Gram Positive Bacilli Flashcards
General characteristics of Cornybacterium
Pleomorphic gram pos rods, nonspore forming
Diptheria toxin
Produced by bacteriophage that block protein synthesis
Media used for C. diphtheriae
Loeffler’s serum agar
Cystine-tellurite blood agar (CBTA)
Elek test
Immunodiffusion test in which lines of precipitation are produced between toxin produced by org & the purchased antitoxin.
-If pos control precipitation & unknown precipitation lines meet in an arch, then pos for toxin
Metachromatic areas of the Corynebacterium
Babe’s-Ernst granules or nutrient reserves
What are the metachromatic areas of the Corynebacterium stained with?
Stained using methylene blue
What is the common name for the other species of Corynebacterium, other than diphtheria?
diphtheroids
jeikeium, pseudohiphtheriticum, pseudotuberculosis, striatum, ulcerans, urealyticum, xerosis
7 other species of Corynebacteriu that have been implicated with patients who are immunocompromised
Clinical significance of Listeria monocytogenes
Attacks primarily immunocompromised, pregnant women (causing premature labor of still born child), neonates
Listeria monocytogenes macroscopic on plate
Narrow ring of beta hemolysis on SBA, similar to Strep agalactiae
Halophilic Tumbling motility in hanging drop test CAMP test with block hemolysis BE & hippurate hydrolysis + can grow @ 4 C
Listeria monocytogenes biochemical characteristics
Erysipelothrix rhusiopathiae clinical significance
Source: domestic swine - infection through scratches on skin
Characteristic lesions
Gram pos, nonspore forming, pleomorphic rod
H2S production
Non motile
Indole & catalase pos
Erysipelothrix rhusiopathiae characteristics
Where is Lactobacillus NF?
Mouth, GI tract, female genital tract
Clinical significance of Bacillus anthracis (Cutaneous)
Acquired through cuts in hand
Small pimple/papule appears 2-3 days post exposure followed by necrotic eschar
Untreated has 20% mortality rate
Clinical significance of Bacillus anthracis (pulmonary)
Spores are inhaled, alveolar macrophages ingest spores & take them to lymphnodes
Primary symptoms of pulmonary anthracis
2-3 days post inhalation, patients present with shortness of breath, fever, headaches, cough
Secondary symptoms of pulmonary antrhacis
Worsening cough, fever, edema, shock, & 1/2 of patients lead to meningeal symptoms, of which death occurs within 3 days
Clinical significance of Bacillus anthracis (gastrointestinal infection)
Caused by ingestion of spores
<1% of cases worldwide
Symptoms are based on site of infection
Mortality thought to be 100%
Virulence factors of B. anthracis
Spores
Capsule
Exotoxins
B. anthracis spores
Allows it to survive in harsh conditions for years
B. anthracis exotoxins
Edema toxin + protective factor = edema
Lethal toxin + protective factor = death
B. anthracis morphology
No hemolysis - white colony with whirling projections (Medusa head)
Large gram pos rod/spore/bamboo shoots
B. anthracis biochemical tests
Cat pos, string of pearls
