Examination of Water Quality Exercise 48

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Examination of Water QualityExercise 48

• Intestinal pathogens
• Vibrio cholerae (cholera)
• Salmonella typhi (typhoid fever)
• Shigella dysenteriae (dysentery)
• Coliforms intestinal bacteria
• Gram-negative
• Facultative anaerobes
• Non-endospore forming rods
• Ferment lactose to produce acid gas at 35C
• Used to determine water purity
• Indicator bacteria (Escherichia coli
  Enterobacter aerogenes)
• Found mainly in the intestines of humans
  warm-blooded animals
• Easily identified able to survive in water
  samples

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• Membrane Filter Method
• 0.45um filter retains bacteria
• Coliforms ferment lactose in Endo broth produce
  acids
• Acids react with basic fuschin dye
• Coliforms have metallic sheen
• Bile salts sodium lauryl sulfate inhibit Gram
  bacteria