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A TB vaccine is available that is based on the so-called bacillus Calmette-Guérin (BCG) strain of M. bovis commonly found in cattle. In the United States, the BCG vaccine is only given to health-care workers and members of the military who are at risk of exposure to active cases of TB. It is used more broadly worldwide. Many individuals born in other countries have been vaccinated with BCG strain. BCG is used in many countries with a high prevalence of TB, to prevent childhood tuberculous meningitis and miliary disease.

The Mantoux tuberculin skin test ( [link] ) is regularly used in the United States to screen for potential TB exposure (see Hypersensitivities ). However, prior vaccinations with the BCG vaccine can cause false-positive results. Chest radiographs to detect Ghon complex formation are required, therefore, to confirm exposure.

a) a needle injects a small bubble into a person’s skin. B) a ruler is used to measure a red area on a person’s skin.
(a) The Mantoux skin test for tuberculosis involves injecting the subject with tuberculin protein derivative. The injection should initially produce a raised wheal. (b) The test should be read in 48–72 hours. A positive result is indicated by redness, swelling, or hardness; the size of the responding region is measured to determine the final result. (credit a, b: modification of work by Centers for Disease Control and Prevention)
  • What characteristic of Mycobacterium tuberculosis allows it to evade the immune response?
  • What happens to cause miliary tuberculosis?
  • Explain the limitations of the Mantoux tuberculin skin test.

Pertussis (whooping cough)

The causative agent of pertussis , commonly called whooping cough , is Bordetella pertussis , a gram-negative coccobacillus. The disease is characterized by mucus accumulation in the lungs that leads to a long period of severe coughing. Sometimes, following a bout of coughing, a sound resembling a “whoop” is produced as air is inhaled through the inflamed and restricted airway—hence the name whooping cough. Although adults can be infected, the symptoms of this disease are most pronounced in infants and children. Pertussis is highly communicable through droplet transmission, so the uncontrollable coughing produced is an efficient means of transmitting the disease in a susceptible population.

Following inhalation, B. pertussis specifically attaches to epithelial cells using an adhesin , filamentous hemagglutinin. The bacteria then grow at the site of infection and cause disease symptoms through the production of exotoxins. One of the main virulence factors of this organism is an A-B exotoxin called the pertussis toxin (PT) . When PT enters the host cells, it increases the cyclic adenosine monophosphate (cAMP) levels and disrupts cellular signaling. PT is known to enhance inflammatory responses involving histamine and serotonin. In addition to PT, B. pertussis produces a tracheal cytotoxin that damages ciliated epithelial cells and results in accumulation of mucus in the lungs. The mucus can support the colonization and growth of other microbes and, as a consequence, secondary infections are common. Together, the effects of these factors produce the cough that characterizes this infection.

Questions & Answers

I am about to enter school and am going for MCB
Olugbenga Reply
What is DNA damage and repair
Sree Reply
role of microorganism as pathogens
Parteek Reply
difference between endotoxin and exotoxin
Binkheir Reply
please I want the names of bacteria and the diseases they cause.
Ibrahim Reply
there are many we classify it according to their shapes gram negative or gram positive
so u may refer the book u guess or by when u want I can do a list for you and send u here
please do a list for me
I have the lost but it's too much to type ..
MSc entrance prepare books and questions LA etha base pani irukum..
Guhan Reply
kushal always prescott is the imp book to follow.search some objective mcqs books based on your syllabus
deepthi Reply
I want to clear entrance of ms university so I have no more idea so my preparation is based on my bachlor studies.
what are the opportunistic infection in aids stage
certain cancer or pneumonia 🤔
penicillium crysogenum
Kushal Reply
salam am also studying microbiology in university of Ilorin
Abubakar Reply
Salam am studying physiotherapy in bayaro university kano
Walaikum salam
Hw u
HRU frinds
any good reference for oncology?!!!!
Pankaj Reply
K.D tripathi
what is the microbiology
Fadumo Reply
it is the study of microorganisms
microorganis means
the organism can not be seen by eyes they can be seen with the help of microscope
microbiology is the study of microorganism and microorganism are such as bacteria ,parasite, viruses and fungi and etc.. those are cant be seen with asked eyes and can be seen with help of microscope . I hope this helps you
what is virology
Bismarck Reply
the study of viruses
what is myrology
myrology or mycology?
the study of fungi.
Mycology study fungi
what are the major topics that you cover under micro biology
Bismarck Reply
How do u apply micro biology in medicine
Bismarck Reply
in preventing, diagnosis and treatment of infectious diseases.
and also in carrying out test And Analysis
what is micro biology
Bismarck Reply
study of microorganisms
OK thanks alot

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Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
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