Streptococci

Question 1

What does STREPTOCOCCI look like on gram stain?

Answer 1

Gram +

Cocci

Chains

(Some diplo)

Question 2

General Strep characteristics

Answer 2

Facultative anaerobes

Catalase NEGATIVE

Carb antigens

Question 3

Describe the different zones of HEMOLYSIS

Answer 3

NO HEMOLYSIS (gamma)

ALPHA: cloudy green zone (green heme)

BETA: clear zone - lysis

Question 4

How do scientists classify strep?

Answer 4

Lancefield classification

detects carb antigens

A-O (all beta hemo except D)

Question 5

Where is Strep A found (And transmitted)?

Answer 5

sometimes skin and oropharynx

transmitted droplets

Question 6

What toxins allow Strep A to be invasive?

Answer 6

STREPTOLYSINS: hemolytic -> lyse cells

• O: oxygen labile
• S: stable in Oxygen

STREPTOKINASE:
-anti-coagulant

DNAse

Question 7

How does Strep A evade phagocytosis?

Answer 7

Hyaluronic acid capsule

M-proteins

• adherence
• resistance

Question 8

What toxins cause disease symptoms in Strep A?

Answer 8

SpeA, SpeB, SpeC
-proteases

Rash of scarlet fever

Strep TSS

Question 9

Tell me Scarlet about yo Fever

Answer 9

Happens sometimes with pharyngitis-tonsillitis

Cutaneous rash

Caused by SpeA/B/C
-superantigens

Question 10

Tell me about some invasive Strep A syndromes?

Answer 10

PUERPERAL fever: infection of uterus after childbirth

Acute PHARYNGITIS:

• strep throat
• headache, fever, chills, malaise

IMPETIGO: superficial skin infection

NECROTIZING FASCIITIS: flesh eating
-highly invasive

Question 11

What are the two sequel are of strep?

Answer 11

Rheumatic fever

Acute Glomerulonephritis

Question 12

Hey Rheuma, tell me about yo feva

Answer 12

Post strep throat

Heart and skin lesions

Joint pain

CROSS-REACTION of antibodies against heart and joints

Type II Hypersensitivity

PREVENTION: treat pharyngitis with penicillin

Question 13

What happens with acute Glomerulonephritis?

Answer 13

One week post skin (or throat) infection

Hematuria, edema, hypertension

Deposition of IMMUNE COMPLEXES

Type III Hypersensitivity

Question 14

How does one diagnose the Strep A?

Answer 14

Stain and Culture

+ cocci in chains

Beta hemolysis on blood plates

Sensitive to Bacitracin

Rapid Strep test - beads with anti-group A ab

Question 15

Is Strep A (pyogenes) sensitive to penicillin?

Answer 15

YES!!!!

ALL STREP A ARE sensitive TO PENICILLIN

Question 16

How would you diagnose Strep B

Answer 16

Bacitracin Resistant

Beta hemolytic (but smaller than A)

+ cocci in chains

Hydrolyze hippurate

Question 17

Where is Strep B found?

Answer 17

Vaginal and colonic flora

Major cause of neonatal infections
-septicemia, meningitis, pneumonia

Question 18

What are the ways Strep B usually presents?

Answer 18

1. EARLY ONSET
   - w/in first week
   - from vagina during birth
   - prevent by treating mom early
2. LATE ONSET
   - infant to infant spread
   - GOTTA CONTAIN THOSE BABAYS

Question 19

How would you treat Strep B?

Answer 19

PENAFRIKINCILLIN

Question 20

Does Group D Strep even exist?

Answer 20

Why yes

Enterococcus
Faecalis and faecium

Commonly in GI tract

UTI,
Wound infections
Sepsis

Question 21

What’s unique about Group D?

Answer 21

Can grow in high salt (6.5%)

Resistant to many antibiotics

USE VANCO

Question 22

Interesting facts about Strep Viridans

Answer 22

ALPHA hemolytic

Normal in mouth, nose, pharynx

Question 23

If Strep V. Is normally found in the mouth, what disease does it cause?

Answer 23

INFECTIVE ENDOCARDITIS

-first transient bacteremia

Adhere to preexisting lesions

-> VEGETATIONS

Question 24

What does Streptococcus PNEUMONIAE look like?

Answer 24

+ DIPLOCOCCI

Lancet-shaped
-short ends stuck together

Question 25

Any interesting facts about Strep Pneumonia?

Answer 25

No

Alpha hemolytic

OPTOCHIN SENSITIVE (Viridans is resistant)

BILE SOLUBLE (Viridans is not)

No animal reservoir

Question 26

How does Strep Pneumonia cause disease?

Answer 26

Source is usually mouth culture

Aspiration + fail to cough up -> pneumonia

Question 27

What are Strep Pneumonia’s secret weapons?

Answer 27

CAPSULE hinders phagocytosis

IgA PROTEASE degrades surface IgA

Question 28

Tell me about pneumococci’s pneumonia

Answer 28

Most frequent bacterial pneumonia

Cough; fever; chills; pleuritic pain; rusty sputum

Question 29

Who’s at risk for pneu’s pneu?

Answer 29

Use ab to fight off
-spleen also helps

Immunocompromised

Sickle cell anemia or splenectomy

Question 30

How does the lab diagnose pneumonia?

Answer 30

Examen sputum

Blood culture

Question 31

Any ways to prevent Strep Pneu?

Answer 31

1. Pneumovax 23
   - CAPSULAR POLYSACCHARIDE
   - old people and kids
   - T-cell INDEPENDENT
2. Prevnar 13
   - CONJUGATED VACCINE with diptheria
   - infants
   - T-cell DEPENDENT