Microbiology: A Focus on Bacteria, Fungi, and Viruses Flashcards
How do “bad” pathogens arise from human microbiome
dietary changes
stress
antibiotics
True/false: Majority of pathogens are non-pathogenic
true
What do pathogens do to help them survive?
They constantly evolve by either losing or gaining traits over time
What is the incubation period
The time it takes the pathogen to enter the body and show the first symptom to appear
What does the incubation period depend on
health of host
growth rate of pathogen
degree of exposure
What is the timeline of infection
incubation period –> onset of illness –> period of invasion –> convalescent period
What are the different types of infections
Acute
Chronic
Latent (persistent)
What is an acute infection
Symptoms develop quick
Clears quickly
Host has immunity for reinfection
ex. strep throat
What is chronic infection
Symptoms develop slowly
Can last months to years
ex. tuberculosis
What is latent (persistent) infection
Illness never goes away
It becomes formant in the body and can be awakened with low immunity
ex. syphilis, typhoid, fever, etc.
Carriers: the host may not show symptoms but they spread it to others
What is horizontal transmisson
person to person (horizontal)
ex. blood, saliva, stds, urine
What is vertical transmissoin
Mother to baby via breast milk, delivery, placenta
What is a vector
An animal or arthropod that caries a pathogen and can transfer it to humans
ex. rabies virus transmitted by animal bite
What is virulence?
the degree of pathogenicity of a pathogen (bacteria, fungi, or virus) and is determined by its ability to invade and multiply within the host causing disease
They grow and thrive at the expense of the host
what is a strict pathogen
always causes disease
What is an opportunistic pathogen
part of normal microbial flora
takes advantage of a weakened immune system
caused by the disruption in the microbial flora
breached barrier introduced by a wound
Bacterial Characteristics shapes
Maintained by cell wall of bacteria composed of peptidoglycan
No nucleus –> chromosome forms a structure called a nucleoid
No membrane-bound organelles (prokaryotic)
What are the main shapes of bacteria
cocci
bacilli
spiral
pleomorphic (no defined shape)
What is the cocci shape
Spherical bacteria
What are the different variations of cocci?
Single organisms (cocci)
Pairs (diplococcus)
Chains (streptococcus)
Clusters (staphylococcus)
Tetrads
Sarcina (cube of eight cocci)
What is bacilli
Rod shape
What are the variations of bacilli
Single (bacilli)
Double (diplobacilli)
Chain (streptobacili)
Palisades
What is the intermediate shape between coccus and a bacillus
coccobacilli
What are the shapes of spiral bacteria
Vibrio
Spirillum
Spriochete