Nosocomial bloodstream infections caused by gentamicin-resistant gram-negative bacilli

Gentamicin resistance has emerged since 1971 among gram-negative bacilli isolated at the University of Virginia Hospital. Of 9,169 gram-negative bacilli isolated in 1971, 0.8 per cent were resistant to gentamicin by disc sensitivity testing. Of 7,817 isolates in 1975, 7.7 per cent were resistant. Approximately 20 per cent of the Klebsiellae had a minimum inhibitory concentration (MIC) ≥ 16 μg/ml of gentamicin.