MICRO - Bacteria Associated with CVS and Lymphatic Infections 1 (Staphylococcus, Streptococcus, Enterococcus)

Gram-positive

What is the Gram reaction of Staphylococcus species?

Cocci in clusters

What is the microscopic arrangement of Staphylococcus?

Facultative anaerobe

What oxygen requirement do Staphylococci have?

Catalase test

What test distinguishes Staphylococci from Streptococci?

Catalase positive

What is the catalase result of Staphylococcus aureus?

Coagulase positive

What is the coagulase result of Staphylococcus aureus?

Beta-hemolysis

What hemolysis pattern does Staphylococcus aureus show?

MSA

What medium turns yellow due to mannitol fermentation by Staphylococcus aureus?

Anterior nares

Where is Staphylococcus aureus commonly carried in humans?

Person to person

What type of transmission commonly spreads Staphylococcus aureus?

Polysaccharide capsule

What structure of S. aureus inhibits phagocytosis?

Slime layer

What layer promotes biofilm formation in S. aureus?

Coagulase

What enzyme of S. aureus clots plasma?

Catalase

What enzyme of S. aureus breaks down hydrogen peroxide?

Clumping factor

What protein helps S. aureus adhere to fibrinogen and cause clumping?

Staphylokinase

What S. aureus enzyme digests fibrin clots?

Nasal carriage

What common colonization site increases risk for S. aureus infection?

Prosthetic devices

What type of prosthesis increases the risk for S. aureus infection?

IV drug use

Which patient practice increases risk of acute right-sided endocarditis?

Pacemaker

What implanted cardiac device increases risk of S. aureus endocarditis?

Diabetes mellitus

What metabolic disease is a risk factor for S. aureus infection?

Hemodialysis

What medical therapy increases risk for S. aureus bacteremia?

Acute endocarditis

What type of endocarditis does S. aureus commonly cause?

Less than 2 weeks

How fast does S. aureus endocarditis develop?

Tricuspid valve

What heart valve is most affected in IV drug users with S. aureus endocarditis?

Vegetations

What structure forms on valves in S. aureus endocarditis?

Platelets and fibrin

What microscopic mixture composes vegetations?

Friable

What feature makes vegetations dangerous due to embolization?

Coagulase-negative

What is the coagulase result of Staphylococcus epidermidis?

Non-hemolytic

What is the hemolysis pattern of Staphylococcus epidermidis?

MSA negative

What is the mannitol fermentation result of Staphylococcus epidermidis?

Skin flora

Where is Staphylococcus epidermidis normally found?

Nosocomial infections

What type of infection is Staphylococcus epidermidis strongly associated with?

IV catheters

What type of medical device is frequently infected by Staphylococcus epidermidis?

Early prosthetic valve endocarditis

What type of prosthetic infection is Staphylococcus epidermidis the most common cause of?

Biofilm

What major virulence factor allows S. epidermidis adherence to plastics?

PIA

What polysaccharide in S. epidermidis forms the biofilm matrix?

Delta toxin

What exotoxin is produced by Staphylococcus epidermidis?

Bacteremia

What bloodstream infection is commonly caused by S. epidermidis in hospitalized patients?

Prosthetic valve endocarditis

What endocarditis is commonly due to S. epidermidis?

Catheter infection

What device-associated infection is typical of S. epidermidis?

Ventricular shunt

What CNS device is often infected by S. epidermidis?

Gram positive cocci

What Gram stain result identifies Staphylococcus?

Catalase test

What test produces bubbles for Staphylococci?

Coagulase test

What test differentiates S. aureus from other staphylococci?

Novobiocin

What antibiotic distinguishes Staphylococcus saprophyticus from S. epidermidis?

Susceptible

What is the novobiocin result for S. epidermidis?

Resistant

What is the novobiocin result for Staphylococcus saprophyticus?

Yellow

What color do S. aureus colonies turn on MSA?

Pink

What color do S. epidermidis colonies remain on MSA?

Beta-hemolysis

What hemolysis is shown by S. aureus?

None

What hemolysis is shown by S. epidermidis?

Nafcillin

What drug treats methicillin-sensitive Staphylococcus aureus?

Cefazolin

What first-generation cephalosporin treats MSSA?

Vancomycin

What drug is preferred for methicillin-resistant S. aureus?

Daptomycin

What lipopeptide drug is an alternative for MRSA?

Linezolid

What oxazolidinone drug is used for MRSA infection?

Quinupristin-dalfopristin

What drug combination is an alternative MRSA treatment?

Handwashing

What basic hygiene practice prevents Staphylococcus transmission?

Mupirocin

What topical agent eradicates S. aureus nasal carriage?

Nasal surveillance

What facility practice screens high-risk patients for S. aureus?

Aseptic technique

What practice is essential during wound care to prevent infection?

MSA

What medium is used to grow Staphylococcus with high salt concentration?

Catalse

What enzyme distinguishes Staphylococcus from Streptococcus?

Coagulase

What enzyme distinguishes S. aureus from S. epidermidis?

Staphylococcus epidermidis

What staphylococcal species is the most common cause of nosocomial bacteremia?

Staphylococcus aureus

What species is the most common cause of acute endocarditis?

Staphylococcus epidermidis

What species is associated with early prosthetic valve infection?

Endocarditis

What infection is commonly caused by S. aureus spread via lymphatics?

Salt tolerance

What feature of staphylococci allows survival on dry skin?

Gram stain

What stain demonstrates grape-like clusters?

Fibrin coating

What structure forms protective layers over S. aureus colonies in endocarditis?

Bacteremia

What bacterial process seeds S. aureus into blood continuously?

Capsule

What S. aureus virulence structure is responsible for antiphagocytosis?

Gram positive

What is the Gram reaction of Streptococcus species?

Cocci in chains

What is the microscopic arrangement of Streptococcus species?

Catalase negative

What is the catalase result of Streptococcus species?

Facultative anaerobe

What oxygen requirement do Streptococci have?

Group A

What Lancefield group corresponds to Streptococcus pyogenes?

Catalase test

What Barton test differentiates Staphylococcus and Streptococcus

Beta-hemolysis

What hemolysis pattern does Streptococcus pyogenes exhibit?

Pharynx

What mucosal region commonly harbors S. pyogenes?

M protein

What protein of S. pyogenes causes immune cross-reactivity with the heart?

Rheumatic fever

What condition arises from M protein cross-reactivity with heart tissues?

Acute glomerulonephritis

What immune complex disease follows skin infection by S. pyogenes?

Pharyngitis

What infection precedes rheumatic fever?

Bacitracin test

What test identifies S. pyogenes sensitivity to bacitracin?

Sensitive

What is the bacitracin result for S. pyogenes?

M protein

What factor allows S. pyogenes to resist phagocytosis?

Streptolysin O

What toxin of S. pyogenes causes hemolysis?

Streptokinase

What enzyme allows S. pyogenes to dissolve clots?

DNase

What enzyme hydrolyzes DNA in pus?

Erythrogenic toxin

What exotoxin causes scarlet fever?

Hyaluronidase

What enzyme of S. pyogenes breaks down hyaluronic acid?

Pyrogenic exotoxin

What toxin allows S. pyogenes to cause toxic shock?

Strep pharyngitis

What throat infection is most commonly caused by S. pyogenes?

Impetigo

What skin infection presents as honey-crusted lesions?

Necrotizing fasciitis

What necrotic infection is caused by S. pyogenes?

Rheumatic fever

What post-infectious disease presents with carditis and arthritis?

Post-streptococcal glomerulonephritis

What kidney condition presents with hematuria and proteinuria?