Antimicrobial resistance in fecal Escherichia coli and Salmonella enterica isolates: a two-year prospective study of small poultry flocks in Ontario, Canada

Table 2 Most common antimicrobial resistance patterns of fecal Escherichia coli isolates from Ontario small poultry flocks, by poultry species

Poultry species	Antimicrobial resistance pattern^A	Number of antimicrobial classes in pattern (multidrug resistant)^B	n (%)^C
Chicken (N = 358)	STR-TET	2 (no)	19 (5.31)
	AMP-STR-TET	3 (yes)	22 (6.15)
	SSS-STR-TET	3 (yes)	6 (1.68)
	GEN-SSS-STR	2 (no)	6 (1.68)
	GEN-SSS-STR-TET	3 (yes)	5 (1.40)
	AMP-SSS-STR-STX-TET	4 (yes)	5 (1.40)
Turkey (N = 27)	AMP-TET	2 (no)	3 (11.11)
	STR-TET	2 (no)	2 (7.41)
	SSS-STR-TET	3 (yes)	2 (7.41)
	AMP-SSS-STR-STX-TET	4 (yes)	2 (7.41)
	AMP-CHL-CIP-NAL-SSS-STR-TET	6 (yes)	2 (7.41)
Duck (N = 24)	SSS-STX-TET	2 (no)	2 (8.33)
Game bird (N = 24)	STR-TET	2 (no)	6 (25.00)
Game bird (N = 24)	SSS-STR-TET	3 (yes)	2 (8.33)

^AResistance to 14 selected antimicrobials (including amoxicillin-clavulanic acid, ceftriaxone, cefoxitin, meropenem, azithromycin), as determined by a broth microdilution technique. GEN gentamicin, STR streptomycin, AMP ampicillin, SSS sulfisoxazole, STX trimethoprim-sulfamethoxazole, CHL chloramphenicol, CIP ciprofloxacin, NAL nalidixic acid, TET tetracycline
^BAn isolate was defined as multidrug resistant if it was non-susceptible to at least one antimicrobial in ≥3 antimicrobial classes (Aminoglycosides: GEN, STR; β-Lactams: AMP; Folate biosysnthesis pathway inhibitors: SSS, STX; Phenicols: CHL; Quinolones: CIP, NAL; Tetracyclines: TET)
^CNumber and percentage of isolates with each antimicrobial resistance pattern. For chicken, only patterns with ≥5 isolates are shown, and for other poultry species, only patterns with ≥2 isolates are shown

ISSN: 1746-6148