Chapter 15: Streptococcus, Enterococcus and Other Catalase Negative Gram Positive Cocci

MLAB 2432 Microbiology

Streptococcus, Enterococcus and other Catalase Negative Gram Positive Cocci Learning Objectives

1. Describe the following characteristics common to the streptococci and related organisms: a. Gram stain morphology b. Catalase production

2. Categorize the species of streptococci based on the following classification systems: a. Lancefield ( serological) b. Brown (hemolysis)

3. Examine the clinical, epidemiological and laboratory findings associated with the following infections: a. Group A Streptococcus ( Streptococcus pyogenes) i. Pharyngitis ii. Erysipelas iii. Impetigo iv. Scarlet fever v. Necrotizing fascitis vi. Toxic shock syndrome

b. Group B Streptococcus ( Streptococcus agalactiae) i. Neonatal pneumonia ii. Neonatal meningitis iii. Postpartum infections iv. UTI’s v. Osteomyelitis

c. Group D Streptococcus ( Streptococcus bovis) i. Bacteremia associated with colon malignancy

d. Enterococcus i. UTI’s ii. Wounds iii. Mixed infections of the pelvis and abdomen

e. Viridans Streptococcus group i. Subacute bacterial endocarditis (SBE)

f. Streptococcus pneumoniae MLAB 2432 Microbiology

i. Pneumonia ii. Meningitis iii. Otitis media iv. Sinusitis

g. Streptococcus anginosus/miliieri group i. Deep wound infections ii. Abdominal infections

h. Abiotrophia species ( nutritionally variant streptococci) i. Endocarditis

4. Examine the clinical and laboratory findings associated with the following post streptococcal sequelae: a. Acute glomerulonephritis b. Rheumatic fever

5. Explain the principle of the following biochemical tests, including the interpretation of results: a. Bacitracin/SXT susceptibility b. CAMP test c. Rapid hippurate hydrolysis d. Bile-esculin hydrolysis e. Growth in 6.5% NaCl f. Optochin susceptibility g. Bile solubility h. Latex agglutination i. PYR= Pyrrolidonyl arylamidase test j. Catalase production k. Staphylococcal streak plate l. Vancomycin susceptibility m. Rapid Strep tests

6. Describe the significance of the following virulence factors produced by Group A Streptococcus: a. Pyrogenic exotoxins b. Streptolysin O c. Streptolysin S d. Hyaluronidase e. DNase f. Streptokinase g. M protein MLAB 2432 Microbiology

7. Differentiate between the following Streptococcaceae based on the gram stain and colony morphology: a. Group A Streptococcus b. Group B Streptococcus c. Group D Streptococcus d. Enterococcus e. Viridans Streptococcus group f. Streptococcus pneumoniae g. Groups C, F, and G Streptococcus

8. Sketch a flow chart to identify Streptococcus, including specific characteristics and or differential tests to identify each species.

4/6/2018