Antibiotics
Complement System
Innate v. Adaptive
Bugs
Clinical Vignettes
100

These four drugs are used to treat Mycobacterium tuberculosis infection.

Rifampin (RIF), Isoniazid (INH), Pyrazinamide (PZA), and Ethambutol (EMB)

100

These are the 3 main pathways of complement activation.

Classical pathway, lectin pathway, and alternative pathway

100

The innate immune system is the body’s first line of defense. Which of the following cells is primarily first cell involved in phagocytosis and acts quickly to respond to pathogens in this early immune response?

Neutrophils

100

Gram (+) bacteria that is also catalase (+) and coagulase (+) and produces a toxin that causes RBC lysis and cause vomiting and diarrhea

  • Staphylococcus aureus

    • alpha-toxin = cause beta-hemolysis

    • enterotoxin = food poisoning

100

Patient recently underwent endotracheal intubation and now presents with a fever of 102.4 and right sided jaw pain. Labs show elevated amylase but normal lipase. What is the diagnosis and probable bacterial agent?

Parotitis; Staph A. 



200


This IV antibiotic when administered too rapidly results in the patient developing hypotension, as well as marked flushing & itching over the upper portion of his chest, neck and face.



Vancomycin



200

This component, also known as C3 convertase, plays a key role in the alternative pathway activation of the complement system.

C3bBb

200

An 8-year-old girl eats a cookie and minutes later develops hives and difficulty breathing. Which cells are most likely to be mediating this reaction?

Mast cells



200

circular dsDNA virus that is associated with human cervical cancer by inhibition of p53 and Rb via oncoproteins E6 and E7 respectively

HPV = human papillomavirus

200

Patient presents with fever, AMS, neck rigidity. ROS + for headache, n/v. Labs remarkable for low glucose and high protein in CSF studies. What is the diagnosis and likely etiology?

Bacterial Meningitis, Strep Pneumo

300

This antibiotic is used to treat Clostridium difficile infections and can cause neurotoxicity, confusion, and suprainfections.

Metronidazole (Flagyl)

300

This component of the complement system is responsible for neutrophil chemotaxis.

C5a

300

In response to a bacterial infection, B cells are activated and begin producing antibodies specific to the bacterial antigens. Through what process do these B cells improve the binding affinity of their antibodies for the antigen during subsequent infections?

somatic hypermutation 

300

Virus that replicates in CD21 cells and causes infectious mononucleosis

Epstein Barr virus

300

Patient presenting with progressive difficulty with walking and now decreased truncal control along with tingling in extremities. PE remarkable for decreased strength in bilateral LE along with absent DTRs. HX remarkable for episodes of diarrhea 2 weeks ago that resolved spontaneously. What is the diagnosis and agent?

GBS secondary to Campylobacter



400

To which antibiotic is this bacterial culture most sensitive based on disc diffusion assay?


Antibiotic A

400

This test is used to screen for the activation of the classical complement pathway.

CH50 test



400

A 34-year-old woman presents with recurrent upper respiratory infections. Laboratory results show normal immunoglobulin levels, but further testing reveals a lack of isotype switching. Which T cell-derived cytokine is essential for B cell class-switching to IgG and IgE, and is likely deficient in this patient?



IL-4

400

Gram (-) bacteria that is catalase (+) and coagulase (-) that produces an A:B toxin

Escherichia coli

400

5 month old female presents from pediatrician to due concerns of decreased PO intake, wakefulness, and activity. Mom reports symptoms started over the past 24 hours with baby unable to hold head up and now is unable to reach with hands. Physical exam is notable for flaccid paralysis and absent DTRS. What is the diagnosis and agent?



Botulism, Clostridium botulinum 

500

These four antibiotics/classes are characterized by their requirement for a minimum peak concentration to achieve optimal efficacy.

Aminoglycosides (e.g., gentamicin, tobramycin, amikacin), Fluoroquinolones (e.g., ciprofloxacin, levofloxacin, moxifloxacin), Daptomycin, Metronidazole



500

A terminal complement deficiency (C5-C9) increases susceptibility to recurrent infections by this bacterial species.

Neisseria

500

A researcher isolates naïve T cells from a healthy individual and observes that these cells require two signals for full activation. Signal one is antigen recognition via the T cell receptor (TCR). Which molecule on the antigen-presenting cell (APC) provides the critical second signal, binding to CD28 on the T cell to promote T cell activation and proliferation?

B7 (CD80/CD86)



500

an endoparasite transmitted via kissing bugs and can cause heart arrhythmia if left untreated

Chagas disease (Trypanosoma cruzi)

500

Patient is a 16 YOF presenting with a 6 month history of productive cough with reddish sputum, night sweats, and fevers. Physical exam is notable for a 15 pound weight loss since 1 year ago with lymphadenopathy and spinal tenderness. What is the etiology?



TB