Lecture 12: Infection Types Part 1

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What is the difference between Neisseria meningitidis and Neisseria gonorrhoeae?

CO2 requirement for growth

Type of sugar in the cell wall

Ability to survive outside the human host

Presence of a capsule (correct)

How are Neisseria gonorrhoeae typically transmitted?

Through contact with an infected animal

Through person-to-person contact (correct)

Through contaminated food and water

Through respiratory droplets

What type of molecule does Neisseria gonorrhoeae have instead of LPS?

Teichoic acid

Lipo-oligosaccharide (correct)

Capsular polysaccharide

Peptidoglycan

What is the result of phylogenetic analysis of Neisseria meningitidis and Neisseria gonorrhoeae?

They evolved from a common ancestor but colonized distinct ecological niches Signup and view all the answers

What is unique about Neisseria gonorrhoeae's survival outside the human host?

It does not survive well outside the human host Signup and view all the answers

What is the significance of N. lactamica?

It is a commensal strain Signup and view all the answers

What is the main function of the neisserial Opa proteins?

Mediate binding to CD4+ T lymphocytes Signup and view all the answers

What is the frequency of phase variation in Neisseria gonorrhoeae?

1/1000 generations Signup and view all the answers

How many different opa genes can be present in a single chromosome of Neisseria gonorrhoeae?

Up to 11 different opa genes Signup and view all the answers

What is the result of out-of-frame repeats in the Opa gene?

No protein is made Signup and view all the answers

What is the mechanism of antigenic variation in Neisseria gonorrhoeae?

Homologous recombination Signup and view all the answers

What is the purpose of the repeat sequence CTTCT?

Signal cleavage Signup and view all the answers

What is the likely outcome if bacteria penetrate across the endothelium and spread through the bloodstream?

Disseminated gonococcal or meningococcal infections Signup and view all the answers

What is the consequence of the genetic strategies employed by Neisseria?

Hyper-variability of surface antigens Signup and view all the answers

What is the function of the Opa proteins in Neisseria?

Evasion of immune response Signup and view all the answers

How many different antigenic variants of pili can a bacterium have?

1 million Signup and view all the answers

What is the mechanism of Opa antigenic variation?

Slipped strand synthesis Signup and view all the answers

What is the purpose of Neisseria's hyper-variability of surface antigens?

Evasion of immune response Signup and view all the answers

What is the most common type of plague?

Bubonic Plague Signup and view all the answers

Which type of plague is characterized by the infection of the lungs?

Pneumonic Plague Signup and view all the answers

What is the primary method of diagnosing plague?

Symptom presentation Signup and view all the answers

Which antibiotic is commonly used to treat plague?

Streptomycin Signup and view all the answers

What is a common symptom of Bubonic plague?

Swollen and tender lymph glands Signup and view all the answers

What is often administered to individuals who have been exposed to plague?

Antibiotics Signup and view all the answers

What is the result of homologous recombination between pilE and pilS genes?

Multiple variations of pilin genes are produced Signup and view all the answers

What is the function of the two distinct extracellular IgA1 proteases produced by N.gonorrhoeae?

Cleave human antibodies Signup and view all the answers

Why are N.gonorrhoeae exclusively human pathogens?

Because they can bind to human transferrin and lactoferrin Signup and view all the answers

What is the function of sialic acid in N.gonorrhoeae?

It sialylates the oligosaccharide component of LOS, making the organism serum-resistant Signup and view all the answers

What is unique about the iron acquisition mechanism of N.gonorrhoeae?

They are highly efficient at utilizing transferrin-bound iron Signup and view all the answers

What is the term for the ability of N.gonorrhoeae to change its antigenic properties?

Opa antigenic variation Signup and view all the answers