Acute Pyelonephritis Associated with Bacteriuria During Long-Term Catheterization: A Prospective Clinicopathological Study

Warren, John W.; Muncie, Herbert L.; Hall-Craggs, Mary

doi:10.1093/infdis/158.6.1341

Cited by 99 publications

(32 citation statements)

References 16 publications

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“…The onset of acute pyelonephritis has been described in postmortem studies of the elderly with indwelling catheters at the time of death (94). In the clinical setting, the removal of infected indwelling urinary catheters is one of the most effective methods used to resolve bacteriuria and CAUTIs (3,95).…”

Section: Discussionmentioning

confidence: 99%

Enterococcus faecalis Overcomes Foreign Body-Mediated Inflammation To Establish Urinary Tract Infections

et al. 2013

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Urinary catheterization elicits major histological and immunological changes that render the bladder susceptible to microbial invasion, colonization, and dissemination. However, it is not understood how catheters induce these changes, how these changes act to promote infection, or whether they may have any protective benefit. In the present study, we examined how catheter-associated inflammation impacts infection by Enterococcus faecalis, a leading cause of catheter-associated urinary tract infection (CAUTI), a source of significant societal and clinical challenges. Using a recently optimized murine model of foreign body-associated UTI, we found that the implanted catheter itself was the primary inducer of inflammation. In the absence of the silicone tubing implant, E. faecalis induced only minimal inflammation and was rapidly cleared from the bladder. The catheter-induced inflammation was only minimally altered by subsequent enterococcal infection and was not suppressed by inhibitors of the neurogenic pathway and only partially by dexamethasone. Despite the robust inflammatory response induced by urinary implantation, E. faecalis produced biofilm and high bladder titers in these animals. Induction of inflammation in the absence of an implanted catheter failed to promote infection, suggesting that the presence of the catheter itself is essential for E. faecalis persistence in the bladder. Immunosuppression prior to urinary catheterization enhanced E. faecalis colonization, suggesting that implant-mediated inflammation contributes to the control of enterococcal infection. Thus, this study underscores the need for novel strategies against CAUTIs that seek to reduce the deleterious effects of implant-mediated inflammation on bladder homeostasis while maintaining an active immune response that effectively limits bacterial invaders. U rinary catheterization is directly associated with 80% of hospital-acquired urinary tract infections (UTIs) (1). The insertion and presence of indwelling urinary catheters disrupt the normal mechanical and host defenses of the urinary tract, allow extracellular microbes access to the sterile environment of the bladder by ascending through the catheter lumen or from the urethral meatus along the catheter, and provide an additional surface for biofilm formation and the establishment of antibioticrecalcitrant chronic or recurrent infections (2-9). Even in the absence of microbial colonization, urinary catheterization was shown to be associated with histological and immunological alterations in the bladder, including urothelial damage and exfoliation, bladder wall edema, inflammatory cytokine production, immune cell infiltration, and mucosal lesions of the bladders and kidneys (7, 10-13) which can lead to bladder cancers (14, 15). However, there remains a need to uncover molecular details and the functional role of the catheter-induced host responses during bacterial colonization and catheter-associated UTIs (CAUTIs).We recently optimized a murine model of foreign body-associated UTI to inv...

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Section: Discussionmentioning

confidence: 99%

Enterococcus faecalis Overcomes Foreign Body-Mediated Inflammation To Establish Urinary Tract Infections

et al. 2013

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“…45,47,48 A blinded autopsy study of 75 elderly residents of LTCF showed that 38% of patients who had an indwelling urinary catheter at the time of death also had acute renal inflammation. 49 Thus, although a shorter course of antibiotics may be desirable to limit the emergence of resistance, 45 a longer course of antibiotics may be required to treat occult pyelonephritis. Many clinicians empirically start with parenteral antibiotics to cover occult bacteremia, 20 but the benefit of parenteral antibiotics is not wellestablished.…”

Section: Diagnosis and Treatment Of Cautimentioning

confidence: 99%

Role of biofilm in catheter-associated urinary tract infection☆

Trautner

Darouiche

2004

American Journal of Infection Control

352

263

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The predominant form of life for the majority of microorganisms in any hydrated biologic system is a cooperative community termed a "biofilm." A biofilm on an indwelling urinary catheter consists of adherent microorganisms, their extracellular products, and host components deposited on the catheter. The biofilm mode of life conveys a survival advantage to the microorganisms associated with it and, thus, biofilm on urinary catheters results in persistent infections that are resistant to antimicrobial therapy. Because chronic catheterization leads almost inevitably to bacteriuria, routine treatment of asymptomatic bacteriuria in persons who are catheterized is not recommended. When symptoms of a urinary tract infection develop in a person who is catheterized, changing the catheter before collecting urine improves the accuracy of urine culture results. Changing the catheter may also improve the response to antibiotic therapy by removing the biofilm that probably contains the infecting organisms and that can serve as a nidus for reinfection. Currently, no proven effective strategies exist for prevention of catheter-associated urinary tract infection in persons who are chronically catheterized.Health care providers have traditionally envisioned bacteria in their free-floating or planktonic state, and planktonic organisms have been the focus of traditional microbiologic methods of sampling and culture. 1 However, the predominant form of life for the majority of microorganisms in any hydrated biologic system, such as the human body, is a cooperative community termed a "biofilm." 2 A formal definition of biofilm includes 3 components: (1) adherence of the microorganisms, either to a surface or to each other; (2) a change in gene expression resulting in a different phenotype from the planktonic state; and (3) an extracellular matrix composed of host components and secreted bacterial products. 3,4 A functional definition of biofilm also includes the fact that biofilm results in chronic, persistent infections that are difficult to eradicate with antimicrobial therapy. 5 The relevance of biofilm to catheter-associated urinary tract infection (UTI) (CAU-TI) is that a foreign body, such as an indwelling urethral catheter, connecting a normally sterile, hydrated body site to the outside world will inevitably become colonized with microorganisms. 4 Thus, the central character in the story of CAUTI is really the biofilm on the urinary catheter. PATHOGENESIS OF URINARY CATHETER-ASSOCIATED BIOFILMThe pathogenesis of CAUTI is related to the susceptibility of inert catheter material to microbial colonization. On the surface of normal bladder mucosa, binding of bacteria triggers an NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript inflammatory response that results in an influx of neutrophils and sloughing of epithelial cells with bound bacteria. [6][7][8][9] Both processes contribute to clearance of the bacteria from the mucosal surface. In contrast, catheter surfaces have no inherent defense mechani...

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“…It is frequently isolated from elderly individuals undergoing long-term catherization 2 . Potentially serious complications arising from P. mirabilis infections include bladder and kidney stone formation, obstruction of catheters by formation of encrusting biofilms, and bacteremia (reviewed in ref.…”

Section: Introductionmentioning

confidence: 99%

mini-Tn7 insertion in bacteria with secondary, non-glmS-linked attTn7 sites: example Proteus mirabilis HI4320

Choi

Schweizer

2006

Nat Protoc

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We previously constructed a series of mini-Tn7 chromosome integration vectors that, when provided only with the site-specific transposition machinery, generally transpose to a naturally evolved, neutral attTn7 site that is located 25-bp downstream of the glmS gene. Here we provide a protocol for application of the mini-Tn7 system in Proteus mirabilis as an example of a bacterium with a secondary attTn7 site that is not linked to glmS but, in this case, located in the carAB operon. The procedure involves, first, cloning of the genes of interest into an appropriate mini-Tn7 vector; second, co-transfer of the recombinant mini-Tn7 vector and a helper plasmid encoding the Tn7 site-specific transposition pathway into P. mirabilis by transformation, followed by selection of insertion-containing strains; third, PCR verification of mini-Tn7 insertions; and last, optional Flp-mediated excision of the antibiotic-resistance selection marker present on the chromosomally integrated mini-Tn7 element. When transposon-containing cells are selected on rich medium, insertions occur at both attTn7 sites with equal efficiency and frequency. Because carA mutants are arginine and pyrimidine auxotrophs, single-site insertions at the glmS attTn7 sites can be obtained by selection on minimal medium. From start to verification of the insertion events, the whole procedure takes 5 d. This chromosome integration system in P. mirabilis provides an important tool for animal and biofilm studies based on this bacterium. Vectors are available for gene complementation and expression, gene fusion analyses and tagging with a green fluorescent protein (GFP)-encoding reporter gene. INTRODUCTIONProteus mirabilis is a common uropathogen that causes urinary tract infections in individuals with structural abnormalities of the urinary tract 1 . It is frequently isolated from elderly individuals undergoing long-term catherization 2 . Potentially serious complications arising from P. mirabilis infections include bladder and kidney stone formation, obstruction of catheters by formation of encrusting biofilms, and bacteremia (reviewed in ref.3). The bacterium has the propensity to ascend to the kidneys, where it is found more frequently than Escherichia coli 4 . Experimental animal model systems have been established for studies of ascending urinary tract infections 5,6 . Although P. mirabilis is amenable to genetic studies, and indeed most E. coli plasmid systems also work in this bacterium, recombinant studies in these animal models have been hampered by the lack of a chromosome integration system that would facilitate stable maintenance of recombinant constructs without the need for continued selection.We therefore sought to extend the use of the broad host-range mini-Tn7 system 7 to this bacterium, which would make a valuable addition to the repertoire of genetic tools that are currently available. A more detailed description of the mini-Tn7 system and its features can be found in the accompanying protocol 8 . The mini-Tn7 vectors are based on the well-cha...

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Acute Pyelonephritis Associated with Bacteriuria During Long-Term Catheterization: A Prospective Clinicopathological Study

Cited by 99 publications

References 16 publications

Enterococcus faecalis Overcomes Foreign Body-Mediated Inflammation To Establish Urinary Tract Infections

Enterococcus faecalis Overcomes Foreign Body-Mediated Inflammation To Establish Urinary Tract Infections

Role of biofilm in catheter-associated urinary tract infection☆

mini-Tn7 insertion in bacteria with secondary, non-glmS-linked attTn7 sites: example Proteus mirabilis HI4320

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