Practice Exam 1 Qs Flashcards
What is the only genus of G- cocci that frequently cause disease?
Neisseria sp.
This bacteria is non motile, aerobic but can grow anaerobically, is positive for catalase and oxidase, and humans are the only reservoir.
Neisseria
This is Neissera sp. is nonencapsulated, with strong adhesions, please/antigenic variation, and found on the genitals?
N. Gonorrhoeae
True or false. Minigitidis is encapsulated with endotoxins and hemolysins.
True
How are gonococci internalized?
Parasite directed endocytosis
True or false. Gonococci utilize glucose, but not sucrose or maltose?
True
True or false meningococci utilizes both glucose and maltose
True
Why are vaccines to gonococci difficult to produce?
Due to antigenic phase variation they change too often due to this strong virulence factor, there IS a vaccine to meningococci however.
I am a small, aerobic, gram - coccobacilli which colonizes the upper respiratory tract of almost all humans, is non type able, non encapsulated.
Haemophillus influenza
Which influenza is most virulent?
Hib - H. Influenza type b (causes bacteremia and meningitis in children less than 2, facial cellulitis, epilottitis, bronchitis, pneumonia
What does H. Influenza need for growth and why?
Lysed blood chocolate agar - requires hemin (x factor) and NAD+ (v factor) for growth
I am a gram - bacilli, motile, found in soil/water/soap/lotion, cause swimmers ear and hot tub rash.
Pseudomonas aeruginosa
All other strains EXCEPT haemophilus only require what for growth?
ONLY NAD+ Blood agar - not chocolate agar
Where does pseudomonas aeruginosa get its carbon and nitrogen from?
Acetate and ammonia, readily available in most environments (easy requirements)
Mucoid polysaccharide capsule, siderophores, elastase, exotoxin a, phospholipase c are all ________ types of virulence factors in psudomonas?
Persistence virulence factors (collagenase, flagella and heat stable hemolysins are all part of dissemination (spread) virulence factors).
True or false, pseudomonas generally adheres well to healthy epithelium?
False - they are opportunistic and take advantage of cuts and immunosuppresed/compromised hosts
What is the endotoxin in pseudomonas?
LPS - which interacts with TLR4 to initiate host inflammatory response - fever hypotension, gram - sepsis
What cleaves elastin and collagen to cause direct tissue damage, cleaves proteinase inhibitors and cleaves complement and immunoglobulins?
Elastase - multifunctional protease (elastase cleaves elastin - similar names)
When cystic fibrosis respiratory cells bind more P. Aeruginosa, why does this happen and what are the results?
Cystic fibrosis transmembrane conductance regulator (CFTR) gene is dysfunctional due to genetic mutation causing 1. The loss of Cl - transport, 2. Dehydration of respiratory secretions resulting in thick mucous. Basically there is a gene for CF and peoples lungs fill with mucous.
What is characterized by severe systemic illness due to organ malfunction?
Sepsis, this is NOT the same as bacteremia
How does pseudomonas D.C. abuse sepsis?
Due to microbial products interacting with host lymphatic cells
What is the best method of treating pseudomonas?
Antibiotic synergism
What are populations or communities of micro organisms adhering to a surface?
Biofilm
What is the true phenotype of most bacteria?
Encased in extra cellular glycoproteins and polysaccharide (glycocalyx)
Which bacteria are important in biofilms and quorum sensing?
P. Aeruginosa
I am strictly anaerobic, gram positive rod, produces endospores, are resistant to heat, radiation, drying and most disinfectants.
Clostridium
I am the leading cause of nosocomial diarrhea, tough to culture, most antibiotics kills the normal flora before me causing pseudomembranous colitis
C. Difficile
I cause cellulitis, gas gangrene, food poisoning. My spore germinate without oxygen, comporomised blood flow, calcium ions and the availability of peptides and amino acids.
C. Perfringens
How do you treat C. Perfringens?
Surgically excise infected muscle, antibiotics, horse antitoxins, high 02 and reestablish blood supply
I have heat resistant spores that can survive food processing, neurotoxins, and I prevent the release of acetylcholine causing flaccid paralysis
C. Botulinum
How do you treat c. Botulinum?
Trivalent antitoxin from horses
What ar the three types of botulism?
Food borne, wound, and infant
I am famous for being found everywhere within your GI tract, but infections follow a traumatic injury - I cause lockjaw and can be treated with DPT vaccine
C. Tetani - tetanus
I am responsible for the symptoms of tetanus by inhibiting GABA release causing reflex spasms and spastic paralysis
Tetanospasmin
What NT is blocked by botulism? What about tetanus?
ACH acetylcholine, GABA (this is the “yoga” NT because it helps muscles relax)
I am a small gram - bacteria with no peptidoglycan (Murien) in my cell wall. I grow intracellularly because I NEED energy (ATP) from my host
Chlamidiae