title: Multicolour digital image analysis system for identification of bacteria and concurrent assessment of their respiratory activity.
abstract: OBJECTIVE
  To develop a rapid and simple multicolour digital image analysis system for simultaneous identification of bacteria and assessment of their metabolic activity.
  
  
  RESULTS
  We developed an image analyser capable of distinguishing triple-stained bacterial cells. Bacteria were stained with a nucleic acid stain, a fluorescent antibody and a fluorescent metabolic indicator for enumeration, species identification and assessment of metabolic activity. This multicolour image analyser was used to simultaneously identify Escherichia coli O157:H7 in milk samples and assess their respiratory activity. The images of the triple-stained bacteria were captured using a combination of blue light and u.v. excitation and an epifluorescence microscope and were processed by our image analyser. We found a good correlation between the counts of actively respiring (r = 0.93) and total (r = 0.94) E. coli O157:H7 measured by digital image analysis and visual observation.
  
  
  CONCLUSIONS
  The multicolour digital image analysis system described here was able to quantify active pathogenic micro-organisms within 2 h.
  
  
  CONCLUSIONS
  This multicolour image analysis allows the rapid and simultaneous quantification of bacteria, identification of species and assessment of metabolic activity.
authors.affiliation: Environmental Science and Microbiology, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ogawa
authors.forename: K
authors.initials: K
authors.lastname: Tani
authors.forename: A
authors.initials: A
authors.lastname: Ochiai
authors.forename: N
authors.initials: N
authors.lastname: Yamaguchi
authors.forename: M
authors.initials: M
authors.lastname: Nasu
mesh_terms: D000818:Animals; D002417:Cattle; D015169:Colony Count, Microbial; D003116:Color; D019453:Escherichia coli O157 / Q000302:isolation & purification*; D005516:Food Microbiology; D007090:Image Interpretation, Computer-Assisted; D007091:Image Processing, Computer-Assisted; D008856:Microscopy, Fluorescence; D008892:Milk / Q000382:microbiology*; D013194:Staining and Labeling