U2.2.1 Gr (+) Cocci : Streptococcus Flashcards
Streptococcus & Enterococcus
Family
Streptococcacee
Streptococcus & Enterococcus
Morphology
Gram (+) cocci in chains
Streptococcus & Enterococcus
Morphology of S. pneumoniae
diplococci
Streptococcus & Enterococcus
Select all that apply
Generalities of Streptococcus
1. Facultative Anaerobes
2. Non motile and Non-sporeformers
3. Catalase Positive
4. Some may require 5-10% CO2 for growth
1,2,4
Catalase Negative
Streptococcus & Enterococcus
Select all that apply
Generalities of Streptococcus
1. Resistant to Vancomycin
2. Require enriched or supportive media (BAP)
3. Many members are normal flora and not opportunistic
4. Causes a wide spectrum of infections
2, 4
Susceptible to Vancomycin, 3 - are opportunistic
3 types of classification of Streptococci and Enterococci
- Sherman’s (Physiologic)
- Rebecca Lancefield Classification
- Brown’s Classification
Sherman’s Classification
Grows at 37C; Pus forming
Pyogenic
Sherman’s Classification
Grows at 37C and 45C
Viridans
Sherman’s Classification
4 species classified as viridans
S. salivarius, S. mutans, S. mitis, S, sanguis
Sherman’s Classification
Grows at 10C and 37C
Lactic
Sherman’s Classification
Grows at 10C, 37C and 45C
Enterococcal
Classification of Streptococci & Enterococci
Basis: Grouped based on the cell wall polysaccharide (Common C Carbohydrate) Antigen and cell wall teichoic acids
Rebecca Lancefield Classfication
Rebecca Lancefield Classfication
Clinically significant that has cell wall polysaccharide
A, B, C, F and G
Rebecca Lancefield Classfication
Clinically significant that has cell wall techoic acids
D and Enterococcus
Classification of Streptococci & Enterococci
Basis: Hemolytic Patterns
Brown’s Classification
Brown’s Classification
Species that show Beta Hemolysis
Group A, B, C, F & G
Brown’s Classification
Species that show Alpha Hemolysis
S. pneumoniae
Brown’s Classification
Species that show Gamma Hemolysis
Group D Enterococcus
Brown’s Classification
Species that show alpha-prime hemolysis
Viridans
Group A Streptococcus
Group A Beta Hemolytic Streptococcus & colonizers skin & throat
Streptococcus pyogenes
Group A Streptococcus
Streptococcus pyogenes
- antigenic structure [2]
Gr (+) Cell Wall (Peptidoglycan) and Presence of M Protein
Grp A Streptococcal Infections
Most common manifestation includes tonsilitis and pharyngitis
Bacterial Pharyngitis
Grp A Streptococcal Infections
Strep Throat
Bacterial Pharyngitis
Grp A Streptococcal Infections
resembles
pharyngitis with Skni rash.” desquamation of skin;
“strawberry tongue”
Scarlet Fever
Grp A Streptococcal Infections
production of ____ toxin is present in scarlet fever
eryhtrogenic toxin
Grp A Streptococcal Infections
T/F Group A Streptococcal infections also causes to impetigo cellulitis & erysipelas.
T
Grp A Streptococcal Infections
“Flesh Eating Disease”
Necrotizing Fascitis
Grp A Streptococcal Infections
“Suppurative Fasciitis”, Hospital Gangrene, Necrotizing Erysipelas
Necrotizing Fascitis
Grp A Streptococcal Infections
Necrosis of skin, subcutaneous fat and
fascia
Necrotizing Fascitis
Grp A Streptococcal Infections
caused by Pyogenic Exotoxin A
Streptococcal Toxic Shock Syndrome
Grp A Streptococcal Infections
Includes Acute Rheumatic Fever and Rheumatic Heart Disease
& Acute Glomerulonephritis
Poststreptococcal Sequelae
Grp A Streptococcal Infections
Drug of Choice
Penicillin or Erythromycin
Pathogenic Determinants of Grp A Strep (Extracellular)
causes fever; skin rash of scarlet fever; Blood brain alteration; organ damage
Erythrogenic/Pyogenic Toxins A,B,C
Pathogenic Determinants of Grp A Strep (Extracellular)
protease implicated in flesh eating streptococci
Exotoxin B
Pathogenic Determinants of Grp A Strep (Extracellular)
causes lysis of blood clots; spread of infection
Streptokinase
Pathogenic Determinants of Grp A Strep (Extracellular)
caused by mucoid colonies (capsulated); antiphagocytic
M Protein
Group B Streptococcus
Normal Flora of GI Tract, Pharynx and Vaginal Tract
AR
Streptococcus agalactiae
Pathogenic Determinants of Grp A Strep (Extracellular)
induce proliferation of host I-lymphocytes
Superantigens
Group B Streptococcus
Grp B Beta Hemolytic Clinically important species
Streptococcus agalactiae
Pathogenic Determinants of Grp A Strep (Extracellular)
mediates epithelial cell attachment
Protein F
Group B Streptococcus
causes Mastitis in Cattle and Invasive Disease in Newborns
Streptococcus agalactiae
Group B Streptococcus
Antigenic Structure of Streptococcus agalactiae
Group BSpecific Antigen (acid stable)
Group B Streptococcus
Select All
Neonatal Infections caused by Grp B Streptococcus
1. Pneumonia
2. Endocarditis
3. Meningitis
4. Bacteremia leading to Death
1, 3, 4
Group B Streptococcus
T/F Grp B Streptococcus causes puerperal sepsis and maternal septicemia
T
Group B Streptococcus
Select all that apply
Adult Infections
1. Skin Infections
2. UTIs
3. Bacteremia
4. Septicemia
5. Endocarditis
6. Endometritis
7. Cardiomegaly
1, 2, 3, 5, 6
Group B Streptococcus
Drug of Choice
Penicillin
Group B Streptococcus
Select all
Pathogenic Determinants
1. Streptolysin O
2. Hemolysin
3. Capsule
4. CAMP Factor
2, 3, 4
Group B Streptococcus
Select all
Pathogenic Determinants
1. DNASE
2. RNASE
3. Hyalurodinase
4. Protease
1, 3, 4
Streptococcus
Ability to grow in 40% bile and Hydrolyze Esculin
Group D Streptococcus and Enterococcus
Group D Streptococcus
Two subgroups
- Enterococcus
- Non-enterococcus
Group D Streptococcus
Gr(+) Cocci that are normal flora of GI tract of animals and humans
Enterococcus
Group D Streptococcus
All produce Group D Antigen
Enterococcus
Group D Streptococcus
Able to Grow under extreme conditions
Enterococcus
Group D Streptococcus
Clinically significant Species of Enterococcus
E. faecalis, E. faecium, E. durans and E. avium
Group D Streptococcus : Enterococcus
T/F Enterococcus is susceptible to Penicillin G
F, resistant
Group D Streptococcus : Enterococcus
Drug of Choice
Combination of cell wall inhibitor such as vancomycin or ampicillin and an aminoglycoside such
as gentamicin or streptomycin
Group D Streptococcus : Enterococcus
Select All
Pathogenic Determinants
1. Hyalurodinase
2. able to grow in extreme conditions
3. Gelatinase
4. Cytolysin
5. Surface Adhesin protein
2, 3, 4, 5
Group D Streptococcus : Enterococcus
Select all that apply
Infections
1. UTI
2. Endocarditis
3. Septic Arthritis
4. Bacteremia
1, 2, 4
Group D Streptococcus : Enterococcus
Select all that apply
Infections
1. Wound infections
2. Intraabdominal abscesses
3. Pneumonia
4. Osteomyelitis
1, 2
Group D Streptococcus
Group D Streptococcus : Non Enterococci species
Streptococcus bovis group
Group D Streptococcus : Non-Enterococci
High association with Colon Cancer
Streptococcus bovis group
Group D Streptococcus
Agents of bacteremia, septicemia and endocarditis
Non-enterococci Streptococcus bovis group
Group C Streptococcus
Select all that apply
Infections
1. Endocarditis
2. Severe pharyngitis
3. Pneumonia
4. Cellulitis
5. Abscess
2, 3, 4, 5
Group D Streptococcus : Non Enterococci
examples of Streptococcus bovis group
S. equinus, S. gallolyticus
Group C Streptococcus
Examples of Group C
DEEZ
S. equi
Streptococcas equsimilis
Streptococcus zooepidemicus Streptococcus dysagalactiae
Group C Streptococcus
Species that causes strangles among horses
S. equi
Miscellaneous Lancefield Groups
Group of Streptococcus anzinosus
Group F and G
Genus Streptococcus
usually Normal Flora of oropharynx
Viridans Streptococci
Miscellaneous Lancefield Groups
Causes bacteremia and liver abscess
Streptococcus anzinosus
Miscellaneous Lancefield Groups
Culture used for Group F & G
Honeysuckle Odor
Genus Streptococcus
do not possess Polysaccharide Component
Viridans Streptococci
Miscellaneous Lancefield Groups
Normal flora of the GI tract, vaginal tract and oropharynx
Group G
Genus Streptococcus: Viridans Strep
Select all
Viridans Streptococci
1. S. mutans
2. S. intermedius
3. S. mitis
4. S. sanguis
5. S. constellatus
6. S. equi
7. S. salvarius
2, 3, 4, 5, 7
Viridans Streptococcus
Select all
Infections
1. Subacute Bacterial Endocarditis
2. Pneumonia
3. Dental Caries
4. Hepatomegaly
5. Abscess and bacteremia
6. Gingivitis
1, 3, 5, 6
Viridans Streptococcus
Select all
Pathogenic Determinants
1. Polysaccharide Capsule
2. Cytolysin
3. Hyalurodinase
4. Glucans
5. Dextrans
1, 2, 4, 5
Streptococcus
Diplococcus or Pneumococcus
Streptococcus pneumonia
Streptococcus
Gr(+) cocci in pairs
S. pneumoniae
Streptococcus
May be a normal flora of the Upper Respiratory Tract of pre-school children
Streptococcus pneumonia
Streptococcus pneumoniae
Select all
1. Bacterial Pneumonia (Lobar Pneumonia)
2. Septicemia
3. Meningitis
4. Otitis media
5. Bacteremia
6. Sinusitis
1, 3, 4, 5, 6
S. pneumoniae
Select All
Virulence Determinants
1. Polysaccharide Capsule
2. Pneumolysin
3. IgE protease
4. Hyalurodinase
5. IgA protease
6. DNAse
7. Neuraminidase
1, 2, 4, 5, 7
Streptococcus like organisms
Nutritionally Variant Streptococci
Abiotrophia and Granulicatella
Streptococcus like organisms
viridans streptococci that require cysteine or vitamin B6
Abiotrophia and Granulicatella
Streptococcus like organisms
satelliting streptococci
A. defectiva
Streptococcus like organisms
satelliting streptococci, thiol requiring or pyridoxal requiring streptococci
A. adjacens and A. defective,
G. adiacens
Strep-like Organisms
Common airborne organism
Aerococcus
Strep-like Organisms
Causes endocarditis, wounds & abscesses
Gemella
Strep-like Organisms
previously Group N and causes UTI & Endocarditis
Lactococcus
Strep-like Organisms
an opportunistic pathogen found in plant surfaces, vegetables and milk products
Leuconostoc
Strep-like Organisms