Organism gram staining

Question 1

Gram positive cocci, catalase positive (aerobe)

Answer 1

Staphylococcus

Question 2

Gram positive cocci, catalase negative (aerobe)

Answer 2

Streptococcus

Question 3

Gram positive cocci, catalase positive, coagulase positive

Answer 3

S. Aureus

Question 4

Gram positive cocci, catalase positive, coagulase negative

Answer 4

S. Saphrophyticus, S. Epidermidis

Question 5

Gram positive bacilli

Answer 5

Listeria, cornyebacterium, clostridium

Question 6

Gram positive bacilli aerobes

Answer 6

Listeria, cornyebacterium

Question 7

Gram positive bacilli anaerobes

Answer 7

Clostridium

Question 8

Gram positive branching filaments

Answer 8

Nocardia (weakly AFB positive, Actinomyces

Question 9

Gram positive cocci, catalase negative, alpha haemolytic (partial)

Answer 9

Viridans strep (S Mitis, S Mutans), S pneumoniae (encapsulated)

Question 10

Gram postive cocci, catalase negative, beta haemolytic (full haemolysis)

Answer 10

S pyogenes (Group A), S aglactiae (Group B)

Question 11

Gram positive cocci, catalase negative, y-haemolytic (no haemolysis)

Answer 11

Enterococcus (Group D, E faecalis and E Faecium),

Question 12

What does gram positive mean

Answer 12

Bacterial cell wall of these organisms have thick peptidoglycan layers, which take up the purple/violet stain

Question 13

Gram negative bacteria why negative

Answer 13

Thin peptidoglycan later, LPS layer

Question 14

Gram negative diplococci

Answer 14

N. meningitidis, N. gonorrhoaea, Moraxella

Question 15

Gram negative cocco-bacilli

Answer 15

H. influenzae, B. pertussis

Question 16

Gram negative bacilli

Answer 16

Shigella, Yersinia, Pseudomonas, Citrobacter, Serratia, E.Coli. Klebsiella, Enterobacter, Legionella, Salmonella, Proteus, Trepnema pallidum

Question 17

Gram negative comma shaped

Answer 17

C. jejuni, V. Chlorae, H. Pylori (urease producing)

Question 18

Toxins produced by Staph

Answer 18

Exfoliative Toxin A (skin)
Toxic Shock Synsroke Toxin 1
Haemolysin Alpha (virulence factor, helps binding to target cell)
Panton-Valentine Leukodin (necrotising pneumonia)