ATP bioluminescence used to assess trailer cleanliness
Prairie Swine Centre research publishes a new study documenting the successful use of ATP bioluminescence in efficiently testing trailer hygiene
12 October 2018
3 minute read
By: Authors BZ Predicala, AC Alvarado, and J Cabahug
Abstract
Proper washing and disinfection of swine transport trailers is an important step in maintaining biosecurity. One specific study examined the feasibility of using adenosine triphosphate (ATP) bioluminescence as a rapid and effective swine trailer cleanliness assessment tool. Samples were taken from newly-cleaned, dry trailers using an ATP swab by swabbing an area of 10 cm x 10 cm and were tested for microbial contamination level using an ATP bioluminescence meter.
The results obtained from ATP testing were compared to the co-located samples taken using standard microbiological techniques with MacConkey and R2A agar contact plates (diameter Ø = 60 mm).
From a total of more than 500 samples collected from 16 commercial swine transport trailers across Saskatchewan, a significant correlation (r = 0.206; p=0.001) was found between ATP bioluminescence method and standard microbiological technique using R2A agar plates.
Lower correlation (r = 0.154; p=0.002) was observed between ATP method and MacConkey agar plate counts. Unlike R2A that detects a wider group of bacteria, MacConkey agar supports only the growth of selected gram-negative bacteria while ATP bioluminescence detects ATP from both microbial and organic sources.
Assessing the effectiveness of swine transport trailer cleaning protocol using ATP bioluminescence method threshold values were established with readings of less than 430 RLU per 100 cm2 as ‘Pass’ while higher than 850 RLU per 100 cm2 as ‘Fail’ or has high risk of disease propagation.
Conclusions
• ATP bioluminescence method can be used as a tool for rapid assessment of surface cleanliness of swine transport trailers, complementing the procedures specified in CSHB (2011). Dirty areas in trailers can be rapidly identified using ATP method hence, corrective actions on the current washing/disinfection protocol can be made.
• ATP method had moderate correlation with the standard microbiological method using R2A agar plates; no readily apparent relationship was observed between ATP method and MacConkey agar (MCA) plate counts.
• Results from this study have confirmed that visual inspection of newly cleaned transport trailers is not sufficient in assessing its surface cleanliness because significant levels of ATP and microbial loads were detected on trailer surfaces after cleaning.
• Regardless of the method of assessment used, trailer floors posed the highest risk of microbial contamination among all the six critical areas tested.
