Genetic Background of Antimicrobial Resistance in Multiantimicrobial-Resistant Escherichia coli Isolates from Feces of Healthy Broiler Chickens in Tunisia

Table 3

Resistance genes detected by PCR assays in integron-positive and integron-negative E. coli isolates.

Antimicrobial agent (number of resistant isolates)	Genes detected in isolates (number of isolates):
	Integron positive ()	Integron negative ()
Sulfonamides (67)	sul1 (18)	sul1(5)
	sul2 (9)	sul2 (1)
	sul3 (1)	sul3 (1)
	sul1+sul2 (4)
	sul1+sul3 (3)
	sul2+sul3 (1)
	sul1+sul2+sul3 (1)
Tetracycline (78)	tetA (34)	tetA (19)
	tetB (6)	tetB (2)
	tetC (1)	tetA+tetB(1)
	tetA+tetB(5)