Additional GNB (non-Enterobacteriaceae) Flashcards
Gram-negative bacillus, pleomorphic, stains poorly
Top 5 cause of pneumonia
Intracellular parasite
Legionella pneumophila
Etiologic agent of Legionellosis; usually pneumonia that occurs in outbreaks instead of single cases – in the top 5 causes of pneumonia
Legionella pneumophila
Virulence: intracellular parasites (i.e. macrophages)
resists killing by superoxide & hydroxyl radicals
inhibits phagosome-lysosome activity
flagella promote invasion
secretes various proteins
Legionella pneumophila
Transmitted by inhaled contaminated water
Legionella pneuomphila
(1) Infrequent agent of superficial wound and urinary tract infections
(2) Mucoid strains repeatedly colonize the respiratory tract of cystic fibrosis patients
Pseudomonas aeruginosa
Gram-negative bacilli
nosocomial infections (~10%), especially in severely compromised or debilitated patients
Virulence factors: protein inhibitors, exotoxins, capsule (cystic fibrosis strains)
Pseudomonas aeruginosa
Gram-negative bacillus, grows on MacConkey
Source – soil & water (prolonged survival on environmental surfaces)
Opportunistic pathogen – post-traumatic wound abscess and septicemia
Acinetobacter baumannii (A-cin-e-to-bac-ter)
Natural & nosocomial
Vietnam, Afghanistan, Iraq
Acinetobacter baumannii
Small Gram-negative coccobacillus, very slow growing (2 weeks to 2 months)
Brucella melitensis & B. abortus
Etiologic agent of Brucellosis (zoonotic disease)
Bangs disease – spontaneous abortion in bovine, sheep, goats
Brucella melitensis & B. abortus
Undulant Fever in humans – acute systemic febrile illness with sweating; initial flu-like symptoms with migratory arthralgia and myalgia (joint & muscle pain), possible neurological symptoms, may lead to bone or joint disease; may be persistent or recurrent (months/years).
Brucella melitensis & B. abortus
Biological threat agent
Transmitted by unpasteurized dairy products (esp. goats) or contact with animal blood or body fluids or tissues (e.g. placenta
Brucella melitensis & B. abortus
Virulence Factors
(1) Intracellual replication
(2) Survives and replicates in phagocytes
Brucella melitensis & B. abortus
Very small Gram-negative bacillus; grows poorly in standard culture media (2-3 days in enriched media)
Biological Select Agent
Francisella tularensis
Ulcerations (2-3 days after exposure) - leads to glandular, nodular, lymph node involvement
Typhoidal (septicemia, systemic)
Pneumonic – similar to typical pneumonia; frequently develops following other forms of ____
tularemia
Francisella tularensis
