Effect of secretor status on vaginal and rectal colonization with fimbriated Escherichia coli in women with and without recurrent urinary tract infection

Urine Microscopy Score and Neutrophil Lymphocyte Ratio at Presentation are Good Biomarkers of Acute Kidney Injury in Patients with Upper Urinary Tract Infection when Assessed in Correlation with Virulence Factors of Escherichia coli and Blood Group Secretor Status

Acute kidney injury (AKI) is a leading cause of morbidity in urinary tract infection (UTI). We aimed to identify simple biomarkers and bacterial virulence factors associated with AKI in a setting of upper UTI due to uropathogenic Escherichia coli (UPEC). We designed a cross-sectional study to analyse biomarkers of AKI in upper UTI patients. A total of 2758 patients presenting to a tertiary care center with symptoms of upper UTI were assessed for the presence of diabetes mellitus, AKI, blood group non-secretors, urine microscopy and hemogram. 300 patients with UPEC in bacterial culture were studied for bacterial virulence factors by phenotypic and genotypic methods and the patients were followed up for a minimum period of two weeks. Patients with diabetes mellitus, non-secretors, Urine microscopy (UM) score > 2 and higher (> 3.9) neutrophil-lymphocyte ratio (NLR) at initial presentation, were found to be significantly associated with AKI at presentation and predicted AKI at 7th and 14th day follow up. They were also significantly associated with need and increased duration of hospitalization. There was no association of virulence factors of UPEC with diabetes mellitus, AKI or need for hospitalization. However, virulence factors had a significant association (p<0.001)with non-secretors. UM score and NLR are simple tools to identify AKI at presentation and predict AKI during follow-up and the need for hospitalization. Patients with diabetes mellitus and non-secretors are also at higher risk of AKI. Non-secretors are significantly associated with both phenotypic and genotypic expression of virulence factors of UPEC.

Uropathogenic Escherichia coli in the high vaginal swab samples of fertile and infertile women: virulence factors, O-serogroups, and phenotyping and genotyping characterization of antibiotic resistance

Transmission of urinary tract infections into the reproductive system is unavoidable. The present research was performed to assess the distribution of virulence genes, O-serogroups and antibiotic resistance properties of uropathogenic Escherichia coli (UPEC) strains isolated from the high vaginal swab samples of fertile and infertile women. A total of 460 high vaginal swab samples were taken from fertile and infertile women. Distribution of virulence factors and serogroups and antibiotic resistance properties of the E. coli isolates were assessed. Sixty-five out of 460 (14.13%) swab samples were positive for E. coli. Prevalences of E. coli in samples taken from fertile and infertile women were 13.63% and 14.58%, respectively. O1 (7.69%), O2 (6.15%) and O6 (6.15%) were the most frequently detected serogroups. The most frequently detected virulence genes were sfa (72.72%), afa (72.72%), cnf1 (72.72%) and fim (72.72%). The most commonly detected antibiotic-resistance genes were tetA (95.45%), CITM (88.63%), aac(3)-IV (86.36%) and sul1 (72.72%). UPEC strains harboured the highest prevalence of resistance against tetracycline (88.63%), ampicillin (79.54%), gentamicin (77.27%) and enrofloxacin (52.27%). Seventeen out of 26 (65.38%) UPEC strains isolated from infertile women were resistant toward more than ten antibiotic agents. Infertile women with a history of urinary tract infections had the higher prevalence of UPEC strains and also the other characters. High prevalence of the virulent and resistant UPEC strains in the high vaginal part of the infertile women with a history of urinary tract infections may show an important role of these pathogens as causes of female infertility. However, further research is required to confirm this hypothesis.

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.

Drug and Vaccine Development for the Treatment and Prevention of Urinary Tract Infections

Urinary tract infections (UTI) are among the most common bacterial infections in humans, affecting millions of people every year. UTI cause significant morbidity in women throughout their lifespan, in infant boys, in older men, in individuals with underlying urinary tract abnormalities, and in those that require long-term urethral catheterization, such as patients with spinal cord injuries or incapacitated individuals living in nursing homes. Serious sequelae include frequent recurrences, pyelonephritis with sepsis, renal damage in young children, pre-term birth, and complications of frequent antimicrobial use including high-level antibiotic resistance and Clostridium difficile colitis. Uropathogenic E. coli (UPEC) cause the vast majority of UTI, but less common pathogens such as Enterococcus faecalis and other enterococci frequently take advantage of an abnormal or catheterized urinary tract to cause opportunistic infections. While antibiotic therapy has historically been very successful in controlling UTI, the high rate of recurrence remains a major problem, and many individuals suffer from chronically recurring UTI, requiring long-term prophylactic antibiotic regimens to prevent recurrent UTI. Furthermore, the global emergence of multi-drug resistant UPEC in the past ten years spotlights the need for alternative therapeutic and preventative strategies to combat UTI, including anti-infective drug therapies and vaccines. In this chapter, we review recent advances in the field of UTI pathogenesis, with an emphasis on the identification of promising drug and vaccine targets. We then discuss the development of new UTI drugs and vaccines, highlighting the challenges these approaches face and the need for a greater understanding of urinary tract mucosal immunity.

Molecular Epidemiology of Extraintestinal Pathogenic Escherichia coli

Extraintestinal pathogenic Escherichia coli (ExPEC), the specialized E. coli strains that possess the ability to overcome or subvert host defenses and cause extraintestinal disease, are important pathogens in humans and certain animals. Molecular epidemiological analysis has led to an appreciation of ExPEC as being distinct from other E. coli (including intestinal pathogenic and commensal variants) and has offered insights into the ecology, evolution, reservoirs, transmission pathways, host-pathogen interactions, and pathogenetic mechanisms of ExPEC. Molecular epidemiological analysis also provides an essential complement to experimental assessment of virulence mechanisms. This chapter first reviews the basic conceptual and methodological underpinnings of the molecular epidemiological approach and then summarizes the main aspects of ExPEC that have been investigated using this approach.

Obesity and iron deficiency anemia as risk factors for asymptomatic bacteriuria

BACKGROUND

Few studies examined the risk factors of asymptomatic bacteriuria, showing contradictory results. Our study aimed to examine the association between different clinical and laboratory parameters and asymptomatic bacteriuria in internal medicine patients.

MATERIALS AND METHODS

330 consecutive hospitalized subjects, asymptomatic for urinary tract infections (UTIs), underwent to microscopic examination of urine specimens. 100 subjects were positive for microscopic bacteriuria and were recruited into the study. At the quantitative urine culture 31 subjects of study population were positive while 69 subjects were negative for bacteriuria.

RESULTS

The analysis of clinical characteristics showed that the two groups of subjects (positive and negative urine culture for bacteriuria) were significant different (p<0.05) about obesity (76.7% vs 42% respectively), metabolic syndrome (80.6% vs 44,9%), cholelithiasis (35.5% vs 13,2%) and iron deficiency anemia (80.6% vs 53,6%). The univariate analysis showed that only obesity, cholelithiasis and iron deficiency anemia were positively associated with positive urine culture for bacteriuria (Odds Ratios [OR]=3.79, p=0.0003; OR=2,65, p=0.0091; OR=2.63, p=0.0097; respectively). However, the multivariate analysis by logistic regression showed that only obesity and iron deficiency anemia, independently associated with positive urine culture for bacteriuria (OR=3.9695, p=0.0075; OR=3.1569, p=0.03420 respectively).

CONCLUSIONS

This study shows that obesity and iron deficiency anemia are independent risk factors for asymptomatic bacteriuria.

Urinary tract infections in older women: a clinical review

IMPORTANCE

Asymptomatic bacteriuria and symptomatic urinary tract infections (UTIs) in older women are commonly encountered in outpatient practice.

OBJECTIVE

To review management of asymptomatic bacteriuria and symptomatic UTI and review prevention of recurrent UTIs in older community-dwelling women.

EVIDENCE REVIEW

A search of Ovid (Medline, PsycINFO, Embase) for English-language human studies conducted among adults aged 65 years and older and published in peer-reviewed journals from 1946 to November 20, 2013.

RESULTS

The clinical spectrum of UTIs ranges from asymptomatic bacteriuria, to symptomatic and recurrent UTIs, to sepsis associated with UTI requiring hospitalization. Recent evidence helps differentiate asymptomatic bacteriuria from symptomatic UTI. Asymptomatic bacteriuria is transient in older women, often resolves without any treatment, and is not associated with morbidity or mortality. The diagnosis of symptomatic UTI is made when a patient has both clinical features and laboratory evidence of a urinary infection. Absent other causes, patients presenting with any 2 of the following meet the clinical diagnostic criteria for symptomatic UTI: fever, worsened urinary urgency or frequency, acute dysuria, suprapubic tenderness, or costovertebral angle pain or tenderness. A positive urine culture (≥105 CFU/mL) with no more than 2 uropathogens and pyuria confirms the diagnosis of UTI. Risk factors for recurrent symptomatic UTI include diabetes, functional disability, recent sexual intercourse, prior history of urogynecologic surgery, urinary retention, and urinary incontinence. Testing for UTI is easily performed in the clinic using dipstick tests. When there is a low pretest probability of UTI, a negative dipstick result for leukocyte esterase and nitrites excludes infection. Antibiotics are selected by identifying the uropathogen, knowing local resistance rates, and considering adverse effect profiles. Chronic suppressive antibiotics for 6 to 12 months and vaginal estrogen therapy effectively reduce symptomatic UTI episodes and should be considered in patients with recurrent UTIs.

CONCLUSIONS AND RELEVANCE

Establishing a diagnosis of symptomatic UTI in older women requires careful clinical evaluation with possible laboratory assessment using urinalysis and urine culture. Asymptomatic bacteriuria should be differentiated from symptomatic UTI. Asymptomatic bacteriuria in older women should not be treated.

Hepatitis A virus: serology and molecular diagnostics

The diagnosis of hepatitis A virus (HAV) infection is based on the detection of anti-HAV IgM. Shortcomings of this serological approach include the persistence of IgM after normalization of liver enzymes or its detection during polyclonal activation of the immune system due to unrelated viral infection or autoimmune diseases. Molecular diagnosis of HAV along with anti-HAV IgG avidity measurement are helpful in case of positive IgM where laboratory evidence of acute hepatitis is absent and there is no epidemiologic link to other cases. Molecular epidemiology allows us to determine whether viruses from different locations are related to each other and provides further understanding of viral epidemiology by identifying sources and transmission modes. It has been demonstrated that the rapid turnover of HAV strains in low-endemicity countries is caused by their introduction by travelers. Growing sequence databases allow for the identification of geographic origin of viral strains. Collaboration between surveillance laboratories, including database sharing, should be promoted for deeper investigation of outbreaks and improved prevention approaches.

Infection-associated FUT2 (Fucosyltransferase 2) genetic variation and impact on functionality assessed by in vivo studies

The secretor (Se)/nonsecretor (se) histo-blood group variation depends on the action of the FUT2 enzyme and has major implications for human susceptibility to infections. To characterize the functionality of FUT2 variants, we assessed the correlation between saliva phenotypes and sequence variation at the FUT2 gene in sixty seven individuals from northern Portugal. While most non-secretor haplotypes were found to carry the 428G > A nonsense mutation in association with a 739G > A missense substitution, we have also identified a recombinant haplotype carrying the 739*A allele together with the efficient 428*G variant in individuals with the Se phenotype. This finding suggested, in contrast to previous results, that the 739*A allele encodes an efficient Se allele. To test this hypothesis we evaluated the in vivo enzyme activity of full coding expression constructs in transient transfection of CHO-K1 cells using FACS (fluorescence-activated cell sorting) analysis and expression of type 2 and type 3 chain H structures as read out. We detected FUT2 activity for the 739*A expression construct, demonstrating that the 739G > A substitution is indeed not inactivating. In accordance with the hypothesis that FUT2 is under long standing balancing selection, we estimated that the time depth of FUT2 global genetic variation is as old as 3 million years. Age estimates of specific variants suggest that the 428G > A mutation occurred at least 1.87 million years ago while the 739G > A substitution is about 816,000 years old. The 385A > T missense mutation underlying the non-secretor phenotype in East Asians appears to be more recent and is likely to have occurred about 256,000 years ago.

Widespread gene conversion of alpha-2-fucosyltransferase genes in mammals

The alpha-2-fucosyltransferases (alpha2FTs) are enzymes involved in the biosynthesis of alpha2fucosylated glycan structures. In mammalian genomes, there are three alpha2FT genes located in tandem-FUT1, FUT2, and Sec1-each contained within a single exon. It has been suggested that these genes originated from two successive duplications, with FUT1 being generated first and FUT2 and Sec1 second. Despite gene conversion being considered the main mechanism of concerted evolution in gene families, previous studies of primates alpha2FTs failed to detect it, although the occurrence of gene conversion between FUT2 and Sec1 was recently reported in a human allele. The primary aim of our work was to initiate a broader study on the molecular evolution of mammalian alpha2FTs. Sequence comparison leads us to confirm that the three genes appeared by two rounds of duplication. In addition, we were able to detect multiple gene-conversion events at the base of primates and within several nonprimate species involving FUT2 and Sec1. Gene conversion involving FUT1 and either FUT2 or Sec1 was also detected in rabbit. The extent of gene conversion between the alpha2FTs genes appears to be species-specific, possibly related to functional differentiation of these genes. With the exception of rabbits, gene conversion was not observed in the region coding the C-terminal part of the catalytic domain. In this region, the number of amino acids that are identical between FUT1 and FUT2, but different in Sec1, is higher than in other parts of the protein. The biologic meaning of this observation may be related to functional constraints.

Relationship between Escherichia coli strains causing acute cystitis in women and the fecal E. coli population of the host

Previous epidemiological assessments of the prevalence versus special-pathogenicity hypothesis for urinary tract infection (UTI) pathogenesis in women may have been confounded by underlying host population differences between women with UTI and healthy controls and have not considered the clonal complexity of the fecal Escherichia coli population of the host. In the present study, 42 women with acute uncomplicated cystitis served as their own controls for an analysis of the causative E. coli strain and the concurrent intestinal E. coli population. Clonality among the urine isolate and 30 fecal colonies per subject was assessed by repetitive-element PCR and macrorestriction analysis. Each unique clone underwent PCR-based phylotyping and virulence genotyping. Molecular analysis resolved 109 unique clones (4 urine-only, 38 urine-fecal, and 67 fecal-only clones). Urine clones exhibited a significantly higher prevalence of group B2 than fecal-only clones (69% versus 10%; P < 0.001) and higher aggregate virulence scores (mean, 6.2 versus 2.9; P < 0.001). In multilevel regression models for predicting urine clone status, significant positive predictors included group B2, 10 individual virulence traits, the aggregate virulence score, fecal dominance, relative fecal abundance, and (unique to the present study) a pauciclonal fecal sample. In summary, within the fecal E. coli populations of women with acute cystitis, pauciclonality, clonal dominance, virulence, and group B2 status are closely intertwined. Phylogenetic group B2 status and/or associated virulence factors may promote fecal abundance and pauciclonality, thereby contributing to upstream steps in UTI pathogenesis. This relationship suggests a possible reconciliation of the prevalence and special-pathogenicity hypotheses.

Do panty liners promote vulvovaginal candidiasis or urinary tract infections? A review of the scientific evidence

Panty liners are used to absorb light menstrual flow, vaginal discharge, or urine leakage, or to maintain a clean, dry feeling. Allegations that panty liners may trap heat and moisture to promote vulvovaginal candidiasis (VVC) or promote colonization by microbes that contribute to urinary tract infections appear to be unfounded. As reviewed herein, measurements of the impact of panty liners on skin temperature and skin surface moisture had no clinically meaningful effect on cell densities of genital microflora. Epidemiological investigations of a potential link to VVC were either negative or were inconclusive because of confounding factors. Although enteric microbes reside on the vulva and perineum, no evidence exists that panty liner use promotes urethral colonization by enteric microbes. Moreover, a series of 13 randomized prospective trials of panty liners or ultra-thin pads demonstrated no clinically significant adverse effects either on the skin or on isolation frequencies or cell densities of representative genital microflora. Post-market surveillance systems suggest a low incidence of complaints. Evidence from vulvar clinic patients reveals no significant contribution of these products to persistent vulvar symptoms. Taken together, the scientific evidence supports the conclusion that panty liners are safe when used as intended and do not promote VVC or urinary tract infections.

Adherence of Lactobacillus crispatus to vaginal epithelial cells from women with or without a history of recurrent urinary tract infection

PURPOSE

Lactobacillus crispatus strain CTV-05 is a vaginal probiotic proposed for use in women with recurrent urinary tract infection to reduce vaginal colonization with Escherichia coli and the risk of urinary tract infection. However, the ability of this probiotic strain to adhere to the target mucosa, vaginal epithelial cells, has not been assessed in women with recurrent urinary tract infection. We measured the adherence of L. crispatus strain CTV-05 to vaginal epithelial cells collected from more than 100 premenopausal women with (cases) and without (controls) a history of recurrent urinary tract infection. We also examined the effects of relevant host factors on bacterial adherence.

MATERIALS AND METHODS

Bacterial adherence assays were performed by combining L. crispatus CTV-05 with exfoliated vaginal epithelial cells collected from 51 case women and 51 controls.

RESULTS

L. crispatus CTV-05 adhered in high numbers to vaginal epithelial cells from women with recurrent urinary tract infection (mean adherence of 50.5 lactobacilli per vaginal epithelial cell) and controls (mean adherence of 39.4 lactobacilli per vaginal epithelial cell). Adherence was significantly higher using vaginal epithelial cells from women with a maternal history of urinary tract infection (p = 0.036) and a nonsecretor phenotype (p < 0.001), but was not significantly affected by recent spermicide use, oral contraceptive use, menstrual cycle phase or sexual activity.

CONCLUSIONS

L. crispatus strain CTV-05 is highly adherent to vaginal epithelial cells collected from a large sample of premenopausal women with or without a history of recent recurrent urinary tract infection. These data strongly support further evaluation of this probiotic in clinical trials of women with recurrent urinary tract infection.

Mendelian resistance to human norovirus infections

Noroviruses have emerged as a major cause of acute gastroenteritis in humans of all ages. Despite high infectivity of the virus and lack of long-term immunity, volunteer and authentic studies has suggested the existence of inherited protective factors. Recent studies have shown that histo-blood group antigens (HBGAs) and in particular secretor status controlled by the α1,2fucosyltransferase FUT2 gene determine susceptibility to norovirus infections, with nonsecretors (FUT2−/−), representing 20% of Europeans, being highly resistant to symptomatic infections with major strains of norovirus. Moreover, the capsid protein from distinct strains shows different HBGA specificities, suggesting a host–pathogen co-evolution driven by carbohydrate–protein interactions.

Relationship between Escherichia coli strains causing urinary tract infection in women and the dominant faecal flora of the same hosts

To clarify whether prevalence or special pathogenicity is more important in determining urinary tract infection (UTI) causation, we compared the biotype, phylogenetic group, and virulence genes of Escherichia coli urine strains from 11 women with acute lower UTI with those of the host's dominant intestinal E. coli strain(s). Twenty-one unique E. coli clones were identified. For three women, the single faecal clone identified was also the host's urine clone, whereas for eight women faecal samples yielded 1 or 2 distinct non-urine clones (total, n = 10), either with (n = 3) or without (n = 5) the concurrent urine clone. The eight urine clones from the latter eight women exhibited significantly greater inferred virulence, according to virulence gene content and phylogenetic background, than did the hosts' 10 corresponding 'faecal only' clones. In contrast, the three urine clones that were detected as the host's sole faecal clone exhibited significantly lower inferred virulence than the other eight urine clones, and were statistically indistinguishable from the 10 'faecal only' clones. In conclusion, special pathogenicity is an important determinant of UTI pathogenesis in women, although prevalence may occasionally allow less virulent strains to cause UTI.

Molecular epidemiology of extraintestinal pathogenic (uropathogenic) Escherichia coli

Molecular epidemiological analyses of extraintestinal pathogenic Escherichia coli (ExPEC), which are also called "uropathogenic E. coli" since they are the principle pathogens in urinary tract infection, involve structured observations of E. coli as they occur in the wild. Careful selection of subjects and use of appropriate methods for genotyping and statistical analysis are required for optimal results. Molecular epidemiological studies have helped to clarify the host-pathogen relationships, phylogenetic background, reservoirs, and transmission pathways of ExPEC, to assess potential vaccine candidates, and to delineate areas for further study. Ongoing discovery of new putative virulence factors (VFs), increasing awareness of the importance of VF expression and molecular variants of VFs, and growing appreciation of transmission as an important contributor to ExPEC infections provide abundant stimulus for future molecular epidemiological studies. Published by Elsevier GmbH.

Recurrent urinary tract infections

Urinary tract infection (UTI) is one of the most common bacterial infections in women, and one in four of these women will develop a recurrence. Various risk factors predispose women of different age groups to recurrence. These factors include sexual intercourse, use of contraception, antimicrobials, oestrogen, genetics, and the distance of the urethra from the anus. Of the different pathogens, Escherichia coli is the organism most commonly isolated. A variety of treatment options has been proposed, including long-term or post-intercourse prophylaxis and patient-initiated therapy. Oestrogen and cranberry juice have also been used as prophylactic treatment adjuncts. At present, other therapeutic and preventive modalities are being investigated, including the development of vaccines to treat those most severely affected.

Pathogenesis of urinary tract infections with normal female anatomy

Recurrent urinary tract infections (UTIs) are common among girls and young women who are healthy and have anatomically normal urinary tracts. These infections are a main source of morbidity and health-care costs in this population. The interaction between specific infecting bacteria and urinary tract epithelium characteristics underlies the pathogenesis of this disease. Several pathogen-related factors predispose people to recurrent UTI, including periurethral bacterial colonisation and Escherichia coli virulence. Host behavioural risk factors include voiding dysfunction, high intercourse frequency, and oral contraceptive and spermicide use. The role of vesicoureteral reflux in recurrent childhood UTI is probably overestimated in the medical literature and is important only in a small group of children with high-grade reflux. Family pedigree analysis suggests a familial genetic predisposition for UTI among young females. Animal models show the multigenic nature of recurrent UTI. Putative candidate genes for the disease include ABH blood groups, interleukin-8 receptor (CXCR1), the human leucocyte antigen locus, toll-like receptors, tumour necrosis factor, and Tamm-Horsfall protein.

LacZ expression in Fut2-LacZ reporter mice reveals estrogen-regulated endocervical glandular expression during estrous cycle, hormone replacement, and pregnancy

The secretor gene (FUT2) encodes an alpha(1,2)fucosyltransferase (E.C. 2.4.1.69) that elaborates alpha(1,2)fucose residues on mucosal epithelium and secreted mucins. Though uterine alpha(1,2)fucosylated glycans have been proposed to be involved in embryo adhesion, mice with a homozygous null mutation of Fut2 displayed normal fertility. To help develop alternative hypotheses for function, the cell type and regulation of Fut2 expression during the estrous cycle, hormone replacement, and pregnancy was examined in Fut2-LacZ reporter mice containing targeted replacement of Fut2 with bacterial lacZ. LacZ expression in the reproductive tract of Fut2-LacZ mice is most prominent in the glandular epithelium of the endocervix during estrus and pregnancy. Nuclear LacZ expression identifies cell-specific expression of Fut2 in mucus-secreting cells of the endocervix, uterine glands, foveolar pit and chief cells of the stomach, and goblet cells of the colon. In ovariectomized Fut2-LacZ mice, estradiol treatment stimulates X-gal staining in endocervix and uterus but does not affect expression in stomach and colon. Northern blot analysis in wild-type mice shows 15-fold elevations of Fut2 steady-state mRNA with estradiol treatment, whereas Fut1 varies little. Fut2 levels in the glandular stomach and distal colon remain constant, and uterine Fut2 levels vary eightfold during the estrous cycle. These data represent the first demonstration of a glycosyltransferase gene under tissue-specific hormonal regulation in a LacZ reporter mouse model. Endocervical expression of Fut2 in estrus and pregnancy may modify cervical mucus barrier properties from microbial infection analogous to the potential role of mucosal glycans in humans.

Histologic Endometritis in Asymptomatic Human Immunodeficiency Virus–Infected Women

OBJECTIVE

To estimate the prevalence, risk factors, clinical symptoms and signs, and response to antimicrobial therapy of histologic endometritis in human immunodeficiency virus (HIV)-infected women without clinical salpingitis.

METHODS

This was a cross-sectional study of 42 HIV-infected women enrolled from a single clinic. Subjects underwent standardized history, examination, and laboratory determinations, including endometrial biopsy. Women with suspected pelvic inflammatory disease were excluded. All women were given antibiotics and repeat evaluation in 5-7 weeks. Histologic endometritis was defined by at least one stromal plasma cell per 120x field and five or more surface polymorphonuclear leukocytes per 400x field. Chi-square and Fisher exact tests were used as appropriate.

RESULTS

Histologic endometritis was present among 16 (38%) of 42 evaluable HIV-infected women, none of whom had Chlamydia trachomatis or Neisseria gonorrhoeae. Douching three or more times per month, history of ectopic pregnancy, and two or more prior urinary tract infections were associated with endometritis, as was elevated erythrocyte sedimentation rate (P < or = .05). Physical examination findings and mean CD4+ lymphocyte count were similar among those with and without endometritis. In the nine HIV-infected women with a repeat biopsy, endometritis decreased from four (44%) to two (22%) after treatment (P = .30).

CONCLUSION

The prevalence of histologic endometritis in HIV-infected women was high despite few examination findings and no demonstrated pathogens. Endometritis in HIV-infected women might be related to pathogens not evaluated, to prior infection, or to reduced immunity from HIV.

Epidemiology of urinary tract infections: transmission and risk factors, incidence, and costs

Uropathogenic E. coli have special features that allow them to take advantage of the bladder environment. There UPEC can grow to substantial numbers in pure culture that are shed frequently into the environment and have a high probability of transmission to other hosts. A better understanding of the transmission system and the host and bacterial factors influencing transmission is essential for the identification of effective prevention strategies. Although the risk of severe morbidity among otherwise healthy populations is low, the incidence is high. Further, the potential impact of antibiotic treatment on the emergence of increasingly antibiotic-resistant UPEC (the resistant mechanisms that may be transmitted to other bowel inhabitants) is high. The benefits of successfully preventing UTI are substantial.

Effect of trimethoprim-sulfamethoxazole on recurrent bacteriuria and bacterial persistence in mice infected with uropathogenic Escherichia coli

One of the more perplexing aspects of urinary tract infections (UTIs) is their high propensity to recur. It has been proposed that recurrent infections are a result of the reintroduction of bacteria from the gastrointestinal tract (GIT) to the urinary tract (UT); however, since a significant subset of recurrent UTIs are caused by an identical bacterial strain, it has been challenging to formally prove this hypothesis for same-strain recurrences by using epidemiologic approaches. We present data here obtained by using a mouse model of UTIs in which it was shown that 36% (5 of 14) of mice infected with uropathogenic Escherichia coli (UPEC) will have at least one bacteriuric recurrence, with 21% (3 of 14) having more than one recurrence during a 6-week period after an acute UTI. Intraurethrally infected mice develop UPEC reservoirs in both their feces and their bladders. Ten days of trimethoprim-sulfamethoxazole (SXT) therapy reduces urinary recurrences and eradicates fecal colonization, whereas 3 days of SXT treatment has no effect over a twenty-eight-day observation period despite clearing fecal colonization acutely. Interestingly, SXT is unable to eradicate bacteria from the bladder reservoir even after a 10-day treatment regimen, thus demonstrating that the bladder reservoir can persist even in the face of long-term antibiotic therapy.

Non-secretor status is associated with female acute uncomplicated pyelonephritis

OBJECTIVE

To retrospectively analyse the secretor status in women with acute uncomplicated pyelonephritis, as non-secretors of histo-blood group antigens are reportedly at risk of recurrent urinary tract infections (UTIs).

PATIENTS AND METHODS

The study included 245 women who had been diagnosed as having acute uncomplicated pyelonephritis in affiliated hospitals over the past 5 years. All women were sent antiseptic swabs, to collect saliva, and a questionnaire to survey their past UTI episodes and menstrual status. Responses with written informed consent were obtained from 106 women (median age 50.5 years, range 17-85). The secretor status was determined using the haemagglutination inhibition assay from the saliva on the swabs.

RESULTS

Forty-four (41%) of the women were non-secretors, a significantly higher frequency than in the (control) Japanese population (217 of 960, 22.6%; P< 0.001). The incidence of non-secretors was significantly higher (P < 0.01) in premenopausal (26 of 46, 57%) than in postmenopausal women (18 of 60, 30%).

CONCLUSION

These results suggest that non-secretor status is associated with a genetic susceptibility to acute uncomplicated pyelonephritis, especially in premenopausal women.

Recent advances into the pathogenesis of recurrent urinary tract infections: the bladder as a reservoir for uropathogenic Escherichia coli

Recurrent cystitis is a common clinical entity that is becoming increasingly challenging to manage. The current thought regarding the pathogenesis of these infections is evolving as new data emerges to suggest that some recurrences may originate from previously unrecognized reservoirs of uropathogenic Escherichia coli. This article will summarize recent conceptual changes with respect to the aetiology of recurrent urinary tract infections, particularly as it relates to chronic bacterial persistence in the bladder.

Relatedness of Escherichia coli colonizing women longitudinally

PURPOSE

The longitudinal colonization patterns by Escherichia coli of the vaginal introitus and urinary tract were investigated.

MATERIALS AND METHODS

Cultures of the vaginal introitus and midstream urine were collected once a week for 12 consecutive weeks from five women with (patients) and five without (controls) a history of urinary tract infection (UTI).

RESULTS

A total of 63 E. coli isolates was obtained from the 10 women, 26 from controls and 37 from patients. The bacterial counts of E. coli present in control individuals were uniformly low, < or = 200 E. coli/mL. The numbers in patients were higher and more variable, reaching > 10(5)/mL in urine and vaginal specimens. In 16 instances, E. coli was present in the urine and the vaginal introitus concurrently (matched isolates). Random amplified polymorphic DNA (RAPD) fingerprinting was used to characterize all matched E. coli isolates. Concurrent vaginal and urinary tract colonization was more common in the patient population, and usually, the same E. coli strain was present at both sites; only 15% of the matched isolates represented different strains. The RAPD fingerprinting was also carried out on selected isolates recovered from four patients and three control individuals over the 12-week study period. Colonization of the vaginal introitus and urinary tract in these individuals varied over time. Generally, however, a predominant E. coli strain was present in the vaginal milieu, urinary tract, or both, either continuously (for as long as 9 consecutive weeks in one patient) or intermittently.

CONCLUSION

The results support the concept that the vaginal mucosa acts as reservoir of E. coli which may enter the urinary tract.

X Chromosomal short tandem repeat polymorphisms near the phosphoglycerate kinase gene in men with chronic prostatitis

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) causes substantial morbidity afflicting approximately 10% of adult males. Treatment is often empirical and ineffective since the etiology is unknown. Other prostate and genitourinary diseases have genetic components suggesting that CP/CPPS may also be influenced by genetic predisposition. We recently reported a highly polymorphic short tandem repeat (STR) locus near the phosphoglycerate kinase gene within Xq11-13. Because this STR is in a region known to predispose towards other prostate diseases, we compared STR polymorphisms in 120 CP/CPPS patients and 300 control blood donors. Nine distinct allele sizes were detected, ranging from 8 to 15 repeats of the tetrameric STR plus a mutant allele (9.5) with a six base deletion in the flanking DNA sequence. The overall allele size distribution in the CP/CPPS patients differed from controls (Chi-square=19.252, df=8, P=0.0231). Frequencies of two specific alleles, 9.5 and 15, differed significantly in CP/CPPS vs. control subjects and allele 10 differed with marginal significance. Alleles 9.5 and 10 were both more common in CP/CPPS patients than controls while allele 15 was less common. These observations suggest that Xq11-13 may contain one or more genetic loci that predispose toward CP/CPPS. Further investigations involving family studies, larger patient populations, and other control groups may help elucidate this potential genetic predisposition in CP/CPPS.

Virulence factors of Escherichia coli isolated from female reproductive tract infections and neonatal sepsis

OBJECTIVE

The presence of enterobacteria such as Escherichia coli in the vagina of normal women is not synonymous with infection. However, vaginal E. coli may also cause symptomatic infections. We examined bacterial virulence properties that may promote symptomatic female reproductive tract infections (RTI) and neonatal sepsis.

METHODS

E. coli isolated as the causative agent from cases of vaginitis (n = 50), tubo-ovarian abscess (n = 45) and neonatal sepsis (n = 45) was examined for selected phenotypic and genetic virulence properties. Results were compared with the frequency of the same properties among fecal E. coli not associated with disease.

RESULTS

A significantly greater proportion of infection E. coli exhibited D-mannose resistant hemagglutination compared with fecal E. coli (p < 0.01). This adherence phenotype was associated with the presence of P fimbriae (pap) genes which were also significantly more prevalent among isolates from all three infection sites (p < 0.01). The majority of pap+ isolates contained the papG3 allele (Class II) regardless of infection type. Increased frequency of Type IC genes among vaginitis and abscess isolates was also noted. No significant differences in frequency of other bacterial adherence genes, fim, sfa, uca (gaf or dra were observed. E. coli associated with vaginitis was significantly more likely to be hemolytic (Hly+) than were fecal isolates (p < 0.05). The Hly+ phenotype was also more prevalent among tubo-ovarian abscess and neonatal sepsis isolates (p < 0.08).

CONCLUSIONS

E. coli isolated from female RTI and neonatal sepses possess unique properties that may enhance their virulence. These properties are similar to those associated with other E. coli extra-intestinal infections, indicating that strategies such as vaccination or bacterial interference that may be developed against urinary tract infections (UTI) and other E. coli extra-intestinal infections may also prevent selected female RTI.

Prevalence of antibody to hepatitis A virus in drinking water workers and wastewater workers in Texas from 1996 to 1997

To determine if wastewater workers had a higher prevalence of antibody to hepatitis A virus (anti-HAV) than drinking water workers, a convenience sample of Texas wastewater and drinking water workers was evaluated for risk factors by questionnaire and tested for anti-HAV. A total of 359 wastewater and 89 drinking water workers participated. Anti-HAV positivity was 28.4% for wastewater and 23.6% for drinking water workers. After adjustment for age, educational attainment, and Hispanic ethnicity, the odds ratio for the association between anti-HAV positivity and wastewater industry employment was 2.0 (95% confidence interval, 1.0 to 3.8). Among wastewater workers, never eating in a lunchroom, > or = 8 years in the wastewater industry, never wearing face protection, and skin contact with sewage at least once per day were all significantly associated with anti-HAV positivity in a model that adjusted for age and educational attainment. Wastewater workers in this study had a higher prevalence of anti-HAV than drinking water workers, which suggested that wastewater workers may have been at increased risk of occupationally acquired hepatitis A. Work practices that expose workers to wastewater may increase their risk.

Urinary Tract Infection in Postmenopausal Women

Urinary tract infection (UTI) is common in postmenopausal women; the estimated incidence ranges from 4% to 15%. The clinical presentation of UTI is somewhat different in postmenopausal older women than it is in younger women: postmenopausal women are less likely to report frequency, dysuria, hematuria, and fever, but are more likely to report flank pain. Other than UTI history, risk factors for symptomatic UTI among postmenopausal women are poorly described. Hormonal replacement therapy minimizes physiologic changes associated with menopause that lead to genitourinary symptoms and, potentially, to UTI, but whether this therapy is appropriate for the prevention of recurrent UTI in postmenopausal women is uncertain.

Evaluation of and antimicrobial therapy for recurrent urinary tract infections in women

The problem with recurrent urinary tract infections in women is enormous and contributes significantly to national health care costs. As the role of office urology and the external "cost-effective" pressures placed on the practicing urologist have heightened, a consistent, logical approach towards diagnosis and management of urinary tract infection becomes essential. This article briefly discusses the cause and pathophysiology behind recurrent urinary tract infections in women. A practical discussion of proper evaluation and treatment options will also be provided in hopes of offering the clinician a simple, stepwise approach to this sometimes difficult condition.

Diversity of hemagglutination phenotypes among P-fimbriated wild-type strains of Escherichia coli in relation to papG allele repertoire

Data regarding the hemagglutination (HA) patterns of the three variants (classes I, II, and III) of the Escherichia coli adhesin PapG are conflicting. These HA patterns usually have been assessed for each papG allele separately with recombinant strains in slide HA assays. We rigorously evaluated an alternative microtiter tray HA assay and then used it to assess the HA of four erythrocyte types (human A1P1 and OP1, rabbit, and sheep erythrocytes) by multiple wild-type E. coli strains representing the four naturally occurring combinations of the papG alleles, i.e., class I plus III, class III only, class II plus III, and class II only. The microtiter tray HA assay displayed significantly better reproducibility of intraobserver (83%) and interobserver (86%) results than did slide HA assays (39 and 73%, respectively). Novel findings from the study of 32 wild-type P-fimbriated strains included reproducible determinations of phenotypic diversity among different papG categories, among strains within each papG category, and from day to day for individual strains. There was also substantial overlap of phenotypes between papG categories I plus III and III only and between II plus III and II only. A class III papG recombinant strain's HA pattern differed significantly from that of the wild-type class III strains. These data demonstrate that HA phenotypes of wild-type P-fimbriated E. coli strains can be reproducibly assessed by a microtiter HA assay and that they correspond broadly to papG genotype but in a more complex and varied fashion than previously recognized.

Virulence characteristics and DNA fingerprints of Escherichia coli isolated from women with acute uncomplicated pyelonephritis

PURPOSE

Previous studies indicated that acute pyelonephritis in infants is initiated by the dominance of uropathogenic strains in fecal flora. Such pathogenic evidence, however, is still lacking for adult women. In this study, the validity of a fecal-perineal-urethral hypothesis in acute uncomplicated pyelonephritis of adult women was assessed at a genetic level.

MATERIALS AND METHODS

A total of 1,200 Escherichia coli isolates from the urine and rectal swab of 12 adult women with acute uncomplicated pyelonephritis were examined. The clonality of the urinary and fecal isolates was evaluated by genotyping of 6 urovirulence determinants and pulsed-field gel electrophoresis. Furthermore, urovirulence genotypes were examined in E. coli isolates from the rectal swab of 30 normal healthy women (mean 26.7 isolates per person).

RESULTS

The E. coli strains causing pyelonephritis were present in the rectal swab in 10 of 12 patients and were a predominant fecal clone in 9 cases. Also, P-fimbriated strains dominated in the fecal flora in 10 of 30 normal healthy women.

CONCLUSIONS

The clonal identity of the urinary and fecal strains in acute pyelonephritis clearly supports the fecal-perineal-urethral hypothesis.