Antimicrobial potential of essential oils and blue-green Algae against E. coli isolated from diseased broiler

Abstract

 Enterobacteriaceae have a significant importance as an infectious agent of chickens causing substantial morbidity and mortality in addition to economic losses. In the present work, the prevalence of Enterobacteriaceae was investigated in many broiler chickens farms in Beni-Suef Governorate. One hundred and seventeen samples were obtained aseptically from the affected organs including heart, liver, yolk sac, air sac and pericardium of diseased and recently dead broilers. Collected samples underwent bacteriological investigation, which revealed that 95 isolates were isolated with a percentage of 81.2% including 90 E. coli isolates (76.9%) and 5 Proteus species (4.3%). In-vitro antimicrobial sensitivity test results indicated that E. coli isolates exhibited complete resistance against ciprofloxacin (100%), reduced resistance against enrofloxacin (82%), chloramphenicol (76%), streptomycin (74%), cefotaxime (60%), sulfamethoxazole-trimethoprim and ceftazidime (46% for each), while showed high susceptibility to amikacin (92%), fosfomycin (76%), doxycycline (74%), amoxicillin-clavulanic acid (70%), ertapenem (66%) and colistin (60%). Moreover, multi-drug resistance was determined in 78% of tested isolates. The antibacterial effect of some essential oils (clove, cinnamon, oregano and eucalyptus oil) and blue green algae was evaluated against the growth of MDR E. coli isolates and the results revealed that clove, cinnamon and oregano EOs completely inhibited the growth of all examined E. coli isolates (100%) at concentrations of 1000 ppm, 500 ppm and 250 ppm, respectively. Whereas eucalyptus EO showed no bactericidal effect on all tested E. coli isolates at concentrations up to 1500 ppm. Moreover, blue green algae showed no bactericidal effect on all tested E. coli isolates at concentrations up to 10%. Finally, molecular characterization of resistance and virulence genes declared that all isolates carried blaTEM, sul1, fimH, iss and iutA (100%), while qnrS was detected in 60% of tested isolates.