Identification and enumeration of Salmonella on sample slides of poultry carcass wash water using image analysis with fluorescent microscopy

Rapid detection of bacteria on poultry carcasses is desirable for the poult ry industry to enhance food safety of poultry products. This research focus ed on image analysis with fluorescent microscopy for identification and enu meration of Salmonella typhimurium on sample slides of poultry carcass wash water which were prepared using fluorescent antibodies and immune-magnetic beads. The criteria of morphological and optical characteristics of S. typ himurium cells, including area, aspect ratio, diameter major and minor axis , maximum and minimum radii, perimeter radius ratio, length and width, and intensity were developed. An algorithm that included channel extracting, me dian filtering, image sharpening, image dilation and erosion, image flatten ing, and watershed filtering was selected using Image-Pro(R) Plus software to analyze the acquired images. The algorithm was trained with 110 slide sa mples. The regression analysis showed that the relationship between the aut omatic image counting and the microbial plate counting was linear with a co rrelation coefficient of 0.88. The detection limit of this method was 1 x 1 0(4) cells/mL, and the time needed was less than 4 h.