Jornal de Farmacogenômica e Farmacoproteômica

Abstrato

Virulence Factors of Gram negative Bacteria Related to Ocular Infections

Panagiota Xaplanteri

Many Gram-negative bacteria have been implicated in ocular infections causing severe vision impairment. The aim of this study is to list the virulence factors of the main gram-negative ocular pathogens. Data were extracted from PubMed and Google Scholar. Virulence factors of N. gonorrhoeae: pili, opacity proteins, lipooligosaccharide, sialylation, outer membrane porin PorB, IgA extracellular proteases, reduction modifiable protein. Virulence factors of Pseudomonas aeruginosa: Slime-glycolipoprotein, flagella, type IV pili, Quorum Sensing in biofilms. Virulence factors of Chlamydia trachomatis: The inoculation of the bacterium triggers an outburst of inflammatory response in the conjunctiva. The result is the replacement of the loose Type I stromal collagen of the area by compact Type V collagen that leads to trachomatous scarring of conjunctiva and severe vision impairment. Virulence factors of Bartonella Species: Bartonella targets and enters in the CD34+ cells, mainly erythrocytes and endothelial cells, where it survives in a vacuole protected from host defense mechanisms. The first step of pathogenesis is proinflammatory and autocrine activation and proliferation of the endothelial cell, which leads to inhibition of apoptosis. The second step is paracrine activation of macrophages and epithelial cells. Other virulence factors are the outer membrane proteins, TFSS transport systems, and the LPS which is atypical. It is a weak stimulus and antagonizes Toll Like Receptor 4. Gram negative bacteria provoke direct tissue damage and interact mainly with components of the innate immunity. The outcome of the battle is abolishment of the blood-ocular barrier and enhanced recruitment of inflammatory cells. For biofilm forming bacteria like P. aeruginosa, comprehension of their communication, survival and attack of host tissues is always a challenge. The enlightenment of the mechanisms of infection caused by these pathogens is crucial in diagnosis and treatment as they remain major causes of vision impairment.