Project description:Long term-catheterization leads inevitably to a catheter-associated bacteriuria caused by multispecies bacterial biofilms growing on and in the catheters. The overall goal of the presented study was (I) to unravel bacterial community structure and function of such an uropathogenic biofilm and (II) to elucidate the interplay between bacterial virulence and the human immune system within the urine. To this end, a metaproteomics approach combined with in vitro proteomics analyses was employed to investigate both, the pro- and eukaryotic protein inventory. Our proteome analyses demonstrated that the biofilm of the investigated catheter is dominated by three bacterial species, i.e. Pseudomonas aeruginosa, Morganella morganii and Bacteroides sp., and identified iron limitation as one of the major challenges in the bladder environment. In vitro proteome analysis of P. aeruginosa and M. morganii isolated from the biofilm revealed that those opportunistic pathogens are able to overcome iron restriction via the production of siderophores and high expression of corresponding receptors. Notably, a comparison of in vivo and in vitro protein profiles of P. aeruginosa and M. morganii also indicated that the bacteria employ different strategies to adapt to the urinary tract. Whilst P. aeruginosa seems to express secreted and surface-exposed proteases to escape the human innate immune system and metabolizes amino acids, M. morganii is able to take up sugars and to degrade urea. Most interestingly, a comparison of urine protein profiles of three long-term catheterized patients and three healthy control persons demonstrated the elevated level of proteins associated to neutrophils, macrophages and complement system in the patient urine, which might point to a specific activation of the innate immune system in response to biofilm-associated urinary tract infections. We thus hypothesize that the often asymptomatic nature of CAUTI´s might be based on a fine-tuned balance between the expression of bacterial virulence factors and the human immune system. Long term-catheterization leads inevitably to a catheter-associated bacteriuria caused by multispecies bacterial biofilms growing on and in the catheters. The overall goal of the presented study was (I) to unravel bacterial community structure and function of such an uropathogenic biofilm and (II) to elucidate the interplay between bacterial virulence and the human immune system within the urine. To this end, a metaproteomics approach combined with in vitro proteomics analyses was employed to investigate both, the pro- and eukaryotic protein inventory. Our proteome analyses demonstrated that the biofilm of the investigated catheter is dominated by three bacterial species, i.e. Pseudomonas aeruginosa, Morganella morganii and Bacteroides sp., and identified iron limitation as one of the major challenges in the bladder environment. In vitro proteome analysis of P. aeruginosa and M. morganii isolated from the biofilm revealed that those opportunistic pathogens are able to overcome iron restriction via the production of siderophores and high expression of corresponding receptors. Notably, a comparison of in vivo and in vitro protein profiles of P. aeruginosa and M. morganii also indicated that the bacteria employ different strategies to adapt to the urinary tract. Whilst P. aeruginosa seems to express secreted and surface-exposed proteases to escape the human innate immune system and metabolizes amino acids, M. morganii is able to take up sugars and to degrade urea. Most interestingly, a comparison of urine protein profiles of three long-term catheterized patients and three healthy control persons demonstrated the elevated level of proteins associated to neutrophils, macrophages and complement system in the patient urine, which might point to a specific activation of the innate immune system in response to biofilm-associated urinary tract infections. We thus hypothesize that the often asymptomatic nature of CAUTI´s might be based on a fine-tuned balance between the expression of bacterial virulence factors and the human immune system.

Project description:Long term-catheterization leads inevitably to a catheter-associated bacteriuria caused by multispecies bacterial biofilms growing on and in the catheters. The overall goal of the presented study was (I) to unravel bacterial community structure and function of such an uropathogenic biofilm and (II) to elucidate the interplay between bacterial virulence and the human immune system within the urine. To this end, a metaproteomics approach combined with in vitro proteomics analyses was employed to investigate both, the pro- and eukaryotic protein inventory. Our proteome analyses demonstrated that the biofilm of the investigated catheter is dominated by three bacterial species, i.e. Pseudomonas aeruginosa, Morganella morganii and Bacteroides sp., and identified iron limitation as one of the major challenges in the bladder environment. In vitro proteome analysis of P. aeruginosa and M. morganii isolated from the biofilm revealed that those opportunistic pathogens are able to overcome iron restriction via the production of siderophores and high expression of corresponding receptors. Notably, a comparison of in vivo and in vitro protein profiles of P. aeruginosa and M. morganii also indicated that the bacteria employ different strategies to adapt to the urinary tract. Whilst P. aeruginosa seems to express secreted and surface-exposed proteases to escape the human innate immune system and metabolizes amino acids, M. morganii is able to take up sugars and to degrade urea. Most interestingly, a comparison of urine protein profiles of three long-term catheterized patients and three healthy control persons demonstrated the elevated level of proteins associated to neutrophils, macrophages and complement system in the patient urine, which might point to a specific activation of the innate immune system in response to biofilm-associated urinary tract infections. We thus hypothesize that the often asymptomatic nature of CAUTIÂ´s might be based on a fine-tuned balance between the expression of bacterial virulence factors and the human immune system. Long term-catheterization leads inevitably to a catheter-associated bacteriuria caused by multispecies bacterial biofilms growing on and in the catheters. The overall goal of the presented study was (I) to unravel bacterial community structure and function of such an uropathogenic biofilm and (II) to elucidate the interplay between bacterial virulence and the human immune system within the urine. To this end, a metaproteomics approach combined with in vitro proteomics analyses was employed to investigate both, the pro- and eukaryotic protein inventory. Our proteome analyses demonstrated that the biofilm of the investigated catheter is dominated by three bacterial species, i.e. Pseudomonas aeruginosa, Morganella morganii and Bacteroides sp., and identified iron limitation as one of the major challenges in the bladder environment. In vitro proteome analysis of P. aeruginosa and M. morganii isolated from the biofilm revealed that those opportunistic pathogens are able to overcome iron restriction via the production of siderophores and high expression of corresponding receptors. Notably, a comparison of in vivo and in vitro protein profiles of P. aeruginosa and M. morganii also indicated that the bacteria employ different strategies to adapt to the urinary tract. Whilst P. aeruginosa seems to express secreted and surface-exposed proteases to escape the human innate immune system and metabolizes amino acids, M. morganii is able to take up sugars and to degrade urea. Most interestingly, a comparison of urine protein profiles of three long-term catheterized patients and three healthy control persons demonstrated the elevated level of proteins associated to neutrophils, macrophages and complement system in the patient urine, which might point to a specific activation of the innate immune system in response to biofilm-associated urinary tract infections. We thus hypothesize that the often asymptomatic nature of CAUTIÂ´s might be based on a fine-tuned balance between the expression of bacterial virulence factors and the human immune system.

Project description:Actinotignum massiliense, a Gram-positive, facultatively anaerobic coccoid rod, is a rare human pathogen able to infect the urinary tract and belongs to the order of Actinomycetales. We identified A. massiliense as a resident of microbial biofilms growing on indwelling urethral catheter surfaces that were isolated from two patients with neurogenic bladders. These catheter biofilms (CBs) also harbored common uropathogens such as Proteus mirabilis and Aerococcus urinae, supporting the notion that A. massiliense depends on other co-colonizing microbes for survival. We isolated the bacterium from an anaerobically grown culture of a clinical sample, identified the species by 16S rRNA gene sequencing and verified this result via shotgun proteomics. Bacterial proteomes were profiled from the in vitro grown strain and four clinical ‘in vivo’ samples. The quantified proteomes allowed us to infer metabolic pathways and virulence/survival factors of importance in the CB milieu. Two putative subtilisin-like proteases, two Rib/Esp surface antigen repeat-containing proteins, a papain-like cysteine protease and a metal/heme/oligopeptide uptake system were highly expressed in vivo, but less so in vitro. We predict these proteins to be critical for adhesion and growth in CBs attacked by the host’s innate immune system or to improve bacterial fitness. Mixed acid fermentation following uptake and metabolism of xylose and glucuronate, sugars highly represented in proteoglycans and glycoglycerolipids of the urothelial mucosa and, in the case of glucuronate, shed into urine via renal xenobiotic conjugates, is inferred to be a major pathway for A. massiliense to generate energy under microaerobic conditions in CBs. The bacteria also appear to have active pathways for storage and utilization of glycogen as a carbon resource. Finally, we identified a putative polyketide synthase which may generate a secondary metabolite that interacts with either the host or co-colonizing organisms to enable A. massiliense survival in CBs.

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Early and Late Removal of the Urinary Catheter After Rectum Resection

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