Standard Plate Count  
              The Standard Plate Count (SPC) means the colony count of the mesophilic bacteria growing under aerobic condition on 
            standard methods agar (Plate Count Agar), and SPC becomes the representative index indicating the degree of the microbial 
            contamination of the food.  In addition, SPC can be used to gauge the general evaluation and judgments such as safety, 
            preservation and sanitary quality of the foods.  Generally, the standard methods agar is used for SPC.  SPC is the number of 
            the colonies on the standard methods agar after 48±3 hours at 35℃±1.0℃ incubation under an aerobic  condition.  
            Therefore, SPC does not include the entire living bacterial population. For example, anaerobic bacteria such as Clostridium 
            perfringens, microaerobic bacteria such as Campylobacter , halophilic bacteria such as Vibrio parahaemolyticus cannot grow 
            on the standard methods agar. 
                              Conception diagram of Standard Plate Count 
                                              Enterohemorrhagic Escherichia coli           Family Enterobacteriaceae 
                                              O26、O111、O157 etc 
                                      Bacillus sp.          E.coli  
                           B.subtilis                              Coli form Group              Salmonella sp. 
                                           Aeromonas sp.               Plesiomonas sp. 
                       B.cereus                                                                       S .Typhi 
                                                                                                               S.ParatyphiA 
             Lactobacillus sp.                                                                           S.Enteritidis 
                                                                                                                Shigella sp. 
            Lactic acid                                                                                      Yersinia sp. 
                                                                                                               （Y.enterocolitica） 
                                                                                                              Pseudomonas sp.
                                                                                                               （P.aeruginosa） 
                                                                                                      Glucose-non-fermenting 
           Bifidobacterium sp.                                                                        Gram-negative,rod-shaped  
                       Enterococcus sp.                                                                  Vibrio sp. 
                    C.coli                                                                          V.parahaemolyticus 
             C.jejuni          Staphylococcus sp.    S.aureus                NAG Vibrio                  （halophilic）  Clostridium sp. 
                                                                                          V.cholerae 
                                             S.epidermidis            Listeria sp. 
                                                             L.monocytogenes 
               Campylobacter sp.                                                             C.perfringens             C.botulinum 
            Note 
            ：  Incubation time may be 24±2 hours depending on the food inspected. 
            ：  In this figure mentioned above, important kinds of bacteria for the food hygiene are listed, such as representative  
              bacteria related to ingredient standard and food poisoning in Japanese Food Sanitation Act. 
            ：  The figure mentioned above is a general concept, and, it is thought some cases does not apply because of the different    
              inspection procedure. 
              For example, in spite of "negative" for E.coli by inspection result, enterohemorrhagic E. coli O157 may not be "negative",    
              because of the different inspection procedure from E.coli and enterohemorrhagic E. coli O157. In addition, coliform  
              bacteria and E.coli according to Japanese Food Sanitation Act, ferment lactose in biochemical characteristic.  Nevertheless 
               some of the enterohemorrhagic E. coli strains do not ferment lactose. 
             ：  Some of the bacteria (such as genus Aeromonas) which do not belong to family Enterobacteriaceae, include the coliform  
              bacteria in Japanese Food Sanitation Act.  
             
                                                                                       TOHO Biological Laboratories Co.,Ltd.