Question

Case Study: You are a nurse in the Intensive Care Unit at Plessy Hospital in Chicago, IL where several of your patients are mechanically ventilated. You are made aware that many of the units’ patients have developed high fever and their leukocyte count is higher than normal, thus you fear a widespread nosocomial pneumonia infection. You must determine what bacteria your patients are infected with, how they should be treated, and describe what preventive measures should be implemented, if any.

Use these number 1-4 to answer the case study with at least 250 words

1. Introduction: Introduce your particular case study and explain what it is. Please hypothesize which microorganism you believe may be involved, backing your rationale using primary literature.

2. Methods: Please refer to the provided dichotomous key and identify a minimum of five techniques that can be used to identify the unknown microorganism. Briefly indicate the significance of each technique and what it tells us on a biochemical or molecular level (You will go into more detail about the significance of each test in the discussion section). Also be sure to include practical details of how you would perform this test in a laboratory.

3. Results: List the tests in the order that you would perform them. Be sure to indicate the expected result for the bacteria that you hypothesized. For example, if you choose E. coli, you would start by indicating that a Gram stain was performed and that you were able to identify Gram negative rods. Use a photo of Gram stained E. coli obtained online and cite your source. Do this with each of the 5+ tests that you believe will help you identify the unknown.

4. Discussion: You will want to go into detail about the significance of each test performed and how it helped you arrive at your conclusion. For example, if you chose a fermentation test, talk about the significance of a microbe being able to metabolize X compound and what caused the indicator dye to change colors.  You will also want to discuss possible treatments for your scenario. When writing, remember that we want you to demonstrate that your rationale is based on science and not a lucky guess. Remember to add plenty primary sources and include many in-text citations.

Answer 1

Introduction

​​​​​​Patients on mechanical ventilation develops fever and high leucocytes. This indicates infection. Nosocomial infection is associated with ventilator patients. The causative organism is strptococcus pneumoniae. Patients develop VENTILATION ASSOCIATED PNEUMONIA (VAP) which is the common nosocomial infection.

In ventilated patients bacteria gain easy access to lower respiratory tract because

• Endotracheal tube prevents reflexes like cough.
• Frequent aspiration of fluids from mouth to trachea.
• Normal Flora get destructed because of prolonged ventilation.
• Immunosuppression because of medications.

Methods and results

• gram stain - identifies gram positive cocci.
• Catalase - negative catalase test indicates presence of strptococcus.
• Optochin test - susceptibility to optochin indicates presence of strptococcus.
• Bile solubility test - it's a confirmatory test for s.pneumoniae. s.pneumoniae is bile soluble and it differentiate this organism from other strptococcus organism.
• Bacterial isolate culture. - isolates from endotracheal tube and respiratory tract cultured to identify presence of organism.

Discussion

• gram stain help to identify whether the causative organism is gram positive or negative.
• Catalase is a enzyme that breaks down H2O2 into H2O and O2. Presence of bubble in medium indicates positive test. It helps to identify which gram positive cocci is present.
• Optochin test - pneumoniae strains are sensitive to the chemical optochin (ethylhydrocupreine hydrochloride).
  Optochin sensitivity allows for the presumptive identification of alpha-hemolytic streptococci as
  S. pneumoniae, although some pneumococcal strains are optochin-resistant. Other alpha-
  hemolytic streptococcal species are optochin-resistant.
• Bile solubility test - sodium dioxycholate will lyse the bacterial wall and makes it soluble. It's specific for s pneumoniae. Other strptococcus strains are bile insoluble.
• Bacterial culture - the isolates from tube and tract are incubated and PCR test done to identify the presence. The organism in the isolate are grown in favorable conditions and presence is tested.

prevention

follow VAP bundle

• Elevate head end 35-40 degrees.
• Daily sedation vacation

Non invasive positive pressure ventilation

Re intubation

Early tracheostomy