Candida albicans translocation across the gut mucosa following burn injury

Normal guinea pigs were challenged intragastrically with Candida albicans 1 hr prior to a 30 or 50% flame burn to determine if burn injury increased translocation of the yeasts across gut mucosa. Tissues were harvested between 3 and 24 hr postburn and cultured on Sabouraud dextrose agar. Control animals (no yeast challenge) showed no yeast in intestinal homogenates or in the mesenteric lymph nodes (MLN). At a dose of 1 × 10 9 yeasts, they did not escape from the gut lumen, with either a 30 or 50% burn. At a dose of 2 to 4 × 10 10 organisms, they translocated to the MLN in 92% of the 50%-burned animals ( P < 0.001), 75% of the 30%-burned animals ( P < 0.05), and 12.5% of unburned animals. The ileal mucosa appeared to be the most susceptible site for yeast invasion. To observe the penetration through the gut mucosa and/or translocation to other tissues, yeasts were labeled with biotin before administration, and tissues were stained with avidin-peroxidase diaminobenzidine sequence. With biotinylated yeasts, phagocytized organisms were observed in large numbers in the lamina propria and mesenteric lymph nodes but they were not viable upon culture. Toluidine blue staining of semithin sections revealed that translocated yeasts were located selectively in the lymphoid follicles of the MLN, entrapped by macrophages.