MP77-16 PHENOTYPIC VIRULENCE TRAITS, PHYLOGENETIC GROUPING AND PREVALENCE OF PATHOGENICITY ISLAND MARKERS GENES IN ESCHERICHIA COLI ISOLATES FROM PATIENTS WITH ORTHOTOPIC ILEAL NEOBLADDER

Abstract

INTRODUCTION AND OBJECTIVE:The malX gene was identified in uropathogenic Escherichia coli (UPEC) strain CFT073 as part of a pathogenicity-associated island about 20 years ago. Homology analysis indicated that it is a component of the phosphotransferase system (PTS) of carbohydrate transport. We compiled the evidence that correlates malX to UTIs. To determine its function, which is unknown, we constructed and characterized mutants lacking malX.METHODS: We compiled all published information about the presence of malX in UPEC strains. We constructed a mutant with a deletion of malX in the model UPEC strain UTI89 and characterized its growth and carbohydrate depletion.RESULTS: A PubMed search identified 8 papers that surveyed a correlation between malX and urinary tract infections. A compilation of these results showed that malX generally correlates with UTIs and phylogenetic group B2 which is the most common UPEC group. The malX gene associated with UPEC strains is only 40% identical to the previously described malX which means that the malX designation for the UPEC gene is incorrect. We provisionally designated the virulence factor gene as malX2. A malX2 mutant grew poorly in medium in which glucose, xylose, and glycerol were the sole carbon sources. The mutant depleted carbohydrates slowly.CONCLUSIONS: The MalX2 protein appears to be the major transporter for several carbohydrates. A previous study of nonpathogenic E. coli proposed that the original MalX (not MalX2) transported carbohydrates by facilitated diffusion. If this is also true for MalX2, then such transport, which is potentially rapid, may in part account for rapid growth of UPEC strains. This novel transport system distinguishes uropathogenic from nonpathogenic E. coli.