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60 Cards in this Set
- Front
- Back
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How is Shigella related to E.Coli?
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It was a E.Coli that gained virulence plamid that lost flagella and certain catabolic pathways and toxins.
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What disease dos shigella cause?
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Dysentery, hemolytic uremic syndrome, and reiter’s syndrome.
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What is reiter’s syndrome?
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Antibodies cross react and cause muscles and joints to swell
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How many cases are there per year?
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20k Officially, but thought to be more. Worldwide 164 million cases, and most deaths are under the age of 5.
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Why does it kill more kids?
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The severe dehydration affects them worse.
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How can you treat Shigella?
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Antibiotics, however that is only sometimes, and it’s going down because of resistance. Most people’s healthy immune system will clear it up. Some species of shigella will get worse if you give them an antibiotic. There are no vaccines.
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What is the requirement for a vaccine? And what is the problem with making a vaccine?
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Long lasting, cheap to make, minimal side effects. There are 4 species and multiple serotypes within those species.
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Mechanism of infection
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Acid resistance genes, get into intestines, produce M cells and infect macrophages. Induce apoptosis and enter epithelial cell of intestines and spread from cell to cell.
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How do they infect the cell?
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Type 3 secretion system
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How does the type 3 secretion system work?
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It is a needle complex that is used to push proteins into a cell. It turns off the cellular alarms, causes actin to engulf the bacteria
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Can shigella move on their own?
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No.
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How can shigella move?
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They recruit actin to propel it.
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What contains the genes that shigella needs to inject proteins?
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Large virulence plasmid.
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Entry region
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the part of the virulence plasmid that contains all of the genes that a shigella needs to inject the proteins |
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How did epidemiologists find the source of the outbreak of shigella in the us?
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Yelp reviews
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How is shigella transferred?
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Fecal oral route.
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Why is shigella more dangerous than E.Coli?
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It only takes 10-100 cells to contract dysentery. It takes 1 million cells to get an E.coli infection.
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What are the symptoms of dysentery?
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8-48 hours no symptoms, then cramps, watery diarrhea, bloody diarrhea, stomach ache, dehydration, nausea.
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What is the leading cause of bacterial meningitis and septic shock
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Neisseria meningitides
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What is the 2nd most prevalent STD in the US?
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Gonorrhea
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Although it doesn’t always have symptoms, what can it do?
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Cause 60% of cervical infections, cause PID, and fecillitate HIV transmission
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Treatment for Neisseria gonorrhoeae?
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No vaccine. And it’s super anti-biotic resistant.
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What is a superbug
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A disease where there is a risk of it becoming untreatable
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What is competence and how is it a problem in gonorrhea?
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It is the ability to take up DNA around it, and gonorrhea is covered in pili and is super duper competent.
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If you get symptoms of gonorrhea, what are they?
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Cervitis and ectopic pregnancies in females, and the swelling of the prostate and testes in males. Disseminated conococcal infection, tenosyvnovitis, arthritis, septicemia in any sex. And it can get IN THE EYES. NOOOOOO.
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How do type 4 pili work?
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Recruit of proteins to the site of adhesion, they mediate attachment to host cells, they can interact with other pili and form aggragates called a microcolony. They can be used to move (twitching) and can take up DNA.
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What are the stages of infection?
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Loose adherence, microcolony formation, tight adherence, invasion, intracellular replication, and trascytosis
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What is transcytosis
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When the disease can migrate out of the cell and get into deeper tissue
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What are opa proteins?
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Beta barrel proteins which appear opaque. There can be up to 12 per gonococci
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How are Opa proteins interesting on gel electrophoresis.
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They are heat modifiable. It will run at a different length.
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How many surface exposed loops are OPA’s predicted to have?
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Four.
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What are The presence of antibodies to multiple proteins is associated with what?
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A reduced risk of PID
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Define exfoliation
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innate defense mechanism where epithelial cells slough off
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What is one way people are thinking to make new treatments
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Block interaction of OPA and CEACANS. Antibodies to surface components It will lock the ability to bind to the cell it wants to infect.
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What is the problem with the meningitis vaccine?
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IT doesn’t protect against all serogropus
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How many serogroups is in N meningitides?
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12
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How many serogroups are associated in human diseases?
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5
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What is important with serogroup B?
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It causes 50% of all cases worldwide |
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What serogroup predominates in Africa?
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A
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What are the symptoms of meningitis?
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Basically a hangover, otherwise shivering, rash, vacant, seizures, and delirious.
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Why is serogroup B a problem for making vaccines?
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It is non immunogenic and resembles a self antigen.
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What is Staphylococcus aureus?
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G+ commensal/opportunistic bacteria which can cause a broad range of diseases. It resides in about 30% of the human population
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Diseases caused by staph?
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Meningitis/brain abscesses, pneumonia, endocarditis, food poisoning, toxic shock syndrome, septic arthritis, and osteomyelitis.
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What are the mild affects of staph?
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Soft tissue infections, boils, skin abscesses, food poisoning
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What should you know about food poisoning by staph?
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It isn’t fatal, it stimulates the vagus nerve and causes projectile vomiting.
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What are the moderate affects of staph?
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Impetigo and cellulitis, scalded skin syndrome
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What causes SSSS? How?
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Exfoliative toxin. It separates the epidermis from the dermis. It’s painful. It contributes to the spread of the staph
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What are the severe affects of staph?
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Toxic shock, septicemia, and necrotizing fasciitis.
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What is toxic shock syndrome and how does it occur?
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It is the result of the body’s response to TSST-1 which is a superantigen. It causes a massive activation of TCells in the bodyand a massive cytokine release. Symptoms include: high fever, rash, desquamation, hypotension, multiorgan failure, and death.
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Is MRSA the same thing as Staph?
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No! MRSA is only a percentage of staph infections (thank god)!
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What makes MRSA, MRSA?
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SCCmec is acquired in the genome.
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What are the two types of MRSA?
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Hospital associated and community associated
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Which version of MRSA is more antibiotic resistant?
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Hospital acquired
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Which version of MRSA produces higher levels of toxins?
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Community associated
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What is an important drug that took the longest time to report any resistance to?
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Vancomycin
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Why isn’t there a vaccine for staph?
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We’re trying but nothing passed phase 2/3!!!
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What is pathenogenic about staph?
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There are pore forming toxins (they’ll punch holes in your cells), there are exoenzymes, there are virulence factors, it’s a mess!
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What are pore forming toxins?
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Cytotoxins that will do receptor based cell type specificity and punch holes in only VERY SPECIFIC cells
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What exoenzymes are good for you to know and what do they do?
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Proteases, nucleases. Proteases degrade the bacterial cell surface, cleave human plase proteinase inhibitors. Nuclease degrades neutrophil extracellular traps.
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How does staph hide from the immune system?
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It binds with the complement binding site and the antibodies are bound the wrong way. It makes opsonization impossible and ends up hiding from phagocytic cells.
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