Bacteria I & II - Bacteria Pathogenicity and Clinical Significance Flashcards
Understand the basic classification, pathogenicity and clinical significance of major groups of bacteria.
Staphylococcus aureus
Basic Classification: Aerobic Gram Positive Cocci
- TSST1
- Enterotoxins
- Skin and soft tissue infections
- Necrotizing fasciitis
- Osteomyelitis
- Endocarditis
- Toxic shock syndrome
- Cystic fibrosis pneumonia
- Diarrhea
Coagulase negative staphylococci (i.e. Staphylococcus epidermidis)
Basic Classification: Aerobic Gram Positive Cocci
-Biofilm production

-Nosocomial blood stream infections associated with IV catheters
-Prosthetic material infections
Group A Streptococcus (Streptococcus pyogenes)
β-hemolytic
Basic Classification: Aerobic Gram Positive Cocci
-Streptolysin O &S
• Pharyngitis • Necrotizing Fasciitis • Rheumatic fever • Streptococcal Toxic Shock Syndrome(STSS)
Group B Streptococcus (Streptococcus agalactiae)
β-hemolytic
Basic Classification: Aerobic Gram Positive Cocci
-Polysaccharide capsule
- Early onset neonatal disease (pneumonia, sepsis)
- Late onset neonatal disease (meningitis, sepsis)
Streptococcus pneumoniae
α-hemolytic
Basic Classification: Aerobic Gram Positive Cocci
-Polysaccharide capsule
- Community acquired pneumonia
- Otitis media
- Conjunctivitis
- Meningitis
Streptococcus mitis
α-hemolytic
Basic Classification: Aerobic Gram Positive Cocci
-Polysaccharide capsule
- Native valve endocarditis
- Bacteremia
Enterococci (non-hemolytic)
Basic Classification: Aerobic Gram Positive Cocci
-Surface adhesins
- Urinary tract infections
- Endocarditis
- Nosocomial VRE
Corynbacterium diphtheriae
Basic Classification: Aerobic Gram Positive Bacilli
-Diphtheria toxin
• Diphtheria (pharyngeal)
Corynebacterium jeikeium
Basic Classification: Aerobic Gram Positive Bacilli
-Unknown
• Foreign-body infections
Listeria monocytogenes
Basic Classification: Aerobic Gram Positive Bacilli
-Hemolysin
• Gastroenteritis
• Meningitis/Encephalitis
• Pregnancy: abortion,
stillbirth, preterm labor
Peptostreptococcus spp
Basic Classification: Anaerobic Gram Positive Cocci
-Unknown
• Mixed anaerobic and aerobic bacterial infections including: cutaneous, respiratory, oral or female pelvic infections
Actinomyces israelii
Basic Classification: Anaerobic Gram Positive Bacilli
-Unknown
- Oral/cervicofacial infections
- Pelvic infections (IUD)
Clostridium tetani
Basic Classification: Anaerobic Gram Positive Bacilli
-Tetanus toxin
• Tetanus
Clostridium perfringens
Basic Classification: Anaerobic Gram Positive Bacilli
-α - toxin Enterotoxins
• Gas gangrene
• Diarrhea/Bloody, acute
necrotizing GI infection
Clostridium botulinum
Basic Classification: Anaerobic Gram Positive Bacilli
-Neurotoxin
• Botulism (flaccid paralysis)
Clostridium difficile
Basic Classification: Anaerobic Gram Positive Bacilli
-Toxin A and Toxin B
• Diarrhea (antibiotic or hospital acquired)
Escherichia coli
Basic Classification: Aerobic Gram Negative Fermenters
-Endotoxin, exotoxins, capsule, pili
- Meningitis in newborns
- Urinary tract infection
- Gastrointestinal infection
Enterobacter spp
Basic Classification: Aerobic Gram Negative Fermenters
- Exotoxins
- Endotoxins
- Capsules
- Urinary tract infection
- Nosocomial infections
- Blood infections
Salmonella spp
Basic Classification: Aerobic Gram Negative Fermenters
-Adhesion proteins, survival in phagocytes, dissemination to other tissues
- Gastrointestinal infection
- Bacteremia
Proteus spp
Basic Classification: Aerobic Gram Negative Fermenters
- Exotoxins
- Endotoxins
- Capsules
- Adhesion proteins
- Urinary tract infection
- Nosocomial infections
- Blood infections
Vibrio cholerae
Basic Classification: Aerobic Gram Negative Fermenters
-Somatic O antigens Exotoxins
• Cholera (GI infections)
Moraxella catarrhalis
Basic Classification: Aerobic Gram Negative Non-fermenters
-Uncertain, cell envelope adhesion factors
• Community acquired pneumonia
Pseudomonas aeruginosa
Basic Classification: Aerobic Gram Negative Non-fermenters
-Exotoxin A, endotoxins
• Otitis externa • Pneumonia in cystic fibrosis • Ventilator acquired pneumonia • Urinary tract infection
Haemophilus influenzae
Basic Classification: Fastidious Gram Negative Bacilli/Cocci/Coccobacilli
-Polysaccharide capsule, Outer membrane protein
- Meningitis
- Epiglottitis
- Conjunctivitis
- Otitis media
- Pneumonia
Neisseria meningitidis
Basic Classification: Fastidious Gram Negative Bacilli/Cocci/Coccobacilli
-Polysaccharide capsule,
Outer membrane protein
• Meningitis
Neisseria gonorrhea
Basic Classification: Fastidious Gram Negative Bacilli/Cocci/Coccobacilli
-Pili, Capsule, Proteases, Adherence proteins
- Gonorrhea
- Pharyngitis
- Conjunctivitis
Bacteroides fragilis
Basic Classification: Anaerobic Gram Negative
- Capsules
- Endotoxins
- Enzymes
- Abscesses throughout body
- Bacteremia
- Aspiration pneumonia
Helicobacter pylori
Basic Classification: Spirochetes/spiral bacteria
- acid resistance
- establishes residence in the stomach
-duodenal and gastric ulcers
Treponema pallidum
Basic Classification: Spirochetes/spiral bacteria
- lack of proteins on outer membrane of cell wall
- antigenic variation
- 1 syphilis: painless chancre
- 2 syphilis: myalgia, headache, fever, rash
- 3 syphilis: neurosyphilis (general paralysis, tabes dorsalis) cardiovascular syphilis (aortic lesions, heart failure)
- congenital syphilis (facial and tooth abnormalities)
Mycobacterium tuberculosis
Basic Classification: Acid-fast bacilli
- survive and multiply in alveolar macrophages
- carried to lymphatics and can start other foci of infection
- primary pulmonary disease
- reactivation disease
- disseminated disease (kidney, bones, etc.)
- world-wide issue of public health concern
Mycobacterium avium complex
Basic Classification: Acid-fast bacilli
-inhibition of lysosome-phagosome fusion
- pulmonary disease
- disseminated infection in AIDS patients
- opportunistic infection in immunocompromised hosts
Genital mycoplasma (M. hominis, M. genitalium)
Basic Classification: Non gram staining bacteria
- resistant to beta-lactam antibiotics
- non-gonococcal urethritis in males
Mycoplasma pneumoniae
Basic Classification: Non gram staining bacteria
- polyclonal T-cell and B-cell activators
- trigger formation of cold agglutinins (clump RBCs)
- atypical pneumonia
- dermatologic involvement
- cardiac and neurologic complications
Chlamydia trachomatis
Basic Classification: Obligate intracellular bacteria
- complicated intracellular lifecycle
- inhibits phagosome-lysosome fusion
- urethritis
- epididymitis
- proctitis
- cervicitis
- PID
- conjunctivitis
- infant: conjunctivitis, pneumonitis
- lymphogranuloma venereum
Chlamydophila psittaci
Basic Classification: Obligate intracellular bacteria
- Vertebrate vector: birds
- atypical pneumonia
Rickettsia rickettsii
Basic Classification: Obligate intracellular bacteria
- Tick vector: Dermacentor spp
- cell to cell spread (hundreds of contiguous infected epithelial cells)
-Rocky Mountain spotted fever (fever and rash)
