A microtiter plate method to optimize the concentration and exposure time of potassium permanganate (KMnO4) for disinfecting fishing nets
摘要
Fishing nets are potential vehicles for both inter- and intra-farm transmission of microorganisms, so, disinfecting them with potassium permanganate (KMnO4) is an important biosecurity measure to prevent disease transmission. However, the evaluation of KMnO4 concentrations and exposure time is vital for effective disinfection procedure. A method was developed that employs a 96-well microtiter plate to test five different concentrations of KMnO4 (10 ppm, 20 ppm, 30 ppm, 50 ppm and 100 ppm) over five exposure time periods (1 min, 5 min, 10 min, 20 min and 30 min). Nylon threads used in fishing nets were sterilized, soaked in sterile seawater spiked with either a single bacterial species (Vibrio parahaemolyticus, ATCC 17802), or cocktail of bacteria (either cocktail of 20 V. parahaemolyticus isolated from white faeces syndrome affected Penaeus vannamei shrimp or a cocktail of 20 antimicrobial resistant (AMR) E. coli), and treated with different concentrations of KMnO4 for different times. The results indicated that treatment of nets with 30 ppm KMnO4 for 1 min was effective in controlling the growth and survivability of V. parahaemolyticus and AMR E. coli. Of interest, the nylon threads exposed to 30 ppm KMnO4 treatment did not reveal any textural damage to the net material. To sum up, disinfection of fishing nets with KMnO4 at conditions optimized by employing the microtiter plate method helps in preventing the spread of bacterial pathogens and antimicrobial resistant bacteria in aquaculture.