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microbiology exam 13, 14, 15

STUDY
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chemotherapy
use of a chemical substance to treat different aspects of disease
Chemotherapeutic agent
any chemical substances used in medical practice to treat disease (a.k.a drugs)
antimicrobial agent
agent used to treat diseases caused by microbes
antibiotics
chemical substance produced by microorganisms; have capacity to inhibit growth of bacteria; used in dilute solutions or it can be toxic
synthetic drugs
drugs made by man in a lab
ancient remedies
molded bread on open wounds, plants for external treatment, Karaway seed used in India to treat cancer
Ehrlich
first to use chemical to treat the whole body from disease; coined the term chemotherapy; treated syphilis
Domagk
discovered that prontosil dye prohibits the growth of gram + cells
Flemming
discovered penicillin; noticed that mold from a "spoiled" experiment inhibited the growth of germs; he made a broth that could be effective on wounds
Penicillin
best against Gram + bacteria
selective toxicity
harms the microbes without significantly harming the host
spectrum of activity
the range of microbes that the antibiotic can fight against; an antimicrobial agent refers to the variety of microorganisms sensitive to the agent.
narrow spectrum
those that are effective against only a small number of microorganisms or a single taxonomic group (agents attack only a few different organisms)
broad spectrum
agents that effective against a great number of microorganisms from a wide range of taxonomic groups, including Gram-positive and Gram-negative bacteria; tetracylcines (agents attack many different organims)
5 Drug Mechanisms of Action
-Inhibition of Cell Wall Synthesis
-Disruption of Cell Membrane Function
-Inhibition of Protein Synthesis
-Inhibition of Nucleic Acid Synthesis
-Action of Antimetabolites
inhibition of cell wall synthesis
allow the membrane of the affected microbe to rupture and release the cell contents.

-does not hurt animal cells because they lack a cell wall; best for gram +; i.e. penicillin
disruption of cell membrane function
dissolve the membrane or interfere with the movement of substances into or out of cells.

-act as detergents that distort the lipid cell membrane; best for gram -; i.e. polymixins
inhibition of protein synthesis
prevent growth of microbes by disrupting ribosomes or otherwise interfering with the process of translation.

-inhibits protein synthesis so they cannot produce proteins; i.e. streptomycin
inhibition of nucleic acid synthesis
interfere with synthesis of RNA (transcription) or DNA (replication) or disrupt the information these molecules contain.

-binds to RNA polymerase to stop RNA synthesis by stopping nucleic acid formation
antimetabolites
substances that affect the utilization of metabolites and therefore prevent a cell from carrying out necessary metabolic reactions.
FUNCTION:
-affect normal metabolites by competitively inhibiting microbial enzymes
-or by being erroneously incorporated into important molecules such as nuclei acids
Kinds of Side Effects
side effects antimicrobial agents on the host include toxicity, allergy, and disruption of normal microflora.

-allergic reactions to antimicrobial agents occur when the body reacts to the agent as a foreign substance.

-many antimicrobial agents attack not only the infectious organism but also normal microflora.

-superinfections with new pathogens can occur when the defensive capacity of normal microbiota is destroyed.
sulfanilamide
mimics PABA to inhibit normal cell functions
toxicity
the chemicals could be toxic to the human system
allergy
rashes, itching, anaphylactic shock
anaphylactic shock
body can't regulate itself
disruption of Microflora
kills the good bacteria in the body making it more susceptible to infection
resistance drugs
acquire via genetic change or non-genetic mechanisms or evasion if bacteria live in areas where ab can't reach
natural selection
genetic changes leading to abnormal resistance; occurs spontaneously
chromosomal
mutation in drug receptor
plasmid borne
R plasmid via conjugation, transduction, and transformation
antibiotic resistance
ability to grow in the presence of antibiotics
first/second/third line drugs
how many times its been recreated because of resistance
cross resistance
resistance to 2 or more drugs
pathogen
a parasite capable of causing disease
host
an organism that harbors another organism
symbiosis
"living together"
mutualism
both organisms benefit
commensalism
one organism benefits and the other neither benefits nor is harmed; microbial competition
parasitism
one organism benefits and the other is harmed; antagonism
contamination
microorganisms are present
infection
pathogens invade the body
infestation
presence of worms or arthropods in or on the body
disease
pathogens or other factors disturb the state of health such that the body cannot perform its normal functions
pathogenicity
the ability of the organism to cause disease; certain strains/species can be higher in this ability;bigger picture then virulence
virulence
disease causing power of a pathogen (specific factors)
avirulence
loss of its disease causing power
attenuation
virulence has slightly changed
in vivo
animal passage
in vitro
in culture
en utero
getting microorganisms in our body in birth through the birth canal
teratogenic
harmful to baby
immunocompromised
failure of the host's natural defenses
multiplicity of infection
the more pathogens in system the higher risk for disease
resident microflora
not usually found on our internal organs or deep tissue or blood, or brain, or urine
transient microflora
present temporarily and under certain conditions
opportunists
resident or transient microflora that can cause disease under certain conditions or certain locations of the body
infectious agents
cause infectious diseases; i.e. bacteria, viruses, fungi, protists, and helminths
noninfectious agents
inherited, degenital (born with it), immunological, mental, nutritional deficient
communicable
contagious infectious disease that can be spread from one host to another
non communicable
can't be spread form host to host and may be acquired in soil, water, or contaminated foods
endotoxin
part of the cell wall of Gram - bacteria and are released when cells divide or are killed; highly inflammatory
exotoxin
produced by and released from bacteria; proteins secreted by Gram + (mostly); powerful; i.e. hemolysins
productive infection
leads to the release of a virus progeny
abortive infection
does not produce infectious progeny
latent disease
a disease characterized by periods of inactivity either before symptoms appear or between attacks
persistent infection
the continued production of the infectious parasite within the host over many months or years
sign
observable effect of a disease; swelling, fever, rash
symptom
an effect of a disease felt by the infected person; pain, nausea
syndrome
a group of signs and symptoms that occur together
sequelae
abnormal condition that is a side effect of a disease; pox mark-chicken pox, paralysis-polio
acute disease
a disease that develops rapidly and runs its course quickly
chronic disease
a disease that develops more slowly, is usually less severe, and persists for a long indeterminate period
subacute disease
a disease that is intermediate between an acute and a chronic disease
local infection
an infection confined to a specific area of the body
focal infection
an infection confined to a specific area from which pathogens can spread to other areas
systemic infection
an infection that affects the entire body (generalized infection)
septicemia
an infection caused by rapid multiplication of pathogens in the blood; blood poisoning
bacteremia
an infection in which bacteria are transported in the blood but do not multiply in transit; spreading of bacteria infection
viremia
an infection in which viruses are transported in the blood but do not multiply in transit; spreading of virus infection
primary infection
an initial infection in a previously healthy person
superinfection
a secondary infection from the removal of normal microbiota, allowing colonization by pathogenic, and often antibiotic resistant, microbes
mixed infection
an infection caused by several species of organisms present at the same time
inapparent infection
an infection that fails to produce symptoms, either because too few organisms are present or because host defenses effectively combat the pathogens
incubation period
the time between infection and the appearance of signs and symptoms of a disease; most severe signs and symptoms
prodromal phase
the stage during which pathogens begin to invade tissues; it is marked by early nonspecific symptoms
invasive phase
the period during which the individual experiences the typical signs and symptoms of the disease
acme
during the illness phase of the disease process, the time of most intense signs and symptoms
decline phase
the stage during which host defenses overcome pathogens; signs and symptoms subside during this phase, and secondary infections may occur
convalescence period
the stage during which tissue damage is repaired and the patient regains strength; recovering individuals may still transmit pathogens to others
disease
deviation or interruption of the normal structure of a living organism, accompanied by a set of signs; infectious and non; parasite and disease NOT interchangeable
epidemiology
study of factors and mechanisms in the spread of disease in a population
etiology
the cause of disease
prevalence
number of infected/ total number in population; usually higher number
incidence
number of new infections in some time period/ number of hosts in population
intensity
number of parasites in one host
transmission
move from one infected individual to another (possibly via a vector or direct contact: skin, ingest, transfusion, transplant)
epidemic
affecting a significantly large number of people at the same time
endemic
expected or normal incidence indigenous to a geographical area or population
pandemic
epidemic over a wide geographic area and affecting a large proportion of the population
sporadic
occasional cases occur in irregular intervals at unlikely locations
morbidity
the number of cases compared to the total population
mortality
number of deaths compared to the total population
common source outbreak
spread by a contaminated substance
propagated epidemic
spread by person to person contamination
descriptive
concerned with the physical aspects of an existing disease and disease spread
index case
first case of the disease
analytical
looking and focusing on finding the cause-effect relationship on the occurrence of diseases in a population
experimental
tests a hypothesis often about the value of a particular treatment
reservoirs of infection
sites where organisms can persist and maintain there ability to infect; could be animal or human
portals of entry
sites where microorganisms enter body; open orifice:nose, ears, mouth, etc
portals of exit
sites where organisms leave the body
zoonoses
diseases passed from animal to human
fomites
an object that carries infectious diseases
vehicles
non living carriers
vectors
living object that carries disease; fleas, ticks, mosquitos
horizontal transfer
spreading from one human to another
vertical transfer
passed from mother to child
acute carriers
individuals within incubation period
chronic carriers
...
herd immunity
immunity enjoyed by a large portion of a population that reduces disease transmission among non-immune individuals
isolation
the patient is separated from the general population
quarantine
the seperation of "healthy" population from infected people
notifiable disease
diseases which must be reported to the CDC
nosocomial infections
commonly spread diseases in the hospital; most easily spread are staphylococcus aureus and e. coli
infection control
best way is HANDWASHING