Focusing on microbiology
While the title of this post suggests a focus on microbiology, disciplines in medical science are so intricately woven together, it is hard to define one specific topic without touching its relevance in other fields.
If you ever worked or visited large hospitals, you’d know what I am talking about. Imagine a cancer patient. Because he/she often received large dosage of radiation or chemo-therapy, there is a general lack of strong immune system, giving plenty opportunities for bacteria infections. Also, the late over-use of anti-microbial agents have resulted in massive development of antibiotic-resistant bacteria IN or AROUND hospitals. One common germ we find around us (even as we speak now) is a bug call Staphylococcus aureus. Staphylococcus for it’s round shape and aureus for it’s golden color. It’s usually harmlessly living in the nose or skin of a healthy person (remember that first hand-shake?? hehehe). Complications arise when the skin-barrier has been broken, which allows the bacteria to sneak in and attack. S. aureus can cause a wide range of infections from common pimples to pneumonia etc. Also, this bug could withstand hydrogen peroxide and form blood clots!! So your normal Sav-on/Long’s drug H2O2 would have no effect here. Even worst, an immuno-suppressed person who is more susceptible to bacterial infection often resides within the hospital where antibiotic-resistant S. aureus may likely to share the same residence! Giving medications (antibiotics) without knowing what strains of the bug a patient may have often accelerates the infection and exacerbates the condition.
Recently, a "crystal structure" of a critical enzyme called Extracellular Fibrinogen -binding protein (Efb-C), produced S. aureus was solved, meaning we now know what this enzyme "looks" like, thus could infer how it may function. This enzyme helps the bug evade our common defense against the microbial community, called the complement system. The complement system is basically a set of reactions (cascade) that generates a large sticky ball around the bug, engulfing and neutralizing it (them). Efb-C basically blocks this cascade from occurring, thus rendering our primary defense useless. Once the crystal structure of Efb-C is solved, we could design novel small molecules to target this protein, thus creating a NEW kind of antibiotic! 
Let’s now go back to the hospital scenario. Once a person has been identified of carrying antibiotic resistant S. aureus, we could administer this new drug and save the patient from potentially life-threatening complications (meningitis, Pneumonia etc). What’s the moral of the story? um… wash your hands and stop touching yourself the whole day. Oh yeah, for those internet cafe goers, wipe the keyboard and mouse or wash your hands after an evening of CS or Doom!
Credit: Michal Hammel, Georgia Sfyroera, Daniel Ricklin, Paola Magotti, John D Lambris, Brian V Geisbrecht Nature Immunology
8, 430 - 437
(01 Apr 2007)
