Micro 19 Flashcards

A patient develops subacute endocarditis after a genitourinary procedure. Which organism group is classically associated?

A. Group A Streptococci

B. Group D Streptococci

C. Viridans streptococci

D. Staphylococcus aureus

Which organisms are Group D Streptococci associated with subacute endocarditis after GI/GU procedures?

A. E. faecalis and E. faecium

B. S. pyogenes and S. agalactiae

C. S. pneumoniae and S. bovis

D. S. aureus and S. epidermidis

Viridans streptococci most commonly cause endocarditis involving which valves?

A. Previously normal valves

B. Prosthetic valves

C. Previously damaged valves

D. Right-sided valves only

A patient develops slowly progressive endocarditis several weeks after a dental procedure. Which organism is most likely?

A. Enterococcus faecalis

B. Streptococcus pneumoniae

C. Staphylococcus aureus

D. Viridans streptococci

Which description best characterizes viridans streptococcal endocarditis?

A. Low virulence, gradual onset

B. High virulence, rapid destruction

C. Acute onset, large abscesses

D. Normal valves, rapid progression

Viridans streptococcal subacute endocarditis typically produces which valvular finding?

A. Valve perforation

B. Small nondestructive vegetations

C. Massive valve necrosis

D. Large destructive vegetations

A patient with subacute endocarditis is found to have Streptococcus gallolyticus bacteremia. Which underlying disease should be suspected?

A. Gastric carcinoma

B. Renal cell carcinoma

C. Colorectal carcinoma

D. Pancreatic carcinoma

Streptococcus bovis is another name associated with which organism?

A. S. pyogenes

B. S. pneumoniae

C. S. agalactiae

D. S. gallolyticus

A patient with functional asplenia from sickle cell disease is especially susceptible to which organism?

A. Enterococcus faecalis

B. Streptococcus pneumoniae

C. Streptococcus pyogenes

D. Viridans streptococci

Which group contains only organisms commonly infecting asplenic sickle cell patients?

A. GAS, enterococci, viridans

B. GAS, pneumococcus, enterococci

C. Pneumococcus, meningococcus, H. influenzae

D. Viridans, meningococcus, enterococci

What is the major function of the GAS M protein?

A. Activates plasminogen

B. Produces erythrogenic toxin

C. Promotes bacterial motility

D. Inhibits phagocytosis and complement

Which GAS virulence factor is antiphagocytic and inhibits complement activation?

A. M protein

B. Streptokinase

C. SpeB

D. Erythrogenic exotoxin

Which GAS virulence factor converts plasminogen into plasmin?

A. M protein

B. Streptokinase

C. SpeB

D. Hyaluronidase

Why can streptokinase be therapeutically useful in patients with clots?

A. Activates complement

B. Inhibits platelet aggregation

C. Promotes fibrinolysis

D. Blocks thrombin formation

Streptokinase is a virulence factor of which gram-positive organism?

A. Enterococcus faecalis

B. Streptococcus pneumoniae

C. Viridans streptococci

D. Streptococcus pyogenes

Scarlet fever is mediated by which GAS virulence factor?

A. Erythrogenic exotoxin

B. M protein

C. Streptokinase

D. SpeB

A child with streptococcal pharyngitis develops a “beefy-red” tongue. Which syndrome is most likely?

A. Rheumatic fever

B. Scarlet fever

C. Necrotizing fasciitis

D. Toxic shock syndrome

A patient develops a toxic shock-like syndrome caused by a gram-positive coccus. Which organism is responsible according to these notes?

A. Streptococcus pneumoniae

B. Enterococcus faecium

C. Streptococcus pyogenes

D. Viridans streptococci

A patient develops a sharply demarcated erythematous skin infection involving the upper dermis and superficial lymphatics. Which diagnosis is most likely?

A. Cellulitis

B. Impetigo

C. Necrotizing fasciitis

D. Erysipelas

Which organism is the classic cause of erysipelas in these notes?

A. Group A Streptococcus

B. Enterococcus faecalis

C. Streptococcus pneumoniae

D. Viridans streptococci

Following minor trauma, a patient rapidly develops severe soft-tissue infection with necrotic skin and large bullae. Which diagnosis is most likely?

A. Erysipelas

B. Necrotizing fasciitis

C. Scarlet fever

D. Cellulitis

Which organism is associated with necrotizing fasciitis entering through traumatic skin openings?

A. Streptococcus pneumoniae

B. Enterococcus faecium

C. Group A Streptococcus

D. Viridans streptococci

A patient develops rheumatic fever after GAS pharyngitis. Antibodies against which bacterial factor cross-react with cardiac myosin?

A. Streptokinase

B. SpeB

C. Erythrogenic toxin

D. M protein

Poststreptococcal glomerulonephritis occurs after infection with nephritogenic strains of which organism?

A. Group A β-hemolytic Streptococcus

B. Viridans streptococci

C. Enterococcus faecalis

D. Streptococcus pneumoniae

Which virulence factor is carried by nephritogenic GAS strains associated with PSGN?

A. Streptokinase

B. M protein

C. Capsule

D. Pneumolysin

PSGN results from glomerular deposition of nephritogenic antigens such as which GAS product?

A. Streptolysin O

B. M protein

C. SpeB

D. Streptokinase

A child develops cola-colored urine and facial swelling several weeks after streptococcal pharyngitis. Which complication is most likely?

A. Rheumatic fever

B. Poststreptococcal glomerulonephritis

C. Scarlet fever

D. Toxic shock syndrome

Which infections can precede poststreptococcal glomerulonephritis?

A. Pharyngitis or skin infection

B. Pneumonia or meningitis

C. UTI or endocarditis

D. Otitis or sinusitis

Which urinary finding is characteristic of PSGN?

A. Glycosuria

B. Pyuria

C. Cola-colored hematuria

D. Nephrotic proteinuria

Which additional finding commonly accompanies PSGN?

A. Leg paralysis

B. Diarrhea

C. Jaundice

D. Facial swelling

GAS erythrogenic exotoxin genes are carried by which genetic element?

A. Lysogenic phage

B. Plasmid

C. Transposon

D. Bacterial chromosome

Transfer of GAS erythrogenic toxin genes occurs through which mechanism?

A. Transformation

B. Conjugation

C. Specialized transduction

D. Generalized transduction

Which test is characteristically positive for Streptococcus agalactiae?

A. Optochin test

B. CAMP test

C. Coagulase test

D. Catalase test

A positive CAMP test demonstrates enhanced hemolysis when GBS is plated beside which organism?

A. Streptococcus pneumoniae

B. Enterococcus faecalis

C. Streptococcus pyogenes

D. Staphylococcus aureus

Streptococcus agalactiae most commonly causes disease in which population?

A. Neonates

B. Adolescents

C. Young adults

D. Elderly adults

Which respiratory complication is associated with neonatal GBS infection?

A. Bronchiolitis

B. Pulmonary fibrosis

C. Neonatal pneumonia

D. Croup

The pneumococcal polysaccharide vaccine given to adults primarily induces which antibody response?

A. IgA

B. IgM

C. IgE

D. IgG

The pneumococcal conjugate vaccine used in children primarily induces which antibody response?

A. IgM

B. IgA

C. IgE

D. IgG

Which Streptococcus pneumoniae virulence factor promotes mucosal colonization?

A. IgA protease

B. Streptokinase

C. Hyaluronidase

D. M protein

Streptococcus pneumoniae IgA protease facilitates adherence to which site?

A. Cardiac valves

B. Renal glomeruli

C. Mucous membranes

D. Subcutaneous tissue

Streptococcus pneumoniae shares important virulence factors with which organisms?

A. GAS and enterococci

B. Hib and Neisseria

C. Staphylococci and Klebsiella

D. Mycoplasma and Legionella

Which organism commonly contributes to dental plaque formation?

A. Streptococcus pneumoniae

B. Streptococcus agalactiae

C. Streptococcus pyogenes

D. Viridans streptococci

Which viridans species are specifically associated with dental plaque?

A. Mutans and sanguinis

B. Faecalis and faecium

C. Pyogenes and agalactiae

D. Pneumoniae and bovis

Which organism most commonly causes erysipelas?

A. Staphylococcus aureus

B. Enterococcus faecalis

C. Streptococcus pneumoniae

D. Streptococcus pyogenes

Which organisms most commonly cause cellulitis?

A. S. aureus and S. pyogenes

B. GBS and viridans

C. Pneumococcus and enterococci

D. HACEK and S. bovis

Streptokinase belongs to which drug class when used therapeutically?

A. Anticoagulants

B. Antiplatelets

C. Thrombolytics

D. Vasodilators

Which cephalosporin can treat viridans streptococcal and HACEK endocarditis?

A. Cefazolin

B. Ceftriaxone

C. Cephalexin

D. Cefuroxime

Streptococcus bovis bacteremia with subacute endocarditis should prompt which procedure?

A. Bronchoscopy

B. Cystoscopy

C. Endoscopy

D. Colonoscopy

Why is colonoscopy indicated with Streptococcus bovis infection?

A. Suspect colorectal carcinoma

B. Suspect gastric carcinoma

C. Suspect renal carcinoma

D. Suspect pancreatic carcinoma

Which host protein is bound by GAS M protein?

A. Factor VIII

B. Factor V

C. Factor H

D. Factor X

Binding of factor H by GAS M protein ultimately promotes breakdown of which complex?

A. Membrane attack complex

B. C3 convertase

C. Prothrombin complex

D. Factor Xa complex

Streptococcus pyogenes is also known by which designation?

A. Group B Streptococcus

B. Viridans streptococcus

C. Group D Streptococcus

D. Group A Streptococcus

The capsule of Streptococcus pyogenes is composed of what substance?

A. Hyaluronic acid

B. Polysialic acid

C. Dextran

D. Peptidoglycan

What hemolysis pattern characterizes Streptococcus pyogenes?

A. Alpha hemolysis

B. Gamma hemolysis

C. Beta hemolysis

D. No hemolysis

A child develops honeycomb-like crusted skin lesions without bullae. Which diagnosis is most likely?

A. Erysipelas

B. Nonbullous impetigo

C. Cellulitis

D. Scarlet fever

Which organism commonly causes nonbullous impetigo with honeycomb-like crusts?

A. Streptococcus pneumoniae

B. Streptococcus agalactiae

C. Enterococcus faecalis

D. Streptococcus pyogenes

A child presents with sore throat and cervical lymphadenopathy. Which GAS-associated disease is most likely?

A. Pharyngitis

B. Erysipelas

C. Endocarditis

D. Pneumonia

Which GAS enzyme breaks down connective tissue and facilitates cellulitis spread?

A. Streptokinase

B. IgA protease

C. Hyaluronidase

D. Coagulase

Systemic release of GAS exotoxins A, B, and C produces which syndrome?

A. Rheumatic fever

B. Scarlet fever

C. PSGN

D. Erysipelas

A child has streptococcal pharyngitis, strawberry tongue, and a diffuse sandpaper-like rash. Which diagnosis is most likely?

A. Erysipelas

B. Impetigo

C. PSGN

D. Scarlet fever

Which feature characteristically describes the rash of scarlet fever?

A. Spares the face

B. Confined to face

C. Produces large bullae

D. Causes dermal necrosis

Which Streptococcus pyogenes exotoxins are associated with toxic shock-like syndrome?

A. SpeA and SpeC

B. SpeB and SpeC

C. Streptolysin O and S

D. DNase-B and SpeB

Which Streptococcus pyogenes virulence factor is associated with necrotizing fasciitis?

A. Streptokinase

B. SpeB

C. M protein

D. DNase-B

Which GAS cell-wall virulence factor primarily inhibits phagocytosis?

A. Streptolysin O

B. Hyaluronidase

C. M protein

D. Streptokinase

The molecular structure of GAS M protein resembles which human protein?

A. Collagen

B. Actin

C. Troponin

D. Myosin

Antibodies generated against GAS M protein may cross-react with myosin in which tissue?

A. Cardiac muscle

B. Skeletal muscle

C. Smooth muscle

D. Vascular endothelium

Rheumatic fever develops through cross-reactivity between GAS M protein and what?

A. Bacterial exotoxins

B. Self-antigens

C. Complement proteins

D. Immunoglobulin molecules

Which GAS infection classically precedes rheumatic fever?

A. Cellulitis

B. Impetigo

C. Pharyngitis

D. Erysipelas

Which GAS infection does NOT typically precede rheumatic fever?

A. Tonsillitis

B. Pharyngitis

C. Streptococcal sore throat

D. Impetigo

Rheumatic fever represents which hypersensitivity reaction?

A. Type II

B. Type I

C. Type III

D. Type IV

A child recently infected with Streptococcus pyogenes is at risk for which two immune-mediated complications?

A. Scarlet fever and cellulitis

B. Rheumatic fever and PSGN

C. Erysipelas and impetigo

D. Sepsis and pneumonia

Approximately how long after GAS infection does PSGN typically develop?

A. Two hours

B. Two weeks

C. Two months

D. Two years

A child receives prompt treatment for GAS pharyngitis. Which complication can still occur despite early treatment?

A. Rheumatic fever

B. Scarlet fever

C. PSGN

D. Erysipelas

Early diagnosis and treatment of streptococcal pharyngitis can prevent which complication?

A. PSGN

B. Necrotizing fasciitis

C. Impetigo

D. Rheumatic fever

Which GAS virulence factors can lyse both erythrocytes and leukocytes?

A. Streptolysin O and S

B. SpeA and SpeC

C. M protein and SpeB

D. DNase-B and streptokinase

Which GAS virulence factor converts plasminogen into plasmin?

A. DNase-B

B. Streptokinase

C. M protein

D. Streptolysin S

Which GAS virulence factor depolymerizes extracellular DNA?

A. SpeA

B. M protein

C. Streptolysin O

D. DNase-B

Elevated ASO or anti-DNase B antibody titers provide evidence of what?

A. Recent GBS infection

B. Recent GAS infection

C. Prior pneumococcal infection

D. Current staphylococcal infection

Which antibody titer can support recent Streptococcus pyogenes infection?

A. Anti-CAMP

B. Anti-capsular IgM

C. Anti-streptolysin O

D. Anti-hyaluronidase IgE

Group B Streptococcus is another name for which organism?

A. Streptococcus pyogenes

B. Streptococcus pneumoniae

C. Streptococcus mutans

D. Streptococcus agalactiae

Which biochemical characteristic is associated with Streptococcus agalactiae?

A. Hippurate positive

B. Bacitracin sensitive

C. Optochin sensitive

D. Coagulase positive

Does Streptococcus agalactiae possess a capsule, and if so, what type?

A. No capsule

B. Polysaccharide capsule

C. Hyaluronic acid capsule

D. Protein capsule

Which pair of organisms is CAMP-test positive?

A. GAS and GBS

B. GBS and pneumococcus

C. GBS and Listeria

D. Listeria and GAS

What does a positive CAMP test demonstrate when GBS is cultured with Staphylococcus aureus?

A. Increased hemolysis zone

B. Decreased hemolysis zone

C. Loss of capsule

D. Bacitracin sensitivity

Which group contains the major neonatal diseases caused by Streptococcus agalactiae?

A. Pharyngitis, cellulitis, impetigo

B. Meningitis, sepsis, pneumonia

C. Endocarditis, UTI, cholangitis

D. Arthritis, otitis, sinusitis

Streptococcus agalactiae normally colonizes which maternal sites?

A. Skin and nasopharynx

B. Oral cavity and lungs

C. GI tract and vagina

D. Bladder and kidneys

A mother colonized with Streptococcus delivers vaginally. What organism can be transmitted to the neonate?

A. Streptococcus pyogenes

B. Streptococcus pneumoniae

C. Streptococcus viridans

D. Streptococcus agalactiae

What is the treatment of choice for Streptococcus agalactiae infection?

Which Gram-stain characteristic describes Streptococcus agalactiae?

A. Gram-negative

B. Acid-fast

C. Gram-positive

D. Gram-variable

Which catalase result is expected for Streptococcus agalactiae?

A. Catalase negative

B. Catalase positive

C. Oxidase positive

D. Coagulase positive

Which hemolysis pattern is produced by Streptococcus pneumoniae?

A. Beta hemolysis

B. Gamma hemolysis

C. Complete hemolysis

D. Alpha hemolysis

Which hemolysis pattern characterizes viridans streptococci?

A. Beta hemolysis

B. Alpha hemolysis

C. Gamma hemolysis

D. No hemolysis

Why does alpha-hemolysis produce a green hue around bacterial colonies?

A. Hemoglobin oxidation

B. RBC agglutination

C. Bilirubin production

D. Capsule pigmentation

Which two virulence factors are characteristic of Streptococcus pneumoniae?

A. M protein and streptokinase

B. Protein A and coagulase

C. Polysaccharide capsule and IgA protease

D. Hyaluronidase and streptolysin O

What is the major function of the pneumococcal polysaccharide capsule?

A. Promotes DNA degradation

B. Inhibits phagocytosis

C. Enhances fibrinolysis

D. Oxidizes hemoglobin

Which Streptococcus pneumoniae virulence factor promotes mucosal colonization?

A. Streptolysin S

B. M protein

C. Coagulase

D. IgA protease

What is the characteristic morphology of Streptococcus pneumoniae?

A. Lancet-shaped diplococci

B. Grape-like cocci

C. Boxcar-shaped bacilli

D. Curved gram-negative rods

Which laboratory property is characteristic of Streptococcus pneumoniae?

A. Bile insoluble

B. Bile soluble

C. Catalase positive

D. Coagulase positive

An adult presents with community-acquired bacterial pneumonia. Which organism is the most common cause?

A. Streptococcus agalactiae

B. Streptococcus viridans

C. Streptococcus pneumoniae

D. Streptococcus pyogenes

A patient presents with lobar pneumonia and rust-colored sputum. Which organism is most likely?

A. Streptococcus pneumoniae

B. Streptococcus agalactiae

C. Streptococcus viridans

D. Enterococcus faecalis

Which pulmonary presentation is classically associated with Streptococcus pneumoniae?

A. Interstitial pneumonia

B. Lung abscess

C. Bronchiolitis

D. Lobar pneumonia

Which sputum description classically suggests pneumococcal pneumonia?

A. Currant-jelly

B. Rust-colored

C. Frothy pink

D. Clear mucoid

The mnemonic C-MOPS describes common diseases caused by which organism?

A. Streptococcus pyogenes

B. Streptococcus agalactiae

C. Streptococcus pneumoniae

D. Streptococcus viridans

Which group contains only diseases included in pneumococcal C-MOPS?

A. Conjunctivitis, meningitis, otitis, pneumonia, sinusitis

B. Cellulitis, meningitis, otitis, pneumonia, sepsis

C. Conjunctivitis, myocarditis, osteomyelitis, pneumonia, sepsis

D. Cholangitis, meningitis, otitis, pharyngitis, sinusitis

Which CNS infection is commonly caused by Streptococcus pneumoniae?

A. Encephalitis

B. Brain abscess

C. Myelitis

D. Meningitis

Which ear infection is commonly caused by Streptococcus pneumoniae?

A. Otitis externa

B. Otitis media

C. Mastoiditis

D. Labyrinthitis

Which upper respiratory infection is commonly caused by Streptococcus pneumoniae?

A. Epiglottitis

B. Pharyngitis

C. Sinusitis

D. Laryngitis

Which ocular infection is included in the pneumococcal C-MOPS mnemonic?

A. Conjunctivitis

B. Keratitis

C. Uveitis

D. Retinitis

Why are asplenic patients particularly susceptible to Streptococcus pneumoniae?

A. It produces M protein

B. It survives in macrophages

C. It forms intracellular spores

D. It has a polysaccharide capsule

A patient with sickle cell disease is particularly susceptible to Streptococcus pneumoniae because of what associated problem?

A. Excess complement activation

B. Functional asplenia

C. Excess neutrophil activity

D. Increased IgA production

Which antibiotic can be used to treat Streptococcus pneumoniae infection?

A. Metronidazole

B. Acyclovir

C. Ceftriaxone

D. Amphotericin B

Which macrolide may be used to treat Streptococcus pneumoniae?

A. Ceftriaxone

B. Penicillin G

C. Vancomycin

D. Azithromycin

Is Streptococcus viridans encapsulated?

A. Yes, hyaluronic acid capsule

B. No capsule

C. Yes, polysaccharide capsule

D. Yes, protein capsule

Group A Streptococcus may cause pharyngitis with which associated finding?

A. Cervical lymphadenopathy

B. Facial edema

C. Hematuria

D. Diarrhea

Streptococcus viridans demonstrates which response to bile?

A. Bile soluble

B. Bile variable

C. Bile insoluble

D. Bile dependent

A patient has multiple dental caries caused by a viridans streptococcus. Which organism is most likely?

A. Streptococcus mutans

B. Streptococcus sanguinis

C. Streptococcus mitis

D. Streptococcus bovis

Which viridans Streptococcus species is associated with subacute endocarditis?

A. Streptococcus mitis

B. Streptococcus sanguinis

C. Streptococcus mutans

D. Streptococcus gallolyticus

Which viridans Streptococcus species is associated with endocarditis described as non-subacute in these notes?

A. Streptococcus mutans

B. Streptococcus sanguinis

C. Streptococcus mitis

D. Streptococcus pyogenes

Which valve is most commonly affected by endocarditis caused by Streptococcus sanguinis or Streptococcus mitis?

A. Aortic valve

B. Pulmonic valve

C. Tricuspid valve

D. Mitral valve

Which Enterococcus species is more common?

A. Enterococcus faecium

B. Enterococcus faecalis

C. Streptococcus bovis

D. Streptococcus mitis

Compared with Enterococcus faecium, Enterococcus faecalis is how likely to demonstrate vancomycin resistance?

A. More likely

B. Equally likely

C. Less likely

D. Always resistant

Which Enterococcus species is more likely to demonstrate vancomycin resistance?

A. Streptococcus bovis

B. Enterococcus faecalis

C. Streptococcus sanguinis

D. Enterococcus faecium

Enterococcus species demonstrate which bile characteristic according to these notes?

A. Bile insoluble

B. Bile soluble

C. Bile dependent

D. Bile sensitive

Which infection is commonly caused by Enterococcus species?

A. Pharyngitis

B. Urinary tract infection

C. Dental caries

D. Impetigo

Enterococcus species can produce which cardiac infection?

A. Acute myocarditis

B. Pericarditis

C. Subacute endocarditis

D. Rheumatic carditis

Which additional infection is associated with Enterococcus species?

A. Sinus infection

B. Meningitis

C. Dental infection

D. Biliary tree infection

Why are Enterococcus species important causes of nosocomial infection?

A. Strong capsule production

B. High antibiotic resistance

C. Intracellular replication

D. Toxin-mediated disease

Enterococcus species are considered one of the leading causes of which type of infection in the United States?

A. Congenital infections

B. Community skin infections

C. Nosocomial infections

D. Tick-borne infections

Which oxygen-use classification describes Enterococcus species?

A. Obligate aerobes

B. Obligate anaerobes

C. Microaerophiles

D. Facultative anaerobes

Enterococcus species demonstrate which Gram-stain characteristic?

A. Gram-positive

B. Gram-negative

C. Acid-fast

D. Gram-variable

Which Gram-stain characteristic applies to all Streptococci according to these notes?

gram-_______

Streptococcus bovis biotype 1 is now known as which organism?

A. Streptococcus mutans

B. Streptococcus mitis

C. Streptococcus gallolyticus

D. Streptococcus sanguinis

A patient has left-sided endocarditis caused by Streptococcus viridans. Which antibiotic is listed as treatment?

A. Penicillin G

B. Azithromycin

C. Vancomycin

D. Metronidazole

A patient has left-sided endocarditis caused by Streptococcus bovis. Which antibiotic is listed as treatment?

A. Cefazolin

B. Penicillin G

C. Doxycycline

D. Clindamycin

Universal screening for maternal Group B Streptococcus colonization uses which specimens?

A. Vaginal and rectal cultures

B. Urine and blood cultures

C. Cervical and urine cultures

D. Vaginal and sputum cultures

Which childhood exanthem is known as second disease?

A. Measles

B. Scarlet fever

C. Rubella

D. Roseola

According to these notes, universal GBS screening is performed at approximately what gestational age?

A. 20–22 weeks

B. 24–26 weeks

C. 30–32 weeks

D. 36–38 weeks

Which two organisms are associated with underlying colorectal cancer?

A. S. pyogenes and MSSA

B. S. mutans and C. difficile

C. S. gallolyticus and C. septicum

D. GBS and S. pneumoniae

A patient develops acute lymphangitis. Which organisms are leading causes according to these notes?

A. S. pyogenes and MSSA

B. GBS and viridans streptococci

C. Pneumococcus and Enterococcus

D. S. mutans and C. septicum

Which childhood exanthem is classified as first disease?

A. Rubella

B. Measles

C. Scarlet fever

D. Roseola

Which childhood exanthem is classified as third disease?

A. Scarlet fever

B. Measles

C. Rubella

D. Erythema infectiosum

Which childhood exanthem is classified as fourth disease in these notes?

A. Roseola

B. Rubella

C. Scarlet fever

D. Scalded skin syndrome

Which organism causes the fourth childhood exanthem listed in these notes?

A. Staphylococcus aureus

B. Streptococcus pyogenes

C. Parvovirus B19

D. HHV-6

Which childhood exanthem is classified as fifth disease?

A. Roseola

B. Erythema infectiosum

C. Rubella

D. Scarlet fever

Which pathogen causes erythema infectiosum?

A. HHV-6

B. S. pyogenes

C. Parvovirus B19

D. S. aureus

Which pathogen causes roseola?

A. HHV-6

B. Parvovirus B19

C. S. pyogenes

D. S. aureus

How are Streptococcus and Enterococcus classified based on oxygen use?

A. Obligate aerobes

B. Facultative anaerobes

C. Obligate anaerobes

D. Microaerophiles

Streptococci and enterococci share which catalase characteristic?

A. Catalase variable

B. Catalase positive

C. Catalase negative

D. Catalase inducible

What is the most common cause of bacterial pharyngitis?

A. Streptococcus mutans

B. Enterococcus faecalis

C. Streptococcus pneumoniae

D. Streptococcus pyogenes

What distinguishes Streptococcus pyogenes from other streptococci in Lancefield classification?

A. Group A antigen

B. Group B antigen

C. Group D antigen

D. No Lancefield antigen

Which S. pyogenes virulence factor facilitates attachment to host cells through fibronectin?

A. M protein

B. Streptolysin O

C. F protein

D. Streptolysin S

How does streptococcal F protein promote host-cell attachment?

A. Binds cholesterol

B. Degrades complement

C. Activates plasminogen

D. Complexes with fibronectin

Streptococcal pyrogenic exotoxins are described as similar to toxins produced by which organism?

A. Corynebacterium diphtheriae

B. Staphylococcus epidermidis

C. Enterococcus faecalis

D. Streptococcus pneumoniae

Which S. pyogenes component produces the β-hemolytic pattern on blood agar?

A. Streptokinase

B. Streptolysin S

C. DNase-B

D. M protein

Which streptolysin is useful for serologic detection of a recent GAS infection?

A. Streptolysin S

B. Streptolysin B

C. Streptolysin O

D. Streptolysin A

Which test detects antibodies against streptolysin O?

A. CAMP test

B. Catalase test

C. Coagulase test

D. ASO test

Why may patients with GAS skin infections fail to develop elevated ASO antibodies?

A. Cholesterol inhibits streptolysin O

B. Skin lacks neutrophils

C. GAS loses M protein

D. Streptolysin S blocks antibodies

Where is the cholesterol that inhibits streptolysin O found according to these notes?

A. Plasma proteins

B. Skin lipids

C. Bacterial capsules

D. Red-cell membranes

Which description best distinguishes pyoderma from erysipelas?

A. Pyoderma causes strawberry tongue

B. Pyoderma causes systemic shock

C. Pyoderma primarily affects valves

D. Pyoderma is confined and purulent

A patient develops an acute raised red skin infection accompanied by fever and enlarged lymph nodes. Which diagnosis is most likely?

A. Erysipelas

B. Pyoderma

C. Scarlet fever

D. Rheumatic fever

Which clinical features are associated with erysipelas in these notes?

A. Bullae and hematuria

B. Fever and enlarged nodes

C. Cough and hemoptysis

D. Diarrhea and flushing

Which method can be used to detect Group A Streptococcus microscopically?

A. CAMP testing

B. Blood culture

C. Gram stain

D. ASO testing

Which GAS manifestation is described as easy to culture?

A. Rheumatic fever

B. Scarlet fever

C. Pharyngitis

D. Impetigo

If poststreptococcal glomerulonephritis is suspected after a skin infection, which antibody test should be performed?

A. Anti-DNase B

B. Anti-CAMP

C. Anti-capsular IgG

D. Anti-coagulase

Which culture medium is recommended for detection of maternal Group B Streptococcus?

A. MacConkey agar

B. Blood agar

C. Chocolate agar

D. Thayer-Martin agar

Streptococcus viridans demonstrates which hemolysis pattern?

A. Beta hemolysis

B. Gamma hemolysis

C. Alpha hemolysis

D. No hemolysis

Gram staining of sputum is described as a rapid diagnostic method for which pneumococcal diseases?

A. Otitis and sinusitis

B. Cellulitis and erysipelas

C. Pharyngitis and impetigo

D. Pneumonia and meningitis

Which movement disorder is a major Jones criterion for rheumatic fever?

A. Ataxia

B. Sydenham chorea

C. Hemiballismus

D. Resting tremor

Which skin manifestation is included in the Jones criteria?

A. Erysipelas

B. Impetigo

C. Erythema marginatum

D. Scarlet rash

Which finding is included among the Jones criteria?

A. Large bullae

B. Petechiae

C. Purulent abscesses

D. Subcutaneous nodules