Antibacterial and antibiofilm effect of nano zinc-oxide and propolis nanoemulsion against strong biofilm producer coliform species isolated from chickens

Abstract

A total of 150 samples collected from freshly dead chickens were examined for Coliform bacteria. The results revealed isolation of 141 isolates (84 E. coli (56%), 6 Klebsiella pneumoniae (4%), 10 Klebsiella oxytoca (6.6%), 17 Klebsiella ozanae (11.3%), and 24 Citrobacter freundii (16%)). Strong biofilms on Congo red agar were produced by 37 E. coli isolates (44%), 3 Klebsiella pneumoniae (50%), 5 Klebsiella oxytoca (50%), 7 Klebsiella ozanae (41%) and 10 Citrobacter freundii (41%). Antimicrobial susceptibility test on strong biofilm producer isolates revealed that all isolates exhibited high resistance to Amoxicillin, Oxytetracycline and Erythromycin, Trimethoprim Sulfamethoxazole, while their sensitivity to gentamicin was high. Strong biofilm E. coli isolates were serotyped to O91: