Enhancement by Candida albicans of Staphylococcus aureus, Serratia marcescens, and Streptococcus faecalis in the establishment of infection in mice

Abstract

Candida albicans has been shown to stimulate infection in mice by a number of bacteria. Mice inoculated intraperitoneally with as little as 500 colony-forming units of Staphylococcus aureus along with a nonlethal dose of 108 colony-forming units of C. albicans (one-third the dose causing 50% mortality in 7 days) developed widespread staphylococcal infection. S. aureus injected alone at that or considerably higher doses did not establish infection. Phage typing methods demonstrated that the staphylococcal infection was due to the bacterial organisms originally injected. A minimum dose of C. albicans between 1.1 x 105 and 1.1 x 107 colony-forming units was necessary for the amplification of virulence of S. aureus to take place. Serratia marcescens and Streptococcus faecalis inoculated intraperitoneally at small nonlethal doses could also be recovered from blood and tissues 5 days after animals were dually injected with C. albicans but not from animals which were inoculated with the same amounts of these bacteria alone.