Lab 12: Neisseria and Moraxella Laboratory Identification

Vocabulary flashcards covering microscopic and colonial characteristics, specimen collection, transport, and identification procedures for Neisseria species and Moraxella catarrhalis.

Diplococci

Gram-negative cocci that are usually found in pairs with flattened adjacent sides, often characterized as kidney-bean or coffee-bean shaped.

Neisseria gonorrhoeae

A fastidious human pathogen causing the sexually transmitted infection gonorrhea, requiring enriched selective media (such as Thayer-Martin or New York City agar) and a CO2 atmosphere for primary isolation.

Ophthalmia neonatorum

An acute eye infection in neonates caused by Neisseria gonorrhoeae transmitted as the infant passes through an infected birth canal.

Gonococcal Specimen Collection Swabs

Swabs composed of Dacron or rayon, used because traditional cotton and calcium alginate swabs contain components that are toxic and inhibitory to Neisseria gonorrhoeae.

Non-nutritive Transport Media

Holding media, such as Stuart's and Amies transport systems, designed to preserve viability for up to 12 hours at room temperature by protecting gonococci from drying, oxygen, and toxic fatty acids.

Nutritive Transport Systems

Commercial media systems (e.g., Transgrow, JEMBEC, Gono-pack, InTray®GC) containing selective growth agar and a CO2-generating mechanism to sustain Neisseria gonorrhoeae when specimen transit is delayed.

Superoxol Test

A rapid spot identification test using 30% hydrogen peroxide ($H_2O_2$) that yields immediate, vigorous bubbling with Neisseria gonorrhoeae, distinguishing it from other Neisseria species which give negative or weak reactions.

Thornsberry Method

A beta-lactamase detection procedure utilizing Cefinase disks impregnated with nitrocefin, which produces a deep pink color within 10 minutes upon enzymatic cleavage of the beta-lactam ring.

Waterhouse-Friderichsen Syndrome

A severe, fulminant form of meningococcemia caused by Neisseria meningitidis that typically leads to petechiae and multiple organ failure.

Neisseria meningitidis

A primary human pathogen responsible for epidemic meningitis and meningococcemia, which can also reside as normal mucosal flora in the nasopharynx of 30% of asymptomatic individuals.

ONPG Test

A rapid o-nitrophenyl-ß-D-galacto-pyranoside test detecting beta-galactosidase activity to differentiate lactose-fermenting Neisseria lactamica (positive) from Neisseria meningitidis (negative).

Neisseria lactamica

A commensal species of the nasopharynx in children and adolescents that produces beta-galactosidase to hydrolyze lactose and can grow on simple nutrient agar.

Moraxella catarrhalis

An aerobic, asaccharolytic Gram-negative diplococcus forming part of the normal upper respiratory flora of children that causes opportunistic infections and tests positive for DNAse, tributyrin hydrolysis, and nitrate reduction.

"Hockey Puck" Colony Characteristic

A descriptive term for Moraxella catarrhalis colonies grown on blood or chocolate agar, referring to their property of remaining intact and sliding across the plate when pushed with a loop.

Tributyrin Hydrolysis Test

The key differential test for Moraxella catarrhalis, in which bacterial butyrate esterase hydrolyzes tributyrin to release butyric acid, causing a color change from a pH decrease.

CTA Sugars

Cystine trypticase agar tubes containing 1% or 2% carbohydrate and phenol red indicator, used to evaluate oxidative carbohydrate degradation (turning yellow in acid) under loose caps in an $O_2$ atmosphere.

Urogenital Specimen Guidelines for Symptomatic Patients

Specimen recommendations for symptomatic males and females across NAAT, Gram stain, and culture diagnostics.

Direct Smear Quantification Scale

Standard microbiology grading scheme for counting cells and bacteria per oil immersion field: + (scant, 1-2 per several fields), ++ (few,