scholarly journals Overexpression of the Escherichia coli sugE Gene Confers Resistance to a Narrow Range of Quaternary Ammonium Compounds

2002 ◽  
Vol 184 (9) ◽  
pp. 2543-2545 ◽  
Author(s):  
Yong Joon Chung ◽  
Milton H. Saier
Keyword(s):  
Escherichia Coli ◽  
Drug Resistance ◽  
Multidrug Resistance ◽  
Quaternary Ammonium ◽  
Narrow Range ◽  
Quaternary Ammonium Compounds ◽  
High Level Expression ◽  
Small Multidrug Resistance ◽  
High Level ◽  
Ammonium Compounds

ABSTRACT SugE of Escherichia coli, first identified as a suppressor of groEL mutations but a member of the small multidrug resistance family, has not previously been shown to confer a drug resistance phenotype. We show that high-level expression of sugE leads to resistance to a subset of toxic quaternary ammonium compounds.

BACTERIOLOGICAL EVALUATION OF QUATERNARY AMMONIUM COMPOUNDS ALONE AND IN DETERGENT FORMULATIONS

1953 ◽  
Vol 16 (4) ◽  
pp. 186-188 ◽  
Author(s):  
T. W. Humphreys ◽  
C. K. Johns
Keyword(s):  
Escherichia Coli ◽  
Low Temperature ◽  
Quaternary Ammonium ◽  
Test Organism ◽  
Water Hardness ◽  
Quaternary Ammonium Compounds ◽  
Glass Slide ◽  
Detergent Product ◽  
Bacteriological Evaluation ◽  
Ammonium Compounds

Using Escherichia coli as test organism, three quaternary detergent-sanitizers and their constituent QACs were evaluated by modified glass slide and Weber and Black methods at 5°, 20°, and 45°C in artificial hard and distilled waters. QAC activity was reduced by low temperature and water hardness, the latter exerting the greater effect. Each detergent product was more effective than its constituent QAC component alone. Reasons for the earlier endpoints obtained with glass slide method are discussed.

VARIATIONS IN THE CHARACTERISTICS OF E. COLI INDUCED BY QUATERNARY AMMONIUM COMPOUNDS

1951 ◽  
Vol 14 (4) ◽  
pp. 138-141 ◽  
Author(s):  
C. Kenneth Crocker
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Induced Resistance ◽  
Quaternary Ammonium ◽  
Quaternary Ammonium Compounds ◽  
Liquid Media ◽  
E Coli ◽  
Metallic Sheen ◽  
Small Colony ◽  
Ammonium Compounds

Escherichia coli lost the ability to produce gas in liquid media and formed atypical small colony variants on desoxycholate agar, concurrent with induced resistance to quaternary ammonium compounds. Paralleling high resistance, the metallic sheen of colonies on confirmatory medium did not appear. The variant strains showed a decrease in growth rate, failed to reduce methylene blue, and were unable to ferment normal sugars. Thus, with induced resistance, variations occurred in Escherechia coli such as to reduce the value of coliform tests used to identify its presence.

scholarly journals Crystal structures of bacterial Small Multidrug Resistance transporter EmrE in complex with structurally diverse substrates

2022 ◽  
Author(s):  
Ali A Kermani ◽  
Olive E. Burata ◽  
B Ben Koff ◽  
Akiko Koide ◽  
Shohei Koide ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Binding Site ◽  
Quaternary Ammonium ◽  
Structural Information ◽  
Structural Description ◽  
Small Multidrug Resistance ◽  
Novel Approach ◽  
Backbone Structure ◽  
Multidrug Resistance Transporter ◽  
Ammonium Compounds

Proteins from the bacterial small multidrug resistance (SMR) family are proton-coupled exporters of diverse antiseptics and antimicrobials, including polyaromatic cations and quaternary ammonium compounds. The transport mechanism of the Escherichia coli transporter, EmrE, has been studied extensively, but a lack of high-resolution structural information has impeded a structural description of its molecular mechanism. Here we apply a novel approach, multipurpose crystallization chaperones, to solve several structures of EmrE, including a 2.9 Å structure at low pH without substrate. We report five additional structures in complex with structurally diverse transported substrates, including quaternary phosphonium, quaternary ammonium, and planar polyaromatic compounds. These structures show that binding site tryptophan and glutamate residues adopt different rotamers to conform to disparate structures without requiring major rearrangements of the backbone structure. Structural and functional comparison to Gdx-Clo, an SMR protein that transports a much narrower spectrum of substrates, suggests that in EmrE, a relatively sparse hydrogen bond network among binding site residues permits increased sidechain flexibility.

scholarly journals Molecular mechanisms of higher MICs of antibiotics and quaternary ammonium compounds for Escherichia coli isolated from bacteraemia

2012 ◽  
Vol 67 (12) ◽  
pp. 2837-2842 ◽  
Author(s):  
S. Buffet-Bataillon ◽  
A. Le Jeune ◽  
S. Le Gall-David ◽  
M. Bonnaure-Mallet ◽  
A. Jolivet-Gougeon
Keyword(s):  
Escherichia Coli ◽  
Quaternary Ammonium ◽  
Molecular Mechanisms ◽  
Quaternary Ammonium Compounds ◽  
Ammonium Compounds

scholarly journals Genetic basis of resistance to quaternary ammonium compounds – the qac genes and their role: a review

2012 ◽  
Vol 57 (No. 6) ◽  
pp. 275-281 ◽  
Author(s):  
Z. Jaglic ◽  
D. Cervinkova
Keyword(s):  
Quaternary Ammonium ◽  
Genetic Basis ◽  
Current Knowledge ◽  
Quaternary Ammonium Compounds ◽  
Practical Significance ◽  
Multidrug Resistance Proteins ◽  
Resistance Proteins ◽  
Small Multidrug Resistance ◽  
Cationic Compounds ◽  
Ammonium Compounds

 Although the qac genes are named after one of their main substrates (i.e., quaternary ammonium compounds), these genes also code for resistance to a broad spectrum of other cationic compounds such as intercalating dyes, diamidines and biguanides. The various Qac proteins are involved in relatively low specific efflux-based multidrug pumps and belong to a family of small multidrug resistance proteins. Even though the practical significance of qac-mediated resistance lies mainly in resistance to antiseptics, contradictory findings on this issue are still reported. Therefore, the aim of this review is to summarise the current knowledge on qac-mediated resistance with special emphasis on resistance to antiseptics and its relevance for practice.  

scholarly journals Quaternary ammonium compounds: an alternative disinfection method for fresh produce wash water

2007 ◽  
Vol 5 (2) ◽  
pp. 329-333 ◽  
Author(s):  
Cristobal Chaidez ◽  
Javier Lopez ◽  
Nohelia Castro-del Campo
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Quaternary Ammonium ◽  
Fruits And Vegetables ◽  
Fresh Produce ◽  
Quaternary Ammonium Compounds ◽  
Wash Water ◽  
Worst Case ◽  
Average Case ◽  
Ammonium Compounds

Irrigation water can serve as a vehicle for transporting pathogenic microorganisms, and numerous cases of bacterial infections from consumption of irrigated fresh produce have been reported in recent years. Chlorine-based disinfectants applied when produce is packed are widely used to control microorganisms. When applied properly, the chlorine products are effective. However, hazardous disinfection breakdown products can be formed, and chlorine disinfectants have high oxidant activity that can affect produce quality and pose a risk to food handlers. Quaternary Ammonium Compounds (QACs) are a disinfectant alternative for the washing of fruits and vegetables. They can control a great number of microorganisms, have low toxicity when used at recommended doses, and are stable in storage. The purpose of this work was to assess the disinfectant activity of QACs against Escherichia coli and Staphylococcus aureus under worst-case and average-case turbidity conditions, (2 and 100 nephelometric units); two disinfectant concentrations (100 and 200 mg/L; and two contact times (30 and 120 seconds). Our research showed that QACs were effective against both bacteria. The percentage reduction of Escherichia coli was significantly higher in the less turbid solution (P=0.027), while turbidity did not affect the reduction of Staphylococcus aureus (P>0.05). E. coli was more resistant to QAC treatment than S. aureus. Based on the data obtained we can conclude that QACs could be an alternative in washing processes of fruits and vegetables.

scholarly journals Phenotypic and multi-omics characterization of Escherichia coli K-12 adapted to quaternary ammonium compounds identifies lipid A and cell envelope alterations regulated by mar-sox-rob and stress inducible pathways

2020 ◽  
Author(s):  
Kari A.C. Green ◽  
Branden S.J. Gregorchuk ◽  
Shelby L. Reimer ◽  
Nicola H. Cartwright ◽  
Daniel R. Beniac ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Quaternary Ammonium ◽  
Lipid A ◽  
Quaternary Ammonium Compounds ◽  
Cross Resistance ◽  
E Coli ◽  
Lipid A Biosynthesis ◽  
K 12 ◽  
Ammonium Compounds

AbstractQuaternary ammonium compounds (QACs) benzalkonium (BZK) and cetrimide (CET) are common disinfectants used to inhibit or eradicate Gram-negative bacteria in clinical and agricultural products. QAC tolerance in Escherichia coli and other Enterobacterales species can confer cross-resistance to various clinically used antibiotics, making it important to understand mechanisms of QAC tolerance in greater depth. QAC adaptation by E. coli is hypothesized to alter MarRAB regulated genes that converge on the outer membrane, specifically, lipid A biosynthesis and transport genes, porins, and efflux pump systems. To test this, we performed a ‘multi’-omics and phenotypic characterization of E. coli K-12 adapted to BZK and CET, to assess how QACs alter cell growth, genomics, and proteomics. E. coli adapted to either BZK and CET resulted in strains with stable QAC tolerance when either drug was omitted, elongated and narrower cell morphologies by scanning electron microscopy, and reduced growth fitness when compared to un-adapted E. coli. Antimicrobial susceptibility testing revealed that QAC adaptation increased E. coli tolerance by ≥4-fold to BZK, CET, and other QACs but no antibiotic cross-resistance. Single nucleotide variants identified by whole genome sequencing and differentially accumulated proteins by liquid chromatography-mass spectrometry identified alterations to various QAC-adapted E. coli genes and proteins belonging to: lipid A biosynthesis and transport (lpxLM, msbA, mla), the mar-sox-rob regulatory pathway (marR, rob), DNA/protein translation (gyrA, rpsA, rpoB, rapA). These alterations validate the hypothesis that mar-sox-rob network plays a role in QAC tolerance and identifies additional stress inducible genetic and protein QAC tolerant biomarkers.ImportanceBacterial tolerance mechanisms associated with disinfectant QAC adaptation is hypothesized to overlap with the mar-sox-rob multiple antimicrobial resistance pathway but has not been directly shown. Here, we generate QAC tolerant E. coli strains and identify phenotypic changes associated with protein and genetic alterations caused by prolonged QAC exposure. We identified genes that overlap with known antibiotic resistance mechanisms as well as distinct genes and proteins specific to QAC adaptation that are useful for future bacterial disinfectant tolerance mechanism studies. However, these altered genes and proteins implicate MarR and Rob pathways specifically in QAC tolerance but, surprisingly, the involvement of mar-sox-rob pathways did not increase antibiotic cross-resistance. Many altered genes we identified were essential genes in lipid A biosynthesis/transport, DNA and RNA transcription, and protein regulation systems potentially explaining why only QAC cross-tolerance was observed and why we observed greater cell fitness costs despite MarR and Rob pathway involvement.

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