Effect of thymol on planktonic and biofilm cells in drinking water: An anti-cryptosporidium effect

There is a consensus that biofilm shows resistance to antimicrobial agents, especially in poultry farming. The current study assesses how thymol's antiparasitic properties affect the load of parasites, particularly Cryptosporidium oocysts load, in chicken drinking water. The first experiment used microscopic counting to evaluate in vitro the anti-cryptosporidium activity of NPEB (a thymol-based product) on drinking water samples. Thymol was added to samples in increasing doses (1, 2, and 4 g L-1 of NPEB). The anti-cryptosporidium efficacy in vitro was dose-dependent (p < 0.05, p < 0.01, and p < 0.001). Moreover, the antibiofilm efficiency of the thymol-based product against protozoan biofilm (Cryptosporidium oocysts) was tested using an experimental arrangement simulating the water supply system in poultry farming. In order to do that, we conducted two preventive and curative tests utilizing two distinct product concentrations (1 and 2 g L-1). A greater reduction was shown for the concentration 2 g L-1, which is in the order of three logarithmic units. The removed water from treated pipes with thymol (1 g L-1 of the product) showed a significant decrease (p < 0.05) in the curative study as compared to controls. However, after just 24 hours of treatment, the amount of 2 g L-1 treated pipes was significantly reduced (p < 0.01).