Article 2: Major Groups of Disease-Causing Bacteria (Article) Flashcards Preview

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Flashcards in Article 2: Major Groups of Disease-Causing Bacteria (Article) Deck (35):
1

Aerobic Gram-Positive Rods (3 important genera)

Bacillus, Corynebacterium, and Listeria

2

Two medically important genera that produce spores

Bacillus and Clostridium

3

Bacillus anthracis (Morphology, Spore Production, Motility, Unique Properties)

Large: end-to-end chains, Yes, No, Poly-D-glutamic acid capsule; spores

4

Bacillus cereus (Morphology, Spore Production, Motility, Unique Properties)

Large, Yes, Yes; 50% of strains, Spores

5

Corynebacterium diphtheriae (Morphology, Spore Production, Motility, Unique Properties)

Small and narrow, No, No, Pleomorphic; Chinese Characters (divides via snapping fission)

6

Listeria monocytogenes (Morphology, Spore Production, Motility, Unique Properties)

Small, No, Yes; tumbling motion, Grows at 3-4 degrees C; grows intracellulaly

7

Anaerobic Spore-Forming Gram-Positive Rods

Clostridium (only genus)
-Produce endospores to survive adverse conditions
e.g. C. botulinum, C. tetani, C. perfringens, C. difficile

8

Clostridium botulinum

-Fastidious spore-forming gram-positive rod shaped organism
-Production of a NEUROTOXIN results in disease (i.e. flaccid paralysis)
-Commonly isolated in SOIL and WATER

9

Clostridium tetani

-Tennis rackt/drumstick appearance due to terminal ENDOSPORE
-Difficult to grow in vitro due to extreme OXYGEN SENSITIVITY
-Production of a NEUROTOXIN (tetanospasmin) causes spastic paralysis (i.e. lockjaw, arching of back, and respiratory muscle spasms)
-Commonly found in SOIL

10

Clostridium perfringens

-Hemolytic and produces several toxins (alpha, beta, epsilon, and iota)
-Grows rapidly in tissue and in culture
-NOT motile (unlike other Clostridia)
-Cellulitis, suppurative myositis, gas gangrene, food poisoning

11

Clostridium difficile

-Associated with prior antibiotic use and other chemotherapies
-Extremely sensitive to oxygen
-WATERY DIARRHEA

12

Gram-Positive Cocci

Staphylococcus, Streptococcus, and Enterococcus

13

Staphylocci

Catalase POSITIVE and grow in large clusters
-Grow in media with up to 10% salt
-Aerobic or anaerobic
-Found on skin and mucous membranes

14

Streptococci

Catalase NEGATIVE and grow in chains

15

Enterococcus

Catalase NEGATIVE and is in the Lancefield D group

16

Staphylococcus aureus (Hemolysis, Catalase, Coagulase/Mannitol fermentation, Novobiocin)

Beta or gamma, Positive, Positive/Positive, Sensitive

17

Staphylococcus epidermidis (Hemolysis, Catalase, Coagulase/Mannitol fermentation, Novobiocin)

Gamma, Positive, Negative/Negative, Sensitive

18

Staphylococcus saprophyticus (Hemolysis, Catalase, Coagulase/Mannitol fermentation, Novobiocin)

Gamma, Positive, Negative/Negative, Resistant

19

S. aureus

-Coagulase POSITIVE
-Most pathogenic and causes several diseases (e.g. food poisoning, toxic shock syndrome, scalded skin syndrome, impetigo/bullous impetigo, folliculitis, furuncles or boils, carbuncles, bacteremia and endocarditis, pneumonia and empyema, osteomyelitis, and septic arthritis)
-Produces a golden pigment

20

S. epidermidis

-Coagulase NEGATIVE
-ubiquitous inhabitant of human skin
-forms biofilm on implanted medical devices (catheters, prosthetic joints, and heart valves)

21

S. saprophyticus

-Coagulase NEGATIVE
-novobiocin resistant
-Second most common cause of UTI in sexually active young women (ages 13 to 40 y.o.) following E. coli

22

Streptococcus pyogenes (Lancefield grouping, Hemolysis, Biochemical tests)

A (GAS), Beta, Sensitive to Bacitracin (A disc)

23

Streptococcus agalactiae (Lancefield grouping, Hemolysis, Biochemical tests)

B (GBS), Beta usually; sometimes Gamma, CAMP test positive; hippurate hydrolysis

24

Streptococcus pneumoniae (Lancefield grouping, Hemolysis, Biochemical tests)

Nongroupable, Alpha; Viridians group, Soluble in bile; Sensitive to Optochin (P disc)

25

Streptococcus pyogenes

Uniquely sensitive to Bacitracin compared to other beta hemolytic streptocci
Wide variety of diseases:
-Pharyngitis "strep throat", Scarlet fever, Impetigo, erysipelas, cellulitis, necrotizing fasciitis, Streptococcal Toxic Shock Syndrome, Bacteremia, Sepsis, Cross-reactive antigen or immune complex disease (e.g. Rheuamtic fever, Acute glomerulonephritis)

26

Streptococcus agalactiae

Produces diffusible heat stable factor (CAMP factor)
Early onset disease, Late onset disease, Adult diseases (UTIs and compromised adults)

27

Streptococcus pneumoniae

LANCET-SHAPED or bull-shaped diplococcus

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Enterococcus

Catalase NEGATIVE

29

Enterococcus faecalis and faecium

Both found in the GI or GU tract commonly
-Cause UTI, bacteremia, endocarditis, intra-abdominal abscesses

30

Gram-Negative Bacteria: Gram-Negative Cocci

Neisseria
-Two important species (N. meningitidis and N. gonorrhoeae)
-Kidney bean-shaped; look like a coffee bean when two are lined up with their flattened sides

31

Neisseria gonorrhoeae (Shape, Oxidase reaction, Acid via oxidation of carbohydrate, Media Requirements)

Diplococcus, Positive, Glucose only, Chocolate and Thayer-Martin agar

32

Neisseria meningitidis (Shape, Oxidase reaction, Acid via oxidation of carbohydrate, Media Requirements)

Diplococcus, Positive, Glucose and Maltose, Blood or chocolate agar

33

Enteric Gram-Negative Rods

Enterobacteriaceae:
-Eschericia (rod shaped)
-Salmonella (rod shaped)
-Shigella (rod shaped)
-Yersinia (rod shaped)

Non-Enterobacteriaceae:
-Vibrio (comma shaped rod)
-Campylobacter (comma shaped rod or S-shaped rod or corkscrew)
-Helicobacter (spiral shaped rod)
-Bacteroides (rod shaped; ONLY OBLIGATE ANAEROBE)

34

Non-Enteric Gram-Negative Rods

Klebsiella (found in GI tract)
Haemophilus and Legionella (respiratory pathogens)
Francisella (ticks, black flies, rabbit skinning)
Pasteurella (animal bites)
Brucella (unpasteurized/imported dairy products)
Yersinia pestis (flea bites)
Rickettsia (tick bites)

35

What two Non-Enteric Gram-Negative Rods are opportunistic infections (require a defect in the patients' immune functioning)?

Pseudomonas and Kelbsiella