Spirochetes 2

• What is the genus of the bacteria that causes leptospirosis?

  Leptospira

  
• What are the morphological characteristics of Leptospira?

  • Tightly coiled and flexible
  • Length: 5-15 µm
  • Width: 0.1-0.2 µm
  • One or two ends usually bent to form a hook-like shape
  • Stains deep brown with silver stain (Fontana stain)
• How can the mobility of Leptospira be observed?

  Using a darkfield microscope
• What are the two species of Leptospira mentioned?

  • L. interrogans
  • L. biflaxa
• What disease does L. interrogans cause?

  Leptospirosis
• How is L. interrogans classified based on antigenic differences?

  It can be divided into at least 24 serogroups and 200 serotypes
• What is the natural habitat of L. biflaxa?

  Water
• What are the culture conditions for L. interrogans?

  • Grown in Korthof medium with 10% rabbit serum
  • Optimal incubating temperature: about 28℃
  • Grows slowly
  • Sensitive to heating and various chemical agents
  • Can survive several months in wet soil and water
• How many chromosomes does L. interrogans have?

  Two chromosomes (one large and one small)
• Where does L. interrogans propagate in infected patients or animals?

  In the kidney
• How does L. interrogans enter the body?

  • Through healthy or broken skin
  • Contaminated soil and water
  • Via urine from infected rodents and farm animals
• What is leptospiremia?

  Rapid entry of L. interrogans into the bloodstream
• What is the epidemiological significance of leptospirosis?

  • It is a common zoonosis
  • Extensive animal hosts include rats, mice, swine, cattle, dogs, and sheep
• What are the virulent factors produced by L. interrogans?

  LPS, hemolysin, cytotoxicity factor (CTF), and cytopathic effect (CPE) substance
• What is the main cause of disease due to L. interrogans?

  Pathological damage to the capillary endothelium
• What internal organs can leptospirosis affect?

  • Lung
  • Kidney
  • Liver
• How do the clinical symptoms of leptospirosis vary?

  They range from mild influenza-like signs to severe outcomes like death
• Which immune cells can phagocytose L. interrogans?

  Macrophages
• What samples are collected for detecting leptospire?

  • Peripheral blood in the first week of disease
  • Urine from the second week on
• What are common diagnostic methods for leptospirosis?

  • Direct darkfield microscopy
  • Serological examination
• What is the first choice drug to treat leptospirosis?

  Penicillin
• What type of vaccine is available for leptospirosis?

  • Multi-valent vaccine composed of whole dead cells of several leptospiral serovars
• What is the causative agent of Lyme disease?

  Borrelia burgdorferi
• When was Lyme disease first identified?

  In 1975
• How do humans become infected with Borrelia burgdorferi?

  By the bite of ticks carrying the bacteria
• What is the clinical characteristic of Lyme disease?

  Erythema chronicum migrans (ECM) at the bite site
• What abilities does Borrelia burgdorferi have regarding host cells?

  It can invade host cells, resist phagocytosis, and produce endotoxin-like substances

  
• What is the morphology of Borrelia burgdorferi?

  • Spiral microorganism
  • Has variable numbers (7-11) of endoflagella for movement

  
• What is the role of ticks in Lyme disease?

  Ticks transmit Borrelia burgdorferi to humans
• What is the characteristic rash associated with Lyme disease?

  • Erythema chronicum migrans (ECM)
• How is Lyme disease diagnosed?

  Based on clinical symptoms and exposure to infected ticks
• What diagnostic methods are helpful for Lyme disease?

  PCR and serological assays
• How can most cases of Lyme disease be treated?

  With a few weeks of antibiotics (penicillin or tetracycline)