Proteomics in the Study of Bacterial Keratitis

Abstract

Bacterial keratitis is a serious ocular infection that can cause severe visual loss if treatment is not initiated at an early stage. It is most commonly caused by Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pneumoniae, or Serratia species. Depending on the invading organism, bacterial keratitis can progress rapidly, leading to corneal destruction and potential blindness. Common risk factors for bacterial keratitis include contact lens wear, ocular trauma, ocular surface disease, ocular surgery, lid deformity, chronic use of topical steroids, contaminated ocular medications or solutions, and systemic immunosuppression. The pathogenesis of bacterial keratitis, which depends on the bacterium-host interaction and the virulence of the invading bacterium, is complicated and not completely understood. This review highlights some of the proteomic technologies that have been used to identify virulence factors and the host response to infections of bacterial keratitis in order to understand the disease process and develop improved methods of diagnosis and treatment. Although work in this field is not abundant, proteomic technologies have provided valuable information toward our current knowledge of bacterial keratitis. More studies using global proteomic approaches are warranted because it is an important tool to identify novel targets for intervention and prevention of corneal damage caused by these virulent microorganisms.

Challenges of corneal infections

“…As of 2014, there are 40.9 million contact lens wearers over 18 years of age in the USA, accounting for 1 million visits to health care professionals for keratitis, at an estimated cost of $175 million [33]. The species of the invading organism and the virulence factors they utilize determines the pathogenesis of the infection [34]. …”

“…Patients with keratitis often present with one or more symptoms including eye pain, decreased vision, redness, or tearing [34]. Treatment with a fortified antibiotic (cefazolin 5% and tobramycin or gentamicin 1.4%) [45] is often initiated prior to receiving results of bacterial smears or cultures.…”

Comparative analysis of the tear protein profile in herpes simplex virus type 1 epithelial keratitis

“…Therefore, changes in tear protein composition can directly reflect the physiological and pathological state of the eye tissue [ 9 ]. High-throughput proteomics technology provides a comprehensive analysis of the tear proteome and can be used as a screening method for ocular diseases such as dry eye disease [ 10 , 11 ], bacterial keratitis [ 12 ], fungal keratitis [ 13 , 14 ], diabetic retinopathy [ 15 , 16 ], and thyroid-associated eye disease [ 17 ]; systemic diseases like breast cancer [ 18 , 19 ] and neurological disorders [ 20 ]; and for discovering potential new therapeutic targets for these clinical situations. Therefore, studying the characterization of proteomic changes associated with HSV-1 epithelial keratitis will help to elucidate its pathogenesis, and further identify the therapeutic targets of disease.…”

A Review of the Cytokine IL-17 in Ocular Surface and Corneal Disease

“…(7,32) Similar to other bacterial infections, the pathogenesis of bacterial keratitis (caused primarily by extracellular bacteria) is dependent on the species of the bacteria, the virulence factors and host immune response. (33) Heimer et al (Table 1) investigated the gene expression of human corneal epithelial cells secondary to infection with Staphylococcus aureus. The study found that of the inflammatory mediators assessed (IL-1β, IL-2, IL-4, IL-10, TNF-ɑ, CSF-2, IL-6, IL-8, IL-17 and IFN-γ) in epithelial cells, IL-6, IL-8, IL-17 and IFN-γ showed the greatest expression rate.…”