Bacteriological data on a prospective multicenter study of the effect of two different regimens for selective decontamination in patients with acute leukaemia.

In this paper we described the results of bacteriological monitoring of oropharynx and stool samples from granulocytopenic patients with leukaemia who received oral infection prophylaxis with two different regimens for selective decontamination of the digestive tract. Patients were prospectively randomized either into a group receiving non-absorbable antimicrobial drugs for selective decontamination (polymyxin and neomycin: group A) or into a group receiving polymyxin and co-trimoxazole (group B). The oropharynx was, or became, free of gram-negative bacilli within one week of treatment in 94% and 90%, respectively, of the patients in group A and group B. The stool samples were, or became, negative after the same treatment interval in 91% and 80%, respectively, of the two patient groups. Antibiotic therapy during selective decontamination treatment significantly increased the incidence of positive cultures from the oropharynx and stools. The sensitivity of the gram-negative bacilli isolated during selective decontamination treatment to the drugs administered did not influence the average response to treatment. Both resistant and sensitive gram-negative bacteria appeared to disappear from the patients' samples, mostly within a week, without the need to adjust the selective decontamination treatment. Yeasts behaved in almost the same way as gram-negative bacilli. All patients received oral amphotericin B; some patients occasionally yielded oropharyngeal or faecal cultures which were positive for yeasts.