Occurrence of gram-negative non-fermenting rods in hemocultures and their sensitivity to antimicrobial agents

In the period from January 1993 to June 1996 were at the Department of Microbiology of the University Hospital in Olomouc 122 strains of Gram-negative nonfermentative rod-shaped bacteria isolated from haemocultures. The majority represented the group of 51 strains of the genus Acinetobacter (41.8%), complex A. calcoaceticus-baumannii (Acb complex). The second largest group were 21 strains (17.2%) of Pseudomonas aeruginosa. These were followed by 17 strains (13.9%) of Stenotrophomonas maltophilia, 8 strains (6.6%) of non-Acb complex acinetobacters, 6 strains (4.9%) of Pseudomonas putida and 5 strains (4.1%) of Alcaligenes xylosoxidans. The remaining species were represented only by 1-2 strains. In three isolations was the identification impossible. The majority of strains (24.6%) were from the Department of Haematology of the University Hospital in Olomouc. The most frequent diagnoses in patients with positive haemocultures were leukemias and lymphomas (24.6%). The most effective tested antimicrobial agents were ceftazidime (93.4% of sensitive strains) and ofloxacin (91.7%). From the total number of 80 strains detected using the equipment BacT/Alert 120, 22 (27.5%) were isolated repeatedly confirming their role in the etiology of bacteriemic or septic episodes. Because only one blood sample was obtained in 34 cases (58.6%) of the remaining 58 only once detected strains, it was impossible to confirm their etiologic role by repeated isolation. (Tab. 6, Ref. 22.)