BACKGROUND:Opportunistic infection of Candida albicans(C.albicans) has become a serious problem in immunocompromised patients.The study aimed to explore the mechanism of enterogenous infection of C.albicans in immunocompromised rats under severe acute pancreatitis(SAP).METHODS:Sprague Dawley(SD) rats(n=100) were randomly assigned into 5 groups as the following:blank group,cyclophosphamide+ceftriaxone+SAP group,cyclophosphamide+ceftriaxone group,cyclophosphamide+SAP group,and cyclophosphamide group.The rats were sacrificed at 5and 10 days,and their jejunum,colon,mesenteric lymph nodes,pancreas,intestinal content,and blood were quickly collected to detect C.albicans.A region of the 25 S rRNA gene was chosen and amplified by polymerase chain reaction(PCR) to differentiate C.albicans genotypes.The amplified products were further sequenced and compared to judge their homology.RESULTS:Compared with the Cyclophosphamide group,the combination of immunosuppressants and broad-spectrum antibiotics significantly increased the colonization of C.albicans in intestine in 5 and 10 days.Pure SAP stress did not increase the opportunistic infection of C.albicans.The PCR products of C.albicans isolates all belonged to the genotype A family,and sequence alignment showed that the amplified fragments were homologous.CONCLUSION:The damage of immune system and broad-spectrum antimicrobial agents are important risk factors for opportunistic fungal infection.Intestinal tract is an important source for genotype-A C.albicans to translocate and invade into bloodstream. BACKGROUND: Opportunistic infection of Candida albicans (C. albicans) has become a serious problem in immunocompromised patients. The study aimed to explore the mechanism of enterogenous infection of C. albicans in immunocompromised rats under severe acute pancreatitis (SAP). METHODS: Sprague Dawley (SD) rats (n = 100) were randomly assigned into 5 groups as the following: blank group, cyclophosphamide + ceftriaxone + SAP group, cyclophosphamide + ceftriaxone group, cyclophosphamide + SAP group, and cyclophosphamide group. These rats were sacrificed at 5 and 10 days, and their jejunum, colon, mesenteric lymph nodes, pancreas, intestinal content, and blood were quickly collected to detect C. albicans. A region of the 25 S rRNA gene was chosen and amplified by polymerase chain reaction (PCR) to differentiate C .albicans genotypes. The amplified products were further sequenced and compared to judge their homology .RESULTS: Compared with the Cyclophosphamide group, the combination of immunosuppressants and broad-spectrum antibiotic s significantly increased the colonization of C. albicans in intestine in 5 and 10 days. Pure SAP stress did not increase the opportunistic infection of C. albicans. PCR products of C. albicans isolates all belonged to the genotype A family, and sequence alignment showed that the amplified fragments were homologous. CONCLUSION: The damage of immune system and broad-spectrum antimicrobial agents are important risk factors for opportunistic fungal infection. recess tract is an important source for genotype-A C. albicans to translocate and invade into bloodstream.