Frequency of antibiotic resistance among group B Streptococcus isolated from healthy college students.

We report resistant rates to erythromycin and clindamycin among Streptococcus agalactiae (group B Streptococcus) isolated from a random sample of healthy male and nonpregnant female college students. Observed resistance rates were twice as high as those reported among pregnant women from the same geographic area 2 years prior.

Urinary tract infection among women aged 40 to 65: behavioral and sexual risk factors.

We conducted a case-control study to explore the role of health behavior and sexual and medical history on urinary tract infection (UTI) risk among otherwise healthy women aged 40-65. Cases and controls were recruited from nine practices and clinics in Michigan and a single clinic in Israel. In both countries, several factors were reported significantly more frequently among UTI cases than controls: a previous UTI within 12 months, incontinence symptoms, a recent episode of 30-plus minutes of cold hands, feet, back or buttocks, and recent antibiotic use. Cases were less likely than controls to report recent estrogen use, but the results were only statistically significant in Michigan. Sexual activity during the previous 2 weeks and having ceased menses were modestly, but not statistically significantly, protective at both study sites. Risk factors for UTI among women 40-65 differ from those for younger women and these differences cannot be attributed solely to changes in menopausal status.

Prevalence of known P-fimbrial G alleles in Escherichia coli and identification of a new adhesin class.

Screening a large Escherichia coli collection for P-fimbrial adhesin classes identified 20 unclassifiable strains. Cloning and sequencing of papG from an unclassifiable strain identified another G allele. The novel adhesin gene has 65% identity to the class I adhesin gene, 44% identity to the class II adhesin gene, and 43% identity to the class III adhesin gene.

Prevalence and co-colonization with group b streptococcus (Gbs) Among heterosexual college couples.

PURPOSE: Maternal colonization with GBS is a major cause of neonatal sepsis and meningitis. While GBS transmission is assumed to be fecal-oral or person-to-person direct contact including possible sexual transmission, risk factors for colonization and carriage are poorly described. Basic descriptive epidemiologic information is needed in order to implement a prevention program such as the development of an effective vaccine.METHODS: As part of a study of heterosexual transmission of urinary tract infection (UTI), we describe the prevalence and co-colonization of GBS among college couples. Self-collected vaginal, urine and rectal specimens were cultured from women with UTI and their current sex partners ("case couples"), and from women without UTI and their current sex partners ("control couples").RESULTS: Thirty-four percent (98/285) of case women and 31% (56/182) of control women had at least one GBS isolate. 25% (45/177) of case men and 26% (32/122) of control men had at least one GBS isolate. Given that GBS was present in one partner, 45% of case (34/75) and 57% of control (24/42) couples were co-colonized. Using pulsed-field gel electrophoresis (PFGE) analysis, GBS isolates shared within couples were identical in most cases, but PFGE patterns differed across couples.CONCLUSIONS: Prevalence of GBS is high among sexually active college students and sexual contact is associated with increased transmission.

Risk factors for second urinary tract infection among college women.

To better understand the etiology of recurrent urinary tract infection (UTI), the authors followed a cohort of 285 female college students with first UTI for 6 months or until second UTI. A first UTI due to Escherichia coli was followed by a second UTI three times more often than was a non-E. coli first UTI (24 vs. 8%; p = 0.02). In a logistic regression analysis limited to the 224 women from the University of Michigan Health Service and the University of Texas at Austin Health Service from September 1992 to December 1994, with a first UTI due to E. coli, vaginal intercourse increased the risk of a second UTI with both a different (odds ratio (OR) = 1.60, 95% confidence interval (CI): 1.19, 2.15) and the same (OR = 1.37, 95% CI: 0.91, 2.07) uropathogen, as did using a diaphragm, cervical cap, and/or spermicide (same uropathogen: OR = 1.53, 95% CI: 0.95, 2.47; different uropathogen: OR = 1.77, 95% CI: 1.22, 2.58). Condom use decreased the risk of a second UTI caused by a different uropathogen (OR = 0.68, 95% CI: 0.48, 0.99) but had no effect on a second UTI caused by the same E. coli (OR = 0.99; 95% CI: 0.66, 1.50). Type or duration of treatment was not associated with a second UTI. Although the risk of second UTI is strongly influenced by sexual behavior, women with a first UTI caused by E. coli are more likely than are those with a non-E. coli first UTI to have a second UTI within 6 months.

Molecular epidemiologic approaches to urinary tract infection gene discovery in uropathogenic Escherichia coli.

Urinary tract infection (UTI) is one of the most frequently acquired bacterial infections. The vast majority of UTIs are caused by a large, genetically heterogeneous group of Escherichia coli. This genetic diversity has hampered identification of UTI-related genes. A three-step experimental strategy was used to identify genes potentially involved in E. coli UTI transmission or virulence: epidemiologic pairing of a UTI-specific strain with a fecal control, differential cloning to isolated UTI strain-specific DNA, and epidemiologic screening to identify sequences among isolated DNAs that are associated with UTI. The 37 DNA sequences initially isolated were physically located all over the tester strain genome. Only two hybridized to the total DNA of the sequenced E. coli K-12 strain; eight sequences were present significantly more frequently in UTI isolates than in fecal isolates. Three of the eight sequences matched to genes for multidrug efflux proteins, usher proteins, and pathogenicity island insertion sites, respectively. Using population characteristics to direct gene discovery and evaluation is a productive strategy applicable to any system.

Initial rate of healing predicts complete healing of venous ulcers.

BACKGROUND: Venous ulcers represent a clinical problem with considerable morbidity, especially in the elderly population. Standard treatment is the use of leg compression bandages to improve the underlying venous hypertension, but not every ulcer heals in a timely fashion with this treatment modality. Methods are needed to predict the outcome of standard treatment as soon as possible to institute alternative therapy. OBJECTIVE: To prospectively study the rate of healing in a group of elderly patients with venous ulcers, based on a previously described equation that takes into account the size and perimeter of the ulcer. METHODS: We studied by computerized planimetry 15 elderly patients with venous ulcers treated with leg compression bandages for up to 24 weeks or until complete healing. We determined weekly healing rate by comparing ulcer size at each visit to initial baseline size (baseline-adjusted healing rate). Also, we used a novel way to calculate the healing rate at a given week by taking the mean of all previous healing rates between each visit (mean-adjusted healing rate). RESULTS: When using the baseline-adjusted healing rate, we noted what we describe as a healing rate instability from week to week, which decreases the ability to predict complete healing. However, the mean-adjusted healing rate allowed us to predict complete healing as early as 3 weeks from starting therapy (P<.001). CONCLUSION: In this prospective study of elderly patients with venous ulcers, we describe a novel and more powerful method for predicting complete healing of venous ulcers with compression therapy alone.

Distribution of drb genes coding for Dr binding adhesins among uropathogenic and fecal Escherichia coli isolates and identification of new subtypes.

The Dr family of related adherence structures, some fimbriated and others afimbriated, bind to decay-accelerating factor molecules on human cells. Dr is associated with recurring urinary tract infection (UTI), but the distribution of Dr subtypes among uropathogenic Escherichia coli causing UTI among otherwise healthy women has yet to be described. A total of 787 UTI and fecal E. coli isolates from college women were screened for the presence of Dr sequences (drb). Fifteen percent of UTI strains were drb positive, compared to 5% of fecal strains. The adhesin (E gene) subtype of each drb-positive strain was determined by type-specific PCR followed by restriction enzyme analysis. Among 78 drb-positive strains, we found 14 (18%) afaE1, 1 (1.3%) afaE2, 1 (1.3%) afaE3, 9 (12%) draE, 9 (12%) draE-afaE3 hybrid, 1 (1.3%) daaE, 32 (41%) afaE5, 4 (5.1%) F131 E gene-like, and 7 untypeable strains. All untypeable E genes were cloned and sequenced, revealing four additional new classes of E genes, including two similar to the previously identified nonfimbrial E series. While a great range of diversity exists among the E genes, restriction fragment length polymorphism analysis demonstrated that all of these drb operons share a highly conserved gene structure. The most common subtype, afaE5, occurred three times as often among UTI than fecal strains. Over half of the drb-positive strains and 80% of those positive for afaE5 have the same virulence signature (positive for aer, kpsMT, ompT, and fim), suggesting an association of this profile with UTI pathogenesis.

Transmission of uropathogens between sex partners.

Epidemiologic evidence and several case reports suggest that Escherichia coli causing urinary tract infection (UTI) may be transmitted between sex partners. In order to test this hypothesis, urinary, vaginal, and fecal E. coli isolates from 19 women with UTI were compared with E. coli found in random initial voids from their most recent male sex partner. E. coli was isolated from 4 of 19 male sex partners. In each case, the E. coli isolated from the man was identical by pulsed-field gel electrophoresis and bacterial virulence profile to the urinary E. coli from his sex partner.

Virulence characteristics of Escherichia coli causing first urinary tract infection predict risk of second infection.

Escherichia coli causes most urinary tract infections (UTIs) in ambulatory populations. Several bacterial virulence factors occur more frequently among urinary E. coli isolates than among fecal isolates, but none have been reported to predict risk of second UTIs. DNA hybridization was used to characterize the bacterial virulence profiles of urinary E. coli isolates from 174 women with first UTI and compared for risk of second UTI. Of the women, 28 (16%) had a culture-confirmed second UTI within 6 months of a negative test-of-cure. Three virulence factors were associated with a significantly lower risk of second UTI: cytotoxic necrotizing factor (relative risk [RR] = 0.0; 95% confidence interval [CI], 0.0, 0.42); hemolysin (RR, 0.10; 95% CI, 0.01, 0.69), and S fimbrial adhesin (RR, 0.25; 95% CI, 0.06, 1.00). Dr binding was associated with a 2-fold increased risk of second UTI (RR, 2.30; 95% CI, 1.23, 4.29). Half of all paired first and second UTI isolates from the same subject were apparently the same.

Bacterial virulence characteristics of Escherichia coli isolates from first-time urinary tract infection.

The frequency of nine potential Escherichia coli urinary tract infection (UTI) virulence factors was investigated among 216 isolates from 208 women 18-40 years old with first-time UTI. Factors were afimbrial adhesions I-IV and F1845 pili (drb), aerobactin (aer), group II capsules (kpsMT), cytotoxic necrotizing factor 1 (cnf1), alpha-hemolysin (hly), outer membrane protease T (ompT), Pap and Prs pili (prf), S fimbriae (sfa), and type 1 pili (fim). Women were enrolled at two sites. Pairwise comparisons found 14 statistically significant associations between virulence genes after correcting for multiple comparisons. This is the first report of five associations: aer and drb, kpsMT and ompT, ompT and cnf1, ompT and sfa, and prf and ompT. As ompT is not closely linked genetically to kpsMT, cnf1, prf, or sfa, ompT may be functionally linked with one or more of these other virulence factors.