Lecture 1: Chapter 1
AsturiaNOTES
Microbiology: The Science of Microbiology
Microbiology
 The study of microorganisms
o Microorganisms: a large and diverse group of microscopic organisms that exist as
single cells or cell clusters
 Therefore, microorganisms can be:
1 Unicellular – having one cell
2 Multicellular—having many cells
 Microorganisms also include viruses which ARE microscopic BUT ARE NOT
cellular
 Microorganisms collectively carry out more photosynthesis than by green
plants
Biological relationships
These are biological relationships that exist between two organisms.
1. Mutualism
 Is a biological relationship wherein BOTH parties
o Contribute to sustain the relationship
o Benefit from the relationship #RelationshipGoals
Lichens are an example of microbial mutualism. Lichens consist of a fungus + a
phototrophic partner, either an alga (eukaryote) or a cyanobacterium (prokaryote).
*Lichen = fungus + (alga OR cyanobacterium)
Phototrophic organism = organism capable of photosynthesis AKA make their own food
The phototrophic partner in the mutualistic relationship of is the primary producer and
the fungus provides the phototroph protection from destructive elements—giving shelter to the
alga or cyanobacterium. The fungus is also called the “mycobiont” of the lichen and the
phototrophic organism (alga, cyanobacterium) is also called the “phycobiont”.
Mutualism is also called symbiosis.
2. Parasitism
 A relationship in which a host provides the primary benefit to the parasite
o It is a biological relationship wherein one gives too much and the other receives too
much. And usually this happens at the expense of the host (#Hugot)
 The exchange operates primarily to the benefit of one party, the parasite.
In the laboratory, in order to isolate and culture a pathogenic parasite—usually a
bacterium or a virus—often require effective mimicry of the environment where they thrive AKA
dapat magaya sa laboratory set-up yung environment ng host para for the parasite to thrive
AND grow. This demand represents a major challenge to investigators.
Microorganisms are very heterogeneous in a way that they are very diverse. Animals,
like humans are only eukaryotic while microorganisms can be eukaryotic or prokaryotic.
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Lecture 1: Chapter 1
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Microbiology: The Science of Microbiology
MICROBIAL GROUPINGS
Microorganism are classified into four groups—Viruses, Prokaryotes, Prions, and Protists.
A. Viruses
Microscopic and acellular.
Cannot replicate on its own. Therefore, it CANNOT make viral protein on its own, too.
Contain nucleic acid—DNA or RNA—NEVER BOTH.
Technically, it is a non-living thing—it is a “particle” (viral particle). However, viruses gain
“life” when they infect cells.
 Can infect all kinds of cells—prokaryotic or eukaryotic. And sometimes, it can infect other
viruses, too.
o Bacteriophage—a virus that infects bacterial cells
o Virophage—a virus that infects other viruses
o Viroids—a virus that infects plant cells
 RNA viruses
1 The RNA is:
a Small
b Circular
c Covalently closed
d Single-stranded
e Rod-like in shape
f Not able to produce proteins because it does not have any
protein-encoding genes
g Replicated by the DNA-dependent RNA polymerase of
the plant host
h Shown to contain inverted repeated base sequences at
their 3’ and 5’ ends—a characteristic of transposable
elements—“transposons”—and retroviruses.
i Thus, viroids are believed to have evolved from
retroviruses whose internal sequences are deleted.
 Totally dependent on the host (plant) for its replication
 Host-virus interactions are HIGHLY SPECIFIC.
o A dog cannot acquire HIV!
 In the same line of reasoning, HIV cannot infect, for example, hepatocytes.
o And similarly, eating a vegetable infected by a plant virus will not be pathogenic to
humans!
o The existence of a broad range of viruses is reflective of the number of potential
host cells.




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Lecture 1: Chapter 1
Microbiology: The Science of Microbiology
 Viral particles are generally small and consists of a nucleic acid which is enclosed in a
protein coat—Capsid. The capsid protects the nucleic acid and facilitates attachment and
penetration of the virus to the host cell is sometimes enclosed by an envelope of lipids,
proteins, and carbohydrates.
o Enveloped virus—the capsid is enclosed by lipids, proteins, and carbohydrates
 The lipids, proteins, and carbohydrates originate from the cell membrane of
the host because the virus will just “bud off” from the host cell. The
“envelope” is not a part of the virus.
 Enveloped viruses do NOT destroy the host cell. It does not burst the host
cell.
 Examples:
1 HIV
a In HIV, the host cell is the CD4+ T-cell. In full-blown AIDS,
there is decreased level of CD4+ reaching as low as 20.
Tanong sa lecture: Since HIV is an enveloped virus,
therefore it does not destroy CD4. Pero, bakit bumababa
ang CD4 levels in AIDS?
i
o
Answer: Indirect mechanisms through the
involvement of the CD4 receptors through the
“homing theory” that states that CD4 T-cells that
are signaled by HIV are sent “home” to reside in
the lymph nodes. HIV-signaled CD4 receptors can
also cause apoptosis to CD4 cells (Cloyd et al.,
2001).
 The “sending home”/homing theory and the
induced apoptosis to the CD4 Tlypmhocytes decreases CD4 T-lymphocyte
count in the blood.
2 Flu
3 Dengue
4 Hepatitis B
Naked virus—the capsid is NOT enclosed by anything
 Naked viruses kill the host cell as the naked viruses exit from the host cell in
their journey to infect other cells. During this process, the cell bursts.
 Example of a naked virus:
1 Hepatitis A
a Transmitted through the oral-fecal route.
i Hepatitis E virus is also transmitted through this
route
 Mnemonic: Oral-fecal route: Ass Eaters get
A and E forms of hepatitis
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AsturiaNOTES
Lecture 1: Chapter 1
Microbiology: The Science of Microbiology
b
c
Can survive the strongly acidic pH of the stomach (pH 1 or
2) before going into the liver.
Once in the liver, Hep A virus can kill the hepatocytes by
making them burst.
i Hepatocytes that burst will release bilirubin
ii This bilirubin lodges in the skin
iii Once the bilirubin has set, it can cause jaundice
(yellowing)
*Question sa lecture: Bakit mas yellow ang pagka-jaundice ng patients with Hep A virus than
Hep B virus?
Answer: Since Hep B virus is an enveloped virus, it does not destroy the host—the
hepatocytes. Therefore, there is minimal jaundice only AKA subclinical jaundice only at
the level of the conjunctiva AKA conjunctival jaundice. And since Hep A virus is a naked
virus, and that as a rule, naked viruses destroy their host cells, therefore Hep A virus destroys
hepatocytes causing a lot of bilirubin to be released—this causes very obvious jaundice.
Virion = complete cell of viral proteins. A virion is what you call a virus in its virulent (infective)
phase.
Viral Replication
 Inside the cell, viral nucleic acid redirects the host’s replicative machinery so that the virus
can be replicated.
o In some cases, genetic information from the virus is incorporated as DNA into the
chromosome of the host.
o In some cases, the viral genetic information can serve as a basis for cellular
manufacture and release copies of the virus.
 This process calls for replication of the viral nucleic acid and production of
specific viral proteins.
Maturation consists of assembling newly synthesized nucleic acid and protein subunits into
mature viral particles which are then liberated into the extracellular environment.
o
o
Some very small viruses require assistance of other viruses for their replication.
 Example: Hepatitis D virus
1 The delta agent, Hep D, is too small to code for even a single capsid
protein and needs help from Hep B virus for maturation and even
transmission.
2 Hepatitis D virus is an incomplete virus. It cannot successfully thrive
without Hepatitis B virus. Treatment for Hep D infections?
a Treat Hep B!
Some viruses are large and complex
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AsturiaNOTES
Lecture 1: Chapter 1
Microbiology: The Science of Microbiology

Examples
1 Mimivirus
a A DNA virus
b It infects Acanthamoeba, a free-living soil amoeba
c Encodes 979 proteins
i Encodes for the 1st four aminoacyl tRNA
synthetases ever found from a non-cellular being.
ii Encodes for enzymes for polysaccharide
biosynthesis.
2 Megavirus
a Marine virus
b Encodes for 1,120 proteins
c Larger than some bacteria
d Can be observed in stained preparations by light
microscopy
e Does not undergo cell division; does not contain ribosomes
(Of course? How can it undergo cell division if it’s not even
a “cell”? It’s a virus! Ang chakka ng author ng librong ito.)
B. Prions
 Prion = PRoteinaceous infectION
 Only kind of microbe among the 4 groups that DO NOT HAVE nucleic acids.
 They cause scrapie, a degenerative CNS disease in sheep.
o Local prion disease in the Philippines: In Capiz? (Borromeo MD, 2015)
 Has a normal isoform called PrPc
o Encoded by the host’s chromosomal DNA
o PrPc is a sialoglycoprotein
 Sialoglycoprotein = Sialic acid + glycoprotein
1 Glycoprotein = Carbohydrates + protein (BUT there are more
proteins than the carbohydrates)
o Molecular mass: 33k-35k Daltons
o The pathogenic, diseased isoform of the PrPc is the PrPSc or PrPcres
 PrPSc sa book. Pero sa lecture, ang diseased isoform daw is PrPcres so ilalagay
ko na lang dito both.
Features
Detergent
solubility
PrPc (normal isoform)
PrPSc/PrPcres (pathogenic
isoform)
Soluble
Not soluble
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AsturiaNOTES
Lecture 1: Chapter 1
Microbiology: The Science of Microbiology
Susceptibility to
proteases
Structure
 PrPC
o
o
(1)
Susceptible
Partially susceptible
Alpha-helix (2◦ structure)
Beta-helix (2◦ structure)
Expressed on the surface of neurons via a glycosylphosphatidyl inositol anchor
in both infected and uninfected brains.
A conformational change occurs in the prion protein, changing it from its normal or
cellular form PrPC to the disease-causing form PrPSc/cres.
PrPc
Normal isoform
“conformational change or prion infection”
(2)
PrPSc/cres
Pathogenic isoform
“Recruits
and converts”
(3) other PrPcs
“to become”
(4) PrPSc/cres
Thus, prions replicate using the normal isoform as substrate that is present in the host.
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AsturiaNOTES
Lecture 1: Chapter 1
Microbiology: The Science of Microbiology
Human prion diseases are unique in that they manifest as sporadic, genetic, and
infectious diseases. The study of prion biology is an important emerging area of biomedical
investigation as there is much to be learned. PrP means Prion Protein.
Type
Acquired
Sporadic
Familial/Genetic
Human Prion Diseases
Name
Variant Creutzfeldt-Jakob Disease
Kuru
Iatrogenic Creutzfeldt-Jakob Disease
Creutzfeldt-Jakob Disease
Gerstmann-Straussler-Scheinker
Etiology
Ingestion of prion-infected
material
Source of infection unknown
Mutations of the gene encoding
for PrPc
Fatal familial insomnia
Creutzfeldt-Jakob Disease
Viruses vs. Viroids vs. Prions: A comparison and contrast
Viruses
Viroids
Prions
Obligate intracellular agents
Obligate intracellular agents
Abnormal form of cellular
protein
DNA or RNA, never both +
RNA only; no capsid (protein Protein only; No RNA nor DNA
capsid (protein coat)
coat)
C. Prokaryotes








Major characteristic: No Nucleus
Their DNA is circular
Only have 1 chromosome
Can live in diverse environments and even in extremes
o Highly acidic
o Highy salty
o High temperature
Purple bacteria = convert light energy to metabolic energy in the absence of oxygen
production
Cyanobacteria (blue-green algae/bacteria) = produce oxygen that can provide energy
through respiration in the absence of light
Aerobic organisms depend on respiration with O2 for their energy
Anaerobic organisms can use electron acceptors other than O2 in their respiration
o Many anaerobes carry out fermentation
 Energy is derived by metabolic rearrangement of chemical growth substrates.
Prokaryotes as a community
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Lecture 1: Chapter 1
AsturiaNOTES
Microbiology: The Science of Microbiology
If the organisms within a physically interconnected community are derived ONLY from a
single cell, therefore the community is a CLONE that may contain up to 108 cells. The clone is
conferred more properties than a solitary bacterium in the following ways.
 In the 108 cells, at least one cell will have a different variant of any gene of a
chromosome—this is genetic variability within the CLONE.
 In the 108 cells, it will form a mountain-like structure. Therefore, the ones at the exteriors
can be targeted first—dying first when faced with antibiotics or heavy metals—but
protecting those in the interiors of the mountain-like structure.
o The protection can be due to extracellular polysaccharides.
 Large amounts of extracellular polysaccharides produced by the high number
of cells within the clone.
1 Scenario: Given an antibiotic with a dose equal to “X”, a single
bacterium would die. Given the same antibiotic with the same dose
equal to “X”, 100% of the CLONE will NOT die because of these
protective mechanisms.
Many bacteria exploit a cell-cell communication mechanism called QUORUM SENSING.
 Quorum sensing
o For the regulation of the transcription of genes whose protein products are involved
on diverse physiologic processes such as:
 Bioluminescence
 Plasmid conjugal transfer
 Production of virulence determinants
o Depends on the production of one or more diffusible signal molecules called
autoinducers or pheromones that enable a bacterium to monitor its own cell
population density.
 This production of autoinducers or pheromones is an example of a behavior
typical to multicellular beings.
A distinguishing characteristic of prokaryotes is their capacity to exchange small packets of
genetic information.
 This information is carried on plasmids
o A small and specialized genetic elements that are capable of replication.
o In some cases, plasmids may be transferred from one cell to another.
 This plasmid transfer may spread specialized genetic information through a
population.
1 Particularly “special” of this spread of specialized genetic information
is the spread of drug resistance plasmids that render diverse
bacteria resistant to antibiotic treatment.
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Lecture 1: Chapter 1
Microbiology: The Science of Microbiology
The survival strategy of a single prokaryotic cell line may lead to a range of interaction with
other organisms.
 These may include symbiotic relationships illustrated by complex nutritional exchanges
among organisms within the human gut.
o These exchanges benefit both the
 Microorganism
 Human host
 Parasitic interactions can be detrimental to the host.
 Advanced symbiosis or parasitism can lead to loss of functions that may not allow growth of
the symbiont or the parasite independent of its host
o Symbiont = organism living in symbiosis, usually, the smaller of the two organism in
the symbiotic relationship
 If it is the “smaller” one, therefore in a human-microbe symbiosis, the
symbiont is the microbe or bacteria :P
o For example of loss of functions:
 The Mycoplasmas
1 Parasitic prokaryotes that have lost the ability to form a cell wall
a Adaptation to this?
i Harbor a substantial quantity of cholesterol (from
the host) to be incorporated into their cell
membranes para kunyari may cell wall na sila yun
nga lang, hindi made of peptidoglycan but made of
cholesterol.

The Chlamydiae and Rickettsiae
1 These bacteria are extremely small, so small, they become obligate
intracellular parasites.
2 They depend on the host cell for many essential metabolites and
coeznymes.
a This dependency as exhibited by the Chlamydiae and
Rickettsiae is a consequence of the “loss of function”—
AKA—them not possessing the typical bacterial size.
i Since they are small, they cannot house a big
genome. Therefore, their genome contains fewer
genes.
 Fewer genes = fewer proteins
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AsturiaNOTES
Lecture 1: Chapter 1
Microbiology: The Science of Microbiology
o
Fewer proteins = get the proteins
from the host!
 How
to
access
these
proteins?
  Become an obligate
intracellular parasite
Theory of Endosymbiosis
The most widely distributed examples of bacterial symbionts appear to be chloroplasts and
mitochondria—the energy-creating organelles found eukaryotes. According to the theory of
endosymbiosis, mitochondria and chloroplasts are endosymbionts—prokaryotes that
established and maintained a symbiotic relationship with an ancestral eukaryotes.
 The eukaryote conferring physical protection to the endosymbiont and the endosymbiont
providing the eukaryote with energy
Pieces of evidence that support this theory:
1. Eukaryotic organellar structures like the Golgi and Endoplasmic Reticulum cannot
replicate on its own but the Mitochondria can just like prokaryotes.
2. Eukaryotic organellar structures’ (like the Golgi and Endoplasmic Reticulum)
sedimentation rate is measured at 80 Svedbergs while the Mitochondria’s sedimentation
rate is at 70 Svedbergs just like prokaryotes.
3. Eukaryotic organellar structures do not like the Golgi and Endoplasmic Reticulum do not
have their own DNA but the Mitochondria have their own DNA just like prokaryotes.
*With all these similarities that mitochondria share with the prokaryotes, it has been touted that
mitochondria have originated from a prokaryotic ancestor.
Classification of Prokaryotes
Useful criteria may be structural, physiologic, biochemical, or genetic.
Endospores (or simply spores) are specialized cell structures that may allow survival in
extreme conditions.
 Endospores are useful structural criteria for classification because well-characterized
subsets of bacteria form spores
o There are three bacterial genera that produce endospores:
 Sporosarcina
 Clostridium
 Bacillus
o However, only Clostridium and Bacillus are the clinically important ones.
 Clostridium (Clos=sounds like “close” = no oxygen = ANAEROBE)
 Bacillus (Bacillus=Bae-cillus=BAE=Bacillus is AEROBE)
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Microbiology: The Science of Microbiology
 Some bacterial groups can be effectively subdivided on their ability to ferment specified
carbohydrates.
o This is a biochemical criterion.
 Another biochemical test is the Gram stain, which proves to be an effective
and swift criterion for classification because response to the stain is reflective
of FUNDAMENTAL and COMPLEX differences in the bacterial cell surface that
divides many groups of bacteria into two:
1 Gram-positive positive that color PURPLE in the gram stain
2 Gram-negative bacteria that color RED/PINK in the gram stain
o However, this may be ineffective when applied to other bacterial groups that may
lack any fermentative capability.
Eubacteria (Bacteria) and Archaebacteria
What is the major difference between bacteria vs. archaebacteria?
1. Cell Wall
 Bacterial: Peptidoglycan (Murein)
 Archaebacterial: Pseudopeptidoglycan (Pseudomurein)
2. Knowledge
 Bacterial: Very much studied
 Archaebacterial: Our knowledge is limited because Archaebacteria thrive in extreme
environments where it is hard to reach.
o Some archaebacterial representatives are killed by contact with atmospheric O2.
o Some only grow in temperatures exceeding 100degC.
o Halophiles, a group of archaebacteria that requires very salty environment for
them to grow.
o Thermoacidophiles, a group of archaebacterial that very acidic and very hot
environment for them to grow.
3. Presence of Introns
 Introns—segments of genes that Interrupt informational DNA. Introns are not encoded.
Therefore, they are considered to be non-functional DNA. The Exons are the ones that are
Encoded—capable of producing protein products.
 Bacterial: Present.
 Archaebacterial: Present and according to molecular data, introns of archaebacteria are
much alike with the introns of eukaryotes.
o This suggests that eukaryotic nucleus may have arisen from an archaebacterial
ancestor
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Lecture 1: Chapter 1
Microbiology: The Science of Microbiology
D. Protists
The protista is a group of microorganisms that is the most biodiverse of all the microbial
groups (VPPP). The protista includes:




Algae
Protozoa
Fungi
Slime molds
Mnemonic: PAFS (as in like “paps”)
The “true nucleus” = eukaryotes (Eu=true; karyon=nucleus). This nucleus is only one of
their distinguishing features. The membrane-bound organelles, the microtubules, and the
microfilaments of eukaryotes form a complex intracellular structure unlike that found in
prokaryotes.
Features
Motility
Nucleus-ER interaction
Method of reproduction
Sedimentation rate
Diploidy
Eukaryotes vs. Prokaryotes
Eukaryotes
Flagella/Cilia
Present
True cell division: Mitosis
80s
Present (haploid+haploid
cellular state). Most of
eukaryotes live most of their
lives in the diploid state.
Prokaryotes
Flagella/Cilia
Not present
Binary fission/fission
70s
Absent
Algae
 “Algae” used to denote all organisms that produce O2 as a product of photosynthesis
 One subgroup of the “Algal” group is the blue-green algae—now classified as bacteria—
the blue-green bacteria AKA the cyanobacteria
o As bacterial organisms, they are prokaryotic.
 Therefore, the cyanobacteria are now declassified from the “algal” group
despite their capability to photosynthesize.
 In present times, an organism is considerd to be an “alga” if it meets the following criteria:
o It must be photosynthetic
 Must contain the photosynthetic pigment—chlorophyll that must be located
in the chloroplast—the photosynthetic organelle.
o It must be eukaryotic
o It can either be unicellular or multicellular
 But many algal species are unicellular microorganisms
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
Kelps of brown algae—an extremely large multicellular alga
 Some algal species produce toxins that are poisonous to humans and other animals.
o Dinoflagellates—a species of alga that is unicellular—can cause algal blooms that
can cause red tides.
 Red tides can be caused by the dinoflagellate Gonyaulax. Gonyaulaxinduced red tides are serious because Gonyaulax produce neurotoxin such as
saxitoxin and gonyautoxin that can accumulate in shellfishes (example:
clams, mussels, scallops, oysters) that eat Gonyaulax.
1 Ingestion of these shellfish species by humans results in symptoms of
paralytic shellfish poisoning—can be fatal.
Protozoa
 Major characteristic:
o Unicellular
o Non-photosynthetic (heterotrophic)
 Heterotroph—nutrition is met by organic compounds; food is not made by
itself
1 Heterotrophic mode of nutrition is a consequence of loss of
chloroplasts
a Because of this reasoning, it is thought that algae came
first before the protozoa.
 Primitive protozoal representatives appear to be flagellated and resemble the algal
morphology in many respects
o From these primitive flagellated protozoal species, the ameboid and ciliated types
have evolved;intermediate forms are known to have flagella at one stage in the life
cycle and then pseudopodia at another stage
 Sporozoa
o Strict parasites that are usually non-mobile
o Reproduce sexually and asexually in alternate generations by means of spores
Fungi
 Major
o
o
o
characteristic:
Non-photosynthetic (heterotrophic)
Multicellular
Possesses mycelium—branching and interlacing hyphal filaments
 The hyphal filaments exhibit cross walls that are perforated and allow free
passage of nuclei and cytoplasm that yields the end result  a coenocyte
or a syncytium = a multinucleated mass of continuous cytoplasm that is
confined within a series of branching tubes.
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These tubes are made of polysaccharides such as chitin which are
homologous (similar) to cell walls.
 The mycelial forms are called molds.
 The non-mycelial forms are called yeast.
o Though equipped with no mycelium, yeasts are easily recognized as fungi by the
nature of their sexual reproductive process and by the presence of transitional
forms.
1
Mycelial bacteria are called actinomycetes. However, despite the similarity in
morphology brought about by the presence of mycelium in both mycelial fungi and bacteria,
they are both unrelated.
Mycological phyla
 Chytridiomycota
 Zygomycota—the zygomycetes
 Ascomycota—the ascomycetes
o Ascomycota evolved from the phycomycetes
 Basidiomycota—the basidiomycetes
o Basidiomycota evolved from the ascomycetes
 Deuteromycota—the deuteromycetes (imperfect fungi)
Slime Molds
 Major characteristics:
o Presence, as a stage in their life cycle, of plasmodium—an ameboid multinucleate
mass of cytoplasm
 Analogous to the mycelium of a true fungus—plasmodium and mycelium are
both coenocytic.
1 In the mycelium: cytoplasmic flow is confined to the branching
network of chitinous tbes
2 In the plasmodium: cytoplasm can flow in all directions.
a This kind of flow causes the plasmodium to migrate in the
direction of its food source, frequently bacteria.
b In response toa chemical signal, cAMP, the plasmodium,
which is macroscopic in size, differentiates into a stalked
body that can produce individual motile cells.
i These cells can either be flagellated or ameboid
ii These cells initiate a new round in the life cycle of
the slime mold.
 The cycle frequently is initiated by sexual
fusion of single cells.
AsturiaNOTES by RAsturiano UST-FMS A-2019: #TheElusiveDoktora
August 12, 2015. Lecturer: Dr. Joey Borromeo—downloadable (for free!) at: www.theelusivedoktora.wordpress.com
Page 14 of 16
AsturiaNOTES
Lecture 1: Chapter 1
Microbiology: The Science of Microbiology
Reproduction of the slime molds via plasmodia can depend
on intercellular recognition and fusion of cells from the
same species.
 The growth of slime molds depends on nutrients provided either by a bacterial or
sometimes, a plant cell.
 Slime molds can produce very potent antibiotics.
 Slime molds are usually NOT pathogenic.
c
The slime mold life cycle:
Spores
will release
will germinate
to become
Myxamoebae
(gets
nutrition
from feeding
on E.coli)
Fruiting
bodies
will become
will become
will become
Fruiting
body
Plasmodium
will become
will become
Pathogenesis of microbes
 Viruses—integrate viral DNA into host
o Can cause viral sepsis, high grade fever
o Can cause tumors (ex: Cytomegalo virus)
 Prions—fold normal prion protein abnormally
o Can cause slower transmission of neuronal impulses
 Prokaryotes and Protists—due to pathogenic structures
o Endotoxins
 From gram-negative bacteria
1 Can cause fever and shock
2 Can cause hypoperfusion to organs
3 Can activate prostaglandin which can reset fixed hypothalamic
temperature—resulting to fever and shock AKA iatrogenic effect
AsturiaNOTES by RAsturiano UST-FMS A-2019: #TheElusiveDoktora
August 12, 2015. Lecturer: Dr. Joey Borromeo—downloadable (for free!) at: www.theelusivedoktora.wordpress.com
Page 15 of 16
Lecture 1: Chapter 1
AsturiaNOTES
Microbiology: The Science of Microbiology
In cases of bacteremia (bacte= bacteria; emia= in the blood; bacteria in
the blood), do NOT give high dose antibiotic because this will kill/lyse
bacteria in the blood releasing huge amounts of endotoxin that can elicit
undesirable effects—even death.
Peptidoglycan
 Can result in abscess formation

o
Question from the book
1. Which one of the following terms characterizes the interaction between a fungus and algae in
a lichen?
A—Parasitism
B—Symbiosis
C—Endosymbiosis
D—Endoparasitism
E—Consortia
2. Which one of the following agents lacks nucleic acid?
A—Bacteria
B—Viruses
C—Viroids
D—Prions
E—Protozoa
3. Which one of the following is not a protist?
A—Bacteria
B—Algae
C—Protozoa
D—Fungi
E—Slime Molds
4. Which one of the following agents simultaneously contains both DNA and RNA?
A—Bacteria
B—Viruses
C—Viroids
D—Prions
E—Plasmids
AsturiaNOTES by RAsturiano UST-FMS A-2019: #TheElusiveDoktora
August 12, 2015. Lecturer: Dr. Joey Borromeo—downloadable (for free!) at: www.theelusivedoktora.wordpress.com
Page 16 of 16
Lecture 1: Chapter 1
AsturiaNOTES
Microbiology: The Science of Microbiology
5. A 65-year-old man develops dementia, progressive over several months, along with ataxia
and somnolence. An electroencephalographic pattern shows paroxysms with high voltages and
slow waves, suggesting of Creutzfeldt-Jakob Disease. This disease is caused by which of the
following microorganisms/agents?
A—Bacterium
B—Virus
C—Viroid
D—Prion
E—Plasmid
6. Which of the following cannot be infected virally?
A—Bacteria
B—Protozoa
C—Human cells
D—Viruses
E—None of the above
7. Viruses, bacteria, and protists are uniquely characterized by their respective size. True or
False?
A—True mamang! Truth be told! Push! Pak! Trumalinda! Trots!
B—Wititit true! Pagsanjan False Mam! Maggi na!
8. Which of the following are prokaryotes?
A—Archaebacteria
B—Protozoa
C—Viruses
D—Prions
E—Fungi
9. Quorum sensing in prokaryotes involves
A—Cell-cell communication
B—Production of pheromones
C—An example of multicellular behavior
D—Regulation of genes involved in diverse physiologi processes
E—All of the above
AsturiaNOTES by RAsturiano UST-FMS A-2019: #TheElusiveDoktora
August 12, 2015. Lecturer: Dr. Joey Borromeo—downloadable (for free!) at: www.theelusivedoktora.wordpress.com
Page 17 of 16
AsturiaNOTES
Lecture 1: Chapter 1
Microbiology: The Science of Microbiology
10. Twenty minutes after ingesting a raw clam, a 35-year-old man experiences paresthesias of
the mouth and extremities, headache, and ataxia. These symptoms are the results of a
neurotoxin produced by algae called?
A—Amoeba
B—Blue-green algae
C—Dinoflagellates
D—Kelp
E—None of the above
-endReferences
1. Jawetz, Melnick, and Adelberg’s Medical Microbiology (26th edition)
2. Long Quiz 1 Samplex from 2014
3. How does HIV cause depletion of CD4 T-lymphocytes? A mechanism involving virus signaling
through its cellular receptors by Cloyd MW, et al. (2001).
4. Lectures notes by RAsturiano from Dr. Joey Borromeo – UST-FMS Dept. of Laboratory
Medicine: Microbiology
Downloadable for free at: www.theelusivedoktora.wordpress.com
For any corrections you may find, content or otherwise, email me at:
ram.ustmedicine@gmail.com
-THANKSAsturiaNOTES
By RAsturiano
#TheElusiveDoktora
AsturiaNOTES by RAsturiano UST-FMS A-2019: #TheElusiveDoktora
August 12, 2015. Lecturer: Dr. Joey Borromeo—downloadable (for free!) at: www.theelusivedoktora.wordpress.com
Page 18 of 16