[Microbiological findings of 97 cases of acute pyelonephritis]

To optimize the therapeutic approach to acute pyelonephritis (PNA), the medical records of 89 patients (73 women and 16 men) hospitalized with diagnosis of PNA between January 1984 and 1987 have been studied. According to routine bacteriological urinalysis, gram-negatives were found in more than 92% (E. coli in 79%, Proteus in 6%). Gram-positives were found in only 8%. The gram-negatives (n = 82) showed resistance to amoxicillin in 36%, to amoxicillin/clavulanic acid in 17%, to cotrimoxazole in 18%, and to ceftriaxone in 1%. No resistance to netilmicin or norfloxacin was found. These results justify treatment with norfloxacin or ceftriaxone instead of amoxicillin, amoxicillin/clavulanic acid or cotrimoxazole for gram-negatives. Among the 7 cases with gram-positives, resistance was found to amoxicillin/clavulanic acid, cotrimoxazole and also netilmicin, and to norfloxacin, ceftriaxone and amoxicillin. Therefore, an initial therapy using the association amoxicillin-netilmicin is recommended in PNA.