Microbiology Flashcards
Which virus does Hepatitis Delta Virus require to be able to be infective?
Hepatitis B because it needs to coat itself with the HBsAg
What cell type mediates the reaction seen on a PPD? Hint: It is the same as contact dermatitis.
T Lymphocyte
What is the clinical presentation of Listeria in adults?
GPR with tumbling motility that causes meningitis in the immunocompromised (ie. transplant recipients). The source is contaminated food.
Which bacteria have a polysaccharide capsule vaccine? How are they administered?
Pneumococcal, HiB, Meningococcal. The polysaccharide is carried by a protein (diphtheria toxin, tetanus toxin or N. Meningitidis outer membrane protein) so it can be presented to T cells.
What are the most serious complications of Amphotericin B?
Renal toxicity that causes hypokalemia and hypomagnesemia.
What are the signs and symptoms of Measles infection?
Cough, Coryza, Conjunctivitis, and Koplik’s Spots
What is the presentation of congenital rubella infections?
PDA, Cataracts and Deafness. Blueberry rash is also possible.
What congenital deficiency can lead to increased risk of mycobacterial infections?
INF (specially gamma) deficiencies.
What are the side effects of protease inhibitors?
Hyperglycemia, Lipodystrophy (Inc. truncal fat, Dec. peripheral) P-450 inhibitors
What is the only DNA hepatitis virus?
Heb B, it’s genome integrates into host genome. It uses a template +RNA for replication.
Which hepatitis virus is most often seen in IV drug users?
Hep C
What is the treatment for toxoplasma?
Sulfadiazine & Pyrimethamine
What is the first line treatment against bacteriodes?
Penicillin G is it has not beta lactamase, if it does use one of the lactmase inhibitor combinations.
What are is the major side effect of Daptomycin?
Myopathy and elevation of Creatine Kinase (CPK)
What are the features of Endotoxin? Particularly Lipid A, found on gram negatives.
Edema Nitric oxide Dic/Death Outer membrane TNF-alpha activator O-antigen eXtremely heat stable IL-1 Neutrophil chemotaxis
What are the two types of toxin that inhibit protein synthesis? Give examples.
Exotoxin A (P. Aeruginosa) and Diphtheria toxin inhibit EF-2. Shiga toxin and Shiga-like toxin remove adenine from 60S rRNA.
Which antibiotic is associated with Serotonin Syndrome?
Linezolid is a slight MOA inhibitor.
Which cranial nerve is most likely injured in an uncial herniation?
CN III
How can you distinguish MAI/MAC from TB?
MAC/MAI grows better at 41C temp.
Which picornavirus cannot colonize the GI because it is acid-labile?
Rhinovirus. All the other ones (Coxsackie A, Echovirus, Polio & HAV) can colonize the GI.
What are the three characteristics of HEV?
Epidemic
Expecting mothers
Enteric
What makes listeria so virulent?
Tumbling motility at 22C. Growth as low as 4C. Listeriolysin O which allow it to escape phagosomes and live intracellularly.
What likely causes loss of vision in HIV patients? What is used to treat it?
CMV can be eradicated with Gancyclovir (first line) & Foscarnet (second line or first line if taking zidovudine)
To what does Strep Viridans bind in order to cause endocarditis?
The bacteria produces dextran from sucrose that they use to bind to fibrin. So valvular damage is required.
What is responsible for the green color of pus on bacterial infections?
Myeloperoxidase. Heme base molecule within the granules of neutrophils that catalyzes the synthesis of HOCl for respiratory burst.
Describe the initial presentation of acute HBV infection.
Serum-sickness like illness. (malaise, fever, urticaria, pruritus, LAD and joint pain) The ALT and AST elevation come after.
What is the treatment for S. Epidermidis infection of devices?
Vancomycin plus either Rifampin or Gentamicin or both.
Which viral families have segmented genomes?
"BORA is a bunch of little islands." Bunyavirus = 3 circular ss(-)RNA Orthomyxovirus = 8 linear ss(-)RNA Reovirus = 10 to 12 linear dsDNA Arenavirus = 2 circular ss(-)RNA
What is the post-exposure prophylaxis treatment for N. Meningitidis?
Rifampin
What electrolyte abnormality can be caused by Legionella?
Hyponatremia
Which HIV viral gene is most closely related to HAART resistance?
Mutations in pol can give resistance to either protease inhibitors or reverse transcriptase inhibitors.
Roseola versus Rubella?
Roseola is caused by HHV-6 and the maculopapular rash starts at the trunk and moves to the head. Rubella has LAD and the rash moves in the opposite direction.
What virulence factor allows E Coli to invade?
K-1 capsular antigen. Allows it to cause neonatal meningitis.
What allows S. Epidermidis to create biofilms?
Quorum sensing induces synthesis of an extracellular polysaccharide matrix.
What histological finding is useful for distinguishing Tropheruma Whippelii?
Deep pink PAS stain of the Glycoprotein Cell Wall. Unlike Glycogen it is Diastase resistant which makes it even more pink than collagen on PAS.
Which bacteria is the most commonly transmitted via deco-oral route from animals to humans in industrialized countries?
Campylobacter. (Puppies, Cattle or contaminated food) Remember the association with Guillain-Barré Syndrome.
What vaccine contains Polyribosyl-ribitol-phosphate (PRP)?
HiB
What are the catalase positive organisms that are commonly seen in Chronic Granulomatous Disease?
Staph A. Pseudomonas Serratia Nocardia Aspergillus
What is a CNS disease that presents YEARS after apparent recovery from a Measles virus infection?
Subacute Sclerosing Encephalitis
What is the complication caused by accidental spilling of contents of a hydatid (Echinococcus) cyst?
Anaphylactic Shock
Which cytokine is responsible for septic shock?
TNF-alpha
Which type of immunodeficiency allows candida infections to become systemic?
Neutropenia. While loss of CD4+ T Cells from HIV can give you thrush or candidiasis it is loss of neutrophils that can turn it into an invasive infection. (ie. Right Sided Endocarditis, Liver or Kidney abscess, Candidemia)
What disease can Parvovirus B19 cause on a healthy adult?
Arthritis
What are the first anti-psudomonals that should come to mind?
Piperacillin, Ticarcillin, Ceftazidime, Cefepime and much later ciporfloxacin, levofloxacin, or carbapenems
What infection in children can be improved by Vitamin A supplementation?
Measles
How do bacteria gain aminoglycoside resistance?
Plasmids that code for proteins that change the drug chemically. Acetyl Adenyl or Phosphate.
What are the notable toga viruses?
Rubella
EEE
WEE
Dermatologic findings in Syphilis by stage.
Primary = Painless Chancre Secondary = Macular rash of palms and soles plus condylomata lata. Latent = Nothing Tertiary = Gumma
