Anaerobes Flashcards
1
Q
Aerotolerant
A
- 5% O2
- Actinomyces
- Bifidobacterium
- Clostridium
2
Q
Obligate Anaerobes
A
0% O2
- Prevotella
- Fusobacterium
- Bacteroides
- Lack superoxide dismutase
3
Q
Facultative Anaerobes
A
- Can grow in O2 but do not require it for metabolism
4
Q
Clostridium botulinum Characteristics
A
- Lipase positive (EYA) – a key marker for identification
- Gram stain: Gram-positive rod, obligately anaerobic, subterminal oval spores
- Natural reservoir: Soil and marine sediments world-wide
- Colony morphotypes: convex, raised or flat; round, irregular, entire or rhizoid borders
- Optimal temperature range: 4-37 C (type E as low as 4 C)
5
Q
BACTEROIDES FRAGILIS GROUP
A
* bile resistant
* resistant to kana, vanco, colistin disks
* most clinical isolates are catalase pos
* comprise 1/3 of clinical isolates
* most virulent (capsule)
* most antibiotic resistant
* Parabacteroides distasonis, merdae, goldsteinii
6
Q
PREVOTELLA SPECIES
A
- Isolated from oral and pelvic infections, abdominal and soft tissue
- Growth inhibited on BBE (but may turn agar black from hydrolysis of esculin if colonies plated directly)
- Resistant to kana, vanco, variable colistin
- Brick Red Fluorescense under UV
- Catalase usually negative
7
Q
PORPHYROMONAS SPECIES
A
- Brick red Fluorescence under UV
**Human species: - P. asaccharolytica (a-fucosidase- pos)
- P. gingivalis (trypsin pos)
- P. endodontalis
- P. uenonis (endodontalis, extra-oral)
- P. somerae (levii, human strain)
* Animal species: cultured from bite wounds - P. canoris, circumdentaria, cansulci, gingivicanis, gulae, levii, macacae, etc.
- Most are catalase positive
8
Q
FUSOBACTERIUM SPP
A
- S to kana, colistin disks; R to vanco
- indole positive; lipase negative
- slender rods with pointed ends
- several different colony types; subspecies
- Isolated from all types of infections and all areas of the body
- polymicrobial infections or single isolate
- LEMIERRE’S SYNDROME
- Or “post-anginal sepsis” (very rare) Occurs after prolonged or severe pharyngitis
- Septic thrombophlebitis with Fusobacterium necrophorum (probably from the mouth) associated with septic pulmonary emboli to the lungs
9
Q
“Bacteroides” ureolyticuslike
group
A
- Includes C.ureolyticus, Sutterella, other Campylobacter spp.,
- GNB sensitive to kana, colistin, R to vanco
- Small transparent/translucent colonies
- Pitting of agar is variable
- Most reduce NO3
10
Q
**Bilophila wadsworthia
A
- Original isolates from appendicitis
- Later from many other sources (chronic sinusitis, cholesteatom , pleural fluid, liver abscess, blood)
- Grows on BBE, black centers in colonies (H2S +)
- Catalase very positive !!!!!
- B-lactamase pos, resistant to many b-lactam agents
11
Q
GRAM-NEGATIVE COCCI
A
12
Q
“Anaerobic Streptococci”
A
- S. intermedius, S. constellatus, G. morbillorum previously classified as Peptococcus and Peptostreptococcus sp.
- Abiotrophia and Granulicatella (some grow better on anaerobe BA)
- initially may appear to be anaerobes
- eventually will grow in CO2
- Frequently recovered from abscess
- Resistant to metronidazole, most are
- susceptible to penicillin
13
Q
PROPIONIBACTERIUM ACNES
A
- Frequent skin contaminant in blood, csf cultures
- Occasionally pathogenic (shunts, implants, post-op cultures from eye)
- Relatively slow-growing
* ID based on pos rxns for catalase, indole, nitrate - Acne strains may be R to tetra and macrolides
- All strains R metronidazole
14
Q
**ACTINOMYCES SPECIES
A
- Many new species have been described,
- mostly from oral “mixed” infections.
- Important tests include pigment, catalase, nitrate, urease, esculin, carbohydrate fermentation, preformed enzymes
- Clinical isolates include A. israelii, A. odontolyticus, A. meyerii, A. turiscensis, A. neuii, and others
- Sulfur granules
15
Q
**CLOSTRIDIUM TETANI
A
- C tetani is found worldwide. Ubiquitous in soil, it is occasionally found in intestinal flora of humans and animals
- C.tetani is the cause of tetanus, or lockjaw.
- Spores are introduced into wounds by contaminated soil or foreign objects such as nails or glass splinters
- Morphology: long and slender; peritrichous flagella, no capsule, terminal located round spore(drum-stick apperance), its diameter greater than vegetative cell.
- Culture: obligate anaerobic; Gram(+); swarming occurs on blood agar, faint hemolysis.
- Biochemical activities: does not ferment any carbohydrate and proteins.
- Resistance: tolerates boiling for 60 min. alive after ten years in soil.
- Classification and Antigenic Types: C tetani is the only species. There are no serotypes
- Active immunity follows vaccination with tetanus toxoid
