ABSTRACT
The bacterial contamination of fertile eggs is the most common cause of embryonic death in ostrich hatchery units leading to financial loss in ostrich industry. The aim of this research was to investigate the bacterial contamination status, with emphasis on Escherichia coli, of ostrich hatcheries and the antimicrobial resistance profile of isolated Escherichia coli. A total of 120 ostrich eggs with dead embryos, at weekly intervals, were collected from three ostrich hatcheries. The dead embryos were sent to laboratory and samples were collected aseptically from different organs. Bacterial detection and identification were performed by using standard bacteriological and biochemical techniques. Antimicrobial susceptibility test was carried out by agar disk diffusion method against 27 antimicrobial agents. Different types of bacteria were isolated from 56 eggs [46.7%]. Twenty-four ostrich eggs were shown to carry E. coli. In some eggs, in addition to yolk sac, E. coli was also isolated from meconium, liver, or heart blood which increased the total number of E. coli isolates to 32. All E. coli isolates were susceptible to trimethoprim + sulphamethoxazole, danofloxacin, and flumequine, whereas all were resistant to carbenicillin and erythromycin. Resistance to other agents was variable. Multi-drug resistance pattern was found among all E. coli isolates and included 2 to 12 drugs. Thirty-two E. coli isolates generated 30 different resistance profiles against 27 antimicrobial drugs. This was the first comprehensive report regarding the bacterial, particularly Escherichia coli, contamination of dead-in-shell ostrich embryos and antimicrobial resistance status of the Escherichia coli isolates from ostrich eggs in Iran
ABSTRACT
Colibacillosis is one of the most economically important diseases of poultry worldwide. This study was conducted to examine the clonal relatedness and typing of 95 avian Escherichia coli isolates by ERIC-PCR.. Sixty-three E. coli isolates from two common manifestations of colibacillosis [yolk sac infection and colisepticemia] and 32 isolates from feces of apparently healthy broilers were provided. The PCR amplification reactions were performed in duplicate for all isolates. The molecular weight of the observed bands on gel electrophoresis ranged from 232 bp to 2690 bp. Sixty-five fingerprinting patterns were observed among 95 isolates on the basis of molecular weights and the number of bands. The numbers of 20, 22, and 23 fingerprinting patterns were found among isolates from yolk sac infection, colisepticemia, and feces, respectively. Among different fingerprinting patterns, the number of produced bands differed from 2 to 11. No identical pattern was observed among isolates of three sources. Isolates showing similar patterns in each source group belonged to a single farm. However, a few isolates that had been isolated from different farms also showed similar fingerprinting patterns. In conclusion, this study showed a high degree of polymorphism among E. coli isolates originated from different poultry sources when the respective bacterial genomes were analyzed by the ERIC-PCR and that no specific genotypes were responsible for different manifestations of colibacillosis
ABSTRACT
Infectious bursal disease [IBD] is one of the most important viral poultry diseases. To prevent the disease it is required that there be maternal and active immunity prior to and after three weeks of age. Live vaccines are usually used to immunize the broiler flocks. In addition to the type of vaccine, the route of vaccination, also, has effects on mounting an immune response. In this study, we administered a single dose vaccination of an intermediate IBD vaccine strain at 21 days of age via five routes including subcutaneous [SC], intramuscular [IM], drinking water, eye drop, and course spray. The impact of the vaccination route on mounting antibody response was evaluated by a commercial ELISA kit [IDEXX]. Antibody response was mounted by all routes. The highest antibody titer in the last two sampling turns belonged to birds in the group vaccinated by the SC route, but this difference was not statistically significant [p>0.05] when compared to those of other vaccinated groups. In addition to the highest antibody titer, the highest bursal/body weight ratio and body weight were observed in birds of the SC-vaccinated group. It was found that the groups vaccinated by injection, SC or IM, were the only groups that achieved to a protective level of antibody titer in the last turn of sampling. It was concluded that a single dose injection of an intermediate IBD vaccine, via SC route, is able to induce higher antibody response, and improve bursal health and performance of chickens as compared with those vaccinated via drinking water