Aerobic Gram Positive Bacilli Flashcards
Bacillus Basics
characteristics, 2 species, where for each, trans for each
Special: spore forming rod
- B. anthracis
- B. cereus
Habitat
- B anthracis: soil, non vaccinated animal areas
- B. cereus: soil
Transmission
- B. anthracis: contact with infected animals, inhale spores, spore through skin or mucous membrane, sometimes ingestion
- B. cereus: traumatic introduction, contam. food
Bacillus Infection Overview
for both species, safety, treatment
B. anthracis: anthrax
WHITE POWDER
- If active: BSL 3 environment
- Vaccine for high risk
B. cereus: food poisoning, opportunistic
- Antibiotics
- Food handling
Bacillus Infection: Anthrax
3 forms
Cutaneous
- Papule progresses to ulceration, lymphadenopathy, systemic signs
- 20% mortality if untreated
Pulmonary
- Wool sorter’s disease
- Fever, chills, dizziness, fatal outcome, prolonged or latent period, enlarged mediastinal lymph node
Gastrointestinal
- Fever chills, diarrhea, bloody vomit
- More rare, most fatal
Bacillus Anthracis Virulence Factors
2
Polypeptide capsule: protects from serum, phagocytes, and engulfment, helps establishes infection
Exotoxin: protective antigen + edema and lethal factor
- Protective antigen helps attach to host cell, one of the factors gets inside
- Edema creates fluid and lethal causes lesions
Bacillus Cereus Infection: Food Poisoning
2 ways
Heat stable: emetic form
- Spores survive and cooking doesnt destroyed
- Enterotoxin ingested
Heat labile: diarrheal form
- Organism ingested and enterotoxin produced inside
Bacillus Cereus Infection: Emetic Form Food Poisoning
what foods, how to get it, term, symptoms
Rice or beans
- Bacteria killed but spores survive
- Enterotoxin released and not destroyed when reheated
- Intoxication: caused by entertoxin and not the bacteria
Symptoms: vomiting nausea cramps, 8-10 hour duration
Bacillus Cereus Infection: Diarrheal Form Food Poisoning
term, how, symptoms
True infection
- Ingesting bacteria in meat, veggies, sauce
- Bacteria multiply in GI tract, releases the heat labile enterotoxin
Symptoms: diarrhea, nausea, cramps, ~1 day duration
Corynebacterium Basics
type, species, where, trans, clinical
Type: diphtheroids, pleomorphic, club shaped with V/L formation, palisade sandwiches
Species: C. diphtheriae and other diphtheroids
Where: C. diphtheriae in nasopharynx, not normal flora but carriers, other diphtheroids in skin flora and animals, water, soil and air
Transmission: C. diphtheriae in person to person respiratory or direct contact with lesions, others are endogenous
Clinical: opportunistic in immunocompromised
Corynebacterium Diphtheriae Virulence
Diphtheria toxin
- Exotoxin
- Bacteriophage with two subunits for attachment and incorporation
- Effects protein synthesis - kills cells
Corynebacterium Infection: Diphtheria
where, symptoms, characteristics.systemic?
Where: worldwide, poor crowded areas
Symptoms: some asymptomatic carriers
- Exudative pharyngitis with pseudomembrane, white layer in mouth, sore throat, fever, damage from exotoxin
Systemic infections: myocarditis, respiratory and cutaneous
Corunebacterium Jeikeium: Risks and Info
risks, carriage, antibiotics?
Risks: immunocompromised, hematologic disorders, intravascular catheters
Carriage in healthy people: uncommon, hospital pts can be colonized
Antibiotics: very resistant
Corynebacterium Urealyticum
Where, substance, symptom, risks
Where: urinary tract
Substance: urease producer
Symptom: renal stones
Risks: immunosuppression, underlying genitourinary disorders, previous antibiotic therapy
General Diphtheria Treatments
3 main
- Antitoxin
- Antibiotics
- DPT vaccine
- Droplet/contact precautions
Listeria Monocytogenes: Basics
type, where, trans
Type: facultative anaerobe, intracellular
Where: soil, vegetation, water, can be in GI tract, cool temps
Transmission: contam. food, soft cheese, cabbage, melons, raw milk, transplacental
Listeria Monocytogenes: Virulence
3
- Adhesion proteins
- Invasion proteins
- Survival in phagocytes
Listeria Monocytogenes: Infection
pregnant women, fetus, elderly
Pregnant women
- 10x more likely
- Hispanic at risk
- Flu like, fever, headache, self limited, no GI symptoms
Fetus or newborn
- Miscarriage, stillbirth, preterm
- Bacteremia/meningitis
- Transplacental more fatal than acquiring after birth
Elderly
- 4x more likely
- CNS and endocarditis
Listeria Monocytogenes: Treatment
Antibiotics
Erysipelothrix: Basics
species, type, where
Species: E. rhusiopathiae
Type: microaerophilic
Where: tonsils, digestive tracts of animals (swine, turkey), hard to dry out, soil for long time
Erysipelothrix: Transmission & Infection
Transmission: zoonotic, butchers, meat workers, vets
- Cutaneous through handling animal products or soil
Infection
Erysipeloid: inflammatory skin lesion
Septicemic: and endocarditis
Gardnerella: Basics
species, where, trans,
Species: G. vaginalis
Where: vaginal flora of 69% of women at reproductive age
Transmission: endogenous
Gardnerella: Infection
Bacterial vaginosis
- Polymicrobial disease
- Reduced Lactobacillus - rise in pH, leads to overgrowth of other microbes
- May cause preterm birth, miscarriage, endometritis
- Increases STI risk
- UTI in men and women
Erysipelothrix & Gardnerella: Treatments
Antibiotics
- Treatment for sexual partners of Gardnerella not needed
- Hygiene
Aerobic Actinomycetes: Basics
Characteristic microscopic, species
Elongate to form branching filamentous forms, partially acid fast
- Nocardia
- Streptomyces
- Gordonia
- Tsukameralla
- Rhodococcus
- Pathogens of immunocompromised
Nocardia: Basics
type, where, transmission
Type: strict aerobes, aerial hyphae, weak acid fast
Where: soil, water, decomposing stuff
Transmission: inoculation or inhalation
Nocardia: Infection
Chronic disease in immunocompromised - T cell defic.
- Cutaneous: mycetoma, cellulitis
- Pulmonary: bronchitis, pneumona
- Dissemination: brain abcesses
