kamang

• MacConkey Agar Results

  • Positive (+)
  • Negative (-)
  • Variable (H)
• True Intestinal Pathogens

  • Salmonella
  • Shigella
  • Yersinia
  • Escherichia
• Opportunistic Pathogens


  • Hafnia
  • Escherichia
  • Edwardsiella
  • Enterobacter
  • Morganella
  • Proteus
  • Providencia
  • Serratia
  • Klebsiella
  • Citrobacter
  • Acinetobacter
  • Stenotrophomonas

  
• MacConkey Positive (+) Oxidase Positive (+)


  • Pseudomonas
  • Burkholderia
  • Achromobacter
  • Chryseobacterium
  • Sphingobacterium
  • Alcaligenes
  • Bordetella (Non-Pertussis)
  • Comamonas
  • Vibrio
  • Aeromonas
  • Plesiomonas
  • Chromobacterium
• MacConkey Negative (-) Oxidase Positive (+)


  • Sphingomonas paucimobilis
  • Moraxella
  • Eikenella
  • Pasteurella
  • Kingella
  • Cardiobacterium
  • Capnocytophaga
• MacConkey Negative (-) Oxidase Variable (H)


  • Haemophilus
• Optimally Recovered in Special Media

  • Bartonella
  • Hafnia
  • Campylobacter
  • Arcobacter
  • Legionella
  • Brucella
  • Bordetella Pertussis and B. Parapertussis
  • Francisella
  • Streptobacillus moniliformis
  • Spirillum minus
• Components of MacConkey Agar

  • Crystal violet dye
  • Neutral red pH indicator
  • Bacterial fermentation of lactose results in acid production
• Indicators on Media

  • EMB – eosin y, methylene blue
  • Mac – neutral red
  • Hektoen – bromothymol blue; H2S - ferric ammonium citrate
  • TSI – phenol red; H2S – ferrous sulphate
  • LIA – bromcresol purple; H2S – ferric ammonium citrate
  • Indole – Kovac/Erlich/PABA
  • MR-VP – methyl red
  • CUT – bromthymol blue
  • Decarb – bromcresol purple
  • Urease – phenol red
• LIA

  Lysine iron agar; ability of bacteria to deaminate and decarboxylase
• Lactose and Non-lactose Fermenters Bacteria

  • Rapid LF - EKE
  • Late LF - SaShiSHY
  • Non LF - PPMESSE
• Positive Results of Different Tests


  • acid slant
  • acid butt
  • coloration
  • citrate
• Rapid Urease Producer


  • Proteus
  • Providencia
  • Morganella
• Late Urease Producer

  • Citrobacter
  • Klebsiella
  • Enterobacter
  • Yersinia
  • Serratia
• Unique Reactions (LIA)


  • Salmonella – K/K, H2S (+)
  • Proteus – K/A, H2S (-)
• ONPG Test


  Detects β-galactosidase; Rapid test for identification of late lactose fermenters
• Substrate for ONPG Test is O-nitrophenyl-β-galactopyranoside
• β-galactosidase will hydrolyze ONPG to orthonitrophenol, a yellow product
• Composition of LIA

  • Small amt of CHON
  • CHO source (0.1% glucose)
  • Lysine (1% lysine)
  • pH indicator: Bromcresol purple
  • H2S indicator: ferric ammonium citrate
• Composition of TSI

  • CHON
  • CHO source (Lactose – 10 parts (1%), Sucrose – 10 parts (1%), Glucose – 1 part (0.1%))
  • pH indicator: phenol red
  • H2S indicator: ferrous sulphate
  • Source of sulphur: Na thiosulfate
• Unique Reactions of TSI

  • Salmonella
  • Shigella [S. dysenteriae reaction]
• Enterobacteriaceae Reactions


  • Urine culture
  • Non lactose fermenter
  • Oxidase positive
  • PAD
  • ONPG Tests

  
• Types of E. coli

  • Enterotoxigenic E. coli (ETEC)
  • Enteropathogenic E. coli (EPEC)
  • Enterohemorrhagic E. coli (EHEC) or Verotoxin-producing E. coli (VTEC)
  • Enteroinvasive E. coli
• Sereny Test


  Test for invasiveness; organism is inoculated in guinea pig/rabbit eyes causing purulent conjunctivitis
• Enteroadherent E. coli (EAEC)


  • Produce non fimbrial adhesions that attach organisms to host cells
  • Pathologic mechanism unknown
  • Two different phenotypes (DAEC, EAEC)
• E. coli grows pink in color in MacConkey Agar and may have darker color around the colony due to secretion of the bile salts
• Widal’s Test


  • “O” Ab somatic antigen titer >160 - active infection
  • “H” Ab flagellar antigen > 160 - past infection/immune state
  • High Ab to Vi - carrier state

  
• IMViC Reactions

  • Correlate bacteria always
• E. coli Toxins

  • (+ + - -)
  • S. dysenteriae
  • Rice watery stool Vibrio cholerae
• Proteus


  • Weil-Felix Test; O antigens are a source of Ag for this test
• Unique Names of Bacteria

  • Burkholderia mallei - Glanders bacillus
  • Burkholderia pseudomallei - Whitmore’s bacillus
  • Klebsiella pneumoniae - Friedlander's bacillus
  • E. coli - Colon bacillus
  • Moraxella lacunata - Morax axenfeld / haemophilus duplex
  • Bordetella pertussis - Bordet-gengou bacillus
• Late Lactose Fermenters Bacteria

  • Salmonella arizonae
  • Shigella sonnei
  • Serretia
  • Hafnia
  • Yersinia
• Pneumonia Symptoms

  • Unique type of mucus (mucopurulent, gel like, bloody sputum)
  • Mucoid colonies that tend to coalesce/string due to large capsule
  • Currant jelly-like sputum - K. pneumoniae
• Lactose and Non-lactose Test


  • Memorize
• Straus Test


  • Test to diagnose glanders; male guinea pigs inoculated peritoneally with suspected material
• Thiosulfate Citrate Bile Salts Sucrose (TCBS)

  • Selective and differential; classifies vibrio into sucrose fermenters and non sucrose fermenters
• Sucrose Fermenters

  • Yellow colonies (V. cholerae and V. alginolyticus)
• Non Sucrose Fermenters


  • Green colonies (V. parahaemolyticus, V. vulnificus, V. mimicus)
• Pseudomonas aeruginosa is a common cause of cystic fibrosis/pneumonia
• Wagatsuma Blood Agar

  • Kanagawa Phenomenon; pathogenic strains of V. parahaemolyticus produce hemolysis on a high salt medium