Metabolic Adaptations of Uropathogenic E. coli in the Urinary Tract

Mann, Riti; Mediati, Daniel G.; Duggin, Iain G.; Harry, Elizabeth J.; Bottomley, Amy L.

doi:10.3389/fcimb.2017.00241

Cited by 98 publications

(101 citation statements)

References 110 publications

(201 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Urine contains relatively high concentrations of urea, creatinine, amino acids, organic acids, inorganic ions (eg, ammonia, sodium, potassium), purines, and pyrimidines, which could affect E. coli growth . Increasing osmolality with sodium chloride or ammonium were not found to increase antibacterial activity .…”

Section: Discussionmentioning

confidence: 96%

The Effect of Urine Concentration and pH on the Growth of Escherichia Coli in Canine Urine In Vitro

Thornton

Burchell

Burton

et al. 2018

Veterinary Internal Medicne

View full text Add to dashboard Cite

BackgroundLower urinary tract infections are common in dogs, and Escherichia coli is the most common bacterial pathogen isolated. The literature has conflicting evidence regarding the inhibitory effects of urine concentration and pH on E. coli growth.Hypothesis/ObjectivesTo determine the effect of different pH and urine concentrations on E. coli growth in vitro.AnimalsVoided urine samples from 10 apparently healthy spayed female dogs were used.MethodsA matrix of 9 urine specific gravity (USG; 1.010, 1.020, and 1.030) and pH (5.5, 7.0, and 8.5) combinations was prepared by diluting and titrating filtered voided urine samples. Three E. coli isolates were obtained from urine of female dogs with signs of lower urinary tract infection and cultured at different urine pH and USG combinations in wells of a microtiter plate. The number of E. coli colony‐forming units (CFU) per mL of urine was calculated after aerobic incubation of the urine at 37°C for 18 hours, and statistically compared.ResultsSignificant differences were identified in the mean log CFU/mL among different combinations of pH and USG. The lowest log CFU/mL were observed in alkaline concentrated urine (pH 8.5 and USG 1.030).Conclusions and Clinical Importance Escherichia coli in vitro growth was higher in neutral to acidic and diluted urine compared to alkaline and concentrated urine. The impact of non‐alkalizing diluting diets on the incidence of E. coli lower urinary tract infections should be further explored.

show abstract

Section: Discussionmentioning

confidence: 96%

The Effect of Urine Concentration and pH on the Growth of Escherichia Coli in Canine Urine In Vitro

Thornton

Burchell

Burton

et al. 2018

Veterinary Internal Medicne

View full text Add to dashboard Cite

show abstract

“…Extensive research provides increasingly strong evidence of the importance of uropathogenic Escherichia coli (UPEC) strains for medical and epidemiological problems. Their remarkable adaptive abilities are conductive to acute or chronic urinary tract infections (UTI) and cause serious therapeutic problems [1,2]. Nowadays they are not only seen as E. coli isolated from urine, but a specialized pathotype with specific mechanisms of intracellular pathogenicity, which allow for colonization of the urinary tract, avoidance of host defenses and causing damage to the uroepithelium [3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Ciprofloxacin, amoxicillin, and aminoglycosides stimulate genetic and phenotypic changes in uropathogenic Escherichia coli strains

et al. 2019

View full text Add to dashboard Cite

Antibiotic therapy and its consequences in bacterial and human aspects are widely investigated. Despite this, the emergence of new multidrug resistant bacteria is still a current problem. The scope of our work included the observation of changes among uropathogenic Escherichia coli strains after the treatment with a subinhibitory concentration of different antibiotics. The sensitive strains with or without virulence factors were incubated with amoxicillin, ciprofloxacin, gentamycin, or tobramycin. After each passage, the E. coli derivatives were compared to their wild types based on their susceptibility profiles, virulence genes, biofilm formations and the fingerprint profiles of PCR products amplified with using the (N)(6)(CGG)(4) primer. It turned out that antibiotics caused significant changes in the repertoire of bacterial virulence and biofilm formation, corresponding to acquired cross-resistance. The genomic changes among the studied bacteria were reflected in the changed profiles of the CGG-PCR products. In conclusion, the inappropriate application of antibiotics may cause a rapid rise of Multidrug Resistant (MDR) strains and give bacteria a chance to modulate their own pathogenicity. This phenomenon has been easily observed among uropathogenic E. coli strains and it is one of the main reasons for recurrent infections of the urinary tract.

show abstract

“…Our results support these findings, as low pH values were associated with a significant decrease in fosfomycin MIC values for resistant strains into the susceptible range (Table 1). Other factors than acidic pH may alter the growth of E. coli in urine, such as the lack of essential sources of metabolic elements like urea, creatinine, iron, citric acid, D-serine, or ammonia (21).…”

Section: Discussionmentioning

confidence: 99%

Unexpected activity of oral fosfomycin against resistant strains ofEscherichia coliin murine pyelonephritis

Pourbaix

Guérin

Burdet

et al. 2019

Preprint

View full text Add to dashboard Cite

26Fosfomycin-tromethamine activity is well established for oral treatment of uncomplicated 27 lower urinary tract infections but little is known about its potential efficacy in 28 pyelonephritis. Ascending pyelonephritis was induced in mice infected with 6 strains of 29 Escherichia coli (fosfomycin MICs: 1 µg/ml to 256 µg/ml). Urine pH was 4.5 before 30 infection and 5.5-6.0 during infection. Animals were treated for 24h with fosfomycin (100 31 mg/kg subcutaneously every 4 hours) and CFU were enumerated in kidneys 24h after the 32 last fosfomycin injection. Peak (20.5 µg/ml at 1h) and trough (3.5 µg/ml at 4h) levels in 33 plasma were comparable to those obtained in human after an oral dose of 3 grams. 34 Fosfomycin treatment significantly reduced bacterial loads in kidneys (3.65 log 10 CFU/g 35 [min-max=1.83-7.03] and 1.88 log 10 CFU/g [1.78-5.74] in start-of-treatment control mice 36 and treated mice, respectively, P < 10 -6 ). However, this effect was not found to differ 37 across the 6 study strains (P = 0.71) and between the 3 susceptible and the 3 resistant 38 strains (P=0.09). Three phenomena may contribute to explain this unexpected in vivo 39 activity: i) in mice, fosfomycin kidney/plasma concentrations ratio increased from 1 to 7.8 40 (95% CI, 5.2; 10.4) within 24 hours; in vitro, when pH decreased to 5: (ii) fosfomycin MICs 41 for the 3 resistant strains (64-256 µg/ml) decreased into the susceptible range (16-32 42 µg/ml) and: iii) maximal growth rates significantly decreased for all strains and were the 43 lowest in urine. These results suggest that local fosfomycin concentrations and 44 physiological conditions may favour fosfomycin activity in pyelonephritis, even against 45 resistant strains. 46 47 48

show abstract

Metabolic Adaptations of Uropathogenic E. coli in the Urinary Tract

Cited by 98 publications

References 110 publications

The Effect of Urine Concentration and pH on the Growth of Escherichia Coli in Canine Urine In Vitro

The Effect of Urine Concentration and pH on the Growth of Escherichia Coli in Canine Urine In Vitro

Ciprofloxacin, amoxicillin, and aminoglycosides stimulate genetic and phenotypic changes in uropathogenic Escherichia coli strains

Unexpected activity of oral fosfomycin against resistant strains ofEscherichia coliin murine pyelonephritis

Contact Info

Product

Resources

About