Gram Positive Algorithm

Front 1

Divide gram positive bacteria into what divisions?

(note: there are exceptions)

Back 1

Cocci and Bacilli

Front 2

What is unique about Mycobacterium?

Back 2

It is gram positive but doesn't belong in Cocci or bacilli.

Acid-fast.

Front 3

What is unique about Actinomyces and Nocardia?

Back 3

Gram positive but don't belong in either cocci and bacilli.

Branching filamentous growth (like fungi)

Front 4

What kind of growth do Actinomycoes and Nocardia have? (it is like what organism?)

Back 4

Branching filamentous growth (like fungi)

Front 5

Gram + Cocci

Further division?

Back 5

Catalase positive/negative

Positive: Staph
Negative: Strep

Front 6

Gram + Cocci, Catalase positive

Further division?

Back 6

Staph

Next decide whether it is coagulase Postive/negative
(+) S.aureus
(-) S.epidermis, S.saprophyticus

Front 7

Gram+, Cocci, catalase positive, coagulase positive

What organism?

Back 7

S.aureus

Front 8

Gram+, Cocci, catalase positive, coagulase negative

What organisms?

Back 8

S.epidermis
S.saprophyticus

Front 9

Gram+, Cocci, catalase positive, coagulase negative

S.epidermis
S.saprophyticus

How do you differentiate b/w the two?

Back 9

Novobiocin test.

Novobiocin sensitive: S.epidermis
Novobiocin resistance: S.saprophyticus

Front 10

Gram+, Cocci, catalase positive, coagulase negative, Novobiocin sensitive

Back 10

S.epidermis

Front 11

Gram+, Cocci, catalase positive, coagulase negative, Novobiocin resistance

Back 11

S.saphroyticus

Front 12

Gram+, cocci, catalase negative

Back 12

Strep

Front 13

Gram+, cocci, catalase negative = Strep

How do you further divide the streps?

Back 13

By thier hemolysis pattern (alpha, beta, random)

Front 14

Gram+, cocci, catalase negative, Beta hemolytic

What organisms?

Back 14

S.pyogenes
S.agalactiae (Group B strep)

Front 15

Gram+, cocci, catalase negative Beta hemolytic

S.pyogenes
S.agalactiae

How do you differeniate b/w the two?

Back 15

Bacitracin sensitive: S.pyogenes

Bacitracin resistant: S.agalactiae

Front 16

Gram+, cocci, catalase negative, alpha hemolytic

What organism?

Back 16

S.pneumoniae

S.mutans/S.intermedius

Front 17

Gram+, cocci, catalase negative, alpha hemolytic

Optocin susceptible vs. resistant

Back 17

Optocin susceptible: s.pneumoniae

Optocin resistant: S.mutans/S.intermedius

Front 18

Gram+, cocci, catalase negative, alpha, beta, or gamma hemolytic

Group D strep (what organisms?)

Back 18

E.faecalis
S.bovis

Front 19

Gram+, cocci, catalase negative, alpha, beta, or gamma hemolytic

NaCl resistant or susceptible?

Back 19

NaCl susceptible: S.bovis

NaCl resistant: E.faecalis

Front 20

Gram+, bacilli

Further divide into?

Back 20

Spore-forming vs. non spore-forming

Front 21

Gram+, bacilli, spore forming

Back 21

Bacillus
Clostridium

Front 22

Gram+, bacilli, non-spore forming

Back 22

Listeria
Corynebacterium

Front 23

Gram+, bacilli, spore-forming

Aerobic vs. Obligate anaerobe?

Back 23

Aerobic: bacillus

Obligate anaerobe: Clostridium

Front 24

Gram+, bacilli, spore-forming, Aerobic

Bacillus

Motile vs. non-motile

Back 24

Motile: B.cerus

Non-motile: B.anthracis

Front 25

Gram+, bacilli, spore-forming, Anaerobe

Clostridium

Motile vs. non-motile

Back 25

Motile: C.tetani, C.botulinum, C.difficle

Non-motile: C. perfringens

Front 26

Gram+, bacilli, non spore-forming

Motile vs. non-motile

Back 26

Motile: L.monocytogenes

Non-motile: C.diphtheraie

Front 27

What is unique about Listeria (L.monocytogenes)

Back 27

Only Gram positive which form Endotoxins