The MBS Microbial Rapid Detection System for rapid detection of major pathogenic bacteria in feed: Comparison with plate counting method

The current methods for detecting pathogenic bacteria in feed require high technique and take a long time. A Micro Biological Survey (MBS) rapid detection system is a simple, economical and rapid microbial detection method. The purpose of this experiment was to compare the detection of Escherichia coli ( E. coli ), Salmonella , Staphylococcus aureus ( S. aureus ), Listeria monocytogenes (LM), coliform (COLI) and total viable count (TVC) in feed by the MBS rapid microbial detection system and plate counting method (PCM). The results showed that the MBS microbial rapid detection system could detect E. coli, Salmonella, S. aureus , LM, COLI and TVC in artificially contaminated sterilized fish meal, and the quantitative limit were 5.58 cfu/mL, 8.60 cfu/mL, 7.90 cfu/mL, 8.40 cfu/mL, 3.93 cfu/mL and 7.43 cfu/mL, respectively. The quantitative limit of the PCM were 41.30 cfu/mL, 56.70 cfu/mL, 39.00 cfu/mL, 56.00 cfu/mL, 40.00 cfu/mL and 48.00 cfu/mL, respectively. The recovery rates of the MBS microbial rapid detection system for E. coli, Salmonella, S. aureus , LM, COLI and TVC in the concentration range of 10 1 ~10 8 cfu/mL were 87.92 ~ 98.42%, 87.19 ~ 90.76%, 89.95 ~ 96.32%, 89.15 ~ 92.93%, 90.95 ~ 97.66% and 90.21 ~ 97.03%, respectively; the recovery rates of the PCM were 5.58%~92.60%, 79.77%~93.48%, 86.33%~94.01%, 83.05%~92.69%, 87.44%~96.58% and 87.09%~94.98%, respectively. The coefficients of variation of the MBS microbial rapid detection system for detecting E. coli, Salmonella, S. aureus , LM, COLI and TVC in sterilized fish meal were 9.83%, 7.18%, 10.28%, 9.55%, 8.03% and 9.21%, respectively. The coefficients of variation of PCM were 14.92%, 13.84%, 15.63%, 12.18%, 13.21% and 14.91%, respectively. When detecting the pathogenic bacteria content in artificially contaminated feed, the MBS rapid microbial detection system was positively correlated with the PCM. When the MBS microbial rapid detection system and PCM were used to detect the collected real feed samples, there was no significant difference in the detection results of the two methods in most of the feed samples. In summary, the quantitative limit, recovery rate and coefficient of variation of the MBS microbial rapid detection system are better than the quantitative limit, recovery rate and coefficient of variation of the plate counting method, which is the most convenient and rapid detection method and is suitable for promotion and application in production lines.