Bacterial contamination of dead-in-shell embryos in ostrich hatcheries and antimicrobial resistance patterns of isolated Escherichia coli

BACKGROUND:The bacterial contamination of fertile eggs isthe most common cause of embryonic death in ostrich hatcheryunits leading to financial loss in ostrich industry. OBJECTIVES:The aim of this research was to investigate the bacterialcontamination status, with emphasis on Escherichia coli, ofostrich hatcheries and the antimicrobial resistance profile ofisolated Escherichia coli. METHODS:Atotal of 120 ostrich eggswith dead embryos, at weekly intervals, were collected fromthree ostrich hatcheries. The dead embryos were sent tolaboratory and samples were collected aseptically from differentorgans. Bacterial detection and identification were performed byusing standard bacteriological and biochemical techniques.Antimicrobial susceptibility test was carried out by agar diskdiffusionmethod against 27 antimicrobial agents. RESULTS:Different types of bacteria were isolated from 56 eggs (46.7%).Twenty-four ostrich eggs were shown to carry E. coli. In someeggs, in addition to yolk sac, E. coli was also isolated frommeconium, liver, or heart blood which increased the total numberof E. coli isolates to 32. All E. coli isolates were susceptible totrimethoprim + sulphamethoxazole, danofloxacin, and flumequine,whereas all were resistant to carbenicillin and erythromycin.Resistance to other agents was variable. Multi-drugresistance pattern was found among all E. coli isolates andincluded 2 to 12 drugs. Thirty-two E. coli isolates generated 30different resistance profiles against 27 antimicrobial drugs.CONCLUSIONS: This was the first comprehensive reportregarding the bacterial, particularly Escherichia coli, contaminationof dead-in-shell ostrich embryos and antimicrobial resistancestatus of the Escherichia coli isolates from ostrich eggs inIran.