scholarly journals Exposure to Sub-lethal 2,4-Dichlorophenoxyacetic Acid Arrests Cell Division and Alters Cell Surface Properties in Escherichia coli

2018 ◽  
Vol 9 ◽  
Author(s):  
Supriya V. Bhat ◽  
Belma Kamencic ◽  
André Körnig ◽  
Zinnat Shahina ◽  
Tanya E. S. Dahms
2009 ◽  
Vol 72 (8) ◽  
pp. 1699-1704 ◽  
Author(s):  
SUPAYANG PIYAWAN VORAVUTHIKUNCHAI ◽  
SAKOL SUWALAK

The effects of Quercus infectoria (family Fagaceae) nutgalls on cell surface properties of Shiga toxigenic Escherichia coli (STEC) were investigated with an assay of microbial adhesion to hydrocarbon. The surface of bacterial cells treated with Q. infectoria exhibited a higher level of cell surface hydrophobicity (CSH) toward toluene than did the surface of untreated cells. With 50% ethanolic extract, the CSH of the three strains of STEC O157:H7 treated with 4× MIC of the extract resulted in moderate or strong hydrophobicity, whereas at 2× MIC and MIC, the CSH of only one strain of E. coli O157:H7 was significantly affected. The 95% ethanolic extract had a significant effect on CSH of all three strains at both 4× MIC and 2× MIC but not at the MIC. The effect on bacterial CSH was less pronounced with the other STEC strains. At 4× MIC, the 50% ethanolic extract increased the CSH of all non-O157 STEC strains significantly. At 2× MIC and 4× MIC, the 95% ethanolic extract affected the CSH of E. coli O26:H11 significantly but did not affect E. coli O111:NM or E. coli O22. Electron microscopic examination revealed the loss of pili in the treated cells. The ability of Q. infectoria extract to modify hydrophobic domains enables this extract to partition the lipids of the bacterial cell membrane, rendering the membrane more permeable and allowing leakage of ions and other cell contents, which leads to cell death. Further studies are required to evaluate the effects of Q. infectoria extract in food systems or in vivo and provide support for the use of this extract as a food additive for control of these STEC pathogens.


Author(s):  
Astghik Pepoyan ◽  
Marine Balayan ◽  
Anahit Manvelyan ◽  
Marianna Isajanyan ◽  
Vardan Tsaturyan ◽  
...  

1999 ◽  
Vol 123 (3) ◽  
pp. 413-421 ◽  
Author(s):  
J. SPENCER ◽  
H. R. SMITH ◽  
H. CHART

Twenty-two strains of enteroaggregative Escherichia coli (EAggEC), isolated from four outbreaks of diarrhoeal disease in England, were examined for a range of phenotypic attributes including the ability to produce fimbriae, haemolysins and siderophores, and cell-surface properties such as surface charge and hydrophobicity. Strains of EAggEC isolated from two of these outbreaks belonged to a diverse range of serotypes and were heterogeneous in phenotype. Strains of EAggEC isolated from the other two outbreaks belonged predominantly to serotypes O86[ratio ]H34 and O98[ratio ]H-, respectively. Only two strains expressed fimbriae and two strains produced an 18 kDa membrane associated protein (MAP), suggesting that EAggEC express a range of adhesion mechanisms to produce the cell arrangement recognized as the ‘stacked brick’ formation. The possible explanation for the diversity of EAggEC serotypes is discussed.


1992 ◽  
Vol 174 (8) ◽  
pp. 2525-2538 ◽  
Author(s):  
C T Parker ◽  
A W Kloser ◽  
C A Schnaitman ◽  
M A Stein ◽  
S Gottesman ◽  
...  

2019 ◽  
Vol 7 (6) ◽  
pp. 172 ◽  
Author(s):  
Rabiul Islam ◽  
Shyretha Brown ◽  
Ali Taheri ◽  
C. Korsi Dumenyo

Pectobacterium carotovorum is a gram-negative bacterium that, together with other soft rot Enterobacteriaceae causes soft rot disease in vegetables, fruits, and ornamental plants through the action of exoproteins including plant cell wall-degrading enzymes (PCWDEs). Although pathogenicity in these bacteria is complex, virulence levels are proportional to the levels of plant cell wall-degrading exoenzymes (PCWDEs) secreted. Two low enzyme-producing transposon Tn5 mutants were isolated, and compared to their parent KD100, the mutants were less virulent on celery petioles and carrot disks. The inactivated gene responsible for the reduced virulence phenotype in both mutants was identified as wcaG. The gene, wcaG (previously denoted fcl) encodes NAD-dependent epimerase/dehydratase, a homologue of GDP-fucose synthetase of Escherichia coli. In Escherichia coli, GDP-fucose synthetase is involved in the biosynthesis of the exopolysaccharide, colanic acid (CA). The wcaG mutants of P. carotovorum formed an enhanced level of biofilm in comparison to their parent. In the hydrophobicity test the mutants showed more hydrophobicity than the parent in hexane and hexadecane as solvents. Complementation of the mutants with extrachromosomal copies of the wild type gene restored these functions to parental levels. These data indicate that NAD-dependent epimerase/dehydratase plays a vital rule in cell surface properties, exoenzyme production, and virulence in P. carotovorum.


Anaerobe ◽  
2014 ◽  
Vol 28 ◽  
pp. 212-215 ◽  
Author(s):  
Valérie Andriantsoanirina ◽  
Anne-Claire Teolis ◽  
Liu Xin Xin ◽  
Marie Jose Butel ◽  
Julio Aires

1980 ◽  
Vol 45 (1) ◽  
pp. 257-268
Author(s):  
C.W. Lloyd ◽  
S.B. Lowe ◽  
G.W. Peace

The growth regulator 2,4-D (2,4-dichlorophenoxyacetic acid) has been used to investigate the inter-relationship between cell elongation and cell division in carrot suspension cells. Maintained in 1 mg/l. 2,4-D, dividing populations of cells remain spheroidal and in clusters. But when subcultured into lower levels or zero, 2,4-D they increasingly elongate at the expense of division. Over the range of 0 to 1.0 mg/l, 2,4-D, elongation and division are therefore inversely related. However, by suppressing the mitogenic effect with FUdR it can be shown that cells do elongate in 1 mg/l. 2,4-D—a concentration which otherwise produces dividing, spheroidal cells. This indicates that mitogenc levels of 2,4-D do not perturb structures which support cellular elongation. This conclusion is confirmed by immuno- and electron-microscopy which show that development of elaborate arrays of cytoplasmic microtubules is unaffected by 1 mg/l. 2,4-D when FUdR is present. It is concluded that over the time periods under study here, 2,4-D regulates cell size (and shape) by stimulating growing cells to enter the division cycle and not by inhibiting elongation per se.


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