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Liu C, Qian R, Shi W, Kou L, Wang J, Ma X, Ren H, Gao S, Ren J. EⅡB Mutation Reduces the Pathogenicity of Listeria monocytogenes by Negatively Regulating Biofilm Formation Ability, Infective Capacity, and Virulence Gene Expression. Vet Sci 2024; 11:301. [PMID: 39057985 PMCID: PMC11281496 DOI: 10.3390/vetsci11070301] [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: 05/14/2024] [Revised: 06/28/2024] [Accepted: 06/30/2024] [Indexed: 07/28/2024] Open
Abstract
To explore the role of the membrane permease ⅡB (EⅡB) gene of Listeria pathogenicity island 4 (LIPI-4) in the virulence of Listeria monocytogenes, both an EⅡB deletion strain (∆EⅡB) and a complemented strain were constructed. In vitro experiments demonstrated that EⅡB deletion affected the biofilm formation ability of the wild-type strain (Lm928). Moreover, this deletion decreased the intracellular proliferation abilities of L. monocytogenes. Mice infected with ∆EⅡB survived longer and experienced less weight loss on days 1, 2, and 3 post-infection. The bacterial load in the liver tissue of ∆EⅡB-infected mice was significantly reduced, and a considerable decrease in the blood levels of inflammatory cytokines IL-β, IL-6, IL-10, and TNF-α were observed. Following EⅡB deletion, 65% (13/20) of genes were downregulated, 25% (5/20) were upregulated, and 10% (2/20) showed no change. These findings suggest that EⅡB deletion may reduce both the in vivo and in vitro virulence levels as well as the biofilm formation ability of Lm928 by downregulating the transcription levels of genes associated with virulence and biofilm formation. These findings provide a foundation for further examining the pathogenic mechanisms of LIPI-4 and EⅡB in L. monocytogenes.
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Affiliation(s)
| | | | | | | | - Jing Wang
- College of Animal Science and Technology, Shihezi University, Shihezi 832000, China; (C.L.); (R.Q.); (W.S.); (L.K.); (H.R.); (S.G.); (J.R.)
| | - Xun Ma
- College of Animal Science and Technology, Shihezi University, Shihezi 832000, China; (C.L.); (R.Q.); (W.S.); (L.K.); (H.R.); (S.G.); (J.R.)
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Pérez Jorge G, Gontijo M, Silva MFE, Goes ICRDS, Jaimes-Florez YP, Coser LDO, Rocha FJS, Giorgio S, Brocchi M. Attenuated mutants of Salmonella enterica Typhimurium mediate melanoma regression via an immune response. Exp Biol Med (Maywood) 2024; 249:10081. [PMID: 38974834 PMCID: PMC11224151 DOI: 10.3389/ebm.2024.10081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Accepted: 05/07/2024] [Indexed: 07/09/2024] Open
Abstract
The lack of effective treatment options for an increasing number of cancer cases highlights the need for new anticancer therapeutic strategies. Immunotherapy mediated by Salmonella enterica Typhimurium is a promising anticancer treatment. Candidate strains for anticancer therapy must be attenuated while retaining their antitumor activity. Here, we investigated the attenuation and antitumor efficacy of two S. enterica Typhimurium mutants, ΔtolRA and ΔihfABpmi, in a murine melanoma model. Results showed high attenuation of ΔtolRA in the Galleria mellonella model, and invasion and survival in tumor cells. However, it showed weak antitumor effects in vitro and in vivo. Contrastingly, lower attenuation of the attenuated ΔihfABpmi strain resulted in regression of tumor mass in all mice, approximately 6 days after the first treatment. The therapeutic response induced by ΔihfABpmi was accompanied with macrophage accumulation of antitumor phenotype (M1) and significant increase in the mRNAs of proinflammatory mediators (TNF-α, IL-6, and iNOS) and an apoptosis inducer (Bax). Our findings indicate that the attenuated ΔihfABpmi exerts its antitumor activity by inducing macrophage infiltration or reprogramming the immunosuppressed tumor microenvironment to an activated state, suggesting that attenuated S. enterica Typhimurium strains based on nucleoid-associated protein genes deletion could be immunotherapeutic against cancer.
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Affiliation(s)
- Genesy Pérez Jorge
- Departamento de Genética, Evolução, Microbiologia e Immunologia, Instituto de Biologia, Universidade Estadual de Campinas—UNICAMP, Campinas, SP, Brazil
- Research Group: Statistics and Mathematical Modeling Applied to Educational Quality, University of Sucre, Sincelejo, Sucre, Colombia
| | - Marco Gontijo
- Departamento de Genética, Evolução, Microbiologia e Immunologia, Instituto de Biologia, Universidade Estadual de Campinas—UNICAMP, Campinas, SP, Brazil
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Duke Medicine Cir, Durham, NC, United States
| | - Marina Flóro e Silva
- Departamento de Genética, Evolução, Microbiologia e Immunologia, Instituto de Biologia, Universidade Estadual de Campinas—UNICAMP, Campinas, SP, Brazil
- Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas—UNICAMP, Campinas, SP, Brazil
| | | | - Yessica Paola Jaimes-Florez
- Departamento de Genética, Evolução, Microbiologia e Immunologia, Instituto de Biologia, Universidade Estadual de Campinas—UNICAMP, Campinas, SP, Brazil
- GIMBIO Group, Department of Microbiology, Faculty of Basic Sciences, Universidad de Pamplona, Pamplona, Colombia
| | - Lilian de Oliveira Coser
- Departamento de Biologia Estrutural e Funcional, Laboratório de Regeneração Nervosa, Instituto de Biologia, Universidade Estadual de Campinas—UNICAMP, Campinas, SP, Brazil
| | - Francisca Janaína Soares Rocha
- Área Acadêmica de Medicina Tropical, Centro de Ciências Médicas, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil
| | - Selma Giorgio
- Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas—UNICAMP, Campinas, SP, Brazil
| | - Marcelo Brocchi
- Departamento de Genética, Evolução, Microbiologia e Immunologia, Instituto de Biologia, Universidade Estadual de Campinas—UNICAMP, Campinas, SP, Brazil
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García P, Moscoso M, Fuentes-Valverde V, Rodicio MR, Herrera-León S, Bou G. A highly-safe live auxotrophic vaccine protecting against disease caused by non-typhoidal Salmonella Typhimurium in mice. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2023; 56:324-336. [PMID: 37610206 DOI: 10.1016/j.jmii.2022.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 09/26/2022] [Accepted: 10/06/2022] [Indexed: 11/06/2022]
Abstract
BACKGROUND Salmonella enterica serovar Typhimurium (S. Typhimurium) has become an important intestinal pathogen worldwide and is responsible for lethal invasive infections in populations at risk. There is at present an unmet need for preventive vaccines. METHODS IRTA GN-3728 genome was sequenced by Illumina and d-glutamate and d-glutamate/d-alanine knockout-auxotrophs were constructed. They were characterized using electron microscopy, growth/viability curves, reversion analysis, and motility/agglutination assays. Their potential as vaccine candidates were explored using two BALB/c mouse models for Salmonella infections: a systemic and an intestinal inflammation. Clinical signs/body weight and survival were monitored, mucosal lactoferrin and specific/cross-reactive IgA/IgG were quantified by enzyme-linked-immunosorbent assays and bacterial shedding/burden in fecal/tissues were evaluated. RESULTS The d-glutamate auxotroph, IRTA ΔmurI, is highly attenuated, immunogenic and fully protective against systemic infection. The IRTA ΔmurI Δalr ΔdadX double auxotroph, constructed to reinforce vaccine safety, showed a higher level of attenuation and was 100% effective against systemic disease. In the intestinal model, it proved to be safe, yielding a low-degree of mucosal inflammation, short-term shedding and undetectable invasiveness in the long-term, while eliciting cross-reactive fecal IgA/serum IgG against clinically relevant multidrug-resistant (MDR) S. Typhimurium strains. It also conferred protection against homologous oral challenge, and protected mice from local and extra-intestinal dissemination caused by one MDR strain responsible for an international outbreak of highly severe human infections. Additionally, oral vaccination promoted extended survival after lethal heterologous infection. CONCLUSION This study yielded a very safe S. Typhimurium vaccine candidate that could be further refined for mucosal application against disease in humans.
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Affiliation(s)
- Patricia García
- Department of Microbiology, University Hospital A Coruña (CHUAC) - Biomedical Research Institute A Coruña (INIBIC), 15006 - A Coruña, Spain.
| | - Miriam Moscoso
- Department of Microbiology, University Hospital A Coruña (CHUAC) - Biomedical Research Institute A Coruña (INIBIC), 15006 - A Coruña, Spain.
| | - Víctor Fuentes-Valverde
- Department of Microbiology, University Hospital A Coruña (CHUAC) - Biomedical Research Institute A Coruña (INIBIC), 15006 - A Coruña, Spain; Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28029 - Madrid, Spain.
| | - M Rosario Rodicio
- Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo, 33006 - Oviedo, Spain; Grupo de Microbiología Traslacional, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 - Oviedo, Spain.
| | - Silvia Herrera-León
- Laboratorio de Referencia e Investigación en Enfermedades Bacterianas Transmitidas por Alimentos, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220, Madrid, Spain.
| | - Germán Bou
- Department of Microbiology, University Hospital A Coruña (CHUAC) - Biomedical Research Institute A Coruña (INIBIC), 15006 - A Coruña, Spain; Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28029 - Madrid, Spain.
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Huang Z, Dong W, Fan J, Tian Y, Huang A, Wang X. Tandem mass tag-based proteomics technology provides insights into multi-targeted mechanism of peptide MOp2 from Moringa oleifera seeds against Staphylococcus aureus. Lebensm Wiss Technol 2023. [DOI: 10.1016/j.lwt.2023.114617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
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Confirmation of Glucose Transporters through Targeted Mutagenesis and Transcriptional Analysis in Clostridium acetobutylicum. FERMENTATION 2023. [DOI: 10.3390/fermentation9010064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The solvent-producing bacterium Clostridium acetobutylicum is able to grow on a variety of carbohydrates. The main hexose transport system is the phosphoenolpyruvate-dependent phosphotransferase system (PTS). When the gene glcG that encodes the glucose transporter was inactivated, the resulting mutant glcG::int(1224) grew as well as the wild type, yet its glucose consumption was reduced by 17% in a batch fermentation. Transcriptomics analysis of the phosphate-limited continuous cultures showed that the cellobiose transporter GlcCE was highly up-regulated in the mutant glcG::int(1224). The glcCE mutation did not affect growth and even consumed slightly more glucose during solventogenesis growth compared to wild type, indicating that GlcG is the primary glucose-specific PTS. Poor growth of the double mutant glcG::int(1224)-glcCE::int(193) further revealed that GlcCE was the secondary glucose PTS and that there must be other PTSs capable of glucose uptake. The observations obtained in this study provided a promising foundation to understand glucose transport in C. acetobutylicum.
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Hu J, Che C, Zuo J, Niu X, Wang Z, Lian L, Jia Y, Zhang H, Zhang T, Yu F, Nawaz S, Han X. Effect of Antibiotics on the Colonization of Live Attenuated Salmonella Enteritidis Vaccine in Chickens. Front Vet Sci 2021; 8:784160. [PMID: 34926647 PMCID: PMC8671454 DOI: 10.3389/fvets.2021.784160] [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: 09/27/2021] [Accepted: 11/03/2021] [Indexed: 12/19/2022] Open
Abstract
Salmonellosis, caused by Salmonella Enteritidis, is a prevalent zoonosis that has serious consequences for human health and the development of the poultry sector. The Salmonella Enteritis live vaccine (Sm24/Rif12/Ssq strain) is used to prevent Salmonella Enteritidis around the world. However, in some parts of the world, poultry flocks are frequently raised under intensive conditions, with significant amounts of antimicrobials to prevent and treat disease and to promote growth. To investigate whether antibiotic use influences the colonization of orally administered Salmonella live vaccines, 240 1-day-old specific pathogen-free chicks were randomly divided into 24 groups of 10 animals for this study. The different groups were treated with different antibiotics, which included ceftiofur, amoxicillin, enrofloxacin, and lincomycin–spectinomycin. Each group was immunized 2, 3, 4, and 5 days after withdrawal, respectively. At 5 days after immunization, the blood, liver, and ceca with contents were collected for the isolation of the Salmonella live vaccine strain. The result showed that no Salmonella vaccine strain was isolated in the blood and liver of the chicks in those groups. The highest number of Salmonella vaccine strains was isolated in the cecum from chicks vaccinated 2 days after ceftiofur withdrawal, and no Salmonella vaccine strain was isolated from the cecum in chicks immunized 3 days after ceftiofur withdrawal. Among the chickens immunized 4 days after the withdrawal of amoxicillin, enrofloxacin, and lincomycin–spectinomycin, the number of Salmonella vaccine colonization in the cecum was the highest, which was higher than that of the chickens immunized at other withdrawal interval (2, 3, and 5 days) groups and was higher than that of the chickens without treatment (P < 0.05). This study provides a reference for the effective use of the Salmonella Enteritidis live vaccine and key antibiotics commonly utilized in the poultry industry.
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Affiliation(s)
- Jiangang Hu
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Chuanyan Che
- College of Animal Science, Anhui Science and Technology University, Chuzhou, China
| | - Jiakun Zuo
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Xiangpeng Niu
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Zhihao Wang
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Liyan Lian
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Yuanzheng Jia
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Haiyang Zhang
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Tao Zhang
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Fangheng Yu
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Saqib Nawaz
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Xiangan Han
- Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Shanghai, China
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Regulator of ribonuclease activity modulates the pathogenicity of Vibrio vulnificus. J Microbiol 2021; 59:1133-1141. [PMID: 34751908 DOI: 10.1007/s12275-021-1518-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 12/19/2022]
Abstract
RraA, a protein regulator of RNase E activity, plays a unique role in modulating the mRNA abundance in Escherichia coli. The marine pathogenic bacterium Vibrio vulnificus also possesses homologs of RNase E (VvRNase E) and RraA (VvRraA1 and VvRraA2). However, their physiological roles have not yet been investigated. In this study, we demonstrated that VvRraA1 expression levels affect the pathogenicity of V. vulnificus. Compared to the wild-type strain, the VvrraA1-deleted strain (ΔVvrraA1) showed decreased motility, invasiveness, biofilm formation ability as well as virulence in mice; these phenotypic changes of ΔVvrraA1 were restored by the exogenous expression of VvrraA1. Transcriptomic analysis indicated that VvRraA1 expression levels affect the abundance of a large number of mRNA species. Among them, the half-lives of mRNA species encoding virulence factors (e.g., smcR and htpG) that have been previously shown to affect VvrraA1 expression-dependent phenotypes were positively correlated with VvrraA1 expression levels. These findings suggest that VvRraA1 modulates the pathogenicity of V. vulnificus by regulating the abundance of a subset of mRNA species.
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Swietnicki W. Secretory System Components as Potential Prophylactic Targets for Bacterial Pathogens. Biomolecules 2021; 11:892. [PMID: 34203937 PMCID: PMC8232601 DOI: 10.3390/biom11060892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 06/13/2021] [Accepted: 06/14/2021] [Indexed: 01/18/2023] Open
Abstract
Bacterial secretory systems are essential for virulence in human pathogens. The systems have become a target of alternative antibacterial strategies based on small molecules and antibodies. Strategies to use components of the systems to design prophylactics have been less publicized despite vaccines being the preferred solution to dealing with bacterial infections. In the current review, strategies to design vaccines against selected pathogens are presented and connected to the biology of the system. The examples are given for Y. pestis, S. enterica, B. anthracis, S. flexneri, and other human pathogens, and discussed in terms of effectiveness and long-term protection.
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Affiliation(s)
- Wieslaw Swietnicki
- Department of Immunology of Infectious Diseases, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, ul. R. Weigla 12, 53-114 Wroclaw, Poland
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Transporters of glucose and other carbohydrates in bacteria. Pflugers Arch 2020; 472:1129-1153. [PMID: 32372286 DOI: 10.1007/s00424-020-02379-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 12/18/2022]
Abstract
Glucose arguably is the most important energy carrier, carbon source for metabolites and building block for biopolymers in all kingdoms of life. The proper function of animal organs and tissues depends on the continuous supply of glucose from the bloodstream. Most animals can resorb only a small number of monosaccharides, mostly glucose, galactose and fructose, while all other sugars oligosaccharides and dietary fibers are degraded and metabolized by the microbiota of the lower intestine. Bacteria, in contrast, are omnivorous. They can import and metabolize structurally different sugars and, as a consortium of different species, utilize almost any sugar, sugar derivative and oligosaccharide occurring in nature. Bacteria have membrane transport systems for the uptake of sugars against steep concentration gradients energized by ATP, the proton motive force and the high energy glycolytic intermediate phosphoenolpyruvate (PEP). Different uptake mechanisms and the broad range of overlapping substrate specificities allow bacteria to quickly adapt to and colonize changing environments. Here, we review the structures and mechanisms of bacterial representatives of (i) ATP-dependent cassette (ABC) transporters, (ii) major facilitator (MFS) superfamily proton symporters, (iii) sodium solute symporters (SSS) and (iv) enzyme II integral membrane subunits of the bacterial PEP-dependent phosphotransferase system (PTS). We give a short overview on the distribution of transporter genes and their phylogenetic relationship in different bacterial species. Some sugar transporters are hijacked for import of bacteriophage DNA and antibacterial toxins (bacteriocins) and they facilitate the penetration of polar antibiotics. Finally, we describe how the expression and activity of certain sugar transporters are controlled in response to the availability of sugars and how the presence and uptake of sugars may affect pathogenicity and host-microbiota interactions.
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Development of Oxytolerant Salmonella typhimurium Using Radiation Mutation Technology (RMT) for Cancer Therapy. Sci Rep 2020; 10:3764. [PMID: 32111878 PMCID: PMC7048768 DOI: 10.1038/s41598-020-60396-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 02/05/2020] [Indexed: 02/02/2023] Open
Abstract
A critical limitation of Salmonella typhimurium (S. typhimurium) as an anti-cancer agent is the loss of their invasive or replicative activities, which results in no or less delivery of anti-cancer agents inside cancer cells in cancer therapy. Here we developed an oxytolerant attenuated Salmonella strain (KST0650) from the parental KST0649 (ΔptsIΔcrr) strain using radiation mutation technology (RMT). The oxytolerant KST0650 strain possessed 20-times higher replication activity in CT26 cancer cells and was less virulent than KST0649. Furthermore, KST0650 migrated effectively into tumor tissues in mice. KST0650 was further equipped with a plasmid harboring a spliced form of the intracellular pro-apoptotic protein sATF6, and the expression of sATF6 was controlled by the radiation-inducible recN promoter. The new strain was named as KST0652, in which sATF6 protein expression was induced in response to radiation in a dose-dependent manner. This strain was effectively delivered inside cancer cells and tumor tissues via the Salmonella type III secretion system (T3SS). In addition, combination treatment with KST0652 and radiation showed a synergistic anti-tumor effect in murine tumor model with complete inhibition of tumor growth and protection against death. In conclusion, we showed that RMT can be used to effectively develop an anti-tumor Salmonella strain for delivering anti-cancer agents inside tumors.
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Zhi Y, Lin SM, Ahn KB, Ji HJ, Guo HC, Ryu S, Seo HS, Lim S. ptsI gene in the phosphotransfer system is a potential target for developing a live attenuated Salmonella vaccine. Int J Mol Med 2020; 45:1327-1340. [PMID: 32323733 PMCID: PMC7138283 DOI: 10.3892/ijmm.2020.4505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 01/07/2020] [Indexed: 11/15/2022] Open
Abstract
Salmonella enterica serovar Typhimurium causes invasive non-typhoidal Salmonella diseases in animals and humans, resulting in a high mortality rate and huge economic losses globally. As the prevalence of antibiotic-resistant Salmonella has been increasing, vaccination is thought to be the most effective and economical strategy to manage salmonellosis. The present study aimed to investigate whether dysfunction in the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS), which is critical for carbon uptake and survival in macrophages, may be adequate to generate Salmonella-attenuated vaccine strains. A Salmonella strain (KST0555) was generated by deleting the ptsI gene from the PTS and it was revealed that this auxotrophic mutant was unable to efficiently utilize predominant carbon sources during infection (glucose and glycerol), reduced its invasion and replication capacity in macrophages, and significantly (P=0.0065) lowered its virulence in the setting of a mouse colitis model, along with a substantially decreased intestinal colonization and invasiveness compared with its parent strain. The reverse transcription-quantitative PCR results demonstrated that the virulence genes in Salmonella pathogenicity island-1 (SPI-1) and -2 (SPI-2) and the motility of KST0555 were all downregulated compared with its parent strain. Finally, it was revealed that when mice were immunized orally with live KST0555, Salmonella-specific humoral and cellular immune responses were effectively elicited, providing protection against Salmonella infection. Thus, the present promising data provides a strong rationale for the advancement of KST0555 as a live Salmonella vaccine candidate and ptsI as a potential target for developing a live attenuated bacterial vaccine strain.
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Affiliation(s)
- Yong Zhi
- Radiation Science Division, Korea Atomic Energy Research Institute, Jeongeup, Jeollabookdo 56212, Republic of Korea
| | - Shun Mei Lin
- Radiation Science Division, Korea Atomic Energy Research Institute, Jeongeup, Jeollabookdo 56212, Republic of Korea
| | - Ki Bum Ahn
- Radiation Science Division, Korea Atomic Energy Research Institute, Jeongeup, Jeollabookdo 56212, Republic of Korea
| | - Hyun Jung Ji
- Radiation Science Division, Korea Atomic Energy Research Institute, Jeongeup, Jeollabookdo 56212, Republic of Korea
| | - Hui-Chen Guo
- State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730049, P.R. China
| | - Sangryeol Ryu
- Department of Food and Animal Biotechnology, Seoul National University, Seoul 08826, Republic of Korea
| | - Ho Seong Seo
- Radiation Science Division, Korea Atomic Energy Research Institute, Jeongeup, Jeollabookdo 56212, Republic of Korea
| | - Sangyong Lim
- Radiation Science Division, Korea Atomic Energy Research Institute, Jeongeup, Jeollabookdo 56212, Republic of Korea
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