This document discusses the phylum Actinobacteria, focusing on the order Actinomycetales. Key points: - Actinomycetales includes large, diverse Gram-positive bacilli that form chains or filaments. They are found worldwide, especially in soil and aquatic environments, and play roles in decomposition, antibiotic production, and occasionally pathogenesis. - Genera discussed include Streptomyces, Nocardia, Rhodococcus, Corynebacterium, and Mycobacterium. Nocardia can cause opportunistic infections in immunocompromised individuals. - Characteristics include aerobic growth, branching filaments, and high G+C DNA content. Colonies of

1. ATINOMYCETES
PHYLUM: Actinobacteria
Sub class: Actinobacteridae
Order: Actinomycetales

2. ACTINOMYCETES
• Large, wide, diverse group of Gram positive bacilli
• Form chains or filaments
• World-wide distribution
• in soil esp. Streptomyces & aquatic environment
• Decompose organic matter aerobically;
mineralize it; Bio-degradation & Role in carbon
• Industrial Producers of anti-biotics eg
tetracyclines, macrolides, aminoglycosides
• Role as Pathogens

3. CHARACTERISTICS
• Most aerobes, few AnO2
• Gram positive
• High G & C content
• Grow on and below agar
• Cells remain together after division to form
elongated chains 1 um in width; may branch
• Extent varies: short chains. Filaments,coccobacil
• Form mycelia & asexual conidia
• Thin walled, asexual structures

4. GRAM SMEAR

5. SUB –ORDER
ACTINOMYCINEAE
• Straight or slightly curved rods
• AnO2 or Facultative An02
• Exist in oral/ nasal mucosa
• A israelli
• A bovis
• Cause infection, trauma, surgery of:
face, oral cavity, teeth, neck, thorax, abdomen

6. SUB 0RDER
CORYNEBACTERINEAE
• Corynebacterium
• Mycobacterium
• Nocardia/ Rhodococcus
SUB-ORDER
3 Genera
• STREPTPMYCINIAE
• Aerial hyphae; form spores

7. ACID-FAST CLASSIFICATION
1. TRUE ACID FAST:
Mycobacteria
2. WEAK ACID-FAST:
Nocardia
Rhodococcus
3. ACID-FAST NEGATIVE
Streptomyces
Actiomadura

11. MORPHOLOGY
• Aerobic
• Cell wall: shorter chained mycolic acids
• Growth Media: many ; Several days—weeks
• Colonies: Heaped, irregular, waxy
• Colour: white—orange---red
• Gram : positive
• Acid-fast: weak; more with 1-4% H2SO4
• Enzymes: catalase positive, urease positive
• Praffin: digested

16. Genus: NOCARDIA
• N nova
• N farcinica
• N asteroides
• N brasiliensis
• Form filaments; aerial hyphae, fragment to coccobacilli
• Cause different diseases
• Unique drug susceptibility: R to Ciprofloxacin
• Pathogens; non pathogenic
• World-wide in soil and water

17. PATHOLOGY
• Inhalation
• Pulmonary infection:
• Acute
• Chronic
• Dissemination: brain, skin
• Not transmitted between person to person
d/d: Streptomyces; they are non-pathogenic
• Rapid-growing Mycobacteria; mcroscop/macro

18. PATHOGENESIS
OPPORTUNISTIC INFECTION
Impaired cell –mediated immunity
• 1. corticosteroids
• 2. Organ transplant
• 3. AIDS
• 4. TB
• 5. ALCOHOLISM

19. CLINICAL FEATURES
• CHRONIC LOBAR PNEUMONIA
• Fever
• Weight loss
• Chest pain
• D/D: TB, other infections
• Pulmonary consolidation, abscess formation
• NO granuloma, caeseation,
• Spread: BRAIN, skin, kidney, eye

20. LAB DIAGNOSIS
• Sputum
• Pus
• CSF
• Biopsy
• Gram stain: positive bacilli, coccobacilli,
branching filaments
• AFB: modified stain
• Growth: most media
• Serology: not useful

22. Microscopy from culture

23. Streptomyces:CAESIN HYDROLYSIS

24. Caesin hydrolysis ; Nocardia negative

25. 12 Strepto; 3 N brasiliensis; 9 N
asteroides

26. PYRUVATE AGAR: white colonies

27. Sabourad’s agar

28. TREATMENT
• Trimethoprim-sulfamethoxsazole
• If no response
• Amikin
• Imepenem
• Minocycline
• Linezolid
• Cefotaxime
• Surgical drainage; resection
• Nocardia NOT inhibited by Ciprofloxacin

29. EMERGING ACTINOMYECETES
• OPPORTUNISTIC: IMMUNO-COMPROMISED
• GORDONIA
• Tsukamurella
• Stain: Modified acid-fast stain positive
• Gram: coryne-form; no branch
• Colonies: orange, wrinkled
• Non-sterile sources as sputa: disregard as
flora/contaminants

30. Tsuka-murella
• White- orange colonies
• Stain: long, straight or curved rods
IDENTIFICATION:
• Genera: cell wall fatty-acid analysis
• Gene sequencing: 16SrRNA

31. Infections:
• Post-op wound
• Blood-stream through catheter
• Ear
• Pulmonary
T/M:
• Gordonia: Vanco, carbepenems, linezolid
Aminoglycosides, fluoroquinolones
• Tsuka murella: SXT, fluoroquinolones,
clarithromycin, carbepenems

32. Madura medurae
• Morphology:
• Pale orange, pink or red, waxy, heaped and
folded. Dry, irregular and tough.
• Grows very slowly (may take more than 4
weeks to grow). Adhere to agar.
• First found in Madura, India. Produces
branching bacilli, non-acid-fast.

33. Madura medurae

34. d/d
ACTINOMYCOSIS
• Due to AnO2
• Gram positive

35. Causative bacteria
• N asteroids
• N brasiliensis: AFB
• Streptomysessomaliensis
• Actinomadura madurae
• IDENTIFY: biochemically
• chromatographically
Early T/m: various combinations
• Streptomycin, SXT, dapsone

36. STREPTOMYCES
• Sabourad’s
• White, chalky, dry,hard
• Adhere to medium; do not get off
• Sometime brittle, break easily
• Earthy smell

37. STREPTOMYCES