B-210. Genomic Comparison of Urease-Producing Enterobacteriaceae Isolated from Catheterized Patients Presenting with Urinary Tract Infection

E. L. Flannery1, H. L. T. Mobley2;
1Sch. of Pub. Hlth., Univ. of Michigan, Ann Arbor, MI, 2Univ. of Michigan Med. Sch., Ann Arbor, MI.

Urinary tract infections (UTIs) occur in up to 60% of women in their lifetime and nearly all catheterized patients. Although community-acquired UTIs are primarily caused by Escherichia coli, the prevalence of etiologic agents of catheter associated UTIs (caUTIs) differs. CaUTIs are the most common hospital acquired infection and emergence of antibiotic resistance is apparent. They are caused by a variety of uropathogenic gram-negative bacteria including E. coli, Enterococci spp., Klebsiella spp, Morganella morganii, Proteus mirabilis, P. vulgaris, Providencia stuartii and Pseudomonas aeruginosa. Prevalence of these bacteria in causing caUTI ranges from 10-42%, with P. mirabilis predominating as the most common etiologic agent. P. mirabilis, P. stuartii and M. morganii are of particular interest because they are the only urease-producing Enterobacteriaceae and mixed species colonization of catheters with these organisms occurs frequently. The roles of E. coli and P. mirabilis in UTI have been extensively studied yet M. morganii and P. stuartii have been less characterized despite their significant contribution to caUTI. Comparative genomic hybridizations (CGHs) were performed to identify conserved genes between these uropathogens that could explain their role in infection and disease. Genomic DNA from P. mirabilis HI4320, P. stuartii BE2467 and M. morganii TA43 was labeled with Cy3 or Cy5 fluorophores and hybridized to a microarray containing 70-mer oligonucleotide probes representing 3719 ORFs of P. mirabilis HI4320. CGHs revealed 312 and 473 genes conserved between HI4320 and BE2467 and HI4320 and TA43, respectively. Specifically, a 100kb putative pathogenicity island containing virulence genes encoding for antibiotic resistance, iron acquisition and adherence, was present in all three uropathogens. Surprisingly, only a small subset of genes is highly conserved among these closely-related bacteria. The location of one-third of these genes in a putative pathogenicity island with an increased GC content suggests the importance of these genes in virulence and likelihood that they were acquired by horizontal gene transfer.

128/B. Microbial Interactions with Phagocytes

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