Abstract
Background: Bacterial infections causing digestive problems are among the most serious threats to Egypt's duck industry, owing to their effects on feed utilization and body weight gain.
Aim: As a result, the goal of this study was to identify bacterial pathogens causing enteritis in ducks as well as testing their antimicrobials resistance capabilities.
Methods: Forty-two duck flocks from different localities at four Egyptian Governorates (EL-Sharkia, El-Gharbia, El-Dakahlia and El-Qaliobia) have been subjected to clinical and postmortem examination as well as bacterial isolation and identification. The liver samples have been collected aseptically from freshly euthanized ducks for bacterial isolation followed by identification using conventional biochemical tests, VITEK 2 system and confirmatory PCR for detection of the uid A gene (beta-glucuronidase enzyme) of E. coli. In addition, antimicrobial sensitivity testing for the isolates against different antimicrobials by VITEK 2 system was used.
Results: Forty six positive bacterial isolates were identified using conventional methods and VITEK2 system including Staphylococcus spp. (52.17%), Escherichia coli (41.30%), and 2.17% for each of Enterococcus casseliflavus, Salmonella enterica subspecies arizonae and Enterobacter cloacae. PCR was positive for E. coli uid A gene at 556 bp. The antibiogram patterns of isolated pathogens from naturally infected ducks in our work demonstrated 100% multi drug resistance with varying results against different antimicrobial drugs tested. Such findings supported the fact of the upgrading multidrug-resistance of Staphylococci and Enterobacteriacae.
Conclusion: The most prevalent bacterial pathogens associated with duck enteritis were Staphylococcus spp. and E. coli with the first report of Salmonella enterica subspecies arizonae causing duck enteritis in Egypt.

Key words: Duck enteritis, Staphylococci, Salmonella, E. coli, Antimicrobials