This document discusses the genus Mycobacterium, focusing on Mycobacterium tuberculosis and Mycobacterium leprae. It describes their characteristics such as being acid-fast, non-motile, and aerobic bacteria that grow optimally at 37°C. It also discusses tuberculosis as a disease caused by M. tuberculosis, how it is transmitted via inhaled droplet nuclei, and its associated symptoms. Laboratory techniques for diagnosing tuberculosis using sputum samples and the Mantoux reaction are also summarized.

1. By s,manivannanmmmmmm
MANIVANNAN S
I-M.SC., MICROBIOLOGY
MEDICAL BACTERIOLOGY
DEPT OF MICROBIOLOGY
PERIYAR UNIVERSITY

2.  The genus Mycobacterium contains Gram
positive ,branched , filamentous bacterium.
 It containing two medically important species
 Mycobacterium tuberculosis
 Mycobacterium leprae
 First species of the genus discovered by
HANSEN – in 1857 [Mycobacterium leprae]
 Myco.tuberculosis- discovered by Robert koach

3.  It is a Acid Fast Bacterium [AFB]
 Thin,slender,curved & branched bacilli.
 Non - motile
 Non – capsulated
 Non – spore forming

4.  Aerobic
 Facultative anaerobe
 Growth temperature-15 ◦c to 45◦c
 Optimum temperature -37◦c
 PH-6.8 to

5.  The organism unable to grown in normal
cultural medium
 The medium enriched with egg,serum,potato
starch& blood
 LJ medium [lowenston jenson]
 Dorget’s medium
 Powlosky medium [pototo starch]
 Tarchis medium[blood]

6.  Leoffler’s medium [serum]
 The most repeatly medium in laboratory for
cultivation of myco.tuberculosis is LJ on
medium

8.  It is a slow growing organism
 Multiplication of time 14-18 hours
 Inoculated LJ medium with
myco.tuberculosis,after two weeks incubated at
37
 Irregular ,margined ,pale yellow colour were
seen.
 Not easily to emulsified.

10.  Niacin test
 Neutral red test
 Catalase &peraxidase test
 Aryl sulphadase test
 Amidase test

16.  The organism possess cell wall antigen
‘’TUBERCULIN PROTEIN’’
 That is responsible for antigenic factor
 Tuberculin protein induce delayed type of
hypersensitivity reaction,the output of delayed
type of hypersenstiivity called
’TUBERCULOSIS’
 The delayed type of hypersensitivity was
discovered by ROBERT KOACH

17.  It is caused by a disese TUBERCULOSIS
 Mainly affected by humans.
 Guinea pig,dog,rabbit,sheep &horse are
resisitant to TB infection
 The organism acquired by inhalation of
DROPLET NUCLEI [dried dust particle
containing invertious organisms
 This droplet nuclei containing Myco,tuberculosis
cells

18.  This cells enterd into upper respiratory tract
due to improper condition of NATURAL
DEFFENCE MACHENISM
 Lower respiratory tract such that LUNG
 The organism reach the lower lope of lungs.The
lung containing macrophage is called
ALVEOLAR MACROPHAGE
 It’s carry out phagocytosis procescs and
engulfment of Myco.tuberculosis cells

19.  But unable to destroy.The organism
multiplying instead of killing.
 At this stage macrophage release in biological
substances.It activate CD4,TH cells-these cells
releasing interlukin-1,alpha-interluin,alpha
necrosis factor these are attached with
macrophage cells
 At the same time ,It will attack
polymorphoneuclear cells,B-lymphocytes, T-
lymphocytes attaced the site of infections.

20.  This tuberculin nodulin infected lower lung
lope and without any treatment within 8-12
weeks.but leave a tiny cavity
 Later the same organism is may be reinfected it
may be lead out allergy in delayed type of
hypersenstivity reaction
 Cell mediated immunity power poor cases
more susceptable to Myco.tuberculosis

21.  The nodular structure on HYLAR
LYMPHNODE called GHON FOCUS.
 Joining ghon foccus called PRIMARY
COMPLEX It leads caseation necrosis factor.It
release necrosis particle these lead irrudation
of lung.cough bring out rusty sputum with
blood.

23.  Frequent cough,rusty sputum with blood
 Chest pain,respiratory tract difficulties
 Fever,faddigue,weight loss
 Night swetting
 Malaise
 Anorexia
 Hemoptysis

24.  Specimen – sputum
 The sputum sample is collected by a wide
mouth sterile container the sample should be
collected early morning before meals
 Within 2 hours of collection will bring it to
laboratory
 Containers should be leak-proof

25.  The organism not easily taken the stain at the
time of staining.
 Beceauze it possess MYCOLIC ACID on their
cell wall
 It is wax like substances
 The stain is decoulourized by 25% of H2SO4

28.  If the sputum sample is containing 1ooo
cells /ml the given result indicate possitive
 It carry on concentration method
 Also called petrof’s method

30.  MANTOUX REACTION

31.  Multiple drugs are available
 Bacteriastatic &bactericidal antibiotics for used
 Rifambicin-R
 Isoniazide-H
 Pyroziamide-Z
 Ethanebutol-E
 Streptomycin-S

32.  BCG- Vaccination
 A single intramuscular injection given after
immediate birth for all human childs in
individuals. It will confirm immunity more
than 15 years
 Myco.bovis –sub culture [GBPSA] can also used
as a vaccine.