Effect of ceftriaxone on the outcome of murine pyelonephritis caused by extended-spectrum-ß-lactamase-producing Escherichia coli.

Urinary tract infections (UTIs) due to extended-spectrum-ß-lactamase (ESBL)-producing Enterobacteriaceae in children are becoming more frequent, and they are commonly treated initially with a second- or third-generation cephalosporin. We developed a murine model of ascending UTI caused by ESBL-producing Escherichia coli. Using this model, we investigated the renal bacterial burden, interleukin-6 (IL-6) expression, and histopathological alterations caused by ESBL- and non-ESBL-producing bacteria after 1, 2, or 6 days with or without ceftriaxone therapy. The renal bacterial burden, IL-6 concentration, and histological inflammatory lesions were not significantly different between mice infected with ESBL- and non-ESBL-producing bacteria without treatment at any of the time points examined. Following ceftriaxone administration, the bacterial burden was eliminated in the kidneys of mice infected with ESBL- and non-ESBL-producing bacteria on the 6th postinfection day. The histological analysis demonstrated that among mice treated with ceftriaxone, those infected with ESBL-producing bacteria had more profound renal alterations than those infected with non-ESBL-producing bacteria on the 6th day (P < 0.001). In comparison, microbiological outcomes did not differ significantly between mice infected with ESBL- and non-ESBL-producing bacteria at any of the time points examined. The effectiveness of ceftriaxone in mice with UTIs due to ESBL-producing E. coli may have therapeutic implications; it is, however, hampered by limited activity on the histopathological lesions, a finding that needs further investigation.

Renal abscess due to Pseudomonas aeruginosa: report of two cases.

We report two cases of renal abscess due to Pseudomonas aeruginosa in previously healthy children. The first patient was a nine-year old girl with a three-week history of intermittent fever and the second was a three-year old boy with a four-day history of fever. Pseudomonas aeruginosa was isolated from the urine cultures of both children. In both cases ultrasound and CT/MRI scans revealed the formation of a renal abscess. The patients were successfully treated with administration of antipseudomonal drugs for seven and five weeks, respectively. In both children no surgical intervention was required and the follow-up revealed no impact on the overall renal function or arterial pressure.

Percutaneous ultrasound-guided renal biopsy in children: a single centre experience.

BACKGROUND AND AIM: The contribution of renal biopsy is of major importance in many renal diseases in children. In our study we aimed to evaluate retrospectively the indications, safety, efficacy and the spectrum of histopathological findings of percutaneous ultrasound-guided renal (PRB) biopsy during a 7 year period as well as to analyze specific groups of renal patients. PATIENTS AND METHODS: A total of 84 renal biopsies were performed in 81 children. Demographic data, clinical symptoms at presentation, indications for renal biopsy, laboratory findings, complications of the procedure and histological diagnosis were obtained from all patients who underwent PRB. RESULTS: The commonest indication for biopsy accounted was steroid resistant, steroid dependent or frequent relapsing idiopathic nephrotic syndrome (INS). Subcapsular hematoma presented 11% of the patients, but none of them needed blood transfusion. Adequate renal tissue sample was obtained in 97.7% of the renal biopsies. In 80% the histopathology revealed glomerular diseases. The most frequent types of biopsy-proven renal diseases were: focal segmental glomerulosclerosis (FSGS) (15%), IgA nephropathy (13.5%), minimal change disease (10%), various stages of lupus nephritis (8.5%), Henoch-Schonlein nephritis (7.5%), membranous glomerulonephritis (7.5%), mesangioproliferative glomerulonephritis (6%), post-infectious glomerulonephritis (6%), hemolytic uremic syndrome (5%), tubulointerstitial nephropathies (3.5%), acute tubular necrosis 2.5%. Among the 28 cases of INS, FSGS accounted for 43%. The leading histopathological pattern found in patients with recurrent episodes of gross haematuria was IgAN (84.5%). Among 7 cases of lupus nephritis, the observed histological types were: IV+V in 3/7, IIIA in 3/7 (43%) and IIB in 1/7. CONCLUSIONS: Our study shows that percutaneous ultrasound-guided renal biopsy is a safe, reliable and effective technique in children. It also provides updated information for childhood renal disease pattern.

Hemolytic uremic syndrome and thymic dysplasia in an infant.

A 33-day-old male infant was admitted to the neonatal intensive care nursery because of respiratory distress, grunting, cyanosis, and radiological findings of bilateral bronchopneumonia. He responded well to intensive therapy, but 11 days later developed hemolytic uremic syndrome, which was treated conservatively with prednisone and plasma transfusions with good response. The hemolytic uremic syndrome resolved, but he subsequently developed severe recurrent infections of unknown etiology and died at the age of 78 days. Necropsy findings revealed necrotizing enterocolitis as well as dysplasia of the thymus and other lymphoid tissues, compatible with the diagnosis of immunodeficiency disorder.