Aerobes - Exam 8 Flashcards Preview

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Flashcards in Aerobes - Exam 8 Deck (49)
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1
Q

What type of anaerobe is described?

Can handle brief exposure to O2 and does not grow well at RT

A

Obligate anaerobe

2
Q

What type of anaerobe is described?

Incapable of growth after O2 exposure.

A

Strict obligate anaerobe

3
Q

What type of anaerobe is described?

Can grow in low O2 concentrations; most clinically significant anaerobes fall under this category.

A

Moderate obligate anaerobe

4
Q

What type of anaerobe is described?

Limited or scant growth in normal CO2 conditions.

A

Aerotolerant

5
Q

What type of anaerobe is described?

Grows with or without O2.

A

Facultative anaerobe

6
Q

What is an exogenous anaerobe?

A

An anaerobe that is not part of the normal flora that is causing disease.

7
Q

What is an endogenous anaerobe?

A

Normal flora that has spread away from its normal site and is causing infection.

8
Q

What are three recommended specimen types for anaerobes?

A

Blood, bone marrow, and aspirated material

9
Q

What are three not recommended specimen types for anaerobes?

A

Throat swabs, vaginal swabs, and voided urine

10
Q

When is testing for anaerobes necessary?

A

When the patient is suffering from a serious infection, recurring infections, and/or has a positive blood culture.

11
Q

What are 4 ways that anaerobic bacteria may be collected and transported?

A

In a blood culture bottle with a syringe, in a syringe, in a Port-a-Cul tube, and/or in a vacutainer specimen collector.

12
Q

What are the two ways that a vacutainer ensures O2 is not present?

A

There is a catalyst that precipitates O2 as H20 and a O2 detector that will present a color change in the presence of O2

13
Q

What is CDC blood agar and what is it used for?

A

CDC blood agar contains vitamin K and hemin and is used for recovering anaerobic bacteria.

14
Q

What is PEA agar and what is it used for?

A

PEA agar is phenylethyl alcohol agar and is used to recover gram positive organisms and inhibit gram negatives and swarming proteus - aerobically!

15
Q

What is CDC KV agar and what is it used for?

A

It is CDC agar with added kanamycin and vancomycin to inhibit the growth of facultative aerobic organisms - anaerobically!

16
Q

What is BBE agar and what is it used for?

A

BBE agar is Bacteroides Bile Esculin agar. Contains gentamicin and 20% bile. It is used to test for esculin hydrolysis and is useful for recovering Bacteroides species along with some species of the Fusobacterium and Enterococcus.

17
Q

What is egg yolk agar and what is it used for?

A

Egg yolk agar has the components to test for the utilization of lipase, lecithinase, and proteolysis. It is used for recovering Fusobacterium, Clostridium and Prevatella.

Note: lipase breaks down fats to create an oil on the agar surface

18
Q

What does enriched thioglycolate broth contain?

A

glucose, hemin and vitamin K

19
Q

What does a CCFA agar plate contain? What organism has a distinct appearance on this agar? Why is it used for this organism?

A

Cyclosporine, cefoxitin, and fructose. C. diff appears yellow on the agar - the agar helps inhibit intestinal flora.

20
Q

What are three methods of anaerobic incubation?

A

Anaerobic jar, gas pack pouch, and anaerobic chamber

21
Q

What are 5 macroscopic observations that may be made for anaerobic cultures?

A

Foul odor, blood present, black or necrotic tissue, sulfur granules and purulence

22
Q

What might you do differently when gram staining an anaerobic organism?

A

Leave the safranin on for longer

23
Q

What is the CDC KV plate specifically good for recovering?

A

Gram negative anaerobes

24
Q

What are some clues you may have an anaerobic bacteria on agar?

A

Pitting, crumb-like colonies, brown/black colonies with brick red fluorescence, molar tooth colonies, double zone of hemolysis, and swarming of the plate

25
Q

What must the diameter be for the SPS disc test to be considering sensitive?

A

> or = to 12mm

26
Q

Organism ID: Gram negative bacilli with rounded ends, grows on 20% bile, and is resistant to V, K and C.

A

Bacteroides fragilis group

27
Q

Organism ID: Gram negative pleomorphic bacilli with a fried egg colony morphology, grows on 20% bile, and is indole and lipase negative.

A

Fusobacterium mortiferum

28
Q

Organism ID: Gram negative pleomorphic bacilli (short and plump) with a fried egg colony morphology, grows on 20% bile and is indole variable.

A

Fusobacterium varium

29
Q

Organism ID: Gram negative pleomorphic, knob shaped bacilli, umbonate colony morphology, 20% bile growth is variable, indole and lipase are positive.

A

Fusobacterium necrophorum

30
Q

Organism ID: Gram negative spindle-shaped bacilli, breadcrumb-like colony morphology, growth on 20% bile is negative, indole is positive and the agar has started to green when bringing it into aerobic conditions.

A

Fusobacterium nucleatum

31
Q

Organism ID: Gram negative bacilli, obligate anaerobe, the colony is pitting the agar and is small and translucent, negative for growth on 20% bile, urease positive, nitrate reductase positive, resistant to V.

A

Bacteroides ureolyticus

32
Q

Organism ID: Gram negative bacilli, black/brown colonies with brick red fluorescence, asaccharolytic, grows on 20% bile, indole positive, resistant to K and C.

A

Porphyromonas

33
Q

Organism ID: Gram negative bacilli, black/brown colonies with brick red fluorescence, moderately saccharolytic, resistant to V and K, C variable.

A

Prevotella

34
Q

Organism ID: Gram positive bacilli, club shaped with some branched and unbranched, has a rough, molar tooth colony morphology, forms sulphur granules, grows best anaerobically, nitrate reductase positive, and esculin hydrolysis positive.

A

Actinomyces israelii

35
Q

Organism ID: Gram positive bacilli, smooth or rough colony types that becomes tan with age, aerotolerant, nitrate reductase positive, urease positive, and esculin hydrolysis variable.

A

Actinomyces naeslundii

36
Q

Organism ID: Gram positive bacilli, develops a red color of the CDC agar after time, is aerotolerant and microaerophilic, is nitrate reductase positive.

A

Actinomyces odontolyticus

37
Q

Organism ID: Gram positive bacilli, aerotolerant, catalase positive, urease positive, and nitrate reductase positive.

A

Actinomyces viscous

38
Q

Organism ID: Gram positive bacilli - small, strict obligate anaerobe, biochemically inactive.

A

Actinomyces meyeri

39
Q

Organism ID: Gram positive bacilli that look like birds in flight, small white colonies, grows better anaerobically, indole positive, catalase positive, nitrate reductase positive.

A

Propionibacterium acnes

40
Q

Organism ID: Gram positive bacilli that appear small and stubby, small grey, translucent colonies (very slow growth - pinpoint at 3 days), catalase positive, indole variable, nitrate reductase positive, and resistant to C.

A

Eubacterium lentum

41
Q

Organism ID: Gram positive bacilli that appear forked at the ends, aerotolerant, microaerophilic, negative for indole, catalase and nitrate reductase, positive for esculin hydrolysis.

A

Bifidobacterium dentium

42
Q

Organism ID: Gram positive bacilli that form long chains, appears alpha hemolytic, aerotolerant and microaerophilic, catalase negative.

A

Lactobacillus spp.

43
Q

Organism ID: Gram positive cocci, sweet and putrid odor, obligate anaerobe, indole negative, nitrate reductase negative, sensitive to SPS disc.

A

Peptostreptococcus anaerobius

44
Q

Organism ID: Gram negative cocci (looks like an over decolorized staph), catalase variable, resistant to V.

A

Veillonella spp.

45
Q

Organism ID: Spore forming Gram positive bacilli (chubby, long rods that look like Bacillus), double zone of hemolysis on plate, does not grow on 20% bile, aerotolerant, lecithinase positive, reverse CAMP positive, Nagler test positive, resistant to C.

A

Clostridium perfringens

46
Q

Organism ID: Spore forming Gram positive bacilli, medusa head colonies, will also swarm plate within 24-48 hours, positive for esculin hydrolysis.

A

Clostridium septicum

47
Q

Organism ID: Spore forming Gram positive bacilli, has a distinct “barnyard” smell and may grow yellow on CCFA, this organism is ID’d using direct detecting EIA methods

A

Clostridium difficile

48
Q

Organism ID: Spore forming Gram positive bacilli with subterminal spores, the gram stain is indicative and it is further ID’d using serological methods.

A

Clostridium botulinum

49
Q

Organism ID: Spore forming Gram positive bacilli with terminal spores (“tennis rackets”), will swarm on CDC, is lecithinase negative and lipase negative.

A

Clostridium tentani