Faculty Opinions recommendation of Assessment of Insertion Sequence Mobilization as an Adaptive Response to Oxidative Stress in Acinetobacter baumannii Using IS-seq.

2017 ◽  
Author(s):  
Fred Dyda
Keyword(s):  
Oxidative Stress ◽  
Acinetobacter Baumannii ◽  
Adaptive Response ◽  
Insertion Sequence

scholarly journals Assessment of Insertion Sequence Mobilization as an Adaptive Response to Oxidative Stress in Acinetobacter baumannii Using IS-seq

2017 ◽  
Vol 199 (9) ◽  
Author(s):  
Meredith S. Wright ◽  
Stephanie Mountain ◽  
Karen Beeri ◽  
Mark D. Adams
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Hydrogen Peroxide ◽  
Acinetobacter Baumannii ◽  
Insertion Sequence ◽  
Iron Homeostasis ◽  
Bacterial Species ◽  
Growth Conditions ◽  
Content Type ◽  
Is Elements

ABSTRACT Insertion sequence (IS) elements are found throughout bacterial genomes and contribute to genome variation by interrupting genes or altering gene expression. Few of the more than 30 IS elements described in Acinetobacter baumannii have been characterized for transposition activity or expression effects. A targeted sequencing method, IS-seq, was developed to efficiently map the locations of new insertion events in A. baumannii genomes and was used to identify novel IS sites following growth in the presence of hydrogen peroxide, which causes oxidative stress. Serial subculture in the presence of subinhibitory concentrations of hydrogen peroxide led to rapid selection of cells carrying an ISAba1 element upstream of the catalase-peroxidase gene katG. Several additional sites for the elements ISAba1, ISAba13, ISAba25, ISAba26, and ISAba125 were found at low abundance after serial subculture, indicating that each element is active and contributes to genetic variation that may be subject to selection. Following hydrogen peroxide exposure, rapid changes in gene expression were observed in genes related to iron homeostasis. The IS insertions adjacent to katG resulted in more than 20-fold overexpression of the gene and increased hydrogen peroxide tolerance. IMPORTANCE Insertion sequences (IS) contribute to genomic and phenotypic variation in many bacterial species, but little is known about how transposition rates vary among elements or how selective pressure influences this process. A new method for identifying new insertion locations that arise under experimental growth conditions in the genome, termed IS-seq, was developed and tested with cells grown in the presence of hydrogen peroxide, which causes oxidative stress. Gene expression changes in response to hydrogen peroxide exposure are similar to those observed in other species and include genes that control free iron concentrations. New IS insertions adjacent to a gene encoding a catalase enzyme confirm that IS elements can rapidly contribute to adaptive variation in the presence of selection.

scholarly journals How N-Acetylcysteine Supplementation Affects Redox Regulation, Especially at Mitohormesis and Sarcohormesis Level: Current Perspective

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 153
Author(s):  
Aslı Devrim-Lanpir ◽  
Lee Hill ◽  
Beat Knechtle
Keyword(s):  
Oxidative Stress ◽  
Oxidative Metabolism ◽  
Adaptive Response ◽  
Redox Regulation ◽  
Therapeutic Agent ◽  
Metabolic Effects ◽  
Metabolic Adaptations ◽  
Current Perspective ◽  
Exercise Induced ◽  
Response To Exercise

Exercise frequently alters the metabolic processes of oxidative metabolism in athletes, including exposure to extreme reactive oxygen species impairing exercise performance. Therefore, both researchers and athletes have been consistently investigating the possible strategies to improve metabolic adaptations to exercise-induced oxidative stress. N-acetylcysteine (NAC) has been applied as a therapeutic agent in treating many diseases in humans due to its precursory role in the production of hepatic glutathione, a natural antioxidant. Several studies have investigated NAC’s possible therapeutic role in oxidative metabolism and adaptive response to exercise in the athletic population. However, still conflicting questions regarding NAC supplementation need to be clarified. This narrative review aims to re-evaluate the metabolic effects of NAC on exercise-induced oxidative stress and adaptive response developed by athletes against the exercise, especially mitohormetic and sarcohormetic response.

scholarly journals Vitamin C Recycling Is Enhanced in the Adaptive Response to Leptin-Induced Oxidative Stress in Keratinocytes

2003 ◽  
Vol 121 (4) ◽  
pp. 786-793 ◽  
Author(s):  
Isabella Savini ◽  
Maria Valeria Catani ◽  
Antonello Rossi ◽  
Guglielmo Duranti ◽  
Marco Ranalli ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Vitamin C ◽  
Adaptive Response

AROS-29 is involved in adaptive response to oxidative stress

2006 ◽  
Vol 40 (5) ◽  
pp. 467-476 ◽  
Author(s):  
Nicola Montesano Gesualdi ◽  
Giuseppa Chirico ◽  
Maria Teresa Catanese ◽  
Giuseppe Pirozzi ◽  
Franca Esposito
Keyword(s):  
Oxidative Stress ◽  
Adaptive Response

scholarly journals Insights into the Periplasmic Proteins of Acinetobacter baumannii AB5075 and the Impact of Imipenem Exposure: A Proteomic Approach

2019 ◽  
Vol 20 (14) ◽  
pp. 3451 ◽  
Author(s):  
Scribano ◽  
Marzano ◽  
Mortera ◽  
Sarshar ◽  
Vernocchi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Protein Interactions ◽  
Biological Response ◽  
Bacterial Viability ◽  
Proteomic Approach ◽  
Periplasmic Proteins ◽  
General Response ◽  
The Impact

Carbapenem-resistant Acinetobacter baumannii strains cause life-threatening infections due to the lack of therapeutic options. Although the main mechanisms underlying antibiotic-resistance have been extensively studied, the general response to maintain bacterial viability under antibiotic exposure deserves to be fully investigated. Since the periplasmic space contains several proteins with crucial cellular functions, besides carbapenemases, we decided to study the periplasmic proteome of the multidrug-resistant (MDR) A. baumannii AB5075 strain, grown in the absence and presence of imipenem (IMP). Through the proteomic approach, 65 unique periplasmic proteins common in both growth conditions were identified: eight proteins involved in protein fate, response to oxidative stress, energy metabolism, antibiotic-resistance, were differentially expressed. Among them, ABUW_1746 and ABUW_2363 gene products presented the tetratricopeptide repeat motif, mediating protein-protein interactions. The expression switch of these proteins might determine specific protein interactions to better adapt to changing environmental conditions. ABUW_2868, encoding a heat shock protein likely involved in protection against oxidative stress, was upregulated in IMP-exposed bacteria. Accordingly, the addition of periplasmic proteins from A. baumannii cultured with IMP increased bacterial viability in an antioxidant activity assay. Overall, this study provides the first insights about the composition of the periplasmic proteins of a MDR A. baumannii strain, its biological response to IMP and suggests possible new targets to develop alternative antibiotic drugs.

scholarly journals Clonal diversity of Acinetobacter baumannii from diabetic patients in Saudi Arabian hospitals

2014 ◽  
Vol 63 (11) ◽  
pp. 1460-1466 ◽  
Author(s):  
Abdulrahman A. Alsultan ◽  
Elsayed Aboulmagd ◽  
Benjamin A. Evans ◽  
Sebastian G. B. Amyes
Keyword(s):  
Health Care ◽  
Saudi Arabia ◽  
Acinetobacter Baumannii ◽  
Insertion Sequence ◽  
Clonal Diversity ◽  
Diabetic Patients ◽  
Major Health ◽  
Intensive Care Patients ◽  
Carbapenem Resistant ◽  
Vitek 2

Carbapenem-resistant Acinetobacter baumannii (CR-AB) represents a major health-care problem, causing high rates of morbidity and mortality. This study investigated the clonality of CR-AB isolated from diabetic patients from different regions in Saudi Arabia, as well as the relatedness of the β-lactamase genes. A total of 64 non-repetitive CR-AB clinical isolates were collected from 16 different regions in Saudi Arabia from intensive care patients. Isolates were identified phenotypically by the Vitek 2 compact system and genotypically by amplification of the bla OXA-51-like gene. The target sequences were amplified by PCR and the clonal diversity of the isolates was explored by PFGE. Resistance studies revealed that the prevalence of imipenem and meropenem resistance was 92 % and 96 %, respectively, while the vast majority of the isolates were susceptible to tigecycline and colistin. In addition, bla VIM and bla OXA-23 were the most prevalent genes in the isolates under investigation, while ISAba1 was the most dominant insertion sequence. PFGE results showed 13 clusters; clone H was dominant, comprising 20 isolates from four hospitals, followed by clones C and F, comprising 11 isolates each from three and six hospitals, respectively. Moreover, the current study signified the clonal diversity of CR-AB in Saudi Arabia and showed the ability of some clones to infect patients in many different cities.

scholarly journals Carbapenemase Production of Clinical Isolates Acinetobacter baumannii and Pseudomonas aeruginosa from a Bulgarian University Hospital

Folia Medica ◽  
2017 ◽  
Vol 59 (4) ◽  
pp. 413-422 ◽  
Author(s):  
Atanaska P. Petrova ◽  
Irina D. Stanimirova ◽  
Ivan N. Ivanov ◽  
Michael M. Petrov ◽  
Tsonka M. Miteva-Katrandzhieva ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Acinetobacter Baumannii ◽  
Insertion Sequence ◽  
Susceptibility Testing ◽  
Transmembrane Protein ◽  
Carbapenem Resistance ◽  
University Hospital ◽  
Gram Negative ◽  
Main Factors ◽  
Hospital Wards

AbstractBackground: Production of Bla OXA-23, OXA-24, OXA-58 and hyperexpression of OXA-51 due to ISAba1 insertion sequence are the leading causes of carbapenem resistance in Acinetobacter baumannii. The loss of OprD transmembrane protein and the overexpression of some effl ux pumps are considered to be the main factors for carbapenem resistance in Pseudomonas aeruginosa whereas metallo-enzymes’ production has a secondary role. Aim: Тo examine the carbapenem resistance due to carbapenemase production among clinically signifi cant Gram-negative non-fermenters from St George University hospital, Plovdiv: A. baumannii and P. aeruginosa. Materials and methods: Forty three A. baumannii and 43 P. aeruginosa isolates, resistant or with intermediate resistance to imipenem and/or meropenem were included in the study. They were collected from patients admitted in 14 various hospital wards between 2010 and 2014. Both phenotypic and genetic methods were used for identifi cation and antimicrobial susceptibility testing. Results: All A. baumannii demonstrated carbapenemase production determined by a modifi ed Hodge test whereas P. aeruginosa isolates did not show this phenomenon. OXA-23 genes were determined in 97.7% (42 out of 43) of A. baumannii isolates indistinguishable from the sequence of the classical ARI-1 gene. OXA-24, OXA-58 and overexpression of OXA-51 were not registered in any of the isolates. All P. aeruginosa were negative for blaVIM and blaIMP genes. Conclusion: The leading cause of carbapenem resistance in A. baumannii isolates from our hospital is the carbapenemase production due to the expression of OXA- 23 gene, whereas in P. aeruginosa - the loss of transmembrane OprD protein and the effl ux pumps’ hyperexpression are suspected to be the main mechanisms.

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