This document discusses clinical microbiology and methods used in the field. It provides definitions of clinical microbiology as the study of bacteria and their relation to medicine. Key methods discussed include culture-based techniques of growing bacteria in controlled conditions to isolate, identify, and determine antibiotic sensitivity. Additional non-culture methods described are use of monoclonal antibodies, enzyme immunoassays, probes, polymerase chain reaction (PCR), and ligase chain reaction.
2. What is Clinical microbiology?
Definition
Clinical microbiology is the science or study of bacteria
and their relation to medicine and to other areas such as
agriculture and industry. Bacteria are single-celled
microorganisms which can live as independent organisms
or dependently like a parasite.
Clinical microbiologist use microscope to examine
smears of original samples to obtain early information.
3. USE OF CLINICAL MICROBIOLOGY.
Used in public and private Laboratories.
Used in Isolation & identification of different Disease
causing agent (Etiological Agent) Etiology: The
Science of finding causes.
Used in finding major pathogenic microorganisms.
Used in Cultivation and isolation of different
microorganisms and their comparison with other
normal Flora of the Body.
4. Clinical microbiology is the Field that Covers a very
Broad range of Testing Methods. The Methods that is
used for Isolation and identification of different
pathogenic and non-pathogenic organisms.
Clinical Microbiology is almost based on Culture
based methods and phenotypic methods for
identification of different Cultured Microbes.
5. CULTURE BASED METHOD
A microbiological culture, or microbial culture, is
a method of multiplying microbial organisms by
letting them reproduce in
predetermined culture medium under controlled
laboratory conditions.(temperature , pressure etc).
Microbial cultures are used to determine the type of
organism, its abundance in the sample being tested,
or both.
6. PHENOTYPIC BASED METHOD
Phenotypic based method are used to classify or
identify the organisms on the basis of their
Structure, gram stain, acid fast reaction etc.
7. CLINICAL LABORATORY TESTING:
The old and Classical Methods are even used in this
latest era like Koch’s and Pasteur Experiments and
this are helping the modern world very well.
In laboratory Errors and Omissions may occur but as
per the rule of microbial laboratory the clinical
microbiologist perform the test several time to get an
accurate result.
8. CULTURE METHOD
purpose: (Modern)
To Isolate Bacteria in pure Culture.
Demonstrate their Properties.
Determine Sensitivity to antibiotics.
Estimate viable Counts.
9. WHAT WE DO IN CULTURED METHOD
Cultured of bacteria from samples. (Wound,
Diarrhea, Soil, Sweats, Infection, Saliva etc)
A culture media contain Growth Medium that
Nourishes the bacteria. (Different Culture Media are
Used for different Bacteria).
The Bacteria which were grown in the Culture media
will form colonies.
The microbiologists will took the positive samples
that are larger in numbers and evaluate it for further
testing (Antibiotic Sensitivity).
10. CULTURE MEDIA
A culture media is a special medium used in
microbiological laboratories to grow different kinds
of microorganisms. A growth or a culture medium is
composed of different nutrients that are essential for
microbial growth.
Major Types of Culture Media:
1. Solid Culture Media. (Agar for Pure Culture)
2. Semi Solid Culture Media.
3. Liquid Culture Media.(For blood Culture)
11. TYPES OF MEDIA
BASAL MEDIA
Typical Growth Media That don’t need enrichment factors Staphylococcus and
Enterobacteriaceae are grows in it.
ENRICHED MEDIA
The media are enriched usually by adding blood, serum or egg. Streptococci grow in
blood agar media (Lowenstein-Jensen media)
SELECTIVE MEDIA
These media favor the growth of a particular bacterium by inhibiting the growth of
undesired bacteria and allowing growth of desirable bacteria. ( MacConkey agar,
Lowenstein-Jensen media, tellurite media).
TRANSPORT MEDIA
These media are used when specie-men cannot be cultured soon after collection.
Examples: Cary-Blair medium, Amies medium, Stuart medium.
STORAGE MEDIA
Media used for storing the bacteria for a long period of time.
Examples: Egg saline medium, chalk cooked meat broth
12. NON CULTURAL METHOD
MONOCLONAL ANTIBODIES
An Antibody that recognize only a single antigen.
(binds on only one epitope)
Monoclonal antibodies are produced using tissue
Culture techniques in which a mouse is immunized
multiple times with specific antigen that the mouse
produce more monoclonal antibodies.
The selective monoclonal antibodies are then used to
fight several pathogens in different animals.
14. Serum:
Pale yellow fluid that is derived from animal or humans blood that contain no clotting factors and Blood
cells.
Antiserum
A blood serum containing antibodies against specific antigens, injected to treat or protect against
specific diseases.
15. LATEX AGGLUTINATION TEST
The latex agglutination test is a clinical method
to detect certain antigens or antibodies in a variety of
bodily fluids such as blood, saliva, urine or
cerebrospinal fluid. The sample to be tested is sent to
the lab and where it mixed with latex beads coated
with a specific antigen or antibody
16. ENZYME IMMUNOASSAYS
Enzyme immunoassays (EIA) are used to visualize
and quantify antigens. They use an antibody
conjugated to an enzyme to bind the antigen, and the
enzyme converts a substrate into an observable end
product.
17. PROBES
A probe is a single-stranded sequence of DNA or
RNA used to search for its opposite sequence in a
sample genome. ... The probe is labeled with a
radioactive or chemical tag that allows its binding to
be visualized. In a similar way, labeled antibodies
are used to probe a sample for the presence of a
specific protein
18. POLYMERASE CHAIN REACTION PCR
Polymerase chain reaction (PCR) is a method
widely used to rapidly make millions to billions of
copies of a specific DNA sample, allowing scientists
to take a very small sample of DNA and amplify it to
a large enough amount to study in detail
19. LIGASE CHAIN REACTION
The ligase chain reaction is an amplification process
that differs from PCR in that it involves a
thermostable ligase to join two probes or other
molecules together which can then be amplified by
standard polymerase chain reaction cycling