Effect of tunable femtosecond laser pulses on the sporulation of Eimeria species oocysts of chickens: An in vitro study

Abstract

Parasitic Eimeria species infection is a severe disease in the poultry industry and a major cause of coccidiosis and disease-engendered financial losses. Increasing resistance to drug-based treatment presents a significant problem, as does the use of disinfectants to sanitize poultry farms, because of increasing oocyst resistance to chemical interventions and contamination of poultry products. Reducing the rate of sporulation of Eimeria species oocysts can minimize the spread of the disease. Therefore, we studied the effect of femtosecond laser pulses on oocysts sporulation rate with the goal of developing an effective light-based treatment for coccidiosis, as an alternative to pharmaceutical intervention. Eimeria species oocysts were harvested from the intestines of infected broiler chickens. Unsporulated oocysts obtained were distributed over 96 well plates and irradiated with pulsed femtosecond laser at various wavelengths and exposure times. Irradiation of the oocysts with pulsed 360 to 390 nm femtosecond laser significantly reduced their sporulation rate and altered their morphology compared to untreated controls. Compared to other wavelengths within the 360 to 390 nm spectra, treatment with pulsed 370 nm wavelength was most effective in decreasing oocyst sporulation rate, reducing sporulation to 17%, 15%, and 11%, after 5-, 10-, and 15-min exposure times, respectively. In contrast, irradiation with infrared 720 nm and 800 nm wavelengths had no significant effect on oocysts sporulation rate. These findings clearly show that irradiation with a pulsed 370 nm femtosecond laser effectively reduces Eimeria species oocyst sporulation and that it is possible to develop an effective light-based treatment for coccidiosis.