Micro- Diebel Flashcards
Describe the difference between alpha, beta, and gamma hemolysis
gamma= no hemolysis Beta = will completely destroy RBCs alpha = partial damages them
What organisms have B-hemolysis?
Staph
Strep pyogenes
What organism has alpha hemolysis?
Step viridans
How would you distinguish between the different kinds of strep?
ALL: Gram +, cooci, catalse -
S.mutans= alpha hemolytic, bacitracin resistant
S. pyogenes = B-hemolytic, bacitracin sensitive
Which of the strep species is bacitracin sensitive?
S. pyogenes
What virulence factor is CAR proteins associated with? what do they do?
Pericarditis
Myocarditis
Binding proteins (attachment)
What is the triad for RMSF?
Fever
Rash (hands and soles)
Headache
Will also see muscles aches, malasie
What organism causes RMSF?
Rickettsia Rickettsia
What is unique about rickettsia rickettsia?
Obligate intracellular parasite.
Needs to use host ATP
(Only other organism like this is clamydia)
What organism produces dextran inorder to make a glycocalyx?
Strep viridans
FimA
Gsp B
Strep vidirdans
FnbpA
Staph
M proteins
Found in strep pyogenes
Used to resist phagocytosis
Abs cross react w/meromyosin on heart and cause rheumatic heart disease
What kind of hypersensitivity is Abs cross reacting with M protein and meromyosin?
TYPE II HYPERSENSITIVITY
What does streptolysin O do?
Destroys RBCs
What does streptolysin S do?
Destroys WBCs
What does streptokinase do?
Converts plasminogen to plasmin
What does hyalouronidase do?
Breaks down connective tissue
What are the virulence factors for rickettsia rickettsia?
OmpA & OmpB - attachment
T4SS - host cell entry
What is the age range for acute rheumatic fever?
5-14 years old
What type of hypersensitivity is osler’s nodes and roth spots?
Type III hypersensitivity
What is the most common cause of Community-Acquired Native Valve Endocarditis?
Streptococci
Most common cause of nosocomial native valve endocarditis?
Staph aureus
Which staph species is coagulase negative?
Staph Epidermidis
What disease is this? “chest pain which becomes worse when patient is swallowing or supine is the most common symptom.”
Pericarditis
How does bacterial pericarditis differ from viral pericarditis?
more acute, severe and has fever and tachypnea
Besides Coxsackie A, B, and echoviruses, what other organisms can cause Pericarditis? (5 more)
Staph aureus strep pneumo Haemophilus influenzae Neisseria meningitidis Influenza virus
Most likely causative agent of IV catheter-related infections?
staph aureus
What is the predominant infectious agent during the initial year following prosthetic valve surgery?
Staph epidermidis
What is the most likely organism to infect a prosthetic valve more than 1 year after the surgery?
Strep viridans
What do you see clinically in a patient with valvular infection?
Fever as part of an associated endocarditis
Heart murmur
After implantation of a pacemaker of defibrillator, what is the most common infection within 2 weeks of the implantation?
Staph aureus
After pacemaker/defibrillator implantation, what is the most common infection 2 weeks-1 year after implantation?
Staph epidermidis
One year after pacemaker/defibrillator implantation-what bug predominates infection?
Strep Viridans
Besides staph aureus, staph epidermidis, and strep viridans, what other bug can cause infection after defibrillator or pacemaker implantation?
Enterococci species
How long does it take the clinical signs of RMSF to appear after infection?
1-2 weeks
In RMSF, what causes the petechial rash?
Rickettsia attach and are engulfed into epithelial cells–>multiply and spread to nearby cells–>replication casues RBC leakage
