Escherichia coli biofilm formation and recurrences of urinary tract infections in children.

It has been suggested that biofilm formation by uropathogenic Escherichia coli (UPEC) isolates is associated with recurrence and persistence of urinary tract infection (UTI). We compared the in vitro biofilm formation of UPEC isolates from children with acute or recurrent UTI. Employing 206 consecutive clinical UPEC isolates from children with proven UTI, i.e., pyelonephritis (n = 78), recurrent pyelonephritis (n = 10), cystitis (n = 84) or recurrent cystitis (n = 34), we applied 1 % crystal violet staining to polystyrene microtitre plates at 72 h and measured the optical density (OD) values. The method had been validated to measure biofilm formation against confocal laser scanning microscopy and scanning electron microscopy. The OD values were lower in the recurrent cystitis group than in the other groups (mean OD 0.36, SD 0.21 vs mean 0.47, SD 0.36, P = 0.04) and higher in the recurrent pyelonephritis group than in the other groups (mean OD 0.69, SD 0.33 vs mean OD 0.44, SD 0.34, P = 0.006) indicating biofilm formation of strains causing recurrent pyelonephritis. It appears that the properties of UPEC isolates required for effective biofilm growth on an abiotic surface are important for recurrent pyelonephritis, but not for recurrent cystitis. It would be valuable in the future to analyze whether the biofilm properties of E. coli observed in vitro predict a slower clinical response to antimicrobial treatment and increased renal scar formation after UTI.

Biofilm formation and virulence of uropathogenic Escherichia coli in urine after consumption of cranberry-lingonberry juice.

Cranberry-lingonberry juice (CLJ) was effective in preventing urinary tract infections (UTIs) in our earlier randomized clinical trial. We aimed to test whether consumption of CLJ at a similar dose to earlier reduces the biofilm formation and virulence of uropathogenic Escherichia coli in urine. Twenty healthy women drank 100 ml of CLJ daily for two weeks. Urine samples were obtained 2-4 hours after the last dose. Control samples were taken after a one-week period without berry consumption. Biofilm formation of 20 E. coli strains was measured at 72 hours by the polystyrene microtitre plate method. Quantitative real-time PCR analyses were performed for selected genes. Four of the 20 clinical strains produced more biofilm in urine after CLJ consumption (P < 0.05) and one produced less. Expression levels of the pga, cpxA, fimA and papF genes did not differ between bacteria grown in control urine and urine obtained after CLJ consumption, except for pga gene expression, which was reduced in one strain after CLJ (P = 0.04). It appears that the effect of CLJ in preventing UTIs is not explained by mechanisms that reduce biofilm formation or the expression of selected virulence genes of Escherichia coli in urine.

Biofilm formation by Escherichia coli isolated from patients with urinary tract infections.

AIMS: The significance of biofilm formation for the clinical picture of urinary tract infections (UTI) is largely unknown. We wanted to find out whether Escherichia coli (E. coli) strains isolated from UTI patients differ in their ability to form biofilms and whether this ability is associated with the clinical presentation of UTI. MATERIAL AND METHODS: 70 E. coli strains were isolated from patients with cystitis (43 strains), pyelonephritis (11 strains) and urosepsis (16 strains) and biofilm formation was assessed on polystyrene microtiter plates by measuring the optical density (OD) of the attached material after 72 h of incubation and crystal violet staining of the bacteria. The formation of organized biofilm structures and the viability of the attached bacteria were verified by scanning electron microscopy and confocal scanning laser microscopy in a subsample of 22 strains. RESULTS: 31% of the E. coli strains formed a biofilm. The strains isolated from patients with pyelonephritis had higher ODs than those from patients with cystitis (difference of the means 0.19, 95% confidence limits (CL) 0.06 - 0.32, p = 0.02). The E. coli strains susceptible to antibiotics had higher ODs than the resistant strains (difference of the means 0.21, 95% CL 0.03 - 0.27, p = 0.016). CONCLUSIONS: The ability of bacteria to persist and grow in a biofilm seems to be one of the important factors in both the resistance to antibiotics and the severity of urinary tract inflammation.

Promoter region polymorphism of the CD14 gene (C-159T) is not associated with psoriasis vulgaris.

Keratinocytes of psoriatic skin show aberrant expression of membrane-bound CD14 (mCD14). In addition, soluble CD14 (sCD14) is elevated in the sera of psoriatic patients. The mechanisms leading to increased CD14 expression and secretion in psoriasis are poorly understood. A bi-allelic polymorphism in the promoter region of the CD14 gene controls CD14 expression on monocytes and sCD14 levels in the sera of healthy subjects. In this context, we explored the CD14 promoter region genotypes of 63 Finnish patients with psoriasis and 126 non-psoriatic controls using a new ARMS-PCR method. No differences in the CD14 genotype frequencies were found between the groups. Thus, our results suggest that the enhanced CD14 expression in psoriasis is not attributable to functional variants of CD14 (-159C/T).

Serotypes of Chlamydia trachomatis and risk for development of cervical squamous cell carcinoma.

CONTEXT: Human papillomavirus (HPV) infection has been established as a cause of cervical cancer. Epidemiologic studies suggest that Chlamydia trachomatis infection also confers increased risk for cervical squamous cell carcinoma (SCC). Whether this risk is serotype-specific is unknown. OBJECTIVE: To study the association between exposure to different C trachomatis serotypes and subsequent development of cervical SCC. DESIGN AND SETTING: Longitudinal, nested case-control study within a cohort of 530 000 women who provided samples to serum banks in Finland, Norway, and Sweden. The data files were linked to respective national cancer registries. SUBJECTS: One hundred twenty-eight women who had developed invasive cervical SCC at least 12 months following serum donation. Each case had 3 matched controls. MAIN OUTCOME MEASURE: Risk for the development of cervical SCC by IgG antibodies to 10 different C trachomatis serotypes, adjusted for antibodies to HPV types 16, 18, and 33 and for serum cotinine levels. RESULTS: Of specific C trachomatis serotypes, serotype G was most strongly associated with SCC (adjusted odds ratio [OR], 6.6; 95% confidence interval [CI], 1. 6-27.0). Other serotypes associated with SCC were I (OR, 3.8; 95% CI, 1.3-11.0) and D (OR, 2.7; 95% CI, 1.3-5.6). Presence of serum IgG antibodies to more than 1 serotype increased the adjusted ORs for SCC (P<.001 for trend). CONCLUSIONS: Chlamydia trachomatis serotype G is most strongly associated with subsequent development of cervical SCC. Increasing numbers of exposures to different C trachomatis serotypes also increases risk. Our results strengthen the evidence that there is a link between past C trachomatis infection and cervical SCC.

Effect of xylitol on growth of Streptococcus pneumoniae in the presence of fructose and sorbitol.

Xylitol is effective in preventing acute otitis media by inhibiting the growth of Streptococcus pneumoniae. To clarify this inhibition we used fructose, which is known to block similar growth inhibition observed in Streptococcus mutans. In addition, we evaluated the efficacy of sorbitol in inhibiting the growth of pneumococci, as sorbitol is widely used for indications similar to those for which xylitol is used. The addition of 5% xylitol to the growth medium resulted in marked growth inhibition, an effect which was totally eliminated in the presence of 1, 2.5, or 5% fructose but not in the presence of 1 or 5% glucose, 1% galactose, or 1% sucrose. This finding implies that xylitol-induced inhibition of pneumococcal growth is mediated via the fructose phosphotransferase system in a way similar to that in which mutans group streptococcal growth is inhibited. The addition of sorbitol at concentrations of 1, 2.5, or 5% to the growth medium did not affect the growth of pneumococci and neither inhibited nor enhanced the xylitol-induced growth impairment. Thus, it seems that xylitol is the only commercially used sugar substitute proven to have an antimicrobial effect on pneumococci.

In vitro antibiotic susceptibility of Francisella tularensis isolated from humans and animals.

The in vitro susceptibility of 38 strains of Francisella tularensis (biovar F. tularensis palaearctica) was determined using Etests on cysteine heart agar plates with 2% haemoglobin. All strains were susceptible to the antibiotics traditionally used to treat tularaemia, such as streptomycin (MIC(90) 4.0 mg/L), tetracycline (MIC(90) 0.38 mg/L) and chloramphenicol (MIC(90) 0.38 mg/L), and to aminoglycosides, such as tobramycin (MIC(90) 1.5 mg/L) and gentamicin (MIC(90) 1.0 mg/L). The quinolones examined had low MIC(90)s: ciprofloxacin, 0.016 mg/L; levofloxacin, 0.016 mg/L; grepafloxacin, 0.047 mg/L; and trovafloxacin, 0.032 mg/L. In contrast, all the strains were resistant to beta-lactams and azithromycin. Quinolones thus seem to be promising drugs for the treatment of tularaemia.

HLA-DQA1 alleles and the presence of Helicobacter pylori antibodies.

Recent reports suggest that the HLA-DQA1 gene may be important in determining susceptibility to and outcome of Helicobacter pylori infection. To determine if there is an association between HLA-DQA1 alleles and H. pylori antibodies, DQA1 alleles and H. pylori-specific antibodies were determined in 199 random subjects of Finnish origin (mean age 43 years, range 22-69 years). H. pylori-specific class IgG antibodies were measured using the EIA method (Pyloriset-EIA-G, Orion Diagnostica, Espoo, Finland). HLA-DQA1 typing was carried out using PCR-SSP (PCR with sequence-specific primers). There were 64 subjects with H. pylori-specific class IgG antibodies (ab+) and 135 subjects without H. pylori-specific class IgG antibodies (ab-). Gene and phenotype frequencies of HLA-DQA1 alleles were similar in the ab+ and ab- subjects (P = NS). The data suggest that no single HLA-DQA1 allele is associated with the presence of serum antibodies against H. pylori.

High prevalence of rheumatoid factor in community-based series of patients with rheumatoid arthritis meeting the new (1987) ARA criteria: RF-negative non-erosive rheumatoid arthritis is very rare.

The aim of the study was to assess the prevalence of rheumatoid factor (RF) in a community-based rheumatoid arthritis (RA) series. The subjects of the series represented prevalent RA cases in the Kuusamo community in Northern Finland with 13,000 adult inhabitants. The patients were selected from the official Finnish data registers and from among the subjects who had consulted the local general practitioners due to rheumatic complaints in the recent years, using the American Rheumatism Association (ARA) 1987 classification criteria for inclusion. For this study, ninety-five out of the 103 RA patients so found were RF-tested by immunoturbidimetry. At the time of the study. 71 (75%) of the 95 cases were RF positive, 83 (87%) being 'ever' positive (in one case the early RF status was unclear). Our result contrasts with the much lower prevalence figures (25-60%) obtained from the earlier cross-sectional population-based RA studies, which have used the ARA 1958 definite RA as the inclusion criterion of the subjects. All the eleven patients with RF-negative RA had erosive joint disease. The RF-negative RA patients had a significantly lower frequency of HLA-DR4 (18%) than the RF-positive ones (58%), p < 0.05. We found a high frequency of RF among prevalent community-based RA cases meeting the ARA criteria. According to our results, RF-negative non-erosive RA is very rare among cases selected with the above methods.

Restricted and individual usage of T-cell receptor beta-gene variables in nickel-induced CD4+ and CD8+ cells.

Nickel allergy is manifested as contact allergic eczema elicited by delayed-type hypersensitivity, the reaction being mediated by T lymphocytes. We examined the T-cell receptor (TCR) beta-chain variable gene segment (Vbeta) use of nickel-induced CD4+ and CD8+ T cells in the peripheral blood of nickel-sensitive and nonsensitized subjects. The results show that each patient had an individual Vbeta repertoire overexpressed, these being in CD4+ cells Vbeta10 and Vbeta13 (in subject A); Vbeta1, Vbeta2, Vbeta13 and Vbeta21 (subject B); Vbeta1 and Vbeta10 (subject C); Vbeta9 and Vbeta19 (subject D). Thus, no single Vbeta gene dominated in a majority of the CD4+ samples. The Vbeta genes overexpressed in patient CD8+ nickel-induced T cells were Vbeta1 (in subject A), Vbeta1 (subject B), Vbeta1 and Vbeta2 (subject C) and Vbeta7 (subject D), domination of Vbeta1 being seen in most of the CD8+ samples (75%). No specific overexpression of any Vbeta genes in the nickel-allergic subjects was found in comparison with the non-sensitized subjects. In conclusion, an individual pattern of restricted Vbeta genes was induced with nickel in CD4+ and CD8+ T cells in each nickel allergy patient.

TAP1 and TAP2 genes in nickel allergy.

The study was undertaken to see whether TAP1 and TAP2 (transporter associated with antigen processing) genes are involved in susceptibility to nickel allergy. The products of these genes are important in antigen transport and processing, making them candidates for disease susceptibility. Fifty-five nickel-sensitive and 54 non-sensitive subjects were TAP1- and TAP2-typed by amplification refractory mutation system - polymerase chain reaction. The allele and phenotype frequencies of TAP2B were significantly (p = 0.019 and 0.012, respectively) increased in nickel-sensitive subjects versus controls. Relative risk (RR) for TAP2B was 2.7 and etiological factor (EF) = 0.46. The allele frequency of TAP2C was decreased among the nickel-sensitive subjects versus controls (p = 0.016). RR for TAP2C was 0.18. In conclusion, TAP2B increases the risk for nickel allergy, the results suggesting a considerably high EF.

HLA markers in a community-based rheumatoid arthritis series.

We wanted to investigate whether rheumatoid arthritis (RA) patients, defined by the American College of Rheumatology (ACR) 1987 criteria and selected from one community by the help of the official Finnish data registers, share the common HLA susceptibility genes. The HLA frequencies of 88 RA patients representing 85% of the prevalent cases of RA in the community were compared with those of 188 healthy controls. Fifty-four per cent of the index cases with RA had DR4 compared with 30% of the healthy controls (P <0.001). The 'RA susceptibility sequence' was found in 75% of the DRB1 genes in the index cases, but it did not correlate with the severity of the disease. The frequency of DR3 was not increased in RA patients but it was associated with features of severe disease, that is, with a high erythrocyte sedimentation rate (P<0.05), extra-articular disease (P<0.01) and prostheses in large joints (P<0.05). According to our results community-based RA patients satisfying the new ACR criteria show the common DR4 association. DR3 was the only HLA allele which showed some disease-modifying effect correlating with the severity of RA.

The frequency of QAP2.1 is increased in psoriasis vulgaris patients but no unusual linkage between QAP/DQA1 or QBP/DQB1.

Psoriasis vulgaris is a chronic skin disease with a genetic and immunological background. We have previously defined the two most frequent risk haplotypes in Finns: A2,B13,Cw6,DR7,DQA1*0201 and A1,B17,Cw6,DR7,DQA1*0201. The aim of this study was to further examine whether the flanking regions, URRs of DQ (QAP and QBP) and TAP1 and TAP2 genes are involved in susceptibility to psoriasis. The frequency of QAP2.1 was increased in psoriatics as compared with controls (Pc = 3.6 x 10(-2), RR = 5.0), and the frequency of QAP4.1 was decreased in psoriasis patients (Pc = 4.2 x 10(-2)). The frequency of the phenotype combination Val/Ile at position 379 of TAP2 was decreased in patients (Pc = 1 x 10(-2)). The allele and phenotype frequencies of TAP1 and TAP2 genes were not different between these groups. Haplotypes A2, B13,Cw6,DR7,DQA1*0201,QAP2.1 and A1,B17,Cw6, DR7,DQA1*0201,QAP2.1 are the two most frequent HLA marker haplotypes for psoriasis vulgaris in Finns, Cw6, DR7, DQA1*0201 and QAP2.1 being the most important single alleles for the risk of this disease.

HLA five-locus haplotypes in Finns.

The extreme polymorphism of HLA genes makes them a powerful tool for distinguishing between different genetic populations. Five-locus HLA haplotypes of Finns (from Oulu, Northern Finland) are described here in order to characterize further the migration pathways of the population to Finland after the Ice Age. From random families, 364 haplotypes were obtained. The most frequent Finnish haplotype A3,Cw4,B35,DR1,DQ1 (7.7%) is a Caucasoid ancestral haplotype and is shared with Italians of Celtic and non-Celtic origin. The haplotype A1,Cw7,B8,DR3,DQ2, which occurs in 4.7% of Finns, is the most frequent haplotype in Caucasoids. The haplotypes A3,Cw7,B7,DR2,DQ1 (3.6%) and A2,Cw7,B7,DR2,DQ1 (2.5%) are shared with several Caucasoid populations and the latter also with Jamaican blacks. A2,Cw5,B44,DR5,DQ3 (0.8%) is shared with Italians of Celtic and non-Celtic origin, A2,Cw6,B13,DR7,DQ2 (1.1%) with Caucasoids in the USA and A9,Cw4,B35,DR1,DQ1 (0.8%) with Mongoloids. The haplotypes A2,CW3,B62,DR4,DQ3 (3.0%), A2,Cw2,B27,DR8,DQ4 (1.7%), A2,Cw3,B62,DR6,DQ1 (1.4%) and A2,Cw1,B27,DR4,DQ3 (1.4%) were also found to be among the most frequent in the Finnish population. The most frequent HLA haplotypes are consistent with the postulated ancient migration of populations from southern Scandinavia and Germany to Finland, the most frequent haplotype suggesting a common Celtic origin and one less frequent haplotype suggesting an influence from the east.

HLA risk haplotype Cw6,DR7,DQA1*0201 and HLA-Cw6 with reference to the clinical picture of psoriasis vulgaris.

Psoriasis vulgaris has HLA associations. We have previously defined HLA-Cw6,DR7,DQA1*0201 as the central element of the risk haplotypes for psoriasis. On the other hand, Cw6 as a single gene has the strongest association with psoriasis. The aim of this study was to determine whether the risk haplotype and Cw6 correlate with the clinical parameters of the disease. The series consisted of 64 patients and the clinical parameters were age at onset, family history of psoriasis, arthritis and the frequency of inpatient treatment. The HLA risk haplotype Cw6,DR7,DQA1*0201 had previously been found in 30% and Cw6 alone in 54% of the patients. The presence of Cw6 correlated with early age at onset (Pc = 0.01). The presence of the risk haplotype correlated with a positive family history of psoriasis among the first-degree relatives (Pc = 0.02) and an overall positive family history (Pc = 0.04), but Cw6 had a stronger correlation with an overall positive family history (Pc = 0.01). There were no positive correlations with arthritis or the number of inpatient treatment periods. Only type I psoriasis was associated with Cw6 (Pc = 0.0006). In conclusion, Cw6 and the haplotype Cw6,DR7,DQA1*0201 are important in the heredity of psoriasis vulgaris, but the presence of Cw6 alone is sufficient to indicate a clinically significant risk for psoriasis.

HLA-G polymorphism and allelic association with HLA-A in a Finnish population.

The polymorphism of the HLA-G gene can be identified by PCR-RFLP analysis. This short communication describes the PCR-RFLP analysis of HLA-G polymorphisms in exons 2 and 3 and the association of different HLA-G and HLA-A alleles in 26 healthy Finnish families.

Immunogenetic profile of psoriasis vulgaris: association with haplotypes A2,B13,Cw6,DR7,DQA1*0201 and A1,B17,Cw6,DR7,DQA1*0201.

Psoriasis vulgaris is a skin disease with an immunological and genetic background present in 1-3% of the population. We studied the genetic susceptibility to psoriasis vulgaris in Finns with serological HLA typing and genomic HLA class II typing of the DQ and DP loci to evaluate the risk of developing psoriasis. The haplotypes most frequently distinguishing between psoriatics and controls were those that carried Cw6 (P < 10(-8)), DQA1*0201 (P = 9.3 x 10(-6)) and DR7 (P = 3.9 x 10(-5)). The two most frequent marker haplotypes were A2,B13,Cw6,DR7, DQA1*0201 and A1,B17,Cw6,DR7,DQA1*0201, which were not found among the control subjects. A deficit of haplotype B8,DR3,DQ2 (2 out of 124 in the patients versus 15 out of 106 in the controls, P = 1.5 x 10(-4)) was found, and this was in accordance with a slightly decreased frequency of DQA1*0501 (P = 3.1 x 10(-2)), which was usually linked with this haplotype. These results stimulate the research for a genetic resistance factor in psoriasis. Thus, this report sheds further light on the immunogenetic background of psoriasis in Finland. We conclude that the inheritance of psoriasis has a polygenic mode, in which the Cw6,DR7,DQA1*0201 combination seems to be important (P = 7.5 x 10(-7), relative risk 24.4, aetiological factor 0.29).

Insulin gene region-encoded susceptibility to IDDM maps upstream of the insulin gene.

The gene region on chromosome 11p15.5 known to be involved in insulin-dependent diabetes mellitus (IDDM) susceptibility was recently mapped to a 4.1-kilobase region including the insulin gene. The region contains 10 candidate polymorphisms that are in strong linkage disequilibrium. By genotyping 7 of these 10 polymorphisms and the tyrosine hydroxylase microsatellite in Finnish Caucasoid IDDM patients and control subjects, we demonstrate that many of the polymorphisms found to be associated with IDDM in other Caucasoid populations do not show any association in this Finnish population. Of the polymorphisms typed, only those at -23 Hph I and the variable number of tandem repeats (VNTR) sites confer significant relative risk. Furthermore, we have demonstrated that the -23 Hph I polymorphism cannot explain the association. Comparison of the genotypic patterns observed here and previously suggests that the VNTR is the most likely candidate for IDDM2. The VNTR is located adjacent to defined regulatory DNA sequences affecting insulin gene expression, which suggests a possible effect on expression of insulin or one of the neighboring genes, tyrosine hydroxylase or insulin-like growth factor 2.

Alanine at position 73 of HLA-C is associated with psoriasis vulgaris in Finland.

A close association was found between a specific sequence of HLA-C and psoriasis vulgaris in Finnish patients (chi 2 = 18.4, P = 1.78 x 10(-5)). This sequence codes for alanine at position 73 of the HLA-C molecule in the antigen binding cleft, and alanine may play a role in susceptibility to the disease.

Different distribution of T cell receptor beta-chain haplotypes in mixed connective tissue disease and systemic lupus erythematosus.

Mixed connective tissue disease (MCTD) and systemic lupus erythematosus (SLE) are autoimmune diseases with a genetic background, and it is reasonable to suggest that aberrations in T cell receptor (TCR) genes could contribute to these diseases, as they play an important role in immune regulation. We studied TCR beta-chain gene segments V beta 8, V beta 11 and C beta with restriction fragment length polymorphism (RFLP) in MCTD and SLE patients and controls. Haplotypes could be assigned in individuals who were homozygous for two or three of these three loci, whereupon the haplotype 2/25/10 (V beta 8/V beta 11/C beta) was found to be under-represented in MCTD (P = 0.029). The frequencies of individual alleles in both groups were similar to those of the controls, whereas the number of homozygotes within V beta 8 gene (23/23 kb and 2/2 kb) was increased in MCTD (P = 0.028). It is concluded that the distribution of TCR beta-chain genes could be aberrant in MCTD and could play a role in susceptibility, whereas the TCR beta-chain gene distribution in the SLE patients did not differ from that of the controls.