Bacterial Diseases of Humans Caused by Staphylococci, Streptococci and Anaerobes

Question 1

Staphylococci 3 features

Answer 1

Gram +ve cocci
catalse +ve
facultative anaerobes

Question 2

staphylococcal diseases are … and can cause disease in …., they produce many … and …. which aid in

Answer 2

invasive
virtually any tissue and organ
enzymes and toxins
pathogenicity

Question 3

Toxic shock syndrome is caused by strains of …. that produce …. it occurs in … or after …
symptoms include….
it stimulates extensive ….
and can lead to ….

Answer 3

s.aureus
exotoxin
surgical wounds
boils
fever, rash, exfoliation of skin
non-specifc immune response
organ failure and death

Question 4

Strepococcal diseases:

4 properties

Answer 4

gram +ve
facultative anaerobes
catalse -ve
grouped on basis of cell carbohydrate surface antigens

Question 5

4 diseases caused by streptococcal pyogens

Answer 5

impetigo cellulitus

more serious: rheumatic fever, necrotising fasciitis

Question 6

transmission of s.pyogens is usually through

Answer 6

respiratory droplets

Question 7

Exotoxin A from S.pyogens:

Answer 7

superantigen that stimulates production of high levels of cytokines which damage blood vesselendothelial cells so tissues can be damaged by lack of blood

Question 8

exotoxin B produces .. that …

Answer 8

protease destroys tissues

Question 9

necrotising fasciitis occurs when an invasive … enters a … membrane or …. after minor … or ….. It causes the destruction of the … covering …

Answer 9

s.pyogene
mucous
skin
trauma
surgery
sheath
skeletal muscles

Question 10

Treatment of necrotising fasciitis

Answer 10

Penicillin G and surgical debridement of dead and dying tissue

Question 11

S.pneumoniae causes localised and systemic infections such as (3)

Answer 11

ear infections
meningitis
pneumonia

Question 12

Group B streptococci causes illness in..
may cause…
it is sensitive to

Answer 12

newborn babies
elderly
pregnant people
people with other diseases
aseptic abortion
penicillin

Question 13

viridians group streptococci, infections usually occur in hosts who are… the bacteria enter the blood and adhere to … …. … and cause ….. May also cause …. most are sensitive to

Answer 13

immunocompromised
abnormal cardiac valves
endocarditis
gingivitis
penicillin

Question 14

Tetanus is caused by … which are gram … …, they form … and are …. anaerobes

Answer 14

clostridium tetani
+ve rods
endospores
obligate

Question 15

Tetanus endospores are widespread in (3)
transmission is usually via …
endospores germinate in …. if … is low enough
as bacteria die they release the neurotoxin…

Answer 15

soil, dust, animal, faeces
skin wounds
wounds oxygen
tetanospasmin

Question 16

In tetanus, toxin is carried to the … , it binds to … which leads to overactivity of …. This results in….
treatment is … and …

Answer 16

CNS
neurones
motor neurones
spams, rigidity, lock jaw
penicillin muscle relaxant

Question 17

Botulism is caused by ….. , gram +ve (shape), obligate …
endosopres are widespread in … and …
most common source of infection is ….
spores germinate in … environment
syptoms (4)
Treatment is with …. which are specific to the …

Answer 17

clostridium botulinum
rods
anaerobe
soil and sediments
improperly heated preserved food
anaerobic
blurred vision, mucle weakness, nausea, vomiting
antibodies toxin

Question 18

clostridium difficile: main cause of (2)

they cause rapid destruction of the …, making an early … very important

Answer 18

diarrhoea pseudomembranous colitis
gut
diagnosis

Question 19

clostridium perfringens causes ....
typically grows in...
spores produce...
CP can also cause...
at the sight of...
the onset is sudden and ...
inflammation begins at

Answer 19

food poisoning
poorly prepared or reheated meals
enterotoxin
gas gangrene
trauma/surgical wound
dramatic
site of infection