Prevalence of antibodies against Chlamydia trachomatis and incidence of C. trachomatis-induced reactive arthritis in an early arthritis series in Finland in 2000.

OBJECTIVE: To study the prevalence of different serotypes of Chlamydia trachomatis antibodies and the incidence of C. trachomatis-induced reactive arthritis (ReA) among patients with early arthritis in a defined population. METHODS: Serum samples were collected from a cohort of 122 adult patients in the age group 18-65 years included in the Kuopio 2000 Arthritis Survey. Antibodies against C. trachomatis serotypes C, E, and G were studied using enzyme immunoassay (EIA) tests among patients and in a control cohort of 78 adults without any joint symptoms. The incidence assessment for Chlamydia-induced ReA was based on a ligase chain reaction (LCR) test in urine and clinical symptoms and signs appropriate for ReA. RESULTS: Of 122 patients, with the baseline diagnosis of rheumatoid arthritis (RA) in 11, spondyloarthropathy (SpA) in 28, and undifferentiated arthritis (UA) in 83 cases, 42 (34%) showed immunoglobulin (Ig)G or IgA antibodies against at least one serotype C, E, or G. Among the patients with UA the prevalence was significantly increased compared with the controls (p = 0.010). C. trachomatis-induced ReA arthritis was diagnosed in only three patients with the LCR test. On this basis the incidence of C. trachomatis-induced arthritis was 5.4/100 000 [95% confidence interval (CI) 1.1-15.7] in the age group 18-65 years. CONCLUSION: Antibodies against C. trachomatis were most common in patients with UA reflecting the fact that cases with chlamydia-induced ReA are included in this subgroup.

Random amplified polymorphic DNA (RAPD) analysis of Escherichia coli strains: comparison of urinary and concomitant blood isolates of urosepsis patients.

The discriminatory power of random amplified polymorphic DNA (RAPD) analysis was assessed for detection of intraspecies variation in Escherichia coli strains of clinical origin. Three primers (OPF 5, OPF 7 and OPF 8) were preselected from commercial 10-mer primers by the number of distinct bands obtained. These primers were used in testing 26 urinary and 13 blood isolates from 26 patients and E. coli ATCC 25922, OPF 5, OPF 7 or OPF 8 alone separated the strains into 15 to 21 RAPD types. A combination of the results of the three primers gave 25 RAPD types. When blood and urine isolates of each patient were analysed in parallel, all blood-urine pairs were found identical, and with one exception they were also unique. RAPD analysis had a high discriminatory power. It separated the strains equally well or better than ribotyping, and obviously better than serotyping which grouped the urine strains into 8 serogroups leaving 18 strains untypable or incompletely typed. Thus, to verify the identity or non-identity of isolated E. coli strains, RAPD analysis was shown to be a sensitive and reproducible technique which is technically less demanding, more rapid and more economical than either serotyping or ribotyping. However, in its present application, this technique cannot fully replace determination of the serotype or virulence factors which may show correlations with different manifestations of infection.

High incidence of Alloiococcus otitis in otitis media with effusion.

BACKGROUND: The etiology of otitis media with effusion (OME) is unclear. Although the majority of effusions show inflammation, culture methods yield positive results for bacteria in only 20 to 30% of cases. METHODS: The polymerase chain reaction was used for detection of three upper respiratory tract pathogens, Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pneumoniae, and a fairly recently described bacterium, Alloiococcus otitis (A. otitidis), that is solely found in OME. The study included 67 middle ear effusions that were collected from 48 pediatric OME patients during ventilation tube placement. RESULTS: PCR tested positive for 57 (85.1%) of the middle ear effusions. Thirty-one (46.3%) A. otitis-, 12 (17.9%) H. influenzae-, 25 (37.3%) M. catarrhalis- and 14 (20.9%) S. pneumoniae-positive effusions were obtained. All four study organisms showed similar distribution in effusions of various duration (P = 0.72) and in different effusion types (P = 0.59). Only the proportion of M. catarrhalis-positive effusions was lowered by recent antimicrobial therapy (P < 0.05). Although the study organisms had equal distributions among singly and multiply positive specimens (P = 0.90), A. otitis was detected significantly more often with one of the three other species (15 of 19, 78.9%) than the other species with each other (4 of 19, 21.1%, P < 0.001). CONCLUSIONS: The findings suggest a bacterial etiology for OME. Association of A. otitis with the three other species implies that this organism might have the capability of augmenting bacterial colonization in the middle ear.

Recurrent Sphingomonas paucimobilis -bacteraemia associated with a multi-bacterial water-borne epidemic among neutropenic patients.

A cluster of septicaemias due to several water-related species occurred in a haematological unit of a university hospital. In recurrent septicaemias of a leukaemic patient caused by Sphingomonas paucimobilis, genotyping of the blood isolates by use of random amplified polymorphic DNA-analysis verified the presence of two distinct S. paucimobilis strains during two of the separate episodes. A strain of S. paucimobilis identical to one of the patient's was isolated from tap water collected in the haematological unit. Thus S. paucimobilis present in blood cultures was directly linked to bacterial colonization of the hospital water system. Heterogeneous finger-printing patterns among the clinical and environmental isolates indicated the distribution of a variety of S. paucimobilis clones in the hospital environment. This link also explained the multi-microbial nature of the outbreak.

Virulence characteristics of Escherichia coli in nosocomial urinary tract infection.

We examined 148 strains of Escherichia coli isolated from the urine from patients with nosocomial urinary tract infection (UTI). The prevalence of P fimbriation was only 11.5%. Of the strains, 17.6% expressed non-P M(R) adhesins (defined as strains expressing mannose-resistant but not P-specific hemagglutination); 33.1% produced hemolysin, and 15.2% expressed type 1C fimbriae. O6 was the most common group of O antigens (12.2%), closely followed by O75 (9.5%); both of these groups are relatively uncommon (4.5% and 1%, respectively) in fecal strains isolated from healthy adults. Of the strains with O6 and O75 antigens, 78.8% and 79% produced hemolysin, but of all other strains causing UTI, only 21% produced hemolysin. Of the strains with O6 antigens, 61% expressed non-P M(R) adhesins, but only 12% of all other strains causing UTI expressed non-P M(R) adhesins. There were no significant differences in the prevalence of virulence properties between strains isolated from patients with or without an underlying medical illness or between strains causing different clinical categories of UTI. We conclude that the prevalence of bacterial virulence factors is low among patients with nosocomial UTI.

P fimbriation of Escherichia coli strains from patients with urosepsis demonstrated by a commercial agglutination test (PF TEST).

We examined 138 Escherichia coli strains isolated from cultures of blood specimens from urosepsis patients (n = 78) and nonurosepsis patients (n = 30) and from fecal specimens of a healthy control group (n = 30) for P fimbriation with a mannose-resistant hemagglutination test, an indirect immunofluorescence assay, and a new commercial particle agglutination test (PF TEST; Orion Diagnostica, Espoo, Finland). About 60% of the strains in the urosepsis group were P fimbriated with all tests, with no significant differences observed between patients with or without known predisposing factors. In the non-urosepsis-associated and fecal strains, the incidence of P-fimbriated E. coli strains varied from 3.3% (PF TEST) to 33% (indirect immunofluorescence assay), depending on the test method. The PF TEST proved easy to perform and demonstrated a specificity and a sensitivity equal to those of the alternative tests. The PF TEST can be recommended for routine clinical use to detect virulent urinary E. coli strains.

Low virulence of Escherichia coli strains causing urinary tract infection in renal disease patients.

The distribution of urinary bacterial species was determined and the virulence factors of Escherichia coli urinary strains analysed by molecular and phenotyping methods in episodes of urinary tract infection in renal disease patients (n =68) in comparison with other immunocompromised patients (n =59) and non-immunocompromised patients (n =21). Escherichia coli was isolated in 116 (78%) of the 148 patients, being the species most frequently isolated in all groups (75% of renal disease patients, 76% of other immunocompromised patients, 95% of non-immunocompromised patients). All other pathogens showed a similar distribution in the renal disease and other immunocompromised patient groups. All virulence factors of Escherichia coli tested for (genes for G adhesins, expression of MR adhesins, production of haemolysin, presence of certain O and K antigens) were found more often in non-immunocompromised than in immunocompromised patients. The factors allowing the highest degree of discrimination between immunocompromised and non-immunocompromised patients were the prevalence of genes for G adhesins (35% vs. 65%) and expression of MR adhesins (32% vs. 55%). It is concluded that there is a lower prevalence of G adhesins and MR adhesins in Escherichia coli strains from immunocompromised patients than non-immunocompromised patients, suggesting that less virulent Escherichia coli strains may cause urinary tract infections more frequently in renal disease patients and other immunocompromised patients. Moreover, the spectrum of urinary pathogens other than Escherichia coli is similar in both immunocompromised patient groups investigated.

Community-acquired pyelonephritis in adults: characteristics of E. coli isolates in bacteremic and non-bacteremic patients.

Escherichia coli strains isolated from the urine in 49 consecutive episodes of community-acquired pyelonephritis in adult women were characterized for adhesins and hemolysin production. The mean age of the patients was 56 years and 47% had at least 1 compromising condition. P fimbriae was found in 67% and hemolysin production in 35% of the strains; these figures were significantly (p < 0.001) higher than the corresponding figures (11% for each) among 287 strains isolated from stool of healthy adults (Siitonen A. J Infect Dis 1992; 166: 1058-1065). The prevalence of Non-P mannose-resistant adhesins and type 1C fimbriae was low (4 and 8%, respectively) and did not differ significantly from the corresponding prevalences (1 and 7%) in healthy adults. 74% fo the pyelonephritic (but only 22% of the stool) isolates had at least 1 of these 4 virulence factors (p < 0.001) and 37% and 7%, respectively, had at least 2 (p < 0.001). Nevertheless, the strains represented a wide variety of O:K serotypes without any indication of specially virulent clones. Of the 49 patients 15 had concomitant bacteremia, and in all except 2 compromised elderly patients the urinary and blood isolates were identical.

Recurrence of urinary tract infections in adult patients with community-acquired pyelonephritis caused by E. coli: a 1-year follow-up.

In a prospective study, 42 women were followed for recurrence of urinary tract infections (UTIs) for 1 y after an index episode of community-acquired pyelonephritis caused by Escherichia coli. Altogether, 26 repeat episodes were detected. Of these, 20 occurred at least 1 month after the index episode and were regarded as recurrences. In all, 40%, (17 of 42) of the women had recurrences. An earlier history of UTI increased the risk of recurrence: 52%, of the 29 women with previous UTI had at least 1 recurrence, compared with 15%, of the 13 patients without previous UTI. E. coli caused the majority (73%) of the recurrences. Genotype comparisons by RAPD-PCR analysis between E. coli isolates from a patient showed that 75%. of the original and recurrent strains were genetically non-identical. Of the 54 E. coli strains, 42 were carrying genes coding for G adhesins of P fimbriae: 40 isolates carried class II, I class III and 1 carried both class II and III G adhesin genes. Each of the virulence-associated factors (genes for G adhesins, MRHA, haemolysin, type 1C fimbriae, and O and K antigens) was evenly distributed among E. coli isolates of index episodes, independent of the recurrences. The index isolates, however, had more virulence-associated factors than did the isolates from the recurrences which were mainly due to lower UTIs.

Characteristics of Escherichia coli in acute community-acquired cystitis of adult women.

The characteristics of Escherichia coli isolated from the urine in 178 consecutive episodes of community-acquired cystitis in adult women were studied and compared with strains isolated from stools of 287 healthy adults. The prevalence of each of the previously described virulence-associated factors for urinary tract infection was significantly higher in the cystitis than in the stool isolates. The figures were 25.3% and 10.8%, respectively, for P fimbriation; 19.7% and 1% for Non-P MR adhesins, 13.5% and 7.3% for type 1C fimbriae and 22.5% and 10.8% for hemolysin production. 54% of the cystitis strains (but only 21.6% of the stool isolates) had at least 1 of these virulence-associated factors. These factors were mutually associated in a non-random manner; the association of P fimbriae with K1 and of Non-P MR adhesins and type 1C fimbriae with K5 capsules were highly significant. However, no clones specifically associated with cystitis could be identified. No significant differences were found between isolates from the first or recurrent UTI, or from younger or older, compromised or non-compromised patients. We conclude that P fimbriae, Non-P MR adhesins, type 1C fimbriae and hemolysin production all contribute to the establishment of cystitis in adults.

Recurrence of urinary tract infection in a primary care setting: analysis of a 1-year follow-up of 179 women.

In a prospective study, 179 adult women (age range, 17-82 years) were followed up for 12 months after an index episode of community-acquired cystitis caused by Escherichia coli. Episodes of symptomatic urinary tract infection (UTI) were recorded, and urinary isolates were compared with the index episode isolate; 147 UTI episodes were detected during the follow-up. Of these episodes, 131 were classified as recurrences occurring at least 1 month after the index episode; 44% of the patients had recurrences. A history of UTI increased the risk of recurrence; only 11.8% of the 17 patients without previous episodes of UTI had at least one recurrence, while 47.5% of those with previous episodes had at least one recurrence (OR, 6.8; univariate logistic regression). E. coli caused 78% of the recurrent episodes. Phenotypic and genotypic analysis of E. coli strains showed that one-third of the recurrences were caused by the index episode strain, which could persist and cause recurrences throughout the 1-year follow-up period. The prevalence of adhesins or other identified virulence factors for UTI among the recurrence strains was identical to that among the index episode strains. The presence of these factors did not affect the risk of recurrence but did increase the likelihood that the index episode strain would persist and cause recurrent episodes of UTI.

Predominance of class II papG allele of Escherichia coli in pyelonephritis in infants with normal urinary tract anatomy.

P-fimbrial genotypes of Escherichia coli strains and their possible association with urinary tract abnormalities were studied in infants with pyelonephritis. A total of 153 urinary E. coli strains were analyzed by polymerase chain reaction for class I, II, and III alleles of the pyelonephritis-associated adhesin gene papG. Strains with any class II papG alleles were found significantly more often in infants with normal anatomy and function or in infants with clinically insignificant abnormalities than they were in infants with significant abnormalities (90 of 119 vs. 14 of 34 infants; P<. 001). On the other hand, strains without any papG alleles were found significantly more often in infants with major urinary tract abnormalities (11 of 34 vs. 17 of 119 infants; P=.016). Our genotypic findings indicate that, especially in infants with a normal urinary tract, infection is caused by more-virulent E. coli than is present in infants without a normal urinary tract. This virulence could be due to expression of pyelonephritogenic P fimbriae by an infecting E. coli strain.