Quiz 3 Select Agents

Question 1

Bacillus anthracis

Answer 1

Anthrax. Gram positive rod. Spore forming. Found in livestock historically. Spores are inhaled to alveoli, macrophages ingest and transports spores to lymph nodes, and that is where they grow. Main toxin leads to edema, necrosis, and hemorrhage. Inhalational - fever, chills, mediastinal adenopathy, meningitis. Cutaneous - papules, ulcerations, pruritic, black eschar with edema. Gastrointestinal - eating undercooked meat with spores, fever, vomiting, nausea, ulceration in GI. Injection - IV heroin use.

Question 2

Clostridium botulinum

Answer 2

Botulism. Gram positive rod, anaerobic. Secretes a paralytic neurotoxin. Spore-forming. Found in canned vegetables, honey, peyote, fish. Associated with black-tar heroin use. Intestinal and inhalational are most common. Bilateral cranial neuropathies, symmetrical descending weakness and paralysis, nausea, dry mouth, diarrhea, autonomic problems.

Question 3

Yersinia pestis

Answer 3

Plague. Gram negative rod, anaerobe. Safety pin look on gram stain. From bites of fleas to animals to us. Bubonic - lymphadenopathy in armpit, smooth oval mass, most commonly femoral lymph nodes. Septicemic - GI symptoms, hemorrhage rash and gangrene. Pneumonic - fever, dyspnea, watery and purulent bloody sputum. Can be passed via respiratory droplets. Multilobar consolidation.

Question 4

Francisella tularensis

Answer 4

Tularemia. Gram negative intracellular pathogen. Replicates in macrophages, similar to Bacillus anthracis. In mammals, ticks, birds, and rabbits. Called rabbit fever. Passed through direct contact with them. Not person to person. Six disease forms. Ulceroglandular - ulcers, lymphadenopathy. Glandular - lymphadenopathy. Oculoglandular - conjunctiva infection, lymphadenopathy. Oropharyngeal - undercooked mammal meat, pharyngitis, diarrhea, abdominal pain. Typhoidal - septicemia and no lymphadenopathy or ulcer. Pulmonary - inhalation of aerosol, spread through bloodstream.

Question 5

What are the 3 major bacterial pathogens for meningitis? And other key characteristics about meningitis?

Answer 5

1) S. pneumonia (Gram positive diplococci)
2) Neisseria meningitidis (Gram negative diplococci)
3) Listeria monocytogenes (Gram positive rod)
- The bacterial factors that aid in meningeal invasion include fimbriae, association with monocytes, platelet-activating factors, pneumococcal choline-binding protein A. Their capsule helps them colonize in mucosal areas, survive intravascularly, and survive in subarachnoid space.
- Newborns - GBS, E. Coli, Listeria
- Kids - S. pneumo, N. meningitidis, H. influenza
- Adults - S. pneumo, N. meningitidis
- Elderly - S. pneumo, N. meningitidis, aerobic gram negative rod (pseudomonas)
- Basilar skull fracture (bugs from throat) - S. pneumo, H. influenza, GAS
- Head trauma - S. aureus, coag neg staph
- Viral meningitis - Enterovirus (most common cause of aseptic meningitis and summer virus), as well as HSV (type II). Enterovirus causes rash as well, and leaves within a week.
- Encephalitis - HSV (type I) - May be associated with primary infection or reactivation, Fever, headache, seizures, vomiting, psychiatric issues. CSF has less cells. You get a gyriform enhancement in the temporal lobes, usually asymmetric. You get hemorrhaging and edema in brain as well.
- Normal Meningitis presents as headache, stiff neck, eye pain with light, altered mental status.
- Meningococcal meningitis - usually caused by N. meningitidis, get rash, especially if asplenic. CSF flowing out of nose, ear. Water-house Friderichsen syndrome.
- Fungi are chronic cause of meningitis.
- With CSF stats, Viral will have high glucose and bacterial and mycobacterium will both have low glucose. Bacterial will have high neutrophils and myco and viruses will have low neutrophils. All will have elevated proteins.

Question 6

What is malignant organism that causes Malaria? Benign organisms? Other malaria facts.

Answer 6

Malignant - Plasmodium falciparum. (can affect ALL red blood cells, also has malaria toxin that triggers cytokine storm, also hides out on vessel walls to avoid spleen and to replicate and clog vessels with its knobs, also switching knobs through antigenic variation)
Benign - Plasmodium vivax, ovalae, and malariae. (can affect only young RBC’s like reticulocytes)
-These bugs enter skin, enter liver and hepatocytes, release into bloodstream, enter erythrocytes and lyse them.
-HRP2 is a protein that is secreted from these bugs and it is how we detect malaria.
-Clinical presentations of malaria include coma (microvasculature obstruction in brain), acidosis (blocking microvasculature, downstream tissue can’t get its oxygen), and anemia (red cells are destroyed and lysed).