The bacteria can survive on skin are normally gram-positive because of their ability to survive in dry and humid conditions. The conditions on the skin are not suitable to all bacteria such as gram-negative bacteria and only those that can survive salty and dry conditions can survive. The skin has defense mechanism against pathogens such as its low moisture level, acidity, rigidity and defenses released by the skin.
Certain areas of our body do contain gram-negative bacteria, staphylococcus aures and corynebacterium. Those areas are the armpit, groin and toe webbing because it is a moist area, however the bulk of human skin contains gram-positive bacteria such as staphylooccus epidermis and propionobacterium. Siegenthaler, D. and Siegenthaler, S. (2009), You’re Skin-Home to Millions of Microorganisms, Retrieved from http://www. ellsphere. com/skin-beauty-article/your-skin-home-to-millions-of-micro-organisms/582120 Someone who is immunocompromised means they have an immune system that has been impaired due to a disease or a certain treatment. The eye structure is the most direct way for exposer from the environmental bacteria to enter causing infections and certain diseases.
Immunocompromised hosts are more likely to get an eye infection caused by fungi because the immune response is generally very effective at controlling fungal infections, therefore it will eliminate pathogenic fungi when they begin to grow in the body and cause diseases. However an individual who is immunocompromised the fungi on the inside or the outside colonize leaving them with lower levels of fungi that exists as a commensal in the body which can outgrow and cause a disease, unfettered by the immune response.