6: Classification and Review Flashcards
Neisseria meningitidis
meningitis
speticemia
HUMAN is resirvoir
1–40% nasal CARRIER rate only 0.1% develop disease
direct contact and droplets are transfer agents
daycare, dorms, army barracks
familial transmission doesnt cause disease
skin legions 6-8 hrs after infection
bloodstream and CNS
taxonomy system developed by
Linnaeus
eukaryotes: visual and DNA
bacteria: old and new systems
bacterial Taxonomy old way
staining and metabolism (Burguy’s index)
bacterial taxonomy new way
DNA similarity
why is taxonomy difficult in bacteria
1) binary fission… not sexual reproduction
2) HORIZONTAL gene transfer
no gamates made, just division. constant exchange of DNA
pheonotype
physical traits you can see
genotype
DNA sequencing
sexual isolation
inability to produce viable young
ground squierls example… isolated by geography (even though they can have viable offspring)
conundrum of bacteria
horizontal transfer of DNA
what kind of bacteria evolved ability to infect humans more?
gram negative
Bergey’s Method
mono-associate disease with microbe used the tech we had in 1917 and so on: -Morphology -Oxygen utilization - Biochem Tests - Habitat -Serology
how to do Bergey’s method
MUST grow in PURE culture
difficult… only your bacteria and nothing else can grow
oxygen utelization
biochem test
Habitat
where you find it
may be different species even if they are the same in the other tests
biochem tests
genetic ability of bacteria to metabolize things for ex
differnt bio outcomes
Serology
look at the immune response to the bacteria
Use immune system of the infected to characterize
speciation and SUBspeciation
association with bacteria helps to figure out treatment
Dichotomus Keys
DIFFERNTIAL DIAGNOSIS
Y/N questions, lead to a species or cause of diseae
like 20 questions
MUST be able to differentiate… if all members of group pass the question isn’t useful
differential diagnosis
diagnosis of diseases
API strips
biochem tests strips and test tubes... add bacteria and water lots of tests run at the same time reading color gives answers compare the strips to a table
VITEK 2 System of Identification
better and faster and expensiver
test 5,000 bacteria at a time… in 3 hrs
computerized, no human error in reading a table
Mass spectroscopy
analyze proteins in bacteria
figure out species not outcome
analyze presence or absence of given protein
Core Genome
genes shared by ALL strains
what MAKES you E. coli
Pan Genome
genes that are different between straints are included
ALL GENES combined… both those in common and the different ones
All that E. Coli CAN be
Core and Pan genome when you add the genome of another organism
Core genome is refined (shrinks)
Pan Genome is expanded
Core and Pan genome… is there an upper limit?
add more… core shrinks until it gets to a constant
pan genome increases and plateaus
this makes it hard to define a species… everything has stuff in common and tons of stuff not in common