Anaerobic Bacteria Flashcards
(41 cards)
What are obligate anaerobes
- Organisms unable to grow in presence of O2
- Require low reduction/oxidation potential (Eh)
What are facultative anaerobes and give examples
- Organisms which grow under aerobic or anaerobic conditions, e.g. E. coli, staphylococci, streptococci
What are obligate aerobes and give examples
- Organisms unable to grow in absence of O2, e.g. Pseudomonas, Neisseria
What are microaerophiles and give examples
- Organisms that require a small amount of O2 i.e. less than normal atmospheric level of 20% v/v, e.g. Campylobacter, Helicobacter
What are capnophiles and give examples
- Organisms that require 5 – 10% CO2 for growth, e.g. Brucella, Capnocytophaga
What are some methods for the cultivation of anaerobes
- Anaerobic Jars
- Anaerobic Cabinets
- Roll Tube Techniques
- Robertons cooked meat medium
How does the vacuum/replacement method for anaerobic jars work
Remove air with vacuum pump to replace the atmosphere with a gas mix including a palladium catalyst
How does the gas-generating sachets method for anaerobic jars work
‘Anaerogen’ sachets - O2 absorbed/CO2 produced/ no catalyst need/no water added
What air composition is used for vacuum anaerobic jars
80% N2, 10% H2, 10% CO2
How do anaerobic cabinets work for anaerobe cultivation
- Complete working chamber for anaerobes
- Contains atmosphere of 80% N2, 10% H2, 20% CO2
- Pass materials in and out via air lock
Name 3 types of clinically important anaerobes (gram positive genera)
- Cocci - peptostreptococcus
- Spore-forming rods - Clostridium
- Non-sporing rods - propionibacterium, eubacterium, actinomyces
Name 3 types of clinically important anaerobes (gram negative genera)
- Cocci - veillonella
- Rods and Filaments - Bacteriodes, Fusobacterium, Porphyromonas, Prevotella, Campylobacter
- Spirochaetes - spirochaeta, Treponema
What types of bacteria can be found in/cause dental alveolar/periapical abscesses
Oral streptococci and many oral anaerobes - obligate anaerobes are predominant here
What is osteomyelitis and what types of bacteria are often responsible
- Rare disease causing inflammation of the jaw bone cavity
- Anaerobic gram negative rods and streptococcus spp.
What is chronic marginal gingivitis and what types of bacteria are often involved
- Inflammation confined to the soft tissues of the gingiva as a result of dental plaque accumulation - no particular species of bacteria involved
What is Acute Ulcerative Gingivitis (AUG) and what bacterial species are often involved
- Grey gingival pseudomembrane, which is easily removed to reveal a bleeding area and destruction of the interdental papillae
- Spirochaetes, prevotella intermedia and Fusobacterium spp.
What is periodontitis and what bacteria are often associated with it
- Gingival inflammation extending to the deeper tooth supporting structures with destruction of periodontal ligament and alveolar bone
- Porphyromonas gingival, prevotella intermedia, Actinobacillus actinomycetemcomitans, Capnocytophaga spp. etc
What is pericoronitis and what bacteria are often associated with it
- Inflammation of the soft tissues the surround the crown of a partially erupted tooth esp. mandibular third molars
- Oral anaerobes including P,. intermedia and fusobacterium nucleatum
What is Peri-implantitis and what bacteria are associated with it
- Inflammation around implant systems that replace missing teeth
- Oral anaerobes esp. P. gingivalis and P. intermedia
What is actinomycosis and what bacteria is associated with it
- Formation of a chronic granuloma with swelling
- In chronic cases multiple discharging sinuses observed
- Actinomyces Israelii
What is Sialadenitis and what bacteria are associated with it
- Infection of the salivary glands
- Streptococcus spp., staphylococcus aureus and gram negative anaerobes
Describe the general features of infection with non-spring anaerobes
- Occurs at various body sites
- Commonly polymicrobial
- Often found in abscesses and wound infection
- May be associated with foul-smelling pus or discharge
- Good anaerobic isolation techniques are needed for diagnosis
- Treatment may include surgical drainage and antibiotics
What type of bacteria are clostridium
- Gram positive large anaerobic rods
What does the production of endospores allow for clostridium bacteria
enable organisms to survive adverse conditions e.g. soil and on skin
