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Li X, Zhang B, Tong X, Zhou T, Li M, Barkema HW, Nobrega DB, Kastelic JP, Xu C, Han B, Gao J. Biological and genomic characterization of 4 novel bacteriophages isolated from sewage or the environment using non-aureus Staphylococci strains. Vet Microbiol 2024; 294:110133. [PMID: 38820726 DOI: 10.1016/j.vetmic.2024.110133] [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: 02/27/2024] [Revised: 05/14/2024] [Accepted: 05/27/2024] [Indexed: 06/02/2024]
Abstract
Non-aureus staphylococci (NAS) are an essential group of bacteria causing antimicrobial resistant intramammary infections in livestock, particularly dairy cows. Therefore, bacteriophages emerge as a potent bactericidal agent for NAS mastitis. This study aimed to obtain NAS-specific bacteriophages using bacterial strains isolated from cows with mastitis, subsequently evaluating their morphological, genomic, and lytic characteristics. Four distinct NAS bacteriophages were recovered from sewage or the environment of Chinese dairy farms; PT1-1, PT94, and PT1-9 were isolated using Staphylococcus chromogenes and PT1-4 using Staphylococcus gallinarum. Both PT1-1 (24/54, 44 %) and PT94 (28/54, 52 %) had broader lysis than PT1-4 (3/54, 6 %) and PT1-9 (10/54, 19 %), but PT1-4 and PT1-9 achieved cross-species lysis. All bacteriophages had a short latency period and good environmental tolerance, including surviving at pH=4-10 and at 30-60℃. Except for PT1-9, all bacteriophages had excellent bactericidal efficacy within 5 h of co-culture with host bacteria in vitro at various multiplicity of infection (MOIs). Based on whole genome sequencing, average nucleotide identity (ANI) analysis of PT1-1 and PT94 can be classified as the same species, consistent with whole-genome synteny analysis. Although motifs shared by the 4 bacteriophages differed little from those of other bacteriophages, a phylogenetic tree based on functional proteins indicated their novelty. Moreover, based on whole genome comparisons, we inferred that cross-species lysis of bacteriophage may be related to the presence of "phage tail fiber." In conclusion 4 novel NAS bacteriophages were isolated; they had good biological properties and unique genomes, with potential for NAS mastitis therapy.
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Affiliation(s)
- Xiaoping Li
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Yuanmingyuan West Road, Beijing 100193, China
| | - Baoling Zhang
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Yuanmingyuan West Road, Beijing 100193, China
| | - Xiaofang Tong
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Yuanmingyuan West Road, Beijing 100193, China
| | - Tao Zhou
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, Huimin Road, Chengdu 611130, China
| | - Moli Li
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Yuanmingyuan West Road, Beijing 100193, China
| | - Herman W Barkema
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Diego B Nobrega
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - John P Kastelic
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Chuang Xu
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Yuanmingyuan West Road, Beijing 100193, China
| | - Bo Han
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Yuanmingyuan West Road, Beijing 100193, China
| | - Jian Gao
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Yuanmingyuan West Road, Beijing 100193, China.
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Kulshrestha M, Tiwari M, Tiwari V. Bacteriophage therapy against ESKAPE bacterial pathogens: Current status, strategies, challenges, and future scope. Microb Pathog 2024; 186:106467. [PMID: 38036110 DOI: 10.1016/j.micpath.2023.106467] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/19/2023] [Accepted: 11/24/2023] [Indexed: 12/02/2023]
Abstract
The ESKAPE pathogens are the primary threat due to their constant spread of drug resistance worldwide. These pathogens are also regarded as opportunistic pathogens and could potentially cause nosocomial infections. Most of the ESKAPE pathogens have developed resistance to almost all the antibiotics that are used against them. Therefore, to deal with antimicrobial resistance, there is an urgent requirement for alternative non-antibiotic strategies to combat this rising issue of drug-resistant organisms. One of the promising alternatives to this scenario is implementing bacteriophage therapy. This under-explored mode of treatment in modern medicine has posed several concerns, such as preferable phages for the treatment, impact on the microbiome (or gut microflora), dose optimisation, safety, etc. The review will cover a rationale for phage therapy, clinical challenges, and propose phage therapy as an effective therapeutic against bacterial coinfections during pandemics. This review also addresses the expected uncertainties for administering the phage as a treatment against the ESKAPE pathogens and the advantages of using lytic phage over temperate, the immune response to phages, and phages in combinational therapies. The interaction between bacteria and bacteriophages in humans and countless animal models can also be used to design novel and futuristic therapeutics like personalised medicine or bacteriophages as anti-biofilm agents. Hence, this review explores different aspects of phage therapy and its potential to emerge as a frontline therapy against the ESKAPE bacterial pathogen.
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Affiliation(s)
- Mukta Kulshrestha
- Department of Biochemistry, Central University of Rajasthan, Ajmer, 305817, India
| | - Monalisa Tiwari
- Department of Biochemistry, Central University of Rajasthan, Ajmer, 305817, India
| | - Vishvanath Tiwari
- Department of Biochemistry, Central University of Rajasthan, Ajmer, 305817, India.
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Geng H, Song L, Yang X, Xing S, Wang R, Xu Y, Jia X, Luan G. Resistance of Klebsiella pneumoniae to Phage hvKpP3 Due to High-Molecular Weight Lipopolysaccharide Synthesis Failure. Microbiol Spectr 2023; 11:e0438422. [PMID: 37022197 PMCID: PMC10269817 DOI: 10.1128/spectrum.04384-22] [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: 10/27/2022] [Accepted: 03/17/2023] [Indexed: 04/07/2023] Open
Abstract
The spread of multidrug resistant and hypervirulent Klebsiella pneumoniae has recently increased. Phages have been considered alternatives for treating infections caused by tenacious pathogens. Our study describes a novel lytic Klebsiella phage, hvKpP3, and we obtained spontaneous mutants, hvKpP3R and hvKpP3R15, of hvKpLS8 strain that showing strong resistance to the lytic phage hvKpP3. Sequencing analysis showed that nucleotide-deletion mutations of the glycosyltransferase gene (GT) and wcaJ genes, located in the lipopolysaccharide (LPS) gene cluster and the capsular polysaccharide (CPS) gene cluster, respectively, led to phage resistance. The wcaJ mutation confers the inhibition of phage adsorption by affecting the synthesis of hvKpP3R15 capsular polysaccharide, indicating that the capsule is the main adsorption receptor for bacteriophage hvKpP3. Interestingly, the phage-resistant mutant hvKpP3R has a loss-of-function mutation in GT, which is responsible for lipopolysaccharide biosynthesis. This results in the loss of high-molecular weight lipopolysaccharide (HMW-LPS), and alteration of the lipopolysaccharide structure of the bacterial cell wall confers resistance to phages. In conclusion, our study provides a detailed description of phage hvKpP3 and provides new insights into phage resistance in K. pneumoniae. IMPORTANCE Multidrug-resistant (MDR) Klebsiella pneumoniae strains pose a particular threat to human health. Therefore, it is very important for us to isolate phage and overcome phage resistance. In this study, we isolated a novel phage belonging to the Myoviridae family, hvKpP3, that exhibited high lytic activity against K2 hypervirulent K. pneumoniae. We demonstrated the excellent stability of phage hvKpP3 through in vitro and in vivo experiments, indicating its potential as a candidate for future clinical phage therapy. Furthermore, we identified that loss of function in the glycotransferase gene (GT) caused the failure of HMW-LPS synthesis, leading to phage resistance, which provides new insights into phage resistance in K. pneumoniae.
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Affiliation(s)
- Huaixin Geng
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan, China
| | - Lingjie Song
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan, China
| | - Xianggui Yang
- Department of Laboratory Medicine, Clinical Medical College and the First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan, China
| | - Siyu Xing
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan, China
| | - Rui Wang
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan, China
| | - Ying Xu
- Department of Laboratory Medicine, Clinical Medical College and the First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan, China
| | - Xu Jia
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan, China
| | - Guangxin Luan
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan, China
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Fayez MS, Hakim TA, Zaki BM, Makky S, Abdelmoteleb M, Essam K, Safwat A, Abdelsattar AS, El-Shibiny A. Morphological, biological, and genomic characterization of Klebsiella pneumoniae phage vB_Kpn_ZC2. Virol J 2023; 20:86. [PMID: 37138257 PMCID: PMC10158348 DOI: 10.1186/s12985-023-02034-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 04/07/2023] [Indexed: 05/05/2023] Open
Abstract
BACKGROUND Bacteriophages (phages) are one of the most promising alternatives to traditional antibiotic therapies, especially against multidrug-resistant bacteria. Klebsiella pneumoniae is considered to be an opportunistic pathogen that can cause life-threatening infections. Thus, this study aims at the characterization of a novel isolated phage vB_Kpn_ZC2 (ZCKP2, for short). METHODS The phage ZCKP2 was isolated from sewage water by using the clinical isolate KP/08 as a host strain. The isolated bacteriophage was purified and amplified, followed by testing of its molecular weight using Pulse-Field Gel Electrophoresis (PFGE), transmission electron microscopy, antibacterial activity against a panel of other Klebsiella pneumoniae hosts, stability studies, and whole genome sequencing. RESULTS Phage ZCKP2 belongs morphologically to siphoviruses as indicated from the Transmission Electron Microscopy microgram. The Pulsed Field Gel Electrophoresis and the phage sequencing estimated the phage genome size of 48.2 kbp. Moreover, the absence of lysogeny-related genes, antibiotic resistance genes, and virulence genes in the annotated genome suggests that phage ZCKP2 is safe for therapeutic use. Genome-based taxonomic analysis indicates that phage ZCKP2 represents a new family that has not been formally rated yet. In addition, phage ZCKP2 preserved high stability at different temperatures and pH values (-20 - 70 °C and pH 4 - 9). For the antibacterial activity, phage ZCKP2 maintained consistent clear zones on KP/08 bacteria along with other hosts, in addition to effective bacterial killing over time at different MOIs (0.1, 1, and 10). Also, the genome annotation predicted antibacterial lytic enzymes. Furthermore, the topology of class II holins was predicted in some putative proteins with dual transmembrane domains that contribute significantly to antibacterial activity. Phage ZCKP2 characterization demonstrates safety and efficiency against multidrug-resistant K. pneumoniae, hence ZCKP2 is a good candidate for further in vivo and phage therapy clinical applications.
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Affiliation(s)
- Mohamed S. Fayez
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, 12578 Egypt
| | - Toka A. Hakim
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, 12578 Egypt
| | - Bishoy Maher Zaki
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, 12578 Egypt
- Microbiology and Immunology Department, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), Giza, 11787 Egypt
| | - Salsabil Makky
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, 12578 Egypt
| | - Mohamed Abdelmoteleb
- Department of Botany, Faculty of Science, Mansoura University, Mansoura, 35516 Egypt
| | - Kareem Essam
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, 12578 Egypt
| | - Anan Safwat
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, 12578 Egypt
| | - Abdallah S. Abdelsattar
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, 12578 Egypt
| | - Ayman El-Shibiny
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, 12578 Egypt
- Faculty of Environmental Agricultural Sciences, Arish University, Arish, 45511 Egypt
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Zaki BM, Hussein AH, Hakim TA, Fayez MS, El-Shibiny A. Phages for treatment of Klebsiella pneumoniae infections. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2023; 200:207-239. [PMID: 37739556 DOI: 10.1016/bs.pmbts.2023.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/24/2023]
Abstract
Klebsiella pneumoniae is an opportunistic pathogen involved in both hospital- and community-acquired infections. K. pneumoniae is associated with various infections, including pneumonia, septicemia, meningitis, urinary tract infection, and surgical wound infection. K. pneumoniae possesses serious virulence, biofilm formation ability, and severe resistance to many antibiotics especially hospital-acquired strains, due to excessive use in healthcare systems. This limits the available effective antibiotics that can be used for patients suffering from K. pneumoniae infections; therefore, alternative treatments are urgently needed. Bacteriophages (for short, phages) are prokaryotic viruses capable of infecting, replicating, and then lysing (lytic phages) the bacterial host. Phage therapy exhibited great potential for treating multidrug-resistant bacterial infections comprising K. pneumoniae. Hence, this chapter emphasizes and summarizes the research articles in the PubMed database from 1948 until the 15th of December 2022, addressing phage therapy against K. pneumoniae. The chapter provides an overview of K. pneumoniae phages covering different aspects, including phage isolation, different morphotypes of isolated phages, in vitro characterization, anti-biofilm activity, various therapeutic forms, in vivo research and clinical studies.
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Affiliation(s)
- Bishoy Maher Zaki
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, Egypt; Microbiology and Immunology Department, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), Giza, Egypt
| | - Assmaa H Hussein
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, Egypt
| | - Toka A Hakim
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, Egypt
| | - Mohamed S Fayez
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, Egypt
| | - Ayman El-Shibiny
- Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, Egypt; Faculty of Environmental Agricultural Sciences, Arish University, Arish, Egypt.
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6
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Mohammadi M, Saffari M, Siadat SD. Phage therapy of antibiotic-resistant strains of Klebsiella pneumoniae, opportunities and challenges from the past to the future. Folia Microbiol (Praha) 2023; 68:357-368. [PMID: 37036571 DOI: 10.1007/s12223-023-01046-y] [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: 10/07/2022] [Accepted: 03/12/2023] [Indexed: 04/11/2023]
Abstract
Klebsiella spp. is a commensal gram-negative bacterium and a member of the human microbiota. It is the leading cause of various hospital-acquired infections. The occurrence of multi-drug drug resistance and carbapenemase-producing strains of Klebsiella pneumoniae producing weighty contaminations is growing, and Klebsiella oxytoca is an arising bacterium. Alternative approaches to tackle contaminations led by these microorganisms are necessary as strains enhance opposing to last-stage antibiotics in the way that Colistin. The lytic bacteriophages are viruses that infect and rapidly eradicate bacterial cells and are strain-specific to their hosts. They and their proteins are immediately deliberate as opportunities or adjuncts to antibiotic therapy. There are several reports in vitro and in vivo form that proved the potential use of lytic phages to combat superbug stains of K. pneumoniae. Various reports dedicated that the phage area can be returned to the elimination of multi-drug resistance and carbapenemase resistance isolates of K. pneumoniae. This review compiles our current information on phages of Klebsiella spp. and highlights technological and biological issues related to the evolution of phage-based therapies targeting these bacterial hosts.
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Affiliation(s)
- Mehrdad Mohammadi
- Department of Microbiology and Immunology, Faculty of Medicine, Kashan University of Medical Sciences, Kashan, Iran.
| | - Mahmood Saffari
- Department of Microbiology and Immunology, Faculty of Medicine, Kashan University of Medical Sciences, Kashan, Iran
| | - Seyed Davar Siadat
- Tuberculosis and Pulmonary Research Department, Pasteur Institute of Iran, Tehran, Iran
- Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
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Balcão VM, Moreli FC, Silva EC, Belline BG, Martins LF, Rossi FPN, Pereira C, Vila MMDC, da Silva AM. Isolation and Molecular Characterization of a Novel Lytic Bacteriophage That Inactivates MDR Klebsiella pneumoniae Strains. Pharmaceutics 2022; 14:pharmaceutics14071421. [PMID: 35890314 PMCID: PMC9324672 DOI: 10.3390/pharmaceutics14071421] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/02/2022] [Accepted: 07/05/2022] [Indexed: 02/07/2023] Open
Abstract
The worldwide increase in serious infections caused by multidrug-resistant (MDR) K. pneumoniae emphasizes the urgent need of new therapeutic strategies for the control of this pathogen. There is growing interest in the use of bacteriophages (or phages) to treat K. pneumoniae infections, and newly isolated phages are needed. Here, we report the isolation and physical/biological/molecular characterization of a novel lytic phage and its efficacy in the control of MDR K. pneumoniae. The phage vB_KpnS_Uniso31, referred to hereafter as phage Kpn31, was isolated from hospital wastewater using K. pneumoniae CCCD-K001 as the host. Phage Kpn31 presents a siphovirus-like morphotype and was classified as Demerecviridae; Sugarlandvirus based on its complete genome sequence. The 113,444 bp Kpn31 genome does not encode known toxins or antimicrobial resistance genes, nor does it encode depolymerases related sequences. Phage Kpn31 showed an eclipse time of 15 min and a burst size of 9.12 PFU/host cell, allowing us to conclude it replicates well in K. pneumoniae CCCD-K001 with a latency period of 30 min. Phage Kpn31 was shown to be effective against at least six MDR K. pneumoniae clinical isolates in in vitro antibacterial activity assays. Based on its features, phage Kpn31 has potential for controlling infections caused by MDR K. pneumoniae.
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Affiliation(s)
- Victor M Balcão
- PhageLab, Laboratory of Biofilms and Bacteriophages, University of Sorocaba, Sorocaba 18023-000, Brazil
- Department of Biology and CESAM, Campus Universitário de Santiago, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Fernanda C Moreli
- PhageLab, Laboratory of Biofilms and Bacteriophages, University of Sorocaba, Sorocaba 18023-000, Brazil
| | - Erica C Silva
- PhageLab, Laboratory of Biofilms and Bacteriophages, University of Sorocaba, Sorocaba 18023-000, Brazil
| | - Bianca G Belline
- PhageLab, Laboratory of Biofilms and Bacteriophages, University of Sorocaba, Sorocaba 18023-000, Brazil
| | - Layla F Martins
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo 05508-000, Brazil
| | - Fernando P N Rossi
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo 05508-000, Brazil
| | - Carla Pereira
- Department of Biology and CESAM, Campus Universitário de Santiago, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Marta M D C Vila
- PhageLab, Laboratory of Biofilms and Bacteriophages, University of Sorocaba, Sorocaba 18023-000, Brazil
| | - Aline M da Silva
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo 05508-000, Brazil
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Lu B, Yao X, Han G, Luo Z, Zhang J, Yong K, Wang Y, Luo Y, Yang Z, Ren M, Cao S. Isolation of Klebsiella pneumoniae Phage vB_KpnS_MK54 and Pathological Assessment of Endolysin in the Treatment of Pneumonia Mice Model. Front Microbiol 2022; 13:854908. [PMID: 35387089 PMCID: PMC8978833 DOI: 10.3389/fmicb.2022.854908] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/01/2022] [Indexed: 11/19/2022] Open
Abstract
With the improper use of antibiotics, an increasing number of multidrug-resistant bacteria have been reported worldwide, posing challenges for disease treatment. Klebsiella pneumoniae is an important zoonotic pathogen that colonises the respiratory tract. Endolysin therapy has emerged with the development of phages. In this study, a lytic phage vB_KpnS_MK54 was isolated from the drinking water of a forest musk deer (FMD) farm in Sichuan Province. It was the first reported phage obtained from FMD. The primary biological characteristics were determined, and whole-genome sequencing analysis was performed. The phage which belongs to the family Siphoviridae is highly specific for lytic host bacteria and is moderately adaptable to different environments. Whole-genome sequencing results showed that the phage genome size was 46,218 bp. There were 80 coding DNA sequences (CDSs) in total, 32 of which had known functions. The last CDS is the phage endolysin LysG24. A new peptide-modified endolysin (LysCA) was constituted by connecting the cecropin A peptide residues with LysG24 to investigate the antibacterial activities of both LysG24 and LysCA. The results showed that the lytic profile of LysG24 and LysCA was wider than that of phage MK54. For in vitro tests, both endolysins destroyed 99% of the host bacteria within 6 h. The lysing ability and environmental adaptability of LysCA were significantly stronger than those of LysG24. For in vivo tests, LysG24 and LysCA exhibited therapeutic effects in a mouse model of pneumonia wherewith the mice were infected with K. pneumoniae (LPKP), wherein both LysG24 and LysCA can effectively reduce the pulmonary inflammatory response. The LPKP bacterial load in the treatment group was significantly lower than that in the bacterial group, among which LysCA displayed a more obvious therapeutic effect. Furthermore, the safety test showed that the endolysins had no toxic effects on mice. In general, both LysG24 and LysCA showed excellent antibacterial activity in vivo and in vitro, with high safety and strong adaptability to the environment, manifesting their latent potential as new antimicrobial agents.
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Affiliation(s)
- Biao Lu
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Xueping Yao
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Guangli Han
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Zidan Luo
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Jieru Zhang
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Kang Yong
- College of Animal Science and Technology, Chongqing Three Gorges Vocational College, Chongqing, China
| | - Yin Wang
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Yan Luo
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Zexiao Yang
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Meishen Ren
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Suizhong Cao
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
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