1
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MacNair CR, Rutherford ST, Tan MW. Alternative therapeutic strategies to treat antibiotic-resistant pathogens. Nat Rev Microbiol 2024; 22:262-275. [PMID: 38082064 DOI: 10.1038/s41579-023-00993-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2023] [Indexed: 04/19/2024]
Abstract
Resistance threatens to render antibiotics - which are essential for modern medicine - ineffective, thus posing a threat to human health. The discovery of novel classes of antibiotics able to overcome resistance has been stalled for decades, with the developmental pipeline relying almost entirely on variations of existing chemical scaffolds. Unfortunately, this approach has been unable to keep pace with resistance evolution, necessitating new therapeutic strategies. In this Review, we highlight recent efforts to discover non-traditional antimicrobials, specifically describing the advantages and limitations of antimicrobial peptides and macrocycles, antibodies, bacteriophages and antisense oligonucleotides. These approaches have the potential to stem the tide of resistance by expanding the physicochemical property space and target spectrum occupied by currently approved antibiotics.
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Affiliation(s)
- Craig R MacNair
- Department of Infectious Diseases, Genentech Inc., South San Francisco, CA, USA
| | - Steven T Rutherford
- Department of Infectious Diseases, Genentech Inc., South San Francisco, CA, USA
| | - Man-Wah Tan
- Department of Infectious Diseases, Genentech Inc., South San Francisco, CA, USA.
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2
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Neto S, Vieira A, Oliveira H, Espiña B. Assessing Acinetobacter baumannii virulence and treatment with a bacteriophage using zebrafish embryos. FASEB J 2023; 37:e23013. [PMID: 37289094 DOI: 10.1096/fj.202300385r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 05/10/2023] [Accepted: 05/19/2023] [Indexed: 06/09/2023]
Abstract
Acinetobacter baumannii is the leading bacteria causative of nosocomial infections, with high fatality rates, mostly due to their multi-resistance to antibiotics. The capsular polysaccharide (k-type) is a major virulence factor. Bacteriophages are viruses that specifically infect bacteria and have been used to control drug-resistant bacterial pathogens. In particular, A. baumannii phages can recognize specific capsules, from a diversity of >125 that exist. This high specificity demands the in vivo identification of the most virulent A. baumannii k-types that need to be targeted by phage therapy. Currently, the zebrafish embryo has particularly attained interest for in vivo infection modeling. In this study, an A. baumannii infection was successfully established, through the bath immersion of tail-injured zebrafish embryos, to study the virulence of eight capsule types (K1, K2, K9, K32, K38, K44, K45, and K67). The model revealed itself as capable of discerning the most virulent (K2, K9, K32, and K45), middle (K1, K38, and K67), and the less virulent (K44) strains. Additionally, the infection of the most virulent strains was controlled in vivo resorting to the same technique, with previously identified phages (K2, K9, K32, and K45 phages). Phage treatments were able to increase the average survival from 35.2% to up to 74.1% (K32 strain). All the phages performed equally well. Collectively, the results show the potential of the model to not only evaluate virulence of bacteria such as A. baumannii but also assess novel treatments' effectiveness.
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Affiliation(s)
- Sofia Neto
- International Iberian Nanotechnology Laboratory (INL), Braga, Portugal
- CEB-Center of Biological Engineering, University of Minho, Braga, Portugal
- LABBELS-Associate Laboratory, Guimarães, Portugal
| | - Ana Vieira
- International Iberian Nanotechnology Laboratory (INL), Braga, Portugal
| | - Hugo Oliveira
- CEB-Center of Biological Engineering, University of Minho, Braga, Portugal
- LABBELS-Associate Laboratory, Guimarães, Portugal
| | - Begoña Espiña
- International Iberian Nanotechnology Laboratory (INL), Braga, Portugal
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3
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Liu H, Hu Z, Li M, Yang Y, Lu S, Rao X. Therapeutic potential of bacteriophage endolysins for infections caused by Gram-positive bacteria. J Biomed Sci 2023; 30:29. [PMID: 37101261 PMCID: PMC10131408 DOI: 10.1186/s12929-023-00919-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 04/14/2023] [Indexed: 04/28/2023] Open
Abstract
Gram-positive (G+) bacterial infection is a great burden to both healthcare and community medical resources. As a result of the increasing prevalence of multidrug-resistant G+ bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), novel antimicrobial agents must urgently be developed for the treatment of infections caused by G+ bacteria. Endolysins are bacteriophage (phage)-encoded enzymes that can specifically hydrolyze the bacterial cell wall and quickly kill bacteria. Bacterial resistance to endolysins is low. Therefore, endolysins are considered promising alternatives for solving the mounting resistance problem. In this review, endolysins derived from phages targeting G+ bacteria were classified based on their structural characteristics. The active mechanisms, efficacy, and advantages of endolysins as antibacterial drug candidates were summarized. Moreover, the remarkable potential of phage endolysins in the treatment of G+ bacterial infections was described. In addition, the safety of endolysins, challenges, and possible solutions were addressed. Notwithstanding the limitations of endolysins, the trends in development indicate that endolysin-based drugs will be approved in the near future. Overall, this review presents crucial information of the current progress involving endolysins as potential therapeutic agents, and it provides a guideline for biomaterial researchers who are devoting themselves to fighting against bacterial infections.
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Affiliation(s)
- He Liu
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University, Chongqing, 400038, China
| | - Zhen Hu
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University, Chongqing, 400038, China
| | - Mengyang Li
- Department of Microbiology, School of Medicine, Chongqing University, Chongqing, 400044, China
| | - Yi Yang
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University, Chongqing, 400038, China
| | - Shuguang Lu
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University, Chongqing, 400038, China.
| | - Xiancai Rao
- Department of Microbiology, College of Basic Medical Sciences, Key Laboratory of Microbial Engineering Under the Educational Committee in Chongqing, Army Medical University, Chongqing, 400038, China.
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4
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Interrogation of the contribution of (endo)lysin domains to tune their bacteriolytic efficiency provides a novel clue to design superior antibacterials. Int J Biol Macromol 2022; 223:1042-1053. [PMID: 36370862 DOI: 10.1016/j.ijbiomac.2022.11.043] [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: 08/16/2022] [Revised: 11/04/2022] [Accepted: 11/05/2022] [Indexed: 11/11/2022]
Abstract
Bacteriophage-derived endolysins and bacterial autolysins (hereinafter lysins) represent a completely new class of efficient antibacterials. They prevent the development of bacterial resistance and help protect commensal microbiota, producing cell wall lysis. Here we have investigated whether the acquisition of enzymatic active domains (EADs) and cell wall binding domains (CWBDs) of balancing efficiencies could be a way of tuning natural lysin activity. The concept was applied to produce a chimeric lysin of superior antibacterial capacity using the endolysin Skl and the major pneumococcal autolysin LytA. Combination of the Skl EAD and the cell wall choline-binding domain (CBD) of LytA in the chimera QSLA increased the bacterial killing by 2 logs or more compared to parental enzymes at an equal concentration and extended the substrate range to resistant and emergent pneumococci and other pathogens of the mitis group. Contrarily, QLAS, containing LytA EAD and Skl CBD, was inactive against all tested strains, although domain structures were preserved and hydrolysis of purified cell walls maintained in both chimeras. As a whole, our study provides a novel clue to design superior lysins to fight multidrug-resistant pathogens based on domain selection, and a powerful in-vivo active lysin (QSLA) with promising therapeutic perspectives.
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5
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Wong KY, Megat Mazhar Khair MH, Song AAL, Masarudin MJ, Chong CM, In LLA, Teo MYM. Endolysins against Streptococci as an antibiotic alternative. Front Microbiol 2022; 13:935145. [PMID: 35983327 PMCID: PMC9378833 DOI: 10.3389/fmicb.2022.935145] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 07/07/2022] [Indexed: 11/21/2022] Open
Abstract
Multi-drug resistance has called for a race to uncover alternatives to existing antibiotics. Phage therapy is one of the explored alternatives, including the use of endolysins, which are phage-encoded peptidoglycan hydrolases responsible for bacterial lysis. Endolysins have been extensively researched in different fields, including medicine, food, and agricultural applications. While the target specificity of various endolysins varies greatly between species, this current review focuses specifically on streptococcal endolysins. Streptococcus spp. causes numerous infections, from the common strep throat to much more serious life-threatening infections such as pneumonia and meningitis. It is reported as a major crisis in various industries, causing systemic infections associated with high mortality and morbidity, as well as economic losses, especially in the agricultural industry. This review highlights the types of catalytic and cell wall-binding domains found in streptococcal endolysins and gives a comprehensive account of the lytic ability of both native and engineered streptococcal endolysins studied thus far, as well as its potential application across different industries. Finally, it gives an overview of the advantages and limitations of these enzyme-based antibiotics, which has caused the term enzybiotics to be conferred to it.
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Affiliation(s)
- Kuan Yee Wong
- Department of Biotechnology, Faculty of Applied Sciences, UCSI University, Kuala Lumpur, Malaysia
| | - Megat Hamzah Megat Mazhar Khair
- Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Selangor, Malaysia
| | - Adelene Ai-Lian Song
- Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Selangor, Malaysia
| | - Mas Jaffri Masarudin
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Selangor, Malaysia
| | - Chou Min Chong
- Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, Selangor, Malaysia
| | - Lionel Lian Aun In
- Department of Biotechnology, Faculty of Applied Sciences, UCSI University, Kuala Lumpur, Malaysia
- Lionel Lian Aun In,
| | - Michelle Yee Mun Teo
- Department of Biotechnology, Faculty of Applied Sciences, UCSI University, Kuala Lumpur, Malaysia
- *Correspondence: Michelle Yee Mun Teo,
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6
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Kim J, Kim JC, Ahn J. Assessment of bacteriophage-encoded endolysin as a potent antimicrobial agent against antibiotic-resistant Salmonella Typhimurium. Microb Pathog 2022; 168:105576. [PMID: 35561980 DOI: 10.1016/j.micpath.2022.105576] [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: 02/17/2022] [Revised: 05/05/2022] [Accepted: 05/08/2022] [Indexed: 11/25/2022]
Abstract
This study was designed to evaluate the potential of using newly purified Salmonella phage-encoded endolysin LysPB32 as novel antibiotic alternative. The endolysin LysPB32 was characterized by analyzing pH and thermal stability, lytic spectrum, antimicrobial activity, and mutant frequency against Salmonella Typhimurium KCCM 40253 (STKCCM), S. Typhimurium ATCC 19585 (STATCC), S. Typhimurium CCARM 8009 (STCCARM), Klebsiella pneumoniae ATCC 23357 (KPATCC), K. pneumoniae CCARM 10237 (KPCCARM), Pseudomonas aeruginosa ATCC 27853 (PAATCC), Listeria monocytogenes ATCC 1911 (LMATCC), Staphylococcus aureus ATCC 25923 (SAATCC), and S. aureus CCARM 3080 (SACCARM). The molecular weight of LysPB32 is 17 kDa that was classified as N-acetyl-β-d-muramidase. The optimum activity of LysPB32 against the outer membrane (OM) permeabilized STKCCM, STATCC, and STCCARM was observed at 37 °C and pH 6.5. LysPB32 had a broad spectrum of muralytic activity against antibiotic-sensitive STKCCM (41 mOD/min), STATCC (32 mOD/min), and SBKACC (25 mOD/min) and antibiotic-resistant STCCARM (35 mOD/min) and KPCCARM (31 mOD/min). The minimum inhibitory concentrations (MICs) of polymyxin B against STKCCM, STCCARM, and STATCC were decreased by 4-, 4-, and 8-folds, respectively, when treated with LysPB32. The combination of LysPB32 and polymyxin B effectively inhibited the growth of STKCCM, STCCARM, and STATCC after 24 h of incubation at 37 °C, showing 4.9-, 4.4-, and 3.3-log reductions, respectively. The mutant frequency was low in STKCCM, STCCARM, and STATCC treated with combination of LysPB32-polymyxin B system. The results suggest the LysPB32-polymyxin system can be a potential candidate for alternative therapeutic agent to control antibiotic-resistant pathogens.
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Affiliation(s)
- Junhwan Kim
- Department of Biomedical Science and Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon, Gangwon, 24341, Republic of Korea
| | - Jin-Chul Kim
- Department of Biomedical Science and Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon, Gangwon, 24341, Republic of Korea
| | - Juhee Ahn
- Department of Biomedical Science and Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon, Gangwon, 24341, Republic of Korea.
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7
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Gallego-Páramo C, Hernández-Ortiz N, Buey RM, Rico-Lastres P, García G, Díaz JF, García P, Menéndez M. Structural and Functional Insights Into Skl and Pal Endolysins, Two Cysteine-Amidases With Anti-pneumococcal Activity. Dithiothreitol (DTT) Effect on Lytic Activity. Front Microbiol 2021; 12:740914. [PMID: 34777288 PMCID: PMC8586454 DOI: 10.3389/fmicb.2021.740914] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 09/16/2021] [Indexed: 01/21/2023] Open
Abstract
We have structurally and functionally characterized Skl and Pal endolysins, the latter being the first endolysin shown to kill effectively Streptococcus pneumoniae, a leading cause of deathly diseases. We have proved that Skl and Pal are cysteine-amidases whose catalytic domains, from CHAP and Amidase_5 families, respectively, share an α3β6-fold with papain-like topology. Catalytic triads are identified (for the first time in Amidase_5 family), and residues relevant for substrate binding and catalysis inferred from in silico models, including a calcium-binding site accounting for Skl dependence on this cation for activity. Both endolysins contain a choline-binding domain (CBD) with a β-solenoid fold (homology modeled) and six conserved choline-binding loci whose saturation induced dimerization. Remarkably, Pal and Skl dimers display a common overall architecture, preserved in choline-bound dimers of pneumococcal lysins with other catalytic domains and bond specificities, as disclosed using small angle X-ray scattering (SAXS). Additionally, Skl is proved to be an efficient anti-pneumococcal agent that kills multi-resistant strains and clinical emergent-serotype isolates. Interestingly, Skl and Pal time-courses of pneumococcal lysis were sigmoidal, which might denote a limited access of both endolysins to target bonds at first stages of lysis. Furthermore, their DTT-mediated activation, of relevance for other cysteine-peptidases, cannot be solely ascribed to reversal of catalytic-cysteine oxidation.
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Affiliation(s)
- Cristina Gallego-Páramo
- Instituto de Química-Física Rocasolano, Consejo Superior de Investigaciones Científicas, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Noelia Hernández-Ortiz
- Instituto de Química-Física Rocasolano, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Rubén M Buey
- Metabolic Engineering Group, Universidad de Salamanca, Salamanca, Spain
| | - Palma Rico-Lastres
- Instituto de Química-Física Rocasolano, Consejo Superior de Investigaciones Científicas, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Guadalupe García
- Instituto de Química-Física Rocasolano, Consejo Superior de Investigaciones Científicas, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - J Fernando Díaz
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Pedro García
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III (ISCIII), Madrid, Spain.,Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Margarita Menéndez
- Instituto de Química-Física Rocasolano, Consejo Superior de Investigaciones Científicas, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
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8
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Ho MKY, Zhang P, Chen X, Xia J, Leung SSY. Bacteriophage endolysins against gram-positive bacteria, an overview on the clinical development and recent advances on the delivery and formulation strategies. Crit Rev Microbiol 2021; 48:303-326. [PMID: 34478359 DOI: 10.1080/1040841x.2021.1962803] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Facing the increasing threat of multi-drug antimicrobial resistance (AMR), humans strive to search for antibiotic drug candidates and antibacterial alternatives from all possible places, from soils in remote areas to deep in the sea. In this "gold rush for antibacterials," researchers turn to the natural enemy of bacterial cells, bacteriophage (phages), and find them a rich source of weapons for AMR bacteria. Endolysins (lysins), the enzymes phages use to break the bacterial cells from within, have been shown to be highly selective and efficient in killing their target bacteria from outside while maintaining a low occurrence of bacterial resistance. In this review, we start with the structures and mechanisms of action of lysins against Gram-positive (GM+) bacteria. The developmental history of lysins is also outlined. Then, we detail the latest preclinical and clinical research on their safety and efficacy against GM+ bacteria, focusing on the formulation strategies of these enzymes. Finally, the challenges and potential hurdles are discussed. Notwithstanding these limitations, the trends in development indicate that the first, approved lysin drugs will be available soon in the near future. Overall, this review presents a timely summary of the current progress on lysins as antibacterial enzymes for AMR GM+ bacteria, and provides a guidebook for biomaterial researchers who are dedicating themselves to the battle against bacterial infections.
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Affiliation(s)
- Marco Kai Yuen Ho
- School of Pharmacy, The Chinese University of Hong Kong, Hong Kong, China
| | - Pengfei Zhang
- School of Pharmacy, The Chinese University of Hong Kong, Hong Kong, China
| | - Xi Chen
- Department of Chemistry, The Chinese University of Hong Kong, Hong Kong, China
| | - Jiang Xia
- Department of Chemistry, The Chinese University of Hong Kong, Hong Kong, China
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9
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Furlon JM, Mitchell SJ, Bailey-Kellogg C, Griswold KE. Bioinformatics-driven discovery of novel Clostridioides difficile lysins and experimental comparison with highly active benchmarks. Biotechnol Bioeng 2021; 118:2482-2492. [PMID: 33748952 PMCID: PMC10049856 DOI: 10.1002/bit.27759] [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: 12/31/2020] [Revised: 03/07/2021] [Accepted: 03/13/2021] [Indexed: 11/11/2022]
Abstract
Clostridioides difficile is the single most deadly bacterial pathogen in the United States, and its global prevalence and outsized health impacts underscore the need for more effective therapeutic options. Towards this goal, a novel group of modified peptidoglycan hydrolases with significant in vitro bactericidal activity have emerged as potential candidates for treating C. difficile infections (CDI). To date, discovery and development efforts directed at these CDI-specific lysins have been limited, and in particular there has been no systematic comparison of known or newly discovered lysin candidates. Here, we detail bioinformatics-driven discovery of six new anti-C. difficile lysins belonging to the amidase-3 family of enzymes, and we describe experimental comparison of their respective catalytic domains (CATs) with highly active CATs from the literature. Our quantitative analyses include metrics for expression level, inherent antibacterial activity, breadth of strain selectivity, killing of germinating spores, and structural and functional measures of thermal stability. Importantly, prior studies have not examined stability as a performance metric, and our results show that the panel of eight enzymes possess widely variable thermal denaturation temperatures and resistance to heat inactivation, including some enzymes that exhibit marginal stability at body temperature. Ultimately, no single enzyme dominated with respect to all performance measures, suggesting the need for a balanced assessment of lysin properties during efforts to find, engineer, and develop candidates with true clinical potential.
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Affiliation(s)
- Jacob M Furlon
- Thayer School of Engineering, Dartmouth, Hanover, New Hampshire, USA
| | | | - Chris Bailey-Kellogg
- Department of Computer Science, Dartmouth, Hanover, New Hampshire, USA.,Lyticon LLC, Lebanon, New Hampshire, USA
| | - Karl E Griswold
- Thayer School of Engineering, Dartmouth, Hanover, New Hampshire, USA.,Lyticon LLC, Lebanon, New Hampshire, USA
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10
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van der Kamp I, Draper LA, Smith MK, Buttimer C, Ross RP, Hill C. A New Phage Lysin Isolated from the Oral Microbiome Targeting Streptococcus pneumoniae. Pharmaceuticals (Basel) 2020; 13:ph13120478. [PMID: 33352708 PMCID: PMC7767030 DOI: 10.3390/ph13120478] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 12/15/2020] [Accepted: 12/17/2020] [Indexed: 12/22/2022] Open
Abstract
Streptococcus pneumoniae is highly pathogenic and causes several mucosal and invasive infections. Due to the rising number of multidrug-resistant (MDR) strains of S. pneumoniae, new antimicrobials with alternative mechanisms of action are urgently needed. In this study, we identified two new Streptococcal phages from the oral microbiome, 23TH and SA01. Their lysins, 23TH_48 and SA01_53, were recombinantly expressed, characterized and tested for their lethality. SA01_53 was found to only lyse its host strain of S. anginosus, while 23TH_48 was found to possess a broader lytic activity beyond its host strain of S. infantis, with several S. pneumoniae isolates sensitive to its lytic activity. 23TH_48 at a concentration of five activity units per mL (U/mL) was found to reduce cell counts of S. pneumoniae DSM 24048 by 4 log10 colony forming units per mL (CFU/mL) within 1 h and effectively prevented and destroyed biofilms of S. pneumoniae R6 at concentrations of 228.8 ng/µL and 14.3 ng/µL, respectively. Given its high lytic activity, 23TH_48 could prove to be a promising candidate to help combat pneumococcal infections.
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Affiliation(s)
- Imme van der Kamp
- APC Microbiome Ireland, University College Cork, T12 YT20 Cork, Ireland; (I.v.d.K.); (L.A.D.); (M.K.S.); (C.B.); (R.P.R.)
| | - Lorraine A. Draper
- APC Microbiome Ireland, University College Cork, T12 YT20 Cork, Ireland; (I.v.d.K.); (L.A.D.); (M.K.S.); (C.B.); (R.P.R.)
| | - Muireann K. Smith
- APC Microbiome Ireland, University College Cork, T12 YT20 Cork, Ireland; (I.v.d.K.); (L.A.D.); (M.K.S.); (C.B.); (R.P.R.)
| | - Colin Buttimer
- APC Microbiome Ireland, University College Cork, T12 YT20 Cork, Ireland; (I.v.d.K.); (L.A.D.); (M.K.S.); (C.B.); (R.P.R.)
| | - R. Paul Ross
- APC Microbiome Ireland, University College Cork, T12 YT20 Cork, Ireland; (I.v.d.K.); (L.A.D.); (M.K.S.); (C.B.); (R.P.R.)
| | - Colin Hill
- APC Microbiome Ireland, University College Cork, T12 YT20 Cork, Ireland; (I.v.d.K.); (L.A.D.); (M.K.S.); (C.B.); (R.P.R.)
- School of Microbiology, University College Cork, T12 YN60 Cork, Ireland
- Correspondence:
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11
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Design, Overproduction and Purification of the Chimeric Phage Lysin MLTphg Fighting against Staphylococcus aureus. Processes (Basel) 2020. [DOI: 10.3390/pr8121587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
With the increasing spread of multidrug-resistant bacterial pathogens, it is of great importance to develop alternatives to conventional antibiotics. Here, we report the generation of a chimeric phage lysin, MLTphg, which was assembled by joining the lysins derived from Meiothermus bacteriophage MMP7 and Thermus bacteriophage TSP4 with a flexible linker via chimeolysin engineering. As a potential antimicrobial agent, MLTphg can be obtained by overproduction in Escherichia coli BL21(DE3) cells and the following Ni-affinity chromatography. Finally, we recovered about 40 ± 1.9 mg of MLTphg from 1 L of the host E. coli BL21(DE3) culture. The purified MLTphg showed peak activity against Staphylococcus aureus ATCC6538 between 35 and 40 °C, and maintained approximately 44.5 ± 2.1% activity at room temperature (25 °C). Moreover, as a produced chimera, it exhibited considerably improved bactericidal activity against Staphylococcus aureus (2.9 ± 0.1 log10 reduction was observed upon 40 nM MLTphg treatment at 37 °C for 30 min) and also a group of antibiotic-resistant bacteria compared to its parental lysins, TSPphg and MMPphg. In the current age of growing antibiotic resistance, our results provide an engineering basis for developing phage lysins as novel antimicrobial agents and shed light on bacteriophage-based strategies to tackle bacterial infections.
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12
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A Choline-Recognizing Monomeric Lysin, ClyJ-3m, Shows Elevated Activity against Streptococcus pneumoniae. Antimicrob Agents Chemother 2020; 64:AAC.00311-20. [PMID: 32958710 DOI: 10.1128/aac.00311-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 09/10/2020] [Indexed: 12/29/2022] Open
Abstract
Streptococcus pneumoniae is a leading pathogen for bacterial pneumonia, which can be treated with bacteriophage lysins harboring a conserved choline binding module (CBM). Such lysins regularly function as choline-recognizing dimers. Previously, we reported a pneumococcus-specific lysin ClyJ comprising the binding domain from the putative endolysin gp20 from the Streptococcus phage SPSL1 and the CHAP (cysteine, histidine-dependent amidohydrolase/peptidase) catalytic domain from the PlyC lysin. A variant of ClyJ with a shortened linker, i.e., ClyJ-3, shows improved activity and reduced cytotoxicity. Resembling typical CBM-containing lysins, ClyJ-3 dimerized upon binding with choline. Herein, we further report a choline-recognizing variant of ClyJ-3, i.e., ClyJ-3m, constructed by deleting its C-terminal tail. Biochemical characterization showed that ClyJ-3m remains a monomer after it binds to choline yet exhibits improved bactericidal activity against multiple pneumococcal strains with different serotypes. In an S. pneumoniae-infected bacteremia model, a single intraperitoneal administration of 2.32 μg/mouse of ClyJ-3m showed 70% protection, while only 20% of mice survived in the group receiving an equal dose of ClyJ-3 (P < 0.05). A pharmacokinetic analysis following single intravenously doses of 0.29 and 1.16 mg/kg of ClyJ-3 or ClyJ-3m in BALB/c mice revealed that ClyJ-3m shows a similar half-life but less clearance and a greater area under curve than ClyJ-3. Taken together, the choline-recognizing monomer ClyJ-3m exhibited enhanced bactericidal activity and improved pharmacokinetic proprieties compared to those of its parental ClyJ-3 lysin. Our study also provides a new way for rational design and programmed engineering of lysins targeting S. pneumoniae.
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Silva MD, Oliveira H, Faustino A, Sillankorva S. Characterization of MSlys, the endolysin of Streptococcus pneumoniae phage MS1. ACTA ACUST UNITED AC 2020; 28:e00547. [PMID: 33204659 PMCID: PMC7648177 DOI: 10.1016/j.btre.2020.e00547] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 10/23/2020] [Accepted: 10/23/2020] [Indexed: 01/21/2023]
Abstract
MSlys is a choline binding protein from pneumococcal MS1 phage. Planktonic and biofilm S. pneumoniae cells are affected by MSlys treatment. MSlys is active against isolates from otitis media infections and works in the conditions commonly found in this environment.
Despite the use of pneumococcal conjugate vaccines, the number of infections related to Streptococcus pneumoniae continues to be alarming. Herein, we identified, characterized the MSlys endolysin encoded in the phage MS1. We further tested its antimicrobial efficacy against planktonic and biofilm cells, assessing the culturability of cells and biofilm structure by scanning electron microscopy, and confocal laser scanning microscopy. The modular MSlys endolysin consists of an amidase catalytic domain and a choline-binding domain. MSlys is active against isolates of children with otitis media, and conditions close to those found in the middle ear. Treatment with MSlys (2 h, 4 μM) reduced planktonic cultures by 3.5 log10 CFU/mL, and 24- and 48-h-old biofilms by 1.5 and 1.8 log10 CFU/mL, respectively. Imaging of the biofilms showed thinner and damaged structures compared to control samples. The recombinantly expressed MSlys may be a suitable candidate for treating pneumococcal infections, including otitis media.
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Affiliation(s)
- Maria Daniela Silva
- CEB - Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057 Braga, Portugal
| | - Hugo Oliveira
- CEB - Centre of Biological Engineering, LIBRO - Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, 4710-057 Braga, Portugal
| | - Alberta Faustino
- Clinical Pathology Department, Hospital de Braga, 4710-243 Braga, Portugal
| | - Sanna Sillankorva
- INL - International Iberian Nanotechnology Laboratory, Avenida Mestre José Veiga, 4715-330 Braga, Portugal
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Ding Y, Zhang Y, Huang C, Wang J, Wang X. An Endolysin LysSE24 by Bacteriophage LPSE1 Confers Specific Bactericidal Activity against Multidrug-Resistant Salmonella Strains. Microorganisms 2020; 8:E737. [PMID: 32429030 PMCID: PMC7284969 DOI: 10.3390/microorganisms8050737] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 05/04/2020] [Accepted: 05/13/2020] [Indexed: 12/16/2022] Open
Abstract
Salmonella is responsible for a wide range of infections and is a constant threat to public health, particularly in light of emerging antibiotic resistance. The use of bacteriophages and phage endolysins as specific antibacterial agents is a promising strategy to control this bacterial infection. Endolysins are important proteins during the process of bacteria lysis by bacteriophages. In this study, we identify a novel endolysin, named LysSE24. LysSE24 was predicted to possess N-acetylmuramidases activity, with a molecular mass of ca. 17.4 kDa and pI 9.44. His-tagged LysSE24 was heterologously expressed and purified by Ni-NTA chromatography. LysSE24 exhibited optimal bactericidal activity against Salmonella Enteritidis ATCC 13076 at a concentration of 0.1 μM. Salmonella population (measured by OD600 nm) decreased significantly (p < 0.05) after 10 min of incubation in combination with the outer membrane permeabilizer in vitro. It also showed antibacterial activity against a panel of 23 tested multidrug-resistant Salmonella strains. Bactericidal activity of LysSE24 was evaluated in terms of pH, temperature, and ionic strength. It was very stable with different pH (4.0 to 10.0) at different temperatures (20 to 60 °C). Both K+ and Na+ at concentrations between 0.1 to 100 mM showed no effects on its bactericidal activity, while a high concentration of Ca2+ and Mg2+ showed efficacy. Transmission electron microscopy revealed that exposure to 0.1 μM LysSE24 for up to 5 min caused a remarkable modification of the cell shape of Salmonella Enteritidis ATCC 13076. These results indicate that recombinant LysSE24 represents a promising antimicrobial activity against Salmonella, especially several multidrug-resistant Salmonella strains. Further studies can be developed to improve its bactericidal activity without the need for pretreatment with outer membrane-destabilizing agents by synthetic biology methods.
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Affiliation(s)
- Yifeng Ding
- Key Laboratory of Environment Correlative Dietology, Huazhong Agricultural University, Wuhan 430070, China; (Y.D.); (J.W.)
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (Y.Z.); (C.H.)
| | - Yu Zhang
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (Y.Z.); (C.H.)
| | - Chenxi Huang
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (Y.Z.); (C.H.)
| | - Jia Wang
- Key Laboratory of Environment Correlative Dietology, Huazhong Agricultural University, Wuhan 430070, China; (Y.D.); (J.W.)
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (Y.Z.); (C.H.)
| | - Xiaohong Wang
- Key Laboratory of Environment Correlative Dietology, Huazhong Agricultural University, Wuhan 430070, China; (Y.D.); (J.W.)
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (Y.Z.); (C.H.)
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Gutiérrez D, Garrido V, Fernández L, Portilla S, Rodríguez A, Grilló MJ, García P. Phage Lytic Protein LysRODI Prevents Staphylococcal Mastitis in Mice. Front Microbiol 2020; 11:7. [PMID: 32038593 PMCID: PMC6989612 DOI: 10.3389/fmicb.2020.00007] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 01/06/2020] [Indexed: 12/29/2022] Open
Abstract
Phage lytic proteins are promising antimicrobials that could complement conventional antibiotics and help to combat multi-drug resistant bacteria that cause important human and animal infections. Here, we report the characterization of endolysin LysRODI (encoded by staphylophage phiIPLA-RODI) and its application as a prophylactic mastitis treatment. The main properties of LysRODI were compared with those of endolysin LysA72 (encoded by staphylophage phiIPLA35) and the chimeric protein CHAPSH3b (derived from the virion-associated peptidoglycan hydrolase HydH5 and lysostaphin). Time-kill experiments performed with Staphylococcus aureus and Staphylococcus epidermidis demonstrated that the killing rate of LysRODI and CHAPSH3b is higher than that of LysA72 (0.1 μM protein removed 107 CFU/ml of S. aureus in 30 min). Of note, all proteins failed to select resistant mutants as bacterial exposure to sub-lethal concentrations of the proteins did not alter the MIC values. Additionally, LysRODI and CHAPSH3b were non-toxic in a zebrafish embryo model at concentrations near the MIC (0.5 and 0.7 μM, respectively). Moreover, these two proteins significantly reduced mortality in a zebrafish model of systemic infection. In contrast to LysRODI, the efficacy of CHAPSH3b was dose-dependent in zebrafish, requiring higher-dose treatments to achieve the maximum survival rate. For this reason, LysRODI was selected for further analysis in mice, demonstrating great efficacy to prevent mammary infections by S. aureus and S. epidermidis. Our findings strongly support the use of phage lytic proteins as a new strategy to prevent staphylococcal mastitis.
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Affiliation(s)
- Diana Gutiérrez
- DairySafe Group, Departamento de Tecnología y Biotecnología de Productos Lácteos, Instituto de Productos Lácteos de Asturias (IPLA-CSIC), Villaviciosa, Spain
| | - Victoria Garrido
- Departamento de Sanidad Animal, Instituto de Agrobiotecnología, CSIC-Gobierno de Navarra, Mutilva, Spain
| | - Lucía Fernández
- DairySafe Group, Departamento de Tecnología y Biotecnología de Productos Lácteos, Instituto de Productos Lácteos de Asturias (IPLA-CSIC), Villaviciosa, Spain
| | - Silvia Portilla
- DairySafe Group, Departamento de Tecnología y Biotecnología de Productos Lácteos, Instituto de Productos Lácteos de Asturias (IPLA-CSIC), Villaviciosa, Spain
| | - Ana Rodríguez
- DairySafe Group, Departamento de Tecnología y Biotecnología de Productos Lácteos, Instituto de Productos Lácteos de Asturias (IPLA-CSIC), Villaviciosa, Spain
| | - María Jesús Grilló
- Departamento de Sanidad Animal, Instituto de Agrobiotecnología, CSIC-Gobierno de Navarra, Mutilva, Spain
| | - Pilar García
- DairySafe Group, Departamento de Tecnología y Biotecnología de Productos Lácteos, Instituto de Productos Lácteos de Asturias (IPLA-CSIC), Villaviciosa, Spain
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Caflisch KM, Suh GA, Patel R. Biological challenges of phage therapy and proposed solutions: a literature review. Expert Rev Anti Infect Ther 2019; 17:1011-1041. [PMID: 31735090 DOI: 10.1080/14787210.2019.1694905] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Introduction: In light of the emergence of antibiotic-resistant bacteria, phage (bacteriophage) therapy has been recognized as a potential alternative or addition to antibiotics in Western medicine for use in humans.Areas covered: This review assessed the scientific literature on phage therapy published between 1 January 2007 and 21 October 2019, with a focus on the successes and challenges of this prospective therapeutic.Expert opinion: Efficacy has been shown in animal models and experimental findings suggest promise for the safety of human phagotherapy. Significant challenges remain to be addressed prior to the standardization of phage therapy in the West, including the development of phage-resistant bacteria; the pharmacokinetic complexities of phage; and any potential human immune response incited by phagotherapy.
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Affiliation(s)
- Katherine M Caflisch
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, USA
| | - Gina A Suh
- Division of Infectious Diseases, Department of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Robin Patel
- Division of Infectious Diseases, Department of Medicine, Mayo Clinic, Rochester, MN, USA.,Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
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Gondil VS, Harjai K, Chhibber S. Endolysins as emerging alternative therapeutic agents to counter drug-resistant infections. Int J Antimicrob Agents 2019; 55:105844. [PMID: 31715257 DOI: 10.1016/j.ijantimicag.2019.11.001] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 08/02/2019] [Accepted: 11/05/2019] [Indexed: 12/19/2022]
Abstract
Endolysins are the lytic products of bacteriophages which play a specific role in the release of phage progeny by degrading the peptidoglycan of the host bacterium. In the light of antibiotic resistance, endolysins are being considered as alternative therapeutic agents because of their exceptional ability to target bacterial cells when applied externally. Endolysins have been studied against a number of drug-resistant pathogens to assess their therapeutic ability. This review focuses on the structure of endolysins in terms of cell binding and catalytic domains, lytic ability, resistance, safety, immunogenicity and future applications. It primarily reviews recent advancements made in evaluation of the therapeutic potential of endolysins, including their origin, host range, applications, and synergy with conventional and non-conventional antimicrobial agents.
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Affiliation(s)
- Vijay Singh Gondil
- Department of Microbiology, Basic Medical Sciences, Panjab University, Chandigarh, India
| | - Kusum Harjai
- Department of Microbiology, Basic Medical Sciences, Panjab University, Chandigarh, India
| | - Sanjay Chhibber
- Department of Microbiology, Basic Medical Sciences, Panjab University, Chandigarh, India.
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Bacteriophage φEf11 ORF28 Endolysin, a Multifunctional Lytic Enzyme with Properties Distinct from All Other Identified Enterococcus faecalis Phage Endolysins. Appl Environ Microbiol 2019; 85:AEM.00555-19. [PMID: 30979842 DOI: 10.1128/aem.00555-19] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 04/09/2019] [Indexed: 02/01/2023] Open
Abstract
ϕEf11 is a temperate Siphoviridae bacteriophage that infects strains of Enterococcus faecalis The ϕEf11 genome, encompassing 65 open reading frames (ORFs), is contained within 42,822 bp of DNA. Within this genome, a module of six lysis-related genes was identified. Based upon sequence homology, one of these six genes, ORF28, was predicted to code for an N-acetylmuramoyl-l-alanine amidase endolysin of 46.133 kDa, composed of 421 amino acids. The PCR-amplified ORF28 was cloned and expressed, and the resulting gene product was affinity purified to homogeneity. The purified protein was obtained from a fusion protein that exhibited a molecular mass of 72.5 kDa, consistent with a 46.1-kDa protein combined with a fused 26.5-kDa glutathione S-transferase tag. It produced rapid, profound lysis in E. faecalis populations and was active against 73 of 103 (71%) E. faecalis strains tested. In addition, it caused substantial destruction of E. faecalis biofilms. The lysin was quite stable, retaining its activity for three years in refrigerated storage, was stable over a wide range of pHs, and was unaffected by the presence of a reducing agent; however, it was inhibited by increasing concentrations of Ca2+ Liquid chromatography-mass spectrometry analysis of E. faecalis cell wall digestion products produced by the ORF28 endolysin indicated that the lysin acted as an N-acetylmuramidase, an endo-β-N-acetylglucosaminidase, and an endopeptidase, rather than an N-acetylmuramoyl-l-alanine amidase. The ϕEf11 ORF28 lysin shared 10% to 37% amino acid identity with the lytic enzymes of all other characterized E. faecalis bacteriophages.IMPORTANCE The emergence of multidrug-resistant pathogenic microorganisms has brought increasing attention to the urgent need for the development of alternative antimicrobial strategies. One such alternative to conventional antibiotics employs lytic enzymes (endolysins) that are produced by bacteriophages in the course of lytic infection. During lytic infection by a bacteriophage, these enzymes hydrolyze the cell wall peptidoglycan, resulting in the lysis of the host cell. However, external endolysin application can result in lysis from without. In this study, we have cloned, expressed, purified, and characterized an endolysin produced by a bacteriophage infecting strains of Enterococcus faecalis The lysin is broadly active against most of the tested E. faecalis strains and exhibits multifunctional enzymatic specificities that differ from all other characterized endolysins produced by E. faecalis bacteriophages.
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19
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Vázquez R, García P. Synergy Between Two Chimeric Lysins to Kill Streptococcus pneumoniae. Front Microbiol 2019; 10:1251. [PMID: 31231338 PMCID: PMC6560164 DOI: 10.3389/fmicb.2019.01251] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 05/20/2019] [Indexed: 01/02/2023] Open
Abstract
Phage lysins constitute a new generation of antimicrobials that are becoming a promising alternative and complementation to current antibiotic therapies, which are nowadays called into question by the increasing numbers of multiresistant bacteria. Streptococcus pneumoniae is a leading human pathogen causing serious infectious diseases in children and adults. Within the host-parasite interplay system of pneumococcus and its phages, several antipneumococcal lysins have been described and, among them, chimeric lysins Cpl-711 and PL3 stand out for their potent bactericidal activities. Here, evidence is presented on the synergistic cooperation of the catalytically diverse lysins Cpl-711 and PL3 in different assays, like purified cell wall enzymatic degradation, in vitro bacterial cell growth inhibition, and killing of both planktonic and biofilm grown cells. Synergy between Cpl-711 and PL3 has been shown to reduce the amount of enzyme necessary to inhibit growth in checkerboard assays with a sum of fractional inhibitory concentrations ≤0.5 for all pneumococcal strains tested, while also significatively increasing bactericidal effect by ≥2 logs with respect to the sum of activities of Cpl-711 and PL3 individual treatments. Moreover, the combination of these two lysins showed synergy in an adult zebrafish model of pneumococcal infection. This study consolidates the possibility of formulating highly efficient and synergistic antibacterial enzymes that could improve our ability to fight multiresistant bacterial infections.
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Affiliation(s)
- Roberto Vázquez
- Departamento de Biotecnología Microbiana y de Plantas, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain.,CIBER de Enfermedades Respiratorias, Madrid, Spain
| | - Pedro García
- Departamento de Biotecnología Microbiana y de Plantas, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain.,CIBER de Enfermedades Respiratorias, Madrid, Spain
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20
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Shang X, Nelson DC. Contributions of Net Charge on the PlyC Endolysin CHAP Domain. Antibiotics (Basel) 2019; 8:antibiotics8020070. [PMID: 31142020 PMCID: PMC6628322 DOI: 10.3390/antibiotics8020070] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 05/20/2019] [Accepted: 05/25/2019] [Indexed: 12/18/2022] Open
Abstract
Bacteriophage endolysins, enzymes that degrade the bacterial peptidoglycan (PG), have gained an increasing interest as alternative antimicrobial agents, due to their ability to kill antibiotic resistant pathogens efficiently when applied externally as purified proteins. Typical endolysins derived from bacteriophage that infect Gram-positive hosts consist of an N-terminal enzymatically-active domain (EAD) that cleaves covalent bonds in the PG, and a C-terminal cell-binding domain (CBD) that recognizes specific ligands on the surface of the PG. Although CBDs are usually essential for the EADs to access the PG substrate, some EADs possess activity in the absence of CBDs, and a few even display better activity profiles or an extended host spectrum than the full-length endolysin. A current hypothesis suggests a net positive charge on the EAD enables it to reach the negatively charged bacterial surface via ionic interactions in the absence of a CBD. Here, we used the PlyC CHAP domain as a model EAD to further test the hypothesis. We mutated negatively charged surface amino acids of the CHAP domain that are not involved in structured regions to neutral or positively charged amino acids in order to increase the net charge from -3 to a range from +1 to +7. The seven mutant candidates were successfully expressed and purified as soluble proteins. Contrary to the current hypothesis, none of the mutants were more active than wild-type CHAP. Analysis of electrostatic surface potential implies that the surface charge distribution may affect the activity of a positively charged EAD. Thus, we suggest that while charge should continue to be considered for future engineering efforts, it should not be the sole focus of such engineering efforts.
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Affiliation(s)
- Xiaoran Shang
- Institute for Bioscience and Biotechnology Research, Rockville, MD 20850, USA.
| | - Daniel C Nelson
- Institute for Bioscience and Biotechnology Research, Rockville, MD 20850, USA.
- Department of Veterinary Medicine, University of Maryland, College Park, MD 20742, USA.
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Validation and Stabilization of a Prophage Lysin of Clostridium perfringens by Using Yeast Surface Display and Coevolutionary Models. Appl Environ Microbiol 2019; 85:AEM.00054-19. [PMID: 30850429 DOI: 10.1128/aem.00054-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 02/27/2019] [Indexed: 01/15/2023] Open
Abstract
Bacteriophage lysins are compelling antimicrobial proteins whose biotechnological utility and evolvability would be aided by elevated stability. Lysin catalytic domains, which evolved as modular entities distinct from cell wall binding domains, can be classified into one of several families with highly conserved structure and function, many of which contain thousands of annotated homologous sequences. Motivated by the quality of these evolutionary data, the performance of generative protein models incorporating coevolutionary information was analyzed to predict the stability of variants in a collection of 9,749 multimutants across 10 libraries diversified at different regions of a putative lysin from a prophage region of a Clostridium perfringens genome. Protein stability was assessed via a yeast surface display assay with accompanying high-throughput sequencing. Statistical fitness of mutant sequences, derived from second-order Potts models inferred with different levels of sequence homolog information, was predictive of experimental stability with areas under the curve (AUCs) ranging from 0.78 to 0.85. To extract an experimentally derived model of stability, a logistic model with site-wise score contributions was regressed on the collection of multimutants. This achieved a cross-validated classification performance of 0.95. Using this experimentally derived model, 5 designs incorporating 5 or 6 mutations from multiple libraries were constructed. All designs retained enzymatic activity, with 4 of 5 increasing the melting temperature and with the highest-performing design achieving an improvement of +4°C.IMPORTANCE Bacteriophage lysins exhibit high specificity and activity toward host bacteria with which the phage coevolved. These properties of lysins make them attractive for use as antimicrobials. Although there has been significant effort to develop platforms for rapid lysin engineering, there have been numerous shortcomings when pursuing the ultrahigh throughput necessary for the discovery of rare combinations of mutations to improve performance. In addition to validation of a putative lysin and stabilization thereof, the experimental and computational methods presented here offer a new avenue for improving protein stability and are easily scalable to analysis of tens of millions of mutations in single experiments.
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ClyJ Is a Novel Pneumococcal Chimeric Lysin with a Cysteine- and Histidine-Dependent Amidohydrolase/Peptidase Catalytic Domain. Antimicrob Agents Chemother 2019; 63:AAC.02043-18. [PMID: 30642930 DOI: 10.1128/aac.02043-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 01/05/2019] [Indexed: 12/14/2022] Open
Abstract
Streptococcus pneumoniae is one of the leading pathogens that cause a variety of mucosal and invasive infections. With the increased emergence of multidrug-resistant S. pneumoniae, new antimicrobials with mechanisms of action different from conventional antibiotics are urgently needed. In this study, we identified a putative lysin (gp20) encoded by the Streptococcus phage SPSL1 using the LytA autolysin as a template. Molecular dissection of gp20 revealed a binding domain (GPB) containing choline-binding repeats (CBRs) that are high specificity for S. pneumoniae By fusing GPB to the CHAP (cysteine, histidine-dependent amidohydrolase/peptidase) catalytic domain of the PlyC lysin, we constructed a novel chimeric lysin, ClyJ, with improved activity to the pneumococcal Cpl-1 lysin. No resistance was observed in S. pneumoniae strains after exposure to incrementally doubling concentrations of ClyJ for 8 continuous days in vitro In a mouse bacteremia model using penicillin G as a control, a single intraperitoneal injection of ClyJ improved the survival rate of lethal S. pneumoniae-infected mice in a dose-dependent manner. Given its high lytic activity and safety profile, ClyJ may represent a promising alternative to combat pneumococcal infections.
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Wu M, Hu K, Xie Y, Liu Y, Mu D, Guo H, Zhang Z, Zhang Y, Chang D, Shi Y. A Novel Phage PD-6A3, and Its Endolysin Ply6A3, With Extended Lytic Activity Against Acinetobacter baumannii. Front Microbiol 2019; 9:3302. [PMID: 30687281 PMCID: PMC6333635 DOI: 10.3389/fmicb.2018.03302] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 12/18/2018] [Indexed: 01/21/2023] Open
Abstract
With widespread abuse of antibiotics, bacterial resistance has increasingly become a serious threat. Acinetobacter baumannii has emerged as one of the most important hospital-acquired pathogens worldwide. Bacteriophages (also called “phages”) could be used as a potential alternative therapy to meet the challenges posed by such pathogens. Endolysins from phages have also been attracting increasing interest as potential antimicrobial agents. Here, we isolated 14 phages against A. baumannii, determined the lytic spectrum of each phage, and selected one with a relatively broad host range, named vB_AbaP_PD-6A3 (PD-6A3 for short), for its biological characteristics. We over-expressed and purified the endolysin (Ply6A3) from this phage and tested its biological characteristics. The PD-6A3 is a novel phage, which can kill 32.4% (179/552) of clinical multidrug resistant A. baumannii (MDRAB) isolates. Interestingly, in vitro, this endolysin could not only inhibit A. baumannii, but also that of other strains, such as Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA). We found that lethal A. baumannii sepsis mice could be effectively rescued in vivo by phage PD-6A3 and endolysin Ply6A3 intraperitoneal injection. These characteristics reveal the promising potential of phage PD-6A3 and endolysin Ply6A3 as attractive candidates for the control of A. baumannii-associated nosocomial infections.
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Affiliation(s)
- Minle Wu
- Department of Clinical Laboratory, Pudong Hosipital Affiliated to Fudan University, Shanghai, China
| | - Kongying Hu
- Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Youhua Xie
- Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Yili Liu
- Department of Clinical Laboratory, Shanghai Public Health Clinical Center, Shanghai, China
| | - Di Mu
- Department of Clinical Laboratory, The Fourth People's Hospital of Shanghai, Shanghai, China
| | - Huimin Guo
- Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Zhifan Zhang
- Department of Clinical Laboratory, The Fourth People's Hospital of Shanghai, Shanghai, China
| | - Yingcong Zhang
- Department of Clinical Laboratory, Pudong Hosipital Affiliated to Fudan University, Shanghai, China
| | - Dong Chang
- Department of Clinical Laboratory, Pudong Hosipital Affiliated to Fudan University, Shanghai, China
| | - Yi Shi
- Department of Clinical Laboratory, The Fourth People's Hospital of Shanghai, Shanghai, China
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Vázquez R, García E, García P. Phage Lysins for Fighting Bacterial Respiratory Infections: A New Generation of Antimicrobials. Front Immunol 2018; 9:2252. [PMID: 30459750 PMCID: PMC6232686 DOI: 10.3389/fimmu.2018.02252] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 09/11/2018] [Indexed: 01/03/2023] Open
Abstract
Lower respiratory tract infections and tuberculosis are responsible for the death of about 4.5 million people each year and are the main causes of mortality in children under 5 years of age. Streptococcus pneumoniae is the most common bacterial pathogen associated with severe pneumonia, although other Gram-positive and Gram-negative bacteria are involved in respiratory infections as well. The ability of these pathogens to persist and produce infection under the appropriate conditions is also associated with their capacity to form biofilms in the respiratory mucous membranes. Adding to the difficulty of treating biofilm-forming bacteria with antibiotics, many of these strains are becoming multidrug resistant, and thus the alternative therapeutics available for combating this kind of infections are rapidly depleting. Given these concerns, it is urgent to consider other unconventional strategies and, in this regard, phage lysins represent an attractive resource to circumvent some of the current issues in infection treatment. When added exogenously, lysins break specific bonds of the peptidoglycan and have potent bactericidal effects against susceptible bacteria. These enzymes possess interesting features, including that they do not trigger an adverse immune response and raise of resistance is very unlikely. Although Gram-negative bacteria had been considered refractory to these compounds, strategies to overcome this drawback have been developed recently. In this review we describe the most relevant in vitro and in vivo results obtained to date with lysins against bacterial respiratory pathogens.
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Affiliation(s)
- Roberto Vázquez
- Centro de Investigaciones Biológicas (CSIC), Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Ernesto García
- Centro de Investigaciones Biológicas (CSIC), Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Pedro García
- Centro de Investigaciones Biológicas (CSIC), Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain
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Chemotherapy with Phage Lysins Reduces Pneumococcal Colonization of the Respiratory Tract. Antimicrob Agents Chemother 2018; 62:AAC.02212-17. [PMID: 29581113 DOI: 10.1128/aac.02212-17] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 03/17/2018] [Indexed: 01/21/2023] Open
Abstract
Bacteriophage-borne lytic enzymes, also named lysins or enzybiotics, are efficient agents for the killing of bacterial pathogens. The colonization of the respiratory tract by Streptococcus pneumoniae is a prerequisite for the establishment of the infection process. Hence, we have evaluated the antibacterial activities of three different lysins against pneumococcal colonization using human nasopharyngeal and lung epithelial cells as well as a mouse model of nasopharyngeal colonization. The lysins tested were the wild-type Cpl-1, the engineered Cpl-7S, and the chimera Cpl-711. Moreover, we included amoxicillin as a comparator antibiotic. Human epithelial cells were infected with three different multidrug-resistant clinical isolates of S. pneumoniae followed by a single dose of the corresponding lysin. The antimicrobial activities of these lysins were also evaluated using a mouse nasopharyngeal carriage model. The exposure of the infected epithelial cells to Cpl-7S did not result in the killing of any of the pneumococcal strains investigated. However, the treatment with Cpl-1 or Cpl-711 increased the killing of S. pneumoniae organisms adhered to both types of human epithelial cells, with Cpl-711 being more effective than Cpl-1, at subinhibitory concentrations. In addition, a treatment with amoxicillin had no effect on reducing the carrier state, whereas mice treated by the intranasal route with Cpl-711 showed significantly reduced nasopharyngeal colonization, with no detection of bacterial load in 20 to 40% of the mice. This study indicates that Cpl-1 and Cpl-711 lysins might be promising antimicrobial candidates for therapy against pneumococcal colonization.
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Fernández-Ruiz I, Coutinho FH, Rodriguez-Valera F. Thousands of Novel Endolysins Discovered in Uncultured Phage Genomes. Front Microbiol 2018; 9:1033. [PMID: 29867909 PMCID: PMC5968864 DOI: 10.3389/fmicb.2018.01033] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 05/01/2018] [Indexed: 12/05/2022] Open
Abstract
Bacteriophages express endolysins toward the end of their replication cycle to degrade the microbial cell wall from within, allowing viral progeny to be released. Endolysins can also degrade the prokaryotic cell wall from the outside, thus have potential to be used for biotechnological and medical purposes. Multiple endolysins have been identified within the genomes of isolated phages, but their diversity in uncultured phages has been overlooked. We used a bioinformatics pipeline to identify novel endolysins from nearly 200,000 uncultured viruses. We report the discovery of 2,628 putative endolysins, many of which displayed novel domain architectures. In addition, several of the identified proteins are predicted to be active against genera that include pathogenic bacteria. These discoveries enhance the diversity of known endolysins and are a stepping stone for developing medical and biotechnological applications that rely on bacteriophages, the most diverse biological entities on Earth.
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Affiliation(s)
- Iris Fernández-Ruiz
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández de Elche, San Juan de Alicante, Spain
| | - Felipe H Coutinho
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández de Elche, San Juan de Alicante, Spain
| | - Francisco Rodriguez-Valera
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández de Elche, San Juan de Alicante, Spain
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Gerstmans H, Criel B, Briers Y. Synthetic biology of modular endolysins. Biotechnol Adv 2018; 36:624-640. [DOI: 10.1016/j.biotechadv.2017.12.009] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/08/2017] [Accepted: 12/13/2017] [Indexed: 01/15/2023]
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Engineering of Phage-Derived Lytic Enzymes: Improving Their Potential as Antimicrobials. Antibiotics (Basel) 2018; 7:antibiotics7020029. [PMID: 29565804 PMCID: PMC6023083 DOI: 10.3390/antibiotics7020029] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 03/16/2018] [Accepted: 03/20/2018] [Indexed: 12/31/2022] Open
Abstract
Lytic enzymes encoded by bacteriophages have been intensively explored as alternative agents for combating bacterial pathogens in different contexts. The antibacterial character of these enzymes (enzybiotics) results from their degrading activity towards peptidoglycan, an essential component of the bacterial cell wall. In fact, phage lytic products have the capacity to kill target bacteria when added exogenously in the form of recombinant proteins. However, there is also growing recognition that the natural bactericidal activity of these agents can, and sometimes needs to be, substantially improved through manipulation of their functional domains or by equipping them with new functions. In addition, often, native lytic proteins exhibit features that restrict their applicability as effective antibacterials, such as poor solubility or reduced stability. Here, I present an overview of the engineering approaches that can be followed not only to overcome these and other restrictions, but also to generate completely new antibacterial agents with significantly enhanced characteristics. As conventional antibiotics are running short, the remarkable progress in this field opens up the possibility of tailoring efficient enzybiotics to tackle the most menacing bacterial infections.
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Csl2, a novel chimeric bacteriophage lysin to fight infections caused by Streptococcus suis, an emerging zoonotic pathogen. Sci Rep 2017; 7:16506. [PMID: 29184097 PMCID: PMC5705598 DOI: 10.1038/s41598-017-16736-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 11/16/2017] [Indexed: 12/20/2022] Open
Abstract
Streptococcus suis is a Gram-positive bacterium that infects humans and various animals, causing human mortality rates ranging from 5 to 20%, as well as important losses for the swine industry. In addition, there is no effective vaccine for S. suis and isolates with increasing antibiotic multiresistance are emerging worldwide. Facing this situation, wild type or engineered bacteriophage lysins constitute a promising alternative to conventional antibiotics. In this study, we have constructed a new chimeric lysin, Csl2, by fusing the catalytic domain of Cpl-7 lysozyme to the CW_7 repeats of LySMP lysin from an S. suis phage. Csl2 efficiently kills different S. suis strains and shows noticeable activity against a few streptococci of the mitis group. Specifically, 15 µg/ml Csl2 killed 4.3 logs of S. suis serotype 2 S735 strain in 60 min, in a buffer containing 150 mM NaCl and 10 mM CaCl2, at pH 6.0. We have set up a protocol to form a good biofilm with the non-encapsulated S. suis mutant strain BD101, and the use of 30 µg/ml Csl2 was enough for dispersing such biofilms and reducing 1–2 logs the number of planktonic bacteria. In vitro results have been validated in an adult zebrafish model of infection.
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