Norepinephrine augmented in vitro growth of uropathogenic E. coli in Type 2 diabetes mellitus and its suppression by silodosin (alpha blocker)

Effects of Catecholamine Stress Hormones Norepinephrine and Epinephrine on Growth, Antimicrobial Susceptibility, Biofilm Formation, and Gene Expressions of Enterotoxigenic Escherichia coli

Enterotoxigenic Escherichia coli (ETEC) is a significant contributor to diarrhea. To determine whether ETEC-catecholamine hormone interactions contribute to the development of diarrhea, we tested the effects of catecholamine hormones acting on ETEC in vitro. The results showed that in the presence of norepinephrine (NE) and epinephrine (Epi), the growth of 9 out of 10 ETEC isolates was promoted, the MICs of more than 60% of the isolates to 6 antibiotics significantly increased, and the biofilm formation ability of 10 ETEC isolates was also promoted. In addition, NE and Epi also significantly upregulated the expression of the virulence genes feaG, estA, estB, and elt. Transcriptome analysis revealed that the expression of 290 genes was affected by NE. These data demonstrated that catecholamine hormones may augment the diarrhea caused by ETEC.

Effect of pH, Norepinephrine and Glucose on Metabolic and Biofilm Activity of Uropathogenic Microorganisms

Urinary tract infection (UTIs) aremainly caused by a number of anatomical and physiological dysfunctions, but there are also some iatrogenic factors, including the use of certain medications, that contribute to the development of UTIs. The virulence of bacteria that colonize the urinary tract may be modified by pH and by the presence of soluble substances in urine, such as norepinephrine (NE) and glucose. In this work, we studied the influence of NE and glucose across a range of pHs (5, 7, 8) on the biomass, matrix production and metabolism of uropathogenic strains of Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus and Enterococcus faecalis. We used Congo red and gentian violet to stain the extracellular matrix and biomass, respectively, of biofilms. The optical density of staining of the biofilms was measured using a multichannel spectrophotometer. The metabolic activity was analyzed by MTT assay. It was shown that NE and glucose stimulate biomass production both in the Gram-negative and Gram-positive uropathogens. The metabolic activity in the presence of glucose was higher at pH 5 for E. coli (in 4.0 ± 0.1 times), Ps. aeruginosa (in 8.2 ± 0.2 times) and Kl. pneumoniae (in 4.1 ± 0.2 times). Matrix production of Kl. pneumoniae increased under NE (in 8.2 ± 0.2 times) and in the presence of glucose (in 1.5 ± 0.3 times). Thus, NE and glucose in urine may lead to persistent UTI under patient stress and in the case of metabolic glucose disorders.

Adaptive strategies of uropathogenic Escherichia coli CFT073: from growth in lab media to virulence during host cell adhesion

Urinary tract infections (UTIs) are a major concern in public health. The prevalent uropathogenic bacterium in healthcare settings is Escherichia coli. The increasing rate of antibiotic-resistant strains demands studies to understand E. coli pathogenesis to drive the development of new therapeutic approaches. This study compared the gene expression profile of selected target genes in the prototype uropathogenic E. coli (UPEC) strain CFT073 grown in Luria Bertani (LB), artificial urine (AU), and during adhesion to host bladder cells by semi-quantitative real-time PCR (RT-PCR) assays. AU effectively supported the growth of strain CFT073 as well as other E. coli strains with different lifestyles, thereby confirming the appropriateness of this medium for in vitro models. Unexpectedly, gene expression of strain CFT073 in LB and AU was quite similar; conversely, during the adhesion assay, adhesins and porins were upregulated, while key global regulators were downregulated with respect to lab media. Interestingly, fimH and papGII genes were significantly expressed in all tested conditions. Taken together, these results provide for the first time insights of the metabolic and pathogenic profile of strain CFT073 during the essential phase of host cell adhesion.