Antibiotic susceptibility of periurethral anaerobic microflora in healthy girls.

The in vitro susceptibility of sixty-four isolates of periurethral anaerobic bacteria to nine commonly used antibiotics was analyzed. Using a quantitative sampling method, the three predominant anaerobic strains were isolated from each periurethral sample of twenty-one healthy prepubertal girls. The majority of strains showed high sensitivity to ampicillin and phenoxymethylpenicillin, whereas trimethoprim and trimethoprim--sulfamethoxazole showed no or only slight inhibition of growth of most strains. Intermediate sensitivity was found to erythromycin, cefuroxime, pivmecillinam, norfloxacin and nitrofurantoin. Our data suggest that several antibiotics used in paediatric praxis might influence the indigenous periurethral anaerobic microflora. Hypothetically, this may be a factor of importance in the pathogenesis of ascending urinary tract infections.

Accuracy of ultrasonic assessment of residual urine in children.

Bladder volumes were determined by realtime ultrasonography and compared to catheterised volumes in a consecutive series of 101 children. Volumes were calculated as the product of the longitudinal, transversal and sagittal diameter and a correction factor of 0.52. There was a good correlation between the methods (r = 0.96) although large volumes tended to be underestimated by ultrasonography. Small volumes could be assessed accurately.

Single dose treatment of cystitis in children.

The efficacy of single dose treatment with trimethoprim compared to a 5-day course with the same drug was investigated in 100 children, 3-12 years, with isolated episodes of symptomatic non-febrile urinary tract infection. Cure, defined as sterile urine during the first week after treatment, was achieved in 74% (37/50) in the single dose group compared to 86% (43/50) in the 5-day treatment group. The difference was not statistically significant (chi 2 = 2.25, p = 0.134 two-tailed). The cure rates in relation to P-fimbriation of the infecting E. coli strains were similar in the two groups. During the 6 month follow-up, six children in each treatment group had one or more reinfections. Extended studies are needed to conclude if single dose and conventional treatment courses are equally effective.

Changes in periurethral microflora after antimicrobial drugs.

The periurethral flora was examined in 18 girls by use of a quantitative sampling method before, during, and three weeks after treatment with antibiotics for upper respiratory tract infections. Eight girls received amoxicillin. In five of them the anaerobic flora showed a reduction in total counts and in numbers of different species, and all eight girls got a heavy colonisation with enterobacteria during treatment. Three weeks after treatment the anaerobic and aerobic flora had reversed to the pretreatment composition. In 10 girls treated with trimethoprim-sulphamethoxazole the anaerobic flora remained unaffected and no enterobacterial overgrowth was registered during the study period. We propose that antibiotics could be one among several factors involved in the pathogenesis of urinary tract infection, by suppression of the anaerobic microflora and promotion of the colonisation with enterobacteria.

Residual urine in children with acute cystitis and in healthy children: assessment by sonography.

Residual urine was assessed by ultrasound in children with single attacks of symptomatic lower urinary tract infection and in healthy controls. Residual urine was found significantly more often in the 39 patients during acute illness as well as during a follow-up of 6 months, compared to 55 control children. Infections caused by P-fimbriated Escherichia coli were not more often associated with residual urine than infections with nonP-fimbriated Escherichia coli or other bacterial species. It is suggested that residual urine is a facilitating host factor among others in the pathogenesis of symptomatic urinary tract infection in childhood.

Antenatal renal pelvis dilatation emphasizing vesicoureteric reflux: two-year follow-up of minor postnatal dilatation.

AIM: To describe the occurrence of foetal renal pelvis dilatation in an unselected population of pregnancies and to describe the clinical course in a subgroup of infants with minor renal pelvis dilatation (RPD). METHODS: During 1996-1999 the foetuses of 17850 consecutive pregnant women were scanned with ultrasonography (USG) in the 16th-19th gestational week and later in the pregnancy when indicated. RPD was defined as anterior-posterior pelvic diameter > or = 5 mm. After birth all infants were examined with USG twice. If any postnatal USG showed RPD > or = 10 mm, extended radiological investigation was performed. Infants with pelvis dilatation < 10 mm and no calyceal or ureteric dilatation were not investigated further and antibiotic prophylaxis was discontinued. The children were followed up at 2 y of age. RESULTS: 109 foetuses (0.6%) with RPD were identified. Postnatally, 94/109 were available for follow-up: 43 had postnatal dilatation > or = 10 mm and were investigated and treated according to clinical routine, while 51 had dilatation < 10 mm and were followed up after they had reached at least 2 y of age. No case of pyelonephritis was recorded. USG in 48/51 children was normal. CONCLUSION: The data indicate that infants with minor RPD do not constitute a risk group for renal morbidity and thus do not need antibiotic prophylaxis and extensive radiological examination.

P-fimbriated Escherichia coli in children with acute cystitis.

P-fimbriation of Escherichia coli is an important factor in the pathogenesis of childhood pyelonephritis. The present study investigates children with single episodes of symptomatic non-febrile urinary tract infection, i.e. cystitis, with respect to clinical appearance and bacteriology, especially the frequency of P-fimbriated E. coli. The study included 75 children, 57 of whom had their first attack of urinary tract infection. E. coli was the causative agent in 88% (66/75) of the infections, and 48% (32/66) of E. coli strains were P-fimbriated. No association was found between identification of P-fimbriated E. coli at index infection and proneness to reinfection during the following six-month period. It is suggested that P-fimbriated E. coli is a virulence factor even in lower urinary tract infections, when occurring in single, symptomatic episodes.