Download Tuberculosis

Stavros Giannoukos
Ben Altland
Kingdom: Bacteria
Phylum: Actinobacteria
Order: Actinobacteridae
Family: Actinomycetales
Genus: Mycobacterium
Species: tuberculosis
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Aerobic
Rod shaped
Non-motile
Neither Gram-negative nor
Gram-positive.
Stains weakly Gram-positive.
Genome was mapped in its
entirety in 1998.
The main cause of
Tuberculosis, however other
species of mycobacterium can
also cause the disease.
Highly pathogenic
Long generation time (15-20
hours) prevents recognition of
the immune system.
Low permeability membrane
allows survival inside
macrophages.
Only susceptible to a select few
antibiotics.
Over 20% are resistant to
primary treatment. And 2% are
resistant to secondary treatment.
Byproducts of the infection
inhibit oxygen transfer from
Causes extreme necrosis of
Lung tissue, leading to
emphysema and eventual death
by asphyxiation.
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M.TB. is found exclusively in the human body.
Complexes primarily form in the lungs.
If infection is not contained by granuloma
formation, infection can spread to other tissues
of the body.
No other reservoirs for the bacteria exist in the
world.
Believed to have been created from the
mutation of Mycobacterium leprosy within the
human body.
Lungs (Pulmonary alveoli)
Ghon focus
Central Nervous System
Circulatory System
Lymphatic System
Joints
Skin
Cross sections of an alveoli
infected with M.TB. The blue
spheres are granulomas, the
immune response to contain the
infection.
Photo of the
rare event
of an M.TB
infection of
the skin.
Only 10% of infected patients
are symptomatic.
Active symptoms include chest
pain, coughing up blood, or
white mucosa and necrotic
tissue, and a productive,
persistent cough for more than
three weeks.
Systemic symptoms of wide
spread infection are, weight loss,
loss of apatite, fever, chills, night
sweats, paling (loss of skin
color) and rapid fatigue.
Comprehensive review of medical
history.
Chest X-ray
Physical exam
Skin test of an active TB skin
infection site.
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Complete treatment takes 6-9
months.
Multiple drugs are used in
combination.
Isoniazid– Inhibits cells wall
synthesis.
Ethambutol- Inhibits cell wall
synthesis.
Pyrazinaide- Destroys plasma
membrane and inhibits metabolic
processes. Exact mechanism
unknown.
Rifampin- Inhibits RNA
synthesis.
A child receiving a
tuberculosis vaccine at
school in Bulacan province,
Philippines, c. 1952.
UNICEF/ICEF-2539
Prevention almost entirely consists of avoiding
contact with great numbers of people potentially
infected with M.TB.
M.TB is spread by the transmission of sneeze
droplets from person to person, with only one
droplet between .5 and 5 micro liters required to
transmit an infections amount of bacteria.
40,000 of these drops are released with every
sneeze.
Infected persons are usually required to wear
masks to prevent transmission through sneezing.
The vaccine BCG exists derived from attenuated
M. bovine virus, but is not approved for use in the
US.
World TB incidence. Cases per 100,000;
Red > 300, orange = 200–300; yellow = 100–
200; green 50–100 and grey <50. Data from
WHO, 2006.
Is the most prevalent pathogen
infection in the world, with an
estimated 2,000,000,000 of the
worlds population infected on
some level.
Also referred to as the “White
plague.”
Highest concentrations of
infections occur in areas with
higher HIV prevalence. (South
Africa has 718/100,000
population infected.)
India has the single largest
number of infections with over
1,800,000 cases.
Occurs less frequently
(between 5<50/100,000
population) in more developed
countries.
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Over 8,000,000 people become infected with
tuberculosis annually.
2,000,000 people die annually from tuberculosis.
In 2004, worldwide there were 14.6 million people
with active TB disease, with 9 million new cases
being presented that year.
The world’s greatest infectious killer of women of
reproductive age, and the leading cause of death
among people with HIV.
In 2006, there was a total of 13,767 deaths in the
U.S. from TB (4.6/100,000 population) reported.
This is a 3.2% decrease from 2005, and the lowest in
U.S. history since tracking began in 1953.
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www.CDC.gov
http://library.med.utah.edu
http://www.textbookofbacteriology.net
http://www.microbiologybytes.com
National Institute of Allergy and Infectious Diseases (NIAID). Microbes in Sickness
and in Health. 26 October 2005. Retrieved on 3 October 2006.
(1997) "Diagnosis and treatment of disease caused by nontuberculous mycobacterium.
This official statement of the American Thoracic Society was approved by the Board of
Directors, March 1997. Medical Section of the American Lung Association". Am J Respir
Crit Care Med 156 (2 Pt 2): S1–25. PMID 9279284.
Nahid P, Pai M, Hopewell P (2006). "Advances in the diagnosis and treatment of
tuberculosis". Proc Am Thorac Soc 3 (1): 103-10. PMID 16493157.