Photohydroionisation for disinfection of poultry litter.

ABSTRACT

1. This study evaluated photohydroionisation efficiency on the disinfection of new shavings used as substrate for litter in the poultry industry, pre-inoculated with bacterial, fungal and viral agents.2. Each replicate consisted of 250 g of new shavings sterilised by autoclaving, challenged with bacterial (Escherichia coli, Staphylococcus aureus, and Salmonella enterica, serovar Abony), fungal (Saccharomyces cerevisiae) and viral inoculum (Gumboro disease virus). The experiment consisted of six replicates at four times (0, 1, 5 or 10 min exposure) of photohydroionisation. The disinfection process was performed in a bench photohydroionisation device with four ultraviolet lamps. The agents inoculated in the shavings were analysed after the disinfection process.3. The counts of enterobacteria and total bacteria showed a quadratic effect. In contrast, the counts of fungi and viruses showed a negative linear effect with an increase in the time of photohydroionisation. The enterobacteria showed a linear response plateau effect (LRP), with a minimum time point of 5.498 minutes at a minimum contamination of 0.666 CFU/g and a reduction of 82.27% of the pre-established inoculum. Total bacteria had an LRP effect with a minimum time point of 1.902 minutes at minimum contamination of 1.739 CFU/g and a reduction of 50.0% of the pre-established inoculum. An LRP effect was found for fungi, with a minimum time point of 7.931 minutes in minimum contamination of 3.380 CFU/g, and with a reduction of 11.0% of the pre-established inoculum. For viruses, there was an LRP effect with a minimum time point of 5.012 minutes in minimum contamination of 0.000 viral titre per 100 g of shavings, which was reduced by 100% of the pre-established inoculum.4. Photohydroionisation in the disinfection of new shavings used as poultry litter has partial potential as a microbiological control tool, as a complete reduction occurred only for the viruses, whereas for bacteria and fungi only partial reductions of these microorganisms were observed.