Glucan, a beta-1,3 polyglucose, was evaluated for its ability to enhance resistance of post-operative mice to experimentally induced C. albicans sepsis. Male C57BL/6J mice were injected i.v. with glucan (0.45 mg/mouse) on days 10,7,4 and 1 prior to midline laparotomy and intravenous challenge with 3 X 10(6) C. albicans. The detrimental effect of surgery on survival following C. albicans infection was manifested by a 47% survival in the non-surgery-infected group in contrast to 20% in the surgery-infected group. Protection against C. albicans was observed in the glucan-treated groups. The glucan-treated non-operated mice manifested 100% survival while the surgery group had a 73% survival. Glucan significantly enhanced macrophage phagocytic function in control and operated mice. Laparotomy alone did not significantly depress macrophage phagocytosis. Histopathological studies revealed that glucan markedly inhibited the renal pathology associated with C. albicans challenge both in the presence and absence of laparotomy. These data indicate that glucan increased survival and reduced renal pathology associated with C. albicans challenge in the post-operative period. These observations suggest that Biologic Response Modifiers such as glucan may be effectively employed in patients who are at risk for post-operative infections.