bacteriologic examination of water: coliform counts

• killing of all present living microbes

  sterilization
• removal of microbes in an object

  disinfection
• cleaning; removal of decontaminated area

  decontamination
• an agent used for disinfecting an area/object but is too toxic for human tissues

  disinfectant
• also used to remove the infected areas from microbes but is safe to use for human tissues

  antiseptic
• removes (not kill) microbial numbers in an area

  sanitizer
• an action that kills microbes

  cidal action
• action that inhibits growth of microbial bacterias

  static action
• most common agent used in killing microbes

  temperature
• things to consider when controlling microbial growth

  • concentration
  • length of exposure
  • intensity of the agent
  • number of organisms
  • temperature
  • organism itself
  • nature of the one bearing the organism
• this temp is cidal in action and kills microbes

  above the maximum
• temp that is static in action that slows down metabolism of bacterial growth

  below the minimum
• purpose of this action is to determine if there is a pathogen present in the water

  bacteriological examination of the coliform count
• diseases that could be transmitted by fecally contaminated water


  salmonellosis, hepatitis a, cholera, typhoid fever, shigellosis,
• coliforms are what gram? negative or positive

  gram negative
• what family does coliforms belongs to?

  Enterobacteriaceae
• example of a fecal coliform present in the intestines of animals and humans

  Escherichia coli or E. coli
• what indicates the presence of coliforms in water?

  fecal pathogens
• 2 sets in performing quality of water

  fecal coliform count and total coliform count
• it is a test for fecal coliforms only and which produce blue colonies

  fecal coliform count
• for both fecal and non fecal that is usually not as specific as the other one. they produce a metallic green colony.

  total coliform count
• when is the results best shown in an antimicrobial action?

  low microbial numbers
• 2 common microbial modes of actions for disinfectant, antiseptics and sanitizers.

  damage lipids and denature microbial enzymes
• give the 9 common chemical agents used

  • phenol and phenol derivatives
  • soaps and detergents
  • alcohols
  • acids and alkali
  • heavy metals
  • chlorine
  • ethylene oxide gas
  • aldehydes
  • iodine and iodophors
• was the first disinfectant used but is too toxic and has a strong smell

  phenol
• includes orthophenylphenol, hexachlorophene, and triclosan

  phenol derivatives
• chlorine-containing phenolic antiseptic very common in antimicrobial soaps

  triclosan
• ineffective against endospores

  phenol and phenol derivatives
• mildly microbial and removes microbes by breaking down oily films in the skin

  soap and detergents
• removal of the oily film of the skin is called what?

  emulsification
• detergents may be what?

  anionic and cationic
• anionic are what charged?

  negatively charged
• cationic are what charged?

  positively charged
• 70% of these solutions are effective in killing vegetative bacteria but are ineffective against endospores

  alcohol
• they alter membrane permeability and other molecules.

  acid and alkalis
• mercury, silver, copper


  heavy metals
• reacts with water to form hypochlorite ions and is used for chlorination of drinking water and swimming pools

  chlorine
• denatures microbial proteins

  iodines
• less irritating than iodine and does not stain. it is the result of the combination of iodine and inert polymer like polyvinylpyrrolidone

  iodophors
• used in embalming

  formalin