Septicemia in patients with hematological disorders and neutropenia. A retrospective study of causative agents and their resistance profile.

In order to identify the cause of septicemia and the resistance patterns of bacteria in Swedish patients with hematological disorders, all positive blood cultures collected at a hematological ward during 1980-1986 were evaluated retrospectively. 198 episodes of septicemia in 129 patients were recorded. 54% were males and 46% women with a median age of 67 years (range 16-88). Patients with acute leukemia (46%), lymphoma (19%) and myeloma (19%) dominated. The absolute neutrophil count (ANC) was less than 0.5 x 10(9)/l in 76% of the bacteremic episodes. A total of 253 consecutive isolates were found with 53% Gram-negatives and 47% Gram-positives. The dominating pathogens were Escherichia coli (27%), klebsiella/enterobacter (15%), pseudomonas (7%), coagulase negative staphylococci (13%), alpha-streptococci (13%), Staphylococcus aureus (10%) and anaerobes (6%). Coagulase negative staphylococci showed a significant increase in isolation rate during the study period. The majority of E. coli were resistant to ampicillin. The susceptibility of klebsiella/enterobacter to ceftazidime and cefuroxime was reduced, while no imipenem resistant strains occurred. Among coagulase negative staphylococci 61% were resistant to isoxazolylpenicillin, none to vancomycin. No dramatic changes in the etiology of septicemia or the susceptibility pattern during the study period were noticed. Coagulase negative staphylococci, S. epidermidis in particular, constitute an increasing problem among granulocytopenic patients.