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Asymptomatic Bacteriuria & Risk of Urinary Tract Infection in Renal Transplants (ASB)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01349738
Recruitment Status : Unknown
Verified August 2011 by Rice, James C., M.D..
Recruitment status was:  Enrolling by invitation
First Posted : May 9, 2011
Last Update Posted : September 1, 2011
University of Alabama at Birmingham
Information provided by:
Rice, James C., M.D.

Brief Summary:
The goal of this research program is to understand the natural history of asymptomatic bacteriuria in the renal transplant patients, to determine if screening for asymptomatic bacteriuria and identification of key host characteristics and virulence factors present on uropathogenic bacteria identifies a sub-population of patients with asymptomatic bacteriuria that are at risk to develop symptomatic urinary tract infection. Ultimately, the knowledge obtained from this study will prevent inappropriate antibiotic use and may identify whether certain bacterial isolates predispose to renal allograft injury. We will test the hypothesis that (i) asymptomatic bacteriuria is common in the renal allograft recipient and (ii) that symptomatic urinary tract infection and renal allograft dysfunction do not occur unless key host susceptibility factors and uropathogenic bacterial virulence factors are present.

Condition or disease Intervention/treatment
Bacteriuria Urinary Tract Infections Asymptomatic Infections Transplantation Infection Drug: Antibiotic

Detailed Description:

Blood samples and urine cultures will be obtained from asymptomatic renal transplant clinic patients. If the urine culture is positive (> or = 105 cfu/ml), we will determine the host and bacterial virulence factors associated with asymptomatic bacteriuria (ASB) and compare these results to transplant patients that develop a symptomatic UTI. The patient's clinical information, laboratory data and the bacterial isolate responsible for the UTI will be collected at the time of their clinic visit and subsequently analyzed.

After the first visit (Day 0 after signing consent) blood and urine will be collected, subjects will be put into either ASB Positive or ASB Negative groups based upon the results of their urine culture. From that point, those who test into the ASB Negative group will have an additional urine culture, either by returning to the clinic or by sending a urine culture mailer kit, and if cultures remain negative, they will be discharged from the study after reviewing medications, adverse events and completing a urinary tract infection risk questionnaire.

For those who test into the ASB Positive group, those subjects will be monitored by the subject returning to the clinic on Day 10-14, at 1 month, 2 month, 3 month and 6 months for blood and urine collection, review of medications and adverse events, and completing a urinary tract infection risk questionnaire. Should the subject have symptoms of a UTI, the subject will be treated with the appropriate antibiotic for which the bacterial isolated from their urine culture is sensitive. Patients will return to the clinic 10-14 days later for a repeat urine culture, complete a urinary tract infection risk questionnaire, and have a repeat urine culture to confirm they are urinary tract infection free. At this point, the subject will be discharged from the study after reviewing medications and adverse events.

It is predicted that 75% of patients will test into the ASB Negative Group and do not require antibiotic therapy. We predict that 25% of patients will test into the ASB Positive Group, but that less than 5% of these patients will ultimately develop a symptomatic UTI and require antibiotic treatment.

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Study Type : Observational
Estimated Enrollment : 200 participants
Observational Model: Case Control
Time Perspective: Prospective
Official Title: Asymptomatic Bacteriuria & Risk of Urinary Tract Infection in Renal Transplants
Study Start Date : May 2011
Estimated Study Completion Date : May 2013

Resource links provided by the National Library of Medicine

Group/Cohort Intervention/treatment
Positive Group
Positive for ASB
Drug: Antibiotic
Antibiotic (drug) sensitive to most recent culture for these subjects testing ASB positive and also experience Signs and symptoms of a UTI
Other Names:
  • Trimethoprim sulfamethoxazole (Bactrim)
  • Levofloxacin (Levaquin)
  • Ampicillin
  • Organism >100,000 col/ml Escherichia coli (presumptive)
  • Susceptibility type MIC (BY VITEK 2)
  • Ampicillin >=32 Resistant
  • Ampicillin/Sulbactam 16 Intermediate
  • Cefazolin <=4 Suscep.
  • Ciprofloxacin <=0.25 Suscep.
  • Gentamicin <=1 Suscep.
  • Levofloxacin <=0.12 Suscep.
  • Nitrofurantoin <=16 Suscep.
  • Tobramycin <=1 Suscep.
  • Trimeth-Sulfa >=16/304 Resistant

Negative Group
Negative for ASB

Primary Outcome Measures :
  1. Prevalence of Asymptomatic Bacteriuria and Risk of Developing Symptomatic Urinary Tract Infections or Renal Allograft Injury in Renal Transplant Patients [ Time Frame: 2 years ]
    Determine the prevalence and natural history of asymptomatic bacteriuria (ASB) and the host factors associated with the development of symptomatic UTI in renal allograft recipients. We will enroll renal transplant recipients, perform urine cultures and follow all patients with ASB to determine the prevalence of ASB and the host characteristics associated with ASB and the development of symptomatic UTI.

Secondary Outcome Measures :
  1. Host Characteristics of Renal Transplant Patients with Asymptomatic Bacteriuria at Risk to Develop Symptomatic Urinary Tract Infection [ Time Frame: 2 years ]
    We will measure blood and urine immunoglobulin and cytokine levels in patients with ASB and symptomatic UTI to determine if these host's immune parameters predict the outcome of ASB, including the development of symptomatic UTI.

  2. Determine the characteristics of uropathogenic bacteria that cause acute allograft injury in renal transplant patients. [ Time Frame: 2 years ]
    We will determine the expression of key uropathogenic virulence factors, including P fimbriae, Dr adhesins, and mono-mannose-binding type 1 fimbriae, on E. coli isolated from RTPs with ASB to determine if strains that express such virulence factors are more likely to cause symptomatic UTI and AAI, compared to E. coli that do not express these virulence factors.

Biospecimen Retention:   Samples Without DNA
The investgators have a repository of bacteria specimens from transplant patients with UTI and plan to save bacteria from this study. The investigators will also plan to save discarded aliquots of supernatent of urine and discarded aliquots of blood, all samples from centrifuged specimens devoid of human cells.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Kidney Transplant Patients

Inclusion Criteria:

  • must be 18 years old or older,
  • had a kidney transplant,
  • be at least 30 days post operation.

Exclusion Criteria:

  • Pregnant women, those planning to become pregnant or nursing mothers;
  • Renal transplant patients less than 30 days post transplant; Use of an indwelling Foley catheter;
  • Patients without a renal transplant;
  • Patients having concurrent surgical/wound infection and presumed hematogenous dissemination for the urinary tract.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01349738

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United States, California
Scripps Green Hospital
La Jolla, California, United States, 92037
Sponsors and Collaborators
Rice, James C., M.D.
University of Alabama at Birmingham
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Principal Investigator: James C. Rice, MD Scripps

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Responsible Party: Dr. James C. Rice, Scripps Identifier: NCT01349738    
Other Study ID Numbers: ASB in Transplants
First Posted: May 9, 2011    Key Record Dates
Last Update Posted: September 1, 2011
Last Verified: August 2011
Additional relevant MeSH terms:
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Communicable Diseases
Urinary Tract Infections
Asymptomatic Infections
Urologic Diseases
Asymptomatic Diseases
Disease Attributes
Pathologic Processes
Anti-Bacterial Agents
Antibiotics, Antitubercular
Anti-Infective Agents
Antitubercular Agents
Anti-Infective Agents, Urinary
Renal Agents
Topoisomerase II Inhibitors
Topoisomerase Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Antineoplastic Agents
Cytochrome P-450 CYP1A2 Inhibitors
Cytochrome P-450 Enzyme Inhibitors