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STUDY OUTLINE CHART
Chapter 1 - Microbiology: Then and Now
 Leeuwenhoek observes living bacteria and other
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microbes (animalcules).
Experimentation puts an end to the idea of
spontaneous generation.
Semmelweis and Snow pioneer investigations
into the source, cause, and transmission of
disease (epidemiology)
Jenner demonstrates that vaccination can
generate disease resistance.
Pasteur proposes the germ theory; Koch proves
the theory through his postulates.
Chapter 2 - The Chemical Building Blocks
of Life
 Matter is composed of elements, about 25 of
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which are essential to life; carbon, hydrogen,
oxygen, and nitrogen being most abundant.
An atom is the smallest unit of an element
having the properties of that element. The
atomic nucleus consists of protons (+) and
neutrons (no charge) surrounded by a “cloud”
of electrons (−).
Different numbers of neutrons form isotopes
while changes in electron number generate ions.
Atoms with unfilled electron shells tend to gain,
lose, or share electrons with other atoms and
form chemical bonds.
Ionic bonds are electrical attractions between
oppositely-charged ions; covalent bonds share
electrons between atoms; hydrogen bonds are
weak electrical attractions between oppositelycharged regions of molecules.
Chapter 3 - Concepts and Tools for
Studying Microorganisms
 All living microbes must maintain homeostasis.
 Most bacterial species live a communal life in
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 Two types of cellular organization (prokaryotic
and eukaryotic) are established.
 Ehrlich, Fleming, Domagk, & Waksman
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discover antibiotics as disease-curing chemical
agents.
Today, antibiotic resistance, emerging diseases,
and bioterrorism are challenges facing
microbiology.
Microbial ecology and evolution are driving a
new golden age of microbiology.
 Chemical reactions change bonding partners as
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reactants are converted into products.
Water is a polar molecule and the solvent for all
chemical reactions.
pH is a measure of the acidity of a solution and
fluctuations are prevented by buffers.
Organic molecules contain functional groups
that determine molecular behavior.
Carbohydrates consists of monosaccharides
that are used for energy and as building blocks;
disaccharides that have industrial uses and are
part of microbial wall structure; and
polysaccharides that store energy or have
structural roles.
Lipids are hydrophobic compounds used for
energy, membrane structure, or wall structure.
Nucleic acids are used to build DNA, which is
the genetic material in all living organisms and
RNA, which is an intermediate in the expression
and control of genetic information but is also the
genetic material of many viruses.
Proteins are the workhorses of all cells whose
three-dimensional structure determines function.
biofilms; and, as such, can exhibit a
“multicellular” way of life.
Prokaryotic and eukaryotic cells share several
organizational patterns (genetic, compartmental,
and metabolic) and have several structural
distinctions (organelles).
Microorganisms have been classified by shared
characteristics and have a binomial name.
Today, all organisms are assigned to one of
three domains, which are primarily based on
physical, biochemical, serological, and
especially nucleotide sequencing.
Microbes and viruses are very small and
measured in micrometers and nanometers,
respectively.
The light (compound) microscope magnifies
and resolves specimens using visible light;
staining specimens or other optical
configurations provide contrast.
The electron microscope provides detailed
images of cell structure using the transmission
or scanning scope.
Chapter 4 - Prokaryotic Cell Structure and
Function
 The domain Bacteria contains many common
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but diverse groups of bacterial species; the
domain Archaea has some of the most unusual
organisms (extremophiles) in terms of growth
environments.
Bacterial and archaeal species vary in cell shape
and cell arrangements; most exhibit a rod,
spherical, or spiral shape.
Bacterial and archaeal species contain a variety
of cell structures.
 Pili are proteins fibers allowing cells to attach to
surfaces.
 Flagella are protein appendages used for
motility.
 The glycocalyx (capsule or slime layer) is a
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carbohydrate-rich layer to prevent desiccation,
allow attachment, or evade immune system
defenses.
The cell envelope consists of the cell wall,
which maintains cell shape and prevents cell
rupture; and the cell membrane, a typical
phospholipid bilayer that separate environment
from cell interior and regulates transport of
materials into or out of the cell.
The nucleoid is a subcompartment in the
cytoplasm that contains the genetic information
in the form of a circular bacterial chromosome.
Plasmids are small cytoplasmic loops of DNA
that carry nonessential genetic information.
The cytoplasm also contains ribosomes for
protein synthesis and inclusion bodies that store
nutrients; gas vacuoles and magnetosomes may
be present in some species.
The prokaryotic “cytoskeleton” consists of
cytoplasmic proteins that regulate cell division
and help determine cell shape.
Processes such as transcription and translation
can be spatially separated in bacterial and
archaeal cells.
 Pure cultures can be prepared by a pour-plate
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or streak-plate isolation method.
Population growth can be measured directly
(direct microscopic count) or indirectly (most
probable number or standard plate count).
Chapter 6 – Metabolism of Prokaryotic
Cells
 Metabolism consists of two biochemical
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processes (anabolism and catabolism), many of
which require or release energy (endergonic
and exergonic).
Enzymes are protein catalysts that speed up
chemical reactions by lowering the activation
energy of the reactions.
The active site of an enzyme forms an enzymesubstrate complex that weakens or stretches
chemical bonds, weakening the substrate(s).
Metabolic pathways often are regulated by
enzyme function, which is dependent on
temperature, pH, noncompetitive, and
competitive inhibition.
Energy coupling through ATP is used to drive
endergonic reactions.
Chapter 5 - Prokaryotic Growth and
Nutrition
 Some microbes can carry out fermentation if
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Chapter 7 Prokaryotic Genetics
 Bacterial and archaeal chromosomes are located
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 Most bacterial and archaeal cells reproduce
no inorganic final end product is present. The
process allows glycolysis to continue to produce
two ATPs per glucose consumed.
Microbial fermentation pathways vary
depending on the enzyme system they possess.
Some microbes can carry out photosynthesis
through a process similar to green plants.
Microbes demonstrate four metabolic patterns
(autotrophy and heterotrophy) depending on
the energy source (light or chemical) and carbon
source (CO2 or organic compounds) required.
asexually by binary fission; the actual
generation (doubling) time depends on physical
and chemical factors in the environment.
 In microbes, cellular respiration can be
within the nucleoid where the DNA is
supercoiled in a looped domain structure.
Circular plasmids may be present in the
cytoplasm where they replicate independently of
the chromosome.
DNA replication consists of three stages:
initiation at the origin of replication;
elongation of the replication forks
bidirectionally with the synthesis of
complementary polynucleotides by a DNA
polymerase; and termination, which results in
two identical DNA molecules.
The central dogma summarizes the flow of
genetic information; transcription involves the
copying of a DNA template into RNA (tRNA,
rRNA, or mRNA) by an RNA polymerase;
translation is the synthesis of a polypeptide
from an mRNA by ribosomes.
aerobic (+O2) or anaerobic (−O2) process.
 Cellular respiration has three stages; glycolysis
splits glucose into pyruvate, netting two ATPs;
Krebs cycle converts acetyl CoA CO2,
producing two additional ATPs; and electron
transport and chemiosmosis in the prokaryotic
cell membrane generate an additional 34 ATPs
from the electrons donated from glycolysis and
Krebs.
 A bacterial operon consists of regulatory
 A bacterial growth curve goes through four
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phases (lag, log, stationary, and decline).
 A few bacterial species can produce endospores
in response to nutrient limitation.
 Physical factors controlling cell growth include
temperature, oxygen, pH, and osmotic pressure.
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found in culture media (solid agar and nutrient
broth), which can consist of a complex medium
or synthetic medium.
Selective, differential, and enriched media can
be used, respectively, to select for or
differentiate between species, or to grow
fastidious microbes.
Some 99 percent of all microbes cannot be
grown in a known culture medium; they
represent viable but not culturable (VBNC)
species.
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 Chemical factors are based on the nutrients
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 Microbes can use other organic molecules for
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energy production including lipids and proteins.
Many microbes employ anaerobic respiration,
which uses the same stages as aerobic
respiration, except an inorganic final electron
acceptor other than O2 is used and a different
final end product than water is formed.
segments (promoter and operator) and
functionally-related structural genes. A
separate regulatory gene may produce a
repressor protein that can exert negative
control over an operon.
Mutations are permanent changes in the DNA
sequence caused by unrepaired replication
errors, physical or chemical mutagens, or
transposable genetic elements (transposons).
Auxotrophs result from a nutritional mutation
in a prototroph (wild-type) cell.
Mutations can be detected by negative or
positive selection plating techniques.
The Ames test uses auxotrophic bacteria to
identify a chemical that can act as a mutagen
and carcinogen in humans.
Chapter 8 - Gene Transfer, Genetic
Engineering, and Genomics
 Genes are passed between generations through
vertical gene transfer or transferred to the
same generation by horizontal gene transfer.
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 Transformation transfers a DNA segment from
a dead donor cell to a competent live recipient.
 Conjugation through physical contact transfers
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an F plasmid or part of a chromosome (Hfr)
from live donor to live recipient.
Transduction involves a bacterial virus
transferring a donor DNA segment from dead
donor to live recipient.
Genetic engineering involves an alteration to
the genetic material in a microbe using a
recombinant plasmid so the genes expressed
produce a novel product or trait.
diphtheriae and Bordetella pertussis that
inhibit protein synthesis and destroy the
ciliated epithelium, respectively.
 Bacterial meningitis is caused by several
bacterial species, including Neisseria
meningitidis, which infect the nasopharynx
and rapidly spread to the meninges.
Several bacterial diseases affect the lower
respiratory tract:
 Tuberculosis, caused by Mycobacterium
tuberculosis, can result in a latent infection
that can turn deadly in the lungs or spread to
other parts of the body (miliary TB).
Pneumonia can take several forms depending on
the infecting bacterial species:
 Pneumococcal pneumonia is community
acquired by infection with Streptococcus
pneumoniae.
 Atypical pneumonia is caused primarily by
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 Shigellosis (Shigella sonnei).
 Cholera (Vibrio cholerae).
 E. coli diarrheas (ETEC, EPEC, EHEC).
 Gastric ulcer disease (Helicobacter pylori)
 Campylobacteriosis (Campylobacter jejuni)
 Listeriosis (Listeria monocytogenes)
Chapter 11 - Soilborne and
Arthropodborne Bacterial Diseases
 Anthrax, tetanus, and gas gangrene are
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intoxications from the soilborne bacteria
Bacillus anthracis, Clostridium tetani, and C.
perfringens, respectively.
Leptospirosis is spread from other animals to
humans, often through water contaminated with
Leptospira interrogans.
Several bacterial diseases are arthropodborne:
 Plague is spread by rodents and their fleas
infected with Yersinia pestis.
 Tularemia is caused by Francisella
tularensis.
 Lyme disease and relapsing fever are tickborne diseases involving Borrelia species.
Mycoplasma pneumoniae (walking
pneumonia) or Legionella pneumophila
(Legionnaires’ disease).
Q fever is caused by Coxiella burnetii.
Psittacosis and chlamydial pneumonia result
from infections by Chlamydia psittaci and C.
 Other arthropodborne diseases include Rocky
Mountain spotted fever, epidemic and endemic
typhus that are caused by rickettsial bacteria;
ehrlichiosis is transmitted by ticks infected with
Ehrlichia species.
Chapter 12 - Sexually Transmitted,
Contact, and Miscellaneous Bacterial
Diseases
pneumoniae, respectively.
 Biotechnology represents the process of
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producing commercial or industrial applications
using genetic engineering.
Microbial genomics includes sequencing
microbial genomes to understand an organism’s
genetic organization and function (functional
genomics) with the intent to use the information
for scientific, medical, or industrial purposes.
Comparative genomics compares genomes of
similar or dissimilar species to study
evolutionary relationships of the “tree of life.”
Chapter 9 - Airborne Bacterial Diseases
 Several bacterial diseases affect the upper
respiratory tract:
 Strep throat, scarlet fever, and rheumatic
fever are caused by Group A streptococci.
 Diphtheria and pertussis involve bacterial
toxins produced by Corynebacterium
Chapter 10 - Foodborne and Waterborne
Bacterial Diseases
 Foodborne and waterborne infections can be the
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result of intoxications or infections.
Water and food become contaminated through
animal slaughter, exposure to animal mature,
human sewage, or fecal matter. They can occur
in many locations.
Intoxications include botulism (Clostridium
botulinum) and food poisoning
(Staphylococcus aureus or Clostridium
perfringens).
Foodborne and waterborne infections produce
several diseases, including gastroenteritis. The
major ones are:
 Typhoid fever (Salmonella enterica serotype
Typhi).
 Salmonellosis (S. enterica serotype Enteritidis
and Typhimurium).
 Syphilis, gonorrhea, and chlamydial urethritis
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are sexually transmitted diseases (STDs) caused,
respectively, by Treponema pallidum, Neisseria
gonorrhoeae, and Chlamydia trachomatis.
Chancroid, Ureaplasma urethritis,
lymphogranuloma venereum, and bacterial
vaginosis are additional STDs.
Contact infections include:
 Leprosy (Hansen disease), which is a chronic
and systemic infection caused by
Mycobacterium leprae.
 Abscesses, boils, impetigo, and toxic shock
syndrome resulting from infection with
Staphylococcus aureus.
 Trachoma, caused by Chlamydia trachomatis,
is the world’s leading cause of preventable
blindness; bacterial conjunctivitis (pinkeye)
caused by Haemophilus aegyptius (influenzae
type III).
Endogenous bacterial diseases include:
 Peritonitis caused by Bacteroides fragilis;
Pseudomembranous colitis caused by
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Clostridium difficile; Actinomycosis and
Nocardiosis is caused by Actinomyces israelii
and Nocardia asteroides, respectively.
 Pasteurellosis, cat-scratch disease, and ratbite fever are diseases caused by bites from
infected cats, dogs, and some wild rodents.
Diseases of the oral cavity include dental caries
 Bacteriophages replicate within the host cell
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and periodontal disease.
Urinary tract infections usually develop into
urethritis, although bladder (cystitis) and kidney
infections (pyelonephritis) can also occur due to
a range of bacterial infections.
Nosocomial infections or hospital-acquired
infections are a major health care issue. Many
opportunistic bacteria can cause infections
especially in immunocompromised patients.
 Cytological investigations and cytopathic effects
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identified as the source of some infectious
diseases in humans.
Viruses consist of a genome packaged in a
protein coat (capsid); some viruses have an
envelope surrounding the nucleocapsid and
spikes extending from the surface.
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 AIDS are caused by the human
immunodeficiency virus type 1 (HIV-1).
 HIV replication is dependent on a reverse
cultures and enumerated by plaque formation.
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association and can contain oncogenes that
trigger uncontrolled cell growth.
Several emerging viruses have appeared in
human populations as the result of viral
recombination and mutation.
Three hypotheses (regressive, cellular, and
independent) have been suggested to explain the
origins of viruses
Viroids are infectious RNA particles that affect
some plant species; prions are infectious
proteins that can cause neurologic degenerative
diseases in many animals, including humans.
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Chapter 14 - Viral Infections of the
Respiratory Tract and Skin
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 Several viruses affect the human upper
 Viruses are placed into one of three shapes
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(helical, icosahedral, or complex).
Viruses exhibit a host range and, for animal
viruses, a tissue tropism.
Viruses can be classified into families based on
nucleic acid type [DNA viruses (double or
single stranded) and RNA viruses (double or
single stranded); RNA viruses also be can be
separated by being + or − stranded.
All viruses go through 5 phases of replication
(attachment, penetration, biosynthesis,
maturation, and release).
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respiratory tract. The diseases include:
 Influenza, caused by influenza viruses A and
B that change genetically every year as a
result of antigenic drift and antigenic shift.
 Common colds, often caused by rhinoviruses
and adenoviruses.
Many viruses affect the human lower respiratory
tract, responsible for disease that include:
 Viral pneumonia (respiratory syncytial virus),
acute respiratory infections (parainfluenza
viruses), and severe acute respiratory
syndrome (SARS coronaviruses).
Herpesviruses cause several infections and
disease of the skin, including:
 Cold sores and genital herpes (HSV-1 and 2), chickenpox and shingles (varicella-zoster
virus), roseola (HHV-6), and Kaposi sarcoma
(paramyxoviruses), rubella (togavirus), fifth
disease (parvovirus), and common and genital
warts (papillomaviruses).
The poxviruses are most noted for causing
smallpox, a viral disease that has been
eradicated through vaccination from the world.
Chapter 15 - Viral Infections of the Blood,
Lymphatic, Gastrointestinal, and Nervous
Systems
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 About 20 percent of human tumors have a viral
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(HHV-8).
 Other skin diseases include measles and mumps
can be used to detect specific viruses.
 Many human viruses can be cultivated in cell
Chapter 13 - Viruses and Virus-Like Agents
 In the early part of the 20th century viruses were
cytoplasm; new virulent phage burst out of the
cell (lytic cycle) while temperate phage may
integrate their DNA into the host chromosome
as a prophage (lysogenic cycle).
In animals, herpesviruses replicate within both
the nucleus and cytoplasm of the host cell; RNA
viruses replicate in the cytoplasm; and
retroviruses reverse transcribe RNA into DNA.
Some DNA viruses and retroviruses integrate
their DNA into the host cell chromosome
(provirus) and remain in a state of latency.
Antiviral drugs can treat a few human viral
diseases, such as cold sores and HIV infections.
Interferon is a naturally-made human protein
that puts cells in an antiviral state.
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transcriptase within its primary target cells,
CD4+ T lymphocytes.
HIV disease is the early stages (I and II) leading
to AIDS (stage III).
AIDS patients usually die from an
opportunistic infection.
HIV is usually transmitted through some form
of blood transfer or sexual intercourse with an
infected individual.
Highly active antiretroviral therapy
(HAART) is one antiviral drug combination
used to slow down the infection process.
Infectious mononucleosis and cytomegalovirus
disease are blood-borne diseases caused by
herpesviruses.
Hepatitis B, C, D, and G are bloodborne viral
diseases affecting the liver.
Yellow fever and Dengue fever represent two
viral hemorrhagic fevers caused by flaviviruses.
Hantavirus disease, sandfly fever, and Rift
Valley fever are bunyavirus-caused hemorrhagic
fevers.
Ebola and Marburg hemorrhagic fevers are
caused by filoviruses that produce hemorrhagic
lesions.
Lassa fever is a hemorrhagic fever transmitted
by rodents infected with this arenavirus.
Hepatitis A and E are liver infections caused
hepatitis viruses transmitted via the
gastrointestinal tract.
Viral gastroenteritis represents a common illness
often due to viral gastrointestinal infections
caused by rotaviruses, noroviruses, or
enteroviruses.
Rabies is a nervous system disease caused by
infection of the rabies virus; once symptoms
appear the disease is almost always fatal.
Polio (poliomyelitis) is a potentially severe
paralytic disease of the nervous system caused
by infection with the polio virus.
Several types of encephalitis are caused by
infections from arthropods infected with
togaviruses, bunyaviruses, or flaviviruses (West
Nile fever/encephalitis).
Chapter 16 - Eukaryotic Microorganisms:
The Fungi
 Fungi, including the molds and yeasts, compose
the kingdom Fungi within the domain Eukarya.
 Molds grow as filaments called hyphae that
 Trypanosomiasis can be transmitted
may be septate or nonseptate and form thick
masses called a mycelium.
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 Pneumocystis pneumonia, caused by
 Fungi are heterotrophic, most representing
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saprobes (decomposers).
 Like most organisms, fungal growth is
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influenced by oxygen, temperature, and pH.
Symbiotic (mutualistic) relationships occur with
plants, as mycorrhizae or endophytes.
Reproduction involves formation of asexual and
sexual spores that are often carried in the air.
Sexual reproduction involves opposite mating
types that forma fusion cell called a
heterokaryon.
The fungal taxonomic groups are usually
assigned according to the form of sexual
reproduction observed; the Zygomycota,
Ascomycota, and Basidiomycota have unique
sexual reproductive structures, while the
mitosporic fungi (not a taxonomic group) are
reassigned if a sexual stage is discovered.
The yeasts reproduce by budding and play
important roles in industry and research.
Several fungi can cause diseases of the skin:
 Dermatophytosis (e.g., ringworm and
athlete’s foot) is a relatively common
infection caused by a variety of fungi.
 Candidiasis, caused by Candida albicans, is
more commonly called vaginitis or thrush.
 Sporotrichosis forms lesions under the skin
after an infection with Sporothrix schenkii.
Fungal spores can infect the lower respiratory
tract and cause several diseases:
 Cryptococcosis, caused by Cryptococcus
neoformans, affects the lungs and meninges.
 Histoplasmosis and Blastomycosis are
potentially systemic diseases caused,
respectively, by Histoplasma capsulatum and
Blastomyces dermatitidis.
 Coccidioidomycosis can be a disseminated
and life-threatening disease following
infection by Coccidioides immitis spores.
Pneumocystis jiroveci, is an opportunistic
infection often found in AIDS patients.
Other fungal mycoses include aspergillosis and
a mycotoxin intoxication called ergotism.
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Chapter 17 - Eukaryotic Microorganisms:
The Parasites
Trypanosoma brucei-infected tsetse flies
(human African sleeping sickness) or American
trypanosomiasis (Chagas disease) involving T.
cruzi-infected reduvid bugs.
Babesiosis and Toxoplasmosis are additional
bloodborne protozoal parastic diseases caused
by Babesia macroti and Toxoplasma gondii,
respectively.
Primary amoebic meningoencephalitis is a rare
nervoius system disease caused by Naegleria
fowleri.
The helminthic parasites are multicellular
animals and include the flatworms and
roundworms.
Flatworm-caused diseases require definitive and
intermediate hosts and include: schistosomiasis
(Schistosoma species); lung and liver fluke
diseases; and tapeworm diseases.
 The protists are a very heterogeneous group in
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the domain Eukarya, which includes the green
algae and the protozoa.
The protozoa include the parabasalids,
diplomonads, and kinetoplastids that possess
flagella; the amoebozoans that exhibit
amoeboid motion; the ciliates that possess
cilia; and the apicomplexans that are mot
motile in the adult form.
Many protozoan parasites have trophozoite and
cyst stages and infection involves definitive and
intermediate hosts.
Some protozoal diseases affect the skin, or the
digestive or urinary tracts:
 Leishmaniasis is a vector-borne (sandfly)
disease causing a cutaneous (Leishmania
major) or visceral disease (L. donovani).
 Amoebiasis (Entamoeba histolytica),
giardiasis (Giardia intestinalis),
cryptosporidiosis (Cryptosporidium parvum
and C. hominis), and cyclosporiasis
(Cyclospora cayetanensis) are diseases of the
digestive tract.
 Trichomoniasis is a relatively common
protozoal parasitic disease of the urinary tract
caused by Trichomonas vaginalis.
Malaria is caused by four species of
Plasmodium.
The malarial parasite requires both definitve
(mosquito) and intermediate (human) hosts.
 Roundworm diseases do not require two hosts
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and include; pinworm disease (Enterobius
vermicularis) and trichinellosis (Trichinella
spiralis); soilborne diseases (ascariasis, and
hookworm disease).
Helminthic parasitic disease of the lymphatic
system (filariasis) is caused by the roundworm
Wuchereria bancrofti.
Chapter - 18 Infection and Disease
 Infection, the competition between host and
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microbe or virus, precedes disease, which refers
to a change from the healthy state.
The human microbiota helps protect the host
from pathogen colonization, as most microbiota
represent symbiotic relationships that are
examples of mutualism or commensalism.
Pathogenicity and virulence are important
factors in the establishment of a disease,
whether resulting from an endogenous or
exogenous infection.
Many opportunistic infections are secondary
infections resulting from a primary infection.
Microbes or viruses can be disseminated
through the blood.
A disease progresses through a series of five
stages characterized by specific signs and
symptoms.
To become ill, the host must receive a certain
infectious dose (characteristic of the pathogen)
through some portal of entry.
 Complement, which enhances the processes
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 Immature T cells mature into T helper (TH)
of phagocytosis and inflammation while
eliminating some pathogens.
Pathogen-associated molecular patterns
(PAMPS) can be recognized toll-like receptors
present on macrophages, dendritic cells, and
endothelial cells.
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cells; TH1 target infected macrophages while
TH2 help activate epitope-bound B cells.
Cytotoxic T cells, activated by dendritic cells
or through an interaction of CD8 T cells with
an APC, target and destroy infected cells.
Chapter 21 - Immunity and Serology
 Infection and disease is the result of a pathogen
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overcoming host barriers, which may require the
possession of virulence factors.
Virulence factors include structural factors,
enzymes, and toxins.
Bacterial toxins include the exotoxins and
endotoxins.
Disease can be communicable or
noncommunicable and transmitted by direct or
indirect methods.
Those areas where a microbe “lives” and
multiplies are called reservoirs.
Disease spread can have endemic, epidemic, or
pandemic consequences.
Nosocomial infections often results from a
chain of transmission that can be broken using
universal precautions.
The emergence or resurgence of disease can be
the result of several factors.
Chapter - 20 Resistance and the Immune
System: Acquired Immunity
 Acquired immunity requires the attributes of
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Chapter 19 - Resistance and the Immune
System: Innate Immunity
specificity, tolerance of “self,” minimal “self”
damage, and immunological memory.
Acquired immunity has two responses: a
humoral response to pathogens in fluids and a
cell mediated response to pathogens infecting
cells.
Lymphocyte activation involves only those B
and T cells recognizing an epitope or antigen
peptide, respectively; the result is activated
effector cells (B and T cells).
All immune defensive cells arise from
hematopoietic stem cells in the bone marrow.
The humoral response is mediated by activated
B cells that mature into memory B cells and
plasma cells.
 Antibodies are immunoglobulins; proteins
consisting of four polypeptide chains, two
identical heavy (H) chains and two identical
light (L) chains in the monomer state.
 Active immunity involves the production of T
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 Leukocytes, especially neutrophils,
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macrophages, dendritic cells, and
lymphocytes are blood cells important to innate
and acquired immunity.
The lymphatic system contains primary and
secondary tissues important toward fighting
infection and disease.
Individuals are born with innate immunity
while acquired immunity is a form of specific
resistance gained during an individual’s life.
The innate first lines of defense include
mechanical, chemical, and microbiological
barriers.
The innate second lines of defense include:
 Phagocytosis by phagocytes, which engulf
and clear microbes from the body.
 Epitopes bind at the H-L antigen binding
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 Inflammation that heightens the immune
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defenses and fever that can slow down
pathogens while speeding up immune
defenses.
Natural killer (NK) cells can eliminate
virus-infected cells and cancer cells.
and B cells, and antibodies, as a result of
exposure to a pathogen or receiving a vaccine.
Passive immunity involves receiving antibodies
from another source.
A vaccine is composed of a pathogen that has
been treated in some way:
 Whole agent vaccines represent attenuated,
inactivated, or toxoid vaccines.
 Other vaccines include subunit, conjugate,
DNA, or recombinant vector vaccines.
Passive immunity can be acquired through IgG
passage to fetus (naturally acquired) or
injection of antibody-rich sera (artificially
acquired).
Herd immunity protects a population by
maintaining high vaccination levels within the
population (herd).
Although very rare, some vaccines can have
dangerous side effects.
Serological reactions involve antigen-antibody
interactions.
 Neutralization involves the inactivation of an
exotoxin or virus.
 Precipitation forms visible aggregates often
involving immunodiffusion or
immunoelectrophoresis.
sites and phagocytes may be able to bind to
the Fc fragment.
 There are five classes of immunoglobulins;
IgG, IgM, and IgA are the “disease fighters”
while IgE plays a role in allergies and IgD is
a receptor on B cells.
 A primary antibody response occurs to the
first exposure to a pathogen (antigen) while a
secondary antibody response is a much
faster response mediated by memory cells to
an ensuing exposure to the same antigen.
 The diversity in antibody populations is based
on a somatic recombination process.
 Pathogen (antigen) clearance is dependent on
phagocytosis by macrophages.
The cell mediated response is controlled by
activated T cells.
 T-cell receptors and coreceptors recognize
and bind to major histocompatibility
complex (MHC) proteins on antigenpresenting cells (APC; MHC-II) or infected
target cells (MHC-I).
 Naive T cells recognize peptide fragments
presented on antigen-presenting cells
(macrophages or dendritic cells).
 Interleukin secretion generates a clone of
immature T cells and T memory cells.
 Agglutination involves the clumping of cells
or objects (antigens) by antibodies.
 Complement fixation involves the hemolysis
of red blood cells.
 Labeling methods detect antigen-antibody
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binding by:
 Fluorescent antibody, radioactive antibody
(radioimmunoassay), or enzyme-linked
antibody (ELISA).
Monoclonal antibodies are laboratorydeveloped immunoglobulins that recognize only
one epitope on a cell or other antigen.
Gene probes are single-stranded DNA
segments that recognize pathogen DNA.
Chapter 22 - Immune Disorders
 A hypersensitivity results from an immediate
or delayed exposure to an antigen or allergen.
 Salting and low temperatures are additional
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control methods.
Chemical methods of control involve the use of
antiseptics on living surfaces and disinfectants
on inanimate objects.
 Antifungal drugs are fewer in number and
 Type I hypersensitivity involves IgE antibodies
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and degranulation of cell mediators from
basophils and mast cells.
 Systemic anaphylaxis can cause a lifethreatening system-wide release of mediators
while atopic disorders are localized and
typical of common allergies.
 Asthma can be a dangerous hypersensitivity
that constricts the airways.
Allergy therapies include desensitization,
blocking antibodies, and the use of
antihistamines or other drugs.
Type II cytotoxic hypersensitivity results from
IgG interactions with cell surfaces.
Type III immune complex hypersensitivity
occurs when antibodies combine with antigens
and form aggregates in blood vessels.
Type IV cellular hypersensitivity is an
exaggerated delayed cell-mediated immune
response by T cells.
Autoimmune disorders can occur when
acquired immunity loses self-tolerance.
Acquired immunity is responsible for tissue or
organ transplant rejection.
Immunodeficiency disorders occur when
acquired or humoral immunity loses the ability
to respond to non-self antigens.
Chapter 23 - Physical and Chemical
Control of Microorganisms
 The effectiveness of chemical control can be
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Chapter 24 - Antimicrobial Drugs
 Antimicrobial drugs are a group of
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 Sterilization involves the removal of all living
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microbes, spores, and viruses from an object or
area while sanitization reduces the numbers to a
level deemed safe.
There are several physical methods of control:
 Dry heat (including incineration) can kill
microbes while moist heat (such as
pasteurization) can kill pathogens; other
methods can control microbial levels and be
measured through the thermal death time or
thermal death point.
 Filtration is a mechanical method to
removed microbes from air or water.
 Ultraviolet light is bactericidal while
ionizing radiations are microbicidal and can
be used to preserve foods.
measured by the phenol coefficient or the inuse test.
Chemical control methods include:
 Halogens, such as chlorine and iodine,
oxidize proteins.
 Phenolic derivatives denature proteins.
 Heavy metals, such as mercury and silver,
interfere with microbial metabolism.
 Alcohols denature proteins and disrupt
membranes.
 Detergents, such as the quats, react with cell
membranes.
 Hydrogen peroxide can damage cellular
components.
 Aldehydes, and ethylene oxide and chlorine
dioxide gases, can sterilize.
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chemotherapeutic agents.
The age of chemotherapy started with Ehrlich
and Domagk, but the use of naturally produced
chemicals (antibiotics) was most advanced by
Fleming, Waksman, Florey, and Chain.
The effectiveness of antibiotics depends on their
selective toxicity and antimicrobial drug
spectrum.
The synthetic antibacterial agents include the
sulfonamides, isoniazid, ethambutol, and the
quinolones.
Antibiotics with a beta-lactam nucleus inhibit
cell wall synthesis and include the penicillins,
cephalosporins, monobactams, and
carbapenems.
Other bacterially-produced antibiotics included:
 Vancomycin (cell wall inhibitor).
 Bacitracin and polymyxins (affect cell
membranes).
 Aminoglycosides, chloramphenicol,
tetracyclines, macrolides, clindamycin, the
streptogramins, and oxazolidinones
(translation inhibitors).
 Rifampin (transcription inhibitor) and the
quinolones (DNA replication).
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include: polyenes and imidazoles (disrupt cell
membranes); echinocandins (inhibit cell wall
synthesis); flucytosine (inhibits nucleic acid
synthesis); and griseofulvin (mitosis inhibitor).
Antiprotozoal and antihelminthic drugs attempt
to eradicate the parasite.
Antiprotozoal agents: Aminoquinolines
(antimalarial); sulfonamides and heavy metals
(metabolic inhibition); and nitroimidazoles
(inhibit DNA synthesis).
Antihelminthic agents: Praziquantel (interferes
with membrane permeability); mebendazole
(inhibits glucose uptake); and the avermectins
(affect the nervous system).
The effectiveness of antibiotics can be tested
with susceptibility assays, including the tube
dilution method and the agar disk diffusion
method.
 Resistance to antibiotics can be the result of
mutations or lateral gene transfer conferring an
altered metabolic pathway, antibiotic
inhibition, reduced permeability/active
export, or target alteration.
Chapter 25 - Microbiology of Foods
 Food spoilage can be the result when foods are
altered from their expected form.
 The chemical and physical properties of food
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(water, pH, oxygen, temperature, physical
structure, and chemical composition) determine
what pathogen may grow on it.
Spoilage can result from microbial metabolism,
which often produces foul-smelling products.
Meats and fish can become contaminated
through the handling and processing procedures.
Poultry and eggs can be contaminated from
human contamination or by penetration of
bacterial species.
Breads and bakery products can spoil from
bacterial or fungal growth.
Grains can be contaminated by aflatoxin and
ergot produced specific groups of fungi.
Milk and diary products can spoil or curdle due
to the presence of contaminating microbes that
produce acids or enzymes.
Foods can be preserved with heat (through
chemical sterilization or pasteurization) or low
temperatures (refrigeration and freezing).
 Of the three types of water pollution, only
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biological pollution is the result of human
waste introducing enteric microorganisms.
The measurement of polluted water is
determined by the biological oxygen demand.
Many human intestinal and skin diseases
(bacterial, protozoal, viral) can be transmitted
through water.
Water purification is a three step process
involving sedimentation of large particulate
matter, filtration to trap microorganisms, and
chlorination to kill remaining microorganisms.
In sewage treatment, the primary treatment
removes grit and large insoluble waste;
secondary treatment degrades the biological
content of the sewage; and the tertiary
treatment purifies any water remaining after
solid sludge separation.
Chapter 27 - Industrial Microbiology and
Biotechnology
 Industrial fermentation can involve aerobic or
anaerobic organisms in a bioreactor.
 Useful organic compounds can be produced by
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 Preservation of foods can involve freeze-drying
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(lyophilization) or the use of osmotic pressure
to dehydrate foods.
Chemical preservatives can inhibit the growth
of microorganisms in food.
Irradiated foods (UV and gamma rays) can
reduce microbial surface contamination.
Foodborne diseases involve food infections
(ingestion of living microbes) or food
intoxications (ingestion of microbial toxin).
The Hazard Analysis and Critical Control
Point (HACCP) is a food safety system
designed to identify potential points of
microbial contamination.
Many foods (e.g., sauerkraut, pickles, vinegar,
and soy sauce) are the result of a microbial
fermentation process.
Milk products (e.g., buttermilk, yogurt, and
cheeses) are the result of a fermentation process.
Chapter 26 - Environmental Microbiology
 Surface water, unlike groundwater, is likely to
become contaminated.
 The microbial population in unpolluted and
polluted water differs, the later being potentially
subject to coliform bacteria and algal blooms.
 Biofilms are complex organizations of
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microorganisms in soil, water, inanimate
objects, or the human body.
The biological analysis of water involves
techniques (membrane filter technique,
standard plate count, or most probable
number) to detect organisms indicating fecal
contamination.
The carbon cycle involves the exchange of
carbon between living organisms, including
microorganisms as decomposers, and the
environment.
The sulfur cycle is dependent on anaerobic
organisms to convert sulfate to hydrogen sulfide
and vice-versa.
The nitrogen cycle involves a series of
microbial processes by which nitrogen is
converted from a gas in the atmosphere to
nitrogen-containing substances in soil and then
reconverting nitrates to nitrogen gas.
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microorganisms from primary and secondary
metabolites.
Microbial enzymes are another product of
biotechnology.
Alcoholic beverages (Beer, wine, and distilled
spirits) are the result of controlled fermentation
processes.
Other microbial products of biotechnology
include antibiotics and insecticides.
The biotechnological industrialization of yeast
growth and mushroom farming has generated
food or food supplement sources.
Bioremediation uses natural or engineered
bacterial species to break down toxic waste,
toxic plastics, and radioactive materials.
Industrial genetic engineering using plasmid
technology will provide limitless possibilities
for startling future developments in medicine,
agriculture, pharmaceutical, and chemical
industries.