Effects of β-Mercaptoethylamine on Growth and Radiation Sensitivity of Escherichia coli Strain 15TAU-Bar

1966 ◽  
Vol 28 (3) ◽  
pp. 708 ◽  
Author(s):  
David M. Ginsberg
Keyword(s):  
Escherichia Coli ◽  
Radiation Sensitivity ◽  
Coli Strain

DIFFERENTIATION BETWEEN RADIATION-SENSITIVE AND -RESISTANT MUTANTS OF ESCHERICHIA COLI, STRAIN B

1965 ◽  
Vol 11 (2) ◽  
pp. 243-257 ◽  
Author(s):  
E. E. Woodside
Keyword(s):  
Escherichia Coli ◽  
Synthetic Medium ◽  
Dry Weight ◽  
Resistant Mutant ◽  
Viable Cell ◽  
Radiation Sensitivity ◽  
Coli Strain ◽  
Bacterial Populations ◽  
Morphological Heterogeneity ◽  
Radiation Resistant

Morphological heterogeneity in cell sizes of Escherichia coli, strains B, B/r, and BSprevents estimation of the viable cell count by the indirect turbidimetric method. The average dry weights of E. coli B, B/r, and BS, when grown in acetate synthetic medium, are 0.16, 0.10, and 0.13 picograms per cell respectively. Increased radiation sensitivity was correlated with those bacterial populations showing decreased intracellular glycogen content, decreased lipopolysaccharide–lipoprotein content, R-colony forms, and cellular elongation. The radiation-sensitive strains contained more DNA, RNA, and protein per cell than the radiation-resistant mutant; however, no significant differences were evident in the DNA, RNA, and protein contents on a dry weight basis. No qualitative differences in the monosaccharides or their derivatives were found. Intracellular glucose synthesis and accumulation preceded DNA, RNA, and protein synthesis throughout the lag and early logarithmic growth phases for all three strains. Multiple forms of intracellular glycogen complexes were present in all three strains. In addition to unbound glycogen and protein-bound glycogen, a bound form of glycogen was consistently associated with crude fractions which contained the DNA, RNA, and lipopolysaccharide constituents. Increased lability of the cold TCA-insoluble bound glycogen to hot TCA and alpha-amylase hydrolysis was correlated with increased radiosensitivities of the organisms.

scholarly journals Regulation of Expression of the TIR-Containing Protein C Gene of the Uropathogenic Escherichia coli Strain CFT073

Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 549
Author(s):  
Julia Ittensohn ◽  
Jacqueline Hemberger ◽  
Hannah Griffiths ◽  
Maren Keller ◽  
Simone Albrecht ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Protein C ◽  
Interleukin 1 ◽  
Coli Strain ◽  
Uropathogenic Escherichia Coli ◽  
Reporter Construct ◽  
Regulation Of Expression ◽  
E Coli ◽  
Strain Cft073 ◽  
Myeloid Differentiation Factor

The uropathogenic Escherichia coli strain CFT073 causes kidney abscesses in mice Toll/interleukin-1 receptor domain-containing protein C (TcpC) dependently and the corresponding gene is present in around 40% of E. coli isolates of pyelonephritis patients. It impairs the Toll-like receptor (TLR) signaling chain and the NACHT leucin-rich repeat PYD protein 3 inflammasome (NLRP3) by binding to TLR4 and myeloid differentiation factor 88 as well as to NLRP3 and caspase-1, respectively. Overexpression of the tcpC gene stopped replication of CFT073. Overexpression of several tcpC-truncation constructs revealed a transmembrane region, while its TIR domain induced filamentous bacteria. Based on these observations, we hypothesized that tcpC expression is presumably tightly controlled. We tested two putative promoters designated P1 and P2 located at 5′ of the gene c2397 and 5′ of the tcpC gene (c2398), respectively, which may form an operon. High pH and increasing glucose concentrations stimulated a P2 reporter construct that was considerably stronger than a P1 reporter construct, while increasing FeSO4 concentrations suppressed their activity. Human urine activated P2, demonstrating that tcpC might be induced in the urinary tract of infected patients. We conclude that P2, consisting of a 240 bp region 5′ of the tcpC gene, represents the major regulator of tcpC expression.

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