MICROBIOLOGY NOTES

INTRODUCTION TO MICROBIOLOGY
AND PARASITOLOGY

COURSE OUTLINE
Definition of Microbiology &
Parasitology
Pioneers in the Science of Microbiology
and their contributions
Career fields in Microbiology and
Parasitology
What is Microbiology?
advanced biology courses
study of microbes (microbes are said to be
ubiquitous)
mikros = small, bio = life, logos = to study

Cellular Microbes Acellular Microbes

living microbes non-living microbes

e.g. bacteria, archaea, some algae and Infectious particles
some fungi e.g. viroids, prions, and viruses
 NOTES!
Eucaryotes – true nucleus, cell membrane
Procaryotes – does not have true nucleus
Microbiology helps in various elemental
cycles food for tiny animals.
Archaea. Lives in extreme environment
Cryophiles. Lives in extreme cold
environment.
Example of saprophytes are mushrooms.
Microbial Ecology. Relationship between
microbes and environment.
Anton Van Leeuwenhoek. Father of
Microbiology. He discovered protozoa in 1674
and bacteria in 1676.

PATHOGENS NON-PATHOGENS

microbes that do not cause disease

disease causing microbes
vast majority of microbes are
also called “germs”
nonpathogens.

3% percent of bacterias are pathogens

while 97% are non-pathogens. Indigenous
Microflora – microbes that live on in our
bodies. (Opportunistic Pathogens)
Pathogens can cause two categories of
disease:
1. Infectious Disease – once pathogen
enter a person’s body becomes an
infectious disease.
2. Microbial Intoxication – produces a
toxin in vitro and when the person
ingests the toxin it becomes a disease.
 WHY STUDY MICROBIOLOGY?
They are essential for life in the planet.
Photosynthetic algae and bacteria
It is also involved in decomposition of dead organism and waste product.
Saprophytes
Bioremediation – use of microbes to clean up waste

SIGNIFICANCE OF MICROBIOLOGY
Indigenous Microflora
Opportunistic pathogens
Microorganism supports life
Saprophytes or decomposers
Bioremediation
Links to food chain
Elemental Cycles
Biotechnology
Genetic Engineering
Cell Model
Many microbes play essential roles in various elemental cycles. Food for tiny
animals Aid in the digestion of food and produce beneficial substances. For
many years, microorganisms have been used as “cell models”; the more that
scientists learned about microbial cells, the more they learned about cells in
general.

NOTES!
Microbes are used in many industries
In genetic engineering, a gene or genes from one organism is/are inserted
into a bacterial or yeast cell; the cell that receives the new gene(s) is then
capable of producing the gene product(s) coded for by the new gene(s).
 FIRST MICROORGANISMS ON EARTH
Fossils of primitive microorganisms date back about 3.5 billion years
ago
Candidates for the first microorganisms on Earth are archaea and
cyanobacteria.
cyanobacteria – bacteria that obtains energy fr. Photosynthesis or
bacteria that is photosynthetic.
Infectious diseases of humans and animals have
existed for as long as humans and animals have
inhabited the planet. Earliest known account of
pestilence occurred in Egypt in about 3180 BC. 4.5
billion years ago 3.7 to 4 billion years ago 3.5 billion
years ago Earth was formed.Molecular fossilsCellular
fossils 900 to 600 million yearsAnimals ago appeared
100 thousand years ago Human existed.

PIONEERS IN MICROBIOLOGY

ANTON VAN LEEUWENHOEK

“Father of Microbiology”
Made many simple single-lens microscopes.
Observed animalcules” (bacteria and protozoa).
Discovered protozoa in 1674 and bacteria in 1676
*ABIOGENESIS – Spontaneous Generation, life came from non-living things.
*BIOGENESIS – life came from living things.
 LUIS PASTEUR

Investigated different fermentation

products.
Developed the pasteurization process.
Discovered life forms that could exist
without oxygen (anaerobes).
Developed several vaccines
including rabies and anthrax vaccines
Disproved spontaneous generation.
Discovered the infectious agents that
were causing the silkworm disease.
Made contribution to the germ theory
disease
Championed changes in hospital practice
to minimize spread of disease by
pathogens.

ROBERT KOCH

Made significant contributions to the

germ theory of disease
Discovered that Bacillus anthracis
produced spores.
Developed methods of fixing and
staining bacteria.
Developed methods to cultivate
bacteria.
Discovered Mycobacterium tuberculosis
which causes tuberculosis and Vibrio
cholera which causes cholera.
Tuberculin testing
Richard Petri – assistant or partner
 KOCH’S POSTULATE
A particular microbe must be found in all cases
of the disease and must not be present in
healthy animals or humans. The microbe must
be isolated from the diseased animal or human
and grown in pure culture in the laboratory.

The same disease must be produced

when microbes from the pure culture
are inoculated into healthy
susceptible laboratory animals *The
same microbe must be recovered
from the experimentally infected
animals and grown again in pure
culture.
LIMITATIONS:
Obligate intracellular pathogens or obligate intracellular
parasites.
Some organism are species specific
Ethical considerations
Synergistic Infections
Pathogenicity of some microorganisms is affected in vitro
Not all diseases are caused by microorganisms

JOHN TYNDALL

Provided the initial evidence that some of

the microbes in dust and air have very high
heat resistance
CAREERS IN MICROBIOLOGY
Agricultural Microbiology
Concerned with relationship between microbes and crops,
with an emphasis on improving yields and combating plant
diseases.
Biotechnology
Used in industrial microbiology which is concerned with
the uses of microbes to produce large quantities of
substances such as amino acids, beer, drugs, enzymes and
vitamins.
Environmental Microbiology
Application of Microbiology in ecology.
Medical and Clinical Microbiology
Aim to monitor and control the spread of diseases in communities.

Genetic Engineering
Involves technique that alter the genetic makeup of organisms
to produce hormones and pharmaceuticals, create totally new
substances.
Microbial Physiology
Use of microbial cells as cell models
Paleomicrobiology
Involves the study of ancient microbes through molecular
fossils.
Parasitology
parasitic protozoa
helminths
anthropods
Sanitary Microbiology
Includes the processing and disposal of garbage and sewage
waste as well as the purification and processing of water
supplies to ensure that no pathogen are carried to the consumer
by drinking water.
Veterinary Microbiology
Bacterial and viral disease of domesticated animals
 MICROORGANISM AND CAREER FIELDS

Bacteria Algae Protozoa Fungi Virus Bacteriology Phycology Algology

Protozoology Mycology Virology

1. BACTERIOLOGY
2. PHYCOLOGY
3. MYCOLOGY
4. PROTOZOOLOGY
5. VIROLOGY

MICROBIAL MORPHOLOGY AND CLASSIFICATION

HISTORICAL NOTES
Robert Hooke – honeycomb like structures in
a corke slice --- cell. Matthias Schleiden,
Theodor Schwann, Rudolf, Virchow –
zoologist, they have seen in a microscope a
cell.

WHAT IS A CELL?
Fundamental unit of any living
microorganism.
It exhibits basic characteristics of life.
Can grow, reproduce, response via
stimuli and metabolisms.
Cytology. Study of the structure and
function of cells.
EUKARYOTE

Algae, Protozoa, Fungi Cellular, has true nucleus

STRUCTURE OF EUKARYOTIC CELL

10-100 micrometers

1. CELL MEMBRANE
Encloses and holds the cell intact
Regulates the passage of nutrients, wastes product,
and secretions into and out of the cell. *SELECTIVE
PERMEABILITY
Extracellular. Outside the cell
Intracellular. Inside of the cell.
Phospholipid by Layer
Hydrophobic. Water fearing
Hydrophilic. Water loving

NUCLEUS
TRUE NUCLEUS , Nucleoplasm,
Chromosomes, Nuclear
Membrane
The command center of the cell
2 Types of RNA, Ribosomal
Ribonucleic Acid (rRna)
Transfer Ribonucleic Acid
(tRna)
46 chromosomes in humans.
“control center
NUCLEOLUS

Dark area in the nucleus where the

rRNA are manufactured.
rRNA manufacturing area
organelles are everything that is
stored in a cell

CYTOPLASM
A semi-fluid, gelatinous, nutrient
matrix.
Contains storage granules and a
variety of organelles where most
metabolic reactions occur.
Where organelles are
suspended or lumulutang.
Where metabolic mostly
occur.

RIBOSOMES
Consist of ribosomal RNA and
protein (enzymes).
Site of protein synthesis.
80 svedverg
ENDOPLASMIC RETICULUM

Smooth ER Without attached

ribosomes and plays a role in
lipid (fat) synthesis.
Rough ER With attached
ribosomes. Protein synthesis

GOLGI COMPLEX
Golgi apparatus or Golgi body
Completes the transformation of newly
synthesized proteins and packages
them for storage or export.
“packaging center”
Secretory Vesicles
Transfer Vesicles
Cistems
Transport vesicles from rough ER

LYSOSOMES OR PEROXISOMES
Contains lysozyme and other digestive enzymes. Breaks down foreign
cells.
Macrophage. It is an immune cell. It eats
bacteria (phagocytosis).
Peroxisomes are membrane-bound
vesicles where H202 is generated or
break down.
Converts H202 into water and oxygen.
Equivalent of mitochondria.
MITOCHONDRIA

Powerplants, powerhouse or
energy factories
ATP (energy currency of the
cell) molecules are produces
within mitochondria by
cellular respiration.

PLASTIDS
Membrane-bound structures
containing photosynthetic
pigments.
They are sites of photosynthesis.
Chloroplast are a type of plastid;
they contain chlorophyll.
Photosynthesis (sunlight, carbon
dioxide, water, sunlight, glucose
or oxygen).

CYTOSKELETON
A system of fibers throughout cytoplasm.
MICROTUBULES
MICROFILAMENTS
INTERMEDIATE FILAMENTS
Structural indignity, giving or provide,
shape of cells, cell division.
CELL WALL

Powerplants, powerhouse or
energy factories
ATP (energy currency of the
cell) molecules are produces
within mitochondria by
cellular respiration.

FLAGELLA AND CILIA

Membrane-bound structures
containing photosynthetic
pigments.
They are sites of photosynthesis.
Chloroplast are a type of plastid;
they contain chlorophyll.
Photosynthesis (sunlight, carbon
dioxide, water, sunlight, glucose
or oxygen).
STRUCTURE OF PROCARYOTIC CELLS
PC are 10x smaller than EC
Bacteria, cyanobacteria and archaea are PC.
Binary Fission are the replication of PC, the time required to
replicate from parent cell are called generation time.
0.2-2.0 micrometers

CELL MEMBRANE
Mesosomes are sites for cellular respiration in bacteria.
Mitochondria are equivalent of mesosomes in EC

CHROMOSOMES
Single, long, supercoiled DNA molecules.
“control center”
Contains genetic material

NUCLEOID
DNA- occupied space within a bacterial cell.
It does not have nuclear membrane so it does not
contain genetic material.

CYTOPLASM
Semiliquid containing a complex
mixture of all materials required
for metabolism.
Metabolic processes occur
RIBOSOMES
For protein synthesize
70 svedverg

CELL WALL
Provides strong structural support that prevents the cell fr. bursting or
collapsing.
Dominant part of PC
PEPTIDOGLYCLAN (composes of alternating NAM-NAG (n acetylmuramic
acid, n acetyl glucosamine acid) Gram Negative – small or thin
peptidoglycan Gram Positive – thick peptidoglycan

GLYCOCALYX
DNA- occupied space within a bacterial cell. It does
not have nuclear A slimy, gelatinous material
produced by cell membrane and secreted outside
the cell wall.
Protects cell from desiccation (leaking of the
cellular component of the cell).so it does not
contain genetic material.
2 types: slime layer (for bacteria to slide,
movement) capsule; for protection.

FLAGELLA
Primary function is for motility or self-propulsion and
eventually chemotaxis (movement) thru runs and
tumbles.
Thinner than flagella in EC.
SAME KINDS WITH THE EC
Components are; Basal Body Hook Filament *Flagellin
It allows 360 degrees rotation.
Rotating
 TESTING FOR MOTILITY
Stabbing a tin mass of cells into soft medium. *Proteus
Microscopically through hanging drop technique. *Vibrio Cholera

PILI
Hair-like structures, most often observed
on Gram-negative bacteria.
Also called fimbriae.
For attachment on cell linings.
For conjugation (process of reproduction
on bacteria; sex pili)

SPORES OR ENDOSPORES
Very rare
As a means of survival
Sporulation (spore formation)
A bacteria can be resistant to heat, cold and dying bc of this

CHARACTERISTICS OF BACTERIA
ENDOSPORE
Uses heat
Primary Stain: MALACHITE GREEN
Counterstain: SAFRANIN
Blue Color
FLAGELLAR
Primary stain: Carbolfuchsin
MOTILE MICROORGANISM
Those with FLAGELLA or AXIAL FILAMENT.
With SLIME
Most Spiral shaped, include some bacilli
 ACELLULAR INFECTIOUS AGENTS
VIRUSES, VIROIDS, AND PRIONS

PROPERTIES OF A VIRUS THAT MAKES IT NON-LIFE

1. Has DNA or RNA, not both only have
one, but living org. have both.
2. Unable to replicate
3. Does not divide thru MITOSIS, MEIOSIS,
or BINARY FISSION.
4. Lacks genes and enzymes necessary for
energy production, CAN’T SYNTHESIZE
PROTEINS
5. Depends on host for energy and nucleic
acid production

BASIC STRUCTURE
CAPSID – protein coat
CAPSOMERES – circular protein units
Genomes – located at the center [RNA or
DNA]
Outer envelope – COMPOSED OF LIPIDS
and POLSACCHARIDES;

SARS-CoV-2 they can come out from the

plasma/cell membrane of the host and
reproduce themselves and transmitted from
one organism to another

ORIGIN OF VIRUSES
1. Viruses existed before cells
2. Viruses came from cells they
cannot multiply without the
host cell; they need cell for
reproduction
 CLASSIFICATION OF VIRUSES

According to Nucleic Acid has something to do with their genetic

material/genome
Double-stranded DNA most viruses that has been classified has
Single-stranded DNA
Double-stranded RNA
Single-stranded RNA most viruses
that has been classified has
Shape of Viral Genomes located in the
center
Circular
Linear
Shape of Capsid, Number or Capsomere

Polyhedral/Icosahedron forms a geometric shape; 20 sides

Helical
Bullet-shaped
Spherical
Polyhedral (Adenovirus)
Spherical (Influenza)
Complex (Bacteriophages) have the thin fiber, sheath, tail; infects bacterial
cells.

Helical (Tobacco mosaic virus)

Presence of envelope
If a virus has an envelope, they can be easily transmitted from one
organism to another.
It makes the virus appear spherical or irregular and has spikes.
Part of the nuclear or plasma membrane of their host cell.
Acquired by the virus and escape through the cytoplasm of the host cell
and replicate and invade the next host cell.
BACTERIOPHAGES
They don’t invade the host
cell; they inject their nucleic
acid into the cell.

VIRULENT TEMPERATE

causes the lytic cycle

Causes the lysogenic cycle, their DNA remains
which means that
integrated to the bacterial cells, chromosomes,
the host cell is
generation after generation, but the moments
destroyed after/ or
that the person’s immune system weakens
die after injecting
that’s the time they will undergo the lytic cycle
nucleic acid

STEPS OF INASION OF VIRUS IN THE

BACTERIAL CELL

LYTIC CYCLE
1. ABSORPTION
attaches to a protein, polysaccharide, or the receptor on the
surface of the bacterial cell.
2. PENETRATION
The phage injects its DNA into the cell.
3. PROPHAGE FORMATION
The DNA enters the bacteria and dictates what happens inside
the cell
The virus will control the bacterial cell.
4. SPONTANEOUS INDUCTION
Production of the viral pieces or parts
Biosynthesis (the genes are expressed; overcomes the host cell;
the gene of the virus represents the whole organism/ host cell).
5. REPLICATION AND MATURATION
Assembly of the viral pieces or parts are arranged to complete to
produce the viral particle VIROIDS.
LYSOGENIC CYCLE
The phage DNA becomes a part of the
bacterial chromosomes causing the lytic
cycle to occur. So, each time lysogenic cell
undergoes binary fission, the phage DNA is
also replicated and is passed onto the
daughter cells.
Medical implication: the lysogenic cell can produce new gene products
that isn’t produced before.
Ex. Only lysogenic cell of the clostridium botulinum and vibrio cholerae
can produce the toxins necessary for the disease to occur in humans.
If these bacteria where not infected with phages, they won’t be able to
cause disease.

VIRUSES
Animal Viruses
Viruses that infect animals as well as humans
Latent Virus Infection
A situation in which virus is present in the body, but it remains dormant,
not causing any overt symptoms
Dormant: resting stage; not causing major symptoms
Ex. Herpes Zoster: painful skin rash with blisters; latent form of chicken
pox
It hides in the nerve cells and become inactive for awhile and when the
body weaken, the virus reactivates causing shingles which is the deadliest
part of the infection
Oncogenic Viruses
Causes cancer
Ex. Kaposi’s Sarcoma: Herpes Zoster Ex.
Epstein-Barr virus (EBV):
Nasopharyngeal carcinoma (NPC) Ex.
Cervical cancer: Human papillomavirus
(HPV) most especially for women Ex.
Leukemia: retro virus.
Human Immunodeficiency Virus
An enveloped (easily transmitted from
one person to another; lipids,
polysaccharides can be released through
budding),
double stranded RNA virus (retrovirus) known to have AIDS
Plant Viruses
Cause disease to economically important crops
Morphologically similar to animal viruses and have similar types of
nucleic acids
Transmitted through worms, infected seeds or contaminated tools used in
farming
Viroids (plants)
Short, naked fragments of single stranded RNA.
Interfere in the metabolism and the growth sometimes killing the plant.
Prions
Infectious proteins which cause fatal neurologic diseases in animals and
humans
Ex. Scabies (galis: rashes in dogs)
Ex. Creutzfeldt-Jakob disease (CJD) (humans)
They can’t be killed by pure physical agents rather they need a combination of
chemical and physical agents or higher toxic agents
Stanley B. Prusiner, American neurobiologist who coined the term “prion”
SARS-CoV-2
SARS-CoV-2 is the official, scientific name of the
virus, the germ that causes the disease COVID-
19
COVID-19 is the name of the disease – the fever,
cough, chills, and other symptoms that people
have when they are infected with the virus
SARS-CoV-2.
All viruses have two parts:
Genes that contain all the information needed
to make more virus copies.
Proteins that protect the genes and help the virus spread
Some viruses – SARS-CoV-2 is one of them – also have a third part: an
envelope made of special fats that protects the genes and proteins.
 CELL REPRODUCTION

Sexual Asexual

Single microorganism is the sole

Two parents give rise to
parentthrough binary fission they can
offspring
have offspring

Involves fertilization Does not involve fertilization

Involves meiosis Does not involve meiosis

Eukaryotes only Prokaryotes and Eukaryotes

Mitosis all the division of body cells

1. Interphase – where the chromosome is still preparing to divide
2. Prophase – when the prominent chromosomes are being
emphasized or you can already see in the slides in the microscope the
threads
3. Metaphase – where the chromatids start to align to the equator
4. Anaphase – separation
5. Telophase –daughter cells divide and produce two daughter cells
Nuclear division
Two genetically identical nuclei
Either haploid or diploid cells
Two daughter cells
Meiosis Division of Sex Cells
Only diploid cell
Changed to haploid
Gametes are produced
Four daughter cells
PHENOTYPIC CATEGORIES
PROKARYOTIC CELL REPRODUCTION
Through binary fission, one solo parent
divides into two identical cells.

TAXONOMY

CLASSIFICATION NOMENCLATURE IDENTIFICATION

NAMES according to
INTERNATIONAL
RULES.Study one specific
Assignment of NAMES
specie all over the world
according to
Arrangement of org. into Process of determining where
INTERNATIONAL
TAXONOMIC GROUPS isolate belongs. Isolate and be
RULES.Study one specific
on the different phylum
specie all over the world.
(microorganisms); belong in
one group but differ in
characteristics

SYSTEMS OF CLASSIFICATION

Five-Kingdom SystemROBERT
Three-Kingdom SystemCARL WOESE
HARDINGWHITTAKER

Kingdom Prokaryotae /Monera• bacteria•

Kingdom Protista• protozoa• Kingdom Fungi• Archaea• Bacteria• Eukarya
Yeast, molds• Kingdom Plantae• plants• Kingdom
Animalia• Mammals
BACTERIA
Characteristics that we can see
Genotypic: we can’t see but it is within us; behavior
1. Gram negative and have a cell wall
2. Gram positive and have a cell wall
3. Lack cell wall
Morphology
Has something to do with the shapes when you view
it in the microscope
Three basic shapes: 1. Round or spherical 2.
Rectangular or rod 3. Curved or spiral

1. COCCI
When they divide, the cells can remain attached
to one another giving it different morphological
arrangement.
Ex. Streptococcus pneumonia – named after the
shape of cells
a. Diplococci – 2
b. Streptococci – chain
c. Tetrad – 4
d. Sarcinae – 8
e. Staphylococcus – clusters or grape shape/kumpul-kumpol

2. BACILLI
Divide only across their short axis
Fewer groupings compared to cocci
a. Single bacillus – 2 micrometers
b. Diplobacilli
c. Streptobacilli – rod shaped or in rectangular shaped
d. Coccobacillus – combination of circular and rod shaped
3. SPIRAL
Have one or more twists, they are never straight
Ex. Vibrio cholerae
a. Vibrio
b. Spirillum
c. Spirochete

BACTERIAL SHAPE IS DEFINE BY HEREDITY

Passing of traits from one organism to another.

MONOMORPHIC – maintain single shape, most
bacteria PLEOMORPHIC – No cell wall [CWO
bacteria], L forms, example is MYCOPLASMAS

BACTERIAL SHAPE IS DEFINE BY HEREDITY

PROTOZOA, ALGAE, FUNGI

PROTOZOA
CHARACTERISTICS
Eukaryotic or Prokaryotic Eukaryotic
Protozoology, Protozoologist
F-K: Protista
Classified acc. To LOCOMOTION
3 Defining CHARACTERISTICS
1. Eukaryotic
2. Unicellular
3. Lack cell wall
SPECIAL STRUCTURES
1. PELICLES – replacement for cell wall, supports the microorganism
2. CYTOSOME – primitive mouth, for ingestion of food.
3. Contractile vacuole – pumps water out from the cell
4. . Pseudopodia, Cilia, Flagella – for movement
Two stages of life cycle:
1. TROPHOZOITE [motile, feeding, dividing stage] active
2. CYST [dormant, survival stage] [thick capsule and low metabolic rate]
Nutrition
1. Source of energy
2. Chemoheterotroph] use inorganic compound for their source of energy
3. Chemical compounds rather than light
4. Carbon source from organic compounds other than CO2

Symbiotic relationship
1. Parasitic
2. Mutualistic
Reproduction
1. Through schizogony
2. Through gametes
3. Through conjugation
Classification and Medical Significance
1. Ciliates

Balantidium coli [only ciliated protozoan that causes disease in humans]

2. Amebae
[ameboid movement] [phagocytosis- cell eating] [pinocytosis- cell
drinking]
Entamoeba histolytica [causes amebic dysentery]
3. Flagellates
move by means of whip-like flagella
exhibit a wavelike motion
ex. Trypanosoma brucei, Trichomonas vaginalis Trypanosoma cruzi
Giardia lamblia.
4. Sporozoa – spores are dormant
nonmotile protozoa

lack pseudopodia, flagella, cilia

ex. Plasmodium spp. [causes malaria] Toxoplasmosis gondii [causes
toxoplasmosis]
ALGAE
CHARACTERISTICS:
• Eukaryotic/Prokaryotic: Eukaryotic
• Study of is called: Phycology
• Person studying: Phycologist
• Five-Kingdom: Protista Classified according
to: Photosynthetic pigment
Features:

1. Pellicle – thickened cell membrane

2. Stigma / Eyespot – light sensing organelle
3. Flagella – for movement
Nutrition
Photosynthetic [photoautotroph]
Use energy from the sun, carbon dioxide, water, and
inorganic nutrients from soil
Reproduction/Life cycle
1. Alternation of generation
Classification
Green algae: Chlorophyta from the word chlorophyl
Red: Rhodophyta Golden / Yellow green: Chrysophyta
Brown: Phaeophyta
Dinoflagellates: Pyrrophyta
Significance
1. Basis of the food web
2. Production of atmospheric O2
3. Source of food, iodine, and minerals
4. Emulsifiers and stabilizers
5. Gelling agent for jam and agar
FUNGI
Member of a large group of organisms
that includes yeasts, molds, and
mushrooms
Classified in a kingdom separate from
plants, animals, and bacteria
CHARACTERISTICS:
Eukaryotic/Prokaryotic: Eukaryotic
Study of is called: Mycology
Person studying it is Mycologist
Five-Kingdom: Fungi

Classified according to: Mode of sexual reproduction

Defining characteristics:
1. Eukaryotic
2. Not photosynthetic
3. Cell walls contain chitin
4. Sexual and asexual spore
Special structure
1. Hyphae – long filaments of cells joined together [septate or aseptate
2. Mycelium / Thallus – mass of hyphae Hyphal growth
1. Growth of a Hypha from a spore
Nutrition
1. Chemoheterotroph
2. Absorptive
3. Saprophytes decaying matter
Reproduction
1. Budding
2. Hyphal extension
3. Formation of Spores allergens; spores are transmitted through dust and
accidentally inhale causing allergies
Reproduction
Spore
 Sexual
Asexual
Classification (Phyla)
Ascomycetes: Septate
Basidiomycetes: Septate
Chytridiomycetes: Aseptate
Zygomycetes: Aseptate
Deuteromycetes: Septate
Classification (Sexual Spores)
Ascomycetes : Ascospore
Basidiomycetes : Basidiospore
Chytridiomycetes : Oospore
Zygomycetes : Zygospore
Deuteromycetes :
None Classification (Asexual Spores)
Ascomycetes : Conidiospore
Basidiomycetes : Rare
Chytridiomycetes : Motile zoospore
Zygomycetes : Nonmotile sporangiospore
Deuteromycetes : Conidiospore
Classification
1. YEAST
Responsible for fermentation
Saccharomyces cerevisiae (ferments sugar to alcohol) (simple sugar to
CO2 and H2O)
Candida albicans (most frequently isolated from human clinical specimen)
mouth
2. MOLDS
Phytophtera infestans (potato blight mold)
Penicillium and cephalosporium antibiotics
Production of enzymes, cheese
3. DIMORPHIC FUNGI combination of the yeast and mold
37oC: yeast
In vivo: yeast
 25oC: mold
Ex.
1. Histoplasma capsulatum [causes histoplasmosis]
2. Sporothrix schenckii [causes sporotrichosis]
3. Coccidioides immitis [causes coccidioidomycosis]
4. Blastomyces dermatitidis [causes blastomycosis
5. Fleshy fungi [mushrooms] edible
Significance
1. Decomposition
For human consumption either in raw form or as used in industry
2. Antibiotics [penicillin and cephalosporin] Cyclosporine
MYCOSES causes by fungi
1. Superficial
outermost areas of the human body
2. Epidermis
usually acquired by direct contact skin to skin or open wounds
4. Superficial Dermatophytes
causes tinea infections
Ex.
a. Tinea pedis (feet)
b. Tinea unguium(nail)
c. Tinea barbae (face)
d. Tinea corporis (body)
e. Tinea crucis (underarm)
f. Tinea capitis (head)
g. Candida albicans (thrush or vaginitis)
opportunistic
4. Cutaneous
dermis and underlying tissue deeper
part of the system; blood, veins, nerves
exposure is common but infection is
rare
5. Systemic
 ainhalation or direct implantation
zygomycosis and mucormycosis
Rhizopus and Mucor
Cultivation
1. Sabouraud’s agar
preferred in isolating fungi from mixed sample
Therapeutics
1. Nystatin
2. Amphotericin B
Variations
1. Lichens
combination of Algae and fungus
2. Slime mold
fungal and amoeba character
Diagnostics
1. Dx for yeast: Biochemical test they use a lot of chemicals to confirm that
something is cause by yeast
2. Dx for molds: Macro and microscopic examination
3. Dx for other mycoses: Immunodiagnostic procedure including skin test
SUMMARY
1. Acellular agents
Viruses, Prions, Viroids
2. Cellular
Prokaryotes: Bacteria
Eukaryotes: Protozoa, algae, fungi

MICROBIAL GROWTH REQUIREMENTS

OUTLINE
Nutritional Requirements Moisture
Requirements Temperature Ph
Atmospheric Requirements Osmotic Pressure
Barometric Pressure
 NUTRITIONAL REQUIREMENTS

NUTRIENTS – refers to the various chemical compounds that organisms

utilize in order to sustain life. ESSENTIAL NUTRIENTS – Materials that the
organism is unable to synthesize but are require for sustaining life. needed
kasi di natin kaya iproduce

THE SIX MAJOR ELEMENTS

NEEDED BY BACTERIA
C - arbon
H - ydrogen
O - xygen
N - itrogen
S - Sulfur
P – hosporus

Energy Source /
LIGHT (photo) CHEMICALCOMPOUDS (chemo)
Carbon Source

PHOTOAUTOTROPH
Photoautotrophs are CHEMOAUTOTROPHcan produce
organisms thatuse light their own foods using
CarbonDioxidea
energy and otherchemicalobtains energy
uto]
inorganiccarbon to through chemosynthesisrather
produce than by photosynthesis.
organicmaterials.

PHOTOHETEROTROPHt
CHEMOHETEROTROPHthey use
OrganicCompou he consumers; they need
other organic compouns tolive
ndshetero] toconsume other
(EX: consume photoautotrops)
organisms forthem to live
 ATMOSPHERIC REQUIREMENTS OOMFA

Classifications according to relationship to oxygen:

OBLIGATE AEROBE
Needs oxygen to survive
[20-21% or room air]
Mycobacterium specie
OBLIGATE ANAEROBE
Grows in absence of oxygen
Clostridium spp.
MICROAEROPHILE
little to low only concentration of oxygen.
Requires O2 at 5%
Neisseria gonorrhea
Helicobacter Pylori
FACULTATIVE ANAEROBE
Grow with or without O2
0-21% O2
E. coli
kaya nilang mabuhay with or without oxygen
AEROTOLERANT ANAEROBE
Can grow equally well in absence of O2. Lactobacill
can live with oxygen but may limitation, higher than limitation,
mamamatay.
CAPNOPHILES
Grow better in the increased level of carbon dioxide.

TEMPERATURE REQUIREMENTS
THREE CARDINAL TEMPERATURES
1. MINIMUM GROWTH REQUIREMENT – at which microorganisms grow best
2. OPTIMUM GROWTH REQUIREMENT – below which, growth ceases
3. MAXIMUM GROWTH REQUIREMENT – above which, destruction occurs
Components of Microorganism affected by temperature:
Protein
Lipids
 OPTIMU
GROUP MINIMUM MAXIMUM
M

Psychrophile -5 10 to 20 30

Mesophile 10 20 to 40 45

Thermophile 25 50 to 60 113

Hyperthermophile 85 to 130 [geogemmabarossiiaka strain 121]

PSYCHRODURIC ORGANISMS
Survive or endure very col environment.
THERMODURIC ORGANISMS
Survive boiling
MESOPHILE
Human body temp

MOISTURE
All living organisms require water to carry
out their normal metabolic processes

PH
Acidity or alkalinity of solution.
OSMOTIC PRESSURE
Pressure that is exerted on a cell
membrane outside the cell.
OSMOSIS
Movement of solvent from lower area to
higher concentration.
Movement of solvent from higher
concentration to lower area.
TONICITY
Concentration on blood.
ISOTONIC SOLUTION
equal concentration, equal number of H and N. outside and inside.
Water leaves nor enter the cell.
HYPOTONIC SOLUTION
number of solute is lower compared inside to the cell, bursting,
CELL BURSTING.
Results in hemolysis or plasmoptysis
HYPERTONIC SOLUTION
Results in crenation plasmolysis.
lower no. of solvent, crenation – nangangyayat
OBLIGATE HALOPHILES
Grown on in salty environment
HALODURIC MICROORGANISMS
Do not prefer but are capable of living in salty environment.
Normal Atmospheric pressure [14.7 PSI]
BAROPHILES
Thrive in deep ocean
 PHYSICAL METHODS

STAGES OF MICROBIAL GROWTH

Bacterial Population and Growth Phases

LAG PHASE
Period of little or no cell division.
Last 1 hour or several days
Synthesize of enzymes
LOG PHASE
Begins to divide and grow
EXPONENTIAL GROWTH PHASE
Cellular reproduction is most active
STATIONARY PHASE
Slow growth rate
Death and growth is EQUAL.
Stable
DEATH PHASE
Logarithmic decline phase
Number of deaths exceeds the number of new cells.
INHIBITING THE GROWTH OF MICROORGANISMS IN VITRO
Two methods of MICROBIAL CONTROL
1. STERILIZATION
Massacre or complete destruction of all microorganisms.
Preparation of canned food
Microbiological culture media
Dry heat, steam under pressure, chemicals, radiation
DISINFECTION
Destruction or removal of pathogens from nonliving objects by physical
or chemical methods
Pasteurization, alcohol or bleach, UV light.
ANTISEPSIS
Destruction or removal of pathogens in the skin or other
tissue.
Iodine, alcohol
SANITIZATION
Disinfecting utensils used by publics.
Lowering microbial counts to safe public health levels.
MICROBICIDAL VERSUS MICROBISTATIC
MICROBICIDAL
Drug or chemical that kills or destroy microorganisms
MICROBISTATIC
Drug or chemical that inhibits growth and reproduction of
microorganisms.
SEPSIS
Presence of pathogens ASEPSIS
Absence of pathogens
ASEPTIC TECHNIQUE
Exclusion or elimination of pathogens
Handwashing, sterile PPE’s, sterile PPE’s, use of
disinfectants
ASEPTIC
Environment free of contamination • E.g. surgical field
HEAT
Most practical, efficient, inexpensive ACTION
Denatures proteins
Interferes with the integrity of the cytoplasmic membrane
and cell wall
disrupts the function and structure of nucleic acids HEAT
Microorganisms vary their susceptibility
Time, temperature, and mixture
E.g. using Bunsen burner, using an electric device
THERMAL DEATH POINT
Lowest temperature that kills all cells in a broth in 10
minutes.
Time it takes to completely sterilize
Higher temperature allows shorter exposure times.
DECIMAL REDUCTION TIME
Time required to destroy 90% of microbes
MOIST HEAT
Applied in the presence of moisture, more effective, faster, lower, heat
Denatures proteins, destroys cytoplasmic membrane
Boiling [exposure to material to 10-30 minutes] [unsafe drinking water,
materials for babies, food preparation and utensils]
autoclaving [121 degrees Celsius, 15 PSI 2 atm, 15-20 minutes]
use to pressure temp. to destroy spore formers.
[Clostridium tetani, clostridium botulinum]
Effective for oils, waxes, powders, and heat-resistant materials
Pasteurization, destruction of microorganisms that causes spoilage
without ruining the taste of liquid.
High Temperature Short Time HTST – 72 degrees Celsius for 15s
Ultrahigh-High Temperature UHT – 134 degrees Celsius for 1s
Thermoduric and thermophilic microorganisms survive pasteurization
Use for milk, ice cream, yogurt, fruit juices
DRY HEAT
Hot air, incineration
HOT AIR
160-165 degrees Celsius for 2 hours
170-180 degrees Celsius for 1 hour
Rubber, paper, and many types of plastics, may oxidize.

INCINERATION
To sterilize inoculating loops flammable
contaminated medical waste and diseases carcasses.
Bunsen burner and electric heating device.
COLD
Refrigeration or freezing
Slows growth of cultures and microbes in food
during
 Slow freezing, rapid freezing
For food preservation
Lyophilization or freeze dying [methods of preserving for many years]
Desiccation [proper wound dressing disposal, careful rolling of bed linens
and towels, damp dusting of furniture, wet mopping]
UV RADIATION
Passes readily through air slightly through air, slightly thru liquids, and
only poorly liquids, and poorly thru solids
[X- ray and gamma radiation] – beef pork, chicken, fruit, and vegetables
Ultrasonic waves [high-frequency sound wave to mechanically dislodge
organic debris on instrument and glassware
Filtration [heat sensitives materials such as antibiotics, vaccines, liquid
enzymes] [surgical masks and HEPA filters]
GASEOUS ATMOSPHERE
Wounds likely to contain anaerobes are opened
Gas gangrene debridement + antibiotics + Hyperbaric oxygen chamber.

PHYSICAL METHODS
HEAT
1. MOIST - [boiling, autoclaving, pasteurization]
2. DRY – [hot air, incineration]
COLD
1. Refrigeration
2. Freezing – [slow, rapid]
DESSICATION
1. LYOPHILIZATION (freeze-drying)
RADIATION
ULTRASONIC WAVES
FILTRATION
GASEOS ATMOSPHERE
 CHEMICAL METHODS OF MICROBIAL GROWTH

FACTORS THAT AFFECTS CHEMICAL

AGENTS
Prior cleaning of objects
Organic load - biologic substances
that contaminate certain
substance (e.g. blood)
Bioburden
Concentration
Contact time – more contact time
more disinfectant activity.
Physical nature – smooth surfaces are easier to disinfect
Temperature
pH
Stronger and more effective antimicrobial chemical agents are of limited
usefulness.

MOST RESISTANT
Prions – most resistant
Bacterial endospore
Mycobacteria – cell wall contains fatty acid
Cyst of protozoa
Active-stage protozoa – more active than cyst
Gram-negative bacteria
Fungi
Nonenveloped viruses
Gram-positive bacteria
Enveloped viruses – most susceptible
MOST SUSCEPTIBLE
Susceptible - they can’t grow if the drug is present. This means the
antibiotic is effective against the bacteria.
Resistant - the bacteria can grow even if the drug is present. This is a
sign of an ineffective antibiotic

MEASURE EFFECTIVENESS
PHENOL COEFFICIENT
measure of the bactericidal activity
of a chemical compound in relation
to phenol (carbolic acid)
a coefficient greater than 1.0
indicates that the agent is more
effective than phenol, and the larger
the ration, the greater the
effectiveness

ex. CHLORAMINE
S. aureus – 133.0
S. enterica – 100.0
USE – DILUTION TEST
measures efficacy of disinfectants and antiseptics against specific
microbes
measures efficacy of disinfectants and antiseptics against specific
microbes:
S. aureus
P. aeruginosa
S. choleraesuis
Process:
Researcher dips several metal cylinders into broth cultures of bacteria
and dries them at 37degrees celsius.
unable to kill E. coli - g (-) zone of inhibition is shown in S.aureus – g(+) P.
aeruginosa – most resistant
IN USE TEST
realistic but time-consuming method for determining the efficacy of a
chemical (Determines the efficacy of materials).
 TYPES OF DISINFECTANTS
1. PHENOL AND PHENOLICS
a) PHENOLICS
compounds derived from phenol
molecules that have been chemically
modified by the addition of halogens
or organic functional groups
TRICLOSAN – Phenol and safeguard
b) BISPHENOLICS

Composed of two covalently linked phenolics such as hexachlorophene,

orthophenylphenol and triclosan. ORHTOPHENYPHENOL – phenol in
Lysol TRICLOSAN – phenol in safeguard ACTION
Intermediate to low level disinfectants that denature proteins and disrupt
cell membranes. ADVANTAGE
Effective even in the presence of contaminating organic materials and
remain active on surfaces for a prolonged period.

DISADVANTAGE
Disagreeable odor and possible side effects.

2. ALCOHOL
Intermediate-level disinfectants which is effective as bactericidal,
fungicidal, and virucidal but ineffective against fungal spores or bacterial
endospores.
ACTION denature proteins and disrupt cytoplasmic membranes (same as
phenol).
DISADVANTAGE
They may not contact microbes long enough to be effective (because
alcohols evaporate rapidly).
EXAMPLE OF USE
70% to 90% alcohol – for example, Rubbing Alcohol
Swabbing the skin with alcohol prior to an injection (to disinfect the skin
which is the site of injection) 100% alcohol is not effective. It needs to be
diluted in aqueous solution.
Dilution – addition of water to reduce the
strength.
3. HALOGENS
Four very reactive, nonmetallic
chemical elements which are
intermediate-level antimicrobial
chemicals.
EFFECTIVE AGAINST:
Vegetative bacterial cells
Fungal cells
Fungal spores
Bacterial endospores
Protozoan cyst
Many viruses
Halogens include the following elements:
Iodine
Chlorine
Bromine
Fluorine – most electronegative element
Halogens belong to the Group 7 of the
periodic table.
ACTION
exact action is unknown but is thought to participate in denaturation.
a) IODINE TABLETS
used in the potability of water. Potable – microbial number is enough to
be safe for drinking MEDICAL USE:
Disinfectant, usually 2-7 %
Potassium iodide or sodium iodide and elemental iodine, dissolved in a
mixture of ethanol and water [tincture].
As an iodophor: an iodine containing organic compounds that slowly
releases iodine containing organic compounds that slowly releases iodine.
Surgery, burns, injections
Good example of an iodophor is polyvinylpyrrolidone [PVP]
Betadine – most effective antiseptic in medical practice.
b) CHLORINE TABLETS
Used in potability of water
Amount of residual chlorine to ensure bacteriological safety of water is 0.1
[parts per million. Chlorine Compounds
Calcium hypochlorite.
Sodium hypochlorite – bleach; most common and disinfect blood stain
Chlorine dioxide
Chloramine

c) BROMINE
Effective disinfectant in hot tubs bc it evaporates more slowly than
chlorine at high temp
Good alternative to chlorine
Has brown suffocating odor
d) FLOURINE
Antibacterial in drinking water and toothpaste
0.5 to 1 mg or L is the permissible limit of fluorine in drinking water.
DENTAL FLUOROSIS – excessive se of fluorine.
4. OXIDIZING AGENTS
High-level disinfectants ad
antiseptics that are particularly
effective against anaerobic
microorganism. E.G
HYDROGEN PEROXIDE Most
common, most effective in
inhibiting anaerobes in deep
wounds.
OZONE PERACETIC ACID

5. SURFACTANTS
“surface active”
Chemical that is reduce the surface tension of solvents becomes
more effective at dissolving solute molecule. e.g. soap
One end of soap molecule is hydrophobic and the other end is
hydrophilic.
Hydrophobic [water-fearing], Hydrophilic [water-loving]

6. HEAVY METALS
Low level bacteriostatic and fungistatic agents
E.g.
Silver nitrate – anti gonococcal (gonorrhea)
1% Silver Nitrate – used before in ophthalmia neonatorum
New: Erythromycin
Silver sulfadiazine – used in burns
Thimerosal – contains mercury; used in vaccine
Copper
7. ALDEHYDES
E.g.
2 solutions glutaraldehyde
More preferred, less toxic,
Used in cleaning medical equipment
Formaldehyde

8. GASEOUS AGENTS
High level chemical method that is used to sterilize heat and water
sensitive objects.
E.g.
Ethylene oxide – used in gas sterilization for heat sensitive materials
Propylene oxide
Beta- propiolactone

CHARACTERISTICS OF AN IDEAL CHEMICAL AGENT

Must kill pathogens within a

reasonable period and in specified
concentration
Not toxic to human tissues and not
corrosive and not destructive to
materials
Must be soluble to water and easy
to apply.
Inexpensive and easy to prepare for use
It must be stable
It must be fast-acting and have a broad antimicrobial spectrum
Broad spectrum – kills both gram positive and gram-negative organisms
Spectrum - range of microorganisms that are killed by antimicrobials.
Phenols Oxidizing Agents Aldehydes
Phenolics Hydrogen Peroxide Glutaraldehyde
Bisphenolics Ozone Formaldehyde
Alcohols Peracetic Acid Gaseous Agents
Ethanol Surfactants Ethylene Oxide
Isopropanolol Soap Propylene Oxide
Halogens Heavy Metals Beta-propiolactone
Iodine Silver Nitrate
Chlorine Silver Sulfadiazine
Bromine Thimerosal
Fluorine Copper
Ultimate
MICROBIOLOGY
QUIZ
MULTIPLE CHOICE QUESTIONS