scholarly journals Glycosuria alters uropathogenic Escherichia coli global gene expression and virulence

2021 ◽  
Author(s):  
Ritwij Kulkarni ◽  
Md. Jahirul Islam ◽  
Kamal Bagale ◽  
Preeti P John ◽  
Zachary Kurtz
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Epidemiological Data ◽  
Global Gene Expression ◽  
Metabolic Genes ◽  
Central Hypothesis ◽  
Surrogate Measure ◽  
Tract Infections

Uropathogenic Escherichia coli (UPEC) is the principal etiology of more than half of urinary tract infections (UTI) in humans with diabetes mellitus. Epidemiological data and studies in mouse model of ascending UTI have elucidated various host factors responsible for increasing the susceptibility of diabetic hosts to UPEC-UTI. In contrast, the nature of alterations in UPEC physiology mediated by diabetic urinary microenvironment and the contributions of altered UPEC physiology in shaping UPEC-UTI pathogenesis in diabetes have not been examined. Our central hypothesis is that glycosuria directly induces urinary virulence of UPEC. We compared virulence characteristics and gene expression in human UPEC strains UTI89 (cystitis) and CFT073 (pyelonephritis) exposed for 2h, in vitro to human urine either in the presence or absence of glycosuria (600mg/dl glucose). Compared to control UPEC exposed to nutrient-rich culture medium LB, glycosuria-exposed UPEC exhibited significant increase in biofilm formation and reduction in the hemagglutination of Guinea pig erythrocytes (a surrogate measure of type 1 piliation). In addition, analysis of UTI89 transcriptome by RNA sequencing revealed that 2h-long, in vitro exposure to glycosuria also significantly alters expression of virulence and metabolic genes central to urinary virulence of UPEC. In summary, our results provide novel insights into how glycosuria-mediated early changes in UPEC fitness may facilitate UTI pathogenesis in the diabetic urinary microenvironment.

scholarly journals Global Gene Expression Profiling of the Asymptomatic Bacteriuria Escherichia coli Strain 83972 in the Human Urinary Tract

2006 ◽  
Vol 74 (6) ◽  
pp. 3565-3575 ◽  
Author(s):  
Viktoria Roos ◽  
Per Klemm
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Urinary Tract ◽  
Expression Profiles ◽  
Asymptomatic Bacteriuria ◽  
Global Gene Expression ◽  
E Coli ◽  
Tract Infections

ABSTRACT Urinary tract infections (UTIs) are an important health problem worldwide, with many million cases each year. Escherichia coli is the most common organism causing UTIs in humans. The asymptomatic bacteriuria E. coli strain 83972 is an excellent colonizer of the human urinary tract, where it causes long-term bladder colonization. The strain has been used for prophylactic purposes in patients prone to more severe and recurrent UTIs. For this study, we used DNA microarrays to monitor the expression profile of strain 83972 in the human urinary tract. Significant differences in expression levels were seen between the in vivo expression profiles of strain 83972 in three patients and the corresponding in vitro expression profiles in lab medium and human urine. The data revealed an in vivo lifestyle of microaerobic growth with respiration of nitrate coupled to degradation of sugar acids and amino acids, with no signs of attachment to host tissues. Interestingly, genes involved in NO protection and metabolism showed significant up-regulation in the patients. This is one of the first studies to address bacterial whole-genome expression in humans and the first study to investigate global gene expression of an E. coli strain in the human urinary tract.

In Vitro Adhesion of Uropathogenic Escherichia coli to Human Periurethral Cells

1980 ◽  
Vol 28 (3) ◽  
pp. 972-980 ◽  
Author(s):  
Gunilla Källenius ◽  
Roland Möllby ◽  
Jan Winberg
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Human Erythrocytes ◽  
System A ◽  
Urethral Orifice ◽  
History Of ◽  
In Vitro Adhesion ◽  
Tract Infections

The in vitro adhesion of three uropathogenic strains of Escherichia coli to epithelial cells from the periurethral area (area surrounding the urethral orifice) of women with and without a history of recurrent urinary tract infections was investigated. All strains showed a specific mannose-resistant hemagglutination restricted to human erythrocytes. Since only a few hundred periurethral cells were used in each test, gentle methods were required. Optimal results were obtained with bacteria grown for 16 h at 37°C in nutrient broth without shaking. The binding of bacteria seemed to be irreversible under the conditions studied, since repeated washings of the epithelial cells after incubation did not decrease the number of adhering bacteria. Chloramphenicol was used to control the number of added bacteria in the incubation system. A difference in the adhesive capacity of periurethral cells of infection-prone and healthy individuals was most evident at concentrations of 2.5 × 10 9 bacteria/ml. Electron microscope studies indicated that pili mediated the adhesion. Adhesion was correlated with the mannose-resistant hemagglutination of human erythrocytes, indicating that the pili were not type 1 pili. Day-to-day variations in the adhesiveness of the bacteria were reduced by selecting well-adhering bacteria with the aid of in vitro passage on periurethral cells or human erythrocytes, and by exclusion of bacteria with low hemagglutination ability.

scholarly journals In Vivo Phase Variation of Escherichia coli Type 1 Fimbrial Genes in Women with Urinary Tract Infection

1998 ◽  
Vol 66 (7) ◽  
pp. 3303-3310 ◽  
Author(s):  
Jean K. Lim ◽  
Nereus W. Gunther ◽  
Hui Zhao ◽  
David E. Johnson ◽  
Susan K. Keay ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Acute Pyelonephritis ◽  
Urine Samples ◽  
E Coli ◽  
Type 1 Fimbriae ◽  
Tract Infections

ABSTRACT Type 1 fimbriae, expressed by most Escherichia colistrains, are thought to attach to human uroepithelium as an initial step in the pathogenesis of urinary tract infections (UTI). Numerous reports using both in vitro and murine models support this role for type 1 fimbriae in colonization. Unfortunately, only a limited number of studies have directly examined the expression of fimbriae in vivo. To determine whether type 1 fimbrial genes are transcribed during an acute UTI, we employed a modification of an established method. The orientation (ON or OFF) of the invertible promoter element, which drives transcription of type 1 fimbrial genes, was determined by PCR amplification using primers that flank the invertible element, followed by SnaBI digestion. The orientation of the type 1 fimbrial switch was determined under three experimental conditions. First,E. coli strains from different clinical sources (acute pyelonephritis patients, cystitis patients, and fecal controls) were tested under different in vitro culture conditions (agar versus broth; aerated versus static). The genes in the more-virulent strains (those causing acute pyelonephritis) demonstrated a resistance, in aerated broth, to switching from OFF to ON, while those in fecal strains readily switched from OFF to ON. Second, bladder and kidney tissue from CBA mice transurethrally inoculated with E. coli CFT073 (an established murine model of ascending UTI) was assayed. The switches directly amplified from infected bladder and kidney tissues were estimated to be 33 and 39% ON, respectively, by using a standard curve. Finally, bacteria present in urine samples collected from women with cystitis were tested for type 1 fimbria switch orientation. For all 11 cases, an average of only 4% of the switches in the bacteria in the urine were ON. In 7 of the 11 cases, we found that all of the visible type 1 fimbrial switches were in the OFF position (upper limit of detection of assay, 98% OFF). Strains recovered from these urine samples, however, were shown after culture in vitro to be capable of switching the fimbrial gene to the ON position and expressing mannose-sensitive hemagglutinin. The results from experimental infections and cases of cystitis in women suggest that type 1 fimbrial genes are transcribed both in the bladder and in the kidney. However, those bacteria found in the urine and not attached to the uroepithelium are not transcriptionally active for type 1 fimbrial genes.

scholarly journals The Gene Expression Profile of Uropathogenic Escherichia coli in Women with Uncomplicated Urinary Tract Infections Is Recapitulated in the Mouse Model

mBio ◽  
2020 ◽  
Vol 11 (4) ◽  
Author(s):  
Arwen E. Frick-Cheng ◽  
Anna Sintsova ◽  
Sara N. Smith ◽  
Michael Krauthammer ◽  
Kathryn A. Eaton ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Urinary Tract ◽  
Mouse Model ◽  
Experimental Models ◽  
Human Infection ◽  
Bacterial Physiology ◽  
Continued Use ◽  
Tract Infections

ABSTRACT Uropathogenic Escherichia coli (UPEC) is the primary causative agent of uncomplicated urinary tract infections (UTIs). UPEC fitness and virulence determinants have been evaluated in a variety of laboratory settings, including a well-established mouse model of UTI. However, the extent to which bacterial physiologies differ between experimental models and human infections remains largely understudied. To address this important issue, we compared the transcriptomes of three different UPEC isolates in human infection and under a variety of laboratory conditions, including LB culture, filter-sterilized urine culture, and the UTI mouse model. We observed high correlation in gene expression between the mouse model and human infection in all three strains examined (Pearson correlation coefficients of 0.86 to 0.87). Only 175 of 3,266 (5.4%) genes shared by all three strains had significantly different expression levels, with the majority of them (145 genes) downregulated in patients. Importantly, gene expression levels of both canonical virulence factors and metabolic machinery were highly similar between the mouse model and human infection, while the in vitro conditions displayed more substantial differences. Interestingly, comparison of gene expression between the mouse model and human infection hinted at differences in bladder oxygenation as well as nutrient composition. In summary, our work strongly validates the continued use of this mouse model for the study of the pathogenesis of human UTI. IMPORTANCE Different experimental models have been used to study UPEC pathogenesis, including in vitro cultures in different media, tissue culture, and mouse models of infection. The last is especially important since it allows evaluation of mechanisms of pathogenesis and potential therapeutic strategies against UPEC. Bacterial physiology is greatly shaped by environment, and it is therefore critical to understand how closely bacterial physiology in any experimental model relates to human infection. In this study, we found strong correlation in bacterial gene expression between the mouse model and human UTI using identical strains, suggesting that the mouse model accurately mimics human infection, definitively supporting its continued use in UTI research.

scholarly journals The Gene Expression Profile of Uropathogenic Escherichia coli in Women with Uncomplicated Urinary Tract Infections Is Recapitulated in the Mouse Model

2020 ◽  
Author(s):  
Arwen E. Frick-Cheng ◽  
Anna Sintsova ◽  
Sara N. Smith ◽  
Michael Krauthammer ◽  
Kathryn A. Eaton ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Urinary Tract ◽  
Mouse Model ◽  
Experimental Models ◽  
Human Infection ◽  
Bacterial Physiology ◽  
Continued Use ◽  
Tract Infections

AbstractUropathogenic Escherichia coli (UPEC) is the primary causative agent of uncomplicated urinary tract infections (UTIs). UPEC fitness and virulence determinants have been evaluated in a variety of laboratory settings that include a well-established mouse model of UTI. However, the extent to which bacterial physiology differs between experimental models and human infections remains largely understudied. To address this important question, we compared the transcriptomes of three different UPEC isolates in human infection and a variety of laboratory conditions including LB culture, filter-sterilized urine culture, and the UTI mouse model. We observed high correlation in gene expression between the mouse model and human infection in all three strains examined (Pearson correlation coefficient of 0.86-0.87). Only 175 of 3,266 (5.4%) genes shared by all three strains had significantly different expression levels, with the majority of them (145 genes) down-regulated in patients. Importantly, gene expression of both canonical virulence factors and metabolic machinery were highly similar between the mouse model and human infection, while the in vitro conditions displayed more substantial differences. Interestingly, comparison of gene expression between the mouse model and human infection hint at differences in bladder oxygenation as well as nutrient composition. In summary, our work strongly validates the continued use of this mouse model for the study of the pathogenesis of human UTI.ImportanceDifferent experimental models have been used to study UPEC pathogenesis including in vitro cultures in different media, tissue culture, as well as mouse models of infection. The latter is especially important since it allows evaluation of mechanisms of pathogenesis and potential therapeutic strategies against UPEC. Bacterial physiology is greatly shaped by environment and it is therefore critical to understand how closely bacterial physiology in any experimental model relates to human infection. In this study, we found a very strong correlation in bacterial gene expression between the mouse model and human UTI using identical strains, suggesting that the mouse model accurately mimics human infection, definitively supporting its continued use in UTI research.

scholarly journals Biological Cost of Single and Multiple Norfloxacin Resistance Mutations in Escherichia coli Implicated in Urinary Tract Infections

2005 ◽  
Vol 49 (6) ◽  
pp. 2343-2351 ◽  
Author(s):  
Patricia Komp Lindgren ◽  
Linda L. Marcusson ◽  
Dorthe Sandvang ◽  
Niels Frimodt-Møller ◽  
Diarmaid Hughes
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Infection Model ◽  
Resistance Mutations ◽  
Topoisomerase Iv ◽  
E Coli ◽  
Tract Infections ◽  
Subsequent Selection

ABSTRACT Resistance to fluoroquinolones in urinary tract infection (UTIs) caused by Escherichia coli is associated with multiple mutations, typically those that alter DNA gyrase and DNA topoisomerase IV and those that regulate AcrAB-TolC-mediated efflux. We asked whether a fitness cost is associated with the accumulation of these multiple mutations. Mutants of the susceptible E. coli UTI isolate Nu14 were selected through three to five successive steps with norfloxacin. Each selection was performed with the MIC of the selected strain. After each selection the MIC was measured; and the regions of gyrA, gyrB, parC, and parE, previously associated with resistance mutations, and all of marOR and acrR were sequenced. The first selection step yielded mutations in gyrA, gyrB, and marOR. Subsequent selection steps yielded mutations in gyrA, parE, and marOR but not in gyrB, parC, or acrR. Resistance-associated mutations were identified in almost all isolates after selection steps 1 and 2 but in less than 50% of isolates after subsequent selection steps. Selected strains were competed in vitro, in urine, and in a mouse UTI infection model against the starting strain, Nu14. First-step mutations were not associated with significant fitness costs. However, the accumulation of three or more resistance-associated mutations was usually associated with a large reduction in biological fitness, both in vitro and in vivo. Interestingly, in some lineages a partial restoration of fitness was associated with the accumulation of additional mutations in late selection steps. We suggest that the relative biological costs of multiple mutations may influence the evolution of E. coli strains that develop resistance to fluoroquinolones.

Long-Term Treatment with Pivmecillinam in Patients with Recurrent Bacteriuria

1982 ◽  
Vol 10 (3) ◽  
pp. 179-182
Author(s):  
B Bresky ◽  
K Lincoln
Keyword(s):  
Escherichia Coli ◽  
Adverse Effect ◽  
Renal Function ◽  
Term Treatment ◽  
The Body ◽  
End Of Treatment ◽  
Long Term Treatment ◽  
Tract Infections

Thirty out-patients with chronic recurrent urinary tract infections, who had failed to respond to 10 days treatment with either pivmecillinam and/or amoxycillin, received a 3-month course of pivmecillinam at a dose of 200 mg, three times daily. Twenty-seven patients had bacteriuria due to Enterobacteriaceae, mainly Escherichia coli, sensitive to mecillinam in vitro. Pivmecillinam eradicated all the initial urinary pathogens. Reinfections occurred during treatment in three patients, who remained asymptomatic. Four subjects complained of gastro-intestinal side-effects, and therapy was withdrawn in three instances. Another three patients described unusual adverse events towards the end of the course of treatment, described as an odd sensation in the body and a desire for salt. The sensation disappeared a few days after the end of treatment. Treatment with pivmecillinam had no adverse effect on haematopoietic, hepatic or renal function.

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