Unit 9: Gram Negative Cocci

Vocabulary flashcards generated from the Clinical Bacteriology lecture notes covering Gram-Negative Cocci, including Neisseria species, Moraxella catarrhalis, and Veillonella parvula.

Neisseria gonorrhoeae

A fastidious, gram-negative intracellular or extracellular diplococcus that ferments glucose only, requires enriched CAP for growth, and acts as the causative agent of gonorrhea and disseminated infections.

Neisseria meningitidis

An encapsulated, gram-negative diplococcus that ferments glucose and maltose, requires iron for growth, and is the leading cause of fatal bacterial meningitis.

Neisseria weaveri

A rod-shaped gram-negative bacillus that is part of the normal oral microbiota in dogs and acts as a primary pathogen to dogs.

Simonsiella

A motile bacterium with gliding motility in the Neisseriaceae family that forms large, flat, multicellular filaments and is part of the normal human oral biota.

Common Pili

The principal virulence factor of Neisseria gonorrhoeae that mediates attachment to mucosal cells, prevents phagocytosis by neutrophils, and allows genetic material exchange.

T1-T2 Colonies

Primary culture colonies of Neisseria gonorrhoeae that possess pili, are virulent, appear small and dome-shaped, and look bright in reflected light.

T3-T5 Colonies

Subsequent culture colonies of Neisseria gonorrhoeae that are devoid of pili, avirulent, and present as larger, flatter colonies.

porB

An outer membrane protein in Neisseria gonorrhoeae that protects the organism against the host's inflammatory response and serum complement-mediated killing.

Protein II (Opa)

An outer membrane opacity protein in Neisseria gonorrhoeae that facilitates adherence to host phagocytic and epithelial cells.

Protein III (Rmp)

A reduction modified outer membrane protein in Neisseria gonorrhoeae that blocks the bactericidal effect of host IgG.

IgA Protease

An enzyme produced by Neisseria gonorrhoeae and Neisseria meningitidis that cleaves IgA on mucosal surfaces.

Ophthalmia Neonatorum

A gonococcal eye infection in newborns acquired during vaginal delivery through an infected birth canal, which can lead to blindness if untreated.

Crede's Prophylaxis

A preventive ocular treatment for newborns consisting of $1$ to $2$ drops of 1\text{\null}\times10^{-2} ($1\text{\%}$) silver nitrate solution placed in the eyes at birth.

Fitz-Hugh-Curtis Syndrome

Perihepatitis occurring as a complication of Pelvic Inflammatory Disease (PID) secondary to gonococcal cervicitis.

AHU Strain

Strains of Neisseria gonorrhoeae requiring Arginine, Hypoxanthine, and Uracil, associated with asymptomatic infections in men and blood-borne dissemination causing virulent arthritis.

JEMBEC System

A commercial transport chamber (James E. Martin Biological Environmental Chamber) containing MTM medium and a CO2-generating tablet composed of sodium bicarbonate and citric acid.

Thayer-Martin Medium

A selective culture medium composed of chocolate agar with IsoVitaleX enrichment supplement and the antibiotics colistin, vancomycin, and nystatin.

Modified Thayer-Martin Medium (MTM)

Thayer-Martin medium supplemented with trimethoprim lactate to inhibit the swarming of Proteus species.

Martin-Lewis (ML) Medium

A selective medium similar to MTM that substitutes anisomycin for nystatin and contains a higher concentration of vancomycin.

New York City (NYC) Medium

A transparent selective medium containing lysed horse blood, horse plasma, yeast dialysate, and antibiotics, which supports the growth of Mycoplasma hominis and Ureaplasma urealyticum.

GC-Lect Medium

A selective medium containing vancomycin, lincomycin, colistin, amphotericin B, and trimethoprim designed to inhibit oropharyngeal normal flora.

Superoxol Test

A rapid biochemical test utilizing $30\text{\%}$ $\text{H}_2\text{O}_2$ as the reagent, where a positive result of vigorous bubbling identifies Neisseria gonorrhoeae.

Limulus Test

A rapid screening test for Neisseria gonorrhoeae that detects lipopolysaccharide endotoxin.

Waterhouse-Friderichsen Syndrome

A fulminating, highly fatal manifestation of meningococcemia characterized by hemorrhage into the adrenal glands, a hypoadrennergic state, DIC, and septic shock.

Purpura

Hemorrhaging of blood into the skin and mucous membranes producing bruises, characteristic of severe meningococcemia.

Petechial Skin Rash

Pinpoint red spots on the skin caused by minute tissue hemorrhages during meningococcemia.

Neisseria cinerea

A commensal Neisseria species susceptible to colistin (10\text{\null}\times10^{-6}\text{g} disk, $\ge10\text{ mm}$ ZOI) with colonies resembling T3 colonies of N. gonorrhoeae, capable of causing opportunistic bacteremia or pneumonia.

Neisseria flavescens

A yellow-pigmented, asaccharolytic Neisseria species capable of growing on BAP and CAP at $22^\text{o}\text{C}$.

Neisseria lactamica

A commensal Neisseria species found in the nasopharynx of infants and children; it is the only Neisseria species that utilizes lactose and is ONPG positive.

Neisseria mucosa

A Neisseria species with large, mucoid colonies that adhere to agar, reduces nitrite to nitrogen gas, and grows on Nutrient Agar at $35^\text{o}\text{C}$.

Neisseria polysaccharea

A Neisseria species that ferments glucose, maltose, and rarely sucrose, producing abundant extracellular polysaccharide in media containing $1\text{\%}$ or $5\text{\%}$ sucrose.

Neisseria sicca

A commensal Neisseria species characterized by dry, wrinkled, adherent, and breadcrumb-like colonies.

Neisseria subflava

A Neisseria species meaning 'less yellow', consisting of three biovars (subflava, flava, and perflava).

Neisseria elongata

A rod-shaped, catalase-negative Neisseria species divided into three subspecies: elongata, glycolytica, and nitroreducens.

Moraxella catarrhalis

A non-motile, fastidious, beta-lactamase-producing, gram-negative diplococcus part of normal URT flora that causes otitis media in children and respiratory infections.

Hockey Puck Appearance

The characteristic property of young Moraxella catarrhalis colonies on BAP/CAP where intact colonies can be pushed across the agar surface with a loop.

Wagon-Wheel Appearance

The characteristic morphology displayed by older colonies of Moraxella catarrhalis on chocolate agar.

Butyrate Esterase / Tributyrin Test

A definitive enzymatic test for Moraxella catarrhalis using bromo-chloro-indolyl butyrate as substrate, yielding a positive blue reaction.

Veillonella parvula

A tiny, strictly anaerobic gram-negative diplococcus/coccus in normal oral flora that produces propionic and acetic acid and displays red fluorescence under long-wave UV light.

Group 1 Neisseria Species

The group of primary human pathogens within the Neisseria genus, consisting of Neisseria gonorrhoeae and Neisseria meningitidis.

Group 2 Neisseria Species

The category of commensal Neisseria species capable of growing on selective media.

Group 3 Neisseria Species

The category of commensal Neisseria species that do not grow on selective media.