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He Q, Zheng Y, Yan K, Tang J, Yang F, Tian Y, Yang L, Dou B, Chen Y, Gu J, Chen H, Yuan F, Bei W. The cAMP receptor protein gene contributes to growth, stress resistance, and colonization of Actinobacillus pleuropneumoniae. Vet Microbiol 2024; 290:110006. [PMID: 38308931 DOI: 10.1016/j.vetmic.2024.110006] [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: 09/11/2023] [Revised: 01/15/2024] [Accepted: 01/18/2024] [Indexed: 02/05/2024]
Abstract
Porcine infectious pleuropneumonia (PCP) is a severe disease of porcine caused by Actinobacillus pleuropneumoniae (APP). The spread of PCP remains a threat to the porcine farms and has been known to cause severe economic losses. The cAMP receptor protein (CRP) serves as a pivotal player in helping bacteria adapt to shifts in their environment, particularly when facing the challenges posed by bacterial infections. In this study, we investigated the role of CRP in APP. Our results revealed that crp mutant (Δcrp) strains were more sensitive to acidic and osmotic stress resistance and had lower biofilm formation ability than wild-type (WT) strains. Furthermore, the Δcrp strains showed deficiencies in anti-phagocytosis, adhesion, and invasion upon interaction with host cells. Mice infected with the Δcrp strains demonstrated reduced bacterial loads in their lungs compared to those infected with the WT strains. This study reveals the pivotal role of crp gene expression in regulating pleuropneumonia growth, stress resistance, iron utilization, biofilm formation, phagocytosis, adhesion, invasion and colonization. Our discoveries offer novel perspectives on understanding the development and progression of APP infections.
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Affiliation(s)
- Qiyun He
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine,Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Yaxuan Zheng
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine,Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Kang Yan
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine,Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Jia Tang
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine,Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Fengming Yang
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine,Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Yanhong Tian
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine,Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Lijun Yang
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine,Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Beibei Dou
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine,Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Yunpeng Chen
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine,Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Jun Gu
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine,Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Huanchun Chen
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine,Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Fangyan Yuan
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture), Institute of Animal Husbandry and Veterinary Sciences, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Weicheng Bei
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine,Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China.
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Sawant K, Shashidhar R. The cAMP receptor protein (CRP) enhances the competitive nature of Salmonella Typhimurium. Arch Microbiol 2023; 205:197. [PMID: 37067650 DOI: 10.1007/s00203-023-03528-6] [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: 06/23/2022] [Revised: 03/27/2023] [Accepted: 03/29/2023] [Indexed: 04/18/2023]
Abstract
The cAMP receptor protein (CRP) is a global regulatory protein. We evaluated the role of CRP in starvation physiology in Salmonella Typhimurium. The Δcrp mutant survived 10 days of starvation. However, in a co-culture with the wild type in nutrient-rich medium, Δcrp died within 48 h. Similar co-culture results were observed with Escherichia coli and Staphylococcus aureus. Our study showed that the Δcrp mutant was not killed by toxins and the Type IV secretion system of the WT. The possibility of viable but non-culturable cells (VBNC) was also ruled out. However, when the overall metabolism of the co-culture was slowed down (anaerobic condition, inhibition by antibiotics and low temperature) that improved the survival of Δcrp in co-culture. But one more significant observation was that the Δcrp mutant survived in nutrient-free co-culture conditions. These two observations suggest that CRP protein is essential for efficient nutrient assimilation in a competitive environment. The cells without CRP protein are unable to evaluate the energy balance within the cell, and the cell spends energy to absorb nutrients. But the wild type cell absorbs nutrients at a faster rate than Δcrp mutant. This leads to a situation wherein the Δcrp is spending energy to absorb the nutrients but is unable to compete with the wild type. This futile metabolism leads to death. Hence, this study shows that CRP is a metabolism modulator in a complex nutrient environment. This study also highlights the need for innovative growth conditions to understand the unique function of a gene.
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Affiliation(s)
- Kirti Sawant
- Food Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India
| | - Ravindranath Shashidhar
- Food Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India.
- Life Sciences, Homi Bhabha National Institute (Deemed to be University), Mumbai, India.
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Genes associated with desiccation stress in foodborne Staphylococcus aureus as revealed by transposon insertion mutagenesis. Food Res Int 2023; 163:112271. [PMID: 36596182 DOI: 10.1016/j.foodres.2022.112271] [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: 08/18/2022] [Revised: 11/19/2022] [Accepted: 11/27/2022] [Indexed: 11/30/2022]
Abstract
Staphylococcus aureus (S. aureus) is an opportunistic foodborne pathogen whose survival in food processing environments may be associated with its tolerance to desiccation. However, the molecular mechanisms involved in desiccation stress have received little attention in S. aureus. Here, some potential genes related to desiccation stress were determined in S. aureus by the transposon random mutagenesis approach. Eight mutants with different mutant sites who showed lower survival rates compared to wild-type (WT) strain RMSA24 under desiccation stress were successfully screened from a mutant library (n = 3,154). The eight mutation sites are identified as potential genes of U32 family peptidase, CHAP domain-containing protein, YdcF family protein, RNA polymerase sigma factor, EVE domain-containing protein, acetyltransferase, LPXTG-anchored DUF1542 repeat protein FmtB, and CvpA family protein, which haven't been reported as the desiccation-tolerant related genes. We found that the growth rates and biofilm formation abilities of these mutants were not significantly affected, indicating that their reduced survival rates under desiccation stress not dependent on reduced growth rates and biofilm formation abilities. Under desiccation stress, the expression levels of the three mutated genes were up-regulated and the four mutated genes were down-regulated in the WT strain, implying that these genes may play different roles in S. aureus to adapt to desiccation stress conditions. The study reveals valuable information for the control of S. aureus in low water activity foods and their production environments.
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Tang X, Yang Z, Dai K, Liu G, Chang YF, Tang X, Wang K, Zhang Y, Hu B, Cao S, Huang X, Yan Q, Wu R, Zhao Q, Du S, Lang Y, Han X, Huang Y, Wen X, Wen Y. The molecular diversity of transcriptional factor TfoX is a determinant in natural transformation in Glaesserella parasuis. Front Microbiol 2022; 13:948633. [PMID: 35966685 PMCID: PMC9372613 DOI: 10.3389/fmicb.2022.948633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 07/12/2022] [Indexed: 11/13/2022] Open
Abstract
Natural transformation is a mechanism by which a particular bacterial species takes up foreign DNA and integrates it into its genome. The swine pathogen Glaesserella parasuis (G. parasuis) is a naturally transformable bacterium. The regulation of competence, however, is not fully understood. In this study, the natural transformability of 99 strains was investigated. Only 44% of the strains were transformable under laboratory conditions. Through a high-resolution melting curve and phylogenetic analysis, we found that genetic differences in the core regulator of natural transformation, the tfoX gene, leads to two distinct natural transformation phenotypes. In the absence of the tfoX gene, the highly transformable strain SC1401 lost its natural transformability. In addition, when the SC1401 tfoX gene was replaced by the tfoX of SH0165, which has no natural transformability, competence was also lost. These results suggest that TfoX is a core regulator of natural transformation in G. parasuis, and that differences in tfoX can be used as a molecular indicator of natural transformability. Transcriptomic and proteomic analyses of the SC1401 wildtype strain, and a tfoX gene deletion strain showed that differential gene expression and protein synthesis is mainly centered on pathways related to glucose metabolism. The results suggest that tfoX may mediate natural transformation by regulating the metabolism of carbon sources. Our study provides evidence that tfoX plays an important role in the natural transformation of G. parasuis.
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Affiliation(s)
- Xiaoyu Tang
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Zhen Yang
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Ke Dai
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Geyan Liu
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yung-Fu Chang
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
| | - Xinwei Tang
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Kang Wang
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yiwen Zhang
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Bangdi Hu
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Sanjie Cao
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xiaobo Huang
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Qigui Yan
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Rui Wu
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Qin Zhao
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Senyan Du
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yifei Lang
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xinfeng Han
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yong Huang
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xintian Wen
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yiping Wen
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- *Correspondence: Yiping Wen,
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Rodríguez-Valverde D, León-Montes N, Soria-Bustos J, Martínez-Cruz J, González-Ugalde R, Rivera-Gutiérrez S, González-y-Merchand JA, Rosales-Reyes R, García-Morales L, Hirakawa H, Fox JG, Girón JA, De la Cruz MA, Ares MA. cAMP Receptor Protein Positively Regulates the Expression of Genes Involved in the Biosynthesis of Klebsiella oxytoca Tilivalline Cytotoxin. Front Microbiol 2021; 12:743594. [PMID: 34659176 PMCID: PMC8515920 DOI: 10.3389/fmicb.2021.743594] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Accepted: 08/31/2021] [Indexed: 01/09/2023] Open
Abstract
Klebsiella oxytoca is a resident of the human gut. However, certain K. oxytoca toxigenic strains exist that secrete the nonribosomal peptide tilivalline (TV) cytotoxin. TV is a pyrrolobenzodiazepine that causes antibiotic-associated hemorrhagic colitis (AAHC). The biosynthesis of TV is driven by enzymes encoded by the aroX and NRPS operons. In this study, we determined the effect of environmental signals such as carbon sources, osmolarity, and divalent cations on the transcription of both TV biosynthetic operons. Gene expression was enhanced when bacteria were cultivated in tryptone lactose broth. Glucose, high osmolarity, and depletion of calcium and magnesium diminished gene expression, whereas glycerol increased transcription of both TV biosynthetic operons. The cAMP receptor protein (CRP) is a major transcriptional regulator in bacteria that plays a key role in metabolic regulation. To investigate the role of CRP on the cytotoxicity of K. oxytoca, we compared levels of expression of TV biosynthetic operons and synthesis of TV in wild-type strain MIT 09-7231 and a Δcrp isogenic mutant. In summary, we found that CRP directly activates the transcription of the aroX and NRPS operons and that the absence of CRP reduced cytotoxicity of K. oxytoca on HeLa cells, due to a significant reduction in TV production. This study highlights the importance of the CRP protein in the regulation of virulence genes in enteric bacteria and broadens our knowledge on the regulatory mechanisms of the TV cytotoxin.
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Affiliation(s)
- Diana Rodríguez-Valverde
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Nancy León-Montes
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Jorge Soria-Bustos
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | - Jessica Martínez-Cruz
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Ricardo González-Ugalde
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Sandra Rivera-Gutiérrez
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Jorge A. González-y-Merchand
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Roberto Rosales-Reyes
- Unidad de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Lázaro García-Morales
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Hidetada Hirakawa
- Department of Bacteriology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - James G. Fox
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Jorge A. Girón
- Centro de Detección Biomolecular, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Miguel A. De la Cruz
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | - Miguel A. Ares
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
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Jiang R, Xiang M, Chen W, Zhang P, Wu X, Zhu G, Tu T, Jiang D, Yao X, Luo Y, Yang Z, Chen D, Wang Y. Biofilm characteristics and transcriptomic analysis of Haemophilus parasuis. Vet Microbiol 2021; 258:109073. [PMID: 33984794 DOI: 10.1016/j.vetmic.2021.109073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 04/13/2021] [Indexed: 12/27/2022]
Abstract
Haemophilus parasuis (H. parasuis) is a conditional pathogen with the ability to form biofilms which can lead to ineffective drug treatment and severe chronic infections resulting in significant economic losses to the pig industry. Currently, knowledge of biofilm formation by H. parasuis is not well developed. The objective of this study was to investigate the three-dimensional morphology of biofilms and perform transcriptomic analysis on H. parasuis cells in biofilm versus planktonic forms. The results showed that proteins and DNA accounted for a large proportion of the H. parasuis biofilm extracellular matrix. Here, we have traced the entire biofilm formation process of H. parasuis from beginning to end for the first time. These biofilms grew rapidly in the first 48 h and became stable at 60 h. According to GO and KEGG analysis, the differentially expressed genes (DEG) artM, artQ, ssrS, pflA and HutX were implicated as being involved in bacterial colonisation and adhesion; these are the most likely genes to affect biofilm formation. Most functional gene enrichments were of those involved in metabolic pathways, biosynthesis of secondary metabolites, ATP-binding cassette (ABC) transporters, and starch and sucrose metabolism. Thus, in the present pilot study, the composition and characteristics of these biofilms were explored, and the genes related to biofilm formation were screened for. This research lays the foundation for further studies on mechanisms regulating biofilm formation, in order to find new drug targets and develop new therapeutic drugs against H. parasuis.
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Affiliation(s)
- Ruijiao Jiang
- Sichuan Provincial Key Laboratory of Animal Diseases and Human Health, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, People's Republic of China
| | - Mingyuan Xiang
- Sichuan Provincial Key Laboratory of Animal Diseases and Human Health, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Wanting Chen
- Sichuan Provincial Key Laboratory of Animal Diseases and Human Health, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Pengfei Zhang
- Sichuan Provincial Key Laboratory of Animal Diseases and Human Health, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Xulong Wu
- Branch of Animal Husbandry and Veterinary Medicine, Chengdu Agricultural College, Chengdu 611130, China
| | - Guangheng Zhu
- Sichuan Provincial Key Laboratory of Animal Diseases and Human Health, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Teng Tu
- Sichuan Provincial Key Laboratory of Animal Diseases and Human Health, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Dike Jiang
- Sichuan Provincial Key Laboratory of Animal Diseases and Human Health, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Xueping Yao
- Sichuan Provincial Key Laboratory of Animal Diseases and Human Health, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Yan Luo
- Sichuan Provincial Key Laboratory of Animal Diseases and Human Health, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Zexiao Yang
- Sichuan Provincial Key Laboratory of Animal Diseases and Human Health, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Dishi Chen
- Sichuan Animal Disease Prevention and Control Center, Chengdu 610047, China.
| | - Yin Wang
- Sichuan Provincial Key Laboratory of Animal Diseases and Human Health, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
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Ma D, Gu H, Shi Y, Huang H, Sun D, Hu Y. Edwardsiella piscicida YefM-YoeB: A Type II Toxin-Antitoxin System That Is Related to Antibiotic Resistance, Biofilm Formation, Serum Survival, and Host Infection. Front Microbiol 2021; 12:646299. [PMID: 33732226 PMCID: PMC7957083 DOI: 10.3389/fmicb.2021.646299] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 02/03/2021] [Indexed: 12/16/2022] Open
Abstract
The emergence of drug resistant bacteria is a tricky and confronted problem in modern medicine, and one of important reasons is the widespread of toxin-antitoxin (TA) systems in pathogenic bacteria. Edwardsiella piscicida (also known as E. tarda) is the leading pathogen threatening worldwide fresh and seawater aquaculture industries and has been considered as a model organism for studying intracellular and systemic infections. However, the role of type II TA systems are completely unknown in aquatic pathogenic bacteria. In this study, we identified and characterized a type II TA system, YefM-YoeB, of E. piscicida, where YefM is the antitoxin and YoeB is the toxin. yefM and yoeB are co-expressed in a bicistronic operon. When expressed in E. coli, YoeB cause bacterial growth arrest, which was restored by the addition of YefM. To investigate the biological role of the TA system, two markerless yoeB and yefM-yoeB in-frame mutant strains, TX01ΔyoeB and TX01ΔyefM-yoeB, were constructed, respectively. Compared to the wild strain TX01, TX01ΔyefM-yoeB exhibited markedly reduced resistance against oxidative stress and antibiotic, and markedly reduced ability to form persistent bacteria. The deletion of yefM-yoeB enhanced the bacterial ability of high temperature tolerance, biofilm formation, and host serum resistance, which is the first study about the relationship between type II TA system and serum resistance. In vitro infection experiment showed that the inactivation of yefM-yoeB greatly enhanced bacterial capability of adhesion in host cells. Consistently, in vivo experiment suggested that the yefM-yoeB mutation had an obvious positive effect on bacteria dissemination of fish tissues and general virulence. Introduction of a trans-expressed yefM-yoeB restored the virulence of TX01ΔyefM-yoeB. These findings suggest that YefM-YoeB is involved in responding adverse circumstance and pathogenicity of E. piscicida. In addition, we found that YefM-YoeB negatively autoregulated the expression of yefM-yoeB and YefM could directly bind with own promoter. This study provides first insights into the biological activity of type II TA system YefM-YoeB in aquatic pathogenic bacteria and contributes to understand the pathogenesis of E. piscicida.
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Affiliation(s)
- Dongmei Ma
- College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, China.,Institute of Tropical Bioscience and Biotechnology, Hainan Academy of Tropical Agricultural Resource, CATAS, Haikou, China
| | - Hanjie Gu
- Institute of Tropical Bioscience and Biotechnology, Hainan Academy of Tropical Agricultural Resource, CATAS, Haikou, China
| | - Yanjie Shi
- Institute of Tropical Bioscience and Biotechnology, Hainan Academy of Tropical Agricultural Resource, CATAS, Haikou, China
| | - Huiqin Huang
- Institute of Tropical Bioscience and Biotechnology, Hainan Academy of Tropical Agricultural Resource, CATAS, Haikou, China
| | - Dongmei Sun
- College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Yonghua Hu
- Institute of Tropical Bioscience and Biotechnology, Hainan Academy of Tropical Agricultural Resource, CATAS, Haikou, China.,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China.,Hainan Provincial Key Laboratory for Functional Components Research and Utilization of Marine Bio-resources, Haikou, China
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