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He S, Fong K, Shi C, Shi X. Proteomic and mutagenic analyses for cross-protective mechanisms on ethanol adaptation to freezing stress in Salmonella Enteritidis. Food Control 2023. [DOI: 10.1016/j.foodcont.2022.109376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Qiao Z, Huang J, Cao Y, Shi K, Wang G. Genetics and proteomics analyses reveal the roles of PhoB1 and PhoB2 regulators in bacterial responses to arsenite and phosphate. Res Microbiol 2019; 170:263-271. [PMID: 31279088 DOI: 10.1016/j.resmic.2019.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 06/18/2019] [Accepted: 06/21/2019] [Indexed: 11/25/2022]
Abstract
In bacteria, phosphate (Pi) stress response is governed by the two-component regulatory system, sensor kinase PhoR and its cognate response regulatory protein PhoB. The arsenite [As(III)]-oxidizing bacterium Agrobacterium tumefaciens GW4 contains two phoB genes, phoB1 and phoB2. phoB1 is adjacent to As(III)-oxidizing genes, however, the functions of PhoB1 and PhoB2 remain unclear. Here, phoB1 and phoB2 were each deleted in-frame, and proteomics, qRT-PCR and protein-DNA interaction were performed. We found that (1) phoB1 and phoB2 were both upregulated under low Pi conditions and phoB1 was induced by As(III), but phoB2 was not; (2) deletion of phoB1 reduced As(III)-oxidizing efficiency and protein-DNA interaction analysis showed PhoB1 could interact with aioXSR promoter to regulate As(III) oxidation; (3) deletions of phoB1 or phoB2 both reduced exopolysaccharides (EPS) synthesis; and (4) PhoB1 influenced Pi uptake, As(III) oxidation, EPS synthesis, TCA cycle, energy production and stress response with As(III), and PhoB2 was associated with Pi uptake and EPS synthesis in low Pi conditions. These results showed PhoB1 and PhoB2 were both involved in Pi acquisition, PhoB1 was more important with As(III) and PhoB2 played a major role without As(III). Strain GW4 uses these two regulators to survive under low Pi and arsenic-rich environments.
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Affiliation(s)
- Zixu Qiao
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, PR China.
| | - Jing Huang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, PR China.
| | - Yajing Cao
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, PR China.
| | - Kaixiang Shi
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, PR China.
| | - Gejiao Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, PR China.
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Mechanisms of Bacterial Tolerance and Persistence in the Gastrointestinal and Respiratory Environments. Clin Microbiol Rev 2018; 31:31/4/e00023-18. [PMID: 30068737 DOI: 10.1128/cmr.00023-18] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Pathogens that infect the gastrointestinal and respiratory tracts are subjected to intense pressure due to the environmental conditions of the surroundings. This pressure has led to the development of mechanisms of bacterial tolerance or persistence which enable microorganisms to survive in these locations. In this review, we analyze the general stress response (RpoS mediated), reactive oxygen species (ROS) tolerance, energy metabolism, drug efflux pumps, SOS response, quorum sensing (QS) bacterial communication, (p)ppGpp signaling, and toxin-antitoxin (TA) systems of pathogens, such as Escherichia coli, Salmonella spp., Vibrio spp., Helicobacter spp., Campylobacter jejuni, Enterococcus spp., Shigella spp., Yersinia spp., and Clostridium difficile, all of which inhabit the gastrointestinal tract. The following respiratory tract pathogens are also considered: Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Burkholderia cenocepacia, and Mycobacterium tuberculosis Knowledge of the molecular mechanisms regulating the bacterial tolerance and persistence phenotypes is essential in the fight against multiresistant pathogens, as it will enable the identification of new targets for developing innovative anti-infective treatments.
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Barbosa LC, Goulart CL, Avellar MM, Bisch PM, von Kruger WMA. Accumulation of ornithine lipids in Vibrio cholerae under phosphate deprivation is dependent on VC0489 (OlsF) and PhoBR system. MICROBIOLOGY-SGM 2018; 164:395-399. [PMID: 29458678 DOI: 10.1099/mic.0.000607] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Ornithine lipids (OLs) are phosphorus-free lipids found in many bacteria grown under phosphate deprivation, a condition that activates the PhoBR system and leads to phosphate uptake and metabolism. Two OL synthesis pathways have already been described. One depends on OlsB and OlsA acyltransferases to add, respectively, the first and second acyl chains to an ornithine molecule. The other pathway is carried out by OlsF, a bifunctional enzyme responsible for both acylation steps. Although Vibrio cholerae lacks olsBA genes, an olsF homologue (vc0489) was identified in its genome. In this work we demonstrated that V. cholerae produces OLs and expresses vc0489 in response to phosphate depletion, in a PhoBR-dependent manner. In Escherichia coli, under similar condition, vc0489 expression leads to OL accumulation. These results indicate a strong connection between OL synthesis and VC0489 from V. cholerae and, for the first time, a direct regulation of an olsF homologue by the PhoBR system.
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Affiliation(s)
- Livia C Barbosa
- Laboratório de Física Biológica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carolina L Goulart
- Laboratório de Física Biológica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcela M Avellar
- Laboratório de Física Biológica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Paulo M Bisch
- Laboratório de Física Biológica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Wanda M A von Kruger
- Laboratório de Física Biológica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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Transcriptional and post-transcriptional regulation of pst2 operon expression in Vibrio cholerae O1. INFECTION GENETICS AND EVOLUTION 2017; 51:10-16. [DOI: 10.1016/j.meegid.2017.02.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 02/21/2017] [Accepted: 02/23/2017] [Indexed: 11/23/2022]
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Goulart CL, Barbosa LC, Bisch PM, von Krüger WMA. Catalases and PhoB/PhoR system independently contribute to oxidative stress resistance in Vibrio cholerae O1. MICROBIOLOGY-SGM 2016; 162:1955-1962. [PMID: 27665757 DOI: 10.1099/mic.0.000364] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
All cells are subjected to oxidative stress, a condition under which reactive oxygen species (ROS) production exceeds elimination. Bacterial defences against ROS include synthesis of antioxidant enzymes like peroxidases and catalases. Vibrio cholerae can produce two distinct catalases, KatB and KatG, which contribute to ROS homeostasis. In this study, we analysed the mechanism behind katG and katB expression in two V. cholerae O1 pandemic strains, O395 and N16961, of classical and El Tor biotypes, respectively. Both strains express these genes, especially at stationary phase. However, El Tor N16961 produces higher KatB and KatG levels and is much more resistant to peroxide challenge than the classical strain, confirming a direct relationship between catalase activity and oxidative stress resistance. Moreover, we showed that katG and katB expression levels depend on inorganic phosphate (Pi) availability, in contrast to other bacterial species. In N16961, katB and katG expression is reduced under Pi limitation relative to Pi abundance. Total catalase activity in N16961 and its phoB mutant cells was similar, independently of growth conditions, indicating that the PhoB/PhoR system is not required for katB and katG expression. However, N16961 cells from Pi-limited cultures were 50-100-fold more resistant to H2O2 challenge and accumulated less ROS than phoB mutant cells. Together, these findings suggest that, besides KatB and KatG, the PhoB/PhoR system is an important protective factor against ROS in V. cholerae N16961. They also corroborate previous results from our and other groups, suggesting that the PhoB/PhoR system is fundamental for V. cholerae biology.
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Affiliation(s)
- Carolina L Goulart
- Laboratório de Física Biológica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Livia C Barbosa
- Laboratório de Física Biológica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Paulo M Bisch
- Laboratório de Física Biológica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Wanda M A von Krüger
- Laboratório de Física Biológica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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Grillo-Puertas M, Rintoul MR, Rapisarda VA. PhoB activation in non-limiting phosphate condition by the maintenance of high polyphosphate levels in the stationary phase inhibits biofilm formation in Escherichia coli. MICROBIOLOGY-SGM 2016; 162:1000-1008. [PMID: 27023099 DOI: 10.1099/mic.0.000281] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Polyphosphate (polyP) degradation in Escherichia coli stationary phase triggers biofilm formation via the LuxS quorum sensing system. In media containing excess of phosphate (Pi), high polyP levels are maintained in the stationary phase with the consequent inhibition of biofilm formation. The transcriptional-response regulator PhoB, which is activated under Pi limitation, is involved in the inhibition of biofilm formation in several bacterial species. In the current study, we report, for the first time, we believe that E. coli PhoB can be activated in non-limiting Pi conditions, leading to inhibition of biofilm formation. In fact, PhoB was activated when high polyP levels were maintained in the stationary phase, whereas it remained inactive when the polymer was degraded or absent. PhoB activation was mediated by acetyl phosphate with the consequent repression of biofilm formation owing to the downregulation of c-di-GMP synthesis and the inhibition of autoinducer-2 production. These results allowed us to propose a model showing that PhoB is a component in the signal cascade regulating biofilm formation triggered by fluctuations of polyP levels in E. coli cells during stationary phase.
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Affiliation(s)
- M Grillo-Puertas
- Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, Chacabuco 461, T4000ILI - San Miguel de Tucumán, Tucumán, Argentina.,Instituto de Química Biológica, 'Dr Bernabe Bloj', Facultad de Bioquímica, Química y Farmacia, UNT, Chacabuco 461, T4000ILI - San Miguel de Tucumán, Tucumán, Argentina
| | - M R Rintoul
- Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, Chacabuco 461, T4000ILI - San Miguel de Tucumán, Tucumán, Argentina.,Instituto de Química Biológica, 'Dr Bernabe Bloj', Facultad de Bioquímica, Química y Farmacia, UNT, Chacabuco 461, T4000ILI - San Miguel de Tucumán, Tucumán, Argentina
| | - V A Rapisarda
- Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, Chacabuco 461, T4000ILI - San Miguel de Tucumán, Tucumán, Argentina.,Instituto de Química Biológica, 'Dr Bernabe Bloj', Facultad de Bioquímica, Química y Farmacia, UNT, Chacabuco 461, T4000ILI - San Miguel de Tucumán, Tucumán, Argentina
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Santos-Beneit F. The Pho regulon: a huge regulatory network in bacteria. Front Microbiol 2015; 6:402. [PMID: 25983732 PMCID: PMC4415409 DOI: 10.3389/fmicb.2015.00402] [Citation(s) in RCA: 235] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 04/17/2015] [Indexed: 12/15/2022] Open
Abstract
One of the most important achievements of bacteria is its capability to adapt to the changing conditions of the environment. The competition for nutrients with other microorganisms, especially in the soil, where nutritional conditions are more variable, has led bacteria to evolve a plethora of mechanisms to rapidly fine-tune the requirements of the cell. One of the essential nutrients that are normally found in low concentrations in nature is inorganic phosphate (Pi). Bacteria, as well as other organisms, have developed several systems to cope for the scarcity of this nutrient. To date, the unique mechanism responding to Pi starvation known in detail is the Pho regulon, which is normally controlled by a two component system and constitutes one of the most sensible and efficient regulatory mechanisms in bacteria. Many new members of the Pho regulon have emerged in the last years in several bacteria; however, there are still many unknown questions regarding the activation and function of the whole system. This review describes the most important findings of the last three decades in relation to Pi regulation in bacteria, including: the PHO box, the Pi signaling pathway and the Pi starvation response. The role of the Pho regulon in nutritional regulation cross-talk, secondary metabolite production, and pathogenesis is discussed in detail.
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Affiliation(s)
- Fernando Santos-Beneit
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne UK
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