Microbiology Notes on Gram-Negative Bacteria

A comprehensive set of flashcards covering key terms and definitions related to Gram-negative bacteria, their characteristics, and biochemical tests.

Neisseria

A genus of Gram-negative cocci known for species like N. gonorrhoeae and N. meningitidis.

N. gonorrhoeae

Causes gonorrhea, may be asymptomatic, grows on Chocolate and Thayer Martin agar, and ferments glucose.

Meningitis

An infection caused by N. meningitidis, primarily affecting children under 3 years.

Waterhouse-Friderichsen syndrome

A severe form of meningococcemia characterized by scattered petechiae.

Moraxella catarrhalis

Gram-negative cocci that cause respiratory infections and is often beta-lactamase positive.

Acinetobacter

A genus of emerging pathogens responsible for respiratory infections and urinary tract infections.

Escherichia coli (E. coli)

A major cause of urinary tract infections and gastrointestinal infections; lactose positive.

Shigella

A pathogen that causes bacillary dysentery, often associated with food poisoning.

Klebsiella pneumoniae

An opportunistic pathogen causing pneumonia, urinary tract infections, and characterized by a polysaccharide capsule.

Salmonella

A genus of bacteria commonly responsible for foodborne illness and enteric infections.

Urease test

A biochemical test that determines the ability of an organism to hydrolyze urea to ammonia.

Triple Sugar Iron (TSI) agar

A differential medium used to identify Enterobacteriaceae based on sugar fermentation patterns.

Lactose fermentation

The ability of an organism to utilize lactose as a carbon source, distinguished by a color change in media.

Oxidase test

A biochemical test that identifies organisms that produce cytochrome c oxidase.

Hemolytic Uremic Syndrome (HUS)

A condition often triggered by certain strains of E. coli, leading to kidney failure.

Biochemical reactions

Tests conducted to identify and differentiate bacterial species based on metabolic capabilities.