Download Fungi-like Bacteria

Actinobacteria
(Actinomycetes)
Aerobic gram-positive bacteria
Nocardia, Rhodococcus, Actinomadular,
treptomyces, …
Anaerobic gram-positive bacteria
Actinomyces, Peptostreptococcus, Propionibacterium,
Lactobacillus,…
Actinomycetes
Filamentous, Branching Bacilli
Nonmotile
May produce mycelium
Gram + and may be acid-fast
living normally in oral cavity, tonsils and intestines
and also in soil.
Some aerobic and some anaerobic
Actinomyces and Nocardia primary genera involved
in Actinomycosis
Actinomyces
Actinomycosis (Lumpy jaw)
Non-spore forming (mostly) anaerobic grampositive bacteria
Colonize the upper respiratory tract, oral cavity
The most common cause is A. israelii, a normal
flora
Modified acid fast (1% instead of 20% H2SO4) :
Negative
Actinomycosis
An Endogenous infection & Painful bscesses in
Cervicofacial
• Common complication of tooth extraction,
poor oral hygiene and rampant dental caries.
• Oral Actinomyces play significant role in
development of plaque and dental caries.
Thoracic
Abdominal
The outbreak is unrelated to age, sex, season,
or occupation.
Actinomycosis (cont.)
Starts with a trauma moving bacteria inside the
mucosa.
Actinomycosis characterized by:
- abscesses grow larger as the disease progresses,
often over months.
- A chronic granolomatous disease.
- Purulent
Pathogenesis
Abscess and lesions with fibrous walls and pus with
sulfur granules develop.
Granules include: macrophages, other histologic
cells, fibrin and bacteria. The edges of bacteria have
come out of these granules.
Symptoms and signs of Actinomycosis
Laboratory Diagnosis
Prompt transport of specimens to laboratory in
anaerobic device
Direct examination
“Sulfur granule”
(10x) Exudate from
an abdominal wound
infection
Lab diagnosis:
by Exudates, Pus and drainage samples
Microscopic
 Examined for granules (1 mm), yellow color
 Crushed between two slides.
Culture
 Washed several time in sterile distilled water
 Crushed with sterile glass rod, and inoculated onto media.
Laboratory Diagnosis
Direct examination
The delicate
filamentous bacilli
(arrow) at the peripheral
of crushed granule
Laboratory Diagnosis
Culture
BHI, BA, Thioglycolate broth
Aerobic condition
Anaerobic condition
370C
370C
Molar tooth
colony
NOCARDIA
Aerobic
Saprophytes in soil, water
Branching filament
Fragmentation
Gram-positive
rod, coccoid form
beaded form
Nocardia asteroides
Nocardia brasiliensis
GPB, Catalase +, urease +, parafine hydrolysis
Colonies: grow in about 1 week, irregular,
outstanding, different pigments (white, orange, red).
NOCARDIA
Cell wall; mycolic acid (wax-like cell wall)
Modified acid fast (1% instead of 20% H2SO4)
Acid fast
Nocardia causes mostly opportunistic infections (in
AIDS, Tuberculosis….)
Transmission
Normally found in soil, these organisms cause
occasional sporadic disease in humans and animals.
Noccardia is an oral microflora. Also in the normal
gingiva and periodontal pockets along with other
species, such as Actinomyces.
Nocardia brasiliensis causes lobar pneumonia
(pulmonary disease similar to TB).
Fever
abscess
chest pain
different from TB by lack of granoluma.
Nocardiosis
It is most common in men with a compromised
immune system.
In patients with brain infection, mortality exceeds
80%.
In other forms, mortality is 50%, even with
appropriate therapy.
Treatment
Penicillin for 6-12 months
Nocardiosis
Laboratory Diagnosis
Direct examination
Sputum, pus, tissue biopsy
Gram’stain
GPB, branching
Modified acid fast : positive
Laboratory Diagnosis
Culture
BHI, SDA, BA, Thayer-martin agar
- Glabrous, folded, heaped Nocardia brasiliensis,
SDA, 300C, 9 days
- White to pink, orange
Laboratory Diagnosis
Identification
Biochemical test: 1. Resistant to Lysozyme
2. Paraffin hydrolysis
Lysozyme test
Right : resistant to
lysozyme
Left : not grow in
the presence of
lysozyme
Laboratory Diagnosis
Isolation
Paraffin baiting technique
Glass rod coat with paraffin
McClung’s carbon free broth
Incubate 370C, 2 weeks
Streptomyces
Antibiotic production