Lecture 17: Bacteria Lectures

Question 1

Mycoplasma pneumonia cause

Answer 1

primary atypical pneumonia in humans

Question 2

Ureaplasma urealyticum cause

Answer 2

UTI, premature birth, neonatal meningitis and penumonia

Question 3

Lyme Disease

Answer 3

• LD or Lyme borreliosis
• Vector:
  
  • Ticks
• Reservoirs:
  
  • animals (deer, field mice, and woodrats)
• caused by:
  
  • Borrelia burgdorferi (most common in U.S.)
  • B. garinii and B. afzelii (most common in Europe and Asia)
• Clinical manifestation:
• (first symptom: bull’s eye rash, second phase: irregular heartbeat, enchephalitis, third pahse: Arthritis
  
  • 3 stages
    
    • Localized Stage
      
      • develops 1 to 10 days after infection
      • expanding, ring-shaped, skin lesion
      • flu-like symptoms
    • Disseminated Stage
      
      • occurs weeks or months after infection
      • neurological abnormalities, heart inflammation, and arthritis
    • Late Stage
      
      • Occurs years later
      • demyelination of neurons, behavioral changes, and symptoms resembling Alzheimer’s disease and multiple sclerosis
• Diagnosis
  
  • Serolgical testing (Lyme ELISA or Western blot)
  • Isolation of spirochete from patient
  • detection of Borrelia DNA (PCR)
• Treatment, prevention, and control
  
  • antibiotic therapy most effective in early stages
  • tick control and avoiding ticks

Question 4

Relapsing Fever

Answer 4

• symptoms:
  
  • recurring episodes of fever, headache, muscle and joint aches, and nausea
• Causative Agent:
  
  • Borrelia
• Vector:
  
  • Ticks
• Reservoir:
  
  • Rodents

Question 5

Syphilis

Answer 5

• Cause:
  
  • Treponema pallidum subsp. Pallidum
• Three stages of syphilis
  
  • primary: (10-90 days after exposure)
    
    • Chancre (small, painless, reddened ulcer) at infection site that contains spirochetes
  • Secondary stage (3-8 weeks after primary chancre)
    
    • Highly variable skin rash followed by latent period (any surface area of the body including the palms of the hands may have rash)
  • Tertiary stage (up to 10 years after primary chancre)
    
    • formation of gummas (degenerative lesions) in skin, bone, and nervous system
• Diagnosis
  
  • Clincal hx, microscopic examination, and serology
  • Direct diagnosis
    
    • staining with fluorescent-labeled monoclonal antibodies
  • indirect, rapid screening
    
    • VDRL, RPR, EIA
  • Confirming
    
    • FTA-ABS tests for anti-treponemal antibodies
• Treatment, prevention, and control
  
  • Antibiotic therapy most effective in early stages
  • Public education, prompt treatment of new cases, follow-up on sources and contacts, sexual hygiene, and use of condoms.

Question 6

Leptospirosis

Answer 6

• Causative agent
  
  • Leptospira interrogans
• Reservoir
  
  • Dogs and rats
• Transmission
  
  • Skin/mucosal contact from urine-contaminated water
• Symptoms:
  
  • Headaches, muscular aches, fever, kidney failure (possible complication)
• biphasic disease
• if not treated can lead to meningitis, liver failure, respiratory distress (due to bleeding in the lungs), and even death
• Diagnosis:
  
  • serological tests
    
    • growing bacteria form a blood sample, finding microbial DNA in the blood, or antibodies
• Treatment:
  
  • Doxycycline