An in-vitro model for bacteria-related catheter encrustations.

PURPOSE: About 50% of individuals with long-term indwelling catheters are affected by catheter encrustations and bladder stone formation. Therefore, prophylaxis of catheter encrustations is important. Currently, however, neither an established prophylaxis nor a standardized in-vitro model to test different measures exist. We have therefore developed and qualitatively evaluated an in-vitro model of catheter encrustation. METHODS: Size 14 French suprapubic catheters were incubated under sterile conditions at 37 degrees Celsius in five different media: (1) sterile artificial urine (n = 16), (2) artificial urine with E. coli (n = 8), (3) with Pseudomonas aeruginosa (n = 8), (4) with Proteus mirabilis (n = 8), and (5) with a mix of these three strains (n = 8). Catheter balloons were inflated either a glycerine or a bactericidal solution. After 6 weeks, the catheters were removed from the solution, dried, and weighed, and a photometric determination of the retrieved encrustations was performed. RESULTS: Most frequently and pronounced encrustations were detected in the Pseudomonas group. The median weight of these encrustations (50% struvite and brushite) was 84.4 mg (47.7 mg / 127.3 mg). Even on catheters stored in sterile urine, encrustations (69.2% struvite) were found. Bacterial growth was not affected by the medium used for catheter blockage. CONCLUSION: Although in-vitro models appear to be limited because they lack "the human factor", they are valuable for systematically assessing physico-chemical factors affecting encrustations. Therefore, our model, being reliable and cost-effective, may foster further research despite its limitations.

Changes in Bacterial Spectrum and Resistance Patterns Over Time in the Urine of Patients with Neurogenic Lower Urinary Tract Dysfunction Due to Spinal Cord Injury.

INTRODUCTION: Urinary tract infections (UTI) are among the most common complications in persons with neurogenic lower urinary tract dysfunction (NLUTD) due to spinal cord injury (SCI). As both asymptomatic bacteriuria and UTI are frequently treated with antibiotics, concerns about multidrug resistance arise. Therefore, we analyzed the bacterial spectrum in the urine and the resistance patterns of the strains over time in patients with NLUTD due to SCI. METHODS: In a systematic chart review, we identified all microbiologic urine test results including resistance patterns of persons with SCI in a tertiary referral hospital at 2 time periods (2010-2011 and 2017-2018). We assessed the frequency of the bacterial strains, the resistance patterns of the 5 most frequent bacteria, and the use of antibiotics for in- as well as for outpatients. RESULTS: From 2010 to 2011, 1,308 (outpatients) and 2,479 (inpatients) bacterial strains were detected in the urinalyses performed; these numbers rose to 3,162 and 6,112 during 2017-2018, respectively. The most frequently detected bacteria during both time periods were Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae/variicola, Streptococcus viridans, Pseudomonas aeruginosa, and coagulase negative Staphylococci. Fluoroquinolones were the most frequently used antibiotics during both time periods. Despite its frequent use, no relevant increase in resistance against fluoroquinolones was detected. The most prominent increase in resistance appeared in E. coli against amocixillin/clavulanic acid in inpatients (from 26.0 to 38.5%). DISCUSSION AND CONCLUSIONS: Although fluoroquinolones were used frequently, we did not observe an increased resistance against these antibiotics over time in the urine of patients with SCI.

In Vitro Effects of Homeopathic Drugs on Cultured Escherichia coli.

BACKGROUND: Recurrent urinary tract infections (UTIs) are one of the most common morbidities in persons with neurogenic lower urinary tract dysfunction (NLUTD). Repetitive antibiotic treatment increases the risk of selecting multi-resistant bacteria. Homeopathic treatment has been reported to be effective in these patients. The mechanism of action, however, has not been clarified. Recently, a direct bactericidal effect of homeopathic remedies was shown. Such an effect is not in accordance with the general principles of homeopathy. To test this paradigm, we assessed the in vitro effects of homeopathic drugs on Escherichia coli derived from patients with NLUTD. METHODS: E. coli bacteria were harvested from 28 consecutive urine cultures. Standard antibiotic resistance testing and simultaneous resistance testing to homeopathic drugs (Apis mellifica, Cantharis, Causticum hahnemanni, Staphysagria, Nux vomica, Berberis vulgaris, and Lycopodiumclavatum) in high (C30) potency were performed. RESULTS: No significant inhibitory effect of any of the tested homeopathic drugs on any E. coli population could be found, irrespective of their sensitivity to antibiotic treatment. CONCLUSION: Based on our results, effects of homeopathic treatment of UTI are not based on direct bactericidal or bacteriostatic effects. These findings are in concordance with the hypothesis that homeopathy is based on host effects: for example, activation of the immune system, rather than effects on pathogens.