This document provides information on mycoplasma and actinomycetes. It discusses that mycoplasma are the smallest free-living microbes that lack cell walls and can cause respiratory infections like atypical pneumonia. Actinomyces are soil bacteria that can cause cervicofacial actinomycosis in humans through dental infections. Nocardia are acid-fast soil bacteria that can cause pulmonary or disseminated nocardiosis through inhalation or skin inoculation. Laboratory diagnosis involves culture, staining, biochemical testing and PCR for mycoplasma and actinomycetes. Treatment involves macrolides or other antibiotics.

1. MYCOPLASMA

2. 1) Introduction
• Smallest microbes
• Resemble to virus (Size: 150-130 nm , FILTERED BY bacteria filter)
• D/F from virus as
• A) free living in environment
• B)Grow on artificial culture media

3. • C) lack rigid cell wall (sterole)
• D) completely resistance to antibiotic
• E) highly pleomorphic (gpc , gnb or filamentous)
• F) Poorly gnb better stained with giemsa stained
• G) Multiply (binary fission)
• H) Non sporing , non flagellated (gliding motility -

6. i) HISTORY
• Nocard and Roux: from bovine
pleuropneumonia
• Myco-fungus , plasma-plasticity of shape
• Monroe eaton : pathogenic
(mycoplasma pneumoniae)

7. ii) CLASSIFICATION
• Class: mollicutes (mollis-soft and cutis-skin)
• Order: mycoplasmatales (5 families)
• Only mycoplasmataceae (mycoplasma and
ureaplasma: human pathogen
• M.homonis , M.genitalium , U. Urealyticum
and U.parvum

8. 2) MYCOPLASMA PNEUMONIA
• M.Pneumonia : primary atypical pneumonia
• A) antigen :
• i) glycolipid antigen: nonspecific in diverse
tissue
• B) membrane bound protein : attachment to
host cell surface

9. i) PATHOGENESIS
• A) Adhesion : respiratory mucosa by membrane bound
adhesion protein
• B) induce injury to host respiratory tissue : by
• i) hydrogen peroxide
• C) cytotoxin : ADP ribosylation and vacuolating
• D) Lipoproteins : induce inflammation

11. ii) EPIDERMIOLOGY
• Worldwide
• Transmission : respiratory droplets
• i/c: 2-4 weeks

12. iii)CLINICAL MANIFESTATION
• A) UPPER RESPIRATORY TRACT
INFECTIONS (URTI): pharyngitis ,
tracheobronchitis or otitis media (rarely).
• B)Pneumonia : Atypical community
acquired interstitial pneumonia
(chlamydophila pneumoniae , legionella
pneumophila and viral pneumonia)

13. • 3-13% of infected person
• Wheeze , dry cough and pribronchial pneumonia with
thickened bronchial marking and streaks of interstitial
infiltration on chest X-ray

16. • C) EXTRAPULMONARY
MANIFESTATION: RARE (occur either
active mycoplasma or postinfectious
autoimmune phenomenon)
• i) Neurologic manifestation:
meningoencephalitis , encephalitis ,
guillain-barre syndrome and aseptic
meningitis

17. • Ii) dermatologic: skin rashes
• Iii) cardiac: myocarditis ,
pericarditis
• Iv) rheumatologic: reactive
arthritis
• V)Haematologic: Anemia and
hypercoagulopathy

18. iv)LABORATORY DIAGNOSIS
• a) SPECIMEN COLLECTION AND TRASPORT: throat swab
and nasopharyngeal aspirate , bronchial brushing , bronchoalveolar lavage
and lung biopsy.
• MUST TRANSPORT :
• A) STANDARD MYCOPLASMA FLUID MEDIUM: fetal bovine serum ,
gelatine and penicillin.
• B)VIRAL TRANSPORT MEDIUM: ampicillin and cefotaxime
• IF DELAY : 40C

19. • b) Culture:
• A) standard solid medium: horse serum and penicillin
• B) Standard liquid medium: glucose and penicillin and
phenol red
• C) diphasic medium: solid and liquid media
• D)Sp-4 medium: more complex and fetal bovine serum
• E) Hayflick modified medium : heart infusion broth
• SPECIMEN INOCUBATED AT 370 C FOR 5-7 DAYS

20. • growth as:
• In liquid medium: turbidity and
colour change (red to yellow) of phenol
red indicator due to fermentation of
glucose.

21. • In solid medium : colony appear as
• Central opaque granular area surrounded by flat,
translucent peripheral growth (fried egg
appearance)
• Size: 200-500 micro met (mycoplasma)
• 15-60 micro met (ureaplasmas)

22. • Colonies can be examined by:
• i) hand lens
• Ii) dienes staining: plate flooded in alcoholic solution of
methylene blue and examined under low power microscope.
• Mycoplasma retain colour for 2 days
• Ureaplasma : reddish to greenish-blue

23. c)IDENTIFICATION
• Most mycoplasma: hemolytic colonies
• Hemadsorption test: m.pneumoniae agglutinates guinea
pig red blood cells
• Tetrazolium reduction test : reduce colourless
tetrazolium compound to red coloured formazan
• Growth inhibition test : M.pneumoniae inhibit by adding specific
antisera

24. d)Antigen detection
• Direct immunofluorescence test
• Capture ELISA assay using monoclonal
antibodies

25. e)ANTIBODY DETECTION IN SERUM
• A) Specific Antibody Detection Tests: Antibodies to
m.pneumoniae protein and glycolipid antigen detected after 1 week of illness
and peak 3-6 week.
• IgM elevated in children
• IgG DETECTED IN ACUTE PHASE
• I) SPECIFIC ANTIBODY DETECTION TEST
• CFT: antibody to glycolipid antigen. Not use now
• Immunofluorescence assay
• Latex agglutination assay
• ELISA using protein P1 antigens

26. • II) Nonspecific Antibody Detection tests:
heterophile antigens (glycolypid haptenes) crooss react with i
antigen of rbc or carbohydrate antigen of F Streptococcus cell
wall.
• Cold agglutination test : test done with Human O Group
antigen at 4o c
• Streptococcus MG TEST: less use now a day

27. • Molecuar methods: Multiplex PCR detects 16s Rrna
and PI adhesion gene
• Real time PCR: Useful for quantitative detection of
M.pneumoniae

28. e)TREATMENT
• MACROLIDES (AZIHROMYCIN , 500 mg on a
day , then 250 mg on 2-5 days)
• Alternative drugs:
• Doxycycline
• Fluoroquinolones(levofloxacin , moxifloxacin
and gemifloxacin not ciprofloxacin)

29. 3)UROGENITAL MYCOPLASMAS
• M.homonis , M.genitalium , ureaplasma :
urogenital tract disease
• Colonize female lower urogenital tract
• Transmission: sexual contact or mother to fetus during
birth

30. a)CLINICAL MANIFESTATION
• Non-gonococcal urethritis and epididymitis
(ureaplasma and M.genitalium)
• Pyelonephritis (M.hominis) and urinary calculi
(ureaplasma)
• Pelvic inflammatory disease: (M.hominis)
• M.hominis: brain abscess , wound infection

31. b)Laboratory Diagnosis
• Culture and pcr

32. ACTINOMYCETES

33. 1)INTRODUCTION
• GPB
• Non motile
• Non sporing
• Non capsulated
• Branching (fungi)
• Soil saprophytes

34. 2)Genera:
• i)Actinomyces: aerobe , non-acid fast
• Ii)Nocardia: aerobe , acid fast(actinomycetoma and
pulmonary infection)
• Iii) Actinomadura: aerobe , acid fast (actinomycetoma).
• Iv) Streptomyces: aerobe , acid fast(actinomycetoma) ,
source of antibiotoc (streptomycin)
• V) Micropolyspora and thermoactinomyces:
hypersensitivity pneumonitis

35. i)ACTINOMYCES
• Soil saprophytes
• Oral commensial
• A.israelii: most common infecting man
• A.naeslundii and A.odontolyticus: rare

36. a)PATHOGENESIS
• Actinomycosis: chronic
suppurative and granulomatous
infection
• Multiple abscesses with sinuses ,
discharge (granules), on later stage :
fibrosis and tissue destruction
• Actinomyces (rays like appearance)

37. • Mode of infection:
endogenous and trauma
(dental extraction)
• Painless indurate swelling
with sinuses , pus
(granules)

38. i)CLINICAL MANIFESTATIONS
(ACTINOMYCOSIS)
• Cervicofacial actinomycosis: Most
common form , painless , slow-growing , hard
mass with cutaneous fistulas (lumpy jaw)

39. • Other form (rare)
• Abdominal form:
spillage to intestinal
flora secondary to
surgery
• Pelvic form :
intrauterine
contraception devices
insertion

40. • Disseminated form : haematogenous
spread
• Dental caries : A.naeslundii and
A.odontolyticus
• Brain abscess
• Bone destruction

41. ii)LABORATORY DIAGNOSIS
• A)SPECIMEN: discharge from sinuses ,
bronchoalveolar lavarge ,sputum or tissue
section
• B) Direct microscopy :
• Pus wash in saline
• Sediment collect(white granules : sulfur
granules)
• Crushed between 2 slides
• Gram stain

42. • C) culture : anaerobically at
37oc
• Thyoglycollate :A.israelli –
fluffy ball , A.bovis-uniform
turbidity
• Brain heart infusion agar :

43. • Molecular methods : PCR-RFLP
• TREATMENT :

44. ii)NOCARDIA
• Edmond nocard 1898
• Gpb filamentus
• d/f actinomyces by acid fast nature
• 50 species (N.asteroides-star shaped ,
N.brasiliensis)
• Soil saprophytes

46. a)Pathology and pathogenesis
• Worldwide
• Adult male
• Acquire of infection Soil by
• A) inhalation of bacterial fragment :pulmonary
necrosis (N.brasiliensis , N.farcinica and
N.pseudobrasiliensis)
• B) Transcutaneous inoculation :Cutaneous and
subcutaneus (mycetoma)

47. • N.brasiliensis , N.asteroides
• No person to person transmission
• Nocardiosis : abscess with neutrophil
infiltration surrounded by granulation tissue

48. • Risk factor: AIDS , corticosteroides , organ
transplant and tuberculosis
•
• clinical manifestations
• A) pulmonary nocardiosis : most common
form , cough with thick sputum.
• pericarditis , laryngitis , trachetitis and
bronchitis

49. • B) extrapulmonary nocardiosis :
dissemination via blood
• Subacute abscess
• Most common site: brain , skin , kidney ,bone
and muscle
• Brain infection (supratentorial)
• Meninigitis : uncommon

50. • C) Actinomycetoma: chronic granulomatous
(subcutaneous tissue) of feet and hand.
• Subcutaneous nodular swelling
• Multiple sinus
• Discharge containing granules
• Bony deformities

51. b)Laboratory diagnosis
• 1)Specimens: sputum, pus and granules
• 2) Direct microscopy:
• i) gram staining: gram positive branching and
filamentous bacilli.
• Sputum : numerous lymphocytes and
macrophages and branching bacilli

52. • Ii)Modified acid fast staining : 1% sulphuric
acid (kinyon method)
• Branching and filamentous red colour bacilli

53. • 3) culture:
• obligate aerobe
• BHI
• SDA
• AT 37O C for 2 days to 2 weeks
• Cremy , wrinkled , orange or pink pigment
(carotenoid like pigment)
• Some colony :wool ball appearance

54. • Selective media:
• buffer yeast extract agar (vancomycin ,
polymyxin)
• SDA (chloramphenicol)
• Paraffin bait techniques: carbon source
• LJ medium

55. • 4)Biochemical:
• Catalase positive
• Non motile
• Decomposition of casein and tyrosine
• Growth in lysozymes
• Acetamide utilization
• Growth at 45oc for 3 days
• Acid from rhamnose

56. 5)Treatment :
• sulphonmide or cotrimoxazole (all form of
nocardiosis)
• Brain abscess or pneumonia: cotrimoxazole
• Duration of treatment:
• For severe disease:(6-12 month – intact immune ,
1 year for immune deficient)
• Lymadenitis and skin abscess:2month
• Actinomycetoma :6-12 month after cure
• Keratitis: 2 month

57. • ACINOMASURA : SELF STUDY