Disk diffusion test. Strain of Klebsiella pneumoniae isolated from a patient with urinary tract infection. On Mueller-Hinton
agar, cultivation 37°C, 24 hours. Good susceptibility to all tested antibiotics, except for ampicillin (left on the top).
Klebsiella pneumoniae is inherently resistant to ampicillin, amoxicillin and ticarcillin (constitutive production of
beta-lactamases). Notice individual colonies of Klebsiella pneumoniae growing in the zone of inhibition around
ampicillin disk.