An overiew of medical microbiology for Clinical medicine , nursing community health , plaster technician diploma and certificate level

1. Walter Waswa Wakhungu
BSC.MLS,MPH/MSC MICRO CANDIDATE PWANI
UNIVERSITY
INTRODUCTION
TO
MEDICAL MICROBIOLOGY
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INTRODUCTORY LECTURE

2. Defining Microbiology
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• Medical Microbiology is the study of
microorganisms:
– Bacteria
– Fungus
– Parasites
– Viruses
– Most can only be seen with the microscope!

3. What is Microbiology
• Study of different
Microorganisms
• Can be
Bacteria
Viruses
Parasites
Fungus
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4. Coverage of subject
• General
Microbiology
• Bacteriology
• Mycology
• Virology
• Parasitology and
entomology
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5. Microbes in Our Lives
• Microorganisms
are organisms that
are too small to be
seen with the
unaided eye.
• “Germ” refers to a
rapidly growing
cell.
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6. Naming and Classifying
Microorganisms
• Carolus Linnaeus (1735)
established the system of
scientific nomenclature.
• Each organism has two
names: the genus and
specific epithet.
• Are italicized or
underlined. The genus is
capitalized and the
specific epithet is lower
case.
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7. Microorganisms
Non-cellular organism
Prokaryotes
Eukaryotes
Others Prions Viroid
Fungi
Bacterium
Virus
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8. 1.Bacteria
• 10 times smaller
• Prokaryotes
• Peptidoglycan cell
walls
• Binary fission
• For energy, use
organic chemicals,
inorganic chemicals,
or photosynthesis
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9. Bacterial Cell Wall
.
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10. Figure 3-1. Various forms of bacteria, including single cocci, diplococci, tetrads,
octads, streptococci, staphylococci, single bacilli, diplobacilli, streptobacilli,
branching bacilli, loosely coiled spirochetes, and tightly coiled spirochetes.
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11. 2. Viruses
Viruses lack many of the attributes of cells, including the ability to
replicate. Only when it infects a cell does a virus acquire the key
attribute of a living system: reproduction
A viral particle consists of a nucleic acid molecule, either DNA or RNA,
enclosed in a protein coat, or capsid
Viruses are known to infect all cells, including microbial cells. Host-virus
interactions tend to be highly specific
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12. Viruses
• A virus is not a cell!
• Viruses are replicated
only when they are in a
living host cell
• Consist of DNA or RNA
core
• Core is surrounded by a
protein coat
• Coat may be enclosed in
a lipid envelope
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13. What are Viruses
• Viruses Dependent on
Host cells for necessary
functions and
Multiplication
• Intracellular
parasites
• Contain either
DNA or RNA
never both.
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14. 3. Prion
A kind of infectious protein that can resist the digestion of proteinase
The cellular form of the prion protein (PrPc) is encoded by the host’s
chromosomal DNA
An abnormal isoform of this protein (PrPres) is the only known
component of the prion and is associated with transmissibility.
Kuru, Creutzfeldt-Jakob disease (CJD), Gerstmann-
Sträussler-Scheinker disease, fatal familial insomnia
, and Bovine spongiform encephalopathy (BSE)
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15. 4. Parasitology
• Parasitology is the study of parasites .and their
interactions with their hosts.
• The science of parasitology has a long history and
has its roots in zoology, with its emphasis on the
identification and classification of parasites and
of life cycles,
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16. Taxonomic classification of parasitic
organisms
• Parasites are classified into 2
protozoa (unicellular)
metazoa (multicellular
• Protozoan (unicellular) parasites are classified according to
morphology and means of locomotion.
• Metazoa (multicellular) include the worms (helminths) and
arthropoda (posses an external skeleton) e.g. ticks, lice
• Note that the genus starts with a capital letter and the species is
always written in italics, e.g. Plasmodium falciparum, Giardia
lamblia
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17. 5. Fungi
• Considerable variation
in size.
• Internal Molecular
system
• Well defined cell wall
composed of
polysaccharides
• Gaining importance in
Immunosupressed
patients and increased
use of Antibiotics
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18. Cont..
• In medicine we classify fungi based on degree
on tissue involvement and mode of entry
1. superficial
2. Cutaneous mycoses-dermatophytes
3. Subcutaneous mycoses
4. Systemic
5. Opportunistic
6. Fungal toxins and allergies
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19. Equipments and reagents used in
study of microbiology
Microscope
• Magnifies
• Diferent types
Centrifuge
• Sediments particles eg
cells bacteria casts and
parasites suspended in
fluids by exerting a
force greater that of
gravity.
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20. Equipments and reagents used in
study of microbiology
Autoclave
• Sterilization
• Temperature of saturated
steam at atmospheric
pressure is approximately
100 c
Colorimeter
• Measures hb and other
substances in the body
which can alter in
concentration in disease
and during treatment
Incubator
• Controlled temperature
for bacteriological
culture, blood
transfusion,haematology
and other tests
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21. LABORATORY CLASSIFICATION
Classified based on the
biosafety
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22. Lab safety
• All laboratories post
signs regarding
safety
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23. • Safety hoods are used to avoid splashing
and inhaling possible pathogens.
Laboratory safety

24. Protect Yourself from
Infections
• Certain infections
can infect you
• Eg HIV, Hepatitis B
infections,Tubercul
osis,Many
respiratory
infections
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25. Protect others from Infections
• Sterilization
• disinfection
• Inceneration
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26. •The end
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