Tuberculosis disease

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Mycobacterium tuberculosis under microscope [1]

Etiology/Bacteriology

Taxonomy

Mycobacterium tuberculosis Stain [2]

Kingdom: Bacteria
Phylum: Actinobacteria
Class: Actinobacteria
Order: Actinomycetales
Family: Mycobacteriaceae
Genus: Mycobacterium
Species: tuberculosis

Description

Mycobacterium tuberculosis Stain [3]

Mycobacterium tuberculosis is an acid fast, nonmotile, obligate anaerobe. These bacilli range in size from 2-4 µm and have an incredibly slow generation time of 15 to 20 hours. The genus of Mycobacterium is defined by the mycolic acids and waxes, which makes the bacterium resistant to many bactericidal agents. For this reason, the tuberculosis disease can be easily spread due to the difficulty in killing the bacteria. Mycobacterium tuberculosis is very diverse and provides different geographic areas with different disease symptoms.

Clinical Features and Symptoms

Mycobacterium tuberculosis presented via X Ray [4]

There are multiple forms of tuberculosis which is separated into two categories; pulmonary and extrapulmonary tuberculosis. It is important to note due to its slow development, TB symptoms can take months to years to begin. If the tuberculosis bacteria invades the body without causing symptoms it is considered latent, whereas active TB causes symptoms to arise.

Pulmonary TB symptoms include:

• More than three weeks of chronic coughing in which phlegm is present. It is not abnormal for blood to be present in the phlegm
• Shortness of breath, which will continue to worsen as the disease worsens
• Weight loss due to a loss of appetite
• Excessive sweating while sleeping
• Intense lack of energy
• Body aches and pains that have occurred for greater than three weeks

Extrapulmonary TB diseases and symptoms include:

Lymph Node Tuberculosis

• Painless lymph node swelling; any nodes in the body can be affected, but the most common place is the neck
• The constant swelling of the lymph nodes causes the fluid to eventually leak through the barrier of the skin

Skeletal Tuberculosis (Pott’s Disease)

• Painful bones
• The infected bone will begin to weaken and become curved
• Absence of feeling and movement in the diseased bone
• Due to the bone being weakened, it has a high risk of being fractured

Gastrointestinal Tuberculosis

• Diarrhea
• Bleeding from the rectum
• Pain in the abdominal region

Gestrointestional Tuberculosis

• Urethral burning while urinating
• Presence of blood in urine
• Persistent need to urinate
• Aches and pain in the groin

Central Nervous System Tuberculosis

• Presence of headaches
• Brain swelling
• Neck stiffness
• Illness
• Decrease in vision
• Deterioration in mental awareness
• Onset of seizures

Host Immune Response

Immune Response to Mycobacterium tuberculosis [5]

References

1 Conway, Tyrrell. “Genus conway”. “Microbe Wiki” 2013. Volume 1. p. 1-2.