Pseudomonas spp are considered a common milk-associated psychotropic bacteria, leading to milk deterioration during storage;
therefore, our study aimed to study the distribution of Pseudomonas aeruginosa in raw milk and its associated products
then studying the growth behavior of P. aeruginosa in milk after employing chitosan nanoparticles (CsNPs 50, 25, and 15
mg/100ml) and selenium nanoparticles (SeNPs 0.5, 0.3 and 0.1 mg/100ml) as a trial to control the bacterial growth in milk
during five days of cooling storage. Our study relies on the ion gelation method and green synthesis for the conversion of
chitosan and selenium to nanosized particles respectively, we subsequently confirmed their shape using SEM and TEM. We
employing Pseudomonas selective agar medium for monitoring the bacterial growth along the cooling storage. Our findings
reported that high prevalence of Pseudomonas spp count in raw milk and kareish cheese and high incidence percent of P.
aeruginosa in ice cream and yogurt respectively. Both synthesized nanoparticles exhibited antibacterial activity in a dosedependent
manner. Moreover, CsNPs50 could inhibit the P. aeruginosa survival growth to a mean average of 2.62 ± 1.18
log10cfu/
ml in the fifth day of milk cooling storage; also, it was noted that the hexagonal particles SeNPs0.5 could inhibit
2.49 ± 11 log10cfu/
ml in comparison to the control P. aeruginosa milk group exhibited growth survival rate 7.24 ± 2.57
log10cfu/
ml under the same conditions. In conclusion, we suggest employing chitosan and selenium nanoparticles to improve
milk safety and recommend future studies for the fate of nanoparticles in milk.