Abstract
Background:
Escherichia coli bacteria are normal flora in the digestive tract of animals and humans, while some E. coli isolates are pathogenic, causing disease in humans and animals. E. coli is one of the extended spectrum β-lactamase (ESBL) producing bacteria responsible for the increasing antibiotic resistance, ESBL is a β-lactamase enzyme that can hydrolyze penicillin, first, second, and third generation cephalosporins, and aztreonam.

Aim:
This study aimed to identify extended-spectrum β-lactamase (ESBL) producing E. coli bacteria in duck cloacal swab samples taken from seven live poultry markets in Surabaya.

Methods:
A total of 158 duck cloacal swab samples were obtained, isolated and identified with 85% (134/158) positive for E. coli bacteria using Mac Conkey Agar media, Gram staining, and then continued with biochemical tests Triple Sugar Iron Agar (TSIA), Methyl red (MR), Sulphide Indole Motility (SIM), Simmons Citrate Agar (SCA), and Voges-Proskauer (VP).

Results:
ESBL detection using a double disc synergy test (DDST) showed 60% (12/20) positive for ESBL. Confirmation of the polymerase chain reaction (PCR) test showed 58.3% (7/12) of samples were positive for blaTEM gene, with different percentages of positivity in each market.

Conclusion:
This study provides an important contribution in understanding E. coli as one of the ESBL-producing bacteria in poultry in live poultry markets, as well as the importance of monitoring and controlling the incidence of antibiotic resistance in food safety of animal origin.

Key words: Ducks, E. coli, blaTEM, ESBL, Public health