1.2.1 Nocardia Flashcards
What is the gaseous composition of Nocardia?
Obligate aerobe
What catalase positive or negative is Nocardia?
Positive
What is the gram stain of Nocardia and it’s appearance?
Gram-positive filamentous rods
Is it weakly acid fast?
Yes
Nocardia’s peptidoglycan contains?
m-DAP (meso-diaminopimelic acid)
Arabinose
Galactose
(MAGazine)
What individual does Nocardia usually infects?
Immunocompromised patients
What are the 2 types of Filamentous forms of Nocardia?
Substrate hyphae
Aerial hyphae
A filamentous forms or formed branches filaments of hyphae that extend along the agar surface or into the agar
Substrate hyphae
Produced or formed branched filaments or hyphae that extend into the air
aerial hyphae
What is the life cycle of Nocardia?
- Germination
- Substrate hyphae
- Aerial hyphae
- Coiling
- Septation
- Spore mutation
- Spore release
- Free spore
What are the Most commonly encountered Nocardia species?
asteroides
brasiliensis
farcinica
nova
What are the human pathogens of Nocardia spp.?
asteroides
brasiliensis
Less commonly encountered Nocardia are?
otitidiscaviarum
pseudobrasiliensis
abscessus
africana
transvalensis
What are the virulence factor for Nocardia?
Superoxide dismutase and catalase
Nocobactin
A virulence factor of nocardia that provides resistance t oxidative killing by phagocytosis
Superoxide dismutase and catalase
What is Nocobactin?
Iron chelating compound (Iron Competing)
(Responsible for more severe type of infection)
What is the clinical infection of Nocardia?
Nocardiosis
What do you call a pulmonary infection for nocardia?
Confluent Bronchopneumonia
Causative agent of Confluent Bronchopneumonia
Nocardia asteroides
A type of pneumonia that causes granuloma, scar, and encapsulation of abscess
Confluent pneumonia
A severe type of pneumonia that causes damage in the tissues
Confluent bronchopneumonia
What is the difference of treatment for tuberculosis and confluent bronchopneumonia?
TB: 6 months
Confluent bronchopneumonia: within a year
What is the cutaneous infection for nocardia that causes major destruction of the tissue and bone or trauma of the skin
Actinomycotic mycetomas
Characterized by swelling, draining sinuses and granules
Mycetomas
Actinomycotic mycetomas pus characterized as?
pigmented and contains sulfur granules
Causative agent of Actinomycotic mycetomas?
Nocardia brasiliensis
Specimen for Actinomycotic mycetomas?
Scrape or Abscess aspirate (Pus)
What is the indicator for actinomycotic mycetomas?
Sulfur granules
What is the specimen for Confluent bronchopneumonia?
Sputum
In microscopic characteristics, is nocardia considered gram variable?
Yes
What are the factors of branching filamentous formation of actinomycetes?
Incubation period
Temperature time
Why incubation period is a factor for branching filamentous formation?
The longer the incubation, the higher the tendency of creating filamentous type of colony
Why temperature time is a factor for branching filamentous formation?
if supported with temp = longer and creates different forms of filaments
How many sulfuric acid contain in an partially acid fast bacilli?
0.5-1% Sulfuric acid
Acid alcohol is made up of?
Hydrochloric acid
What is the replacement of HCl decolorizing agent
0.5 - 1% sulfuric acid
Is Nocardia Beta hemolytic?
Yes
What is the Characteristics of Nocardia colony?
Chalky
Matte
Velvety / Dry
Crumbly
What is the temp of incubation for Nocardia and how many days?
22 or 37 for 3 - 6 days
What is he reason for difference in temp for Nocardia?
Mold or yeast form
What are the agars for Nocardia?
Buffered charcoal yeast extract agar
Thayer-Martin agar
Sabouraud’s agar
Mycosel agar
A media for fungal or fungi yeast or fungal morphology?
Sabouraud’s and Mycosel
Function of Thayer Martin agar for Nocardia?
Enhances growth (Sputum is supported in TMA)
