Changes in the oral microflora in patients with acute leukemia and related disorders during the period of induction therapy.

The present study reports changes occurring within the oral microflora in 20 patients with leukemia during and after the period of high-dose cytotoxic therapy. The relationship between the presence of enterobacteria, yeast cells, and staphylococci and the occurrence of oral ulcers/angular cheilitis was also studied. To make a comparison, three groups of patients without malignant disorders (acute disorders, long-term hospitalization, antibiotic treatment) were also studied. The total number of salivary microorganisms remained unchanged during the period. Fourteen of twenty patients with leukemia harbored enterobacteria on at least one occasion. No differences were found in the number of enterobacteria before, during, and after treatment with cytotoxic or antimicrobial drugs. Enterobacteria were also found in the reference group with long-term hospitalization, but seldom in the other reference groups. Staphylococci and lactobacilli were present in all patients in the leukemia group and in the majority in the reference groups. Yeast cells were found in 80% of the patients with leukemia. Patients with ulcers and/or angular cheilitis had higher numbers of yeast cells than the other patients. There was no relationship between enterobacteria or staphylococci and oral lesions.