1
|
Ekdahl AM, Julien T, Suraj S, Kribelbauer J, Tavazoie S, Freddolino PL, Contreras LM. Multiscale regulation of nutrient stress responses in Escherichia coli from chromatin structure to small regulatory RNAs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.20.599902. [PMID: 38979244 PMCID: PMC11230228 DOI: 10.1101/2024.06.20.599902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Recent research has indicated the presence of heterochromatin-like regions of extended protein occupancy and transcriptional silencing of bacterial genomes. We utilized an integrative approach to track chromatin structure and transcription in E. coli K-12 across a wide range of nutrient conditions. In the process, we identified multiple loci which act similarly to facultative heterochromatin in eukaryotes, normally silenced but permitting expression of genes under specific conditions. We also found a strong enrichment of small regulatory RNAs (sRNAs) among the set of differentially expressed transcripts during nutrient stress. Using a newly developed bioinformatic pipeline, the transcription factors regulating sRNA expression were bioinformatically predicted, with experimental follow-up revealing novel relationships for 36 sRNA-transcription factors candidates. Direct regulation of sRNA expression was confirmed by mutational analysis for five sRNAs of metabolic interest: IsrB, CsrB and CsrC, GcvB, and GadY. Our integrative analysis thus reveals additional layers of complexity in the nutrient stress response in E. coli and provides a framework for revealing similar poorly understood regulatory logic in other organisms.
Collapse
Affiliation(s)
- Alyssa M Ekdahl
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Tatiana Julien
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Sahana Suraj
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Judith Kribelbauer
- Department of Systems Biology, Columbia University, New York, NY, 10032, USA
| | - Saeed Tavazoie
- Department of Systems Biology, Columbia University, New York, NY, 10032, USA
| | - P Lydia Freddolino
- Department of Biological Chemistry and Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Lydia M Contreras
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| |
Collapse
|
2
|
Ma K, Chinelo OR, Gu M, Kong F, Jiang Y, Wang H, Xue T. Role of ArcA in the regulation of antibiotic sensitivity in avian pathogenic Escherichia coli. Poult Sci 2024; 103:103686. [PMID: 38574461 PMCID: PMC11004985 DOI: 10.1016/j.psj.2024.103686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 03/16/2024] [Accepted: 03/18/2024] [Indexed: 04/06/2024] Open
Abstract
Avian pathogenic Escherichia coli (APEC) is one of the common extraintestinal infectious disease pathogens in chickens, geese, and other birds, inducing serious impediments to the development of the poultry industry. Hence, investigating how bacteria regulate themselves amidst different challenging conditions is immense essential in prevention and treatment for bacterial pathogen infections. The ArcA regulatory factor has been reported to regulate oxygen availability in strains, but its role in regulation of antibiotics resistance in APEC is unclear. This study delved into understanding how ArcA regulates antibiotic resistance in APEC. An E. coli APEC40 arcA knockout strain was constructed, and the regulatory mechanism of arcA on APEC antibiotic susceptibility was identified by drug sensitivity test, colony counting assay, real-time quantitative PCR, β-galactosidase assays and electrophoretic mobility shift assay (EMSA). The results showed that ArcA directly binds to the promoter region of the outer membrane protein OmpC/OmpW and regulates bacterial susceptibility to kanamycin and penicillin G. At the same time, the double knockout of ompW and ompW/arcA resulted in an increase in resistance to kanamycin compared to the deletion of the arcA gene. This outcome provided experimental proof suggesting that the outer membrane protein OmpW could serve as a crucial pathway for the ingress of kanamycin into cells. These results confirmed the important regulatory role of ArcA transcription factors under APEC antibiotic stress.
Collapse
Affiliation(s)
- Kai Ma
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Okoro Ruth Chinelo
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Mantian Gu
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Fanwenqing Kong
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Ying Jiang
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Hui Wang
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230027, China.
| | - Ting Xue
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China.
| |
Collapse
|
3
|
Alobaidallah MSA, García V, Wellner SM, Thomsen LE, Herrero-Fresno A, Olsen JE. Enhancing the Efficacy of Chloramphenicol Therapy for Escherichia coli by Targeting the Secondary Resistome. Antibiotics (Basel) 2024; 13:73. [PMID: 38247632 PMCID: PMC10812820 DOI: 10.3390/antibiotics13010073] [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: 12/13/2023] [Revised: 01/03/2024] [Accepted: 01/09/2024] [Indexed: 01/23/2024] Open
Abstract
The increasing prevalence of antimicrobial resistance and the limited availability of new antimicrobial agents have created an urgent need for new approaches to combat these issues. One such approach involves reevaluating the use of old antibiotics to ensure their appropriate usage and maximize their effectiveness, as older antibiotics could help alleviate the burden on newer agents. An example of such an antibiotic is chloramphenicol (CHL), which is rarely used due to its hematological toxicity. In the current study, we employed a previously published transposon mutant library in MG1655/pTF2::blaCTX-M-1, containing over 315,000 unique transposon insertions, to identify the genetic factors that play an important role during growth in the presence of CHL. The list of conditionally essential genes, collectively referred to as the secondary resistome (SR), included 67 genes. To validate our findings, we conducted gene knockout experiments on six genes: arcA, hfq, acrZ, cls, mdfA, and nlpI. Deleting these genes resulted in increased susceptibility to CHL as demonstrated by MIC estimations and growth experiments, suggesting that targeting the products encoded from these genes may reduce the dose of CHL needed for treatment and hence reduce the toxicity associated with CHL treatment. Thus, the gene products are indicated as targets for antibiotic adjuvants to favor the use of CHL in modern medicine.
Collapse
Affiliation(s)
- Mosaed Saleh A. Alobaidallah
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; (M.S.A.A.); (V.G.); (S.M.W.); (L.E.T.)
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia
- King Abdullah International Medical Research Center, Jeddah 22384, Saudi Arabia
| | - Vanesa García
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; (M.S.A.A.); (V.G.); (S.M.W.); (L.E.T.)
- Laboratorio de Referencia de Escherichia coli (LREC), Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade da Santiago de Compostela (USC), 27002 Lugo, Spain
| | - Sandra M. Wellner
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; (M.S.A.A.); (V.G.); (S.M.W.); (L.E.T.)
| | - Line E. Thomsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; (M.S.A.A.); (V.G.); (S.M.W.); (L.E.T.)
| | - Ana Herrero-Fresno
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; (M.S.A.A.); (V.G.); (S.M.W.); (L.E.T.)
- Department of Biochemistry and Molecular Biology, Faculty of Sciences, Campus Terra, Universidade da Santiago de Compostela (USC), 27002 Lugo, Spain
| | - John Elmerdahl Olsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark; (M.S.A.A.); (V.G.); (S.M.W.); (L.E.T.)
| |
Collapse
|
4
|
Jiang F, Yang Y, Mao Z, Cai W, Li G. ArcA positively regulates the expression of virulence genes and contributes to virulence of porcine Shiga toxin-producing enterotoxigenic Escherichia coli. Microbiol Spectr 2023; 11:e0152523. [PMID: 37916813 PMCID: PMC10714933 DOI: 10.1128/spectrum.01525-23] [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: 04/12/2023] [Accepted: 10/09/2023] [Indexed: 11/03/2023] Open
Abstract
IMPORTANCE Enterotoxigenic Escherichia coli (ETEC) cause severe diarrhea in humans and animals, leading to death and huge economic loss worldwide. Thus, elucidation of ETEC's pathogenic mechanisms will provide powerful data for the discovery of drugs serving as prevention or therapeutics against ETEC-caused diarrheal diseases. Here, we report that ArcA plays an essential role in the pathogenicity and virulence regulation in ETEC by positively regulating the expression of several key virulence factors including F18 fimbriae, heat-labile and heat-stable toxins, Shiga toxin 2e, and hemolysin, under microaerobic conditions and in vivo. Moreover, we found that positive regulation of several virulence genes by ArcA requires a global repressor H-NS (histone-like nucleoid structuring), implying that ArcA may exert positive effects by antagonizing H-NS. Collectively, our data established a key role for ArcA in the pathogenicity of porcine ETEC and ETEC strains isolated from human infections. Moreover, our work reveals another layer of regulation in relation to oxygen control of virulence factors in ETEC.
Collapse
Affiliation(s)
- Fengwei Jiang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| | - Yan Yang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Zhao Mao
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Wentong Cai
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Ganwu Li
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| |
Collapse
|
5
|
Mao Z, Zhang H, Cai W, Yang Y, Zhang X, Jiang F, Li G. NhaA facilitates the maintenance of bacterial envelope integrity and the evasion of complement attack contributing to extraintestinal pathogenic Escherichia coli virulence. Infect Immun 2023; 91:e0003923. [PMID: 37815368 PMCID: PMC10652942 DOI: 10.1128/iai.00039-23] [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: 01/24/2023] [Accepted: 09/01/2023] [Indexed: 10/11/2023] Open
Abstract
Extraintestinal pathogenic Escherichia coli (ExPEC) is responsible for severe bloodstream infections in humans and animals. However, the mechanisms underlying ExPEC's serum resistance remain incompletely understood. Through the transposon-directed insertion-site sequencing approach, our previous study identified nhaA, the gene encoding a Na+/H+ antiporter, as a crucial factor for infection in vivo. In this study, we investigated the role of NhaA in ExPEC virulence utilizing both in vitro models and systemic infection models involving avian and mammalian animals. Genetic mutagenesis analysis revealed that nhaA deletion resulted in filamentous bacterial morphology and rendered the bacteria more susceptible to sodium dodecyl sulfate, suggesting the role of nhaA in maintaining cell envelope integrity. The nhaA mutant also displayed heightened sensitivity to complement-mediated killing compared to the wild-type strain, attributed to augmented deposition of complement components (C3b and C9). Remarkably, NhaA played a more crucial role in virulence compared to several well-known factors, including Iss, Prc, NlpI, and OmpA. Our findings revealed that NhaA significantly enhanced virulence across diverse human ExPEC prototype strains within B2 phylogroups, suggesting widespread involvement in virulence. Given its pivotal role, NhaA could serve as a potential drug target for tackling ExPEC infections.
Collapse
Affiliation(s)
- Zhao Mao
- Key Laboratory of Veterinary Public Health of Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Haobo Zhang
- National Animal Tuberculosis Reference Laboratory, Division of Zoonoses Surveillance, China Animal Health and Epidemiology Center, Qingdao, China
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| | - Wentong Cai
- Key Laboratory of Veterinary Public Health of Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Yan Yang
- Key Laboratory of Veterinary Public Health of Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Xinyang Zhang
- Key Laboratory of Veterinary Public Health of Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Fengwei Jiang
- Key Laboratory of Veterinary Public Health of Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Ganwu Li
- Key Laboratory of Veterinary Public Health of Ministry of Agriculture, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| |
Collapse
|
6
|
Tani A, Masuda S, Fujitani Y, Iga T, Haruna Y, Kikuchi S, Shuaile W, Lv H, Katayama S, Yurimoto H, Sakai Y, Kato J. Metabolism-linked methylotaxis sensors responsible for plant colonization in Methylobacterium aquaticum strain 22A. Front Microbiol 2023; 14:1258452. [PMID: 37901831 PMCID: PMC10613068 DOI: 10.3389/fmicb.2023.1258452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 10/02/2023] [Indexed: 10/31/2023] Open
Abstract
Motile bacteria take a competitive advantage in colonization of plant surfaces to establish beneficial associations that eventually support plant health. Plant exudates serve not only as primary growth substrates for bacteria but also as bacterial chemotaxis attractants. A number of plant-derived compounds and corresponding chemotaxis sensors have been documented, however, the sensors for methanol, one of the major volatile compounds released by plants, have not been identified. Methylobacterium species are ubiquitous plant surface-symbiotic, methylotrophic bacteria. A plant-growth promoting bacterium, M. aquaticum strain 22A exhibits chemotaxis toward methanol (methylotaxis). Its genome encodes 52 methyl-accepting chemotaxis proteins (MCPs), among which we identified three MCPs (methylotaxis proteins, MtpA, MtpB, and MtpC) responsible for methylotaxis. The triple gene mutant of the MCPs exhibited no methylotaxis, slower gathering to plant tissues, and less efficient colonization on plants than the wild type, suggesting that the methylotaxis mediates initiation of plant-Methylobacterium symbiosis and engages in proliferation on plants. To examine how these MCPs are operating methylotaxis, we generated multiple gene knockouts of the MCPs, and Ca2+-dependent MxaFI and lanthanide (Ln3+)-dependent XoxF methanol dehydrogenases (MDHs), whose expression is regulated by the presence of Ln3+. MtpA was found to be a cytosolic sensor that conducts formaldehyde taxis (formtaxis), as well as methylotaxis when MDHs generate formaldehyde. MtpB contained a dCache domain and exhibited differential cellular localization in response to La3+. MtpB expression was induced by La3+, and its activity required XoxF1. MtpC exhibited typical cell pole localization, required MxaFI activity, and was regulated under MxbDM that is also required for MxaF expression. Strain 22A methylotaxis is realized by three independent MCPs, two of which monitor methanol oxidation by Ln3+-regulated MDHs, and one of which monitors the common methanol oxidation product, formaldehyde. We propose that methanol metabolism-linked chemotaxis is the key factor for the efficient colonization of Methylobacterium on plants.
Collapse
Affiliation(s)
- Akio Tani
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Sachiko Masuda
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
- Japan Science and Technology Agency, Advanced Low Carbon Technology Research and Development Program (JST ALCA), Kawaguchi, Japan
| | - Yoshiko Fujitani
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Toshiki Iga
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Yuuki Haruna
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Shiho Kikuchi
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Wang Shuaile
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Haoxin Lv
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Shiori Katayama
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Hiroya Yurimoto
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Yasuyoshi Sakai
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Junichi Kato
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashihiroshima, Japan
| |
Collapse
|
7
|
Yan J, Yang B, Xue X, Li J, Li Y, Li A, Ding P, Cao B. Transcriptome Analysis Reveals the Effect of PdhR in Plesiomonas shigelloides. Int J Mol Sci 2023; 24:14473. [PMID: 37833920 PMCID: PMC10572922 DOI: 10.3390/ijms241914473] [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: 08/29/2023] [Revised: 09/19/2023] [Accepted: 09/21/2023] [Indexed: 10/15/2023] Open
Abstract
The pyruvate dehydrogenase complex regulator (PdhR) was originally identified as a repressor of the pdhR-aceEF-lpd operon, which encodes the pyruvate dehydrogenase complex (PDHc) and PdhR itself. According to previous reports, PdhR plays a regulatory role in the physiological and metabolic pathways of bacteria. At present, the function of PdhR in Plesiomonas shigelloides is still poorly understood. In this study, RNA sequencing (RNA-Seq) of the wild-type strain and the ΔpdhR mutant strains was performed for comparison to identify the PdhR-controlled pathways, revealing that PdhR regulates ~7.38% of the P. shigelloides transcriptome. We found that the deletion of pdhR resulted in the downregulation of practically all polar and lateral flagella genes in P. shigelloides; meanwhile, motility assay and transmission electron microscopy (TEM) confirmed that the ΔpdhR mutant was non-motile and lacked flagella. Moreover, the results of RNA-seq and quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) showed that PdhR positively regulated the expression of the T3SS cluster, and the ΔpdhR mutant significantly reduced the ability of P. shigelloides to infect Caco-2 cells compared with the WT. Consistent with previous research, pyruvate-sensing PdhR directly binds to its promoter and inhibits pdhR-aceEF-lpd operon expression. In addition, we identified two additional downstream genes, metR and nuoA, that are directly negatively regulated by PdhR. Furthermore, we also demonstrated that ArcA was identified as being located upstream of pdhR and lpdA and directly negatively regulating their expression. Overall, we revealed the function and regulatory pathway of PdhR, which will allow for a more in-depth investigation into P. shigelloides pathogenicity as well as the complex regulatory network.
Collapse
Affiliation(s)
- Junxiang Yan
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin 300457, China
| | - Bin Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin 300457, China
| | - Xinke Xue
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin 300457, China
| | - Jinghao Li
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin 300457, China
| | - Yuehua Li
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin 300457, China
| | - Ang Li
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300353, China
- College of Pharmacy Laboratory of Molecular Drug Research, Nankai University, Tianjin 300353, China
| | - Peng Ding
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin 300457, China
| | - Boyang Cao
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin 300457, China
| |
Collapse
|
8
|
Lyu Z, Han S, Li J, Guo Z, Geng N, Lyu C, Qin L, Li N. Epidemiological investigation and drug resistance characteristics of Riemerella anatipestifer strains from large-scale duck farms in Shandong Province, China from March 2020 to March 2022. Poult Sci 2023; 102:102759. [PMID: 37209657 PMCID: PMC10209456 DOI: 10.1016/j.psj.2023.102759] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 04/20/2023] [Accepted: 04/24/2023] [Indexed: 05/22/2023] Open
Abstract
Infectious serositis is a common disease caused by Riemerella anatipestifer (R. anatipestifer) in ducks, characterized by respiratory distress, septicemia, and neurological symptoms. In this study, 1,020 samples (brain and liver) were collected from ducks with suspected R. anatipestifer infection from March 2020 to March 2022 in Shandong Province, of which 171 R. anatipestifer strains were identified by PCR and isolation culture. The serotype of all strains was analyzed, and 74 strains were subjected to drug sensitivity tests and drug resistance genes detection. The results showed that the overall prevalence rate of R. anatipestifer in Shandong Province was 16.7% (171/1,020), with most strains coming from brain samples of ducklings under 3-mo old collected from September to December each year. Histopathological examination showed that heart vessels of the diseased duck were highly dilated and filled with red blood cells, with obvious fibrin exudates outside the pericardium, and fatty degeneration of liver cells. There were 45 strains of serotype 1, 45 strains of serotype 2, 2 strains of serotype 4, 33 strains of serotype 6, 44 strains of serotype 7, and 2 strains of serotype 10. The minimum inhibitory concentration (MIC) of 10 common antibiotics against 74 representative strains was determined by the agar dilution method. It was found that 74 strains had the most severe resistance to gentamicin (77%) and fully susceptible to ceftriaxone, but the 81.1% isolated strains were multidrug resistant. Resistance genes testing of 74 R. anatipestifers showed that tetracycline resistance gene tet X had the highest detection rate of 95.9%, followed by macrolide resistance gene ermF with 77%, and the rate of β-lactam resistance gene blaTEM is the lowest (10.8%). The animal experiment of 4 R. anatipestifer strains with different serotypes showed that they had strong pathogenicity to 7-day-old ducklings, which could cause nervous symptoms, and the mortality rate was 58% to 70%. The autopsy showed obvious pathological changes. These findings of this study on R. anatipestifer will help us to understand the latest prevalence, drug resistance characteristics, and pathogenicity of R. anatipestifer in Shandong, China, and provide a scientific guide for the treatment and control of the disease.
Collapse
Affiliation(s)
- Zehao Lyu
- College of Animal Science and Technology, Shandong Agricultural University, Tai'an City 271018, Shandong Province, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Tai'an City 271018, Shandong Province, China; Sino-German Cooperative Research Centre for Zoonosis of Animal Origin Shandong Province, Shandong Agricultural University, Tai'an City 271018, Shandong Province, China
| | - Shanshan Han
- Qingdao Key Laboratory of Livestock & Poultry Pathogen Biotechnology, Qingdao Jiazhi Biotechnology Co., Ltd., Qingdao 266100, China
| | - Jing Li
- College of Animal Science and Technology, Shandong Agricultural University, Tai'an City 271018, Shandong Province, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Tai'an City 271018, Shandong Province, China; Sino-German Cooperative Research Centre for Zoonosis of Animal Origin Shandong Province, Shandong Agricultural University, Tai'an City 271018, Shandong Province, China
| | - Zhiyun Guo
- College of Animal Science and Technology, Shandong Agricultural University, Tai'an City 271018, Shandong Province, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Tai'an City 271018, Shandong Province, China; Sino-German Cooperative Research Centre for Zoonosis of Animal Origin Shandong Province, Shandong Agricultural University, Tai'an City 271018, Shandong Province, China
| | - Ningwei Geng
- College of Animal Science and Technology, Shandong Agricultural University, Tai'an City 271018, Shandong Province, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Tai'an City 271018, Shandong Province, China; Sino-German Cooperative Research Centre for Zoonosis of Animal Origin Shandong Province, Shandong Agricultural University, Tai'an City 271018, Shandong Province, China
| | - Chuang Lyu
- Qingdao Key Laboratory of Livestock & Poultry Pathogen Biotechnology, Qingdao Jiazhi Biotechnology Co., Ltd., Qingdao 266100, China
| | - Liting Qin
- Qingdao Key Laboratory of Livestock & Poultry Pathogen Biotechnology, Qingdao Jiazhi Biotechnology Co., Ltd., Qingdao 266100, China
| | - Ning Li
- College of Animal Science and Technology, Shandong Agricultural University, Tai'an City 271018, Shandong Province, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Tai'an City 271018, Shandong Province, China; Sino-German Cooperative Research Centre for Zoonosis of Animal Origin Shandong Province, Shandong Agricultural University, Tai'an City 271018, Shandong Province, China.
| |
Collapse
|
9
|
Wang Y, Teng Y, Geng J, Long J, Yang H, Duan G, Chen S. Involvement of RNA chaperone Hfq in the regulation of antibiotic resistance and virulence in Shigella sonnei. Res Microbiol 2023:104047. [PMID: 36868486 DOI: 10.1016/j.resmic.2023.104047] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 02/21/2023] [Accepted: 02/23/2023] [Indexed: 03/05/2023]
Abstract
The host factor for RNA phage Qβ replicase (Hfq) is a crucial post-transcriptional regulator in many bacterial pathogens, facilitating the interaction between small non-coding RNAs (sRNAs) and their target mRNAs. Studies have suggested that Hfq plays a role in antibiotic resistance and virulence in bacteria, although its functions in Shigella are not fully understood. In this study, we investigated the functional roles of Hfq in Shigella sonnei (S. sonnei) by constructing an hfq deletion mutant. Our phenotypic assays showed that the hfq deletion mutant was more sensitivity to antibiotics and had impaired virulence. Transcriptome analyses supported the results concerning the phenotype of the hfq mutant and showed that differentially expressed genes were mainly enriched in the KEGG pathways two-component system, ABC transporters, ribosome, and Escherichia coli biofilm formation. Additionally, we predicted eleven novel Hfq-dependent sRNAs, which were potentially involved in the regulation of antibiotic resistance and/or virulence in S. sonnei. Our findings suggest that Hfq plays a post-transcriptional role in regulating antibiotic resistance and virulence in S. sonnei, and could provide a basis for future studies on Hfq-sRNA-mRNA regulatory networks in this important pathogen.
Collapse
Affiliation(s)
- Ya Wang
- Department of Epidemiology and Health Statistics, College of Public Health, Zhengzhou University, Zhengzhou, China
| | - Yanli Teng
- Henan Province Center for Disease Control and Prevention, Zhengzhou, China
| | - Juan Geng
- Department of Epidemiology and Health Statistics, College of Public Health, Zhengzhou University, Zhengzhou, China
| | - Jinzhao Long
- Department of Epidemiology and Health Statistics, College of Public Health, Zhengzhou University, Zhengzhou, China
| | - Haiyan Yang
- Department of Epidemiology and Health Statistics, College of Public Health, Zhengzhou University, Zhengzhou, China
| | - Guangcai Duan
- Department of Epidemiology and Health Statistics, College of Public Health, Zhengzhou University, Zhengzhou, China
| | - Shuaiyin Chen
- Department of Epidemiology and Health Statistics, College of Public Health, Zhengzhou University, Zhengzhou, China.
| |
Collapse
|
10
|
Zhang D, Xu S, Wu H, Liu J, Wang Y, Zhu G. Melatonin Is Neuroprotective in Escherichia coli Meningitis Depending on Intestinal Microbiota. Int J Mol Sci 2022; 24:ijms24010298. [PMID: 36613745 PMCID: PMC9820133 DOI: 10.3390/ijms24010298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/19/2022] [Accepted: 12/20/2022] [Indexed: 12/28/2022] Open
Abstract
Avian meningitis Escherichia coli (E. coli) can cause acute bacterial meningitis which threatens poultry health, causes great economic losses in the poultry industry, and has recently been speculated as a potential zoonotic pathogen. Melatonin can counteract bacterial meningitis-induced disruption of the blood-brain barrier (BBB), neuroinflammation, and reduce mortality. There are increasing data showing that melatonin's beneficial effects on bacterial meningitis are associated with intestinal microbiota. In this study, our data showed that melatonin alleviated neurological symptoms, enhanced survival rate, protected the integrity of the BBB, reduced the bacterial load in various tissues and blood, and inhibited inflammation and neutrophil infiltration of brain tissue in an APEC TW-XM-meningitis mice model. The results of 16S rRNA showed that melatonin pretreatment significantly maintained the composition of intestinal microbiota in APEC-meningitis mice. The abundance and diversity of intestinal microbiota were disturbed in APEC TW-XM-meningitis mice, with a decreased ratio of Firmicutes to Bacteroides and an increased the abundance of Proteobacteria. Melatonin pretreatment could significantly improve the composition and abundance of harmful bacteria and alleviate the decreased abundance of beneficial bacteria. Importantly, melatonin failed to affect the meningitis neurologic symptoms caused by APEC TW-XM infection in antibiotic-pretreated mice. In conclusion, the results suggest that melatonin can effectively prevent meningitis induced by APEC TW-XM infection in mice, depending on the intestinal microbiota. This finding is helpful to further explore the specific target mechanism of melatonin-mediated intestinal microbiota in the prevention of and protection against Escherichia coli meningitis.
Collapse
Affiliation(s)
- Dong Zhang
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Shu Xu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Hucong Wu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Jiaqi Liu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Yiting Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Guoqiang Zhu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
- Correspondence:
| |
Collapse
|
11
|
Characterization of the Role of Two-Component Systems in Antibiotic Resistance Formation in Salmonella enterica Serovar Enteritidis. mSphere 2022; 7:e0038322. [PMID: 36286534 PMCID: PMC9769886 DOI: 10.1128/msphere.00383-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The two-component system (TCS) is one of the primary pathways by which bacteria adapt to environmental stresses such as antibiotics. This study aimed to systematically explore the role of TCSs in the development of multidrug resistance (MDR) in Salmonella enterica serovar Enteritidis. Twenty-six in-frame deletion mutants of TCSs were generated from S. Enteritidis SJTUF12367 (the wild type [WT]). Antimicrobial susceptibility tests with these mutants revealed that 10 TCSs were involved in the development of antibiotic resistance in S. Enteritidis. In these 10 pairs of TCSs, functional defects in CpxAR, PhoPQ, and GlnGL in various S. Enteritidis isolates led to a frequent decrease in MIC values against at least three classes of clinically important antibiotics, including cephalosporins and quinolones, which indicated the importance of these TCSs to the formation of MDR. Interaction network analysis via STRING revealed that the genes cpxA, cpxR, phoP, and phoQ played important roles in the direct interaction with global regulatory genes and the relevant genes of efflux pumps and outer membrane porins. Quantitative reverse transcription-PCR analysis further demonstrated that the increased susceptibility to cephalosporins and quinolones in ΔphoP and ΔcpxR mutant cells was accompanied by increased expression of membrane porin genes (ompC, ompD, and ompF) and reduced expression of efflux pump genes (acrA, macB, and mdtK), as well as an adverse transcription of the global regulatory genes (ramA and crp). These results indicated that CpxAR and PhoPQ played an important role in the development of MDR in S. Enteritidis through regulation of cell membrane permeability and efflux pump activity. IMPORTANCE S. Enteritidis is a predominant Salmonella serotype that causes human salmonellosis and frequently exhibits high-level resistance to commonly used antibiotics, including cephalosporins and quinolones. Although TCSs are known as regulators for bacterial adaptation to stressful conditions, which modulates β-lactam resistance in Vibrio parahaemolyticus and colistin resistance in Salmonella enterica serovar Typhimurium, there is little knowledge of their functional mechanisms underlying the development of antibiotic resistance in S. Enteritidis. Here, we systematically identified the TCS elements in S. Enteritidis SJTUF12367, revealed that the three TCSs CpxAR, PhoPQ, and GlnGL were crucial for the MDR formation in S. Enteritidis, and preliminarily illustrated the regulatory functions of CpxAR and PhoPQ for antimicrobial resistance genes. Our work provides the basis to understand the important TCSs that regulate formation of antibiotic resistance in S. Enteritidis.
Collapse
|
12
|
Lv M, Ye S, Hu M, Xue Y, Liang Z, Zhou X, Zhang L, Zhou J. Two-component system ArcBA modulates cell motility and biofilm formation in Dickeya oryzae. FRONTIERS IN PLANT SCIENCE 2022; 13:1033192. [PMID: 36340374 PMCID: PMC9634086 DOI: 10.3389/fpls.2022.1033192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/11/2022] [Indexed: 06/16/2023]
Abstract
Phytopathogen Dickeya oryzae is a causal agent of rice foot rot disease and the pathogen has an array of virulence factors, such as phytotoxin zeamines, plant cell wall degrading enzymes, cell motility, and biofilms, collectively contributing to the bacterial pathogenesis. In this study, through deletion analysis of predicted regulatory genes in D. oryzae EC1, we identified a two-component system associated with the regulation of bacterial virulence. The two-component system contains a histidine kinase ArcB and a response regulator ArcA, and deletion of their coding genes resulted in changed phenotypes in cell motility, biofilm formation, and bacterial virulence. Electrophoretic mobility shift assay revealed that ArcA bound to the promoters of the bcs operon and bssS, which respectively encode enzymes for the synthesis of celluloses and a biofilm formation regulatory protein. ArcA could also bind to the promoters of three virulence associated transcriptional regulatory genes, i.e., fis, slyA and ohrR. Surprisingly, although these three regulators were shown to modulate the production of cell wall degrading enzymes and zeamines, deletion of arcB and arcA did not seem to affect these phenotypes. Taken together, the findings from this study unveiled a new two-component system associated with the bacterial pathogenesis, which contributes to the virulence of D. oryzae mainly through its action on bacterial motility and biofilm formation.
Collapse
Affiliation(s)
- Mingfa Lv
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Sixuan Ye
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Ming Hu
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Yang Xue
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Zhibin Liang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Xiaofan Zhou
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, Guangdong Province, China
| | - Lianhui Zhang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, Guangdong Province, China
| | - Jianuan Zhou
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| |
Collapse
|
13
|
Fu D, Wu J, Gu Y, Li Q, Shao Y, Feng H, Song X, Tu J, Qi K. The response regulator OmpR contributes to the pathogenicity of avian pathogenic Escherichia coli. Poult Sci 2022; 101:101757. [PMID: 35240350 PMCID: PMC8892008 DOI: 10.1016/j.psj.2022.101757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/23/2022] [Accepted: 01/25/2022] [Indexed: 11/03/2022] Open
Abstract
Avian colibacillosis is a serious systemic infectious disease in poultry and caused by avian pathogenic Escherichia coli (APEC). Previous studies have shown that 2-component systems (TCSs) are involved in the pathogenicity of APEC. OmpR, a response regulator of OmpR/EnvZ TCS, plays an important role in E. coli K-12. However, whether OmpR correlates with APEC pathogenesis has not been established. In this study, we constructed an ompR gene mutant and complement strains by using the CRISPR-Cas9 system and found that the inactivation of the ompR gene attenuated bacterial motility, biofilm formation, and the production of curli. The resistance to environmental stress, serum sensitivity, adhesion, and invasion of DF-1 cells, and pathogenicity in chicks were all significantly reduced in the mutant strain AE17ΔompR. These phenotypes were restored in the complement strain AE17C-ompR. The qRT-PCR results showed that OmpR influences the expression of genes associated with the flagellum, biofilm formation, and virulence. These findings indicate that the regulator OmpR contributes to APEC pathogenicity by affecting the expression and function of virulence factors.
Collapse
|
14
|
Li Y, Yan J, Guo X, Wang X, Liu F, Cao B. The global regulators ArcA and CytR collaboratively modulate Vibrio cholerae motility. BMC Microbiol 2022; 22:22. [PMID: 35021992 PMCID: PMC8753867 DOI: 10.1186/s12866-022-02435-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 01/05/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Vibrio cholerae, a Gram-negative bacterium, is highly motile owing to the presence of a single polar flagellum. The global anaerobiosis response regulator, ArcA regulates the expression of virulence factors and enhance biofilm formation in V. cholerae. However, the function of ArcA for the motility of V. cholerae is yet to be elucidated. CytR, which represses nucleoside uptake and catabolism, is known to play a chief role in V. cholerae pathogenesis and flagellar synthesis but the mechanism that CytR influences motility is unclear.
Results
In this study, we found that the ΔarcA mutant strain exhibited higher motility than the WT strain due to ArcA directly repressed flrA expression. We further discovered that CytR directly enhanced fliK expression, which explained why the ΔcytR mutant strain was retarded in motility. On the other hand, cytR was a direct ArcA target and cytR expression was directly repressed by ArcA. As expected, cytR expression was down-regulated.
Conclusions
Overall, ArcA plays a critical role in V. cholerae motility by regulating flrA expression directly and fliK indirectly in the manner of cytR.
Collapse
|
15
|
The effect of ArcA on the growth, motility, biofilm formation, and virulence of Plesiomonas shigelloides. BMC Microbiol 2021; 21:266. [PMID: 34607564 PMCID: PMC8489083 DOI: 10.1186/s12866-021-02322-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 09/06/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The anoxic redox control binary system plays an important role in the response to oxygen as a signal in the environment. In particular, phosphorylated ArcA, as a global transcription factor, binds to the promoter regions of its target genes to regulate the expression of aerobic and anaerobic metabolism genes. However, the function of ArcA in Plesiomonas shigelloides is unknown. RESULTS In the present study, P. shigelloides was used as the research object. The differences in growth, motility, biofilm formation, and virulence between the WT strain and the ΔarcA isogenic deletion mutant strain were compared. The data showed that the absence of arcA not only caused growth retardation of P. shigelloides in the log phase, but also greatly reduced the glucose utilization in M9 medium before the stationary phase. The motility of the ΔarcA mutant strain was either greatly reduced when grown in swim agar, or basically lost when grown in swarm agar. The electrophoretic mobility shift assay results showed that ArcA bound to the promoter regions of the flaK, rpoN, and cheV genes, indicating that ArcA directly regulates the expression of these three motility-related genes in P. shigelloides. Meanwhile, the ability of the ΔarcA strain to infect Caco-2 cells was reduced by 40%; on the contrary, its biofilm formation was enhanced. Furthermore, the complementation of the WT arcA gene from pBAD33-arcA+ was constructed and all of the above features of the pBAD33-arcA+ complemented strain were restored to the WT level. CONCLUSIONS We showed the effect of ArcA on the growth, motility, biofilm formation, and virulence of Plesiomonas shigelloides, and demonstrated that ArcA functions as a positive regulator controls the motility of P. shigelloides by directly regulating the expression of flaK, rpoN and cheV genes.
Collapse
|
16
|
Xie P, Wang J, Liang H, Gao H. Shewanella oneidensis arcA Mutation Impairs Aerobic Growth Mainly by Compromising Translation. Life (Basel) 2021; 11:life11090926. [PMID: 34575075 PMCID: PMC8470723 DOI: 10.3390/life11090926] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 08/30/2021] [Accepted: 08/30/2021] [Indexed: 12/27/2022] Open
Abstract
Arc (anoxic redox control), one of the most intensely investigated two-component regulatory systems in γ-proteobacteria, plays a major role in mediating the metabolic transition from aerobiosis to anaerobiosis. In Shewanella oneidensis, a research model for respiratory versatility, Arc is crucial for aerobic growth. However, how this occurs remains largely unknown. In this study, we demonstrated that the loss of the response regulator ArcA distorts the correlation between transcription and translation by inhibiting the ribosome biosynthesis. This effect largely underlies the growth defect because it concurs with the effect of chloramphenicol, which impairs translation. Reduced transcription of ArcA-dependent ribosomal protein S1 appears to have a significant impact on ribosome assembly. We further show that the lowered translation efficiency is not accountable for the envelope defect, another major defect resulting from the ArcA loss. Overall, our results suggest that although the arcA mutation impairs growth through multi-fold complex impacts in physiology, the reduced translation efficacy appears to be a major cause for the phenotype, demonstrating that Arc is a primary system that coordinates proteomic resources with metabolism in S. oneidensis.
Collapse
|
17
|
The Amino Acid-mTORC1 Pathway Mediates APEC TW-XM-Induced Inflammation in bEnd.3 Cells. Int J Mol Sci 2021; 22:ijms22179245. [PMID: 34502151 PMCID: PMC8431488 DOI: 10.3390/ijms22179245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/19/2021] [Accepted: 08/24/2021] [Indexed: 11/16/2022] Open
Abstract
The blood-brain barrier (BBB) is key to establishing and maintaining homeostasis in the central nervous system (CNS); meningitis bacterial infection can disrupt the integrity of BBB by inducing an inflammatory response. The changes in the cerebral uptake of amino acids may contribute to inflammatory response during infection and were accompanied by high expression of amino acid transporters leading to increased amino acid uptake. However, it is unclear whether amino acid uptake is changed and how to affect inflammatory responses in mouse brain microvascular endothelial (bEnd.3) cells in response to Avian Pathogenic Escherichia coli TW-XM (APEC XM) infection. Here, we firstly found that APEC XM infection could induce serine (Ser) and glutamate (Glu) transport from extracellular into intracellular in bEnd.3 cells. Meanwhile, we also shown that the expression sodium-dependent neutral amino acid transporter 2 (SNAT2) for Ser and excitatory amino acid transporter 4 (EAAT4) for Glu was also significantly elevated during infection. Then, in amino acid deficiency or supplementation medium, we found that Ser or Glu transport were involving in increasing SNAT2 or EAAT4 expression, mTORC1 (mechanistic target of rapamycin complex 1) activation and inflammation, respectively. Of note, Ser or Glu transport were inhibited after SNAT2 silencing or EAAT4 silencing, resulting in inhibition of mTORC1 pathway activation, and inflammation compared with the APEC XM infection group. Moreover, pEGFP-SNAT2 overexpression and pEGFP-EAAT4 overexpression in bEnd.3 cells all could promote amino acid uptake, activation of the mTORC1 pathway and inflammation during infection. We further found mTORC1 silencing could inhibit inflammation, the expression of SNAT2 and EAAT4, and amino acid uptake. Taken together, our results demonstrated that APEC TW-XM infection can induce Ser or Glu uptake depending on amino acid transporters transportation, and then activate amino acid-mTORC1 pathway to induce inflammation in bEnd.3 cells.
Collapse
|
18
|
Avian Pathogenic Escherichia coli (APEC): An Overview of Virulence and Pathogenesis Factors, Zoonotic Potential, and Control Strategies. Pathogens 2021; 10:pathogens10040467. [PMID: 33921518 PMCID: PMC8069529 DOI: 10.3390/pathogens10040467] [Citation(s) in RCA: 122] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/05/2021] [Accepted: 04/09/2021] [Indexed: 02/07/2023] Open
Abstract
Avian pathogenic Escherichia coli (APEC) causes colibacillosis in avian species, and recent reports have suggested APEC as a potential foodborne zoonotic pathogen. Herein, we discuss the virulence and pathogenesis factors of APEC, review the zoonotic potential, provide the current status of antibiotic resistance and progress in vaccine development, and summarize the alternative control measures being investigated. In addition to the known virulence factors, several other factors including quorum sensing system, secretion systems, two-component systems, transcriptional regulators, and genes associated with metabolism also contribute to APEC pathogenesis. The clear understanding of these factors will help in developing new effective treatments. The APEC isolates (particularly belonging to ST95 and ST131 or O1, O2, and O18) have genetic similarities and commonalities in virulence genes with human uropathogenic E. coli (UPEC) and neonatal meningitis E. coli (NMEC) and abilities to cause urinary tract infections and meningitis in humans. Therefore, the zoonotic potential of APEC cannot be undervalued. APEC resistance to almost all classes of antibiotics, including carbapenems, has been already reported. There is a need for an effective APEC vaccine that can provide protection against diverse APEC serotypes. Alternative therapies, especially the virulence inhibitors, can provide a novel solution with less likelihood of developing resistance.
Collapse
|
19
|
Harrison LM, Lacher DW, Mammel MK, Leonard SR. Comparative Transcriptomics of Shiga Toxin-Producing and Commensal Escherichia coli and Cytokine Responses in Colonic Epithelial Cell Culture Infections. Front Cell Infect Microbiol 2020; 10:575630. [PMID: 33194815 PMCID: PMC7649339 DOI: 10.3389/fcimb.2020.575630] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 10/07/2020] [Indexed: 12/12/2022] Open
Abstract
Ingestion of Shiga toxin-producing Escherichia coli (STEC) can result in a range of illness severity from asymptomatic to hemorrhagic colitis and death; thus risk assessment of STEC strains for human pathogenicity is important in the area of food safety. Illness severity depends in part on the combination of virulence genes carried in the genome, which can vary between strains even of identical serotype. To better understand how core genes are regulated differently among strains and to identify possible novel STEC virulence gene candidates that could be added to the risk assessment repertoire, we used comparative transcriptomics to investigate global gene expression differences between two STEC strains associated with severe illness and a commensal E. coli strain during in vitro intestinal epithelial cell (IEC) infections. Additionally, we compared a wide array of concomitant cytokine levels produced by the IECs. The cytokine expression levels were examined for a pattern representing STEC pathogenicity; however, while one STEC strain appeared to elicit a proinflammatory response, infection by the other strain produced a pattern comparable to the commensal E. coli. This result may be explained by the significant differences in gene content and expression observed between the STEC strains. RNA-Seq analysis revealed considerable disparity in expression of genes in the arginine and tryptophan biosynthesis/import pathways between the STEC strains and the commensal E. coli strain, highlighting the important role some amino acids play in STEC colonization and survival. Contrasting differential expression patterns were observed for genes involved in respiration among the three strains suggesting that metabolic diversity is a strategy utilized to compete with resident microflora for successful colonization. Similar temporal expression results for known and putative virulence genes were observed in the STEC strains, revealing strategies used for survival prior to and after initial adherence to IECs. Additionally, three genes encoding hypothetical proteins located in mobile genetic elements were, after interrogation of a large set of E. coli genomes, determined to likely represent novel STEC virulence factors.
Collapse
Affiliation(s)
- Lisa M Harrison
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, Laurel, MD, United States
| | - David W Lacher
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, Laurel, MD, United States
| | - Mark K Mammel
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, Laurel, MD, United States
| | - Susan R Leonard
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, Laurel, MD, United States
| |
Collapse
|
20
|
Khan F, Tabassum N, Pham DTN, Oloketuyi SF, Kim YM. Molecules involved in motility regulation in Escherichia coli cells: a review. BIOFOULING 2020; 36:889-908. [PMID: 33028083 DOI: 10.1080/08927014.2020.1826939] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 06/11/2023]
Abstract
The initial colonization of the host organism by commensal, probiotic, and pathogenic Escherichia coli strains is an important step in the development of infections and biofilms. Sensing and colonization of host cell surfaces are governed by flagellar and fimbriae/pili appendages, respectively. Biofilm formation confers great advantages on pathogenic E. coli cells such as protection against the host immune system, antimicrobial agents, and several environmental stress factors. The transition from planktonic to sessile physiological states involves several signaling cascades and factors responsible for the regulation of flagellar motility in E. coli cells. These regulatory factors have thus become important targets to control pathogenicity. Hence, attenuation of flagellar motility is considered a potential therapy against pathogenic E. coli. The present review describes signaling pathways and proteins involved in direct or indirect regulation of flagellar motility. Furthermore, application strategies for antimotility natural or synthetic compounds are discussed also.
Collapse
Affiliation(s)
- Fazlurrahman Khan
- Institute of Food Science, Pukyong National University, Busan, Republic of Korea
| | - Nazia Tabassum
- Industrial Convergence Bionix Engineering, Pukyong National University, Busan, Republic of Korea
| | - Dung Thuy Nguyen Pham
- Department of Food Science and Technology, Pukyong National University, Busan, Republic of Korea
| | | | - Young-Mog Kim
- Institute of Food Science, Pukyong National University, Busan, Republic of Korea
- Department of Food Science and Technology, Pukyong National University, Busan, Republic of Korea
| |
Collapse
|
21
|
Dineshkumar K, Aparna V, Wu L, Wan J, Abdelaziz MH, Su Z, Wang S, Xu H. Bacterial bug-out bags: outer membrane vesicles and their proteins and functions. J Microbiol 2020; 58:531-542. [DOI: 10.1007/s12275-020-0026-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 05/06/2020] [Accepted: 05/12/2020] [Indexed: 01/08/2023]
|
22
|
Shu X, Singh M, Karampudi NBR, Bridges DF, Kitazumi A, Wu VCH, De los Reyes BG. Xenobiotic Effects of Chlorine Dioxide to Escherichia coli O157:H7 on Non-host Tomato Environment Revealed by Transcriptional Network Modeling: Implications to Adaptation and Selection. Front Microbiol 2020; 11:1122. [PMID: 32582084 PMCID: PMC7286201 DOI: 10.3389/fmicb.2020.01122] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 05/05/2020] [Indexed: 12/16/2022] Open
Abstract
Escherichia coli serotype O157:H7 is one of the major agents of pathogen outbreaks associated with fresh fruits and vegetables. Gaseous chlorine dioxide (ClO2) has been reported to be an effective intervention to eliminate bacterial contamination on fresh produce. Although remarkable positive effects of low doses of ClO2 have been reported, the genetic regulatory machinery coordinating the mechanisms of xenobiotic effects and the potential bacterial adaptation remained unclear. This study examined the temporal transcriptome profiles of E. coli O157:H7 during exposure to different doses of ClO2 in order to elucidate the genetic mechanisms underlying bacterial survival under such harsh conditions. Dosages of 1 μg, 5 μg, and 10 μg ClO2 per gram of tomato fruits cause different effects with dose-by-time dynamics. The first hour of exposure to 1 μg and 5 μg ClO2 caused only partial killing with significant growth reduction starting at the second hour, and without further significant reduction at the third hour. However, 10 μg ClO2 exposure led to massive bacterial cell death at 1 h with further increase in cell death at 2 and 3 h. The first hour exposure to 1 μg ClO2 caused activation of primary defense and survival mechanisms. However, the defense response was attenuated during the second and third hours. Upon treatment with 5 μg ClO2, the transcriptional networks showed massive downregulation of pathogenesis and stress response genes at the first hour of exposure, with decreasing number of differentially expressed genes at the second and third hours. In contrast, more genes were further downregulated with exposure to 10 μg ClO2 at the first hour, with the number of both upregulated and downregulated genes significantly decreasing at the second hour. A total of 810 genes were uniquely upregulated at the third hour at 10 μg ClO2, suggesting that the potency of xenobiotic effects had led to potential adaptation. This study provides important knowledge on the possible selection of target molecules for eliminating bacterial contamination on fresh produce without overlooking potential risks of adaptation.
Collapse
Affiliation(s)
- Xiaomei Shu
- Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, United States
| | - Manavi Singh
- Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, United States
| | | | - David F. Bridges
- Produce Safety and Microbiology Research, Western Regional Research Center, United States Department of Agriculture – Agricultural Research Service, Albany, CA, United States
| | - Ai Kitazumi
- Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, United States
| | - Vivian C. H. Wu
- Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, United States
- Produce Safety and Microbiology Research, Western Regional Research Center, United States Department of Agriculture – Agricultural Research Service, Albany, CA, United States
| | | |
Collapse
|
23
|
Gao Q, Su S, Li X, Wang H, Liu J, Gao S. Transcriptional analysis of RstA/RstB in avian pathogenic Escherichia coli identifies its role in the regulation of hdeD-mediated virulence and survival in chicken macrophages. Vet Microbiol 2019; 241:108555. [PMID: 31928702 DOI: 10.1016/j.vetmic.2019.108555] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/16/2019] [Accepted: 12/17/2019] [Indexed: 10/25/2022]
Abstract
Avian pathogenic Escherichia coli (APEC) causes avian colibacillosis in poultry, which is characterized by systemic infections such as septicemia, air sacculitis, and pericarditis. APEC uses two-component regulatory systems (TCSs) to handle the stressful environments present in infected hosts. While many TCSs in E. coli have been well characterized, the RstA/RstB system in APEC has not been thoroughly investigated. The involvement of the RstA regulator in APEC pathogenesis was demonstrated during previous studies investigating its role in APEC persistence in chicken macrophages and respiratory infections. However, the mechanism underlying this phenomenon has not been clarified. Transcriptional analysis of the effect of rstAB deletion was therefore performed to improve the understanding of the RstA/RstB regulatory mechanism, and particularly its role in virulence. The transcriptomes of the rstAB mutant and the wild-type strain E058 were compared during their growth in the bloodstreams of challenged chickens. Overall, 198 differentially expressed (DE) genes were identified, and these indicated that RstA/RstB mainly regulates systems involved in nitrogen metabolism, iron acquisition, and acid resistance. Phenotypic assays indicated that the rstAB mutant responded more to an acidic pH than the wild-type strain did, possibly because of the repression of the acid-resistance operons hdeABD and gadABE by the deletion of rstAB. Based on the reported RstA box motif TACATNTNGTTACA, we identified four possible RstA target genes (hdeD, fadE, narG, and metE) among the DE genes. An electrophoretic mobility shift assay confirmed that RstA binds directly to the promoter of hdeD, and β-galactosidase assays showed that hdeD expression was reduced by rstAB deletion, indicating that RstA directly regulates hdeD expression. The hdeD mutation resulted in virulence attenuation in both cultured chicken macrophages and experimentally infected chickens. In conclusion, our data suggest that RstA affects APEC E058 virulence partly by directly regulating the acidic resistance gene hdeD.
Collapse
Affiliation(s)
- Qingqing Gao
- Animal Infectious Disease Laboratory, Ministry of Agriculture, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, 225009, PR China
| | - Senyan Su
- Animal Infectious Disease Laboratory, Ministry of Agriculture, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, 225009, PR China
| | - Xi Li
- Animal Infectious Disease Laboratory, Ministry of Agriculture, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, 225009, PR China
| | - Hang Wang
- Animal Infectious Disease Laboratory, Ministry of Agriculture, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, 225009, PR China
| | - Jinbiao Liu
- Animal Infectious Disease Laboratory, Ministry of Agriculture, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, 225009, PR China
| | - Song Gao
- Animal Infectious Disease Laboratory, Ministry of Agriculture, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, 225009, PR China.
| |
Collapse
|
24
|
Identification of Host Adaptation Genes in Extraintestinal Pathogenic Escherichia coli during Infection in Different Hosts. Infect Immun 2019; 87:IAI.00666-19. [PMID: 31501251 DOI: 10.1128/iai.00666-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 08/30/2019] [Indexed: 01/11/2023] Open
Abstract
Extraintestinal pathogenic Escherichia coli (ExPEC) is an important human and animal pathogen. Despite the apparent similarities in their known virulence attributes, some ExPEC strains can cross the host species barrier and present a zoonotic potential, whereas other strains exhibit host specificity, suggesting the existence of unknown mechanisms that remain to be identified. We applied a transposon-directed insertion site sequencing (TraDIS) strategy to investigate the ExPEC XM strain, which is capable of crossing the host species barrier, and to screen for virulence-essential genes in both mammalian (mouse) and avian (duck) models of E. coli-related septicemia. We identified 151 genes essential for systemic infection in both mammalian and avian models, 97 required only in the mammalian model, and 280 required only in the avian model. Ten genes/gene clusters were selected for further validation, and their contributions to ExPEC virulence in both mammalian and avian models or mammalian- or avian-only models were confirmed by animal tests. This represents the first comprehensive genome-wide analysis of virulence-essential genes required for systemic infections in two different host species and provides a further comprehensive understanding of ExPEC-related virulence, host specificity, and adaptation.
Collapse
|
25
|
CitAB Two-Component System-Regulated Citrate Utilization Contributes to Vibrio cholerae Competitiveness with the Gut Microbiota. Infect Immun 2019; 87:IAI.00746-18. [PMID: 30559220 DOI: 10.1128/iai.00746-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 12/09/2018] [Indexed: 01/05/2023] Open
Abstract
Citrate is a ubiquitous compound and can be utilized by many bacterial species, including enteric pathogens, as a carbon and energy source. Genes involved in citrate utilization have been extensively studied in some enteric bacteria, such as Klebsiella pneumoniae; however, their role in pathogenesis is still not clear. In this study, we investigated citrate utilization and regulation in Vibrio cholerae, the causative agent of cholera. The putative anaerobic citrate fermentation genes in V. cholerae, consisting of citCDEFXG, citS-oadGAB, and the two-component system (TCS) genes citAB, are highly homologous to those in K. pneumoniae Deletion analysis shows that these cit genes are essential for V. cholerae growth when citrate is the sole carbon source. The expression of citC and citS operons was dependent on citrate and CitAB, whose transcription was autorepressed and regulated by another TCS regulator, ArcA. In addition, citrate fermentation was under the control of catabolite repression. Mouse colonization experiments showed that V. cholerae can utilize citrate in vivo using the citrate fermentation pathway and that V. cholerae likely needs to compete with other members of the gut microbiota to access citrate in the gut.
Collapse
|
26
|
Ma J, An C, Jiang F, Yao H, Logue C, Nolan LK, Li G. Extraintestinal pathogenic Escherichia coli increase extracytoplasmic polysaccharide biosynthesis for serum resistance in response to bloodstream signals. Mol Microbiol 2018; 110:689-706. [PMID: 29802751 DOI: 10.1111/mmi.13987] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 05/14/2018] [Accepted: 05/14/2018] [Indexed: 01/08/2023]
Abstract
Extraintestinal pathogenic Escherichia coli (ExPEC) is one of the leading causes of bloodstream infections. Characteristically, these organisms exhibit strong resistance to the bactericidal action of host serum. Although numerous serum resistance factors in ExPEC have been identified, their regulatory mechanisms during in vivo infection remain largely unknown. Here, RNA sequencing analyses together with quantitative reverse-transcription PCR revealed that ExPEC genes involved in the biosynthesis of extracytoplasmic polysaccharides (ECPs) including K-capsule, lipopolysaccharide (LPS), colanic acid, peptidoglycan and Yjb exopolysaccharides were significantly upregulated in response to serum under low oxygen conditions and during bloodstream infection. The oxygen sensor FNR directly activated the expression of K-capsule and colanic acid and also indirectly modulated the expression of colanic acid, Yjb exopolysaccharides and peptidoglycan via the known Rcs regulatory system. The global regulator Fur directly or indirectly repressed the expression ofECP biosynthesis genes in iron replete media, whereas the low iron conditions in the bloodstream could relieve Fur repression. Using in vitro and animal models, FNR, Fur and the Rcs system were confirmed as contributing to ExPEC ECP production, serum resistance and virulence. Altogether, these findings indicated that the global regulators FNR andFur and the signaling transduction system Rcs coordinately regulated the expression of ECP biosynthesis genes leading to increased ExPEC serum resistance in response to low oxygen and low iron levels in the bloodstream.
Collapse
Affiliation(s)
- Jiale Ma
- Department of Veterinary Preventive Medicine College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.,Department of Veterinary Diagnostic and Production Animal Medicine College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Chunxia An
- Department of Veterinary Preventive Medicine College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Fengwei Jiang
- Department of Veterinary Preventive Medicine College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.,Department of Veterinary Diagnostic and Production Animal Medicine College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Huochun Yao
- Department of Veterinary Preventive Medicine College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Catherine Logue
- Department of Veterinary Microbiology and Preventive Medicine College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Lisa K Nolan
- Department of Veterinary Microbiology and Preventive Medicine College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Ganwu Li
- Department of Veterinary Diagnostic and Production Animal Medicine College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA.,State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute Chinese Academy of Agricultural Sciences, 678 Haping Street, Harbin, 150069, China
| |
Collapse
|
27
|
Wang Z, Sun J, Xia T, Liu Y, Fu J, Lo YK, Chang C, Yan A, Liu X. Proteomic Delineation of the ArcA Regulon in Salmonella Typhimurium During Anaerobiosis. Mol Cell Proteomics 2018; 17:1937-1947. [PMID: 30038032 DOI: 10.1074/mcp.ra117.000563] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 06/08/2018] [Indexed: 12/14/2022] Open
Abstract
Salmonella enterica serovar Typhimurium (S. Typhimurium) is one of the most used models for bacterial pathogenesis and successful infection requires its adaptation to the low oxygen environment in host gastrointestinal tracts. Central to this process is the Arc (aerobic respiratory control) two-component regulatory system that contains a sensor kinase ArcB and a response regulator ArcA. Nevertheless, a comprehensive profile of the ArcA regulon on the proteome level is still lacking in S. Typhimurium. Here we quantitatively profiled Salmonella proteome during anaerobiosis in an arcA-deleting mutant compared with its parental strain. In addition to known processes under its control, notably we found that ArcA represses ethanolamine utilization by directly binding to the promoter region of the eut operon. Furthermore, we found opposing changes of several bacterial genes on the protein and transcript levels in the arcA-deleting mutant including the virulence genes of Salmonella pathogenicity island 1 (SPI-1), thereby indicating potentially prevalent post-transcriptional regulatory mechanisms. Altogether, our study provides important new insights into ArcA-dependent bacterial physiology and virulence during Salmonella anaerobiosis.
Collapse
Affiliation(s)
- Zhen Wang
- From the ‡Institute of Analytical Chemistry and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Jingjing Sun
- §School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Tingying Xia
- §School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Yanhua Liu
- From the ‡Institute of Analytical Chemistry and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Jiaqi Fu
- From the ‡Institute of Analytical Chemistry and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Yat Kei Lo
- §School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Cheng Chang
- ¶State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Lifeomics, National Center for Protein Sciences (Beijing), Beijing 102206, P.R. China
| | - Aixin Yan
- §School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China;
| | - Xiaoyun Liu
- From the ‡Institute of Analytical Chemistry and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China;
| |
Collapse
|
28
|
Bao K, Bostanci N, Thurnheer T, Grossmann J, Wolski WE, Thay B, Belibasakis GN, Oscarsson J. Aggregatibacter actinomycetemcomitans H-NS promotes biofilm formation and alters protein dynamics of other species within a polymicrobial oral biofilm. NPJ Biofilms Microbiomes 2018; 4:12. [PMID: 29844920 PMCID: PMC5964231 DOI: 10.1038/s41522-018-0055-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 04/03/2018] [Accepted: 04/19/2018] [Indexed: 12/12/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans is a Gram-negative organism, strongly associated with aggressive forms of periodontitis. An important virulence property of A. actinomycetemcomitans is its ability to form tenacious biofilms that can attach to abiotic as well as biotic surfaces. The histone-like (H-NS) family of nucleoid-structuring proteins act as transcriptional silencers in many Gram-negative bacteria. To evaluate the role of H-NS in A. actinomycetemcomitans, hns mutant derivatives of serotype a strain D7S were generated. Characteristics of the hns mutant phenotype included shorter and fewer pili, and substantially lower monospecies biofilm formation relative to the wild type. Furthermore, the D7S hns mutant exhibited significantly reduced growth within a seven-species oral biofilm model. However, no apparent difference was observed regarding the numbers and proportions of the remaining six species regardless of being co-cultivated with D7S hns or its parental strain. Proteomics analysis of the strains grown in monocultures confirmed the role of H-NS as a repressor of gene expression in A. actinomycetemcomitans. Interestingly, proteomics analysis of the multispecies biofilms indicated that the A. actinomycetemcomitans wild type and hns mutant imposed different regulatory effects on the pattern of protein expression in the other species, i.e., mainly Streptococcus spp., Fusobacterium nucleatum, and Veillonella dispar. Gene ontology analysis revealed that a large portion of the differentially regulated proteins was related to translational activity. Taken together, our data suggest that, apart from being a negative regulator of protein expression in A. actinomycetemcomitans, H-NS promotes biofilm formation and may be an important factor for survival of this species within a multispecies biofilm. A member of a specific group of gene-regulating proteins promotes biofilm formation by a bacterium associated with aggressive forms of gum disease. Forming biofilms helps the bacterium to cause persistent infections. Researchers at Karolinska Institutet and Umeå University (Sweden), and University of Zürich (Switzerland), led by Jan Oscarsson at Umeå University, investigated the role of the “histone-like” protein H-NS in Aggregatibacter actinomycetemcomitans infections. These proteins are known to suppress the activity of specific genes in many bacteria, a property confirmed in this research. By studying mutant bacterial strains deficient in H-NS protein, the researchers demonstrated that this protein promotes the formation of biofilms by the bacteria. The results suggest that H-NS plays a significant role in allowing Aggregatibacter actinomycetemcomitans to thrive in biofilms containing mixed populations of bacteria. This effect appears to involve activating production of hair-like appendages called pili on the bacterial surface.
Collapse
Affiliation(s)
- Kai Bao
- 1Division of Oral Diseases, Department of Dental Medicine, Karolinska Institutet, Huddinge, Solnavägen, Sweden.,2Division of Oral Microbiology and Immunology, Center of Dental Medicine, University of Zürich, Zürich, Switzerland
| | - Nagihan Bostanci
- 1Division of Oral Diseases, Department of Dental Medicine, Karolinska Institutet, Huddinge, Solnavägen, Sweden
| | - Thomas Thurnheer
- 2Division of Oral Microbiology and Immunology, Center of Dental Medicine, University of Zürich, Zürich, Switzerland
| | - Jonas Grossmann
- 3Functional Genomics Center, ETH Zürich and University of Zürich, Zürich, Switzerland
| | - Witold E Wolski
- 3Functional Genomics Center, ETH Zürich and University of Zürich, Zürich, Switzerland
| | - Bernard Thay
- 4Oral Microbiology, Department of Odontology, Umeå University, Umeå, Sweden
| | - Georgios N Belibasakis
- 1Division of Oral Diseases, Department of Dental Medicine, Karolinska Institutet, Huddinge, Solnavägen, Sweden
| | - Jan Oscarsson
- 4Oral Microbiology, Department of Odontology, Umeå University, Umeå, Sweden
| |
Collapse
|
29
|
Gao W, Yin J, Bao L, Wang Q, Hou S, Yue Y, Yao W, Gao X. Engineering Extracellular Expression Systems in Escherichia coli Based on Transcriptome Analysis and Cell Growth State. ACS Synth Biol 2018; 7:1291-1302. [PMID: 29668266 DOI: 10.1021/acssynbio.7b00400] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Escherichia coli extracellular expression systems have a number of advantages over other systems, such as lower pyrogen levels and a simple purification process. Various approaches, such as the generation of leaky mutants via chromosomal engineering, have been explored for this expression system. However, extracellular protein yields in leaky mutants are relatively low compared to that in intracellular expression systems and therefore need to be improved. In this work, we describe the construction, characterization, and mechanism of enhanced extracellular expression in Escherichia coli. On the basis of the localizations, functions, and transcription levels of cell envelope proteins, we systematically elucidated the effects of multiple gene deletions on cell growth and extracellular expression using modified CRISPR/Cas9-based genome editing and a FlAsH labeling assay. High extracellular yields of heterologous proteins of different sizes were obtained by screening multiple gene mutations. The enhancement of extracellular secretion was associated with the derepression of translation and translocation. This work utilized universal methods in the design of extracellular expression systems for genes not directly associated with protein synthesis that were used to generate strains with higher protein expression capability. We anticipate that extracellular expression systems may help to shed light on the poorly understood aspects of these secretion processes as well as to further assist in the construction of engineered prokaryotic cells for efficient extracellular production of heterologous proteins.
Collapse
Affiliation(s)
- Wen Gao
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals and State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Jun Yin
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals and State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Lichen Bao
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals and State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Qun Wang
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals and State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Shan Hou
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals and State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Yali Yue
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals and State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Wenbing Yao
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals and State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Xiangdong Gao
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals and State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
| |
Collapse
|
30
|
Breland EJ, Eberly AR, Hadjifrangiskou M. An Overview of Two-Component Signal Transduction Systems Implicated in Extra-Intestinal Pathogenic E. coli Infections. Front Cell Infect Microbiol 2017; 7:162. [PMID: 28536675 PMCID: PMC5422438 DOI: 10.3389/fcimb.2017.00162] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 04/18/2017] [Indexed: 11/13/2022] Open
Abstract
Extra-intestinal pathogenic E. coli (ExPEC) infections are common in mammals and birds. The predominant ExPEC types are avian pathogenic E. coli (APEC), neonatal meningitis causing E. coli/meningitis associated E. coli (NMEC/MAEC), and uropathogenic E. coli (UPEC). Many reviews have described current knowledge on ExPEC infection strategies and virulence factors, especially for UPEC. However, surprisingly little has been reported on the regulatory modules that have been identified as critical in ExPEC pathogenesis. Two-component systems (TCSs) comprise the predominant method by which bacteria respond to changing environments and play significant roles in modulating bacterial fitness in diverse niches. Recent studies have highlighted the potential of manipulating signal transduction systems as a means to chemically re-wire bacterial pathogens, thereby reducing selective pressure and avoiding the emergence of antibiotic resistance. This review begins by providing a brief introduction to characterized infection strategies and common virulence factors among APEC, NMEC, and UPEC and continues with a comprehensive overview of two-component signal transduction networks that have been shown to influence ExPEC pathogenesis.
Collapse
Affiliation(s)
- Erin J Breland
- Department of Pharmacology, Vanderbilt University Medical CenterNashville, TN, USA
| | - Allison R Eberly
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical CenterNashville, TN, USA
| | - Maria Hadjifrangiskou
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical CenterNashville, TN, USA.,Department of Urology, Vanderbilt University Medical CenterNashville, TN, USA
| |
Collapse
|
31
|
Cai W, Cai X, Yang Y, Yan S, Zhang H. Transcriptional Control of Dual Transporters Involved in α-Ketoglutarate Utilization Reveals Their Distinct Roles in Uropathogenic Escherichia coli. Front Microbiol 2017; 8:275. [PMID: 28270808 PMCID: PMC5318444 DOI: 10.3389/fmicb.2017.00275] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 02/09/2017] [Indexed: 12/14/2022] Open
Abstract
Uropathogenic Escherichia coli (UPEC) are the primary causative agents of urinary tract infections. Some UPEC isolates are able to infect renal proximal tubule cells, and can potentially cause pyelonephritis. We have previously shown that to fulfill their physiological roles renal proximal tubule cells accumulate high concentrations of α-ketoglutarate (KG) and that gene cluster c5032–c5039 contribute to anaerobic utilization of KG by UPEC str. CFT073, thereby promoting its in vivo fitness. Given the importance of utilizing KG for UPEC, this study is designed to investigate the roles of two transporters KgtP and C5038 in KG utilization, their transcriptional regulation, and their contributions to UPEC fitness in vivo. Our phylogenetic analyses support that kgtP is a widely conserved locus in commensal and pathogenic E. coli, while UPEC-associated c5038 was acquired through horizontal gene transfer. Global anaerobic transcriptional regulators Fumarate and nitrate reduction (FNR) and ArcA induced c5038 expression in anaerobiosis, and C5038 played a major role in anaerobic growth on KG. KgtP was required for aerobic growth on KG, and its expression was repressed by FNR and ArcA under anaerobic conditions. Analyses of FNR and ArcA binding sites and results of EMS assays suggest that FNR and ArcA likely inhibit kgtP expression through binding to the –35 region of kgtP promoter and occluding the occupancy of RNA polymerases. Gene c5038 can be specifically induced by KG, whereas the expression of kgtP does not respond to KG, yet can be stimulated during growth on glycerol. In addition, c5038 and kgtP expression were further shown to be controlled by different alternative sigma factors RpoN and RpoS, respectively. Furthermore, dual-strain competition assays in a murine model showed that c5038 mutant but not kgtP mutant was outcompeted by the wild-type strain during the colonization of murine bladders and kidneys, highlighting the importance of C5038 under in vivo conditions. Therefore, different transcriptional regulation led to distinct roles played by C5038 and KgtP in KG utilization and fitness in vivo. This study thus potentially expanded our understanding of UPEC pathobiology.
Collapse
Affiliation(s)
- Wentong Cai
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Nanjing Agricultural University Nanjing, China
| | - Xuwang Cai
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University Wuhan, China
| | - Yongwu Yang
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Nanjing Agricultural University Nanjing, China
| | - Shigan Yan
- School of Bioengineering, Shandong Provincial Key Laboratory of Microbial Engineering, Qilu University of Technology Jinan, China
| | - Haibin Zhang
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Nanjing Agricultural UniversityNanjing, China; Department of Clinical Veterinary Science, College of Veterinary Medicine, Nanjing Agricultural UniversityNanjing, China
| |
Collapse
|
32
|
Varas M, Valdivieso C, Mauriaca C, Ortíz-Severín J, Paradela A, Poblete-Castro I, Cabrera R, Chávez FP. Multi-level evaluation of Escherichia coli polyphosphate related mutants using global transcriptomic, proteomic and phenomic analyses. Biochim Biophys Acta Gen Subj 2017; 1861:871-883. [PMID: 28069396 DOI: 10.1016/j.bbagen.2017.01.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 12/26/2016] [Accepted: 01/05/2017] [Indexed: 12/20/2022]
Abstract
BACKGROUND Polyphosphate (polyP) is a linear biopolymer found in all living cells. In bacteria, mutants lacking polyphosphate kinase 1 (PPK1), the enzyme responsible for synthesis of most polyP, have many structural and functional defects. However, little is known about the causes of these pleiotropic alterations. The link between ppk1 deletion and those numerous phenotypes observed can be the result of complex molecular interactions that can be elucidated via a systems biology approach. METHODS By integrating different omics levels (transcriptome, proteome and phenome), we described the functioning of various metabolic pathways among Escherichia coli polyphosphate mutant strains (Δppk1, Δppx, and ΔpolyP). Bioinformatic analyses reveal the complex metabolic and regulatory bases of the phenotypes unique to polyP mutants. RESULTS Our results suggest that during polyP deficiency (Δppk1 mutant), metabolic pathways needed for energy supply are up-regulated, including fermentation, aerobic and anaerobic respiration. Transcriptomic and q-proteomic contrasting changes between Δppk1 and Δppx mutant strains were observed in those central metabolic pathways and confirmed by using Phenotypic microarrays. In addition, our results suggest a regulatory connection between polyP, second messenger metabolism, alternative Sigma/Anti-Sigma factors and type-II toxin-antitoxin (TA) systems. CONCLUSIONS We suggest a broader role for polyP via regulation of ATP-dependent proteolysis of type II toxin-antitoxin system and alternative Sigma/Anti-Sigma factors, that could explain the multiple structural and functional deficiencies described due to alteration of polyP metabolism. GENERAL SIGNIFICANCE Understanding the interplay of polyP in bacterial metabolism using a systems biology approach can help to improve design of novel antimicrobials toward pathogens.
Collapse
Affiliation(s)
- Macarena Varas
- Systems Microbiology Laboratory, Department of Biology, Faculty of Science, University of Chile, Chile.
| | - Camilo Valdivieso
- Systems Microbiology Laboratory, Department of Biology, Faculty of Science, University of Chile, Chile; Department of Ecology, Faculty of Science, University of Chile, Chile.
| | - Cecilia Mauriaca
- Systems Microbiology Laboratory, Department of Biology, Faculty of Science, University of Chile, Chile.
| | - Javiera Ortíz-Severín
- Systems Microbiology Laboratory, Department of Biology, Faculty of Science, University of Chile, Chile.
| | | | - Ignacio Poblete-Castro
- Facultad de Ciencias Biológicas, Center for Bioinformatics and Integrative Biology, Biosystems Engineering Laboratory, Universidad Andrés Bello, Chile.
| | - Ricardo Cabrera
- Department of Biology, Faculty of Sciences, University of Chile, Chile.
| | - Francisco P Chávez
- Systems Microbiology Laboratory, Department of Biology, Faculty of Science, University of Chile, Chile.
| |
Collapse
|
33
|
Zhuge X, Tang F, Zhu H, Mao X, Wang S, Wu Z, Lu C, Dai J, Fan H. AutA and AutR, Two Novel Global Transcriptional Regulators, Facilitate Avian Pathogenic Escherichia coli Infection. Sci Rep 2016; 6:25085. [PMID: 27113849 PMCID: PMC4844996 DOI: 10.1038/srep25085] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 04/11/2016] [Indexed: 12/18/2022] Open
Abstract
Bacteria can change its lifestyle during inhabiting in host niches where they survive and replicate by rapidly altering gene expression pattern to accommodate the new environment. In this study, two novel regulators in avian pathogenic Escherichia coli (APEC) were identified and designated as AutA and AutR. RT-PCR and β-galactosidase assay results showed that AutA and AutR co-regulated the expression of adhesin UpaB in APEC strain DE205B. Electrophoretic mobility shift assay showed that AutA and AutR could directly bind the upaB promoter DNA. In vitro transcription assay indicated that AutA could activate the upaB transcription, while AutR inhibited the upaB transcription due to directly suppressing the activating effect of AutA on UpaB expression. Transcriptome analysis showed that AutA and AutR coherently affected the expression of hundreds of genes. Our study confirmed that AutA and AutR co-regulated the expression of DE205B K1 capsule and acid resistance systems in E. coli acid fitness island (AFI). Moreover, phenotypic heterogeneity in expression of K1 capsule and acid resistance systems in AFI during host–pathogen interaction was associated with the regulation of AutA and AutR. Collectively speaking, our studies presented that AutA and AutR are involved in APEC adaptive lifestyle change to facilitate its infection.
Collapse
Affiliation(s)
- Xiangkai Zhuge
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | - Fang Tang
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | - Hongfei Zhu
- Beijing Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xiang Mao
- 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
| | - Zongfu Wu
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | - Chengping Lu
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | - Jianjun Dai
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | - Hongjie Fan
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| |
Collapse
|