EVALUATING CHILDREN IN THE UKRAINE FOR COLONIZATION WITH THE INTESTINAL BACTERIUM OXALOBACTER-FORMIGENES, USING A POLYMERASE CHAIN REACTION-BASED DETECTION SYSTEM

Background: Oxalobacter formigenes is a recently discovered anaerobic bacterium residing in the gastrointestinal tracts of most vertebrates, including humans, Evidence suggests that this bacterium plays an impo rtant symbiotic relationship with its hosts by regulating oxalic acid homeostasis. Oxalic acid is a ubiquitous toxic by-product of metabolis m associated with numerous pathologic conditions, including hyperoxalu ria, cardiac myopathy and conductance disorders, kidney stones, and ev en death. Despite the potential importance of O. formigenes in several major health disorders, the difficulty in culturing, isolating, and i dentifying this fastidious anaerobe has limited research of its diseas e associations, Because O. formigenes must use two unique enzymes to c atabolize oxalic acid, this bacterium appeared to be a suitable model for DNA-based identification, thereby circumventing the labor-intensiv e procedures currently used. Methods and Results: In this study, genus -and group-specific oligonucleotide sequences were designed correspond ing to homologous regions residing in the ore gene that enodes for oxa lyl-coenzyme A decarboxylase. A polymerase chain reaction (PCR)based a mplification of the 5' end of this gene directly from genomic DNA isol ated from various strains of O. formigenes was used to show that the g enus-and group-specific oligonucleotide probes could identify and subg roup the bacterium. Field testing of this PCR-based detection system w ith 100 fecal cultures collected from children aged 0-12 years demonst rated the ease and efficacy with which O. formigenes can now be identi fied. Furthermore, these latter data provide a profile for the natural colonization of a human population with this intestinal bacterium. Co nclusions: Development and use of this PCR-based detection system perm it the rapid identification and classification of the gut-associated b acterium O, formigenes, thereby circumventing the need for the more la bor-intensive and lengthy method currently used. The first field test of this detection system indicates that humans apparently do not becom e colonized with O. formigenes until they begin crawling about in the environment. Furthermore, studies investigating the association betwee n several disorders leg, kidney stones, irritable bowel syndrome, and hyperoxaluria) and the absence of the bacterium from the gut will now prove far easier.