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

Abstract

BACKGROUND:The bacterial contamination of fertile eggs is<br />the most common cause of embryonic death in ostrich hatchery<br />units leading to financial loss in ostrich industry. OBJECTIVES:<br />The aim of this research was to investigate the bacterial<br />contamination status, with emphasis on Escherichia coli, of<br />ostrich hatcheries and the antimicrobial resistance profile of<br />isolated Escherichia coli. METHODS:Atotal of 120 ostrich eggs<br />with dead embryos, at weekly intervals, were collected from<br />three ostrich hatcheries. The dead embryos were sent to<br />laboratory and samples were collected aseptically from different<br />organs. Bacterial detection and identification were performed by<br />using standard bacteriological and biochemical techniques.<br />Antimicrobial susceptibility test was carried out by agar diskdiffusion<br />method against 27 antimicrobial agents. RESULTS:<br />Different types of bacteria were isolated from 56 eggs (46.7%).<br />Twenty-four ostrich eggs were shown to carry E. coli. In some<br />eggs, in addition to yolk sac, E. coli was also isolated from<br />meconium, liver, or heart blood which increased the total number<br />of E. coli isolates to 32. All E. coli isolates were susceptible to<br />trimethoprim + sulphamethoxazole, danofloxacin, and flumequine,<br />whereas all were resistant to carbenicillin and erythromycin.<br />Resistance to other agents was variable. Multi-drug<br />resistance pattern was found among all E. coli isolates and<br />included 2 to 12 drugs. Thirty-two E. coli isolates generated 30<br />different resistance profiles against 27 antimicrobial drugs.<br />CONCLUSIONS: This was the first comprehensive report<br />regarding the bacterial, particularly Escherichia coli, contamination<br />of dead-in-shell ostrich embryos and antimicrobial resistance<br />status of the Escherichia coli isolates from ostrich eggs in<br />Iran.