Escherichia coli ESBL positive and its interaction with the human urothelial cells - Dissertation Example

The gene encoding the antibiotic resistance is found on plasmids, transposons, and inserted in genes in bacteria all over the world and in multiple species. Although much research has been conducted to characterize the microbial enzyme biochemically, PCR analysis remains the “gold standard (4, 5, 6).” E. coli isolates from the environment are generally succeptible to beta-lactam antibiotics because of the absence of a strong promoter sequence for the expression of the gene for Beta-Lactamase.

However, extensive use of antibiotics and the spread of genetic elements among the bacteria have resulted in development of Beta-lactam resistant strains. Consequently, Beta-lactam resistant strains of E. coli have been isolated from hospitals and clinics around the world (7, 8, 9). Klebsiella is a member of the Enterobacteria that is a small, non-motile rod, and the bacterium is often associated with urinary tract infections. Klebsiella is capable of nonaerobic metabolism and is found in water and soil, in addition to the mammalian intestinal and urinary tracts.

Klebsiella possesses the enzyme nitrogenase, and is capable of nitrogen fixation under nonaerobic conditions, but the bacterium loses this capability under the aerobic environment in mammalian intestinal and urinary tracts (1, 10, 11, 12). Aims and Objectives The binding of E.coli to urothelial cells is mediated by pili via the FIMH protein. The receptor for the binding has been elucidated to be uroplakin 1a in mouse cells (13). Mutation of key residues in FIMH attenuates binging of E.coli to the FIMH urinary receptor and consequently reduces colonization of the bacteria in the bladder.

The binding is mediated by mannose residues and relies on a key pocket in the FIMH protein (14, 15). Isolates of E. coli from a septic lamb were utilized to characterize the cytotoxic necrotizing factor type 2, and it was discovered that this protein enters effected epithelial cells and targets Rho protein, which subsequently reorganizes actin filaments into stress fibers in the effected host cells (16, 17, 18). Photodynamic therapy (PDT) has been utilized to treat many epidermal conditions in humans.

These include skin cancer, acne, skin rejuvination, hidradenitis suppurativa, psoriasis, cutaneous T-cell lymphoma, disseminated actinic porokeratosis, localized scleroderma, and vulval lichen sclerosis. Other applications include anal and vulvar carcinoma, palliation of metastatic breast cancer to skin, Barrett’s esophagus, and retinal macular degeneration (19, 20, 21). PDT is characterized by the application of moderate light (50mW/s) for a moderate amount of time (15 minutes) to the infected area which creates a photosensitization period followed by a destruction period.

PDT application results in a 5 to 6 log decrease in infectious, antiobiotic resistant bacteria by destruction of amino acids and polylysine tracts present in bacterial proteins, as well as the creation of destructive reactive oxygen species (22, 23, 24). It is proposed in this work that PDT be utilized to irradiate E. coli and Klebsiella beta-lactamase positive bacteria from cultures of human urothelial cells. Materials and Methods Human urothelial ce