Molecular Mechanisms of AhpC in Resistance to Oxidative Stress in Burkholderia thailandensis

Zhang, Bing; Gu, Huawei; Yang, Yantao; Bai, Haonan; Zhao, Chao; Si, Meiru; Su, Tao; Shen, Xihui

doi:10.3389/fmicb.2019.01483

Cited by 25 publications

(28 citation statements)

References 58 publications

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“…It is well known that the higher levels of ROS derived from antibiotics and heavy metals are the major force driving bacterial death, while a moderate level of oxidative stress has been suggested to induce antibiotic resistance in bacteria by modulating antibiotic resistance-related genes [39,40]. However, our data here demonstrated that oxidative stress is not involved in the antibiotic resistance developed through exposure to heavy metals.…”

Section: Discussioncontrasting

confidence: 78%

Reversal of heavy metal-induced antibiotic resistance by dandelion root extracts and taraxasterol

Yang¹,

Zhang

2020

Journal of Medical Microbiology

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Introduction. Metal exposure is an important factor for inducing antibiotic resistance in bacteria. Dandelion extracts have been used for centuries in traditional Chinese and Native American medicine. Aim. We assessed the effects of dandelion water extracts and taraxasterol on heavy metal-induced antibiotic resistance in Escherichia coli as well as the underlying mechanisms. Methodology. Dandelion extracts were obtained through 4 h of boiling in distilled water. Bacterial growth was monitored with a spectrophotometer. Biochemical assays were performed to assess the activities and gene transcriptions of β-lactamase and acetyltransferase. Oxidative stress was determined using an oxidation-sensitive probe, H2DCFDA. Results. The present study demonstrated that higher concentrations of nickel (>5 µg ml−1), cadmium (>0.1 µg ml−1), arsenic (>0.1 µg ml−1) and copper (>5 µg ml−1) significantly inhibited the growth of E. coli . Lower concentrations of nickel (0.5 µg ml−1), cadmium (0.05 µg ml−1) and arsenic (0.05 µg ml−1) had no effect on bacterial growth, but helped the bacteria become resistant to two antibiotics, kanamycin and ampicillin. The addition of dandelion root extracts and taraxasterol significantly reversed the antibiotic resistance induced by these heavy metals. The supplements of antibiotics and cadmium generated synergistic effects on the activities of β-lactamase and acetyltransferase (two antibiotic resistance-related proteins), which were significantly blocked by either dandelion root extract or taraxasterol. In contrast, oxidative stress was not involved in the preventative roles of dandelion root extracts and taraxasterol in heavy metal-induced antibiotic resistance. Conclusion. This study suggests that heavy metals induce bacterial antibiotic resistance and dandelion root extracts and taraxasterol could be used to help reverse bacterial resistance to antibiotics.

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Section: Discussioncontrasting

confidence: 78%

Reversal of heavy metal-induced antibiotic resistance by dandelion root extracts and taraxasterol

Yang¹,

Zhang

2020

Journal of Medical Microbiology

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“…The OxyR regulator is a LysR-like regulator that directly senses peroxide and forms intramolecular disulfide bonds that in turn lead to allosteric activation of the protein to enhance the transcription of antioxidant genes such as ahpCF, katG, ccpA, dps, oxyS [ 48 , 49 , 50 , 51 ]. In addition to its activator role, as listed for E. coli, it may also function as a repressor in other bacteria, such as Neisseria gonorrhoeae and Burkholderia thalindensis [ 23 , 52 ]. In Neisseria, OxyR acts in repression of catalase, the major anti-oxidative stress response mechanism [ 23 ].…”

Section: Discussionmentioning

confidence: 99%

Insertional Inactivation of Prevotella intermedia OxyR Results in Reduced Survival with Oxidative Stress and in the Presence of Host Cells

et al. 2021

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One of the most abundant bacteria in the subgingival pockets of patients with bleeding following mechanical periodontal therapy is Prevotella intermedia. However, despite its abundance, the molecular mechanisms of its contribution to periodontal disease are not well known. This is mainly due to the lack of genetic tools that would allow examination of the role of predicted virulence factors in the pathogenesis of this bacterium. Here, we report on the first mutant in the P. intermedia OMA14 strain. The mutation is an allelic exchange replacement of the sequences coding for a putative OxyR regulator with ermF sequences coding for the macrolide–lincosamide resistance in anaerobic bacteria. The mutant is severely impaired in its ability to grow with eukaryotic cells, indicating that it is an important target for interventional strategies. Further analyses reveal that its ability to grow with oxidative stress species, in the form of hydrogen peroxide and oxygen, is severely affected. Transcriptome analysis reveals that the major deregulated genes code for the alkylhydroperoxide reductase system, AhpCF, mediating protection from peroxide stress. Moreover, genes coding for Dps, CydA and Ftn are downregulated in the mutant strain, as further verified using qRT-PCR analysis. In conclusion, we succeeded in generating the first P. intermedia mutant and show that the OxyR-deficient strain is unable to survive with a variety of host cells as well as with oxidative stress.

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“…AhpC, an alkyl hydroperoxide reductase subunit C, belongs to the alkyl hydroperoxide reductase system, which has activity against H 2 O 2 , organic peroxides, and peroxynitrite[58]. Work in Burkholderia thailandensis suggests that AhpC is the major scavenger of H2O2 generated in the cytoplasm of this bacterium as a…”

Section: Discussionmentioning

confidence: 99%

“…Under aerobic growth, AhpC is required to prevent cell damage in S. aureus . It is a major component involved in organic-hydroperoxide resistance and scavenging H 2 O 2 [60].…”

Section: Discussionmentioning

confidence: 99%

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Comparative proteomic analysis of vancomycin-sensitive and vancomycin-intermediate resistant S. aureus

Han²,

Yang³

et al. 2021

Preprint

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The extensive use of vancomycin has led to the development of MRSA ( methicillin- resistant Staphylococcus aureus ) strains with varying degrees of resistance to vancomycin. Accumulation of surplus cell wall material, decreased cross-linking of peptidoglycan, and/ or other cell wall alterations has been put forward to explain the VISA phenotype. To our knowledge, the protein profiles of hVISA and VISA strains are rarely analyzed via quantitative comparative proteomics. In this study, we subjected subcellular fractions isolated from two isogenic S. aureus strains ( vancomycin-intermediate resistant S. aureus ) to proteomic analysis, using an integrated quantitative proteomic approach assisted by bioinformatic analysis. In total,128 up-regulated proteins ( mainly AhpC, Adh, ArgF et al.) were identified,21 down-regulated proteins ( mainly LtaS, SdrD, MsrR, MsrB, OatA et al.) were obtained. The largest group of differentially expressed proteins is composed of enzymic proteins associated with metabolic and catalytic activity, which accounts for 50% and 51% of the total proteins, respectively.Some proteins which take an indispensable part in the regulatory networks of S. aureus with vancomycin treatment are related to Cell wall metabolism ( MurA ) , Cell adhesion ( SdrC, SdrD, ClfA , ClfB ) , Proteolysis ( Atl, LytM, SceD ) and Pressure response ( MsrA , MsrB, AhpC ) process.In conclusion, our proteomic study revealed regulatory proteins associated with vancomycin resistance in S. aureus, and some of these proteins are involved in the regulation of cell metabolism and function, providing protential targets for further development of drug resistance strategies.

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Molecular Mechanisms of AhpC in Resistance to Oxidative Stress in Burkholderia thailandensis

Cited by 25 publications

References 58 publications

Reversal of heavy metal-induced antibiotic resistance by dandelion root extracts and taraxasterol

Reversal of heavy metal-induced antibiotic resistance by dandelion root extracts and taraxasterol

Insertional Inactivation of Prevotella intermedia OxyR Results in Reduced Survival with Oxidative Stress and in the Presence of Host Cells

Comparative proteomic analysis of vancomycin-sensitive and vancomycin-intermediate resistant S. aureus

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