gram positive pyogenic cocci

Question 1

Staphylococcus
aureus Morphology/Structure

Answer 1

Gram positive
pyogenic cocci

Question 2

Staphylococcus
aureus Modes of Transmission

Answer 2

Normal flora of
human mucosa:
nasal passages,
vagina, skin.
Usually enters
through a
wound.

Question 3

Staphylococcus
aureus Virulence Factors

Answer 3

Coagulase (prevents
phagocytosis and
concentrates toxins),
Capsule,
hyaluronidase, β
lactamase,
exfoliative toxins
(with SSS),
superantigens with
toxic shock
syndrome. Some
strains can kill
WBCs.

Question 4

Staphylococcus
aureus Disease/Symptoms

Answer 4

Cutaneous infections
(impetigo, boils,
folliculitis), more serious
is scalded skin
syndrome (SSS), Can
also cause septicemia,
meningitis, toxic shock
syndrome

Question 5

Staphylococcus
aureus Diagnostics

Answer 5

MSA plate - yellow,
ferments mannitol
Coagulase +
Catalase +

Question 6

Staphylococcus
aureus Immune Response

Answer 6

Superantigens
cause non-specific
activation of T
cells and
massive cytokine release, leading to
symptoms of toxic
shock syndrome.

Question 7

Streptococcus
pyogenes (also called
group A strep) Morphology/Structure

Answer 7

Gram positive
pyogenic cocci

Question 8

Streptococcus
pyogenes (also called
group A strep) Mode of Transmission

Answer 8

Some people
have as normal
flora.
Transmitted
though hand
contact with
nasal discharge
and skin contact
with impetigo
lesions

Question 9

Streptococcus
pyogenes (also called
group A strep) Virulence Factors

Answer 9

Streptolysins
(streptokinase), M
proteins, capsule,
hyaluronidase,
erythrogenic toxin
(Scarlet fever).

Question 10

Streptococcus
pyogenes (also called
group A strep) Diseases/Symptoms

Answer 10

Strep throat symptoms
red throat, tonsils,
swollen lymph,
Rheumatic fever, nausea
glomerulonephritis,
impetigo, scarlet fever,
necrotizing fasciitis

Question 11

Streptococcus
pyogenes (also called
group A strep) Diagnostics

Answer 11

Fever, patches of pus
in throat, swollen
lymph nodes, absence
of cough.
Rapid Antigen
Detection Tests
β hemolysis
Catalase -
bacitracin sensitive

Question 12

Streptococcus
pyogenes (also called
group A strep) Treatment/Prevention

Answer 12

Penicillin usually.
For necrotizing
fasciitis - drain and
remove dead skin

Question 13

Streptococcus
pyogenes (also called
group A strep) Immune Response

Answer 13

Erythrogenic toxin
acts as a
superantigens
cause scarlet
fever.

Question 14

Streptococcus
agalactiae (also called
group B strep) Morphology/structure

Answer 14

Gram positive
pyogenic cocci

Question 15

Streptococcus
agalactiae (also called
group B strep) Modes of Transmission

Answer 15

Normal flora of
up to 40% of
population
vagina, pharynx,
large intestine

Question 16

Streptococcus
agalactiae (also called
group B strep) Virulence Factors

Answer 16

Capsule, pore
forming toxin allows
entry into host

Question 17

Streptococcus
agalactiae (also called
group B strep) Diseases/Symptoms

Answer 17

Pneumonia
Majority of neonatal
meningitis

Question 18

Streptococcus
agalactiae (also called
group B strep) Diagnostics

Answer 18

Catalase –
β hemolysis
Strep B
bacitracin resistant

Question 19

Streptococcus
agalactiae (also called
group B strep) Prevention/Treatment

Answer 19

Strept B is tested for
in pregnant women
since it can cause
neonatal menengitits
treat with ampicillin or
amoxicilin

Question 20

Streptococcus
agalactiae (also called
group B strep) Immune Response

Answer 20

Natural microbe of
intestines and
vagina, but can
cause excessive
inflammation,
sepsis, and death
in infants and
elderly

Question 21

Streptococcus
pneumoniae
(Pneumococcus) Morphology/Structure

Answer 21

Gram positive
pyogenic cocci

Question 22

Streptococcus
pneumoniae
(Pneumococcus) Modes of Transmission

Answer 22

Normal flora of
human pharynx

Question 23

Streptococcus
pneumoniae
(Pneumococcus) Virulence Factors

Answer 23

Capsule, Produces
hemolysin and H2O2
which damages CNS
and immune system.
Major cause of
community acquired
pneumonia

Question 24

Streptococcus
pneumoniae
(Pneumococcus) Diseases/Symptoms

Answer 24

Pneumonia, can lead to
meningitis, sinusitis and
otitis media (ear
infection)

Question 25

Streptococcus pneumoniae (Pneumococcus) Diagnostics

Answer 25

Catalase - α hemolysis optochin sensitive

Question 26

Streptococcus pneumoniae (Pneumococcus) Prevention/Treatment

Answer 26

Routine vaccine for children, Prevnar vaccine recommeded to adults 65 and older. Can be treated with amoxicillin

Question 27

Streptococcus pneumoniae (Pneumococcus) Immune Response

Answer 27

Hemolysin and H2O2 cause damage CNS and immune system.

Question 28

Enterococcus faecalis (Streptococcus faecalis) Morphology/structure

Answer 28

Gram positive pyogenic cocci

Question 29

Enterococcus faecalis (Streptococcus faecalis) Modes of Transmission

Answer 29

Normal flora of GI tract. Commonly transmitted in hospitals through direct or passive contact.

Question 30

Enterococcus faecalis (Streptococcus faecalis) Virulence Factors

Answer 30

Plasmid encoded hemolysin and aggregation substance promotes host cell lysis, Suppresses action of lymphocytes, Produces biofilms

Question 31

Enterococcus faecalis (Streptococcus faecalis) Diseases/Symptoms

Answer 31

Urinary tract infections (UTI), endocarditis, bacteremia, necrotizing fasciitis (flesh eating bacteria)

Question 32

Enterococcus faecalis (Streptococcus faecalis) Diagnostics

Answer 32

Catalase - γ hemolysis (plasmid - α hemolysis) , differntiated from Streptococcus by resistance to dissolving in bile and high salts.

Question 33

Enterococcus faecalis (Streptococcus faecalis) Prevention/Treatment

Answer 33

Often resistant to penicillins and cephalosporin, often use vancomycin, however, now seeing VRE, use daptomycin

Question 34

Enterococcus faecalis (Streptococcus faecalis) Immune Response

Answer 34

Not common in healthy individuals. Usually a nosocomial infection where antibiotic use is high (leads to VRE).

Question 35

Staphylococcus aureus Prevention/Treatment

Answer 35

Incision and drainage of localized lesions. Treated with methicillin, unless MRSA, then treat with vancomycin.