Tetanus, Tuberculosis, H1N1

1. Pathogenic Microorganisms
Tetanus
Tuberculosis
H1N1
Dr. Aswartha Harinatha Reddy
Assistant Professor
Department of Biotechnology
Bangalore

2. Epidemic:
 An epidemic is the rapid spread of infectious disease to a large
number of people within a short period of time, usually two weeks
or less.
 Epidemics of infectious disease are generally caused by several
factors.
 Such as genetic change in the pathogen reservoir.
 Increased virulence and Changes in the resistant of host.
 Example: Influenza infections.

3.  An epidemic may be restricted to one location; however, if it
spreads to other countries or continents and affects number
of people, it may be termed a pandemic.
 Example: Influenza infections.

4. Endemic:
 An endemic disease is always present in a certain population or
region.
 The constant presence of diseases or infectious agents within a
given geographic area or population group.
 Malaria is best examples.
 Hepatitis B (HBV), Yellow fever and Syphilis is also endemic
throughout the world.

5. Pandemic:
 A pandemic is an epidemic of infectious disease that has
spread through human populations across a large region; for
instance multiple continents, or even worldwide.
 Examples: Influenza, Zika virus, Smallpox, Tuberculosis,
and HIV.

6. Tetanus
 Tetanus caused by Clostridium tetani.
 Gram-positive, rod-shaped bacteria.
 Spore-forming (Terminal endospore),
anaerobic.
 Found in soil, especially in the intestinal
tracts and feces of various animals.
 Strictly fermentative mode of metabolism.
 Hippocrates first described the disease.

7.  Not pathogenic to humans and animals by invasive infection but
by the production of a potent protein toxin.
 Tetanus toxin or tetanospasmin.
 The toxin has a specific affinity for nervous tissue, it is
referred to as a neurotoxin.
 The toxin has no known useful function to C. tetani.
Pathogenicity:

8.  The tetanus toxin protein has a molecular weight of 150kDa.
 It is translated from the tetX gene as one protein which is
subsequently cleaved into two parts: a 100kDa heavy or
Beta-chain and a 50kDa light or Alpha-chain.
 The chains are connected by a disulfide bond.

9.  Initially binds to peripheral nerve terminals.
 Transported within the axon and across synaptic junctions until it
reaches the central nervous system.
 Blocks the release of inhibitory neurotransmitters (glycine and
gamma-amino butyric acid) across the synaptic cleft, which is
required to check the nervous impulse.
 If nervous impulses cannot be checked by normal inhibitory
mechanisms, it leads to muscular contraction and spasms
that are characteristic of tetanus.

11. Methods of transmission
 C. tetani can live for years as spores in animal feces and soil.
 As soon as it enters the human body through a major or minor
wound and the conditions are anaerobic, the spores germinate
and release the toxins.
 Only the growing bacteria can produce the toxin.
 C. tetani infectious not contagious from person to person.

12. Symptoms
 Painful, powerful muscle contraction
 Stiffness of jaw (also called lockjaw)
 Stiffness of abdominal and back muscles
 Contraction of facial muscles
 Fast pulse
 Fever
 Sweating

13. Methods of diagnosis
Tests that may be performed include the following:
 Culturing of the wound site.
 Tetanus antibody test.

15. Clinical treatment:
 The bacteria are killed with antibiotics, such as penicillin or
tetracycline; further toxin production is thus prevented.
 The toxin is neutralized with shots of tetanus immune globulin,
TIG.

16. Method of prevention - immunization
 The tetanus toxoid is a formalin-inactivated toxin, with an
efficiency of approx. 100%.
 The DTP vaccine includes tetanus, diphteria and pertussis
toxoids; it is routinely given in the US during childhood.
 The antitoxin levels decrease over time, booster immunization
shots are needed every 10 years.

17. Tuberculosis

18. Morphology of Bacteria:
 Mycobacterium tuberculosis is the causative
agent of tuberculosis.
 First discovered in 1882 by Robert Koch.
 Cells are curved rod-shaped and are often
seen wrapped together, due to the presence
of fatty acids in the cell wall.
 M. tuberculosis cell wall made up of
mycolic acids.

19.  Acid-fast staining (Ziehl-Neelsen) used to identify M.
tuberculosis. with a microscope.
 The physiology of M. tuberculosis is highly aerobic and
requires high levels of oxygen.
 Primarily a pathogen of the mammalian respiratory
system, it infects the lungs.

20. Transmission:
 When people with active pulmonary TB cough, sneeze, speak,
they expel infectious aerosol droplets 0.5 to 5.0 µm in
diameter.
 People with prolonged or close contact with people with TB
are at particularly high risk of becoming infected, with an
estimated 22% infection rate.

21. Pathogenesis:
 About 90% of infected people with M. tuberculosis have
asymptomatic.
 The people with HIV is the high risk of developing active TB.
 TB infection begins when the mycobacteria reach the
pulmonary alveoli of the lungs.
 Macrophages identify the bacterium in the alveoli and
eliminate it by phagocytosis.

22.  During this process, the bacterium is enveloped by the
macrophage called a phagosome.
 The phagosome then combines with a lysosome to create a
phagolysosome.
 In the phagolysosome, the cell attempts to use reactive oxygen
species and acids to kill the bacterium.
 However, M. tuberculosis has a thick, waxy mycolic acid capsule
that protects it from these toxic substances.
 M. tuberculosis replicate inside the macrophage.

23.  The primary site of infection in the lungs, known as the "Ghon
focus", is generally located at the lower part of the upper lobe.
 The hematogenous transmission can also spread infection to
more distant sites, such as peripheral lymph nodes, the
kidneys, the brain, and the bones.
 Healthy Macrophages, T lymphocytes, B lymphocytes, and
fibroblasts aggregate around the infected macrophage to form
granulomas or inflammation result cavities are formed in
lungs.

25. Symptoms:
 There are two types of TB conditions: latent TB infection and TB
disease.
 TB bacteria can live in the body without making you sick. This is
called latent TB infection.
 In most people who breathe in TB bacteria and become infected,
the body is able to fight the bacteria to stop them from growing.
 People with latent TB infection do not feel sick, do not have any
symptoms, and cannot spread TB bacteria to others.

26. Symptoms:
 TB bacteria most commonly grow in the lungs, and can
cause symptoms such as:
A bad cough or longer pain in the chest.
 Blood in sputum.
Weakness.
Weight loss.
Fever.
 Sweating at night.

27. Diagnosis:
 Diagnosing active tuberculosis based only on signs and
symptoms is difficult.
 A chest X-ray and multiple sputum cultures for acid-fast
bacilli.
 A definitive diagnosis of TB is made by identifying M.
tuberculosis in a clinical sample (e.g., sputum, pus, or a tissue
biopsy).
 Nucleic acid amplification tests (PCR techniques) may allow
rapid diagnosis of TB.

28. Tuberculin skin test:
 A tuberculin skin test (also called a Mantoux tuberculin test) is
done to see if you have ever been exposed to tuberculosis (TB).
 The test is done by putting a small amount of TB protein
(antigens) under the top layer of skin on your inner forearm.
 If you have ever been exposed to the TB bacteria (Mycobacterium
tuberculosis), your skin will react to the antigens by developing a
firm red bump at the site within 2 days.
 The TB antigens used in a tuberculin skin test are called purified
protein derivative (PPD).
 This is a good test for finding a TB infection.

29. Tuberculin skin test:
or
Mantoux tuberculin test

30. Treatment:
 The only available vaccine is Bacillus Calmette Guerin
(BCG).
 BCG is prepared from a strain of the attenuated (virulence-
reduced) live bovine tuberculosis bacillus.
 It is the most widely used vaccine worldwide, with more than
90% of all children being vaccinated.
 The immunity it induces decreases after about ten years.
Drug therapy:
Antibiotics used to kill the bacteria.
Isoniazid, rifampin, ethambutol and streptomycin
generally used to treat TB.

31. Emerging diseases – H1N1(Influenza virus)

32.  Influenza viruses are RNA viruses, belong to the family
Orthomyxoviridae.
 Three different types of influenza viruses.
 Influenzavirus A
 Influenzavirus B
 Influenzavirus C

33.  The influenza A virus can be subdivided into different
serotypes based on the antibody response to these viruses.
 H1N1, which caused Spanish Flu in 1918, and Swine Flu
in 2009.
 H2N2, which caused Asian Flu in 1957.
 H3N2, which caused Hong Kong Flu in 1968.
 H5N1, which caused Bird Flu in 2004

34. H1N1 Virus structure:
 The virus particle is 80–120 nanometers in diameter and
usually roughly spherical.
 Virus envelope containing two main types of glycoproteins i.e
Hemagglutinin (HA) and neuraminidase (NA).
 M2 (matrix protein 2) is the other protein found below the
envelop.

35.  Influenza viruses have a (-) single-stranded RNA
genome that encodes all the viral proteins.
 This genome is divided into eight segments. Each segment is
coated with NP (nucleoprotein) to protect the RNA.
 RNA is replicated by a polymerase composed of three
different proteins: PB1, PB2, PA.

36.  HA (hemagglutinin) allows the virus to bind to epithelial
cells in the respiratory tract by binding to sialic acid on
the cell surface.
 Haemagglutinin causes red blood cells to clump together
and binds the virus to the infected cell.
 NA (neuraminidase) helps newly made viruses release
from infected cells

38. Symptoms:
 Influenza, commonly known as "the flu", is an infectious
disease caused by an influenza virus.
 The most common symptoms include:
 a high fever,
 runny nose,
 sore throat,
 muscle pains,
 headache,
 coughing.

39. THANK YOU