CHAP 10&11

• Ecology


  The systematic study of the interrelationships that exist between organisms and their environment
• Microbial Ecology


  The study of the numerous interrelationships between microbes and the world around them
• Indigenous Microflora


  Microorganisms are present both on and in our bodies
• Symbiosis


  Defined as two dissimilar organisms living together in a close association
• Symbionts


  The organisms in the symbiotic relationship
• Neutralism


  A symbiotic relationship in which neither symbiont is affected by the relationship
• Commensalism


  A symbiotic relationship that is beneficial to one symbiont and of no consequence to the other
• Commensals


  The symbionts in a commensalistic relationship
• Mutualism


  A symbiotic relationship that is beneficial to both symbionts
• Parasitism


  A symbiotic relationship that is beneficial to one symbiont (the parasite) and detrimental to the other symbiont (the host)
• Host


  A living organism that harbors another living organism
• Parasite


  May or may not cause disease in the host
• Change in Condition


  Can cause one type of symbiotic relationship to shift to another type
• Lichen


  • An example of mutualistic relationship
• Demodex Mites in Human hair follicles


  • An example of commensalistic relationship
• Cause of African Sleeping Sickness


  • An example of parasitisic relationship
• Escherichia coli


  • An intestinal bacterium that has a mutualistic relationship with humans
• Normal Flora


  Other term for Indigenous Microflora
• Approximately 500-1000 species of indigenous microflora
• Sterile


  Parts of the body like tissue like blood, lymph, spinal fluid, internal tissues and organs that are normally free of microorganisms
• Parts of the body that are sterile

  • Blood
  • Lymph
  • Spinal Fluid
• Staphylococcus spp.


  The most common microflora on the skin
• Factors that affect the number and variety of microorganisms

  • Moisture
  • pH
  • Temperature
  • Salinity
  • Chemical Waste & other Microbes
• Parts of the ear

  • Middle & Inner Ear (usually sterile)
  • Outer Ear and Auditory Canal (contains the same microorganisms as on the skin)
• Carriers


  They harbor virulent pathogens in their nasal passages or throats, but do not have the diseases usually caused by these pathogens
• Lower Respiratory Tract


  Division of the respiratory tract that is usually FREE of microbes
• Diseases resulting from careless dental hygiene

  • Dental Carries
  • Gingivitis
  • Periodontitis
• Alpha-Hemolytic Steptococci


  The most common organisms within the indigenous microflora of the mouth
• Colon (Large Intestine)


  Contains the largest number and variety of microorganisms of any colonized area of the body
• Estimated 500-600 different species of microbes in the colon (large intestine)
• Atmospheric classifications of bacteria present in the colon (large intestine)

  • Obligate
  • Aerotolerant
  • Facultative Anaerobes
• Genitourinary Tract

  Consists of the kidneys, ureters, urinary bladder, urethra, and parts of the female/male reproductive systems
• Parts of the Genitourinary Tract that are usually sterile

  • Kidneys
  • Ureters
  • Urinary Bladder
• Distal Urethra and its External Opening


  Parts of the Genitourinary Tract that harbor many microbes including bacteria, yeasts and viruses
• Microbes that are most frequent causes of urethral infections

  • Chlamydia trachomatis
  • Neisseria gonorrhoeae
  • Mycoplasmas
• Vagina


  Part of the female reproductive system that is NOT sterile
• Beneficial vitamins we get from indigenous microflora

  • Vitamin K
  • Vitamin B12
• Microbial Antagonism


  Microbes versus microbes or microbes against microbes
• Drugs/chemicals produced during microbial antagonism

  • Antibiotics
  • Bacteriocins
• Colicin


  Drug/chemical produced by E. coli during microbial antagonism