Increased retention of functional fusions to toxic genes in new two-hybrid libraries of the E. coli strain MG1655 and B. subtilis strain 168 genomes, prepared without passaging through E. coli

Abstract Three strains of Escherichia coli(ATCC 128,10536, and 25922) and one strain of Bacillus subtilis (ATCC 3491) were compared as indicator microorganisms in microbial inhibition tests for their ability to detect fluoroquinolone residues. E. coli strains 128 and 10536 were most susceptible to fluoroquinolone residues, with detection limits of 35-50 μg/kg for enrofloxacin. Of the 2 strains, E. coli 10536 was slightly less susceptible. Ciprofloxacin was detected consistently by E. coli 128 at 30 μg/kg. Other fluoroquinolone drugs of veterinary interest detected by E. coli 128 were sarafloxacin and difloxacin at 100-250 μg/kg concentration. E. coli25922 yielded 100% sensitivity in detection of enrofloxacin only at the 250 μg/kg concentration, and ciprofloxacin and sarafloxacin at 200 μg/kg. B. subtilis detected only enrofloxacin 100% of the time at 250 μg/kg. The E. coli strains tested were insensitive to other antibacterials commonly used in animals, with the exception of ceftiofur which was detected by E. coli 128 and 10536 at 500 μg/kg. The B. subtilis strain was not effective in detecting the fluoroquinolone drugs, whereas the E. coli strains were selective for the fluoroquinolones. E. coli 128 was 100% effective in detecting enrofloxacin and ciprofloxacin in spiked diaphragm homogenate samples at 50 μg/kg. Of the microorganisms tested, E. coli strain ATCC 128 was highly suitable as an indicator microorganism in a microbial inhibition assay for selective detection of fluoroquinolone antibacterial residues in animal tissues.

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A subtractive hybridisation analysis of genomic differences between the uropathogenic E. coli strain 536 and the E. coli K-12 strain MG1655

FEMS Microbiology Letters ◽

10.1111/j.1574-6968.2001.tb10651.x ◽

2001 ◽

Vol 199 (1) ◽

pp. 61-66 ◽

Cited By ~ 32

Author(s):

Britta Janke ◽

Ulrich Dobrindt ◽

JÃ¶rg Hacker ◽

Gabriele Blum-Oehler

Keyword(s):

Coli Strain ◽

Strain Mg1655 ◽

E Coli ◽

Subtractive Hybridisation ◽

Hybridisation Analysis ◽

K 12

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Deadly E. Coli Strain May Evade EPA's Test

Chemical & Engineering News ◽

10.1021/cen020811151303 ◽

2011 ◽

pp. 020811151303

Author(s):

Sara Peach

Keyword(s):

Coli Strain ◽

E Coli

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Transport of escherichia coli through soil to groundwater traced by randomly amplified polymorphic DNA (RAPD)

Water Science & Technology ◽

10.2166/wst.1997.0758 ◽

1997 ◽

Vol 35 (11-12) ◽

pp. 351-357 ◽

Cited By ~ 2

Author(s):

R. Rothmaier ◽

A. Weidenmann ◽

K. Botzenhart

Keyword(s):

Negative Impact ◽

Random Amplified Polymorphic Dna ◽

Coli Strain ◽

Soil Samples ◽

Test Field ◽

Liquid Manure ◽

E Coli ◽

Rapd Pattern ◽

Geological Situation ◽

Different Strains

Isolates (50) of E. coli obtained from liquid manure (20 bovine, 20 porcine) were genotyped using random amplified polymorphic DNA (RAPD). Typing revealed 9 and 14 different strains in bovine and porcine liquid manure respectively with no strains in common. One porcine strain, showing a simple RAPD pattern, was subcultured and spread on a test field (1.5l/m2 at 1010 cfu/l) in a drinking water protection zone with loamy to sandy sediments in the Donauried area, Baden-Wurttemberg. Soil samples and groundwaters were collected at monthly intervals October 1994 – June 1995 during which 114 E. coli isolates were recovered. The first occurrence and maximum concentration of E. coli in soil samples taken from more than 20cm depth was in January 1995, declining rapidly with depth and time. All isolates from soil and only one from groundwater showed the RAPD pattern of the spread E. coli strain. The results could not demonstrate a severe negative impact of the spreading of liquid manure on the bacteriological quality of the groundwater in the given geological situation. The distinct strain patterns found in different kinds of liquid manure suggest that genotyping of E. coli by RAPD may be an adequate tool for tracing sources of faecal contamination.

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Low endotoxin E. coli strain-derived plasmids reduced rAAV vector-mediated immune responses both in vitro and in vivo.

Molecular Therapy — Methods & Clinical Development ◽

10.1016/j.omtm.2021.06.009 ◽

2021 ◽

Author(s):

Qingyun Zheng ◽

Tianyi Wang ◽

Xiangying Zhu ◽

Xiao Tian ◽

Chen Zhong ◽

...

Keyword(s):

Immune Responses ◽

Coli Strain ◽

Raav Vector ◽

E Coli

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A Unique Approach for Quantitative Risk Assessment for Cryptosporidiosis and E. coli Strain O157 from Cattle Feces

Proceedings of the Water Environment Federation ◽

10.2175/193864700784994731 ◽

2000 ◽

Vol 2000 (16) ◽

pp. 615-645

Author(s):

John L. Cicmanec

Keyword(s):

Risk Assessment ◽

Coli Strain ◽

Quantitative Risk Assessment ◽

E Coli ◽

Cattle Feces ◽

Unique Approach

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

Pathogens ◽

10.3390/pathogens10050549 ◽

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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Novel Bacterial Production of Two Different Bioactive Forms of Human Stem-Cell Factor

International Journal of Molecular Sciences ◽

10.3390/ijms22126361 ◽

2021 ◽

Vol 22 (12) ◽

pp. 6361

Author(s):

Eunyoung Lee ◽

Michelle Novais de Paula ◽

Sangki Baek ◽

Huynh Kim Khanh Ta ◽

Minh Tan Nguyen ◽

...

Keyword(s):

Stem Cell ◽

Ion Exchange ◽

Stem Cell Factor ◽

Transmembrane Domain ◽

Coli Strain ◽

Exchange Chromatography ◽

Soluble Form ◽

Human Stem Cell ◽

E Coli ◽

Human Stem Cell Factor

Human stem-cell factor (hSCF) stimulates the survival, proliferation, and differentiation of hematopoietic cells by binding to the c-Kit receptor. Various applications of hSCF require the efficient and reliable production of hSCF. hSCF exists in three forms: as two membrane-spanning proteins hSCF248 and hSCF229 and truncated soluble N-terminal protein hSCF164. hSCF164 is known to be insoluble when expressed in Escherichia coli cytoplasm, requiring a complex refolding procedure. The activity of hSCF248 has never been studied. Here, we investigated novel production methods for recombinant hSCF164 and hSCF248 without the refolding process. To increase the solubility of hSCF164, maltose-binding protein (MBP) and protein disulfide isomerase b’a’ domain (PDIb’a’) tags were attached to the N-terminus of hSCF164. These fusion proteins were overexpressed in soluble form in the Origami 2(DE3) E. coli strain. These solubilization effects were enhanced at a low temperature. His-hSCF248, the poly-His tagged form of hSCF248, was expressed in a highly soluble form without a solubilization tag protein, which was unexpected because His-hSCF248 contains a transmembrane domain. hSCF164 was purified using affinity and ion-exchange chromatography, and His-hSCF248 was purified by ion-exchange and gel filtration chromatography. The purified proteins stimulated the proliferation of TF-1 cells. Interestingly, the EC50 value of His-hSCF248 was 1 pg/mL, 100-fold lower than 9 ng/mL hSCF164. Additionally, His-hSCF248 decreased the doubling time, increased the proportion of S and G2/M stages in the cell cycle, and increased the c-Myc expression at a 1000-fold lower concentration than hSCF164. In conclusion, His-hSCF248 was expressed in a soluble form in E. coli and had stronger activity than hSCF164. The molecular chaperone, MBP, enabled the soluble overexpression of hSCF164.

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