Lab 09: Carbohydrate Metabolism and Enterobacteraceae Micro20

Flashcards containing key vocabulary and definitions related to carbohydrate metabolism and Enterobacteraceae, aiding in exam preparation.

Enterobacteriaceae

A large family of Gram-negative bacteria that includes many harmless symbionts and pathogens.

Facultative Anaerobes

Organisms that can grow in the presence or absence of oxygen.

Coliform

Rod-shaped, gram-negative bacteria that can ferment lactose, used as an indicator of sanitary quality.

Non-coliform

Bacteria that cannot ferment lactose, typically pathogenic.

Oxidase Negative

A characteristic of bacteria that do not produce cytochrome oxidase.

Phenol Red Broth

Differential media used to detect fermentation pathways; yellow indicates acid production. Bubbles indicate gas production.

Simmons Citrate Utilization Test

Differential medium to test if an organism can utilize citrate as its sole carbon source. pH indicator is bromthymol blue; green indicates a negative result, blue indicates a positive result.

TSI Agar

Triple Sugar Iron agar used to evaluate fermentation of sugars and production of hydrogen sulfide. Slant is red if no acid is produced, yellow if acid is produced, and may show black precipitate if hydrogen sulfide is present.

E. coli O157:H7

A strain of E. coli known to cause hemorrhagic colitis and hemolytic uremic syndrome.

Lactose Fermentation

The process by which bacteria convert lactose into lactic acid.

Gastroenteritis

Inflammation of the stomach and intestines often caused by infections.

Shiga Toxin

A toxin produced by certain pathogenic strains of E. coli that can damage the intestinal lining.

MR-VP Test

A combined test used to differentiate enteric bacteria based on their fermentation pathways.

Salmonella Typhimurium

Enteric Pathogen that causes gastroenteritis and foodborne illness.

Shigella Dysenteriae

A pathogenic species of Shigella that causes severe diarrhea and dysentery, primarily through fecal-oral transmission.

TSA Triple Sugar Irion Agar

A differential medium used to identify gram-negative enteric bacteria by detecting their ability to ferment glucose, lactose, and sucrose, as well as produce hydrogen sulfide.

EMB Agar

Selective medium for enteric, differential media for lactose fermentation. Indicator dye is eosin Y and methylene blue.

E. Coli

Black/Mettalic green colonies on EMB indicate lactose fermentation and acidic byproducts.

E. areogenes

Pink colonies indicate lactose fermentation on EMB agar. Little bit of fermentation.

S. typhimurium

Produces colorless colonies on EMB agar, indicating non-lactose fermentation.

MRS Agar

A selective medium used for isolating Lactobacillus species, it contains deionized water, glucose, peptonized milk, and various additives to promote growth.

MR-VP

A type of broth used to differentiate between bacteria based on their ability to ferment glucose and produce acids or alcohol. It stands for Methyl Red and Voges-Proskauer tests.

Positive MR-VP Test

Indicates that a bacterium ferments glucose and produces either acids for the Methyl Red test or acetoin for the Voges-Proskauer test. Red Color!

Negative MR-VP Test

Indicates that a bacterium does not ferment glucose or produce acids for the Methyl Red test, nor acetoin for the Voges-Proskauer test. Colorless!