Gram Postiive Cocci Flashcards
Gram Positive cocci
- S. Aureus
- S. Epididymis
- S. Saprophyticus
- Strep pyrogenes (Group A strep)
- Strep Agalactiae (Group B strep)
- Strep pneumonia
- Strep viridians
- Strep gallalyticus (group D strep)
- Enterococcus Faccium or faecalis
Staph Aureus ID
Gram —-
— shaped
catalase —–
coagulase —–
- Gram positive
- Cocci shaped
- Catalase +
- coagulase +
what test tells staph aureus apart from staph epididymis and staph saprophyticus
- Coagulase +
Staph aureus is —– on blood agar
yellow or golden apperance
Staph aureus is —– hemolytic
beta
Staph aureus causes
- pneumonia with patchy infiltrate
- most common cause of septic arthritis in adults
- most common cause of OM in adults
- causes abscess
what is the main virulence factor of staph aureus
Protein A
What are the toxin mediated diseases caused by staph aureus
- scalded skin syndrome
- Toxic shock syndrome
- Rapid onset food poisoning
Toxic shock syndrome caused by staph aureus
- can be caused by leaving a tampon on for too long
- causes a cytokine storm
Rapid onset food poisoning caused by staph aureus
- Associated with vomiting than diarrhea
Treatment for staph aureus
- vancomycin
- if methicilin sensitive, use Nafcilin
—- resistance can occur with Staph aureus
MRSA
Staph Epididymis and saprophyticus ID
gram ——
—- shaped
catalase —–
coagulase ——
produces ——
- positive
- cocci
- positive
- negative
- urease
How can you tell staph epididymis from saprophyticus?
Staph epi- novobiosin sensitive
staph sapro- novobiocin resistant
Staph Epi is a normal flora of the ——
skin
staph epi produces —–
biofilm
infections caused by staph epi
- Prosthetic joint infection
- cathether associated infection
- most common cause of endocarditis affecting heart valves
Treatment of staph Epi
Vancomycin
infections caused by staph saprophyticus
- honey moon cystitis which is UTI affecting sexually active females
- Acute bacterial endocarditis
Strep pyrogenes (Group A strep) ID
Gram —–
— shaped
—– capsule made out of ——
- positive
- cocci
- encapsulated capsule made out of hyaluronic acid
How can you tell strep pyrogenes (GAS) from strep agalactiae (GBS)
Bacitracin sensitive
Pyrogenic infections caused by GAS
- impetigo
- Phayngitis (strep throat)
- cellulitis and erysipelas
Impetigo
Honey coated skin infection
Erysipelas
superficial infection with demarcated borders
infections caused by strep pyrogenes toxins
- scarlet fever
- toxic shock like syndrome
- necrotizing fascitis
Scarlet fecer
- redening and swelling of the tongue (strawberry tongue)
- widespread rash that spares the face
What GAS toxins cause scarlet fever and Toxic shock likre syndrome
- SpeA and SpeC
what GAS toxin causes necrotizing faascitis
SpeB
—– is the main virulence factor of GAS responsible for rheumatic fever
M protein
M protein
- interferes with opsonization (anti-phagocytic)
- M protein mimics the myosin in our heart and causes our own antibodies to attack out heart
—– valves are normally affected by rheumatic fever
Mitral valve
Symptoms of rheumatic fever
(JONES CRITERIA)
J- joints, polyarthritis
O- heart problems including murmurs, myocarditis, pericarditis
N- subcutaneous nodules
E- Erythema nodusum
S- Syndenham chorea
Post strep Glomerulonephritis (PSGN)
- occurs after a pharyngitis
- type 3 hypersensitivity
Symptoms of PSGN
- dark brown or cola colored urine
- Facial swelling from edema
- occurs 2 weeks after onset of the initial pharyngitis infection
Rheumatic fever occurs after
Pharyngitis
PSGN occurs after
Pharyngitis or a superficial infection like impetigo
Early diagnosis of pharyngitis can prevent —— but cannot precent —–
- Rheumatic fever
- PSGN
virulence factors of GAS
- Streptolysin O
- streptokinase
- DNAse
streptolysin O
- virulence factor that allows GAS to lyse RBC and be beta hemolytic
- can be used to diagnose pharyngitis
what virulence factor can be used to diagnose pharyngitis
Streptolysin O
Streptokinase
converts plasminogen to plasmin
how do you tell if someone has recently had GAS infection
Antistreptolysin O titers
Treatment of GAS
Penicillin
Strep agalactiae ID
Gram ——
—- shaped
—— positive test
—– resistant
—– positive
- gram positive
- cocci shaped
- Hippurate positive
- bacitracin resistant
- CAMP positive
Strep agalactiae capsule is made out of
Polysaccharide
Strep agalactiae mostly affects
New borns
infections caused by strep agalactiae
- Causes meningitis in neonates (#1 cause)
- Causes sepsis in neonates
- causes pneumonia
How do neonates get strep agalactiae
- through the vaginal canal of the mother during delivery
Mothers are swabbed for strep agalactiae when
at 35 weeks
If the mother is colonized with strep agalactiae, the baby is protected from this by giving the mother ——
Intrapartrum penicillin
Strep pneumonia ID
Gram —–
—- hemolytic
—- shaped
encapsulated with —– capsule
—– protease
—— sensitive
—– soluble
- gram positive
- alpha hemolytic
- cocci shaped
- polysaccharide
- IgA protease
- optochin sensitive
- Bile soluble
—— is the #1 cause of community acquired pneumonia
Strep pnuemonia
Strep pneumonia leads to production of —– sputum
Rust colored
Strep Pneumonia is the cause of which of the following diseases
(MOPS)
Meningitis
Otitis media
Pneumonia
Sinusitis
Individuals that had a splenectomy or autosplenectomy like sickle cell diseases have greater risk of being infected by —— organisms
Encapsulated
Patients with sickle cell diseases are susceptible to —— infection
Strep pneumonia
Treatment of strep pneumonia
- macrolides
- 3rd gen cephalosporins like ceftriaxone
How can you prevent strep pneumonia
VACCINES
- 23 valence for adults, IgM response
- 7 valence for children, causes an IgG response
Strep viridians ID
Gram ——
—- shaped
encapsulated???
—– resistant
—– hemolytic
Gram positive
cocci shaped
not encapsulated
bile resistant
alpha hemolytic
Viridans group especially strep mutans causes ——-
dental carries
Viridans adheres to ——
Platelets
Enterococcus faecium or fecalis is bile —–
Resistant
Enterococcus faecium or faecalis are able to grow in medium of —–
6.5% NaCl
infections caused by enterococcus
- UTIs
- Endocarditis
- infection of the biliary tree
Treatment of enterococcus
- it is nosocomial which means it is resistant to almost every antibiotic including vancomycin; it is a VRE (vancomycin resistant enterococcus)
- linezolid is the go to treatment
- Tigecycline
Strep gallolyticus (strep bovis) (GDS) ID
Gram —–
—- hemolytic
Bile ——
Gram positive
gamma
senstive
Strep gallolyticus is encapuslated in —– capsule
polysaccharide
Strep gallolyticus is a normal —– flora
GI tract
infections caused by strep gallolyticus
- Endocarditis
- Collorectal neoplasia
If a patient is diagnosed with a strep gallolyticus, it is important to obtain a colonoscopy as they may have ——
Colon cancer
Treatment of Strep gallolyticus
- vancomycin
- penicillin
- 3rd gen cephalosporin