Microbio Terms

Gram Positive

Bacteria turns purple/blue after a Gram Stain Test

Gram Negative

Bacteria turns pink/red after a Gram Stain test because of a thin cell wall and outer membrane that blocks antibiotics

Listeria

• Hardy rod-shaped bacterium

• Found in soil, water, animal waste

• Contaminated foods → unpasteurized dairy, raw veggies, processed meats

• Can grow inside cold fridge

• Gram positive

Salmonella

• Caused by eating raw/undercooked meat, poultry, or eggs

• Gram negative

E. coli

• Bacteria found in intestines of humans and animals

• Some strains cause food poisoning

• Associated with contaminated water and undercooked food

• Gram negative → thin cell wall and outer membrane

Petri film

Ready-to-use sample ready microbiological test systems with culture media, cold-water-soluble gelling agents, and indicator dyes

Aseptic technique

Practices and procedures used to prevent introduction of pathogens in environment

Qualitative

• Quality; type

• Is something there/not there

• Descriptive data

Quantitative

• Number of something

• How many

Serial dilution

Lower concentration of substance by constant factor