The microbiota determined by a variety of factors -age diet hormonal state health personal hygiene The human fetus in a sterile environment the newborn is exposed to microbes from the mother and environment The infant s skin is colonized by micros first followed by the oropharynx, gastrointestinal tract, and other mucosal surfaces
The microbiota determined by a variety of factors: – age – diet – hormonal state – health – personal hygiene • The human fetus in a sterile environment the newborn is exposed to microbes from the mother and environment. • The infant´s skin is colonized by microes first, followed by the oropharynx, gastrointestinal tract, and other mucosal surfaces
Benefits of the normal microbiota Nutrient production/processing eg Vitamin K production by E.co∥ Competition with pathogenic microbes(the first line defense against microbial pathogens) Normal development of the immune system Without microbiota, life would be impossible Opportunistic infections-an infection caused by the normal flora in the hosts environment
• Benefits of the normal microbiota – Nutrient production/processing eg Vitamin K production by E. coli – Competition with pathogenic microbes(the first line defense against microbial pathogens) – Normal development of the immune system Without microbiota, life would be impossible • Opportunistic infections- an infection caused by the normal flora in the host’s environment
The microbial population continues to change in an individual life Y Hospitalization The replacement of normally avirulent bacteria in the oropharynx with Pseudomonas aeruginosa or Klebsiella pneumoniae, that can invade the lungs and cause pneumonia Opportunistic infections in hospital Nosocomial infection √ Antibiotics The growth of Clostridium difficile in the gastrointestinal tract is controlled by the other bacteria present in the intestines Normal (susceptible) bacteria are eliminated by antibiotics and C difficile is able to proliferate and produce gastrointestinal disease
The microbial population continues to change in an individual life Hospitalization The replacement of normally avirulent bacteria in the oropharynx with Pseudomonas aeruginosa or Klebsiella pneumoniae, that can invade the lungs and cause pneumonia • Opportunistic infections in hospital – Nosocomial infection Antibiotics The growth of Clostridium difficile in the gastrointestinal tract is controlled by the other bacteria present in the intestines. Normal (susceptible) bacteria are eliminated by antibiotics and C.difficile is able to proliferate and produce gastrointestinal disease
Outcomes of exposure to bacteria Transiently colonize in the person Permanently colonize in the person nduce disease Colonization f disease ≠ infection
Outcomes of exposure to bacteria • Transiently colonize in the person. • Permanently colonize in the person. • Induce disease. Colonization ≠ disease ≠ infection
Opportunistic pathogens e.g. bacteria that are typically members of the human s normal microflora( Staphylococcus aureus, Escherichia coli and other) Strict pathogens always associated with human diseases” Mycobacterium tuberculosis Neisseria gonorrhoeae Francisella tularensis Rabies virus
• Opportunistic pathogens: – e.g. bacteria that are typically members of the human´s normal microflora (Staphylococcus aureus, Escherichia coli and other) • Strict pathogens “always associated with human diseases” Mycobacterium tuberculosis, Neisseria gonorrhoeae Francisella tularensis, Rabies virus …