11/5 HL 6 Exam 3

Check-in with LSU ID card to confirm identity at the exam location.
Pre-registration for exams is crucial. Late registration may lead to inability to secure a spot, especially notable for Heinz Hall.
Suggestion to borrow a dry erase board from the testing center.
- Useful for visually organizing thoughts and solving problems, especially when managing a large number of questions (e.g., 50 questions).

Review the animated lecture topics posted.
Pay special attention to handouts and notes given during lectures.
- Ensure understanding of material to aid in exam preparation.
- Links to information sources provided in handouts for further reading.

All key terms should be noted for study purposes.
- Importance of writing everything on the board emphasized, as these terms are crucial for understanding.

Three practice quizzes available as preparation tools.
Class will not meet next week to allow everyone time to prepare for Exam 3.
One lowest exam score from Exams 1, 2, or 3 will be dropped to benefit students' final grades.
Breakdown of grades:
- Lecture exam weighs 45% of total grade.
- Up to six lowest quiz scores can be dropped from your total.
- Final exam is mandatory and scheduled after Thanksgiving.

Register early for the final exam at Heinz Hall, adhering to specified rules (e.g., no cell phones).
Rules against wearing watches due to potential for cheating must be observed.

Current average for the class is 82%.
- No curve applied as the percentage does not warrant adjustments.
- Strong performance across the class noted, with many students scoring above 80%.

Discussion of top five bacterial pathogens and their mechanisms for infection scheduled.
Emphasis on understanding actual viral and bacterial behavior, including details on how they affect human cells.
Future topics will include the nitrogen and carbon cycles, highlighting the positive role of bacteria in these systems.

Concept of opportunistic pathogens discussed,
- Example: Gradient problem with common pathogens like E. Coli and Staphylococcus aureus.
- Discussion around when the body’s immune system might fail, citing scenarios like stress, malnutrition, and lack of probiotics.

Proteus mirabilis as an opportunistic pathogen, particularly significant in hospital settings.
- Can lead to urinary tract infections, especially in post-operative patients with catheters.
- Importance of catheter hygiene stressed to prevent infection.

Initial Attachment
- Bacteria secrete a non-sticky protein to bind onto catheter surfaces, even in the presence of mannose (sugar).
- Mannose is known to prevent bacteria from sticking; however, Proteus mirabilis can effectively attach despite it.
Shape Manipulation
- Bacteria elongate and filament out, enhancing attachment strength through increased surface area.
- Stronger attachment creates persistence, making it hard to dislodge.
Production of Urease
- Proteus mirabilis secretes urease that converts urea into ammonia, thus raising the pH of urine.
- A higher pH can precipitate calcium and magnesium salts.
Crystal Formation
- Rising pH leads to the formation of crystals (calcium and magnesium phosphates) from body fluids, creating a habitat for bacteria to grow.
Colonization and Biofilm Development
- Increased bacterial colonization leads to blocking of catheter and further compounding the problem.
Hyperflagellation
- Once blocked, bacteria can develop additional flagella to propel themselves upstream into the urethra.
- This stage indicates a key pathogenic action that can result in serious infection.

Importance of catheter sanitation and monitoring for urinary tract infections.
Recognition of immune system vulnerabilities, particularly in high-stress periods such as exams.

Understand the behaviors and mechanisms of opportunistic pathogens like Proteus mirabilis.
Recognize the shifts in environmental aspects concerning human health due to bacterial presence.
Establish a firm grasp on basic microbiological terminologies and their clinical implications.

Anticipate lectures surrounding remaining topics post-exam and their recording for home study.
Further consolidation of microbiological knowledge with emphasis on understanding pathogenicity and mechanisms of various bacteria and diseases they cause.