scholarly journals Susceptibility to Antibiotics and Reactive Oxygen Species in Escherichia coli: A Survey of Clinical and Environmental Isolates

2021 ◽  
pp. 64-71
Author(s):  
Carlos F. Amábile-Cuevas ◽  
Leticia Martínez ◽  
Irma Rosas
Keyword(s):  
Oxidative Stress ◽  
Escherichia Coli ◽  
Superoxide Dismutase ◽  
Antibiotic Resistance ◽  
Cross Resistance ◽  
Bacterial Cells ◽  
Urban Dust ◽  
Beta Lactam ◽  
Gastrointestinal Infections ◽  
Selection Of

Aims: Some bacterial responses to oxidative stress also diminish antibiotic susceptibility; also, some antibiotics do increase oxidative stress within bacterial cells. Linkage or cross-resistance to prooxidants and antibiotics could facilitate the selection of antibiotic resistance and/or virulence. We made this survey in order to detect this possible linkage in Escherichia coli isolates. Methodology: The susceptibility of 102 E. coli clinical (causative of urinary or gastrointestinal infections) and environmental (rural or urban dust) isolates towards paraquat, H2O2, and antibiotics was measured using disc assays. Catalase and superoxide-dismutase (SOD) activities were measured. Results: Susceptibility to prooxidants was similar across isolates of all four sources, but urinary and urban dust isolates were more resistant to antibiotics. H2O2 "resistant" organisms had more antibiotic resistance phenotypes, particularly towards sulfadiazine and tetracycline. Paraquat "resistance" seems associated to beta-lactam resistance; but paraquat "susceptibility" seems associated to resistance towards chloramphenicol, gentamicin, ciprofloxacin and nitrofurantoin. Prooxidant disc assays correlate to catalase and superoxide-dismutase activities. A weak relationship H2O2/antibiotic-resistance, but not superoxide/antibiotic-resistance, is suggested. Conclusion: Overall, antibiotics exerting their action through oxidative stress, do not seem to have resulted in the co-selection of oxidative stress resistance, or vice versa. However, a possible link between resistance to some antibiotics and to H2O2 might contribute to co-selection between these two chemical insults.

scholarly journals Selection of a Gentamicin-Resistant Variant Following Polyhexamethylene Biguanide (PHMB) Exposure in Escherichia coli Biofilms

Antibiotics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 553
Author(s):  
Clémence Cuzin ◽  
Paméla Houée ◽  
Pierrick Lucas ◽  
Yannick Blanchard ◽  
Christophe Soumet ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Pyruvate Dehydrogenase ◽  
Parental Strain ◽  
Fold Increase ◽  
Cross Resistance ◽  
Resistant Variant ◽  
Resistance To Antibiotics ◽  
Polyhexamethylene Biguanide ◽  
Selection Of

Antibiotic resistance is one of the most important issues facing modern medicine. Some biocides have demonstrated the potential of selecting resistance to antibiotics in bacteria, but data are still very scarce and it is important to better identify the molecules concerned and the underlying mechanisms. This study aimed to assess the potential of polyhexamethylene biguanide (PHMB), a widely used biocide in a variety of sectors, to select antibiotic resistance in Escherichia coli grown in biofilms. Biofilms were grown on inox coupons and then exposed daily to sublethal concentrations of PHMB over 10 days. Antibiotic-resistant variants were then isolated and characterized phenotypically and genotypically to identify the mechanisms of resistance. Repeated exposure to PHMB led to the selection of an E. coli variant (Ec04m1) with stable resistance to gentamycin (8-fold increase in minimum inhibitory concentration (MIC) compared to the parental strain. This was also associated with a significant decrease in the growth rate in the variant. Sequencing and comparison of the parental strain and Ec04m1 whole genomes revealed a nonsense mutation in the aceE gene in the variant. This gene encodes the pyruvate dehydrogenase E1 component of the pyruvate dehydrogenase (PDH) complex, which catalyzes the conversion of pyruvate to acetyl-CoA and CO2. A growth experiment in the presence of acetate confirmed the role of this mutation in a decreased susceptibility to both PHMB and gentamicin (GEN) in the variant. This work highlights the potential of PHMB to select resistance to antibiotics in bacteria, and that enzymes of central metabolic pathways should be considered as a potential target in adaptation strategies, leading to cross-resistance toward biocides and antibiotics in bacteria.

scholarly journals Potential impact of biocide adaptation on selection of antibiotic resistance in bacterial isolates

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Engy Elekhnawy ◽  
Fatma Sonbol ◽  
Ahmed Abdelaziz ◽  
Tarek Elbanna
Keyword(s):  
Antibiotic Resistance ◽  
Cross Resistance ◽  
Main Body ◽  
Bacterial Isolates ◽  
New Agents ◽  
Biocidal Products ◽  
Potential Impact ◽  
Emergence Of Resistance ◽  
Vital Factor ◽  
Selection Of

Abstract Background Antibiotic resistance in pathogenic bacterial isolates has increased worldwide leading to treatment failures. Main body Many concerns are being raised about the usage of biocidal products (including disinfectants, antiseptics, and preservatives) as a vital factor that contributes to the risk of development of antimicrobial resistance which has many environmental and economic impacts. Conclusion Consequently, it is important to recognize the different types of currently used biocides, their mechanisms of action, and their potential impact to develop cross-resistance and co-resistance to various antibiotics. The use of biocides in medical or industrial purposes should be monitored and regulated. In addition, new agents with biocidal activity should be investigated from new sources like phytochemicals in order to decrease the emergence of resistance among bacterial isolates.

scholarly journals Survey and Sequence Characterization of Bovine Mastitis-Associated Escherichia coli in Dairy Herds

2020 ◽  
Vol 7 ◽  
Author(s):  
John I. Alawneh ◽  
Ben Vezina ◽  
Hena R. Ramay ◽  
Hulayyil Al-Harbi ◽  
Ameh S. James ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Bovine Mastitis ◽  
Antibiotic Resistance Genes ◽  
Tetracycline Resistance ◽  
Sequence Type ◽  
Genotypic Differences ◽  
Beta Lactam ◽  
Sequence Characterization ◽  
E Coli

Escherichia coli is frequently associated with mastitis in cattle. “Pathogenic” and “commensal” isolates appear to be genetically similar. With a few exceptions, no notable genotypic differences have been found between commensal and mastitis-associated E. coli. In this study, 24 E. coli strains were isolated from dairy cows with clinical mastitis in three geographic regions of Australia (North Queensland, South Queensland, and Victoria), sequenced, then genomically surveyed. There was no observed relationship between sequence type (ST) and region (p = 0.51). The most common Multi Locus Sequence Type was ST10 (38%), then ST4429 (13%). Pangenomic analysis revealed a soft-core genome of 3,463 genes, including genes associated with antibiotic resistance, chemotaxis, motility, adhesion, biofilm formation, and pili. A total of 36 different plasmids were identified and generally found to have local distributions (p = 0.02). Only 2 plasmids contained antibiotic resistance genes, a p1303_5-like plasmid encoding multidrug-resistance (trimethoprim, quaternary ammonium, beta-lactam, streptomycin, sulfonamide, and kanamycin) from two North Queensland isolates on the same farm, while three Victorian isolates from the same farm contained a pCFSAN004177P_01-like plasmid encoding tetracycline-resistance. This pattern is consistent with a local spread of antibiotic resistance through plasmids of bovine mastitis cases. Notably, co-occurrence of plasmids containing virulence factors/antibiotic resistance with putative mobilization was rare, though the multidrug resistant p1303_5-like plasmid was predicted to be conjugative and is of some concern. This survey has provided greater understanding of antibiotic resistance within E. coli-associated bovine mastitis which will allow greater prediction and improved decision making in disease management.

Synechocystis Fe superoxide dismutase gene confers oxidative stress tolerance to Escherichia coli

2004 ◽  
Vol 316 (2) ◽  
pp. 540-544 ◽  
Author(s):  
Jyotirmoy Bhattacharya ◽  
Krishnarup GhoshDastidar ◽  
Anirban Chatterjee ◽  
Manoj Majee ◽  
Arun Lahiri Majumder
Keyword(s):  
Oxidative Stress ◽  
Escherichia Coli ◽  
Superoxide Dismutase ◽  
Stress Tolerance ◽  
Oxidative Stress Tolerance ◽  
Superoxide Dismutase Gene

Effects of Oxidative Compounds on Thermotolerance in Escherichia coli O157:H7 Strains EO139 and 380-94

2005 ◽  
Vol 68 (11) ◽  
pp. 2443-2446 ◽  
Author(s):  
ISABEL C. BLACKMAN ◽  
YOUNG W. PARK ◽  
MARK A. HARRISON
Keyword(s):  
Oxidative Stress ◽  
Escherichia Coli ◽  
Ascorbic Acid ◽  
Lethal Effect ◽  
Iron Chloride ◽  
Plate Count ◽  
Escherichia Coli O157 ◽  
Bacterial Cells ◽  
E Coli ◽  
Chloride Hexahydrate

An oxidative complex composed of ferric iron chloride hexahydrate, ADP, and ascorbic acid can generate hydrogen peroxide and hydroxyl radicals in fibroblasts. These compounds are naturally found in meat and meat-based products and may elicit oxidative stress on Escherichia coli O157:H7, thus conferring thermotolerance to the bacterium due to the phenomenon of the global stress response. The effect of the levels of the oxidative complex on the thermotolerance of E. coli O157:H7 was investigated. Cultures of E. coli O157:H7 strains EO139 and 380-94 were mixed in three different concentrations (10:10: 40, 15:15:60, and 20:20:80 μM) of the oxidative complex (iron III chloride, ADP, and ascorbic acid, respectively). The samples were inserted into capillary tubes and heated in a circulating water bath at 59 and 60°C for EO139 and 380-94, respectively. Tubes were removed at intervals of 5 min for up to 1 h and contents spirally plated on plate count agar that was incubated for 48 h at 37°C. The thermotolerance of both E. coli O157:H7 strains EO139 and 380-94 was influenced by the concentrations of the oxidative complex. The ratio of 10:10:40 μM enhanced thermotolerance of EO139 and 390-94 at 59 and 60°C, respectively. However, exposure to the ratios of 15:15:60 and 20:20:80 μM rendered the pathogen more sensitive to the lethal effect and did not enhance the thermotolerance of the cells. The significance of this study is twofold. This experiment proves that oxidative stress can enhance thermotolerance of bacterial cells induced by an oxidative complex if only in a specific ratio and concentration. It is possible to speculate that if the chemical compounds are present in this ratio in meats, they may enhance the thermal resistance of E. coli O157:H7 and make the bacteria more difficult to eliminate, thus increasing the risk of foodborne illness in consumers.

scholarly journals Genetic Investigation of Beta-Lactam Associated Antibiotic Resistance Among Escherichia Coli Strains Isolated from Water Sources

2017 ◽  
Vol 11 (1) ◽  
pp. 203-210 ◽  
Author(s):  
Reza Ranjbar ◽  
Mehrdad Sami
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Surface Water ◽  
Water Resources ◽  
Water Sources ◽  
Resistant Bacteria ◽  
Beta Lactam ◽  
E Coli ◽  
Surface Water Resources ◽  
Extended Spectrum Beta Lactamases

Background: Antimicrobial resistance is an important factor threatening human health. It is widely accepted that antibiotic resistant bacteria such as Escherichia coli (E. coli) released from humans and animals into the water sources, can introduce their resistance genes into the natural bacterial community. Objective: The aim of this study was to investigate the prevalence of blaTEM, blaCTX, blaSHV, blaOXA and blaVEB associated-antibiotic resistance among E. coli bacteria isolated from different water resources in Iran. Methods: The study contained all E. coli strains segregated from different surface water sources. The Kirby-Bauer method and combined discs method was determined in this study for testing antimicrobial susceptibility and strains that produced Extended-Spectrum Beta Lactamases (ESBL), respectively. DNA extraction kit was applied for genomic and plasmid DNA derivation. Finally the frequency of resistant genes including blaTEM, blaCTX, blaSHV, blaOXA and blaVEB in ESBL producing isolates were studied by PCR. Results: One hundred E. coli strains were isolated and entered in the study. The highest antibiotic resistance was observed on clindamycin (96%). Moreover, 38.5% isolates were ESBL producers. The frequency of different ESBLs genes were 37%, 27%, 27%, and 25% for blaTEM, blaCTX, blaSHV, and blaOXA, respectively. The blaVEB wasn’t found in any isolates. Conclusion: The study revealed a high prevalence of CTX-M, TEM, SHV and OXA genes among E. coli strains in surface water resources. In conclusion, these results raised a concern regarding the presence and distribution of these threatening factors in surface water sources and its subsequent outcomes.

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