Mycobacterium (1)

Mycobacterium

Dr. J Sheehama

UNAM School of Medicine

Tuberculosis is a

leading cause of death

worldwide (~1.4

million)*

Namibia

Population: 2.1 million

In 2009: TB case

notification rate of 634

per 100 000**

In 2010: TB case

notification rate of 589

per 100 000

*WHO

** MoHSS

Introduction and background

• Pulmonary TB is caused by Mycobacterium tuberculosis

– Lung is the prime target for infections

• TB is one of the opportunistic infections in HIV-AIDS patients

Introduction and background information

Introduction and background

• Transmission of TB

Mycobacterium tuberculosis

Mycobacterium leprae (uncommon)

Mycobacterium avium-intracellulaire Complex

(MAC) or (M. avium)

Important Human Pathogens

Lipid-Rich Cell Wall of Mycobacterium Mycolic acids

CMN Group: Unusual cell wall

lipids (mycolic

acids,etc.)

(Purified Protein Derivative)

Acid-Fast (Kinyoun) Stain of

Mycobacterium

NOTE: cord growth (serpentine

arrangement) of virulent strains

Photochromogenic Mycobacterium

kansasii on Middlebrook Agar

NOTE: Mycobacteria pathogenic

for humans can be differentiated

(Runyon Groups) by:

speed of growth (all are

slower than most other

pathogens) and by

production of chromogenic

pigments (in light, in dark,

or none)

Improved Mycobacterial Isolation Medium

Eight Week Growth of

Mycobacterium tuberculosis on

Lowenstein-Jensen Agar

Pathogenic Mycobacterium spp.

BCG

AIDS

patients

Mycobacterial Clinical Syndromes

Diagram

of a

Granuloma

NOTE: ultimately a

fibrin layer develops

around granuloma

(fibrosis), further

“walling off” the

lesion.

Typical progression

in pulmonary TB

involves caseation,

calcification and

cavity formation.

Laboratory Diagnosis of

Mycobacterial Disease

Nucleic acid probes

Nucleic acid sequencing

Differential Characteristics of

Commonly Isolated

Mycobacterium spp.

Mycobacterium

tuberculosis

Mycobacterium

tuberculosis

Infections

Incidence of Tuberculosis in USA

Mycobacterium

tuberculosis

Infections (cont.)

BCG (bacille Calmette-Guerin)

= attenuated M. bovis

Positive PPD + Chest X-Ray +

MDR-TB a serious

global health threat

Pneumonia

Granuloma formation with fibrosis

Caseous necrosis • Tissue becomes dry & amorphous (resembling cheese)

• Mixture of protein & fat (assimilated very slowly)

Calcification • Ca++ salts deposited

Cavity formation • Center liquefies & empties into bronchi

Typical Progression of

Pulmonary Tuberculosis

PPD Tuberculosis Skin Test Criteria

PPD = Purified Protein Derivative from M. tuberculosis

Chest X-Ray of Patient with Active


Mycobacterium Tuberculosis

Stained with Fluorescent Dye

Mycobacterium leprae

Mycobacterium leprae Infections

Mycobacterium leprae Infections (cont.)

Tuberculoid vs. Lepromatous Leprosy Clinical Manifestations and Immunogenicity

Lepromatous vs. Tuberculoid Leprosy

Lepromatous Leprosy (Early/Late Stages)

Lepromatous Leprosy Pre-

and Post-Treatment

Clinical Progression of Leprosy

Effect of Cell-Mediated Immunity on

Leprosy Clinical Outcome

Mycobacterium avium-

intracellulaire Complex

(MAC)

Mycobacterium avium-intracellulaire Infections


M. avium-

intracellulaire

Complex (MAC)

Progression vs.

CD4 Count in

AIDS Patients

Mycobacterium avium-intracellulaire in

Tissue Specimens

Low Magnification High Magnification

REVIEW of

Mycobacterium

Mycobacterium tuberculosis

Mycobacterium leprae (uncommon)

Mycobacterium avium-intracellulaire Complex

(MAC) or (M. avium)

Important Human Pathogens

REVIEW

Lipid-Rich Cell Wall of Mycobacterium Mycolic acids

CMN Group: Unusual cell wall

lipids (mycolic

acids,etc.)

(Purified Protein Derivative)

REVIEW

Pathogenic Mycobacterium spp.

BCG

AIDS

patients

REVIEW

Mycobacterial Clinical Syndromes

REVIEW

Diagram

of a

Granuloma

NOTE: ultimately a

fibrin layer develops

around granuloma

(fibrosis), further

“walling off” the

lesion.

Typical progression

in pulmonary TB

involves caseation,

calcification and

cavity formation. REVIEW

Review of Mycobacterium

tuberculosis

Mycobacterium

tuberculosis

Infections

REVIEW

Mycobacterium

tuberculosis

Infections (cont.)

BCG (bacille Calmette-Guerin)

= attenuated M. bovis

Positive PPD + Chest X-Ray +

MDR-TB a serious

global health threat

REVIEW

Pneumonia

Granuloma formation with fibrosis

Caseous necrosis • Tissue becomes dry & amorphous (resembling cheese)

• Mixture of protein & fat (assimilated very slowly)

Calcification • Ca++ salts deposited

Cavity formation • Center liquefies & empties into bronchi

Typical Progression of


REVIEW

Review of Mycobacterium leprae

Mycobacterium leprae Infections

REVIEW

Mycobacterium leprae Infections (cont.)

REVIEW

Lepromatous vs. Tuberculoid Leprosy

REVIEW

Lepromatous Leprosy (Early/Late Stages)

REVIEW

Clinical Progression of Leprosy

REVIEW

Effect of Cell-Mediated Immunity on

Leprosy Clinical Outcome

REVIEW

Review of Mycobacterium avium-

intracellulaire Complex

(M. avium)


REVIEW


REVIEW

M. avium-

intracellulaire

Complex (MAC)

Progression vs.

CD4 Count in

AIDS Patients

REVIEW

Home work – Due

25/02/2015

– describe the risk factors

of TB infection in your

Region

Health & Medicine

Mycobacterium (1)