scholarly journals Pharmacodynamic activity of ertapenem versus genotypically characterized extended-spectrum  -lactamase (ESBL)-, KPC- or NDM-producing Escherichia coli with reduced susceptibility or resistance to ertapenem using an in vitro model

2014 ◽  
Vol 69 (9) ◽  
pp. 2448-2452 ◽  
Author(s):  
G. G. Zhanel ◽  
A. Denisuik ◽  
S. Vashisht ◽  
C. Yachison ◽  
H. J. Adam ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
In Vitro Model ◽  
Extended Spectrum ◽  
Vitro Model

scholarly journals An in vitro model of catheter-associated urinary tract infections to investigate the role of uncommon bacteria on the Escherichia coli microbial consortium

2017 ◽  
Vol 118 ◽  
pp. 64-69 ◽  
Author(s):  
Andreia S. Azevedo ◽  
Carina Almeida ◽  
Luciana C. Gomes ◽  
Carla Ferreira ◽  
Filipe J. Mergulhão ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
In Vitro Model ◽  
Microbial Consortium ◽  
Vitro Model ◽  
Tract Infections

scholarly journals Predictors of effect of ampicillin-sulbactam against TEM-1 beta-lactamase-producing Escherichia coli in an in vitro dynamic model: enzyme activity versus MIC.

1996 ◽  
Vol 40 (3) ◽  
pp. 734-738 ◽  
Author(s):  
A A Firsov ◽  
D Saverino ◽  
D Savarino ◽  
M Ruble ◽  
D Gilbert ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
In Vitro Model ◽  
Dynamic Models ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Time Curve ◽  
Peripheral Tissues ◽  
Vitro Model

The clinical outcome in patients treated with ampicillin-sulbactam may not always be predictable by disc susceptibility testing or with the MIC as determined with a constant level (4 micrograms/ml) of the beta-lactamase inhibitor (MIC1). The enzyme activities (EA) and the MICs estimated at a constant ratio of ampicillin to sulbactam of 2:1 (MIC2) for 15 TEM-1 beta-lactamase-producing strains of Escherichia coli were examined as alternatives to MIC1 as predictors of the antibacterial effects of this combined drug as studied in an in vitro model which simulates ampicillin-sulbactam pharmacokinetic profiles observed in human peripheral tissues. Integral parameters describing the area under the bacterial count-time curve (AUBC), the area between the normal growth curve, and the killing curve of bacteria exposed to antibiotic (ABBC), and the second parameter expressed as a percentage of its maximal hypothetical value (ABBC/ABBCmax) were calculated. All three parameters correlated well with EA (AUBC, r = 0.93; ABBC, r = -0.88; ABBC/ABBCmax, r = -0.91) and with MIC2 (r = 0.94, -0.94, and -0.95, respectively) but not with MIC1. Both EA and MIC2 can be considered reliable predictors of the antibacterial effect of ampicillin-sulbactam in an in vitro model. These correlations suggest that in vitro kinetic-dynamic models might be useful to reexamine established susceptibility breakpoints obtained with data based on the MIC1 (MICs obtained with constant levels of beta-lactamase inhibitors). These data also suggest that quantitative determinations of bacterial beta-lactamase production and MICs based on the component concentration ratio observed in vivo might be useful predictors of the effect of ampicillin-sulbactam and other beta-lactam-inhibitor combinations.

scholarly journals ISEcp1-Mediated Transposition of qnrB-Like Gene in Escherichia coli

2008 ◽  
Vol 52 (8) ◽  
pp. 2929-2932 ◽  
Author(s):  
Vincent Cattoir ◽  
Patrice Nordmann ◽  
Jesus Silva-Sanchez ◽  
Paula Espinal ◽  
Laurent Poirel
Keyword(s):  
Escherichia Coli ◽  
Clinical Isolate ◽  
In Vitro Model ◽  
Resistance Determinant ◽  
Insertion Element ◽  
Its Gene ◽  
Vitro Model

ABSTRACT A novel QnrB-like plasmid-mediated resistance determinant, QnrB19, was identified from an Escherichia coli clinical isolate from Colombia. Its gene was associated with an ISEcp1-like insertion element that did not act as a promoter for its expression. Using an in vitro model of transposition, we showed that the ISEcp1-like element was able to mobilize the qnrB19 gene.

scholarly journals Temporal Expression of Enteropathogenic Escherichia coli Virulence Genes in an In Vitro Model of Infection

2005 ◽  
Vol 73 (2) ◽  
pp. 1034-1043 ◽  
Author(s):  
Laura Q. Leverton ◽  
James B. Kaper
Keyword(s):  
Escherichia Coli ◽  
In Vitro Model ◽  
Virulence Genes ◽  
Host Cells ◽  
Temporal Expression ◽  
Lesion Formation ◽  
Culture Models ◽  
Vitro Model ◽  
Enterocyte Effacement

ABSTRACT The hallmark of enteropathogenic Escherichia coli (EPEC) infection is the ability of EPEC to cause attaching and effacing (A/E) lesions on intestinal epithelium. This event is reproducible in in vitro tissue culture models of infection. We used real-time PCR to measure transcription from several locus of enterocyte effacement (LEE) operons (LEE1 to LEE5) and from bfp during a 5-h infection of HEp-2 cells with EPEC. We found that after the initial formation of A/E lesions, which occurs as early as 5 min postinfection, EPEC continues to increase transcription from LEE3 to LEE5 as well as from bfp. These levels are maximized by 3 h postinfection and remain constant throughout the course of infection. This increase in transcription from LEE3 to LEE5 occurs when LEE1 (ler) transcription is decreasing. EspA, EspB, intimin, Tir, and bundle-forming pilus expression is detectable during the entire 5-h infection. These results indicate that the EPEC genes involved in localized and intimate adherence are continually expressed after the initial stages of A/E lesion formation on host cells.

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