (B.L.); (S.L.)
| | - Chenqi Yan
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (Y.Y.); (C.Y.)
- Institute of Plant Virology, Ningbo University, Ningbo 315211, China
| | - Jianping Chen
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (Y.Y.); (C.Y.)
- Institute of Plant Virology, Ningbo University, Ningbo 315211, China
- Correspondence: (J.C.); (B.L.); Tel.: +86-571-8898-2412 (B.L.)
| | - Bin Li
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (Z.W.); (Y.Z.); (X.X.); (T.A.)
- Correspondence: (J.C.); (B.L.); Tel.: +86-571-8898-2412 (B.L.)
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18
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Melo-López FN, Zermeño-Cervantes LA, Barraza A, Loera-Muro A, Cardona-Félix CS. Biochemical characterization of LysVpKK5 endolysin from a marine vibriophage. Protein Expr Purif 2021; 188:105971. [PMID: 34508857 DOI: 10.1016/j.pep.2021.105971] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 09/04/2021] [Accepted: 09/06/2021] [Indexed: 10/20/2022]
Abstract
Endolysins have been proposed as a potential antibacterial alternative for aquaculture, especially against Vibrio; the bacterial-agents that most frequently cause disease. Although multiple marine vibriophages have been characterized to date, research on vibriophage endolysins is recent. In this study, biochemical characterization of LysVpKK5 endolysin encoded by Vibrio parahaemolyticus-infecting VpKK5 phage was performed. In silico analysis revealed that LysVpKK5 possesses a conserved amidase_2 domain with a zinc-binding motif of high structural similarity to T7 lysozyme (RMSD = 0.107 Å). Contrary to expectations, the activity was inhibited with Zn2+ and was improved with other divalent cations, especially Ca2+. It showed optimal muralytic activity at pH 10, and curiously, no lytic activity at pH ≤ 7 was recorded. As for the thermal stability test, the optimal activity was recorded at 30 °C; the higher residual activity was recorded at 4 °C, and was lost at ≥ 50 °C. On the other hand, increasing NaCl concentrations reduced the activity gradually; the optimal activity was recorded at 50 mM NaCl. On the other hand, the enzymatic activity at 0.5 M NaCl was approx 30% and of approx 50% in seawater. LysVpKK5 endolysin exhibited a higher activity on V. parahaemolyticus ATCC-17802 strain, in comparison with AHPND + strains.
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Affiliation(s)
| | | | - Aarón Barraza
- CONACYT-Centro de Investigaciones Biológicas del Noroeste, SC. Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz, B.C.S, 23096, Mexico
| | - Abraham Loera-Muro
- CONACYT-Centro de Investigaciones Biológicas del Noroeste, SC. Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz, B.C.S, 23096, Mexico
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19
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Naaz F, Agrawal M, Chakraborty S, Tirumkudulu MS, Venkatesh KV. Ligand sensing enhances bacterial flagellar motor output via stator recruitment. eLife 2021; 10:62848. [PMID: 33821791 PMCID: PMC8062133 DOI: 10.7554/elife.62848] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 04/03/2021] [Indexed: 11/13/2022] Open
Abstract
It is well known that flagellated bacteria, such as Escherichia coli, sense chemicals in their environment by a chemoreceptor and relay the signals via a well-characterized signaling pathway to the flagellar motor. It is widely accepted that the signals change the rotation bias of the motor without influencing the motor speed. Here, we present results to the contrary and show that the bacteria is also capable of modulating motor speed on merely sensing a ligand. Step changes in concentration of non-metabolizable ligand cause temporary recruitment of stator units leading to a momentary increase in motor speeds. For metabolizable ligand, the combined effect of sensing and metabolism leads to higher motor speeds for longer durations. Experiments performed with mutant strains delineate the role of metabolism and sensing in the modulation of motor speed and show how speed changes along with changes in bias can significantly enhance response to changes in its environment.
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Affiliation(s)
- Farha Naaz
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Megha Agrawal
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Soumyadeep Chakraborty
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Mahesh S Tirumkudulu
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - K V Venkatesh
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
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20
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Di Martino P. Ways to improve biocides for metalworking fluid. AIMS Microbiol 2021; 7:13-27. [PMID: 33659766 PMCID: PMC7921375 DOI: 10.3934/microbiol.2021002] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 01/13/2021] [Indexed: 11/25/2022] Open
Abstract
Metalworking fluids (MWF) are mainly emulsions of oil in water containing additives such as corrosion inhibitors, emulsifiers, defoamers, and biocides. Microbial contamination of MWF is almost systematic, and some of their constituents serve as nutrients for contaminating microorganisms. Biocides for MWF are protection products used to counter microbial contaminations and growth. Ideally, a biocide for MWF should have the following non-exhaustive criteria: have a broad-spectrum activity, be usable at low concentrations, be compatible with the formulation and the physical-chemical properties of MWF, be stable over time, retain its effectiveness in the presence of soiling, have no corrosive action on metals, present no danger to humans and the environment, be inexpensive. The future lies in the development of new molecules with biocidal activity corresponding to these ideal specifications, but in the meantime, it is possible to improve the performance of existing molecules currently on the market. Different strategies for potentiation of the activity of existing biocides are possible. The compatibility of the potentiation strategies with their use in metal working fluids is discussed.
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Affiliation(s)
- Patrick Di Martino
- Laboratoire ERRMECe, Cergy-Paris Université, 1 rue Descartes 95000 Neuville-sur-Oise, France
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21
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Okamoto K, Kanayama S, Ikeda F, Fujikawa K, Fujiwara S, Nozawa N, Mori S, Matsumoto T, Hayashi N, Oda M. Broad spectrum in vitro microbicidal activity of benzoyl peroxide against microorganisms related to cutaneous diseases. J Dermatol 2020; 48:551-555. [PMID: 33369759 PMCID: PMC8048985 DOI: 10.1111/1346-8138.15739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 11/24/2020] [Accepted: 12/04/2020] [Indexed: 11/27/2022]
Abstract
The in vitro microbicidal activity of benzoyl peroxide against Cutibacterium acnes, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Malassezia furfur, Malassezia restricta, and Malassezia globosa was investigated. These strains were incubated for 1 h in the presence of 0.25, 0.5, 1, or 2 mmol/L benzoyl peroxide in phosphate buffered saline supplemented with 0.1% glycerol and 2% Tween 80. After exposure to benzoyl peroxide, counts of viable Gram-positive bacteria and fungi were markedly decreased, whereas counts of Gram-negative bacteria were unchanged. Transmission electron microscopy images showed a decrease in electron density and the destruction of C. acnes and M. restricta cell walls after exposure to 2 mmol/L benzoyl peroxide. In conclusion, this study showed that benzoyl peroxide has a potent and rapid microbicidal activity against Gram-positive bacteria and fungi that are associated with various cutaneous diseases. This suggests that the direct destruction of bacterial cell walls by benzoyl peroxide is an essential mechanism of its rapid and potent microbicidal activity against microorganisms.
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Affiliation(s)
- Kazuaki Okamoto
- Information Systems Department, Maruho Co., Ltd., Osaka, Japan.,Department of Microbiology and Infection Control Science, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Shoji Kanayama
- Department of Microbiology and Infection Control Science, Kyoto Pharmaceutical University, Kyoto, Japan.,Drug Development Research Laboratories, Kyoto R&D Center, Maruho Co., Ltd., Kyoto, Japan
| | - Fumiaki Ikeda
- Drug Discovery Research Department, Kyoto R&D Center, Maruho Co., Ltd., Kyoto, Japan
| | - Koki Fujikawa
- Drug Development Research Laboratories, Kyoto R&D Center, Maruho Co., Ltd., Kyoto, Japan
| | - Shiori Fujiwara
- Drug Discovery Research Department, Kyoto R&D Center, Maruho Co., Ltd., Kyoto, Japan
| | - Naoki Nozawa
- Drug Discovery Research Department, Kyoto R&D Center, Maruho Co., Ltd., Kyoto, Japan
| | - Sachi Mori
- Drug Development Research Laboratories, Kyoto R&D Center, Maruho Co., Ltd., Kyoto, Japan
| | - Tatsumi Matsumoto
- Drug Discovery Research Department, Kyoto R&D Center, Maruho Co., Ltd., Kyoto, Japan
| | - Naoki Hayashi
- Department of Microbiology and Infection Control Science, Kyoto Pharmaceutical University, Kyoto, Japan.,Drug Development Research Laboratories, Kyoto R&D Center, Maruho Co., Ltd., Kyoto, Japan
| | - Masataka Oda
- Department of Microbiology and Infection Control Science, Kyoto Pharmaceutical University, Kyoto, Japan
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22
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Zhang L, Zhao SQ, Zhang J, Sun Y, Xie YL, Liu YB, Ma CC, Jiang BG, Liao XY, Li WF, Cheng XJ, Wang ZL. Proteomic Analysis of Vesicle-Producing Pseudomonas aeruginosa PAO1 Exposed to X-Ray Irradiation. Front Microbiol 2020; 11:558233. [PMID: 33384665 PMCID: PMC7770229 DOI: 10.3389/fmicb.2020.558233] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 11/25/2020] [Indexed: 02/05/2023] Open
Abstract
Ionizing irradiation kills pathogens by destroying nucleic acids without protein structure destruction. However, how pathogens respond to irradiation stress has not yet been fully elucidated. Here, we observed that Pseudomonas aeruginosa PAO1 could release nucleic acids into the extracellular environment under X-ray irradiation. Using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), X-ray irradiation was observed to induce outer membrane vesicle (OMV) formation in P. aeruginosa PAO1. The size distribution of the OMVs of the irradiated PAO1 was similar to that of the OMVs of the non-irradiated PAO1 according to nanoparticle tracking analysis (NTA). The pyocin-related proteins are involved in OMV production in P. aeruginosa PAO1 under X-ray irradiation conditions, and that this is regulated by the key SOS gene recA. The OMV production was significantly impaired in the irradiated PAO1 Δlys mutant, suggesting that Lys endolysin is associated with OMV production in P. aeruginosa PAO1 upon irradiation stress. Meanwhile, no significant difference in OMV production was observed between PAO1 lacking the pqsR, lasR, or rhlR genes and the parent strain, demonstrating that the irradiation-induced OMV biosynthesis of P. aeruginosa was independent of the Pseudomonas quinolone signal (PQS).
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Affiliation(s)
- Li Zhang
- State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Shi-Qiao Zhao
- Department of Clinical Laboratory, Chongqing Traditional Chinese Medicine Hospital, Chongqing, China
| | - Jie Zhang
- Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Ying Sun
- State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Ya-Liu Xie
- Department of Otolaryngology, The Seventh People's Hospital of Chengdu, Chengdu, China
| | - Yan-Bin Liu
- Infectious Diseases Center, West China Hospital, Sichuan University, Chengdu, China
| | - Cui-Cui Ma
- State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Bo-Guang Jiang
- State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Xue-Yuan Liao
- State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Wen-Fang Li
- State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Xing-Jun Cheng
- State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Zhen-Ling Wang
- State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
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Lombardo M, Espósito BP, Lourenço FR, Kaneko TM. The application of pharmaceutical quality by design concepts to evaluate the antioxidant and antimicrobial properties of a preservative system including desferrioxamine. Daru 2020; 28:635-646. [PMID: 32856238 PMCID: PMC7704847 DOI: 10.1007/s40199-020-00370-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 08/21/2020] [Indexed: 10/23/2022] Open
Abstract
BACKGROUND The purpose of the present study was to investigate the antioxidant and antimicrobial activities of a conventional preservative system containing desferrioxamine mesylate (DFO) and optimize the composition of the system through mathematical models. METHODS Different combinations of ethylenediaminetetraacetic acid (EDTA), sodium metabisulfite (SM), DFO and methylparaben (MP) were prepared using factorial design of experiments. The systems were added to ascorbic acid (AA) solution and the AA content over time, at room temperature and at 40 °C was determined by volumetric assay. The systems were also evaluated for antioxidant activity by a fluorescence-based assay. Antimicrobial activity was assessed by microdilution technique and photometric detection against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Aspergillus brasiliensis. A multi-criteria decision approach was adopted to optimize all responses by desirability functions. RESULTS DFO did not extend the stability of AA over time, but displayed a better ability than EDTA to block the pro-oxidant activity of iron. DFO had a positive interaction with MP in microbial growth inhibition. The mathematical models showed adequate capacity to predict the responses. Statistical optimization aiming to meet the quality specifications of the ascorbic acid solution indicated that the presence of DFO in the composition allows to decrease the concentrations of EDTA, SM and MP. CONCLUSION DFO was much more effective than EDTA in preventing iron-catalyzed oxidation. In addition, DFO improved the inhibitory response of most microorganisms tested. The Quality by Design concepts aided in predicting an optimized preservative system with reduced levels of conventional antioxidants and preservatives, suggesting DFO as a candidate for multifunctional excipient.
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Affiliation(s)
- Márcia Lombardo
- Department of Pharmacy, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
- Center of Drugs, Cosmetics and Sanitizing Products, Adolfo Lutz Institute, São Paulo, Brazil.
| | - Breno Pannia Espósito
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Felipe Rebello Lourenço
- Department of Pharmacy, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Telma Mary Kaneko
- Department of Pharmacy, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
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24
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Piñar G, Sclocchi MC, Pinzari F, Colaizzi P, Graf A, Sebastiani ML, Sterflinger K. The Microbiome of Leonardo da Vinci's Drawings: A Bio-Archive of Their History. Front Microbiol 2020; 11:593401. [PMID: 33329475 PMCID: PMC7718017 DOI: 10.3389/fmicb.2020.593401] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/26/2020] [Indexed: 12/04/2022] Open
Abstract
Seven emblematic Leonardo da Vinci’s drawings were investigated through third generation sequencing technology (Nanopore). In addition, SEM analyses were carried out to acquire photographic documentation and to infer the nature of the micro-objects removed from the surface of the drawings. The Nanopore generated microbiomes can be used as a “bio-archive” of the drawings, offering a kind of fingerprint for current and future biological comparisons. This information might help to create a biological catalog of the drawings (cataloging), a microbiome-fingerprint for each single analyzed drawing, as a reference dataset for future studies (monitoring) and last but not least a bio-archive of the history of each single object (added value). Results showed a relatively high contamination with human DNA and a surprising dominance of bacteria over fungi. However, it was possible to identify typical bacteria of the human microbiome, which are mere contaminants introduced by handling of the drawings as well as other microorganisms that seem to have been introduced through vectors, such as insects and their droppings, visible through the SEM analyses. All drawings showed very specific bio-archives, but a core microbiome of bacteria and fungi that are repeatedly found in this type of material as true degraders were identified, such as members of the phyla Proteobacteria, Actinobacteria, and Firmicutes among bacteria, and fungi belonging to the classes Sordariomycetes and Eurotiomycetes. In addition, some similarities were observed that could be influenced by their geographical location (Rome or Turin), indicating the influence of this factor and denoting the importance of environmental and storage conditions on the specific microbiomes.
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Affiliation(s)
- Guadalupe Piñar
- Department of Biotechnology, Institute of Microbiology and Microbial Biotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
| | - Maria Carla Sclocchi
- Laboratorio di Biologia, Istituto Centrale per la Patologia degli Archivi e del Libro (ICPAL), Rome, Italy
| | - Flavia Pinzari
- Institute for Biological Systems (ISB), Council of National Research of Italy (CNR), Monterotondo, Italy
| | - Piero Colaizzi
- Laboratorio di Biologia, Istituto Centrale per la Patologia degli Archivi e del Libro (ICPAL), Rome, Italy
| | - Alexandra Graf
- Applied Life Sciences/Bioengineering/Bioinformatics, FH Campus, Vienna, Austria
| | - Maria Letizia Sebastiani
- Laboratorio di Biologia, Istituto Centrale per la Patologia degli Archivi e del Libro (ICPAL), Rome, Italy
| | - Katja Sterflinger
- Department of Biotechnology, Institute of Microbiology and Microbial Biotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
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Hyun S, Choi Y, Jo D, Choo S, Park TW, Park SJ, Kim S, Lee S, Park S, Jin SM, Cheon DH, Yoo W, Arya R, Chong YP, Kim KK, Kim YS, Lee Y, Yu J. Proline Hinged Amphipathic α-Helical Peptide Sensitizes Gram-Negative Bacteria to Various Gram-Positive Antibiotics. J Med Chem 2020; 63:14937-14950. [DOI: 10.1021/acs.jmedchem.0c01506] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Soonsil Hyun
- Department of Chemistry & Education, Seoul National University, Seoul 08826, Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, Korea
| | - Yoonhwa Choi
- Department of Chemistry & Education, Seoul National University, Seoul 08826, Korea
| | - Doyeon Jo
- Department of Chemistry & Education, Seoul National University, Seoul 08826, Korea
| | - Seolah Choo
- Department of Chemistry & Education, Seoul National University, Seoul 08826, Korea
| | - Tae Woo Park
- Department of Chemistry & Education, Seoul National University, Seoul 08826, Korea
| | - Su-Jin Park
- Department of Infectious Disease, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Seoyeon Kim
- Department of Chemistry & Education, Seoul National University, Seoul 08826, Korea
| | - Seonju Lee
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | - Sohyun Park
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | - Sun Mi Jin
- Department of Chemistry & Education, Seoul National University, Seoul 08826, Korea
| | - Dae Hee Cheon
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | - Wanki Yoo
- Department of Precision Medicine, Sungkyunkwan University School of Medicine, Suwon 16419, Korea
| | - Rekha Arya
- Department of Precision Medicine, Sungkyunkwan University School of Medicine, Suwon 16419, Korea
| | - Yong Pil Chong
- Department of Infectious Disease, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Kyeong Kyu Kim
- Department of Precision Medicine, Sungkyunkwan University School of Medicine, Suwon 16419, Korea
| | - Yang Soo Kim
- Department of Infectious Disease, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Yan Lee
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | - Jaehoon Yu
- Department of Chemistry & Education, Seoul National University, Seoul 08826, Korea
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26
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Antibacterial Effects of Bicarbonate in Media Modified to Mimic Cystic Fibrosis Sputum. Int J Mol Sci 2020; 21:ijms21228614. [PMID: 33207565 PMCID: PMC7696793 DOI: 10.3390/ijms21228614] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/06/2020] [Accepted: 11/14/2020] [Indexed: 12/18/2022] Open
Abstract
Cystic fibrosis (CF) is a hereditary disease caused by mutations in the gene encoding an epithelial anion channel. In CF, Cl− and HCO3− hyposecretion, together with mucin hypersecretion, leads to airway dehydration and production of viscous mucus. This habitat is ideal for colonization by pathogenic bacteria. We have recently demonstrated that HCO3− inhibits the growth and biofilm formation of Pseudomonas aeruginosa and Staphylococcus aureus when tested in laboratory culture media. Using the same bacteria our aim was to investigate the effects of HCO3− in artificial sputum medium (ASM), whose composition resembles CF mucus. Control ASM containing no NaHCO3 was incubated in ambient air (pH 7.4 or 8.0). ASM containing NaHCO3 (25 and 100 mM) was incubated in 5% CO2 (pH 7.4 and 8.0, respectively). Viable P. aeruginosa and S. aureus cells were counted by colony-forming unit assay and flow cytometry after 6 h and 17 h of incubation. Biofilm formation was assessed after 48 h. The data show that HCO3− significantly decreased viable cell counts and biofilm formation in a concentration-dependent manner. These effects were due neither to extracellular alkalinization nor to altered osmolarity. These results show that HCO3− exerts direct antibacterial and antibiofilm effects on prevalent CF bacteria.
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27
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Rhodopseudomonas palustris CGA009 polyhydroxybutyrate production from a lignin aromatic and quantification via flow cytometry. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/j.biteb.2020.100474] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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28
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Hassett DJ, Meyer TJ. A Novel Bactericidal Drug Effective Against Gram-Positive and Gram-Negative Pathogenic Bacteria: Easy as AB569. DNA Cell Biol 2020; 39:1473-1477. [PMID: 32721230 DOI: 10.1089/dna.2020.5824] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Global antibiotic resistance, driven by intensive antibiotic exposure/abuse, constitutes a serious challenge to all health care, particularly in an era when new antimicrobial development has slowed to a trickle. Recently, we published work demonstrating the discovery and partial mechanism of action of a novel bactericidal agent that is effective against both gram-positive and gram-negative multidrug-resistant bacteria. This drug, called AB569, consists of acidified nitrite (A-NO2-) and EDTA, of which there is no mechanism of resistance. Using both chemistry-, genetic-, and bioinformatics-based techniques, we first discovered that AB569 was able to generate bactericidal levels of nitric oxide (NO), while the EDTA component stabilized S-nitrosyl thiols, thereby furthering NO and downstream reactive nitrogen species production. This elegant chemistry triggered a paralytic downregulation of vital genes using RNA-seq involved in the synthesis of DNA, RNA, ATP, and protein in the representative ESKAPE pathogen, Pseudomonas aeruginosa.
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Affiliation(s)
- Daniel J Hassett
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Thomas J Meyer
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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29
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Laws M, Shaaban A, Rahman KM. Antibiotic resistance breakers: current approaches and future directions. FEMS Microbiol Rev 2020; 43:490-516. [PMID: 31150547 PMCID: PMC6736374 DOI: 10.1093/femsre/fuz014] [Citation(s) in RCA: 149] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 05/30/2019] [Indexed: 12/15/2022] Open
Abstract
Infections of antibiotic-resistant pathogens pose an ever-increasing threat to mankind. The investigation of novel approaches for tackling the antimicrobial resistance crisis must be part of any global response to this problem if an untimely reversion to the pre-penicillin era of medicine is to be avoided. One such promising avenue of research involves so-called antibiotic resistance breakers (ARBs), capable of re-sensitising resistant bacteria to antibiotics. Although some ARBs have previously been employed in the clinical setting, such as the β-lactam inhibitors, we posit that the broader field of ARB research can yet yield a greater diversity of more effective therapeutic agents than have been previously achieved. This review introduces the area of ARB research, summarises the current state of ARB development with emphasis on the various major classes of ARBs currently being investigated and their modes of action, and offers a perspective on the future direction of the field.
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Affiliation(s)
- Mark Laws
- Institute of Pharmaceutical Sciences, School of Cancer and Pharmaceutical Sciences, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NH
| | - Ali Shaaban
- Institute of Pharmaceutical Sciences, School of Cancer and Pharmaceutical Sciences, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NH
| | - Khondaker Miraz Rahman
- Institute of Pharmaceutical Sciences, School of Cancer and Pharmaceutical Sciences, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NH
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30
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Ullmann IF, Nygaard AB, Tunsjø HS, Charnock C. Whole genome sequencing and antibiotic diffusion assays, provide new insight on drug resistance in the genus Pedobacter. FEMS Microbiol Ecol 2020; 96:5835219. [PMID: 32386210 PMCID: PMC7254926 DOI: 10.1093/femsec/fiaa088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 05/08/2020] [Indexed: 12/29/2022] Open
Abstract
A total of four strains of the ‘environmental superbug’ Pedobacter isolated from sludge produced at Norwegian drinking water treatment plants, were characterized by whole genome sequencing and antibiotic susceptibility assays. As with previous studies on members of this genus, we found that the isolates were multi-drug resistant, and that this resistance included clinically important beta-lactams, aminoglycosides and the fluoroquinolone ciprofloxacin. Using the minION sequencing platform (Oxford Nanopore Technologies) combined with HiSeq PE150 Illumina sequencing data, the four isolates were assembled into genomes of single contigs. Analysis of the genomes revealed potential genetic factors possibly underlying some of the specific resistances observed. Metallo-beta-lactamase activity was detected in one isolate, and the same isolate contained a putative metallo-betalactamase gene resembling pedo-2. Furthermore, several genes related to multidrug efflux systems were found using the resistance database CARD. Additionally, the present study extends our knowledge on the phylogeny of this genus, adding four new genomes to the existing 50.
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Affiliation(s)
- Ingvild Falkum Ullmann
- Oslo Metropolitan University, Faculty of Health Sciences, Department of Life Sciences and Health, NO-0130, Oslo, Norway
| | - Anders Benteson Nygaard
- Oslo Metropolitan University, Faculty of Health Sciences, Department of Life Sciences and Health, NO-0130, Oslo, Norway
| | - Hege Smith Tunsjø
- Oslo Metropolitan University, Faculty of Health Sciences, Department of Life Sciences and Health, NO-0130, Oslo, Norway.,Department of Microbiology and Infection control, Akershus University Hospital, Lørenskog, Norway
| | - Colin Charnock
- Oslo Metropolitan University, Faculty of Health Sciences, Department of Life Sciences and Health, NO-0130, Oslo, Norway
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31
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Blood Compatibility-An Important but Often Forgotten Aspect of the Characterization of Antimicrobial Peptides for Clinical Application. Int J Mol Sci 2019; 20:ijms20215426. [PMID: 31683553 PMCID: PMC6862080 DOI: 10.3390/ijms20215426] [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: 09/18/2019] [Revised: 10/28/2019] [Accepted: 10/30/2019] [Indexed: 12/15/2022] Open
Abstract
Acylation of antimicrobial peptides mimics the structure of the natural lipopeptide polymyxin B, and increases antimicrobial and endotoxin-neutralizing activities. In this study, the antimicrobial properties of lactoferrin-based LF11 peptides as well as blood compatibility as a function of acyl chain length were investigated. Beyond the classical hemolysis test, the biocompatibility was determined with human leukocytes and platelets, and the influence of antimicrobial peptides (AMPs) on the plasmatic coagulation and the complement system was investigated. The results of this study show that the acylation of cationic peptides significantly reduces blood tolerance. With increasing acyl chain length, the cytotoxicity of LF11 peptides to human blood cells also increased. This study also shows that acylated cationic antimicrobial peptides are inactivated by the presence of heparin. In addition, it could be shown that the immobilization of LF11 peptides leads to a loss of their antimicrobial properties.
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32
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Dong JJ, Muszanska A, Xiang F, Falkenberg R, van de Belt-Gritter B, Loontjens T. Contact Killing of Gram-Positive and Gram-Negative Bacteria on PDMS Provided with Immobilized Hyperbranched Antibacterial Coatings. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:14108-14116. [PMID: 31568724 PMCID: PMC6822135 DOI: 10.1021/acs.langmuir.9b02549] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/20/2019] [Indexed: 05/19/2023]
Abstract
Here we describe in detail the preparation and application of antibacterial coatings on PDMS (poly(dimethylsiloxane)) and the contact-killing properties with 10 bacterial strains. Our aim was to develop a generally applicable coating to prevent biomaterial acquired infections, which is the major mode of failure of biomedical implants. In the first step, the surface was provided with a hydrophobic hyperbranched coating resin that was covalently attached to PDMS, mediated by an appropriate coupling agent. The coupling agent contained a siloxane group that reacts covalently with the silanol groups of air-plasma-treated PDMS and a blocked isocyanate enabling covalent coupling with the amino groups of the hyperbranched coating resins. The coating resins were functionalized with a polyethylenimine and subsequently quaternized with bromohexane and iodomethane. The coatings were highly effective against Gram-positive bacteria (five strains) and sufficiently active against Gram-negative bacteria (five stains). The killing effect on the latter group was strongly enhanced by adding a permeabilizer (EDTA). The biocidal efficacy was not influenced by the presence of (saliva) proteins.
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Affiliation(s)
- Jia Jia Dong
- Department
of Polymer Chemistry, Zernike Institute
for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Agnieszka Muszanska
- Department
of Biomedical Engineering, University of
Groningen and University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Fei Xiang
- Department
of Polymer Chemistry, Zernike Institute
for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | | | - Betsy van de Belt-Gritter
- Department
of Biomedical Engineering, University of
Groningen and University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Ton Loontjens
- Department
of Polymer Chemistry, Zernike Institute
for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
- E-mail:
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Côté H, Pichette A, Simard F, Ouellette ME, Ripoll L, Mihoub M, Grimard D, Legault J. Balsacone C, a New Antibiotic Targeting Bacterial Cell Membranes, Inhibits Clinical Isolates of Methicillin-Resistant Staphylococcus aureus (MRSA) Without Inducing Resistance. Front Microbiol 2019; 10:2341. [PMID: 31681206 PMCID: PMC6804428 DOI: 10.3389/fmicb.2019.02341] [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: 03/19/2019] [Accepted: 09/25/2019] [Indexed: 12/20/2022] Open
Abstract
New options are urgently needed for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. Balsacone C is a new dihydrochalcone extracted from Populus balsamifera that has been reported previously as being active against Staphylococcus aureus. Here, we evaluate the antibacterial activity of balsacone C against MRSA. Thirty-four (34) MRSA isolates were obtained from hospitalized patients; these isolates were then characterized for their resistance. Most of these MRSA (>85%) were resistant to penicillin, amoxicillin/clavulanic acid, ciprofloxacin, moxifloxacin, levofloxacin, clindamycin, erythromycin, and cefoxitin as well as being sensitive to linezolid, trimethoprim/sulfamethoxazole, rifampicin, and gentamicin. When tested against all MRSA isolates and various gram-positive bacteria, the antibacterial activity of balsacone C produced a MIC of 3-11.6 mg/mL. We observed no resistant isolates of MRSA (against balsacone C) even after 30 passages. Microscopy fluorescence showed that bacteria cell membrane integrity was compromised by low concentrations of balsacone C. Scanning electron microscope (SEM) confirmed balsacone C-provoked changes in the bacterial cell membrane and we find a dose-dependent release of DNA and proteins. This loss of cellular integrity leads to cell death and suggests a low potential for the development of spontaneous resistance.
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Affiliation(s)
- Héloïse Côté
- Laboratoire d’Analyse et de Séparation des Essences Végétales, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
| | - André Pichette
- Laboratoire d’Analyse et de Séparation des Essences Végétales, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
- Centre de Recherche sur la Boréalie, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
| | - François Simard
- Laboratoire d’Analyse et de Séparation des Essences Végétales, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
| | - Marie-Eve Ouellette
- Laboratoire d’Analyse et de Séparation des Essences Végétales, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
| | - Lionel Ripoll
- Laboratoire d’Analyse et de Séparation des Essences Végétales, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
- Centre de Recherche sur la Boréalie, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
| | - Mouadh Mihoub
- Laboratoire d’Analyse et de Séparation des Essences Végétales, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
| | - Doria Grimard
- Laboratoire de Microbiologie, Complexe Hospitalier de la Sagamie, Chicoutimi, QC, Canada
| | - Jean Legault
- Laboratoire d’Analyse et de Séparation des Essences Végétales, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
- Centre de Recherche sur la Boréalie, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
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Richter P, Krüger M, Prasad B, Gastiger S, Bodenschatz M, Wieder F, Burkovski A, Geißdörfer W, Lebert M, Strauch SM. Using Colistin as a Trojan Horse: Inactivation of Gram-Negative Bacteria with Chlorophyllin. Antibiotics (Basel) 2019; 8:E158. [PMID: 31547053 PMCID: PMC6963628 DOI: 10.3390/antibiotics8040158] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/15/2019] [Accepted: 09/17/2019] [Indexed: 12/11/2022] Open
Abstract
Colistin (polymyxin E) is a membrane-destabilizing antibiotic used against Gram-negative bacteria. We have recently reported that the outer membrane prevents the uptake of antibacterial chlorophyllin into Gram-negative cells. In this study, we used sub-toxic concentrations of colistin to weaken this barrier for a combination treatment of Escherichia coli and Salmonella enterica serovar Typhimurium with chlorophyllin. In the presence of 0.25 µg/mL colistin, chlorophyllin was able to inactivate both bacteria strains at concentrations of 5-10 mg/L for E. coli and 0.5-1 mg/L for S. Typhimurium, which showed a higher overall susceptibility to chlorophyllin treatment. In accordance with a previous study, chlorophyllin has proven antibacterial activity both as a photosensitizer, illuminated with 12 mW/cm2, and in darkness. Our data clearly confirmed the relevance of the outer membrane in protection against xenobiotics. Combination treatment with colistin broadens chlorophyllin's application spectrum against Gram-negatives and gives rise to the assumption that chlorophyllin together with cell membrane-destabilizing substances may become a promising approach in bacteria control. Furthermore, we demonstrated that colistin acts as a door opener even for the photodynamic inactivation of colistin-resistant (mcr-1-positive) E. coli cells by chlorophyllin, which could help us to overcome this antimicrobial resistance.
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Affiliation(s)
- Peter Richter
- Cell Biology Division, Department of Biology, Friedrich-Alexander University Erlangen-Nuremberg, Staudtstraße 5, 91058 Erlangen, Germany.
| | - Marcus Krüger
- Clinic for Plastic, Aesthetic and Hand Surgery, Otto von Guericke University Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany.
| | - Binod Prasad
- Cell Biology Division, Department of Biology, Friedrich-Alexander University Erlangen-Nuremberg, Staudtstraße 5, 91058 Erlangen, Germany.
| | - Susanne Gastiger
- Microbiology Division, Department of Biology, Friedrich-Alexander University Erlangen-Nuremberg, Staudtstraße 5, 91058 Erlangen, Germany.
| | - Mona Bodenschatz
- Microbiology Division, Department of Biology, Friedrich-Alexander University Erlangen-Nuremberg, Staudtstraße 5, 91058 Erlangen, Germany.
| | - Florian Wieder
- Cell Biology Division, Department of Biology, Friedrich-Alexander University Erlangen-Nuremberg, Staudtstraße 5, 91058 Erlangen, Germany.
| | - Andreas Burkovski
- Microbiology Division, Department of Biology, Friedrich-Alexander University Erlangen-Nuremberg, Staudtstraße 5, 91058 Erlangen, Germany.
| | - Walter Geißdörfer
- Microbiological Diagnostics, Clinical Microbiology, Immunology and Hygiene, University Hospital Erlangen, Wasserturmstraße 3/5, 91054 Erlangen, Germany.
| | - Michael Lebert
- Cell Biology Division, Department of Biology, Friedrich-Alexander University Erlangen-Nuremberg, Staudtstraße 5, 91058 Erlangen, Germany.
| | - Sebastian M Strauch
- Postgraduate Program in Health and Environment, University of Joinville Region, Rua Paulo Malschitzki, 10, Joinville 89219-710, Brazil.
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Zhong C, Liu T, Gou S, He Y, Zhu N, Zhu Y, Wang L, Liu H, Zhang Y, Yao J, Ni J. Design and synthesis of new N-terminal fatty acid modified-antimicrobial peptide analogues with potent in vitro biological activity. Eur J Med Chem 2019; 182:111636. [PMID: 31466017 DOI: 10.1016/j.ejmech.2019.111636] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 08/12/2019] [Accepted: 08/19/2019] [Indexed: 12/25/2022]
Abstract
Developing novel antimicrobial agents is a top priority in fighting against bacterial resistance. Thus, a series of new monomer and dimer peptides were designed and synthesized by conjugating fatty acids at the N-terminus of partial d-amino acid substitution analogues of anoplin and dimerization. The new peptides exhibited more efficient killing of gram-negative and gram-positive bacteria, including methicillin-resistant Staphylococcus aureus compared with the parent peptide anoplin, and the dimer peptides were superior to the monomer peptides. It was important that the new peptides displayed low impact on bacterial resistance development. In addition, the antimicrobial activities were not significantly influenced by a physiological salt environment. They also presented high stability in the presence of protease or serum. Almost all of the new peptides had better selectivity towards anionic bacterial membranes over zwitterionic mammalian cell membranes. Moreover, the new peptides displayed synergistic or additive effects when used together with the antibiotics rifampicin and polymyxin B. These results showed that the new peptides could also prevent the formation of bacterial biofilms. Furthermore, outer/inner membrane permeabilization and cytoplasmic membrane depolarization experiments revealed that the new peptides had strong membrane permeabilization and depolarization. Confocal laser scanning microscopy, flow cytometry analysis and scanning electron microscopy further demonstrated that the new peptides could damage the integrity of the bacterial membrane. Finally, a DNA-binding affinity assay showed that the new peptides could bind to bacterial DNA. In summary, the conjugation of fatty acids at the N-terminus of peptides and dimerization are promising strategies for obtaining potent antimicrobial agents.
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Affiliation(s)
- Chao Zhong
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, China; School of Pharmacy, Lanzhou University, Lanzhou, 730000, China
| | - Tianqi Liu
- School of Pharmacy, Lanzhou University, Lanzhou, 730000, China
| | - Sanhu Gou
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, China; School of Pharmacy, Lanzhou University, Lanzhou, 730000, China
| | - Yongtao He
- School of Pharmacy, Lanzhou University, Lanzhou, 730000, China
| | - Ningyi Zhu
- School of Pharmacy, Lanzhou University, Lanzhou, 730000, China
| | - Yuewen Zhu
- School of Pharmacy, Lanzhou University, Lanzhou, 730000, China
| | - Li Wang
- School of Pharmacy, Lanzhou University, Lanzhou, 730000, China
| | - Hui Liu
- School of Pharmacy, Lanzhou University, Lanzhou, 730000, China
| | - Yun Zhang
- School of Pharmacy, Lanzhou University, Lanzhou, 730000, China
| | - Jia Yao
- The First Hospital of Lanzhou University, Lanzhou, 730000, China
| | - Jingman Ni
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, China; School of Pharmacy, Lanzhou University, Lanzhou, 730000, China.
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Glueck M, Hamminger C, Fefer M, Liu J, Plaetzer K. Save the crop: Photodynamic Inactivation of plant pathogens I: bacteria. Photochem Photobiol Sci 2019; 18:1700-1708. [PMID: 31214675 DOI: 10.1039/c9pp00128j] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The ever growing world-population poses challenges concerning the need for more food free of pesticide residues. The most common means to control plant pathogens is through the application of pesticides, which raises concerns over safety for humans and the environment. Recently, Photodynamic Inactivation (PDI) of microorganisms using natural photosensitizers has shown itself to be a powerful tool to combat bacteria and fungi. This study investigates the efficacy of PDI against the Gram(+) bacterial plant pathogen Rhodococcus fascians and Gram(-) Xanthomonas axonopodis and Erwinia amylovora using two chlorin e6 derivatives as photosensitizers: anionic sodium magnesium chlorophyllin (Chl, approved as food additive E140) in combination with cell wall permeabilizing agents (Na2EDTA or Polyaspartic acid sodium salt (PA)) and B17-0024, a mixture of chlorin e6 derivatives with cationic moieties at physiological pH. Both photosensitizers show excellent efficacy against R. fascians, whereby B17-0024 is phototoxic at a one order of magnitude lower concentration than Chl (10 μM B17-0024: relative inactivation (r.i.) >7.5 × 106, 100 μM Chl: r.i. 2.2 × 106, illumination with 26.6 J cm-2, 395 nm). The phototreatment of Gram(-) bacteria with Chl requires the obligatory use of cell wall permeabilizing agents like Na2EDTA (X. axonopodis) or PA (E. amylovora) to induce significant killing (more than 7 log units at 100 μM). On the other hand, B17-0024 proves to be a highly effective photosensitizer inducing bacterial inactivation at very low concentrations (10 μM for R. fascians and X. axonopodis, 100 μM for E. amylovora) without additives. In summary, PDI using both the natural photosensitizer Chl in combination with cell wall permeabilizing agents is effective and environmentally friendly. As an alternative, B17-0024 is highly photoactive against all model strains tested - even without cell wall permeabilizing agents. The photodynamic approach based on chlorin e6 derivatives should add to the growers' toolbox as a preferred alternative for the control of phytopathogens.
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Affiliation(s)
- Michael Glueck
- Laboratory of Photodynamic Inactivation of Microorganisms, Department of Biosciences, University of Salzburg, Hellbrunnerstr. 34, Salzburg, Austria.
| | - Christoph Hamminger
- Laboratory of Photodynamic Inactivation of Microorganisms, Department of Biosciences, University of Salzburg, Hellbrunnerstr. 34, Salzburg, Austria.
| | - Michael Fefer
- Suncor AgroScience, 2489 North Sheridan Way, Mississauga Ontario, L5K1A8, Canada
| | - Jun Liu
- Suncor AgroScience, 2489 North Sheridan Way, Mississauga Ontario, L5K1A8, Canada
| | - Kristjan Plaetzer
- Laboratory of Photodynamic Inactivation of Microorganisms, Department of Biosciences, University of Salzburg, Hellbrunnerstr. 34, Salzburg, Austria.
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Ullmann IF, Tunsjø HS, Andreassen M, Nielsen KM, Lund V, Charnock C. Detection of Aminoglycoside Resistant Bacteria in Sludge Samples From Norwegian Drinking Water Treatment Plants. Front Microbiol 2019; 10:487. [PMID: 30918503 PMCID: PMC6424899 DOI: 10.3389/fmicb.2019.00487] [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: 09/06/2018] [Accepted: 02/25/2019] [Indexed: 02/01/2023] Open
Abstract
Through a culture-based approach using sludge from drinking water treatment plants, this study reports on the presence of aminoglycoside resistant bacteria at 23 different geographical locations in Norway. Sludge samples are derived from a large environmental area including drinking water sources and their surrounding catchment areas. Aminoglycoside resistant bacteria were detected at 18 of the sample sites. Only five samples did not show any growth of isolates resistant to the selected aminoglycosides, kanamycin and gentamycin. There was a statistically significant correlation between the numbers of kanamycin and gentamycin resistant bacteria isolated from the 23 samples, perhaps suggesting common determinants of resistance. Based on 16S rRNA sequencing of 223 aminoglycoside resistant isolates, three different genera of Bacteroidetes were found to dominate across samples. These were Flavobacterium, Mucilaginibacter and Pedobacter. Further phenotypic and genotypic analyses showed that efflux pumps, reduced membrane permeability and four assayed genes coding for aminoglycoside modifying enzymes AAC(6′)-Ib, AAC(3′)-II, APH(3′)-II, APH(3′)-III, could only explain the resistance of a few of the isolates selected for testing. aph(3′)-II was detected in 1.6% of total isolates, aac(6′)-Ib and aph(3′)-III in 0.8%, while aac(3′)-II was not detected in any of the isolates. The isolates, for which potential resistance mechanisms were found, represented 13 different genera suggesting that aminoglycoside resistance is widespread in bacterial genera indigenous to sludge. The present study suggests that aminoglycoside resistant bacteria are present in Norwegian environments with limited anthropogenic exposures. However, the resistance mechanisms remain largely unknown, and further analyses, including culture-independent methods, could be performed to investigate other potential resistance mechanisms. This is, to our knowledge, the first large scale nationwide investigation of aminoglycoside resistance in the Norwegian environment.
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Affiliation(s)
- Ingvild F Ullmann
- Department of Life Sciences and Health, OsloMet - Oslo Metropolitan University, Oslo, Norway
| | - Hege S Tunsjø
- Department of Life Sciences and Health, OsloMet - Oslo Metropolitan University, Oslo, Norway
| | - Monica Andreassen
- Department of Zoonotic, Food- and Waterborne Infections, Norwegian Institute of Public Health, Oslo, Norway
| | - Kaare Magne Nielsen
- Department of Life Sciences and Health, OsloMet - Oslo Metropolitan University, Oslo, Norway
| | - Vidar Lund
- Department of Zoonotic, Food- and Waterborne Infections, Norwegian Institute of Public Health, Oslo, Norway
| | - Colin Charnock
- Department of Life Sciences and Health, OsloMet - Oslo Metropolitan University, Oslo, Norway
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A permeability-increasing drug synergizes with bacterial efflux pump inhibitors and restores susceptibility to antibiotics in multi-drug resistant Pseudomonas aeruginosa strains. Sci Rep 2019; 9:3452. [PMID: 30837499 PMCID: PMC6401119 DOI: 10.1038/s41598-019-39659-4] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 01/28/2019] [Indexed: 01/06/2023] Open
Abstract
Resistance to antibiotics poses a major global threat according to the World Health Organization. Restoring the activity of existing drugs is an attractive alternative to address this challenge. One of the most efficient mechanisms of bacterial resistance involves the expression of efflux pump systems capable of expelling antibiotics from the cell. Although there are efflux pump inhibitors (EPIs) available, these molecules are toxic for humans. We hypothesized that permeability-increasing antimicrobial peptides (AMPs) could lower the amount of EPI necessary to sensitize bacteria to antibiotics that are efflux substrates. To test this hypothesis, we measured the ability of polymyxin B nonapeptide (PMBN), to synergize with antibiotics in the presence of EPIs. Assays were performed using planktonic and biofilm-forming cells of Pseudomonas aeruginosa strains overexpressing the MexAB-OprM efflux system. Synergy between PMBN and EPIs boosted azithromycin activity by a factor of 2,133 and sensitized P. aeruginosa to all tested antibiotics. This reduced several orders of magnitude the amount of inhibitor needed for antibiotic sensitization. The selected antibiotic-EPI-PMBN combination caused a 10 million-fold reduction in the viability of biofilm forming cells. We proved that AMPs can synergize with EPIs and that this phenomenon can be exploited to sensitize bacteria to antibiotics.
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Qiao J, Purro M, Liu Z, Xiong MP. Terpyridine-Micelles for Inhibiting Bacterial Biofilm Development. ACS Infect Dis 2018; 4:1346-1354. [PMID: 29974746 DOI: 10.1021/acsinfecdis.8b00091] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Iron plays a critical role in bacterial infections and is especially critical for supporting biofilm formation. Until recently, Fe(III) was assumed to be the most relevant form of iron to chelate in therapeutic antimicrobial strategies due to its natural abundance under normal oxygen and physiologic conditions. Recent clinical data obtained from cystic fibrosis (CF) patients found that there is actually quite an abundance of Fe(II) present in sputum and that there exists a significant relationship between sputum Fe(II) concentration and severity of the disease. A biocompatible mixed micelle formed from the self-assembly of poly(lactic- co-glycolic acid)- block-methoxy poly(ethylene glycol) (PLGA- b-mPEG) and poly(lactic- co-glycolic acid)- block-poly(terpyridine)5 [PLGA- b-p(Tpy)5] polymers was prepared to chelate Fe(II) (Tpy-micelle). Tpy-micelles showed high selectivity for Fe(II) over Fe(III), decreased biofilm mass more effectively under anaerobic conditions at >4 μM Tpy-micelles, reduced bacteria growth in biofilms by >99.9% at 128 μM Tpy-micelles, effectively penetrated throughout a 1-day old biofilm, and inhibited biofilm development in a concentration-dependent manner. This study reveals that Fe(II) chelating Tpy-micelles are a promising addition to Fe(III) chelating strategies to inhibit biofilm formation in CF lung infections.
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Affiliation(s)
- Jing Qiao
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, 250 W. Green Street, Athens, Georgia 30602-2352, United States
| | - Max Purro
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, 250 W. Green Street, Athens, Georgia 30602-2352, United States
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin−Madison, 777 Highland Avenue, Madison, Wisconsin 53705-2222, United States
| | - Zhi Liu
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, 250 W. Green Street, Athens, Georgia 30602-2352, United States
| | - May P. Xiong
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, 250 W. Green Street, Athens, Georgia 30602-2352, United States
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Elhagrassy AF. Isolation and characterization of actinomycetes from Mural paintings of Snu- Sert-Ankh tomb, their antimicrobial activity, and their biodeterioration. Microbiol Res 2018; 216:47-55. [PMID: 30269856 DOI: 10.1016/j.micres.2018.08.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 08/02/2018] [Accepted: 08/10/2018] [Indexed: 11/18/2022]
Abstract
A total of 35 actinomycetes were isolated from the surface of mural paintings of snu- sort- ankh in El Leasht, Egypt during four seasons all over 2016-2017. In 2009 this tomb was deteriorated by "Aspergillus niger, A. flavus, Fusarium moniliforme, Alternaria alternate, Rhizopus stolonifera, Bacillus subtilis, Bacillus cereus, and micrococcus iuteus." In 2017 the isolation of swabs presents only Aspergillus niger and about 35 actinomycetes classified to three different groups "Streptomyces, Nocardia, and Micromonospora" only five species belong to Streptomyces group showed antimicrobial activity against the previous microorganisms. These actinomycetes were identified according to their sequences in the GenBank to "Streptomyces spectabilis, S. alborgriseolus, S. globsus, S. corchorstt, S. ambofactens." In the other hand, the pigments of the wall paintings of the tomb (Egyptian blue, Egyptian green, Goethite) that analyzed by SEM-EDX, FTIR were measured by the spectrophotometer in both 2009 and 2017. The results showed that the actinomycetes could produce extracellular pigments causing a color change of archaeological pigments otherwise it helps in inhibition the growth of the previous microorganisms found in 2009. The optimization factors for increasing the antibiotic production of the Streptomyces were 3% NaCl and temperature between 30:35°c in Alkin pH (pH = 7.5).
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Affiliation(s)
- Abeer F Elhagrassy
- Lecturer of Mural paintings and microbiology, Conservation Department, Faculty of Archaeology, Fayoum University, Egypt.
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Mousavi Khaneghah A, Hashemi SMB, Eş I, Fracassetti D, Limbo S. Efficacy of Antimicrobial Agents for Food Contact Applications: Biological Activity, Incorporation into Packaging, and Assessment Methods: A Review. J Food Prot 2018; 81:1142-1156. [PMID: 29939788 DOI: 10.4315/0362-028x.jfp-17-509] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Interest in the utilization of antimicrobial active packaging for food products has increased in recent years. Antimicrobial active packaging involves the incorporation of antimicrobial compounds into packaging materials, with the aim of maintaining or extending food quality and shelf life. Plant extracts, essential oils, organic acids, bacteriocins, inorganic substances, enzymes, and proteins are used as antimicrobial agents in active packaging. Evaluation of the antimicrobial activity of packaging materials using different methods has become a critical issue for both food safety and the commercial utilization of such packaging technology. This article reviews the different types of antimicrobial agents used for active food packaging materials, the main incorporation techniques, and the assessment methods used to examine the antimicrobial activity of packaging materials, taking into account their safety as food contact materials.
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Affiliation(s)
| | | | - Ismail Eş
- 3 Department of Material and Bioprocess Engineering, Faculty of Chemical Engineering, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil (ORCID: http://orcid.org/0000-0001-5769-0004 [A.M.K.])
| | - Daniela Fracassetti
- 4 Department of Food Environmental and Nutritional Sciences, Università degli Studi di Milano, Milan 20123, Italy (ORCID: http://orcid.org/0000-0002-4739-4751 [S.L.])
| | - Sara Limbo
- 4 Department of Food Environmental and Nutritional Sciences, Università degli Studi di Milano, Milan 20123, Italy (ORCID: http://orcid.org/0000-0002-4739-4751 [S.L.])
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Karumathil DP, Nair MS, Gaffney J, Kollanoor-Johny A, Venkitanarayanan K. Trans-Cinnamaldehyde and Eugenol Increase Acinetobacter baumannii Sensitivity to Beta-Lactam Antibiotics. Front Microbiol 2018; 9:1011. [PMID: 29875743 PMCID: PMC5974060 DOI: 10.3389/fmicb.2018.01011] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 04/30/2018] [Indexed: 01/23/2023] Open
Abstract
Multi-drug resistant (MDR) Acinetobacter baumannii is a major nosocomial pathogen causing a wide range of clinical conditions with significant mortality rates. A. baumannii strains are equipped with a multitude of antibiotic resistance mechanisms, rendering them resistant to most of the currently available antibiotics. Thus, there is a critical need to explore novel strategies for controlling antibiotic resistance in A. baumannii. This study investigated the efficacy of two food-grade, plant-derived antimicrobials (PDAs), namely trans-cinnamaldehyde (TC) and eugenol (EG) in decreasing A. baumannii’s resistance to seven β-lactam antibiotics, including ampicillin, methicillin, meropenem, penicillin, aztreonam, amoxicillin, and piperacillin. Two MDR A. baumannii isolates (ATCC 17978 and AB 251847) were separately cultured in tryptic soy broth (∼6 log CFU/ml) containing the minimum inhibitory concentration (MIC) of TC or EG with or without the MIC of each antibiotic at 37°C for 18 h. A. baumannii strains not exposed to the PDAs or antibiotics served as controls. Following incubation, A. baumannii counts were determined by broth dilution assay. In addition, the effect of PDAs on the permeability of outer membrane and efflux pumps in A. baumannii was measured. Further, the effect of TC and EG on the expression of A. baumannii genes encoding resistance to β-lactam antibiotics (blaP), efflux pumps (adeABC), and multi-drug resistant protein (mdrp) was studied using real-time quantitative PCR (RT-qPCR). The experiment was replicated three times with duplicate samples of each treatment and control. The results from broth dilution assay indicated that both TC and EG in combination with antibiotics increased the sensitivity of A. baumannii to all the tested antibiotics (P < 0.05). The two PDAs inhibited the function of A. baumannii efflux pump, (AdeABC), but did not increase the permeability of its outer membrane. Moreover, RT-qPCR data revealed that TC and EG down-regulated the expression of majority of the genes associated with β-lactam antibiotic resistance, especially blaP and adeABC (P < 0.05). The results suggest that TC and EG could potentially be used along with β-lactam antibiotics for controlling MDR A. baumannii infections; however, their clinical significance needs to be determined using in vivo studies.
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Affiliation(s)
- Deepti P Karumathil
- Department of Animal Science, University of Connecticut, Storrs, CT, United States
| | - Meera Surendran Nair
- Department of Animal Science, University of Connecticut, Storrs, CT, United States
| | - James Gaffney
- College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
| | - Anup Kollanoor-Johny
- Department of Animal Science, University of Minnesota, Saint Paul, MN, United States
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Alborzi S, Bastarrachea LJ, Ding Q, Tikekar RV. Inactivation of Escherichia Coli O157:H7 and Listeria Innocua by Benzoic Acid, Ethylenediaminetetraacetic Acid and Their Combination in Model Wash Water and Simulated Spinach Washing. J Food Sci 2018; 83:1032-1040. [PMID: 29488632 DOI: 10.1111/1750-3841.14077] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 01/09/2018] [Accepted: 01/15/2018] [Indexed: 11/27/2022]
Abstract
An antimicrobial effect of benzoic acid (BA) and ethylenediaminetetraacetic acid (EDTA) was evaluated as a potential antimicrobial treatment against Escherichia coli O157:H7 and Listeria innocua. A 30 min exposure to the combination of 15 mM BA and 1 mM EDTA at 22 °C resulted in approximately 3 logarithmic reductions in stationary phase E. coli O157:H7. Logarithmic phase E. coli O157:H7 was more sensitive (P < 0.05) to the treatment and 1 mM EDTA alone caused more than 5 logarithmic reductions. L. innocua was also sensitive to a treatment with 15 mM BA alone, which induced 5 logarithmic reductions. By increasing the temperature of the solution containing 15 mM BA and 1 mM EDTA to 40 °C, more than 5 logarithmic reductions in stationary phase E. coli O157:H7 was observed after 5 min of treatment. However, the antimicrobial effect was attenuated (reaching less than 1 logarithmic reductions) at 4 °C. In addition, the combined BA and EDTA treatment retained its antimicrobial effect against E. coli O157:H7 for at least 6 cycles of treatment over 6 days at room temperature (22 °C). In a simulated spinach washing study, 15 mM BA and 1 mM EDTA together were able to prevent cross-contamination of E. coli O157:H7. The results highlight the potential use of combination of BA (15 mM) and EDTA (1 mM) to address microbial risk from E. coli O157:H7 and L. innocua in fresh produce industry. PRACTICAL APPLICATION This study demonstrates the effectiveness of benzoic acid (BA) and EDTA mixture in inactivating bacteria in the water used for produce washing and reducing the incidence of cross-contamination during washing of fresh produce. Use of BA + EDTA mixture has significant benefits such as: (a) ability to be reused, (b) effectiveness in the presence of organic matter, and (c) reduced need of monitoring wash water conditions such as pH, concentration and organic matter.
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Affiliation(s)
- Solmaz Alborzi
- Dept. of Nutrition and Food Science, Univ. of Maryland, College Park, MD 20742, U.S.A
| | - Luis J Bastarrachea
- Dept. of Nutrition, Dietetics, and Food Sciences, Utah State Univ., Logan, UT 84322, U.S.A
| | - Qiao Ding
- Dept. of Nutrition and Food Science, Univ. of Maryland, College Park, MD 20742, U.S.A
| | - Rohan V Tikekar
- Dept. of Nutrition and Food Science, Univ. of Maryland, College Park, MD 20742, U.S.A
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Bacterial and fungal biodeterioration of discolored building paints in Lagos, Nigeria. World J Microbiol Biotechnol 2017; 33:196. [DOI: 10.1007/s11274-017-2362-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 09/27/2017] [Indexed: 02/05/2023]
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Strieth D, Schwing J, Kuhne S, Lakatos M, Muffler K, Ulber R. A semi-continuous process based on an ePBR for the production of EPS using Trichocoleus sociatus. J Biotechnol 2017; 256:6-12. [DOI: 10.1016/j.jbiotec.2017.06.1205] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 06/29/2017] [Indexed: 01/02/2023]
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Lytou AE, Panagou EZ, Nychas GJE. Effect of different marinating conditions on the evolution of spoilage microbiota and metabolomic profile of chicken breast fillets. Food Microbiol 2017; 66:141-149. [PMID: 28576362 DOI: 10.1016/j.fm.2017.04.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Revised: 04/05/2017] [Accepted: 04/11/2017] [Indexed: 10/19/2022]
Abstract
Five different marinades were prepared containing lemon juice, apple cider vinegar, pomegranate juice and combinations of them. Three different temperatures (4, 10, and 20 °C) and five marinating time intervals (1, 3, 6, and 9 h) were tested. Microbial, physicochemical as well as sensory analyses were performed to assess marination. Noticeable microbial reductions and satisfactory sensory results were observed only in samples treated for short time (1 and 3 h). The marinade in which pomegranate and lemon juices were combined caused a decrease in microbial counts and led to desirable sensory attributes. Each of the marinades was characterized by a distinguishable organic acid profile, while the discrimination of the samples, based on organic acid concentration, between low (1 and 3) and high (6 and 9) marinating time was feasible. It can be concluded that marinating time affected the indigenous microbiota and the sensory characteristics of chicken meat while pomegranate could be a promising marinating ingredient from a microbiological and physicochemical perspective.
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Affiliation(s)
- Anastasia E Lytou
- Laboratory of Microbiology and Biotechnology of Foods, Department of Food Science and Human Nutrition, Faculty of Foods, Biotechnology and Development, Agricultural University of Athens (AUA), Iera Odos 75, Athens 11855, Greece
| | - Efstathios Z Panagou
- Laboratory of Microbiology and Biotechnology of Foods, Department of Food Science and Human Nutrition, Faculty of Foods, Biotechnology and Development, Agricultural University of Athens (AUA), Iera Odos 75, Athens 11855, Greece
| | - George-John E Nychas
- Laboratory of Microbiology and Biotechnology of Foods, Department of Food Science and Human Nutrition, Faculty of Foods, Biotechnology and Development, Agricultural University of Athens (AUA), Iera Odos 75, Athens 11855, Greece.
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Kirchhoff C, Cypionka H. Boosted Membrane Potential as Bioenergetic Response to Anoxia in Dinoroseobacter shibae. Front Microbiol 2017; 8:695. [PMID: 28473821 PMCID: PMC5397407 DOI: 10.3389/fmicb.2017.00695] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 04/04/2017] [Indexed: 11/29/2022] Open
Abstract
Dinoroseobacter shibae DFL 12T is a metabolically versatile member of the world-wide abundant Roseobacter clade. As an epibiont of dinoflagellates D. shibae is subjected to rigorous changes in oxygen availability. It has been shown that it loses up to 90% of its intracellular ATP when exposed to anoxic conditions. Yet, D. shibae regenerates its ATP level quickly when oxygen becomes available again. In the present study we focused on the bioenergetic aspects of the quick recovery and hypothesized that the proton-motive force decreases during anoxia and gets restored upon re-aeration. Therefore, we analyzed ΔpH and the membrane potential (ΔΨ) during the oxic-anoxic transitions. To visualize changes of ΔΨ we used fluorescence microscopy and the carbocyanine dyes DiOC2 (3; 3,3′-Diethyloxacarbocyanine Iodide) and JC-10. In control experiments the ΔΨ-decreasing effects of the chemiosmotic inhibitors CCCP (carbonyl cyanide m-chlorophenyl hydrazone), TCS (3,3′,4′,5-tetrachlorosalicylanilide) and gramicidin were tested on D. shibae and Gram-negative and -positive control bacteria (Escherichia coli and Micrococcus luteus). We found that ΔpH is not affected by short-term anoxia and does not contribute to the quick ATP regeneration in D. shibae. By contrast, ΔΨ was increased during anoxia, which was astonishing since none of the control organisms behaved that way. Our study shows physiological and bioenergetical aspects comparing to previous studies on transcriptomic responses to the transition from aerobic to nitrate respiration in D. shibae. For the lifestyle as an epibiont of a dinoflagellate, the ability to stand phases of temporary oxygen depletion is beneficial. With a boosted ΔΨ, the cells are able to give their ATP regeneration a flying start, once oxygen is available again.
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Affiliation(s)
- Christian Kirchhoff
- Institute for Chemistry and Biology of the Marine Environment, Carl-von-Ossietzky University of OldenburgOldenburg, Germany
| | - Heribert Cypionka
- Institute for Chemistry and Biology of the Marine Environment, Carl-von-Ossietzky University of OldenburgOldenburg, Germany
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Advances in the treatment of problematic industrial biofilms. World J Microbiol Biotechnol 2017; 33:97. [PMID: 28409363 DOI: 10.1007/s11274-016-2203-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 12/28/2016] [Indexed: 02/02/2023]
Abstract
In nature, microorganisms tend to form biofilms that consist of extracellular polymeric substances with embedded sessile cells. Biofilms, especially mixed-culture synergistic biofilm consortia, are notoriously difficult to treat. They employ various defense mechanisms against attacks from antimicrobial agents. Problematic industrial biofilms cause biofouling as well as biocorrosion, also known as microbiologically influenced corrosion. Biocides are often used to treat biofilms together with scrubbing or pigging. Unfortunately, chemical treatments suppress vulnerable microbial species while allowing resistant species to take over. Repeated treatment cycles are typically needed in biofilm mitigation. This leads to biocide dosage escalation, causing environmental problems, higher costs and sometimes operational problems such as scale formation. New treatment methods are being developed such as enhanced biocide treatment and bacteriophage treatment. Special materials such as antibacterial stainless steels are also being created to combat biofilms. This review discussed some of the advances made in the fight against problematic industrial biofilms.
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Weinkauf H, Brehm-Stecher B. Sodium Polyphosphate and Polyethylenimine Enhance the Antimicrobial Activities of Plant Essential Oils. SCIENCEOPEN RESEARCH 2016. [DOI: 10.14293/s2199-1006.1.sor-life.z72tp0.v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
<p>Plant extracts have been used for millennia for treatment of disease, with much recent interest focusing on the antimicrobial activities of plant essential oils (EOs). Although EOs are active against common microbial pathogens, their effective use as topical, environmental or food antimicrobials will require EO-based formulations with enhanced antimicrobial activities. In the present study, two polyionic compounds, sodium polyphosphate (polyP, a polyanion) and polyethylenimine (PEI, a polycation), were evaluated for their abilities to enhance the antimicrobial activities of six EOs against the human pathogens <em>Escherichia coli</em> O157:H7, <em>Salmonella enterica</em> subsp. <em>enterica </em>ser Minnesota, <em>Pseudomonas aeruginosa</em>, <em>Listeria monocytogenes</em>, <em>Staphylococcus aureus </em>and <em>Candida albicans</em>. EOs tested were cinnamon, clove, regular and redistilled oregano and two types of thyme oil. EOs were examined via disk diffusion and broth microdilution, either alone or in the presence of sub-inhibitory levels of polyP or PEI. Both polyP and PEI were found to be effective enhancers of EO activity against all strains examined, and calculation of fractional inhibitory indices for select EO/organism pairings demonstrated that true synergy was possible with this enhancement approach. Experiments with a deep rough strain of S. Minnesota probed the role of the outer membrane in both intrinsic resistance to EOs and enhancement by polyions. The use of polyP and PEI for boosting the antimicrobial activities of EOs may eventually facilitate the development of more effective EO-based antimicrobial treatments for use in applications such as wound treatment, surface disinfection, or as GRAS antimicrobials for use in foods or on food contact surfaces.</p>
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Coutinho ML, Miller AZ, Martin-Sanchez PM, Mirão J, Gomez-Bolea A, Machado-Moreira B, Cerqueira-Alves L, Jurado V, Saiz-Jimenez C, Lima A, Phillips AJL, Pina F, Macedo MF. A multiproxy approach to evaluate biocidal treatments on biodeteriorated majolica glazed tiles. Environ Microbiol 2016; 18:4794-4816. [PMID: 27235544 DOI: 10.1111/1462-2920.13380] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 05/17/2016] [Indexed: 02/02/2023]
Abstract
The Fishing House located on the grounds of the Marquis of Pombal Palace, Oeiras, Portugal, was built in the 18th century. During this epoch, Portuguese gardens, such as the one surrounding the Fishing House, were commonly ornamented with glazed wall tile claddings. Currently, some of these outdoor tile panels are covered with dark colored biofilms, contributing to undesirable aesthetic changes and eventually inducing chemical and physical damage to the tile surfaces. Phylogenetic analyses revealed that the investigated biofilms are mainly composed of green algae, cyanobacteria and dematiaceous fungi. With the aim of mitigating biodeterioration, four different biocides (TiO2 nanoparticles, Biotin® T, Preventol® RI 80 and Albilex Biostat® ) were applied in situ to the glazed wall tiles. Their efficacy was monitored by visual examination, epifluorescence microscopy and DNA-based analysis. Significant changes in the microbial community composition were observed 4 months after treatment with Preventol® RI 80 and Biotin® T. Although the original community was inactivated after these treatments, an early stage of re-colonization was detected 6 months after the biocide application. TiO2 nanoparticles showed promising results due to their self-cleaning effect, causing the detachment of the biofilm from the tile surface, which remained clean 6 and even 24 months after biocide application. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.
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Affiliation(s)
- M L Coutinho
- LAQV-REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Lisboa, Portugal.,Departamento de Conservação e Restauro, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Monte de Caparica, Lisboa, Portugal.,Research Unit VICARTE (Vidro e Cerâmica para as Artes), Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Monte de Caparica, Lisboa, Portugal
| | - A Z Miller
- Instituto de Recursos Naturales y Agrobiologia de Sevilla, IRNAS-CSIC, Sevilla, Spain
| | - P M Martin-Sanchez
- BAM - Federal Institute for Materials Research and Testing, Division 4.1 Biodeterioration and Reference Organisms, Berlin, Germany
| | - J Mirão
- Laboratório HÉRCULES, Escola de Ciências e Tecnologia, Universidade de Évora, Évora, Portugal
| | - A Gomez-Bolea
- Department of Plant Biology (Botany), Facultat de Biologia, Universitat de Barcelona, 08028, Barcelona, Spain
| | - B Machado-Moreira
- CERENA, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - L Cerqueira-Alves
- C2TN, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - V Jurado
- Instituto de Recursos Naturales y Agrobiologia de Sevilla, IRNAS-CSIC, Sevilla, Spain
| | - C Saiz-Jimenez
- Instituto de Recursos Naturales y Agrobiologia de Sevilla, IRNAS-CSIC, Sevilla, Spain
| | - A Lima
- Departamento de Conservação e Restauro, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Monte de Caparica, Lisboa, Portugal.,Research Unit VICARTE (Vidro e Cerâmica para as Artes), Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Monte de Caparica, Lisboa, Portugal
| | - A J L Phillips
- UCIBIO, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Monte de Caparica, Lisboa, Portugal
| | - F Pina
- LAQV-REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Lisboa, Portugal
| | - M F Macedo
- Departamento de Conservação e Restauro, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Monte de Caparica, Lisboa, Portugal.,Research Unit VICARTE (Vidro e Cerâmica para as Artes), Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Monte de Caparica, Lisboa, Portugal
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