flora

• What is the definition of normal flora or microbiome?

  Microorganisms found in healthy individuals
• What are the four types of flora mentioned?

  Resident flora, transient flora, commensals, carrier state
• What is the origin of normal flora in newborns?

  Newborns are sterile in utero
• What is one beneficial effect of normal flora?

  Immunostimulation through antibody development
• What is a potential source of opportunistic infections?

  Normal flora in patients with impaired defenses
• How can normal flora produce carcinogens?

  By modifying dietary chemicals into carcinogens
• Which areas of the body are typically sterile?

  Internal organs except the alimentary tract
• What maintains sterility in internal organs?

  Local defense mechanisms and chemical substances
• What type of flora is found in the upper respiratory tract?

  Flora similar to that in the mouth
• What is the bacterial concentration in saliva?

  10$^8$ bacteria/ml
• What is the dominant anaerobe in the large intestine?

  Bacteroides fragilis group
• Why is the empty stomach considered sterile?

  Due to gastric acid
• What is the bacterial concentration in feces?

  1/3 of feces weight is bacteria
• What is the significance of Mycobacterium smegmatis in urine?

  It can lead to confusion in diagnosis
• What is the normal bacterial concentration in the female genital tract?

  10$^8$ bacteria/ml
• What is the main skin flora?

  Propionibacterium acnes
• What are the types of normal flora and their characteristics?

  • Commensals: Natural relationship with host
  • Residents: Present for an invariable period
  • Transients: Briefly established, excluded by host defenses
  • Carrier state: Potentially pathogenic organisms
• What are the beneficial effects of normal flora?

  1. Immunostimulation (antibody development)
  2. Exclusionary effect (protection from invaders)
  3. Production of essential nutrients (e.g., vitamins K & B)
  4. May be a source of opportunistic infections
  5. Production of carcinogens from dietary chemicals
• What areas of the body contain normal flora?

  • Gastrointestinal tract: Mouth & large colon
  • Urogenital tract: Vagina & distal urethra
  • Skin: Various regions with different flora
• What are the characteristics of normal flora in the respiratory tract?

  • Upper respiratory tract: Colonized by flora similar to mouth
  • Lower respiratory tract: Sterile
  • Common organisms: Staphylococcus epidermidis, Staphylococcus aureus, Corynebacteria
• What is the role of anaerobic bacteria in the gastrointestinal tract?

  • Maintain anaerobic environment
  • Dominant in large intestine
  • Help in digestion and nutrient absorption
• What is the significance of the reference book mentioned?

  • Title: Sherris Medical Microbiology
  • Authors: Kenneth Ryan / George Ray
  • Focus: Introduction to infectious diseases