Patients with a urine culture yielding significant growth of uropathogens in the absence of any symptoms attributable to infection are defined as having asymptomatic bacteriuria. A relapsed UTI is defined as prompt recurrence of the same organism following treatment.
- Navigation menu.
- The Handbook of Political Sociology: States, Civil Societies, and Globalization.
- Urinary tract infection - Wikipedia;
- Want to read more?!
A complicated UTI is defined as an infection that is associated with structural or functional abnormalities of the genitourinary tract, or presence of an underlying disease that increases the risk for acquiring an infection or of failing therapy 22 - Conventionally, UTIs have been classified as lower or upper, uncomplicated or complicated and urosepsis.
In order to provide clinicians and researchers with a standardized tool and nomenclature for UTI, an improvised system of classification based on four characteristics consisting of anatomical levels of infection, grades of severity, presence of underlying risk factors, and the microbiological findings of UTI as suggested by European Association of Urology is shown in Table 2. The basis of this classification and its interpretation are also shown in the same table as an appendix Application of this classification to transplant recipients will require minor modification in the risk factor category since all immunocompromised recipients are at increased risk for UTI, and the absence of risk factors will not apply to recipients of SOT.
This new classification system would facilitate standardization of the diagnosis and treatment of UTI, and will also help to assess the impact of UTI on outcomes in transplant recipients. The risk factors for the development of posttransplant UTI are multifactorial and are determined by the interaction between host factors, pathologic agents and anatomical abnormalities.
Even though the risk of UTI in transplant recipients is determined by the net state of immunosuppression, certain immunosuppressants have a greater effect on the risk for UTI. Antimetabolite azathioprine or mycophenolate mofetil based regimens that predispose to bone marrow suppression, and induction therapy with cell depleting antibodies such as antithymocyte globulin have been reported to have higher incidence of UTI 3 , 30 , Any instrumentation and its duration is an important risk factor for UTI. Fayek et al. Diabetes mellitus has also been shown to increase the risk of bacterial UTI in some studies but the data are conflicting.
However, diabetes mellitus has strong association with fungal UTI typically caused by Candida albicans 3. CMV which increase the net state of immunosuppression Staphylococcus saprophyticus. Unusual pathogens of the urinary tract include M.
- Urinary tract infection.
- ESCMID: Other guidelines;
- Alpha Force: Black Gold: Book 9;
- American Journal of Infectious Diseases;
Candida species are the most common fungal cause of urinary tract infection in renal transplant recipients. As is the case with asymptomatic bacteriuria, there are no established diagnostic tests that reliably distinguish infection from colonization in patients with asymptomatic candiduria; no studies have unequivocally established the importance of pyuria or quantitative urine cultures for UTI due to candida. With widespread use of antibiotics for prevention and treatment in transplant recipients, the prevalence of resistance to antibiotics among uropathogenic bacteria is increasing.
Frequent use of antibiotics for treatment of asymptomatic bacteriuria also has been associated with antimicrobial resistance. In a study of patients with asymptomatic E. Outbreaks of organisms resistant to all commonly available antibiotics have occurred; treatment options may be restricted to nephrotoxic agents such as colistin The prevalence of drug resistance varies considerably by region and country. Virulence structures, like P fimbriae, are expressed on the surface of uropathogenic bacteria and facilitate adhesion to uroepithelial surface.
In transplant pyelonephritis, acute elevations in creatinine are commonly observed, though may improve with treatment More controversial is the effect of asymptomatic bacteriuria in renal transplantation. The concern remains that at least in a subset of patients, asymptomatic bacteriuria may represent a pathologic state: 1 While not well documented, asymptomatic bacteriuria early after renal transplantion may be a risk factor for development of symptomatic urinary tract infection, especially if bacteriuria is found repeatedly in association with pyuria Data, however, on the clinical significance of asymptomatic bacteriuria are conflicting; even less clear is the impact of antimicrobials on asymptomatic bacteriuria.
Common Questions About Recurrent Urinary Tract Infections in Women
Since urine culture is the key to the diagnosis of a UTI, specimen collection technique is important. Straight catheterization to obtain a urine specimen can be considered as an alternative. It is common practice for transplant centers to regularly screen asymptomatic renal transplant recipients for bacteriuria to initiate antimicrobial therapy. If a screening strategy for asymptomatic bacteriuria is chosen, we recommend limiting routine collection of urine cultures with an accompanying urinalysis with microscopy to the first 1—3 months after renal transplantation; thereafter, these screening tests could be performed only if symptoms or signs of infection develop or if elevations in creatinine are observed.
For women found to have bacteriuria, a second sample minimizing risk of contamination may be appropriate to document continued presence of bacteriuria. Not all organisms found in urine cultures are pathogens. For example, Staphylococcus epidermidis except in the presence of ureteral stents , lactobacillus, and Gardnerella vaginalis are unlikely to be pathogens. Urine cultures containing multiple organisms i. Other true pathogens may not grow well on routine culture media e.
The usefulness of leukocyte esterase and nitrite screening by dipstick has not been demonstrated in renal transplant recipients. Imaging with renal ultrasound or noncontrast CT scan should be considered to assess for complications such as obstruction and abscess, particularly in patients not fully responding to initial therapy or in patients with signs of severe infection. The overall treatment strategy depends on the severity of illness Table 4 ; Ref.
Selection of antimicrobial agents should be based on local epidemiological data and the patient's history of resistant organisms. It is important to be aware of the possibility of lack of correlation between signs and symptoms of UTI and the microbial load in immunocompromised patients. There is no consensus whether asymptomatic bacteriuria should be treated in renal transplant recipients and if so, at what time periods posttransplantation In a study of cases of asymptomatic E.
While treatment of asymptomatic bacteriuria is a common practice in renal transplant centers, the few available studies indicate that antimicrobials in this setting are often unsuccessful in sustaining sterilization of urine and have not been demonstrated to prevent subsequent UTI or improve graft function 44 , 52 - A treatment duration of 5—7 days could be considered.
More data are needed to guide these strategies. Guidelines of the Infectious Diseases Society of America recommend treatment of asymptomatic bacteriuria in pregnancy and immediately prior to transurethral resection of the prostate or other urologic procedures in which mucosal bleeding is anticipated in all persons, including nontransplant patients In patients with symptomatic UTI, removal preferred or replacement of urinary tract instruments such as urethral catheters and urologic stents is recommended.
In patients with signs of severe infection, choice of empiric antibiotic should take into account the patient's history of previous resistant organisms e.
Especially if resistant organisms are found, expanded antimicrobial testing should be requested from the microbiology lab to identify treatment options for completion of therapy e. Some authors recommend treatment of mild e. Others recommend that if the UTI occurs early posttransplant e. Transplant pyelonephritis or urosepsis warrants longer treatment, e.
Treatment of Urinary Tract Infections in Nonpregnant Women
Duration of treatment should be for at least 2 weeks, and should be extended until adequate drainage of abscesses and clinical resolution of infection has been achieved. Further research is necessary to determine whether asymptomatic candiduria warrants treatment in renal transplant patients as data on treatment of candiduria in renal transplantation are scant.
However, treatment of asymptomatic candiduria is generally discouraged unless the patient is undergoing a urologic procedure or is neutropenic Adjustments to calcineurin inhibitor dosages may be required with concurrent use of azole agents. Intravenous amphotericin B, 0. Continuous bladder irrigation with amphotericin B 50 mg diluted in 1 L of sterile water for 5—7 days may be less nephrotoxic but is of limited value given high relapse rates Voriconazole and echinocandins achieve low concentrations in the urinary collecting system, which reduces their usefulness for treatment of fungal urinary tract infection.
However, these agents may be able to penetrate kidney tissue and thus may have a role in transplant pyelonephritis; clinical experience is limited. Lipid formulations of amphotericin should not be used to treat UTI because of poor levels in urine Anatomic and functional abnormalities should be identified and corrected in renal transplant patients with recurrent symptomatic UTI Fig. Patients should be reminded of basic infection prevention measures, such as hydration, frequent voiding, and for females to void after sexual intercourse and wiping from front to back with toilet tissue.
Prostatitis should also be considered in the differential diagnosis. It should be remembered that posttransplant UTI may originate in the transplant or native kidneys, and imaging should include ureters and bladder to identify obstruction, renal calculi, retained foreign bodies, and complex cysts Voiding cystourethrograms, urodynamic studies, and cystoscopy should also be considered.
However, given how common reflux is in renal transplant recipients even in the absence of symptomatic UTI or asymptomatic bacteriuria, not all findings of reflux warrant surgical or endoscopic correction A schema of evaluation to identify a correctable abnormality is shown in Figure 2.
Some authors recommend treatment of relapsed, symptomatic UTI with 4—6 weeks of antibiotic therapy If this fails, other strategies to prevent recurrent symptomatic UTI include topical vaginal estrogen in postmenopausal women. Trials have yielded mixed results regarding efficacy of concentrated cranberry tablets for prevention of recurrent symptomatic UTI in nonrenal transplant recipients The potential benefits of extended antibiotic prophylaxis e. Prevention of UTI should receive highest priority with a particular attention given to treatment of existing infections, and correction of structural abnormalities of the urinary tract when present in the potential recipients prior to transplantation.
Neurogenic bladder, and in children, voiding dysfunction should be considered and addressed Transmission of infection via implantation of a contaminated organ is a potentially serious complication of SOT. Although, the optimal management of positive organ preservation fluid cultures is uncertain, increasing evidence suggests that organisms found in these cultures can subsequently cause infection in the recipient, and thus treatment can lead to improved outcomes However, for patients who are allergic to trimethoprim—sulfamethoxazole, the recommended alternative agent would be nitrofurantoin in an effort to limit the emergence of fluoroquinolone resistance Consider donor origin of UTI in the immediate postoperative period; recognition may require culture of preservative fluid for KTs II 2 25 , In KT recipients, limit the duration of instrumentation, catheters and stents 64 , Removal of ureteral stents within 4 weeks of renal transplantation is suggested III Urine culture collection technique is important.
In patients unable to perform these steps, straight catheterization to obtain a urine specimen can be considered. The duration of treatment for symptomatic UTI is 5—14 days, depending on the severity of illness. The efficacy of short course antibiotic therapy single dose or 3 days is unproven and not recommended in transplant recipients III 36 , 56 , Assess the true impact of UTI on patient and graft outcome using a standardized definition and classification both in the early and late post transplant period.
Monitor outcomes of asymptomatic bacteriuria with and without treatment during first 3 months after transplantation in kidney and other SOT recipients. Evaluate the changing microbiological profile of UTI in transplant recipients with newer immunosuppressive agents. Eligibility criteria included: i presenting with UTI symptoms, and ii the provision of informed written consent. Exclusion criteria included women with a history of current renal disease or known urinary tract abnormalities, as well as recent in-patient hospitalisation or the use of antimicrobial agents within the previous month.
We recorded the antimicrobial agents used to treat the presumptive UTIs on a laboratory tracker form that accompanied the MSU sample to the laboratory. Clinicians received antimicrobial susceptibility results only for those cases in which a urinary pathogen was isolated and determined to be resistant to the dispensed antimicrobial agent. Inoculated plates were incubated for 18 hours at 35 - 37 o C and then inspected for bacterial growth.
If 2 different bacterial colony types were present in equal numbers, both were purified for further laboratory work. Bacterial strains were archived at o C in Microbank storage vials Pro-Lab Diagnostics, Canada for the study duration. Bacterial species were first suspended in 2 ml 0. A cotton-tipped swab was used to inoculate appropriate media Diagnostics Media Products, SA with the bacterial suspension. After recruitment had been completed, we performed additional Etest-based minimum inhibitory concentration MIC assays for 2 further antimicrobial agents, fosfomycin and nitrofurantoin, using bacterial isolates cultured from o C stock vials in the same manner as described above.
Since enterococci are inherently non-susceptible to cephalosporins, they were reported as such, regardless of MIC value. Data were entered into a Microsoft Access database and analysed using Microsoft Excel. We determined the MIC 50 and MIC 90 values for each antimicrobial agent and investigated associations between variables of interest using the chi-squared test. The mean participant age was lower at the public sector facility The age range of recruited participants did not differ markedly by facility type 18 - 74 v.
Almost all participants attending the public facility were black Africans ; The frequency distribution of detected urine dipstick abnormalities and UTI-related clinical symptoms is shown in Table 1. There were no other significant associations between UTI pathogen isolation and the other diagnostic criteria listed in Table 1. At the public facility, ciprofloxacin ; Antimicrobial prescribing was more varied at the private practice facilities for the Ciprofloxacin was the most frequent therapeutic choice 76; Within the laboratory we processed We isolated bacteria in significant numbers in Culture of the MSU samples of 2 patients grew Gram-positive bacteria, Kocuria kristinae and Pediococcus pentosaceus , that we regarded as skin and vaginal commensals rather than UTI pathogens.
Accordingly, we did not include these 2 isolates in the antimicrobial susceptibility analyses. After excluding the 2 commensal isolates described above, we identified a total of UTI pathogens in participants Table 2.
Volume Issue Supplement_1 | The Journal of Infectious Diseases | Oxford Academic
In terms of Gram-stain morphotype, There was a significantly higher prevalence of E. A few of the bacterial isolates were not available for post-recruitment susceptibility testing with fosfomycin 2 isolates and nitrofurantoin 10 isolates. Overall, the UTI pathogens were most susceptible to fosfomycin This study describes the aetiology of community-acquired UTIs in women presenting to public and private facilities in Gauteng Province. In keeping with the existing literature, most bacterial isolates were GNB including E.
Community-acquired UTIs continue to represent a financial burden for many countries and short-course treatments are favoured, where possible, as resistance develops less commonly. Within SA, most community-acquired UTIs are treated empirically without the need for laboratory investigation and susceptibility testing of isolated UTI pathogens.
Maartens and Oliver 11 undertook a similar microbiological study of community-acquired UTI pathogens to determine the prevalence of antimicrobial resistance in Cape Town, SA. Our data confirm the rising prevalence of fluoroquinolone resistance among community-acquired UTI pathogens in SA. Fosfomycin has a broad antibacterial spectrum and inhibits phosphoenolpyruvate transferase, the first enzyme involved in peptidoglycan synthesis.