Question

Outbreak on a Cruise ship! Your job is to think about the results and to use the information to make a recommendation to the Cruise line. How can they best get rid of the problem? Part 1-Legionnaire's Disease 1) What causes Legionnaire's Disease? Briefly describe the lifestyle of the pathogen involved in this disease. Why is it such a problem on cruise ships? (2 points) Part II - Sampling the Environment 2A) The Direct Fluorescent Antibody (DFA) Assay was used to find the pathogen in ship samples. Explain how this method works, as used to detect this pathogen. (2 points) 2B) Which of the WATER samples were positive for the pathogen? Which of the SWABBED samples were positive? Did the positive samples look different from the control? Why or why not? (2 pts) Part III - Your Experimental Results 3) You went into the lab to try your own set of experiments. Briefly describe the set up and the results you got (2 points) You may find it convenient to put your results in the chart below. The controll has been completed for you. CONTROL CHLORINE HEAT + CHLORINE UV RADIATION OZONE OZONEK CHLORINE Part IV: Your Conclusion Based on your results, which one treatment do you recommend? recommendation must include why you think that treatment the best option IN THIS CASE, compared to the others. You must refer to the results and include background information from the references as needed. (2 points)

Answer 1

1) Legionnaires disease is caused by a bacteria named Legionella.

• A person gets this disease by breathing the droplets of water present in air that contain this Legionella bacteria.  
• Legionella bacteria - gram negative aerobic rod shaped bacteria, that can act as intracellular parasites on eukaryotic cells.
• Legionella bacteria enter the human body by inhaling mist of water $\rightarrow$ It reaches alveoli of lungs $\rightarrow$ They are engulfed by macrophages $\rightarrow$ the bacteria converts macrophage into specialised membrane bound compartment rather than engulfing $\rightarrow$ start multiplication

Such a problem is appearing in cruise ships because:-

Legionella containing vacuoles surrounded by vesicles from ER Vacuoles vacate their contents into LCV Phagocytosis LCV surrounded like ER like membrane LCV starts to receive contents of lysosomes Infectious form of Legionella Infectious Legionella produced

• Members in cruise ship is almost always exposed to water.
• Legionella can grow bestly in warm waters as seen in hot tubs in these cruise ships.