Aerosolic Application of Phages Against S. infantis on Plates and Chicken Skin

Abstract

Phages are known as a promising method to combat antimicrobial resistance (AMR) in the human and veterinary sector. Use of phage aerosols enormously increases the application field, although the impact on the infectivity of phages during nebulization needs to be evaluated. In this study S. infantis was treated on plates and chicken skin with nebulized phage particles of the Myoviridae type, identified by transmission electron microscopy, using a commercial nebulizer primarily used for H₂O₂ disinfection. The reduction of bacterial number by aerosol applied phage particles was evaluated. It could clearly be shown that the phage particles were able to infect Salmonella after being nebulized using ultrasound technology. Further studies on other types of phages as well as other conditions must be performed to standardize the aerosolic application of phages.

Keywords: AMR; Myoviridae; S. infantis; aerosol; nebulization.

FIG. 1.

A. Reduction of CFU/mL (Colony Forming Units) of S. infantis colony after phage nebulization. (P) represents the LB agar plate matrix, whereas (skin) are the chicken skin samples (1 cm × 1 cm). Only bacteria colonies from 10 to 300 were counted, so threshold of maximum of 300 colonies were set. E1 – Experiment 1 displayed fully eradication of bacteria on both plates and skin samples, while the mean of E2 and E3 showed quantitative reduction by 10^–3 dilution. B. Reduction of S. infantis after treatment with collected nebulized phage particles, which show a reduction of bacteria, and additionally with H₂O₂ nebulized phage particles, which lead to phage inactivation and growth of S. infantis.

FIG. 2.

S. infantis phage of the Myoviridae family by using transmission electron microsocopy (TEM) before nebulization for characterization.