Enterobacteriaceae threaten the success of the poultry industry, as they cause great economic losses due
to the high mortalities and the high treatment cost. They cause serious public health hazards, as they are the major
cause of food-borne infections. The study aimed to investigate the prevalence of Enterobacteriaceae in twelve poultry
farms located in Qalubia Governorate, Egypt, and their antimicrobial resistance. A total number of 2160 samples
included litter, pen litter, stored feed, feed from the feeders, water, drinkers, droppings, dust, swabs from walls, birds’
cloaca, worker’s hands, and wheels of vehicles. The results showed that there was a negative relationship between the
prevalence of Enterobacteriaceae and the hygienic measures enforced in the poultry farms under study. The highest
prevalence of Salmonella and E. coli was recorded in duck farms (36.2% and 54.3% respectively) and the lowest prevalence was recorded in breeder chicken farms (10.2% and 29.3% respectively). The isolated Salmonella species showed
high resistance (100%) against doxycycline, ampicillin, and amoxicillin, while E. coli species showed resistance (90%)
against oxytetracycline, doxycycline, ampicillin, and amoxicillin. Both Salmonella and E. coli species were highly susceptible to gentamicin. Gene tetA and blaSHV were detected in Gene tetA and blaSHV were detected in 28.5% &
57.1% of Salmonella, respectively, and 70% & 60% of E. coli serotypes, respectively. The application of good biosecurity
programs including strict measures in poultry farms is the preferable method to reduce the risk of pathogenic bacteria
and reduce the use of antibiotics.