To distinguish the relative importance of the oxidative branch of the pentose phosphate pathway from the non-oxidative transaldolase-containing branch, a mutant in phophogluconolactonate (gnd) and a mutant defective in gluconate catabolism, 6-phosphoglyconate dehydrase (edd), were tested in competitive infections with the parental CFT073 wild-type strain. This evidence concerns the gene UBR5 and infection.