The major facilitator superfamily transporter MdtM contributes to the intrinsic resistance of Escherichia coli to quaternary ammonium compounds

2012 ◽  
Vol 68 (4) ◽  
pp. 831-839 ◽  
Author(s):  
S. R. Holdsworth ◽  
C. J. Law
1953 ◽  
Vol 16 (4) ◽  
pp. 186-188 ◽  
Author(s):  
T. W. Humphreys ◽  
C. K. Johns

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.


1951 ◽  
Vol 14 (4) ◽  
pp. 138-141 ◽  
Author(s):  
C. Kenneth Crocker

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.


2002 ◽  
Vol 184 (9) ◽  
pp. 2543-2545 ◽  
Author(s):  
Yong Joon Chung ◽  
Milton H. Saier

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.


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

2006 ◽  
Vol 188 (3) ◽  
pp. 977-987 ◽  
Author(s):  
Iman Chouikha ◽  
Pierre Germon ◽  
Annie Brée ◽  
Philippe Gilot ◽  
Maryvonne Moulin-Schouleur ◽  
...  

ABSTRACT The complete nucleotide sequence and genetic organization of a new genomic island (AGI-3) isolated from the extraintestinal avian pathogenic Escherichia coli strain BEN2908 is reported. This 49,600-bp island is inserted at the selC locus and contains putative mobile genetic elements such as a phage-related integrase gene, transposase genes, and direct repeats. AGI-3 shows a mosaic structure of five modules. Some of these modules are present in other E. coli strains and in other pathogenic bacterial species. The gene cluster aec-35 to aec-37 of module 1 encodes proteins associated with carbohydrates assimilation such as a major facilitator superfamily transporter (Aec-36), a glycosidase (Aec-37), and a putative transcriptional regulator of the LacI family (Aec-35). The aec-35 to aec-37 cluster was found in 11.6% of the tested pathogenic and nonpathogenic E. coli strains. When present, the aec-35 to aec-37 cluster is strongly associated with the selC locus (97%). Deletion of the aec-35-aec-37 region affects the assimilation of seven carbohydrates, decreases the growth rate of the strain in minimal medium containing galacturonate or trehalose, and attenuates the virulence of E. coli BEN2908 for chickens.


2007 ◽  
Vol 5 (2) ◽  
pp. 329-333 ◽  
Author(s):  
Cristobal Chaidez ◽  
Javier Lopez ◽  
Nohelia Castro-del Campo

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.


2020 ◽  
Author(s):  
Kari A.C. Green ◽  
Branden S.J. Gregorchuk ◽  
Shelby L. Reimer ◽  
Nicola H. Cartwright ◽  
Daniel R. Beniac ◽  
...  

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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