World shrimp production reached a record of 114.5 million tons of live weight in 2018, however, this issue is a concerned down to health on shrimp’s health. Strains of Vibrio spp. continued as an important pathogen for the penaeid shrimp causing illness and mortality (i.e. hepatopancreatic necrosis syndrome). Disinfection had been a tool for prevent and control these bacterial diseases. Combination of quaternary ammonium salts (QAC) and glutaraldehyde (GLU) are two of the most widely used disinfectants on shrimp’s ponds to maintain low overgrowth of Vibrio spp. This study evaluated the sanitizing effectiveness of an applied QAC-GLU combination on water ponds by adopting an attribute sampling and analytical criteria.
The study was done in a shrimp fattening farm located at the south of Sonora (25 ponds distributed in 75 ha with common estuary). During June to August 2021, all ponds were treated with a commercial QAC-GLU (Pecdesin® 4G) applying 1 liter/ha3 (23 ppm) as previously recommended1,2,3, then, three ponds were selected for analysis through 20 water samples per pond (100 mL). In addition, hepatopancreas from 15 shrimp were sampled in Whirl-Pak® bags; both samples were collected twice at 0 and 48 h post treatment for pH, salinity, QAC residual and counting of native Vibrio spp (green and yellow ones). Bacterial counts were converted to log10 and then adjusted to a score scale (0 to 5+) while only physicochemical values were adjusted to score scale (0 to 5+). The analytical criteria method considered as satisfactory (for overgrowth control) if more than 90% samples achieve up to 2.0+ and 3.0+ bacterial load grade on both water and hepatopancreas, respectively, as well as satisfactory (for product application) if more than 50% samples achieve up to 1.0+ QAC score scale on water. A comparison between consecutive cycles were done to analyze productive performance using the sanitization mentioned. Graph 1 and 2 shows the mean count as bars (CFU/ml) and bacterial load grade as slope (BLG) obtained in water (w) and hepatopancreas (hp).