MICRO LAB 3 QUIZ--- PATHOGENS

Bacillus anthracis

Disease: Anthrax

Reservoir: In soil

How is it spread: inhailing or ingesting spores, or in wounds

Vaccine: Yes

Gram: Positive

Clostridium botulinum

Disease:Botulism food poising, inablity of muscles to contract

Reservoir: in the soil, bad canned food, low acid foods,

How is it spread: ingesting the neurotoxin (protein toxin released from endospores)

Vaccine: no

Gram: postive

heat will destroy

Clostridium tetani

Disease: Tetanus (lockjaw) (rigid paralysis)

Reservoir: in soil, rusty nails

How is it spread: contaminated wounds and rusted nails

Vaccine: yes

Gram: postivie

Corynebacterium diphtheriae

Disease: Diphtheria ; toxin inhibits protein synthesis on eukaryotic ribosomes

Reservoir: Human to human

How is it spread: respiratory droplets, bacterial growth in the back of throat, releases toxin in blood

Vaccine: yes DTAP

Gram: Positive

Neisseria gonorrhoeae

Disease: Gonorrhea, ophthalmia neonatorum

Reservoir: human to human

How is it spread: contact with infected mucous membranes of the urogenital tract

Vaccine: No

Gram: Negative

Borrelia burgdorferi

Disease: Lyme disease

Reservoir: animals

How is it spread:deer ticks bites

Vaccine: no

Gram: negative

Treponema pallidum

Disease: Syphilis

Reservoir: human to human

How is it spread: direct contact with syphilis

Vaccine: no

Gram: negative

differnetial stain

bacteria will give a differnt result depending on the cell wall chemistry

Gram postive means

purple, the cells of the bacteria have thick peptidoglycan layers,, AKA the ethanol could not break through the strong walls of the the bacteria so the stain will keep the color (stain) purple.

Gram negative means

pink, the cells of the bacteria have a thin layer of peptidoglycan and lays under a cell membrane,, AKA the ethanol is able to break through the membrane and thin layers of the cell, allowing the crystal violet stain to escape. this is why the last step, counterstain is necassary.

What are the four step of gram stain called?

Primary- crystal violet for 30 sec

Mordant- iodine for 30 sec

Decolorization- ethanol for 10-20 sec then water

Counterstain- Gram safranin for 1 minute

what happens if your gram stain is too thick or doesnt destain enough?

all cells will appear gram postive