Acute Pyelonephritis

Enterococcal aggregation substance and binding substance are not major contributors to urinary tract colonization by Enterococcus faecalis in a mouse model of ascending unobstructed urinary tract infection

Isogenic Enterococcus faecalis strains that differ in their expression of aggregation substance (AS) and its cognate receptor, enterococcal binding substance (EBS), were compared for urovirulence in mice. Strain OG1SSp/pCF500 (inducible AS(+), constitutive EBS(+)) failed to outcompete isogenic derivative INY3000 (AS(-) EBS(-)) in the urine, bladders, or kidneys of mice harvested at 48 h postinoculation. Neither mouse nor human urine induced AS expression by OG1SSp/pCF500. Recombinant strain OG1SSp/pINY1801 (constitutive AS(+), EBS(+)) exhibited plasmid segregation that was as extensive in vivo as in vitro. These data suggest that AS and EBS do not contribute to upper or lower urinary tract colonization by E. faecalis and that growth in urine does not induce AS expression by strains carrying plasmids in the pCF10 family.

Fever in the clinical diagnosis of acute pyelonephritis

Acute pyelonephritis is a clinical syndrome that can be confused with other conditions. To investigate this problem, a retrospective cohort study was conducted using two mutually exclusive sets of clinical criteria for acute pyelonephritis in women 15 years of age or older who presented to the emergency department of a university hospital. All patients had pyuria, and one group had documented fever (temperature of > or = 37.8 degrees C) while the other group had a temperature of < 37.8 degrees C but had other evidence of possible upper tract infection. The study cohort was comprised of 103 febrile and 201 afebrile patients. Afebrile hospitalized patients were ultimately found to have another diagnosis more often than were the febrile hospitalized patients (35% v 7%; P = .02), and the afebrile nonhospitalized patients were more likely to have another diagnosis than were the febrile nonhospitalized patients (13% v 0%; P = .004). Other diagnoses included cholecystitis, pelvic inflammatory disease, and diverticulitis. The positive predictive value of the definition of pyelonephritis in the febrile group was 0.98, and it was 0.84 for the afebrile group. Physicians examining patients with clinical evidence of acute pyelonephritis but without objective fever should be alert for alternative diagnoses.

Effectiveness of cefetamet pivoxil in the treatment of pyelonephritis in children

Cefetamet pivoxil was investigated in an open, randomized comparative study involving a total of 37 children with acute pyelonephritis, whose ages ranged from 2 to 14 years. The patients received either 10 mg/kg (n = 18) or 20 mg/kg (n = 8) cefetamet pivoxil twice daily, or 30-50 mg/kg amoxycillin/clavulanic acid three times daily (n = 11) for a period of 7-10 days. Escherichia coli was the main causative agent isolated in 28 (75.7%) of the patients; other pathogens included Proteus mirabilis (three patients). Proteus species (one patient), Klebsiella pneumoniae (two patients), Pseudomonas diminuta (one patient) and mixed infections (three patients). No differences in the overall treatment outcome could be observed between the treatment regimens used and, at the end of treatment, all pathogens were eradicated with neither relapse, nor persistence of the isolated pathogen, nor reinfection occurring. The clinical signs and symptoms had subsided in all patients at treatment end and the tolerability of the trial drugs was found to be satisfactory with no premature treatment withdrawal required. It is concluded that cefetamet pivoxil in the standard twice-daily dose of 10 mg/kg was equally effective and as well tolerated as 20 mg/kg cefetamet pivoxil given twice daily or 30-50 mg/kg amoxycillin/clavulanic acid given three times daily.

Acute pyelonephritis. Preventing complications through prompt diagnosis and proper therapy

The diagnosis of pyelonephritis is based on clinical and laboratory criteria that include fever, flank pain or tenderness, leukocytosis, pyuria, and confirmatory urine culture. A Gram stain of unspun urine can provide an important early clue regarding the etiologic agent. At least 85% of cases are caused by Escherichia coli, but clinicians need to be aware of other potentially aggressive organisms as well. Elderly, diabetic, or immunocompromised hospitalized patients and patients subject to instrumentation present a more complex diagnostic challenge and require more intense parenteral treatment. Prompt diagnosis and proper therapy decrease the risk of serious complications.