Molecular Epidemiologic Identification of Escherichia coli Genes That Are Potentially Involved in Movement of the Organism from the Intestinal Tract to the Vagina and Bladder

Abstract

A first step in urinary tract infection (UTI) pathogenesis in the otherwise healthy host is the movement of uropathogenic Escherichia coli from the intestinal tract to the urinary tract. We conducted a genomic subtraction to isolate genetic regions associated with this movement. A representative UTI isolate present in the rectum, vagina, and bladder of a woman with UTI was chosen as the tester; the driver was a phylogenetically distant rectal isolate (based on pulsed-field gel electrophoresis analysis) with a profile of uropathogenic virulence genes similar to that of the tester. Tester-specific regions identified by the subtraction were screened, using DNA dot blot hybridization, against a collection of 88 uropathogens isolated from the rectum, urine, and/or vagina of women with UTIs and 54 E. coli isolates from the same women that were found only in the rectum. Twelve genetic regions occurred more often in multisite isolates than in rectal site-only isolates. Eleven of these 12 genetic regions are homologous to regions in the sequenced uropathogenic E. coli CFT073 strain.

Identification of New Genetic Regions More Prevalent in Nontypeable Haemophilus influenzae Otitis Media Strains than in Throat Strains

“…A commercial subtractive hybridization kit (PCR-select; Clontech, Palo Alto, Calif.) was used to identify gene fragments specific to the tester strain through differential cloning by previously described methods (37,55).…”

Probe Hybridization Array Typing: a Binary Typing Method for Escherichia coli

“…A consensus sequence was obtained for each of the seven gene The number of rectal isolates in which the prevalence of different gene fragments was determined. sLZ-, sJX-, sRB-, and sSU-prefixed gene fragments were derived from different genomic subtraction experiments that are published elsewhere (4,23,28,30). fragments in 33 strains of E. coli.…”

“…These genomic subtraction experiments yielded sPCR fragments that were either uniquely present in a greater number of pathogenic UTI strains or more likely to be involved in shared strains between heterosexual partners or shared between bladder, vaginal, and rectal sites. The details of these subtractions are described elsewhere (3,23,28,30,32). sPCR fragments were cloned into commercial vectors (TOPO; Invitrogen, Inc.) and probed for presence or absence in UTI and non-UTI E. coli collections.…”

Management of sexually active teenagers with initial symptoms of vaginal disbiosis

“…Конечно, способность к перемеще-нию из прямой кишки присуща не только отдельным штаммам лактобацилл, но и другим микроорганиз-мам желудочно-кишечного тракта, имеющим специ-фический вагинальный тропизм [17]. Молекулярно-генетическими исследованиями установлено, что в геноме уропатогенного штамма E. coli присутствует новый регион, определяющий его способность к распространению из кишечника во влагалище и мо-чевой пузырь [18]. Единственным хорошо изучен-ным штаммом лактобацилл является штамм L. rhamnosus GG [19].…”