Probiotics [LGG-BB12 or RC14-GR1] versus placebo as prophylaxis for urinary tract infection in persons with spinal cord injury [ProSCIUTTU]: a randomised controlled trial

© 2019, The Author(s). Study design: Randomised double-blind factorial-design placebo-controlled trial. Objective: Urinary tract infections (UTIs) are common in people with spinal cord injury (SCI). UTIs are increasingly difficult to treat due to emergence of multi-resistant organisms. Probiotics are efficacious in preventing UTIs in post-menopausal women. We aimed to determine whether probiotic therapy with Lactobacillus reuteri RC-14+Lactobacillus GR-1 (RC14-GR1) and/or Lactobacillus rhamnosus GG+Bifidobacterium BB-12 (LGG-BB12) are effective in preventing UTI in people with SCI. Setting: Spinal units in New South Wales, Australia with their rural affiliations. Methods: We recruited 207 eligible participants with SCI and stable neurogenic bladder management. They were randomised to one of four arms: RC14-GR1+LGG-BB12, RC14-GR1+placebo, LGG-BB12+ placebo or double placebos for 6 months. Randomisation was stratified by bladder management type and inpatient or outpatient status. The primary outcome was time to occurrence of symptomatic UTI. Results: Analysis was based on intention to treat. Participants randomised to RC14-GR1 had a similar risk of UTI as those not on RC14-GR1 (HR 0.67; 95% CI: 0.39–1.18; P = 0.17) after allowing for pre-specified covariates. Participants randomised to LGG-BB12 also had a similar risk of UTI as those not on LGG-BB12 (HR 1.29; 95% CI: 0.74–2.25; P = 0.37). Multivariable post hoc survival analysis for RC14-GR1 only vs. the other three groups showed a potential protective effect (HR 0.46; 95% CI: 0.21–0.99; P = 0.03), but this result would need to be confirmed before clinical application. Conclusion: In this RCT, there was no effect of RC14-GR1 or LGG-BB12 in preventing UTI in people with SCI

Physicochemical and biochemical characterization of biosurfactants released by Lactobacillus strains

Biosurfactants from Lactobacillus casei subsp. rhamnosus 36 and ATCC 7469, Lactobacillus fermentum B54 and Lactobacillus acidophilus RC14 were isolated from bacteria in their mid-exponential (4-5 h) and stationary growth phases (18 h) and physicochemical and biochemical properties of the freeze-dried biosurfactants from both growth phases were compared. The mid-exponential and stationary phase biosurfactants were similar in their surface activities, but the latter had a lower and better defined critical micelle concentration. In particular, the stationary phase biosurfactant from L. acidophilus RC14 reached a low liquid surface tension of 39 mJ m(-2) in phosphate buffered saline, with a critical micelle concentration of 1.0 mg ml(-1). All biosurfactants consisted of a mixture of protein and polysaccharides, possibly containing bound phosphate groups, but the stationary phase biosurfactants were richest in protein, as concluded from Fourier transform infrared spectroscopy on biosurfactants in KBr pellets and from X-ray photoelectron spectroscopy on biosurfactants deposited on gold-coated glass slides. Infrared spectra of mid-exponential phase biosurfactants showed an absorption band around 2500 cm(-1), which was absent in the spectra of stationary phase biosurfactants and was assigned to nitrogen-containing compounds with >NH2+, >(NH+)-, or =(NH+)- groups. Amino acid analysis of the hydrolyzed mid-exponential and stationary phase biosurfactants from L. casei subsp. rhamnosus 36 demonstrated a high occurrence of alanine, which is possibly present as the free amino acid. The L. acidophilus RC14 mid-exponential phase biosurfactant also had a high alanine content, but the L. acidophilus RC14 stationary phase biosurfactant had an approximately four-fold lower alanine occurrence. We suggest that the protein-rich biosurfactants released by certain Lactobacillus strains in their stationary growth phases may interfere with uropathogen adhesion, for which we propose the name ''surlactin''

Inhibition of initial adhesion of uropathogenic Enterococcus faecalis by biosurfactants from Lactobacillus isolates

In this study, 15 Lactobacillus isolates were found to produce biosurfactants in the mid-exponential and stationary growth phases. The stationary-phase biosurfactants from Lactobacillus casei subsp. rhamnosus 36 and ATCC 7469, Lactobacillus fermentum B54, and Lactobacillus acidophilus RC14 were investigated further to determine their capacity to inhibit the initial adhesion of uropathogenic Enterococcus faecalis 1131 to glass in a parallel-plate flow chamber, The initial deposition rate of E. faecalis to glass with an adsorbed biosurfactant layer from L. acidophilus RC14 or L. fermentum B54 was significantly decreased by approximately 70%, while the number of adhering enterococci after 4 h of adhesion was reduced hy an average of 77%, The surface activity of the biosurfactants and their activity inhibiting the initial adhesion of E. faecalis 1131 were retained after dialysis (molecular weight cutoff, 6,000 to 8,000) and freeze-drying, Fourier transform infrared spectroscopy and ii-ray photoelectron spectroscopy revealed that the freeze-dried biosurfactants from L. acidophilus RC14 and L. fermentum B54 were richest in protein, while those from L. casei subsp, rhamnosus 36 and ATCC 7469 had relatively high polysaccharide and phosphate contents

Inhibition of initial adhesion of uropathogenic Enterococcus faecalis to solid substrata by an adsorbed biosurfactant layer from Lactobacillus acidophilus

Objectives. The potency of the Lactobacillus acidophilus RC14 biosurfactant ''surlactin'' to reduce the initial adhesion of Enterococcus faecalis 1131 was investigated on a hydrophilic and a hydrophobic substratum in a parallel-plate flow chamber, using phosphate-buffered saline and pooled human urine as a suspending fluid. Methods. A parallel-plate flow chamber with a glass or silicone rubber bottom plate was filled with different biosurfactant solutions of 0, 0.01, 0.1, or 1.0 mg/mL for overnight adsorption (18 hours). Subsequently, the adhesion of E. faecalis on thus prepared biosurfactant layers was observed in situ in phosphate-buffered saline or in urine by automated image analysis. Results. Adsorbed biosurfactant layers caused an important, dose-related inhibition of the initial deposition rate of E. faecalis and the number of adherent bacteria after 4 hours on both hydrophilic glass and hydrophobic silicone rubber, although this effect was stronger in buffer than in urine. For the experiments carried out in urine, the inhibitory effect of the biosurfactant layer was largest when silicone rubber was used rather than glass, whereas no influence of the substratum hydrophobicity on the inhibition of E. faecalis adhesion was noticed for experiments performed in buffer. Conclusions. The biosurfactant surlactin, as released by several Lactobacillus isolates, might open the way to the development of antiadhesive biologic coatings for catheter materials. It should be considered, however, that these results are preliminary and that the efficiency of the biosurfactant is probably affected not only by the hydrophobicity of the substratum and the suspending fluid, but also by the type of uropathogen involved. (C) 1997, Elsevier Science Inc