This study was conducted on 88 broiler chicks from one day to five days. They were collected from
three hatcheries at two governorates to detect the prevalence of infection by Aspergillus spp and/or E.
coli serotypes. This study revealed that the prevalence was 35.2%,43.2% and 18.2%for E. coli
serotypes, Aspergillus spp and both infection together, respectively. The clinical signs of the examined
broiler chicks appeared as weakness, respiratory manifestation (gasping) and diarrhea. The postmortem
lesions were mainly on lungs and air sacs which appeared congestion, white nodules in lungs and
yellowish white cheesy materials on air sacs and lungs. Some chicks showed signs of enteritis.
Bacteriological and mycological examinations for collected broiler chicks revealed that E. coli O125
and Aspergillus fumigatus were the most common isolates. Experimental infection of 124 one-day old
broiler chicks which checked and confirmed to be free from both infectious agents with inoculation of
E. coli O125 (intranasal/ one dose) and/or Aspergillus fumigatus (intra air sacs/one dose) showed
weakness, respiratory manifestation(gasping), diarrhea, congested lungs and cheesy materials on lungs
and air sacs. Reisolation and identification revealed positive results for infectious agents.
Histopathological examination was also described. Concerning to growth performance and mortality
rate, dual infection showed much decrease in weight and increase in mortality rate than single infection.
In conclusion the dual infection has more pathogenic effect than single infection.