Asymptomatic Bacteriuria and Pyuria in Premenopausal Women.

BACKGROUND: Asymptomatic bacteriuria and pyuria in healthy women often trigger inappropriate antimicrobial treatment, but there is a paucity of data on their prevalence and persistence. METHODS: To evaluate the prevalence and persistence of asymptomatic bacteriuria and pyuria in women at high risk of recurrent urinary tract infection, we conducted an observational cohort study in 104 healthy premenopausal women with a history of recurrent urinary tract infection with daily assessments of bacteriuria, pyuria, and urinary symptoms over a 3-month period. RESULTS: The mean age of participants was 22 years, and 74% were white. Asymptomatic bacteriuria events (urine cultures with colony count ≥105 CFU/mL of a uropathogen on days with no symptomatic urinary tract infection diagnosed) occurred in 45 (45%) women on 159 (2.5%) of 6283 days. Asymptomatic bacteriuria events were most commonly caused by Escherichia coli, which was present on 1.4% of days, with a median duration of 1 day (range, 1-10). Pyuria occurred in 70 (78%) of 90 evaluable participants on at least 1 day and 25% of all days on which no symptomatic urinary tract infection was diagnosed. The positive predictive value of pyuria for E. coli asymptomatic bacteriuria was 4%. CONCLUSIONS: In this population of healthy women at high risk of recurrent urinary tract infection, asymptomatic bacteriuria is uncommon and, when present, rarely lasts more than 2 days. Pyuria, on the other hand, is common but infrequently associated with bacteriuria or symptoms. These data strongly support recommendations not to screen for or treat asymptomatic bacteriuria or pyuria in healthy, nonpregnant women.

Bacterial virulence phenotypes of Escherichia coli and host susceptibility determine risk for urinary tract infections.

Urinary tract infections (UTIs) are caused by uropathogenic Escherichia coli (UPEC) strains. In contrast to many enteric E. coli pathogroups, no genetic signature has been identified for UPEC strains. We conducted a high-resolution comparative genomic study using E. coli isolates collected from the urine of women suffering from frequent recurrent UTIs. These isolates were genetically diverse and varied in their urovirulence, that is, their ability to infect the bladder in a mouse model of cystitis. We found no set of genes, including previously defined putative urovirulence factors (PUFs), that were predictive of urovirulence. In addition, in some patients, the E. coli strain causing a recurrent UTI had fewer PUFs than the supplanted strain. In competitive experimental infections in mice, the supplanting strain was more efficient at colonizing the mouse bladder than the supplanted strain. Despite the lack of a clear genomic signature for urovirulence, comparative transcriptomic and phenotypic analyses revealed that the expression of key conserved functions during culture, such as motility and metabolism, could be used to predict subsequent colonization of the mouse bladder. Together, our findings suggest that UTI risk and outcome may be determined by complex interactions between host susceptibility and the urovirulence potential of diverse bacterial strains.

Performance of a New Rapid Immunoassay Test Kit for Point-of-Care Diagnosis of Significant Bacteriuria.

Urinary tract infections (UTIs) are frequently encountered in clinical practice and most commonly caused by Escherichia coli and other Gram-negative uropathogens. We tested RapidBac, a rapid immunoassay for bacteriuria developed by Silver Lake Research Corporation (SLRC), compared with standard bacterial culture using 966 clean-catch urine specimens submitted to a clinical microbiology laboratory in an urban academic medical center. RapidBac was performed in accordance with instructions, providing a positive or negative result in 20 min. RapidBac identified as positive 245/285 (sensitivity 86%) samples with significant bacteriuria, defined as the presence of a Gram-negative uropathogen or Staphylococcus saprophyticus at ≥10(3) CFU/ml. The sensitivities for Gram-negative bacteriuria at ≥10(4) CFU/ml and ≥10(5) CFU/ml were 96% and 99%, respectively. The specificity of the test, detecting the absence of significant bacteriuria, was 94%. The sensitivity and specificity of RapidBac were similar on samples from inpatient and outpatient settings, from male and female patients, and across age groups from 18 to 89 years old, although specificity was higher in men (100%) compared with that in women (92%). The RapidBac test for bacteriuria may be effective as an aid in the point-of-care diagnosis of UTIs especially in emergency and primary care settings.

Lipocalin 2 imparts selective pressure on bacterial growth in the bladder and is elevated in women with urinary tract infection.

Competition for iron is a critical component of successful bacterial infections, but the underlying in vivo mechanisms are poorly understood. We have previously demonstrated that lipocalin 2 (LCN2) is an innate immunity protein that binds to bacterial siderophores and starves them for iron, thus representing a novel host defense mechanism to infection. In the present study we show that LCN2 is secreted by the urinary tract mucosa and protects against urinary tract infection (UTI). We found that LCN2 was expressed in the bladder, ureters, and kidneys of mice subject to UTI. LCN2 was protective with higher bacterial numbers retrieved from bladders of Lcn2-deficient mice than from wild-type mice infected with the LCN2-sensitive Escherichia coli strain H9049. Uropathogenic E. coli mutants in siderophore receptors for salmochelin, aerobactin, or yersiniabactin displayed reduced fitness in wild-type mice, but not in mice deficient of LCN2, demonstrating that LCN2 imparts a selective pressure on bacterial growth in the bladder. In a human cohort of women with recurrent E. coli UTIs, urine LCN2 levels were associated with UTI episodes and with levels of bacteriuria. The number of siderophore systems was associated with increasing bacteriuria during cystitis. Our data demonstrate that LCN2 is secreted by the urinary tract mucosa in response to uropathogenic E. coli challenge and acts in innate immune defenses as a colonization barrier that pathogens must overcome to establish infection.

Inhibition of Cyclooxygenase-2 Prevents Chronic and Recurrent Cystitis.

The spread of multidrug-resistant microorganisms globally has created an urgent need for novel therapeutic strategies to combat urinary tract infections (UTIs). Immunomodulatory therapy may provide benefit, as treatment of mice with dexamethasone during acute UTI improved outcome by reducing the development of chronic cystitis, which predisposes to recurrent infection. Here we discovered soluble biomarkers engaged in myeloid cell development and chemotaxis that were predictive of future UTI recurrence when elevated in the sera of young women with UTI. Translation of these findings revealed that temperance of the neutrophil response early during UTI, and specifically disruption of bladder epithelial transmigration of neutrophils by inhibition of cyclooxygenase-2, protected mice against chronic and recurrent cystitis. Further, proteomics identified bladder epithelial remodeling consequent to chronic infection that enhances sensitivity to neutrophil damage. Thus, cyclooxygenase-2 expression during acute UTI is a critical molecular trigger determining disease outcome and drugs targeting cyclooxygenase-2 could prevent recurrent UTI.

Voided midstream urine culture and acute cystitis in premenopausal women.

BACKGROUND: The cause of acute uncomplicated cystitis is determined on the basis of cultures of voided midstream urine, but few data guide the interpretation of such results, especially when gram-positive bacteria grow. METHODS: Women from 18 to 49 years of age with symptoms of cystitis provided specimens of midstream urine, after which we collected urine by means of a urethral catheter for culture (catheter urine). We compared microbial species and colony counts in the paired specimens. The primary outcome was a comparison of positive predictive values and negative predictive values of organisms grown in midstream urine, with the presence or absence of the organism in catheter urine used as the reference. RESULTS: The analysis of 236 episodes of cystitis in 226 women yielded 202 paired specimens of midstream urine and catheter urine that could be evaluated. Cultures were positive for uropathogens in 142 catheter specimens (70%), 4 of which had more than one uropathogen, and in 157 midstream specimens (78%). The presence of Escherichia coli in midstream urine was highly predictive of bladder bacteriuria even at very low counts, with a positive predictive value of 10(2) colony-forming units (CFU) per milliliter of 93% (Spearman's r=0.944). In contrast, in midstream urine, enterococci (in 10% of cultures) and group B streptococci (in 12% of cultures) were not predictive of bladder bacteriuria at any colony count (Spearman's r=0.322 for enterococci and 0.272 for group B streptococci). Among 41 episodes in which enterococcus, group B streptococci, or both were found in midstream urine, E. coli grew from catheter urine cultures in 61%. CONCLUSIONS: Cultures of voided midstream urine in healthy premenopausal women with acute uncomplicated cystitis accurately showed evidence of bladder E. coli but not of enterococci or group B streptococci, which are often isolated with E. coli but appear to rarely cause cystitis by themselves. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases.).

Predictive diagnostics for Escherichia coli infections based on the clonal association of antimicrobial resistance and clinical outcome.

The ability to identify bacterial pathogens at the subspecies level in clinical diagnostics is currently limited. We investigated whether splitting Escherichia coli species into clonal groups (clonotypes) predicts antimicrobial susceptibility or clinical outcome. A total of 1,679 extraintestinal E. coli isolates (collected from 2010 to 2012) were collected from one German and 5 U.S. clinical microbiology laboratories. Clonotype identity was determined by fumC and fimH (CH) sequencing. The associations of clonotype with antimicrobial susceptibility and clinical variables were evaluated. CH typing divided the isolates into >200 CH clonotypes, with 93% of the isolates belonging to clonotypes with ≥ 2 isolates. Antimicrobial susceptibility varied substantially among clonotypes but was consistent across different locations. Clonotype-guided antimicrobial selection significantly reduced "drug-bug" mismatch compared to that which occurs with the use of conventional empirical therapy. With trimethoprim-sulfamethoxazole and fluoroquinolones, the drug-bug mismatch was predicted to decrease 62% and 78%, respectively. Recurrent or persistent urinary tract infection and clinical sepsis were significantly correlated with specific clonotypes, especially with CH40-30 (also known as H30), a recently described clonotype within sequence type 131 (ST131). We were able to clonotype directly from patient urine samples within 1 to 3 h of obtaining the specimen. In E. coli, subspecies-level identification by clonotyping can be used to significantly improve empirical predictions of antimicrobial susceptibility and clinical outcomes in a timely manner.

Abrupt emergence of a single dominant multidrug-resistant strain of Escherichia coli.

BACKGROUND: Fluoroquinolone-resistant Escherichia coli are increasingly prevalent. Their clonal origins--potentially critical for control efforts--remain undefined. METHODS: Antimicrobial resistance profiles and fine clonal structure were determined for 236 diverse-source historical (1967-2009) E. coli isolates representing sequence type ST131 and 853 recent (2010-2011) consecutive E. coli isolates from 5 clinical laboratories in Seattle, Washington, and Minneapolis, Minnesota. Clonal structure was resolved based on fimH sequence (fimbrial adhesin gene: H subclone assignments), multilocus sequence typing, gyrA and parC sequence (fluoroquinolone resistance-determining loci), and pulsed-field gel electrophoresis. RESULTS: Of the recent fluoroquinolone-resistant clinical isolates, 52% represented a single ST131 subclonal lineage, H30, which expanded abruptly after 2000. This subclone had a unique and conserved gyrA/parC allele combination, supporting its tight clonality. Unlike other ST131 subclones, H30 was significantly associated with fluoroquinolone resistance and was the most prevalent subclone among current E. coli clinical isolates, overall (10.4%) and within every resistance category (11%-52%). CONCLUSIONS: Most current fluoroquinolone-resistant E. coli clinical isolates, and the largest share of multidrug-resistant isolates, represent a highly clonal subgroup that likely originated from a single rapidly expanded and disseminated ST131 strain. Focused attention to this strain will be required to control the fluoroquinolone and multidrug-resistant E. coli epidemic.

Cefpodoxime vs ciprofloxacin for short-course treatment of acute uncomplicated cystitis: a randomized trial.

CONTEXT: Although fluoroquinolones remain the most reliable urinary antimicrobial, resistance rates have increased and effective fluoroquinolone-sparing antimicrobials are needed. OBJECTIVE: To determine whether cefpodoxime is noninferior to ciprofloxacin for treatment of acute cystitis. DESIGN, SETTING, AND PATIENTS: Randomized, double-blind trial of 300 women aged 18 to 55 years with acute uncomplicated cystitis comparing ciprofloxacin (n = 150) with cefpodoxime (n = 150); patients were from a student health center in Seattle, Washington, and a referral center in Miami, Florida. The study was conducted from 2005 to 2009 and outcomes were assessed at 5 to 9 days and 28 to 30 days after completion of therapy. Intent-to-treat and per-protocol analyses were performed; 15 women in the ciprofloxacin group and 17 women in the cefpodoxime group were lost to follow-up. INTERVENTIONS: Patients were given 250 mg of ciprofloxacin orally twice daily for 3 days or 100 mg of cefpodoxime proxetil orally twice daily for 3 days. MAIN OUTCOME MEASURES: Overall clinical cure (defined as not requiring antimicrobial treatment during follow-up) at the 30-day follow-up visit. Secondary outcomes were clinical and microbiological cure at the first follow-up visit and vaginal Escherichia coli colonization at each follow-up visit. The hypothesis that cefpodoxime would be noninferior to ciprofloxacin by a 10% margin (ie, for the difference in the primary outcome for ciprofloxacin minus cefpodoxime, the upper limit of the confidence interval would be <10%) was formulated prior to data collection. RESULTS: The overall clinical cure rate at the 30-day visit with the intent-to-treat approach in which patients lost to follow-up were considered as having clinical cure was 93% (139/150) for ciprofloxacin compared with 82% (123/150) for cefpodoxime (difference of 11%; 95% CI, 3%-18%); and for the intent-to-treat approach in which patients lost to follow-up were considered as having not responded to treatment, the clinical cure rate was 83% (124/150) for ciprofloxacin compared with 71% (106/150) for cefpodoxime (difference of 12%; 95% CI, 3%-21%). The microbiological cure rate was 96% (123/128) for ciprofloxacin compared with 81% (104/129) for cefpodoxime (difference of 15%; 95% CI, 8%-23%). At first follow-up, 16% of women in the ciprofloxacin group compared with 40% of women in the cefpodoxime group had vaginal E coli colonization. CONCLUSIONS: Among women with uncomplicated cystitis, a 3-day regimen of cefpodoxime compared with ciprofloxacin did not meet criteria for noninferiority for achieving clinical cure. These findings, along with concerns about possible adverse ecological effects associated with other broad-spectrum ß-lactams, do not support the use of cefpodoxime as a first-line fluoroquinolone-sparing antimicrobial for acute uncomplicated cystitis. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00194532.

Randomized, placebo-controlled phase 2 trial of a Lactobacillus crispatus probiotic given intravaginally for prevention of recurrent urinary tract infection.

BACKGROUND: Urinary tract infections (UTIs) are common among women and frequently recur. Depletion of vaginal lactobacilli is associated with UTI risk, which suggests that repletion may be beneficial. We conducted a double-blind placebo-controlled trial of a Lactobacillus crispatus intravaginal suppository probiotic (Lactin-V; Osel) for prevention of recurrent UTI in premenopausal women. METHODS: One hundred young women with a history of recurrent UTI received antimicrobials for acute UTI and then were randomized to receive either Lactin-V or placebo daily for 5 d, then once weekly for 10 weeks. Participants were followed up at 1 week and 10 weeks after intervention and for UTIs; urine samples for culture and vaginal swabs for real-time quantitative 16S ribosomal RNA gene polymerase chain reaction for L. crispatus were collected. RESULTS: Recurrent UTI occurred in 7/48 15% of women receiving Lactin-V compared with 13/48 27% of women receiving placebo (relative risk [RR], .5; 95% confidence interval, .2-1.2). High-level vaginal colonization with L. crispatus (≥10(6) 16S RNA gene copies per swab) throughout follow-up was associated with a significant reduction in recurrent UTI only for Lactin-V (RR for Lactin-V, .07; RR for placebo, 1.1; P < .01). CONCLUSIONS: Lactin-V after treatment for cystitis is associated with a reduction in recurrent UTI. Larger efficacy trials of this novel preventive method for recurrent UTI are warranted. CLINICAL TRIALS REGISTRATION. NCT00305227.

Family history and risk of recurrent cystitis and pyelonephritis in women.

PURPOSE: Recurrent urinary tract infections and pyelonephritis have risk factors suggesting genetic sources. Family history variables indicative of genetic risk merit further investigation. We evaluated the risk of recurrent cystitis and pyelonephritis in women with and those without a family history of urinary tract infection. MATERIALS AND METHODS: We conducted a population based case-control study of 1,261 women 18 to 49 years old enrolled in a Northwest health plan. Participants were cases identified from plan databases with documented recurrent cystitis (431) or pyelonephritis (400). Shared controls (430) were similar age women with no urinary tract infection history. We evaluated the history of urinary tract infection and pyelonephritis in first-degree female relatives (mother, sister[s], daughter[s]) and other covariates, ascertained through questionnaires and computerized databases. RESULTS: Of the cases 70.9% with recurrent cystitis and 75.2% with pyelonephritis, and of the controls 42.4% reported a urinary tract infection history in 1 or more female relative (p <0.001 for each case group vs controls). In both case groups odds ratios were significantly increased for women reporting a urinary tract infection history in their mother, sister(s) or daughter(s). Risk increased with a greater number of affected relatives. In women with 1 vs 2 or more relatives the ORs for recurrent cystitis were 3.1 (95% CI 2.1, 4.7) and 5.0 (3.1, 8.1), and the ORs for pyelonephritis were 3.3 (2.2, 5.0) and 5.5 (3.4, 9.0), respectively. CONCLUSIONS: In these community dwelling women a urinary tract infection history in female relatives was strongly and consistently associated with urinary tract infection recurrence and pyelonephritis. Risk estimates increased with stronger family history indices, suggesting a genetic component for increased susceptibility to these infections.

Toll-like receptor polymorphisms and susceptibility to urinary tract infections in adult women.

BACKGROUND: Although behavioral risk factors are strongly associated with urinary tract infection (UTI) risk, the role of genetics in acquiring this disease is poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: To test the hypothesis that polymorphisms in Toll-like receptor (TLR) pathway genes are associated with susceptibility to UTIs, we conducted a population-based case-control study of women ages 18-49 years. We examined DNA variants in 9 TLR pathway genes in 431 recurrent cystitis (rUTI) cases, 400 pyelonephritis cases, and 430 controls with no history of UTIs. In the Caucasian subgroup of 987 women, polymorphism TLR4_A896G was associated with protection from rUTI, but not pyelonephritis, with an odds ratio (OR) of 0.54 and a 95% confidence interval (CI) of 0.31 to 0.96. Polymorphism TLR5_C1174T, which encodes a variant that abrogates flagellin-induced signaling, was associated with an increased risk of rUTI (OR(95%CI): 1.81 (1.00-3.08)), but not pyelonephritis. Polymorphism TLR1_G1805T was associated with protection from pyelonephritis (OR(95%CI): 0.53 (0.29-0.96)). CONCLUSIONS: These results provide the first evidence of associations of TLR5 and TLR1 variants with altered risks of acquiring rUTI and pyelonephritis, respectively. Although these data suggest that TLR polymorphisms are associated with adult susceptibility to UTIs, the statistical significance was modest and will require further study including validation with independent cohorts.

Short-course nitrofurantoin for the treatment of acute uncomplicated cystitis in women.

BACKGROUND: There is a paucity of data on the efficacy of nitrofurantoin for the treatment of acute uncomplicated cystitis in regimens shorter than 7 days. Evidence-based use of this drug is increasingly important as trimethoprim-sulfamethoxazole resistance among uropathogens increases. METHODS: To assess the efficacy of nitrofurantoin vs trimethoprim-sulfamethoxazole, 338 women aged 18 to 45 years with acute uncomplicated cystitis were randomized to open-label treatment with either trimethoprim-sulfamethoxazole, 1 double-strength tablet twice daily for 3 days, or nitrofurantoin, 100 mg twice daily for 5 days. Clinical cure 30 days after therapy was the main outcome measure. Secondary outcomes included clinical and microbiological cure rates 5 to 9 days after therapy and, for trimethoprim-sulfamethoxazole-treated women, clinical cure stratified by the trimethoprim-sulfamethoxazole susceptibility of the uropathogen. RESULTS: Clinical cure was achieved in 79% of the trimethoprim-sulfamethoxazole group and in 84% of the nitrofurantoin group, for a difference of -5% (95% confidence interval, -13% to 4%). Clinical and microbiological cure rates at the first follow-up visit were also equivalent between the 2 groups. In the trimethoprim-sulfamethoxazole arm, 7 of 17 women (41%) with a trimethoprim-sulfamethoxazole-nonsusceptible isolate had a clinical cure compared with 84% of women with a trimethoprim-sulfamethoxazole-susceptible isolate (P < .001). CONCLUSION: A 5-day course of nitrofurantoin is equivalent clinically and microbiologically to a 3-day course of trimethoprim-sulfamethoxazole and should be considered an effective fluoroquinolone-sparing alternative for the treatment of acute cystitis in women.

Amoxicillin-clavulanate vs ciprofloxacin for the treatment of uncomplicated cystitis in women: a randomized trial.

CONTEXT: The high prevalence of resistance to trimethoprim-sulfamethoxazole and other antimicrobials among Escherichia coli causing acute cystitis in women has led to increased use of alternative antibiotics. One such antibiotic, amoxicillin-clavulanate, has not been well studied. OBJECTIVE: To compare the efficacy of a 3-day regimen of amoxicillin-clavulanate to that of a 3-day regimen of ciprofloxacin in the treatment of acute cystitis in women. The primary study hypothesis was that the amoxicillin-clavulanate and ciprofloxacin treatment groups would differ in clinical cure. DESIGN, SETTING, AND PATIENTS: Randomized, single-blind treatment trial of 370 women, aged 18 to 45 years, with symptoms of acute uncomplicated cystitis and a urine culture with at least 10(2) colony-forming units of uropathogens per milliliter from a university student health center or a health maintenance organization. INTERVENTIONS: Women were randomly assigned to receive amoxicillin-clavulanate (500 mg/125 mg twice daily) or ciprofloxacin (250 mg twice daily) for 3 days and were followed up for 4 months. MAIN OUTCOME MEASURES: The main outcome measure was clinical cure. Secondary study outcomes of interest were microbiological cure and vaginal E coli colonization at the 2-week follow-up visit. RESULTS: Clinical cure was observed in 93 (58%) of 160 women treated with amoxicillin-clavulanate compared with 124 (77%) of 162 women treated with ciprofloxacin (P<.001). Amoxicillin-clavulanate was not as effective as ciprofloxacin even among women infected with strains susceptible to amoxicillin-clavulanate (65 [60%] of 109 women in the amoxicillin-clavulanate group vs 114 [77%] of 149 women in the ciprofloxacin group; P = .004). The difference in clinical cure rates occurred almost entirely within the first 2 weeks after therapy. Microbiological cure at 2 weeks was observed in 118 (76%) of 156 women treated with amoxicillin-clavulanate compared with 153 (95%) of 161 women treated with ciprofloxacin (P<.001). At this visit, 45% of women in the amoxicillin-clavulanate group compared with 10% in the ciprofloxacin group had vaginal colonization with E coli (P<.001). CONCLUSIONS: A 3-day regimen of amoxicillin-clavulanate is not as effective as ciprofloxacin for the treatment of acute uncomplicated cystitis, even in women infected with susceptible strains. This difference may be due to the inferior ability of amoxicillin-clavulanate to eradicate vaginal E coli, facilitating early reinfection.

Risk factors associated with acute pyelonephritis in healthy women.

BACKGROUND: Although most cases of acute pyelonephritis occur in otherwise healthy women, data on risk factors for this condition are lacking. OBJECTIVE: To evaluate infection characteristics, incidence, and risk factors associated with acute pyelonephritis in a sample of women. DESIGN: Population-based case-control study. SETTING: Group Health Cooperative, a prepaid health plan in Washington. PARTICIPANTS: 788 nonpregnant women, 18 to 49 years of age. Case-patients (n = 242) were women with pyelonephritis who were identified from computerized databases. Controls were 546 similar-age women with no pyelonephritis diagnosis in the previous 5 years who were randomly selected from enrollment databases. Response rates for case-patients and controls were 73% and 64%, respectively. MEASUREMENTS: Characteristics of infection and potential risk factors for pyelonephritis, ascertained through computer-assisted telephone interview and computerized databases. RESULTS: 7% of case-patients were hospitalized. Escherichia coli was the infecting pathogen in 85% of cases. In multivariable models, factors associated with pyelonephritis risk were frequency of sexual intercourse in the previous 30 days (odds ratio, 5.6 [95% CI, 2.8 to 11.0] for > or =3 times per week), recent urinary tract infection (UTI) (odds ratio, 4.4 [CI, 2.8 to 7.1]), diabetes (odds ratio, 4.1 [CI, 1.6 to 10.9]), recent incontinence (odds ratio, 3.9 [CI. 2.6 to 5.9]), new sexual partner in the previous year (odds ratio, 2.2 [CI, 1.4 to 3.6]), recent spermicide use (odds ratio, 1.7 [CI, 1.1 to 2.8]), and UTI history in the participant's mother (odds ratio, 1.6 [CI, 1.1 to 2.5]). Risk factors for selected subgroups (patients < or = 30 years of age, patients > 30 years of age, patients with no UTI history, and inpatients) were also evaluated. LIMITATIONS: Potential recall bias, reliance on automated case definition criteria, and limited data on diabetes and incontinence variables. CONCLUSIONS: Few nonpregnant, community-dwelling women younger than 50 years of age with pyelonephritis are hospitalized. As with cystitis in reproductive-age women, sexual behaviors and patient and family history of UTI are associated with increased pyelonephritis risk. Diabetes and incontinence also seem to independently increase the risk for pyelonephritis.

Precise and rapid assessment of Escherichia coli adherence to vaginal epithelial cells by flow cytometry.

BACKGROUND: In the pathogenesis of Escherichia coli urinary tract infections (UTIs) in women, infecting bacteria adhere to vaginal and periurethral epithelial cells prior to ascending to the bladder and causing infection. Complex interactions among specific bacterial adhesins and various host factors appear to influence adherence of E. coli to mucosal surfaces such as the urogenital epithelium. To conduct population-based studies assessing host epithelial cell determinants that influence bacterial attachment, a method of measuring bacterial adherence utilizing clinically derived epithelial cell samples is needed. METHODS: We developed and standardized an efficient, accurate, high-throughput method for analyzing the adherence of uropathogenic E. coli to clinical samples containing a large number of exfoliated vaginal epithelial cells (VEC). Three wild-type E. coli strains isolated from women with UTI (IA2 expressing pap-encoded, class II fimbriae only; F24 expressing pap-encoded, class II and type 1 fimbriae; and F20, without pap-encoded or type I fimbriae) were transformed with gfpmut3, encoding green fluorescent protein, incubated with VECs, and analyzed by flow cytometry. RESULTS: Enumeration of the binding of each E. coli strain to 10,000 VECs showed reproducible, highly significant strain-dependent differences in adherence to VECs. Differential analysis of the relative contributions of type 1 pili and P fimbrial-mediated binding to the adherence phenotype was performed. It demonstrated that IA2 binding was dependent entirely on P fimbriae, whereas F24 binding was dependent on both P and type 1 fimbriae. CONCLUSIONS: This method has great potential for use in high-throughput analyses of clinically derived epithelial cell samples and will be valuable in population-based investigations of host-parasite interactions in UTI utilizing VECs collected from specific patient groups.