Synergistic effects of Candida and Escherichia coli on gut barrier function.
BACKGROUND
Disruption of the indigenous gut microflora with overgrowth of gram-negative bacteria and Candida species is common in the critically ill patient. These organisms readily translocate in vitro, which may cause septic complications and organ failure. A synergistic effect between Escherichia coli and C. albicans in polymicrobial infections has been demonstrated. An interaction between these organisms at the mucosal barrier is unknown.


METHODS
Ca(CO2) monolayers were grown to confluence in a two compartment culture system. E. coli and C. albicans or E. coli alone were added to the apical chambers. Secretory immunoglobulin A was added to half of the apical chambers as well. Cell cultures were incubated for a total of 240 minutes. Basal media were sampled at timed intervals for quantitative culture. Monolayer integrity was confirmed by serial measurement of transepithelial electrical resistance.


RESULTS
Secretory immunoglobulin A decreased bacterial translocation across Ca(CO2) monolayers challenged with E. coli alone. Transepithelial passage of E. coli was significantly increased by coculture of bacteria with C. albicans. Augmentation of bacterial translocation by Candida occurred even in the presence of secretory immunoglobulin A.


CONCLUSIONS
Candida colonization of the GI tract may impair mucosal barrier defense against gram-negative bacteria. The clinical role of gut antifungal prophylaxis in protecting against gut derived gram-negative sepsis is speculative.
Diebel
L N
LN
Wayne State University, Detroit, Michigan, USA.
Liberati
D M
DM
Diglio
C A
CA
Dulchavsky
S A
SA
Brown
W J
WJ
D018988:Bacterial Translocation / Q000502:physiology*; D018938:Caco-2 Cells; D002176:Candida albicans / Q000502:physiology*; D002177:Candidiasis / Q000209:etiology / Q000517:prevention & control; D018929:Cell Culture Techniques / Q000379:methods; D015169:Colony Count, Microbial; D016638:Critical Illness; D003428:Cross Infection / Q000209:etiology / Q000517:prevention & control; D003470:Culture Media; D017097:Electric Impedance; D004926:Escherichia coli / Q000502:physiology*; D004927:Escherichia coli Infections / Q000209:etiology / Q000517:prevention & control; D005753:Gastric Mucosa / Q000276:immunology* / Q000382:microbiology*; D006801:Humans; D007071:Immunoglobulin A, Secretory / Q000276:immunology*; D013997:Time Factors
D003470:Culture Media; D007071:Immunoglobulin A, Secretory