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Ramatla T, Khasapane NG, Mlangeni LN, Mokgokong P, Ramaili T, Ndou R, Nkhebenyane JS, Lekota K, Thekisoe O. Detection of Salmonella Pathogenicity Islands and Antimicrobial-Resistant Genes in Salmonella enterica Serovars Enteritidis and Typhimurium Isolated from Broiler Chickens. Antibiotics (Basel) 2024; 13:458. [PMID: 38786186 PMCID: PMC11117945 DOI: 10.3390/antibiotics13050458] [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: 04/16/2024] [Revised: 05/06/2024] [Accepted: 05/14/2024] [Indexed: 05/25/2024] Open
Abstract
Rapid growth in commercial poultry production is one of the major sources of Salmonella infections that leads to human salmonellosis. The two main Salmonella enterica serovars associated with human salmonellosis are enteritidis and typhimurium. The aim of this study was to determine the prevalence of S. enterica serovars Enteritidis and S. Typhimurium as well as their Salmonella pathogenicity islands (SPI) and antibiotic resistance profiles in broiler chicken feces from slaughterhouses. A total of 480 fecal samples from broiler chickens that were grouped into 96 pooled samples were identified to have Salmonella spp. using the invA gene, whilst the Spy and sdfI genes were used to screen for the presence of S. Enteritidis and S. Typhimurium serovars, respectively, by polymerase chain reaction (PCR) assays. The isolates were also screened for the presence of Salmonella pathogenicity islands (SPIs) using PCR. The disc diffusion assay was performed to determine the antibiotic resistance profiles of the isolates. A total of 36 isolates were confirmed as Salmonella spp. through amplification of the invA gene. Out of 36 confirmed Salmonella spp. a total of 22 isolates were classified as S. Enteritidis (n = 8) and were S. Typhimurium (n = 14) serovars. All (n = 22) S. Enteritidis and S. Typhimurium isolates possessed the hilA (SPI-1), ssrB (SPI-2) and pagC (SPI-11) pathogenicity islands genes. Amongst these serovars, 50% of the isolates (n = 11/22) were resistant to tetracycline and nalidixic acid. Only 22% of the isolates, S. Typhimurium (13.6%) and S. Enteritidis (9.1%) demonstrated resistance against three or more antibiotic classes. The most detected antibiotic resistance genes were tet(K), mcr-1, sulI and strA with 13 (59.1%), 9 (40.9%), 9 (40.9%) and 7 (31.8%), respectively. The findings of this study revealed that S. Typhimurium is the most prevalent serotype detected in chicken feces. To reduce the risk to human health posed by salmonellosis, a stringent public health and food safety policy is required.
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Affiliation(s)
- Tsepo Ramatla
- Centre for Applied Food Safety and Biotechnology, Department of Life Sciences, Central University of Technology, 1 Park Road, Bloemfontein 9300, South Africa; (T.R.); (J.S.N.)
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2531, South Africa; (L.N.M.); (P.M.); (R.N.); (K.L.); (O.T.)
| | - Ntelekwane G. Khasapane
- Centre for Applied Food Safety and Biotechnology, Department of Life Sciences, Central University of Technology, 1 Park Road, Bloemfontein 9300, South Africa; (T.R.); (J.S.N.)
| | - Lungile N. Mlangeni
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2531, South Africa; (L.N.M.); (P.M.); (R.N.); (K.L.); (O.T.)
| | - Prudent Mokgokong
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2531, South Africa; (L.N.M.); (P.M.); (R.N.); (K.L.); (O.T.)
| | - Taole Ramaili
- Department of Animal Health, School of Agriculture, North-West University, Mmabatho 2735, South Africa;
| | - Rendani Ndou
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2531, South Africa; (L.N.M.); (P.M.); (R.N.); (K.L.); (O.T.)
| | - Jane S. Nkhebenyane
- Centre for Applied Food Safety and Biotechnology, Department of Life Sciences, Central University of Technology, 1 Park Road, Bloemfontein 9300, South Africa; (T.R.); (J.S.N.)
| | - Kgaugelo Lekota
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2531, South Africa; (L.N.M.); (P.M.); (R.N.); (K.L.); (O.T.)
| | - Oriel Thekisoe
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2531, South Africa; (L.N.M.); (P.M.); (R.N.); (K.L.); (O.T.)
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Chu Y, Wang D, Hao W, Sun R, Sun J, Liu Y, Liao X. Prevalence, antibiotic resistance, virulence genes and molecular characteristics of Salmonella isolated from ducks and wild geese in China. Food Microbiol 2024; 118:104423. [PMID: 38049277 DOI: 10.1016/j.fm.2023.104423] [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: 09/25/2023] [Revised: 11/01/2023] [Accepted: 11/03/2023] [Indexed: 12/06/2023]
Abstract
Salmonella is a major foodborne pathogen and the cause of significant morbidity and mortality via consumption of contaminated meat and meat-products. The prevalence of Salmonella in ducks and wild geese in China are poorly characterized and these sources represent a potential pool that could be transferred to farm-reared fowl. In this study, we isolated 335 (18.3%) Salmonella from 1830 samples and identified 24 serotypes and most prevalent were Salmonella Indiana, Salmonella Kentucky and Salmonella Typhimurium. Whole genome sequencing revealed the presence of the dominant sequence types ST17, ST198 and ST19 for these three serotypes, respectively. In addition, these isolates were most likely clonally spread across different regions while S. Kentucky also crossed the species barrier. The majority of the Salmonella isolates possessed β-lactam and fluoroquinolone resistance and these were consistent with antibiotic resistance gene profiles. We also identified 8 plasmid replicon types and all isolates possessed virulence genes and the numbers were greatest for S. Enteritidis and S. Typhimurium isolates. This study provides novel insights concerning the epidemiology of Salmonella in ducks and wild geese and provides basic data for public health screening and management.
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Affiliation(s)
- Ying Chu
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China; Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China; Animal Infectious Diseases Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Dong Wang
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China; Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China
| | - Weihua Hao
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China; Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China
| | - Ruanyang Sun
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China; Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China
| | - Jian Sun
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China; Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Yahong Liu
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China; Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Xiaoping Liao
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China; Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China.
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Toh YH, Lin GH. Roles of DJ41_1407 and DJ41_1408 in Acinetobacter baumannii ATCC19606 Virulence and Antibiotic Response. Int J Mol Sci 2024; 25:3862. [PMID: 38612672 PMCID: PMC11011904 DOI: 10.3390/ijms25073862] [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: 02/15/2024] [Revised: 03/26/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
Acinetobacter baumannii is a major cause of nosocomial infections, and its highly adaptive nature and broad range of antibiotic resistance enable it to persist in hospital environments. A. baumannii often employs two-component systems (TCSs) to regulate adaptive responses and virulence-related traits. This study describes a previously uncharacterized TCS in the A. baumannii ATCC19606 strain, consisting of a transcriptional sensor, DJ41_1407, and its regulator, DJ41_1408, located adjacent to GacA of the GacSA TCS. Markerless mutagenesis was performed to construct DJ41_1407 and DJ41_1408 single and double mutants. DJ41_1408 was found to upregulate 49 genes and downregulate 43 genes, most of which were associated with carbon metabolism and other metabolic pathways, such as benzoate degradation. MEME analysis revealed a putative binding box for DJ41_1408, 5'TGTAAATRATTAYCAWTWAT3'. Colony size, motility, biofilm-forming ability, virulence, and antibiotic resistance of DJ41_1407 and DJ41_1408 single and double mutant strains were assessed against wild type. DJ41_1407 was found to enhance motility, while DJ41_1408 was found to upregulate biofilm-forming ability, and may also modulate antibiotic response. Both DJ41_1407 and DJ41_1408 suppressed virulence, based on results from a G. mellonella infection assay. These results showcase a novel A. baumannii TCS involved in metabolism, with effects on motility, biofilm-forming ability, virulence, and antibiotic response.
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Affiliation(s)
- Yee-Huan Toh
- Master Program in Biomedical Sciences, School of Medicine, Tzu Chi University, Hualien 970374, Taiwan;
| | - Guang-Huey Lin
- Department of Microbiology and Immunology, School of Medicine, Tzu Chi University, Hualien 970374, Taiwan
- International College, Tzu Chi University, Hualien 970374, Taiwan
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Escobar-Salom M, Barceló IM, Jordana-Lluch E, Torrens G, Oliver A, Juan C. Bacterial virulence regulation through soluble peptidoglycan fragments sensing and response: knowledge gaps and therapeutic potential. FEMS Microbiol Rev 2023; 47:fuad010. [PMID: 36893807 PMCID: PMC10039701 DOI: 10.1093/femsre/fuad010] [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: 06/17/2022] [Revised: 02/10/2023] [Accepted: 03/07/2023] [Indexed: 03/11/2023] Open
Abstract
Given the growing clinical-epidemiological threat posed by the phenomenon of antibiotic resistance, new therapeutic options are urgently needed, especially against top nosocomial pathogens such as those within the ESKAPE group. In this scenario, research is pushed to explore therapeutic alternatives and, among these, those oriented toward reducing bacterial pathogenic power could pose encouraging options. However, the first step in developing these antivirulence weapons is to find weak points in the bacterial biology to be attacked with the goal of dampening pathogenesis. In this regard, during the last decades some studies have directly/indirectly suggested that certain soluble peptidoglycan-derived fragments display virulence-regulatory capacities, likely through similar mechanisms to those followed to regulate the production of several β-lactamases: binding to specific transcriptional regulators and/or sensing/activation of two-component systems. These data suggest the existence of intra- and also intercellular peptidoglycan-derived signaling capable of impacting bacterial behavior, and hence likely exploitable from the therapeutic perspective. Using the well-known phenomenon of peptidoglycan metabolism-linked β-lactamase regulation as a starting point, we gather and integrate the studies connecting soluble peptidoglycan sensing with fitness/virulence regulation in Gram-negatives, dissecting the gaps in current knowledge that need filling to enable potential therapeutic strategy development, a topic which is also finally discussed.
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Affiliation(s)
- María Escobar-Salom
- Research Unit and Microbiology Department, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Crtra. Valldemossa 79, 07010 Palma, Spain
- Centro de Investigación Biomédica en Red, Enfermedades Infecciosas (CIBERINFEC). Av. Monforte de Lemos 3-5, 28029, Madrid, Spain
| | - Isabel María Barceló
- Research Unit and Microbiology Department, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Crtra. Valldemossa 79, 07010 Palma, Spain
- Centro de Investigación Biomédica en Red, Enfermedades Infecciosas (CIBERINFEC). Av. Monforte de Lemos 3-5, 28029, Madrid, Spain
| | - Elena Jordana-Lluch
- Research Unit and Microbiology Department, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Crtra. Valldemossa 79, 07010 Palma, Spain
| | - Gabriel Torrens
- Research Unit and Microbiology Department, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Crtra. Valldemossa 79, 07010 Palma, Spain
- Centro de Investigación Biomédica en Red, Enfermedades Infecciosas (CIBERINFEC). Av. Monforte de Lemos 3-5, 28029, Madrid, Spain
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University. Försörjningsvägen 2A, SE-901 87 Umeå, Sweden
| | - Antonio Oliver
- Research Unit and Microbiology Department, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Crtra. Valldemossa 79, 07010 Palma, Spain
- Centro de Investigación Biomédica en Red, Enfermedades Infecciosas (CIBERINFEC). Av. Monforte de Lemos 3-5, 28029, Madrid, Spain
| | - Carlos Juan
- Research Unit and Microbiology Department, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Crtra. Valldemossa 79, 07010 Palma, Spain
- Centro de Investigación Biomédica en Red, Enfermedades Infecciosas (CIBERINFEC). Av. Monforte de Lemos 3-5, 28029, Madrid, Spain
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Chen J, Zhou X, Tang Y, Jiang Z, Kang X, Wang J, Yue M. Characterization of two-component system CitB family in Salmonella enterica serovar Gallinarum biovar Gallinarum. Vet Microbiol 2023; 278:109659. [PMID: 36645991 DOI: 10.1016/j.vetmic.2023.109659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 12/29/2022] [Accepted: 01/06/2023] [Indexed: 01/11/2023]
Abstract
Salmonella enterica serovar Gallinarum biovar Gallinarum is an avian-adapted pathogen causing fowl typhoid and leading to enormous economic loss in the global poultry industry. Two-component systems (TCSs) are crucial for bacteria survival, virulence, sensing and responding to the environment. 23 pairs of TCSs classified into five families were found in S. Gallinarum strain 287/91, of which the CitB family contains three pairs of TCSs, namely CitA/CitB, DcuS/DcuR and DpiB/DpiA, whose functions remained unaddressed. Thus, four mutants of S. Gallinarum strain U20, ΔcitAB (Δcit), ΔdcuSR (Δdcu), ΔdpiBA (Δdpi) and ΔcitABΔdcuSRΔdpiBA (Δ3), were constructed. The results suggested that the CitB family did not affect the growth or the metabolic capacities tested, while different TCSs exerted various effects on biofilm formation and antimicrobial resistance against multiple drug classes. Furthermore, the CitB family negatively impacted the tolerance of environmental stress, contributing to compromised virulence in chicken embryos and in vivo survival of S. Gallinarum. Collectively, this research provided new knowledge of how the CitB family is involved in the pathogenicity of S. Gallinarum.
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Affiliation(s)
- Jiaqi Chen
- Institute of Preventive Veterinary Sciences & Department of Veterinary Medicine, Zhejiang University College of Animal Sciences, Hangzhou 310058, China; Hainan Institute of Zhejiang University, Sanya 572025, China.
| | - Xiao Zhou
- Institute of Preventive Veterinary Sciences & Department of Veterinary Medicine, Zhejiang University College of Animal Sciences, Hangzhou 310058, China.
| | - Yanting Tang
- Institute of Preventive Veterinary Sciences & Department of Veterinary Medicine, Zhejiang University College of Animal Sciences, Hangzhou 310058, China.
| | - Zhijie Jiang
- Institute of Preventive Veterinary Sciences & Department of Veterinary Medicine, Zhejiang University College of Animal Sciences, Hangzhou 310058, China.
| | - Xiamei Kang
- Institute of Preventive Veterinary Sciences & Department of Veterinary Medicine, Zhejiang University College of Animal Sciences, Hangzhou 310058, China.
| | - Jianfeng Wang
- Hangzhou Original Breeding Farm, Hangzhou 311115, Zhejiang, China.
| | - Min Yue
- Institute of Preventive Veterinary Sciences & Department of Veterinary Medicine, Zhejiang University College of Animal Sciences, Hangzhou 310058, China; Hainan Institute of Zhejiang University, Sanya 572025, China; Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou 310058, China; State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, National Medical Center for Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China.
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Cho THS, Pick K, Raivio TL. Bacterial envelope stress responses: Essential adaptors and attractive targets. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119387. [PMID: 36336206 DOI: 10.1016/j.bbamcr.2022.119387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 10/05/2022] [Accepted: 10/20/2022] [Indexed: 11/06/2022]
Abstract
Millions of deaths a year across the globe are linked to antimicrobial resistant infections. The need to develop new treatments and repurpose of existing antibiotics grows more pressing as the growing antimicrobial resistance pandemic advances. In this review article, we propose that envelope stress responses, the signaling pathways bacteria use to recognize and adapt to damage to the most vulnerable outer compartments of the microbial cell, are attractive targets. Envelope stress responses (ESRs) support colonization and infection by responding to a plethora of toxic envelope stresses encountered throughout the body; they have been co-opted into virulence networks where they work like global positioning systems to coordinate adhesion, invasion, microbial warfare, and biofilm formation. We highlight progress in the development of therapeutic strategies that target ESR signaling proteins and adaptive networks and posit that further characterization of the molecular mechanisms governing these essential niche adaptation machineries will be important for sparking new therapeutic approaches aimed at short-circuiting bacterial adaptation.
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Affiliation(s)
- Timothy H S Cho
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Kat Pick
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Tracy L Raivio
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada.
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León-Montes N, Nava-Galeana J, Rodríguez-Valverde D, Soria-Bustos J, Rosales-Reyes R, Rivera-Gutiérrez S, Hirakawa H, Ares MA, Bustamante VH, De la Cruz MA. The Two-Component System CpxRA Represses Salmonella Pathogenicity Island 2 by Directly Acting on the ssrAB Regulatory Operon. Microbiol Spectr 2022; 10:e0271022. [PMID: 36073960 PMCID: PMC9603713 DOI: 10.1128/spectrum.02710-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 08/15/2022] [Indexed: 01/04/2023] Open
Abstract
The acquisition of Salmonella pathogenicity island 2 (SPI-2) conferred on Salmonella the ability to survive and replicate within host cells. The ssrAB bicistronic operon, located in SPI-2, encodes the SsrAB two-component system (TCS), which is the central positive regulator that induces the expression of SPI-2 genes as well as other genes located outside this island. On the other hand, CpxRA is a two-component system that regulates expression of virulence genes in many bacteria in response to different stimuli that perturb the cell envelope. We previously reported that the CpxRA system represses the expression of SPI-1 and SPI-2 genes under SPI-1-inducing conditions by decreasing the stability of the SPI-1 regulator HilD. Here, we show that under SPI-2-inducing conditions, which mimic the intracellular environment, CpxRA represses the expression of SPI-2 genes by the direct action of phosphorylated CpxR (CpxR-P) on the ssrAB regulatory operon. CpxR-P recognized two sites located proximal and distal from the promoter located upstream of ssrA. Consistently, we found that CpxRA reduces the replication of Salmonella enterica serovar Typhimurium inside murine macrophages. Therefore, our results reveal CpxRA as an additional regulator involved in the intracellular lifestyle of Salmonella, which in turn adds a new layer to the intricate regulatory network controlling the expression of Salmonella virulence genes. IMPORTANCE SPI-2 encodes a type III secretion system (T3SS) that is a hallmark for the species Salmonella enterica, which is essential for the survival and replication within macrophages. Expression of SPI-2 genes is positively controlled by the two-component system SsrAB. Here, we determined a regulatory mechanism involved in controlling the overgrowth of Salmonella inside macrophages. In this mechanism, CpxRA, a two-component system that is activated by extracytoplasmic stress, directly represses expression of the ssrAB regulatory operon; as a consequence, expression of SsrAB target genes is decreased. Our findings reveal a novel mechanism involved in the intracellular lifestyle of Salmonella, which is expected to sense perturbations in the bacterial envelope that Salmonella faces inside host cells, as the synthesis of the T3SS-2 itself.
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Affiliation(s)
- 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
| | - Jessica Nava-Galeana
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - 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
| | - 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
| | - Roberto Rosales-Reyes
- Unidad de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Sandra Rivera-Gutiérrez
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Hidetada Hirakawa
- Department of Bacteriology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - 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
| | - Víctor H. Bustamante
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, 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
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Kang X, Zhou X, Tang Y, Jiang Z, Chen J, Mohsin M, Yue M. Characterization of Two-Component System CitB Family in Salmonella Pullorum. Int J Mol Sci 2022; 23:ijms231710201. [PMID: 36077599 PMCID: PMC9456408 DOI: 10.3390/ijms231710201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/29/2022] [Accepted: 09/02/2022] [Indexed: 11/16/2022] Open
Abstract
Salmonella enterica, serovar Gallinarum, biovar Pullorum, is an avian-specific pathogen which has caused considerable economic losses to the poultry industry worldwide. Two-component systems (TCSs) play an essential role in obtaining nutrients, detecting the presence of neighboring bacteria and regulating the expression of virulence factors. The genome analysis of S. Pullorum strain S06004 suggesting the carriage of 22 pairs of TCSs, which belong to five families named CitB, OmpR, NarL, Chemotaxis and LuxR. In the CitB family, three pairs of TCSs, namely CitA-CitB, DcuS-DcuR and DpiB-DpiA, remain unaddressed in S. Pullorum. To systematically investigate the function of the CitB family in S. Pullorum, four mutants, ΔcitAB (abbreviated as Δcit), ΔdcuSR (Δdcu), ΔdpiBA (Δdpi) and ΔcitABΔdcuSRΔdpiBA (Δ3), were made using the CRISPR/Cas9 system. The results demonstrated that the CitB family did not affect the growth of bacteria, the results of biochemical tests, invasion and proliferation in chicken macrophage HD-11 cells and the expression of fimbrial protein. But the mutants showed thicker biofilm formation, higher resistance to antimicrobial agents, enhanced tolerance to inhibition by egg albumen and increased virulence in chicken embryos. Moreover, the deletion of Dpi TCS was detrimental to survival after exposure to hyperosmotic and oxidative environments, as well as the long-term colonization of the small intestine of chickens. Collectively, we provided new knowledge regarding the possible role of the CitB family involved in the pathogenic processes of S. Pullorum.
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Affiliation(s)
- Xiamei Kang
- Institute of Preventive Veterinary Sciences, Department of Veterinary Medicine, Zhejiang University College of Animal Sciences, Hangzhou 310058, China
| | - Xiao Zhou
- Institute of Preventive Veterinary Sciences, Department of Veterinary Medicine, Zhejiang University College of Animal Sciences, Hangzhou 310058, China
| | - Yanting Tang
- Institute of Preventive Veterinary Sciences, Department of Veterinary Medicine, Zhejiang University College of Animal Sciences, Hangzhou 310058, China
| | - Zhijie Jiang
- Institute of Preventive Veterinary Sciences, Department of Veterinary Medicine, Zhejiang University College of Animal Sciences, Hangzhou 310058, China
| | - Jiaqi Chen
- Institute of Preventive Veterinary Sciences, Department of Veterinary Medicine, Zhejiang University College of Animal Sciences, Hangzhou 310058, China
| | - Muhammad Mohsin
- Institute of Preventive Veterinary Sciences, Department of Veterinary Medicine, Zhejiang University College of Animal Sciences, Hangzhou 310058, China
| | - Min Yue
- Institute of Preventive Veterinary Sciences, Department of Veterinary Medicine, Zhejiang University College of Animal Sciences, Hangzhou 310058, China
- Hainan Institute, Zhejiang University, Sanya 572025, China
- Zhejiang Provincial Key Laboratory, Preventive Veterinary Medicine, Hangzhou 310058, China
- Correspondence: ; Tel./Fax: +86-571-88982832
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Gelalcha BD, Brown SM, Crocker HE, Agga GE, Kerro Dego O. Regulation Mechanisms of Virulence Genes in Enterohemorrhagic Escherichia coli. Foodborne Pathog Dis 2022; 19:598-612. [PMID: 35921067 DOI: 10.1089/fpd.2021.0103] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) is one of the most common E. coli pathotypes reported to cause several outbreaks of foodborne illnesses. EHEC is a zoonotic pathogen, and ruminants, especially cattle, are considered important reservoirs for the most common EHEC serotype, E. coli O157:H7. Humans are infected indirectly through the consumption of food (milk, meat, leafy vegetables, and fruits) and water contaminated by animal feces or direct contact with carrier animals or humans. E. coli O157:H7 is one of the most frequently reported causes of foodborne illnesses in developed countries. It employs two essential virulence mechanisms to trigger damage to the host. These are the development of attaching and effacing (AE) phenotypes on the intestinal mucosa of the host and the production of Shiga toxin (Stx) that causes hemorrhagic colitis and hemolytic uremic syndrome. The AE phenotype is controlled by the pathogenicity island, the locus of enterocyte effacement (LEE). The induction of both AE and Stx is under strict and highly complex regulatory mechanisms. Thus, a good understanding of these mechanisms, major proteins expressed, and environmental cues involved in the regulation of the expression of the virulence genes is vital to finding a method to control the colonization of reservoir hosts, especially cattle, and disease development in humans. This review is a concise account of the current state of knowledge of virulence gene regulation in the LEE-positive EHEC.
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Affiliation(s)
- Benti D Gelalcha
- Department of Animal Science, The University of Tennessee Institute of Agriculture, Knoxville, Tennessee, USA
| | - Selina M Brown
- Department of Animal Science, The University of Tennessee Institute of Agriculture, Knoxville, Tennessee, USA
| | - Hannah E Crocker
- Department of Animal Science, The University of Tennessee Institute of Agriculture, Knoxville, Tennessee, USA
| | - Getahun E Agga
- Food Animal Environmental Systems Research Unit, Agricultural Research Service, United States Department of Agriculture, Bowling Green, Kentucky, USA
| | - Oudessa Kerro Dego
- Department of Animal Science, The University of Tennessee Institute of Agriculture, Knoxville, Tennessee, USA
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10
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Qiu S, Jia S, Zhang F, Liu X, Ran T, Wang W, Wang C, Xu D. Two component system CpxR/A regulates the prodigiosin biosynthesis by negative control in Serratia marcescens FS14. Biochem Biophys Res Commun 2021; 579:136-140. [PMID: 34600298 DOI: 10.1016/j.bbrc.2021.09.050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Accepted: 09/20/2021] [Indexed: 11/30/2022]
Abstract
Prodigiosin is a tripyrrole red secondary metabolite synthesized by many microorganisms, including Serratia marcescens. In this study, we found that the deletion of the gene of sensor kinase CpxA dramatically decreased the prodigiosin production, while the deletion of the gene of the response regulator CpxR or both genes of CpxRA has no effect on prodigiosin production, the kinase function of CpxA is not essential for its regulation on prodigiosin production while the phosphorylation site of CpxR is required. We further demonstrated that the CpxA regulates the prodigiosin biosynthesis at the transcriptional level and the phosphatase activity of CpxA plays vital roles in the regulation of prodigiosin biosynthesis. Finally, we proposed that CpxR/A regulates the prodigiosin biosynthesis by negative control and the phosphorylation level of CpxR may determine the positive or negative control of the genes it regulated.
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Affiliation(s)
- Shenshen Qiu
- Laboratory of Microbiological Engineering of Agricultural Environment of Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Shanshan Jia
- Laboratory of Microbiological Engineering of Agricultural Environment of Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Fan Zhang
- Laboratory of Microbiological Engineering of Agricultural Environment of Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Xia Liu
- Laboratory of Microbiological Engineering of Agricultural Environment of Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Tingting Ran
- Laboratory of Microbiological Engineering of Agricultural Environment of Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Weiwu Wang
- Laboratory of Microbiological Engineering of Agricultural Environment of Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China.
| | - Changlin Wang
- Institute of Chinese Medicinal Materials, Nanjing Agricultural University, Nanjing, China.
| | - Dongqing Xu
- Laboratory of Microbiological Engineering of Agricultural Environment of Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China.
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11
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Cappable-Seq Reveals Specific Patterns of Metabolism and Virulence for Salmonella Typhimurium Intracellular Survival within Acanthamoeba castellanii. Int J Mol Sci 2021; 22:ijms22169077. [PMID: 34445780 PMCID: PMC8396566 DOI: 10.3390/ijms22169077] [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: 04/28/2021] [Revised: 08/16/2021] [Accepted: 08/19/2021] [Indexed: 01/21/2023] Open
Abstract
The bacterial pathogen Salmonella enterica, which causes enteritis, has a broad host range and extensive environmental longevity. In water and soil, Salmonella interacts with protozoa and multiplies inside their phagosomes. Although this relationship resembles that between Salmonella and mammalian phagocytes, the interaction mechanisms and bacterial genes involved are unclear. Here, we characterized global gene expression patterns of S. enterica serovar Typhimurium within Acanthamoeba castellanii at the early stage of infection by Cappable-Seq. Gene expression features of S. Typhimurium within A. castellanii were presented with downregulation of glycolysis-related, and upregulation of glyoxylate cycle-related genes. Expression of Salmonella Pathogenicity Island-1 (SPI-1), chemotaxis system, and flagellar apparatus genes was upregulated. Furthermore, expression of genes mediating oxidative stress response and iron uptake was upregulated within A. castellanii as well as within mammalian phagocytes. Hence, global S. Typhimurium gene expression patterns within A. castellanii help better understand the molecular mechanisms of Salmonella adaptation to an amoeba cell and intracellular persistence in protozoa inhabiting water and soil ecosystems.
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12
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Pérez-Morales D, Nava-Galeana J, Rosales-Reyes R, Teehan P, Yakhnin H, Melchy-Pérez EI, Rosenstein Y, De la Cruz MA, Babitzke P, Bustamante VH. An incoherent feedforward loop formed by SirA/BarA, HilE and HilD is involved in controlling the growth cost of virulence factor expression by Salmonella Typhimurium. PLoS Pathog 2021; 17:e1009630. [PMID: 34048498 PMCID: PMC8192010 DOI: 10.1371/journal.ppat.1009630] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 06/10/2021] [Accepted: 05/10/2021] [Indexed: 12/02/2022] Open
Abstract
An intricate regulatory network controls the expression of Salmonella virulence genes. The transcriptional regulator HilD plays a central role in this network by controlling the expression of tens of genes mainly required for intestinal colonization. Accordingly, the expression/activity of HilD is highly regulated by multiple factors, such as the SirA/BarA two-component system and the Hcp-like protein HilE. SirA/BarA positively regulates translation of hilD mRNA through a regulatory cascade involving the small RNAs CsrB and CsrC, and the RNA-binding protein CsrA, whereas HilE inhibits HilD activity by protein-protein interaction. In this study, we show that SirA/BarA also positively regulates translation of hilE mRNA through the same mentioned regulatory cascade. Thus, our results reveal a paradoxical regulation exerted by SirA/BarA-Csr on HilD, which involves simultaneous opposite effects, direct positive control and indirect negative control through HilE. This kind of regulation is called an incoherent type-1 feedforward loop (I1-FFL), which is a motif present in certain regulatory networks and represents a complex biological problem to decipher. Interestingly, our results, together with those from a previous study, indicate that HilE, the repressor component of the I1-FFL reported here (I1-FFLSirA/BarA-HilE-HilD), is required to reduce the growth cost imposed by the expression of the genes regulated by HilD. Moreover, we and others found that HilE is necessary for successful intestinal colonization by Salmonella. Thus, these findings support that I1-FFLSirA/BarA-HilE-HilD cooperates to control the precise amount and activity of HilD, for an appropriate balance between the growth cost and the virulence benefit generated by the expression of the genes induced by this regulator. I1-FFLSirA/BarA-HilE-HilD represents a complex regulatory I1-FFL that involves multiple regulators acting at distinct levels of gene expression, as well as showing different connections to the rest of the regulatory network governing Salmonella virulence. To infect the intestine of a broad range of hosts, including humans, Salmonella is required to express a large number of genes encoding different cellular functions, which imposes a growth penalty. Thus, Salmonella has developed complex regulatory mechanisms that control the expression of virulence genes. Here we identified a novel and sophisticated regulatory mechanism that is involved in the fine-tuned control of the expression level and activity of the transcriptional regulator HilD, for the appropriate balance between the growth cost and the virulence benefit generated by the expression of tens of Salmonella genes. This mechanism forms an incoherent type-1 feedforward loop (I1-FFL), which involves paradoxical regulation; that is, a regulatory factor exerting simultaneous opposite control (positive and negative) on another factor. I1-FFLs are present in regulatory networks of diverse organisms, from bacteria to humans, and represent a complex biological problem to decipher. Interestingly, the I1-FFL reported here is integrated by ancestral regulators and by regulators that Salmonella has acquired during evolution. Thus, our findings reveal a novel I1-FFL of bacteria, which is involved in virulence. Moreover, our results illustrate the integration of ancestral and acquired factors into a regulatory motif, which can lead to the expansion of regulatory networks.
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Affiliation(s)
- Deyanira Pérez-Morales
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
- Consejo Nacional de Ciencia y Tecnología, Ciudad de México, México
| | - Jessica Nava-Galeana
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Roberto Rosales-Reyes
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Paige Teehan
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Helen Yakhnin
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Erika I. Melchy-Pérez
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Yvonne Rosenstein
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - 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, Ciudad de México, México
| | - Paul Babitzke
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Víctor H. Bustamante
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
- * E-mail:
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13
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Gu D, Xue H, Yuan X, Yu J, Xu X, Huang Y, Li M, Zhai X, Pan Z, Zhang Y, Jiao X. Genome-Wide Identification of Genes Involved in Acid Stress Resistance of Salmonella Derby. Genes (Basel) 2021; 12:genes12040476. [PMID: 33806186 PMCID: PMC8065570 DOI: 10.3390/genes12040476] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 03/23/2021] [Accepted: 03/23/2021] [Indexed: 02/05/2023] Open
Abstract
Resistance to and survival under acidic conditions are critical for Salmonella to infect the host. As one of the most prevalent serotypes identified in pigs and humans, how S. Derby overcomes acid stress remains unclear. Here, we de novo sequenced the genome of a representative S. Derby strain 14T from our S. Derby strain stock and identified its acid resistance-associated genes using Tn-seq analysis. A total of 35 genes, including those belonging to two-component systems (TCS) (cpxAR), the CRISPR-Cas system (casCE), and other systems, were identified as essential for 14T to survive under acid stress. The results demonstrated that the growth curve and survival ability of ΔcpxA and ΔcpxR were decreased under acid stress, and the adhesion and invasion abilities to the mouse colon cancer epithelial cells (MC38) of ΔcpxR were also decreased compared with the wild type strain, suggesting that the TCS CpxAR plays an essential role in the acid resistance and virulence of S. Derby. Also, CasC and CasE were found to be responsible for acid resistance in S. Derby. Our results indicate that acid stress induces multiple genes’ expression to mediate the acid resistance of S. Derby and enhance its pathogenesis during an infection.
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Affiliation(s)
- Dan Gu
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Han Xue
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Xiaohui Yuan
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Jinyan Yu
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Xiaomeng Xu
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Yu Huang
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Mingzhu Li
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Xianyue Zhai
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Zhiming Pan
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Yunzeng Zhang
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
- Correspondence:
| | - Xinan Jiao
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
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14
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de Pina LC, da Silva FSH, Galvão TC, Pauer H, Ferreira RBR, Antunes LCM. The role of two-component regulatory systems in environmental sensing and virulence in Salmonella. Crit Rev Microbiol 2021; 47:397-434. [PMID: 33751923 DOI: 10.1080/1040841x.2021.1895067] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Adaptation to environments with constant fluctuations imposes challenges that are only overcome with sophisticated strategies that allow bacteria to perceive environmental conditions and develop an appropriate response. The gastrointestinal environment is a complex ecosystem that is home to trillions of microorganisms. Termed microbiota, this microbial ensemble plays important roles in host health and provides colonization resistance against pathogens, although pathogens have evolved strategies to circumvent this barrier. Among the strategies used by bacteria to monitor their environment, one of the most important are the sensing and signalling machineries of two-component systems (TCSs), which play relevant roles in the behaviour of all bacteria. Salmonella enterica is no exception, and here we present our current understanding of how this important human pathogen uses TCSs as an integral part of its lifestyle. We describe important aspects of these systems, such as the stimuli and responses involved, the processes regulated, and their roles in virulence. We also dissect the genomic organization of histidine kinases and response regulators, as well as the input and output domains for each TCS. Lastly, we explore how these systems may be promising targets for the development of antivirulence therapeutics to combat antibiotic-resistant infections.
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Affiliation(s)
- Lucindo Cardoso de Pina
- Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.,Programa de Pós-Graduação em Biociências, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil.,Programa de Pós-Graduação Ciência para o Desenvolvimento, Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | | | - Teca Calcagno Galvão
- Laboratório de Genômica Funcional e Bioinformática, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Heidi Pauer
- Centro de Desenvolvimento Tecnológico em Saúde, Fundação Oswaldo Cruz, Instituto Nacional de Ciência e Tecnologia de Inovação em Doenças de Populações Negligenciadas, Rio de Janeiro, Brazil
| | | | - L Caetano M Antunes
- Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.,Centro de Desenvolvimento Tecnológico em Saúde, Fundação Oswaldo Cruz, Instituto Nacional de Ciência e Tecnologia de Inovação em Doenças de Populações Negligenciadas, Rio de Janeiro, Brazil.,Laboratório de Pesquisa em Infecção Hospitalar, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
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15
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Jing W, Liu J, Wu S, Li X, Liu Y. Role of cpxA Mutations in the Resistance to Aminoglycosides and β-Lactams in Salmonella enterica serovar Typhimurium. Front Microbiol 2021; 12:604079. [PMID: 33613478 PMCID: PMC7889517 DOI: 10.3389/fmicb.2021.604079] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 01/12/2021] [Indexed: 11/13/2022] Open
Abstract
Although it has been reported that deletion of the response regulator, CpxR, in the CpxRA system confers sensitivity to aminoglycosides (AGAs) and β-lactams in Salmonella enterica serovar Typhimurium, the regulatory effects of CpxA on multidrug resistance (MDR) are yet to be fully investigated in this organism. Here, to explore the role of CpxA in MDR, various cpxA mutants including a null mutant (JSΔcpxA), a site-directed mutant (JSΔcpxA 38) and an internal in-frame deletion mutant (JSΔcpxA92 - 104 ) of the S. enterica serovar Typhimurium strain JS, were constructed. It was revealed that cpxA and cpxR deletion mutants have opposing roles in the regulation of resistance to AGAs and β-lactams. Amikacin and cefuroxime can activate the CpxRA system, which results in increased resistance of the wild-type compared with the cpxR deletion mutant. All the cpxA mutations significantly increased resistance to AGAs and β-lactams due to CpxRA system activation via the phosphorylation of CpxR. Moreover, AckA-Pta-dependent activation of CpxR increased the antibiotic resistance of cpxA deletion mutants. Further research revealed that the AcrAB-TolC conferred resistance to some AGAs and β-lactams but does not influence the regulation of resistance by CpxRA against these antibiotics. The detection of candidate MDR-related CpxR regulons revealed that the mRNA expression levels of spy, ycca, ppia, htpX, stm3031, and acrD were upregulated and that of ompW was downregulated in various cpxA mutants. Furthermore, the expression levels of nuoA and sdhC mRNAs were downregulated only in JSΔcpxA92 - 104 . These results suggested that cpxA mutations contribute to AGAs and β-lactams resistance, which is dependent on CpxR.
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Affiliation(s)
- Wenxian Jing
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Juan Liu
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Shanshan Wu
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Xuerui Li
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Yongsheng Liu
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
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16
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Romero-González LE, Pérez-Morales D, Cortés-Avalos D, Vázquez-Guerrero E, Paredes-Hernández DA, Estrada-de los Santos P, Villa-Tanaca L, De la Cruz MA, Bustamante VH, Ibarra JA. The Salmonella Typhimurium InvF-SicA complex is necessary for the transcription of sopB in the absence of the repressor H-NS. PLoS One 2020; 15:e0240617. [PMID: 33119619 PMCID: PMC7595419 DOI: 10.1371/journal.pone.0240617] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 09/21/2020] [Indexed: 12/25/2022] Open
Abstract
Expression of virulence factors in non-typhoidal Salmonella enterica depends on a wide variety of general and specific transcriptional factors that act in response to multiple environmental signals. Expression of genes for cellular invasion located in the Salmonella pathogenicity island 1 (SPI-1) is tightly regulated by several transcriptional regulators arrayed in a cascade, while repression of this system is exerted mainly by H-NS. In SPI-1, H-NS represses the expression mainly by binding to the regulatory region of hilA and derepression is exercised mainly by HilD. However, the possible regulatory role of H-NS in genes downstream from HilD and HilA, such as those regulated by InvF, has not been fully explored. Here the role of H-NS on the expression of sopB, an InvF dependent gene encoded in SPI-5, was evaluated. Our data show that InvF is required for the expression of sopB even in the absence of H-NS. Furthermore, in agreement with previous results on other InvF-regulated genes, we found that the expression of sopB requires the InvF/SicA complex. Our results support that SicA is not required for DNA binding nor for increasing affinity of InvF to DNA in vitro. Moreover, by using a bacterial two-hybrid system we were able to identify interactions between SicA and InvF. Lastly, protein-protein interaction assays suggest that InvF functions as a monomer. Derived from these results we postulate that the InvF/SicA complex does not act on sopB as an anti-H-NS factor; instead, it seems to induce the expression of sopB by acting as a classical transcriptional regulator.
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Affiliation(s)
- Luis E. Romero-González
- Laboratorio de Genética Microbiana, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
| | - Deyanira Pérez-Morales
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Daniel Cortés-Avalos
- Laboratorio de Genética Microbiana, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
| | - Edwin Vázquez-Guerrero
- Laboratorio de Genética Microbiana, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
| | - Denisse A. Paredes-Hernández
- Laboratorio de Genética Microbiana, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
| | - Paulina Estrada-de los Santos
- Laboratorio de Genética Microbiana, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
| | - Lourdes Villa-Tanaca
- Laboratorio de Genética Microbiana, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
| | - Miguel A. De la Cruz
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarías, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Víctor H. Bustamante
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - J. Antonio Ibarra
- Laboratorio de Genética Microbiana, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
- * E-mail: ,
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17
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Murret-Labarthe C, Kerhoas M, Dufresne K, Daigle F. New Roles for Two-Component System Response Regulators of Salmonella enterica Serovar Typhi during Host Cell Interactions. Microorganisms 2020; 8:microorganisms8050722. [PMID: 32413972 PMCID: PMC7285189 DOI: 10.3390/microorganisms8050722] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 05/04/2020] [Accepted: 05/09/2020] [Indexed: 12/12/2022] Open
Abstract
In order to survive external stresses, bacteria need to adapt quickly to changes in their environment. One adaptive mechanism is to coordinate and alter their gene expression by using two-component systems (TCS). TCS are composed of a sensor kinase that activates a transcriptional response regulator by phosphorylation. TCS are involved in motility, virulence, nutrient acquisition, and envelope stress in many bacteria. The pathogenic bacteria Salmonella enterica serovar Typhi (S. Typhi) possess 30 TCSs, is specific to humans, and causes typhoid fever. Here, we have individually deleted each of the 30 response regulators. We have determined their role during interaction with host cells (epithelial cells and macrophages). Deletion of most of the systems (24 out of 30) resulted in a significant change during infection. We have identified 32 new phenotypes associated with TCS of S. Typhi. Some previously known phenotypes associated with TCSs in Salmonella were also confirmed. We have also uncovered phenotypic divergence between Salmonella serovars, as distinct phenotypes between S. Typhi and S. Typhimurium were identified for cpxR. This finding highlights the importance of specifically studying S. Typhi to understand its pathogenesis mechanisms and to develop strategies to potentially reduce typhoid infections.
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18
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Staes I, Passaris I, Cambré A, Aertsen A. Population heterogeneity tactics as driving force in Salmonella virulence and survival. Food Res Int 2019; 125:108560. [DOI: 10.1016/j.foodres.2019.108560] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 07/05/2019] [Accepted: 07/12/2019] [Indexed: 01/28/2023]
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19
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Hews CL, Cho T, Rowley G, Raivio TL. Maintaining Integrity Under Stress: Envelope Stress Response Regulation of Pathogenesis in Gram-Negative Bacteria. Front Cell Infect Microbiol 2019; 9:313. [PMID: 31552196 PMCID: PMC6737893 DOI: 10.3389/fcimb.2019.00313] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 08/19/2019] [Indexed: 12/20/2022] Open
Abstract
The Gram-negative bacterial envelope is an essential interface between the intracellular and harsh extracellular environment. Envelope stress responses (ESRs) are crucial to the maintenance of this barrier and function to detect and respond to perturbations in the envelope, caused by environmental stresses. Pathogenic bacteria are exposed to an array of challenging and stressful conditions during their lifecycle and, in particular, during infection of a host. As such, maintenance of envelope homeostasis is essential to their ability to successfully cause infection. This review will discuss our current understanding of the σE- and Cpx-regulated ESRs, with a specific focus on their role in the virulence of a number of model pathogens.
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Affiliation(s)
- Claire L Hews
- School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
| | - Timothy Cho
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Gary Rowley
- School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
| | - Tracy L Raivio
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
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20
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Ares MA, Abundes-Gallegos J, Rodríguez-Valverde D, Panunzi LG, Jiménez-Galicia C, Jarillo-Quijada MD, Cedillo ML, Alcántar-Curiel MD, Torres J, Girón JA, De la Cruz MA. The Coli Surface Antigen CS3 of Enterotoxigenic Escherichia coli Is Differentially Regulated by H-NS, CRP, and CpxRA Global Regulators. Front Microbiol 2019; 10:1685. [PMID: 31417507 PMCID: PMC6681793 DOI: 10.3389/fmicb.2019.01685] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 07/09/2019] [Indexed: 12/16/2022] Open
Abstract
Enterotoxigenic Escherichia coli produces a myriad of adhesive structures collectively named colonization factors (CFs). CS3 is a CF, which is assembled into fine wiry fibrillae encoded by the cstA-H gene cluster. In this work we evaluated the influence of environmental cues such as temperature, osmolarity, pH, and carbon source on the expression of CS3 genes. The transcription of cstH major pilin gene was stimulated by growth of the bacteria in colonization factor broth at 37°C; the presence of glycerol enhanced cstH transcription, while glucose at high concentration, high osmolarity, and the depletion of divalent cations such as calcium and magnesium repressed cstH expression. In addition, we studied the role of H-NS, CpxRA, and CRP global regulators in CS3 gene expression. H-NS and CpxRA acted as repressors and CRP as an activator of cstH expression. Under high osmolarity, H-NS, and CpxRA were required for cstH repression. CS3 was required for both, bacterial adherence to epithelial cells and biofilm formation. Our data strengthens the existence of a multi-factorial regulatory network that controls transcription of CS3 genes in which global regulators, under the influence of environmental signals, control the production of this important intestinal colonization factor.
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Affiliation(s)
- 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
| | - Judith Abundes-Gallegos
- 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
| | - 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
| | - Leonardo G Panunzi
- Institut Pasteur, Biodiversity and Epidemiology of Bacterial Pathogens, Paris, France
| | - César Jiménez-Galicia
- Unidad Médica de Alta Especialidad, Laboratorio Clínico, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | - Ma Dolores Jarillo-Quijada
- Unidad de Investigacioìn en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - María Lilia Cedillo
- Centro de Detección Biomolecular, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Marìa D Alcántar-Curiel
- Unidad de Investigacioìn en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Javier Torres
- 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
| | - 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
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21
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Yi Z, Wang D, Xin S, Zhou D, Li T, Tian M, Qi J, Ding C, Wang S, Yu S. The CpxR regulates type VI secretion system 2 expression and facilitates the interbacterial competition activity and virulence of avian pathogenic Escherichia coli. Vet Res 2019; 50:40. [PMID: 31126325 PMCID: PMC6534853 DOI: 10.1186/s13567-019-0658-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 05/08/2019] [Indexed: 11/18/2022] Open
Abstract
Systemic infections caused by avian pathogenic Escherichia coli (APEC) are economically devastating to poultry industries worldwide and are also potentially threatening to human health. Pathogens must be able to precisely modulate gene expression to facilitate their survival and the successful infection. The Cpx two-component signal transduction system (TCS) regulates surface structure assembly and virulence factors implicated in Gram-negative bacterial pathogenesis. However, the roles of the Cpx TCS in bacterial fitness and pathogenesis during APEC infection are not completely understood. Here, we show that the Cpx TCS response regulator CpxR is critical to the survival and virulence of APEC. Inactivation of cpxR leads to significant defects in the interbacterial competition activity, invasion and survival of APEC in vitro and in vivo. Moreover, activation of CpxR positive regulates the expression of the APEC type VI secretion system 2 (T6SS2). Further investigations revealed that phosphorylated CpxR directly bound to the T6SS2 hcp2B promoter region. Taken together, our results demonstrated that CpxR contributes to the pathogensis of APEC at least through directly regulating the expression and function of T6SS2. This study broadens understanding of the regulatory effect of Cpx TCS, thus elucidating the mechanisms through which Cpx TCS involved in bacterial virulence.
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Affiliation(s)
- Zhengfei Yi
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Dong Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Suhua Xin
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Dongliang Zhou
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Tao Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Mingxing Tian
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Jingjing Qi
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Chan Ding
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Shaohui Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China.
| | - Shengqing Yu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China.
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22
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Transcriptional Sequencing Uncovers Survival Mechanisms of Salmonella enterica Serovar Enteritidis in Antibacterial Egg White. mSphere 2019; 4:4/1/e00700-18. [PMID: 30760616 PMCID: PMC6374596 DOI: 10.1128/msphere.00700-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Salmonella enterica serovar Enteritidis is a major foodborne pathogen that causes salmonellosis mainly through contaminated chicken eggs or egg products and has been a worldwide public health threat since 1980. Frequent outbreaks of this serotype through eggs correlate significantly with its exceptional survival ability in the antibacterial egg white. Research on the survival mechanism of S. Enteritidis in egg white will help to further understand the complex and highly effective antibacterial mechanisms of egg white and lay the foundation for the development of safe and effective vaccines to prevent egg contamination by this Salmonella serotype. Key pathways and genes that were previously overlooked under bactericidal conditions were characterized as being induced in egg white, and synergistic effects between different antimicrobial factors appear to exist according to the gene expression changes. Our work provides new insights into the survival mechanism of S. Enteritidis in egg white. The survival mechanism of Salmonella enterica serovar Enteritidis in antibacterial egg white is not fully understood. In our lab, an egg white-resistant strain, S. Enteritidis SJTUF 10978, was identified. Cell envelope damage and osmotic stress response (separation of cell wall and inner membrane as well as cytoplasmic shrinkage) of this strain surviving in egg white were identified through microscopic observation. RNA-Seq analysis of the transcriptome of Salmonella survival in egg white showed that a considerable number of genes involved in DNA damage repair, alkaline pH adaptation, osmotic stress adaptation, envelope damage repair, Salmonella pathogenicity island 2 (SPI-2), iron absorption, and biotin synthesis were significantly upregulated (fold change ≥ 2) in egg white, indicating that these pathways or genes might be critical for bacterial survival. RNA-Seq results were confirmed by qRT-PCR, and the survival analysis of six gene deletion mutants confirmed their importance in the survival of bacteria in egg white. The importance of alkaline pH adaptation and envelope damage repair for Salmonella to survive in egg white were further confirmed by analysis of nhaA, cpxR, waaH, and eco deletion mutants. According to the RNA-Seq results, we propose that alkaline pH adaptation might be the cause of bacterial osmotic stress phenotype and that the synergistic effect between alkaline pH and other inhibitory factors can enhance the bacteriostatic effect of egg white. Moreover, cpxR and sigE were recognized as the central regulators that coordinate bacterial metabolism to adapt to envelope damage and alkaline pH. IMPORTANCESalmonella enterica serovar Enteritidis is a major foodborne pathogen that causes salmonellosis mainly through contaminated chicken eggs or egg products and has been a worldwide public health threat since 1980. Frequent outbreaks of this serotype through eggs correlate significantly with its exceptional survival ability in the antibacterial egg white. Research on the survival mechanism of S. Enteritidis in egg white will help to further understand the complex and highly effective antibacterial mechanisms of egg white and lay the foundation for the development of safe and effective vaccines to prevent egg contamination by this Salmonella serotype. Key pathways and genes that were previously overlooked under bactericidal conditions were characterized as being induced in egg white, and synergistic effects between different antimicrobial factors appear to exist according to the gene expression changes. Our work provides new insights into the survival mechanism of S. Enteritidis in egg white.
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23
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Raja I, Kumar V, Sabapathy H, Kumariah M, Rajendran K, Tennyson J. Prediction and identification of novel sRNAs involved in Agrobacterium strains by integrated genome-wide and transcriptome-based methods. FEMS Microbiol Lett 2018; 365:5127044. [PMID: 30307512 DOI: 10.1093/femsle/fny247] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 10/10/2018] [Indexed: 01/23/2023] Open
Abstract
Small RNAs (sRNAs) are a class of gene regulators in bacteria, playing a central role in their response to environmental changes. Bioinformatic prediction facilitates the identification of sRNAs expressed under different conditions. We propose a novel method of prediction of sRNAs from the genome of Agrobacterium based on a positional weight matrix of conditional sigma factors. sRNAs predicted from the genome are integrated with the virulence-specific transcriptome data to identify putative sRNAs that are overexpressed during Agrobacterial virulence induction. A total of 384 sRNAs are predicted from transcriptome data analysis of Agrobacterium fabrum and 100-500 sRNAs from the genome of different Agrobacterial strains. In order to refine our study, a final set of 10 novel sRNAs with best features across different replicons targeting virulence genes were experimentally identified using semi-quantitative polymerase chain reaction. Since Ti plasmid plays a major role in virulence, out of 10 sRNAs across the replicons, 4 novel sRNAs differentially expressed under virulence induced and non-induced conditions are predicted to be present in the Ti plasmid T-DNA region flanking virulence-related genes like agrocinopine synthase, indole 3-lactate synthase, mannopine synthase and tryptophan monooxygenase. Further validation of the function of these sRNAs in conferring virulence would be relevant to explore their role in Agrobacterium-mediated plant transformation.
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Affiliation(s)
- Ilamathi Raja
- Department of Plant Sciences, School of Biological Sciences, Madurai Kamaraj University, Madurai-625 021, Tamil Nadu, India
| | - Vikram Kumar
- Department of Biotechnology, National Centre for Cell Science, Pune-411007, Maharashtra, India
| | - Hariharan Sabapathy
- DBT-IPLS Program, School of Biological Sciences, Madurai Kamaraj University, Madurai-625 021, Tamil Nadu, India
| | - Manoharan Kumariah
- Department of Plant Sciences, School of Biological Sciences, Madurai Kamaraj University, Madurai-625 021, Tamil Nadu, India
| | - Kasthuri Rajendran
- Department of Plant Sciences, School of Biological Sciences, Madurai Kamaraj University, Madurai-625 021, Tamil Nadu, India
| | - Jebasingh Tennyson
- Department of Plant Sciences, School of Biological Sciences, Madurai Kamaraj University, Madurai-625 021, Tamil Nadu, India
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24
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Dean CR, Barkan DT, Bermingham A, Blais J, Casey F, Casarez A, Colvin R, Fuller J, Jones AK, Li C, Lopez S, Metzger LE, Mostafavi M, Prathapam R, Rasper D, Reck F, Ruzin A, Shaul J, Shen X, Simmons RL, Skewes-Cox P, Takeoka KT, Tamrakar P, Uehara T, Wei JR. Mode of Action of the Monobactam LYS228 and Mechanisms Decreasing In Vitro Susceptibility in Escherichia coli and Klebsiella pneumoniae. Antimicrob Agents Chemother 2018; 62:e01200-18. [PMID: 30061293 PMCID: PMC6153799 DOI: 10.1128/aac.01200-18] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 07/25/2018] [Indexed: 12/14/2022] Open
Abstract
The monobactam scaffold is attractive for the development of new agents to treat infections caused by drug-resistant Gram-negative bacteria because it is stable to metallo-β-lactamases (MBLs). However, the clinically used monobactam aztreonam lacks stability to serine β-lactamases (SBLs) that are often coexpressed with MBLs. LYS228 is stable to MBLs and most SBLs. LYS228 bound purified Escherichia coli penicillin binding protein 3 (PBP3) similarly to aztreonam (derived acylation rate/equilibrium dissociation constant [k2/Kd ] of 367,504 s-1 M-1 and 409,229 s-1 M-1, respectively) according to stopped-flow fluorimetry. A gel-based assay showed that LYS228 bound mainly to E. coli PBP3, with weaker binding to PBP1a and PBP1b. Exposing E. coli cells to LYS228 caused filamentation consistent with impaired cell division. No single-step mutants were selected from 12 Enterobacteriaceae strains expressing different classes of β-lactamases at 8× the MIC of LYS228 (frequency, <2.5 × 10-9). At 4× the MIC, mutants were selected from 2 of 12 strains at frequencies of 1.8 × 10-7 and 4.2 × 10-9 LYS228 MICs were ≤2 μg/ml against all mutants. These frequencies compared favorably to those for meropenem and tigecycline. Mutations decreasing LYS228 susceptibility occurred in ramR and cpxA (Klebsiella pneumoniae) and baeS (E. coli and K. pneumoniae). Susceptibility of E. coli ATCC 25922 to LYS228 decreased 256-fold (MIC, 0.125 to 32 μg/ml) after 20 serial passages. Mutants accumulated mutations in ftsI (encoding the target, PBP3), baeR, acrD, envZ, sucB, and rfaI These results support the continued development of LYS228, which is currently undergoing phase II clinical trials for complicated intraabdominal infection and complicated urinary tract infection (registered at ClinicalTrials.gov under identifiers NCT03377426 and NCT03354754).
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Affiliation(s)
- Charles R Dean
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - David T Barkan
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Alun Bermingham
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Johanne Blais
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Fergal Casey
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Anthony Casarez
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Richard Colvin
- Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - John Fuller
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Adriana K Jones
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Cindy Li
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Sara Lopez
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Louis E Metzger
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Mina Mostafavi
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Ramadevi Prathapam
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Dita Rasper
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Folkert Reck
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Alexey Ruzin
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Jacob Shaul
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Xiaoyu Shen
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Robert L Simmons
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Peter Skewes-Cox
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Kenneth T Takeoka
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Pramila Tamrakar
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Tsuyoshi Uehara
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
| | - Jun-Rong Wei
- Novartis Institutes for BioMedical Research, Emeryville, California, USA
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25
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Matter LB, Ares MA, Abundes-Gallegos J, Cedillo ML, Yáñez JA, Martínez-Laguna Y, De la Cruz MA, Girón JA. The CpxRA stress response system regulates virulence features of avian pathogenic Escherichia coli. Environ Microbiol 2018; 20:3363-3377. [PMID: 30062827 DOI: 10.1111/1462-2920.14368] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 07/27/2018] [Indexed: 12/29/2022]
Abstract
Avian pathogenic Escherichia coli (APEC) causes localized and systemic avian infections and is responsible for considerable economic losses in the poultry industry. This organism adheres and invades human and avian cells, however, the regulatory networks that dictate its virulence are largely unknown. The CpxRA two-component system is responsible for sensing and controlling outer-membrane stress and detecting misfolded proteins in the bacterial periplasmic space. CpxA is a membrane sensor kinase and CpxR is a cytoplasmic transcriptional regulator. In this study, we found that the CpxRA system regulates the virulence properties of APEC. Adherence, invasiveness, motility, production of type 1 fimbriae and biofilm were negatively affected in the ΔcpxA mutant indicating that the CpxA is required for full manifestation of these phenotypes. We also found that CpxR-P directly bound to the fimA promoter, locking the fimS region of type 1 fimbriae in the phase-OFF orientation. In addition, the absence of CpxA also reduced flagella production strongly suggesting that CpxRA regulates these two important surface organelles in APEC. This study provides compelling evidence of the role of the CpxRA two-component system in the regulation of virulence factors of avian pathogenic E. coli.
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Affiliation(s)
- Letícia B Matter
- Emerging Pathogens Institute, University of Florida, P.O. Box 100009, 2055 Mowry Road, Gainesville, FL, USA.,Departamento de Ciências da Saúde, Universidade Regional Integrada do Alto Uruguai e das Missões, Rua Universidade das Missões, CEP: 98.802-470, Santo Ângelo, Rio Grande do Sul, Brasil
| | - Miguel A Ares
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Centro Médico Nacional Siglo XXI, Instituto Mexicano de Seguro Social, Ciudad de México, México
| | - Judith Abundes-Gallegos
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Centro Médico Nacional Siglo XXI, Instituto Mexicano de Seguro Social, Ciudad de México, México
| | - María L Cedillo
- Centro de Detección Biomolecular, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Jorge A Yáñez
- Facultad de Estomatología, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Ygnacio Martínez-Laguna
- Centro de Investigaciones en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Miguel A De la Cruz
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Centro Médico Nacional Siglo XXI, Instituto Mexicano de Seguro Social, Ciudad de México, México
| | - Jorge A Girón
- Centro de Detección Biomolecular, Benemérita Universidad Autónoma de Puebla, Puebla, México
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Salmonella enterica Serovar Typhimurium CpxRA Two-Component System Contributes to Gut Colonization in Salmonella-Induced Colitis. Infect Immun 2018; 86:IAI.00280-18. [PMID: 29685984 DOI: 10.1128/iai.00280-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 04/12/2018] [Indexed: 12/13/2022] Open
Abstract
Salmonella enterica, a common cause of diarrhea, has to colonize the gut lumen to elicit disease. In the gut, the pathogen encounters a vast array of environmental stresses that cause perturbations in the bacterial envelope. The CpxRA two-component system monitors envelope perturbations and responds by altering the bacterial gene expression profile. This allows Salmonella to survive under such harmful conditions. Therefore, CpxRA activation is likely to contribute to Salmonella gut infection. However, the role of the CpxRA-mediated envelope stress response in Salmonella-induced diarrhea is unclear. Here, we show that CpxRA is dispensable for the induction of colitis by S. enterica serovar Typhimurium, whereas it is required for gut colonization. We prove that CpxRA is expressed during gut infection and that the presence of antimicrobial peptides in growth media activates the expression of CpxRA-regulated genes. In addition, we demonstrate that a S Typhimurium strain lacking the cpxRA gene is able to cause colitis but is unable to continuously colonize the gut. Finally, we show that CpxRA-dependent gut colonization requires the host gut inflammatory response, while DegP, a CpxRA-regulated protease, is dispensable. Our findings reveal that the CpxRA-mediated envelope stress response plays a crucial role in Salmonella gut infection, suggesting that CpxRA might be a promising therapeutic target for infectious diarrhea.
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Troxell B. A type 6 secretion system (T6SS) encoded gene within Salmonella enterica serovar Enteritidis contributes to virulence. Virulence 2018; 9:585-587. [PMID: 29380670 PMCID: PMC7000193 DOI: 10.1080/21505594.2017.1421829] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Bacteria interact with their host through protein secretion systems and surface structures. Pathogenic bacteria encode protein secretion systems that promote the invasion of the host's tissue, the evasion of the host's immune response, the thwarting microbial competitors, and ultimately survival within the host. For motile bacteria, the presence of extracellular flagella provides the host with a structural motif used for activation of the immune system. Within this issue of Virulence, the article "Identification of a novel gene in ROD9 island of Salmonella Enteritidis involved in the alteration of virulence-associated protein expression" describes the contribution of a gene, SEN1005, toward host-pathogen interaction. The authors demonstrate the contribution of SEN1005 to cell culture bioassays and infection in a mouse model of colitis. In each tested scenario, deletion of SEN1005 results in a phenotypic defect that was complemented by providing the SEN1005 gene in trans. SEN1005 contributes to the expression of known virulence factors within SPI-1, flagellar and chemotaxis genes, and heat shock/chaperone genes. Although much work is needed to fully elucidate the function of SEN1005, this work contributes toward our understanding of the genetic factors used by Salmonella to cause foodborne illnesses.
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Affiliation(s)
- Bryan Troxell
- a Alcami Corporation, Biotechnology department , Durham , North Carolina , USA
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HilE Regulates HilD by Blocking DNA Binding in Salmonella enterica Serovar Typhimurium. J Bacteriol 2018; 200:JB.00750-17. [PMID: 29378886 DOI: 10.1128/jb.00750-17] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 01/18/2018] [Indexed: 11/20/2022] Open
Abstract
The Salmonella type three secretion system (T3SS), encoded in the Salmonella pathogenicity island 1 (SPI1) locus, mediates the invasion of the host intestinal epithelium. SPI1 expression is dependent upon three AraC-like regulators: HilD, HilC, and RtsA. These regulators act in a complex feed-forward loop to activate each other and hilA, which encodes the activator of the T3SS structural genes. HilD has been shown to be the major integration point of most signals known to activate the expression of the SPI1 T3SS, acting as a switch to control induction of the system. HilE is a negative regulator that acts upon HilD. Here we provide genetic and biochemical data showing that HilE specifically binds to HilD but not to HilC or RtsA. This protein-protein interaction blocks the ability of HilD to bind DNA as shown by both an in vivo reporter system and an in vitro gel shift assay. HilE does not affect HilD dimerization, nor does it control the stability of the HilD protein. We also investigated the role of HilE during the infection of mice using competition assays. Although deletion of hilE does not confer a phenotype, the hilE mutation does suppress the invasion defect conferred by loss of FliZ, which acts as a positive signal controlling HilD protein activity. Together, these data suggest that HilE functions to restrict low-level HilD activity, preventing premature activation of SPI1 until positive inputs reach a threshold required to fully induce the system.IMPORTANCESalmonella is a leading cause of gastrointestinal and systemic disease throughout the world. The SPI1 T3SS is required for Salmonella to induce inflammatory diarrhea and to gain access to underlying tissue. A complex regulatory network controls expression of SPI1 in response to numerous physiological inputs. Most of these signals impinge primarily on HilD translation or activity. The system is triggered when HilD activity crosses a threshold that allows efficient activation of its own promoter. This threshold is set by HilE, which binds to HilD to prevent the inevitable minor fluctuations in HilD activity from inappropriately activating the system. The circuit also serves as a paradigm for systems that must integrate numerous environmental parameters to control regulatory output.
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Paredes-Amaya CC, Valdés-García G, Juárez-González VR, Rudiño-Piñera E, Bustamante VH. The Hcp-like protein HilE inhibits homodimerization and DNA binding of the virulence-associated transcriptional regulator HilD in Salmonella. J Biol Chem 2018. [PMID: 29535187 DOI: 10.1074/jbc.ra117.001421] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
HilD is an AraC-like transcriptional regulator that plays a central role in Salmonella virulence. HilD controls the expression of the genes within the Salmonella pathogenicity island 1 (SPI-1) and of several genes located outside SPI-1, which are mainly required for Salmonella invasion of host cells. The expression, amount, and activity of HilD are tightly controlled by the activities of several factors. The HilE protein represses the expression of the SPI-1 genes through its interaction with HilD; however, the mechanism by which HilE affects HilD is unknown. In this study, we used genetic and biochemical assays revealing how HilE controls the transcriptional activity of HilD. We found that HilD needs to assemble in homodimers to induce expression of its target genes. Our results further indicated that HilE individually interacts with each the central and the C-terminal HilD regions, mediating dimerization and DNA binding, respectively. We also observed that these interactions consistently inhibit HilD dimerization and DNA binding. Interestingly, a computational analysis revealed that HilE shares sequence and structural similarities with Hcp proteins, which act as structural components of type 6 secretion systems in Gram-negative bacteria. In conclusion, our results uncover the molecular mechanism by which the Hcp-like protein HilE controls dimerization and DNA binding of the virulence-promoting transcriptional regulator HilD. Our findings may indicate that HilE's activity represents a functional adaptation during the evolution of Salmonella pathogenicity.
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Affiliation(s)
| | - Gilberto Valdés-García
- Molecular Medicine and Bioprocesses, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - Víctor R Juárez-González
- Molecular Medicine and Bioprocesses, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - Enrique Rudiño-Piñera
- Molecular Medicine and Bioprocesses, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
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Controlled Activity of the Salmonella Invasion-Associated Injectisome Reveals Its Intracellular Role in the Cytosolic Population. mBio 2017; 8:mBio.01931-17. [PMID: 29208746 PMCID: PMC5717391 DOI: 10.1128/mbio.01931-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The Salmonella invasion-associated type III secretion system (T3SS1) is an essential virulence factor required for entry into nonphagocytic cells and consequent uptake into a Salmonella-containing vacuole (SCV). While Salmonella is typically regarded as a vacuolar pathogen, a subset of bacteria escape from the SCV in epithelial cells and eventually hyperreplicate in the cytosol. T3SS1 is downregulated following bacterial entry into mammalian cells, but cytosolic Salmonella cells are T3SS1 induced, suggesting prolonged or resurgent activity of T3SS1 in this population. In order to investigate the postinternalization contributions of T3SS1 to the Salmonella infectious cycle in epithelial cells, we bypassed its requirement for bacterial entry by tagging the T3SS1-energizing ATPase InvC at the C terminus with peptides that are recognized by bacterial tail-specific proteases. This caused a dramatic increase in InvC turnover which rendered even assembled injectisomes inactive. Bacterial strains conditionally expressing these unstable InvC variants were proficient for invasion but underwent rapid and sustained intracellular inactivation of T3SS1 activity when InvC expression ceased. This allowed us to directly implicate T3SS1 activity in cytosolic colonization and bacterial egress. We subsequently identified two T3SS1-delivered effectors, SopB and SipA, that are required for efficient colonization of the epithelial cell cytosol. Overall, our findings support a multifaceted, postinvasion role for T3SS1 and its effectors in defining the cytosolic population of intracellular Salmonella. A needle-like apparatus, the type III secretion system (T3SS) injectisome, is absolutely required for Salmonella enterica to enter epithelial cells; this requirement has hampered the analysis of its postentry contributions. To identify T3SS1-dependent intracellular activities, in this study we overcame this limitation by developing a conditional inactivation in the T3SS whereby T3SS activity is chemically induced during culture in liquid broth, permitting bacterial entry into epithelial cells, but is quickly and perpetually inactivated in the absence of inducer. In this sense, the mutant acts like wild-type bacteria when extracellular and as a T3SS mutant once it enters a host cell. This “conditional” mutant allowed us to directly link activity of this T3SS with nascent vacuole lysis, cytosolic proliferation, and cellular egress, demonstrating that the invasion-associated T3SS also contributes to essential intracellular stages of the S. enterica infectious cycle.
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31
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Pérez-Morales D, Banda MM, Chau NYE, Salgado H, Martínez-Flores I, Ibarra JA, Ilyas B, Coombes BK, Bustamante VH. The transcriptional regulator SsrB is involved in a molecular switch controlling virulence lifestyles of Salmonella. PLoS Pathog 2017; 13:e1006497. [PMID: 28704543 PMCID: PMC5562331 DOI: 10.1371/journal.ppat.1006497] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 08/18/2017] [Accepted: 06/28/2017] [Indexed: 11/22/2022] Open
Abstract
The evolution of bacterial pathogenicity, heavily influenced by horizontal gene transfer, provides new virulence factors and regulatory connections that alter bacterial phenotypes. Salmonella pathogenicity islands 1 and 2 (SPI-1 and SPI-2) are chromosomal regions that were acquired at different evolutionary times and are essential for Salmonella virulence. In the intestine of mammalian hosts, Salmonella expresses the SPI-1 genes that mediate its invasion to the gut epithelium. Once inside the cells, Salmonella down-regulates the SPI-1 genes and induces the expression of the SPI-2 genes, which favor its intracellular replication. The mechanism by which the invasion machinery is deactivated following successful invasion of host cells is not known. Here, we show that the SPI-2 encoded transcriptional regulator SsrB, which positively controls SPI-2, acts as a dual regulator that represses expression of SPI-1 during intracellular stages of infection. The mechanism of this SPI-1 repression by SsrB was direct and acts upon the hilD and hilA regulatory genes. The phenotypic effect of this molecular switch activity was a significant reduction in invasion ability of S. enterica serovar Typhimurium while promoting the expression of genes required for intracellular survival. During mouse infections, Salmonella mutants lacking SsrB had high levels of hilA (SPI-1) transcriptional activity whereas introducing a constitutively active SsrB led to significant hilA repression. Thus, our results reveal a novel SsrB-mediated mechanism of transcriptional crosstalk between SPI-1 and SPI-2 that helps Salmonella transition to the intracellular lifestyle. Salmonella infect humans and a wide range of mammalian hosts. Successful infection requires the bacteria to sense their surroundings and regulate gene expression in a way that maximizes fitness in that particular environment. The two major lifestyles of Salmonella include extracellular stages and intracellular stages of host cell infection; however, the molecular mechanisms of how Salmonella transitions between these two lifestyles are not completely understood. Here we show that the transcriptional regulator SsrB functions in a dual capacity, activating genes required for intracellular survival while simultaneously repressing genes needed for extracellular stages of infection. Our data highlight how regulatory crosstalk is selective during infection, presumably because it helps facilitate rapid transitions in bacterial lifestyles that ultimately promote bacterial survival and replication.
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Affiliation(s)
- Deyanira Pérez-Morales
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - María M. Banda
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - N. Y Elizabeth Chau
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Heladia Salgado
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Irma Martínez-Flores
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - J. Antonio Ibarra
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
| | - Bushra Ilyas
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Brian K. Coombes
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Víctor H. Bustamante
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
- * E-mail:
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32
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Signal transduction pathway mediated by the novel regulator LoiA for low oxygen tension induced Salmonella Typhimurium invasion. PLoS Pathog 2017; 13:e1006429. [PMID: 28575106 PMCID: PMC5476282 DOI: 10.1371/journal.ppat.1006429] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 06/19/2017] [Accepted: 05/23/2017] [Indexed: 02/03/2023] Open
Abstract
Salmonella enterica serovar Typhimurium (S. Typhimurium) is a major intestinal pathogen of both humans and animals. Salmonella pathogenicity island 1 (SPI-1)-encoded virulence genes are required for S. Typhimurium invasion. While oxygen (O2) limitation is an important signal for SPI-1 induction under host conditions, how the signal is received and integrated to the central SPI-1 regulatory system in S. Typhimurium is not clear. Here, we report a signal transduction pathway that activates SPI-1 expression in response to low O2. A novel regulator encoded within SPI-14 (STM14_1008), named LoiA (low oxygen induced factor A), directly binds to the promoter and activates transcription of hilD, leading to the activation of hilA (the master activator of SPI-1). Deletion of loiA significantly decreased the transcription of hilA, hilD and other representative SPI-1 genes (sipB, spaO, invH, prgH and invF) under low O2 conditions. The response of LoiA to the low O2 signal is mediated by the ArcB/ArcA two-component system. Deletion of either arcA or arcB significantly decreased transcription of loiA under low O2 conditions. We also confirmed that SPI-14 contributes to S. Typhimurium virulence by affecting invasion, and that loiA is the virulence determinant of SPI-14. Mice infection assays showed that S. Typhimurium virulence was severely attenuated by deletion of either the entire SPI-14 region or the single loiA gene after oral infection, while the virulence was not affected by either deletion after intraperitoneal infection. The signal transduction pathway described represents an important mechanism for S. Typhimurium to sense and respond to low O2 conditions of the host intestinal tract for invasion. SPI-14-encoded loiA is an essential element of this pathway that integrates the low O2 signal into the SPI-1 regulatory system. Acquisition of SPI-14 is therefore crucial for the evolution of S. Typhimurium as an intestinal pathogen. Salmonella enterica serovar Typhimurium (S. Typhimurium) is a major intestinal pathogen of both humans and animals. Salmonella pathogenicity island 1 (SPI-1) is required for host cell invasion by S. Typhimurium. Expression of SPI-1 genes is induced by low oxygen (O2) tension under host conditions, but the relevant regulatory mechanisms are not clear. Here, we report a low O2-induced signal transduction pathway for the activation of SPI-1 expression in S. Typhimurium. A novel regulator, STM14_1008 (named LoiA), encoded within SPI-14 directly activates hilD, which in turn activates hilA (the master activator of SPI-1), and thus other SPI-1 genes under O2-limited conditions. The response of LoiA to the low O2 signal is mediated by the ArcB/ArcA two-component system. We also confirmed that SPI-14 contributes to S. Typhimurium virulence by affecting invasion, with loiA as the virulence determinant. This novel SPI-1 activation pathway can be used by S. Typhimurium to sense and respond to low O2 conditions of the host intestinal tract for invasion. Acquisition of SPI-14 is therefore very important for the evolution of S. Typhimurium virulence by providing an essential component of this pathway, loiA.
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Martínez-Flores I, Pérez-Morales D, Sánchez-Pérez M, Paredes CC, Collado-Vides J, Salgado H, Bustamante VH. In silico clustering of Salmonella global gene expression data reveals novel genes co-regulated with the SPI-1 virulence genes through HilD. Sci Rep 2016; 6:37858. [PMID: 27886269 PMCID: PMC5122947 DOI: 10.1038/srep37858] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 11/02/2016] [Indexed: 01/04/2023] Open
Abstract
A wide variety of Salmonella enterica serovars cause intestinal and systemic infections to humans and animals. Salmonella Patogenicity Island 1 (SPI-1) is a chromosomal region containing 39 genes that have crucial virulence roles. The AraC-like transcriptional regulator HilD, encoded in SPI-1, positively controls the expression of the SPI-1 genes, as well as of several other virulence genes located outside SPI-1. In this study, we applied a clustering method to the global gene expression data of S. enterica serovar Typhimurium from the COLOMBOS database; thus genes that show an expression pattern similar to that of SPI-1 genes were selected. This analysis revealed nine novel genes that are co-expressed with SPI-1, which are located in different chromosomal regions. Expression analyses and protein-DNA interaction assays showed regulation by HilD for six of these genes: gtgE, phoH, sinR, SL1263 (lpxR) and SL4247 were regulated directly, whereas SL1896 was regulated indirectly. Interestingly, phoH is an ancestral gene conserved in most of bacteria, whereas the other genes show characteristics of genes acquired by Salmonella. A role in virulence has been previously demonstrated for gtgE, lpxR and sinR. Our results further expand the regulon of HilD and thus identify novel possible Salmonella virulence genes.
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Affiliation(s)
- Irma Martínez-Flores
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - Deyanira Pérez-Morales
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - Mishael Sánchez-Pérez
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - Claudia C Paredes
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - Julio Collado-Vides
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - Heladia Salgado
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - Víctor H Bustamante
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
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Troxell B. Salmonella enterica serovar Typhimurium utilizes the ClpPX and Lon proteases for optimal fitness in the ceca of chickens. Poult Sci 2016; 95:1617-1623. [PMID: 26994203 PMCID: PMC4957304 DOI: 10.3382/ps/pew103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 02/05/2016] [Indexed: 11/20/2022] Open
Abstract
Salmonella enterica serovar Typhimurium (S. Typhimurium) is a leading cause of salmonellosis. Poultry and poultry products are implicated in transmission of Salmonella to humans. In 2013, an outbreak of S Typhimurium occurred that comprised 39 states within the United States and was associated with backyard flocks of chickens. Colonization of the avian host by S Typhimurium requires numerous genetic factors encoded within the bacterium. Of particular interest are genetic factors induced by alternative sigma factors within S Typhimurium since these genetic elements are important for adaptation to different environmental stresses. The heat shock response is a dedicated change in gene regulation within bacteria in response to several stresses, specifically growth at 42°C. Because chickens have a higher body temperature than other animals (42°C) the hypothesis was tested that components of the heat shock response are important for optimal fitness within the chicken. To this end, deletion of the heat shock proteases clpPX (BTNC0022) or lon (BTNC0021) was accomplished and the bacterial fitness in vivo was compared to the "wild-type" strain (NC1040) using a competition assay. One-day-old chicks were orally gavaged with an equal mixture of NC1040 and either BTNC0022 or BTNC0021. Quantification of viable bacteria over time by using plate counts indicated that deletion of either heat shock protease resulted in significantly reduced colonization of the chicken ceca compared to the wild-type strain. To satisfy the molecular Koch's postulates, clpPX and lon mutants were complemented in trans using a low-copy number plasmid for additional in vivo experiments. Complementation studies confirmed the importance of either heat shock protease to colonization of the chicken ceca. This report demonstrated that both ClpPX and Lon were important for optimal fitness within chickens. Moreover, these results suggested that components of the heat shock may be critical factors used by S. Typhimurium for colonization of poultry. The use of feed additives or other treatments that inactivate or inhibit ClpPX or Lon may reduce the bacterial burden of S. Typhimurium in poultry.
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Affiliation(s)
- Bryan Troxell
- Prestage Department of Poultry Science, North Carolina State University, Raleigh 27695.
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35
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De la Cruz MA, Morgan JK, Ares MA, Yáñez-Santos JA, Riordan JT, Girón JA. The Two-Component System CpxRA Negatively Regulates the Locus of Enterocyte Effacement of Enterohemorrhagic Escherichia coli Involving σ(32) and Lon protease. Front Cell Infect Microbiol 2016; 6:11. [PMID: 26904510 PMCID: PMC4742615 DOI: 10.3389/fcimb.2016.00011] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/18/2016] [Indexed: 12/05/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) is a significant cause of serious human gastrointestinal disease worldwide. EHEC strains contain a pathogenicity island called the locus of enterocyte effacement (LEE), which encodes virulence factors responsible for damaging the gut mucosa. The Cpx envelope stress response of E. coli is controlled by a two-component system (TCS) consisting of a sensor histidine kinase (CpxA) and a cytoplasmic response regulator (CpxR). In this study, we investigated the role of CpxRA in the expression of LEE-encoded virulence factors of EHEC. We found that a mutation in cpxA significantly affected adherence of EHEC to human epithelial cells. Analysis of this mutant revealed the presence of high levels of CpxR which repressed transcription of grlA and ler, the main positive virulence regulators of the LEE, and influenced negatively the production of the type 3 secretion system–associated EspABD translocator proteins. It is known that CpxR activates rpoH (Sigma factor 32), which in turns activates transcription of the lon protease gene. We found that transcription levels of ler and grlA were significantly increased in the lon and cpxA lon mutants suggesting that lon is involved in down-regulating LEE genes. In addition, the Galleria mellonella model of infection was used to analyze the effect of the loss of the cpx and lon genes in EHEC's ability to kill the larvae. We found that the cpxA mutant was significantly deficient at killing the larvae however, the cpxA lon mutant which overexpresses LEE genes in vitro, was unable to kill the larvae, suggesting that virulence in the G. mellonella model is T3SS independent and that CpxA modulates virulence through a yet unknown EHEC-specific factor. Our data provides new insights and broadens our scope into the complex regulatory network of the LEE in which the CpxA sensor kinase plays an important role in a cascade involving both global and virulence regulators.
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Affiliation(s)
- Miguel A De la Cruz
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Centro Médico Nacional Siglo XXI-IMSSMexico City, Mexico; Emerging Pathogens Institute, University of FloridaGainesville, FL, USA
| | - Jason K Morgan
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida Tampa, FL, USA
| | - Miguel A Ares
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Centro Médico Nacional Siglo XXI-IMSS Mexico City, Mexico
| | - Jorge A Yáñez-Santos
- Facultad de Estomatología, Benemerita Universidad Autonoma de Puebla Puebla, Mexico
| | - James T Riordan
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida Tampa, FL, USA
| | - Jorge A Girón
- Emerging Pathogens Institute, University of FloridaGainesville, FL, USA; Centro de Deteccion Biomolecular, Benemerita Universidad Autonoma de PueblaPuebla, Mexico
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