Survey of antibiotic susceptibility among gram-negative bacilli at a cancer hospital.

A survey was conducted of the susceptibility of gram-negative bacilli to selected broad-spectrum antibiotics. The organisms were isolated from all patient specimens submitted to the routine microbiology laboratory during two three-month periods. Overall, the least resistance was observed against imipenem and ciprofloxacin. Considering all of the gram-negative bacilli, differences in susceptibilities to the other antibiotics (aztreonam, cefoperazone, ceftazidime, piperacillin) were minimal. Significant increases in resistance to some antibiotics occurred during the latter period.