SPHU 1020 Exam 3 Guide With
Complete Solution
Definition of medical microbiology (3) - ANSWER study of disease causing
organisms; host response to infection; diagnosis, treatment, prevention of
microbial diseases
agents (4) - ANSWER bacteria, viruses, fungi, parasites
prokaryotes - ANSWER bacteria, rickettsia
eukaryokes - ANSWER fungi, parasites
types of parasites - ANSWER protozoa, helminths
neither prokaryote or eukaryote - ANSWER virus
rickettsia - ANSWER bacteria, behave like virus, obligate intracellular
organism, grow inside cells, can't replicate on own
obligate intracellular organism - ANSWER rickettsia
characteristics of viruses - ANSWER not a cell, intracellular, set of genes in
protein coat, covered by lipid membrane derived from host cell, nucleic acid
either DNA or RNA, replicate using cellular machinery
type of nucleic acid in viruses - ANSWER either DNA or RNA
viruses that infect bacteria - ANSWER bacteriophages
eukaryotic microbes (2) - ANSWER fungi and protozoa
what are protozoa - ANSWER single- celled parasites
,characteristics of bacteria - ANSWER smallest living cells, some have plasmid
what is plasmid (bacteria) - ANSWER extrachromosomal, autonomous, self-
replicating circular pieces of DNA, transfer antibiotic resistance genes
between strands of bacteria
staining with gram stain - ANSWER positive= purple (from thick
pepditoglycan layer), negative= pink
classification of bacteria (3) - ANSWER 1. cocci, 2. bacilli, 3. spirochaetes
cocci shape - ANSWER spherical (ex: strep)
bacilli shape - ANSWER rod shaped/ elongated
spirochaetes shape - ANSWER spiral/ coiled
bacteria- flagella - ANSWER long and colied, motility, can be antigenic
definition of antigenic - ANSWER host immune response triggered by
antibodies
bacteria- fimbria/ pili - ANSWER thin and more common, adherence
bacteria- capsule - ANSWER made of polysaccharide, major virulence factor,
poorly antigenic
bacteria- spores - ANSWER low metabolic state, can be vegetable in body
detecting microbes in lab (4) - ANSWER microscopy, culture, antibody
detection by serology (more common, less expensive), nucleic acid detection
(PCR, DNA probes, most accurate)
inoculation period - ANSWER infection
incubation period - ANSWER no symptoms
, prodromal period - ANSWER no specific symptoms
convalescence period - ANSWER symptoms fade
septicemia - ANSWER extreme response, bacteria in blood, body crashes
where are microbes found? (3) - ANSWER colonization (skin, GI/ respiratory
tract), commensals vs potential pathogens , infection vs disease
commensals vs potential pathogens - ANSWER in body and not harmful vs
right environment for bacteria and potential infection
definition of pathogen - ANSWER virus/ bacterium/ parasite/ fungus
reservoir - ANSWER place where pathogen lives and multiplies
mechanism of transmission - ANSWER how pathogen travels from 1 host to
another, from reservoir to host
susceptible host - ANSWER non-immune, partially immune
vector - ANSWER living, transfers disease to host
chain of infection (6) - ANSWER infectious agent, reservoir, portal of exit,
mode of transmission, portal of entry, susceptible host
true or false: the only good bacterium is a dead bacterium - ANSWER false
(concept of colonization resistance)
how do you prove that a particular organism is the cause of a particular
disease? - ANSWER Koch's postulates
Koch's postulates (4) - ANSWER organism should be found in all cases of the
disease and in lesions of disease, should be possible to grow organism in
Complete Solution
Definition of medical microbiology (3) - ANSWER study of disease causing
organisms; host response to infection; diagnosis, treatment, prevention of
microbial diseases
agents (4) - ANSWER bacteria, viruses, fungi, parasites
prokaryotes - ANSWER bacteria, rickettsia
eukaryokes - ANSWER fungi, parasites
types of parasites - ANSWER protozoa, helminths
neither prokaryote or eukaryote - ANSWER virus
rickettsia - ANSWER bacteria, behave like virus, obligate intracellular
organism, grow inside cells, can't replicate on own
obligate intracellular organism - ANSWER rickettsia
characteristics of viruses - ANSWER not a cell, intracellular, set of genes in
protein coat, covered by lipid membrane derived from host cell, nucleic acid
either DNA or RNA, replicate using cellular machinery
type of nucleic acid in viruses - ANSWER either DNA or RNA
viruses that infect bacteria - ANSWER bacteriophages
eukaryotic microbes (2) - ANSWER fungi and protozoa
what are protozoa - ANSWER single- celled parasites
,characteristics of bacteria - ANSWER smallest living cells, some have plasmid
what is plasmid (bacteria) - ANSWER extrachromosomal, autonomous, self-
replicating circular pieces of DNA, transfer antibiotic resistance genes
between strands of bacteria
staining with gram stain - ANSWER positive= purple (from thick
pepditoglycan layer), negative= pink
classification of bacteria (3) - ANSWER 1. cocci, 2. bacilli, 3. spirochaetes
cocci shape - ANSWER spherical (ex: strep)
bacilli shape - ANSWER rod shaped/ elongated
spirochaetes shape - ANSWER spiral/ coiled
bacteria- flagella - ANSWER long and colied, motility, can be antigenic
definition of antigenic - ANSWER host immune response triggered by
antibodies
bacteria- fimbria/ pili - ANSWER thin and more common, adherence
bacteria- capsule - ANSWER made of polysaccharide, major virulence factor,
poorly antigenic
bacteria- spores - ANSWER low metabolic state, can be vegetable in body
detecting microbes in lab (4) - ANSWER microscopy, culture, antibody
detection by serology (more common, less expensive), nucleic acid detection
(PCR, DNA probes, most accurate)
inoculation period - ANSWER infection
incubation period - ANSWER no symptoms
, prodromal period - ANSWER no specific symptoms
convalescence period - ANSWER symptoms fade
septicemia - ANSWER extreme response, bacteria in blood, body crashes
where are microbes found? (3) - ANSWER colonization (skin, GI/ respiratory
tract), commensals vs potential pathogens , infection vs disease
commensals vs potential pathogens - ANSWER in body and not harmful vs
right environment for bacteria and potential infection
definition of pathogen - ANSWER virus/ bacterium/ parasite/ fungus
reservoir - ANSWER place where pathogen lives and multiplies
mechanism of transmission - ANSWER how pathogen travels from 1 host to
another, from reservoir to host
susceptible host - ANSWER non-immune, partially immune
vector - ANSWER living, transfers disease to host
chain of infection (6) - ANSWER infectious agent, reservoir, portal of exit,
mode of transmission, portal of entry, susceptible host
true or false: the only good bacterium is a dead bacterium - ANSWER false
(concept of colonization resistance)
how do you prove that a particular organism is the cause of a particular
disease? - ANSWER Koch's postulates
Koch's postulates (4) - ANSWER organism should be found in all cases of the
disease and in lesions of disease, should be possible to grow organism in
