Reference | Miranda2008a (10060)

A total of 108 healthy male “label” chickens aged 4 to 6 wk obtained from the same commercial hatchery were used. The chickens were fed with the same antimicrobialfree feed before starting antimicrobial treatment. These chickens were split into 3 groups of 36 animals per group. In each of these 3 groups, 18 broilers were treated with a therapeutic antimicrobial dosage and another 18 were maintained as controls. Eighteen chickens were weighed and treated with a therapeutic dose of enrofloxacin in water (0.05 g/L) of Colmyc-E (S.P. Veterinaria, Tarragona, Spain), and another 18 were weighed and kept untreated as controls. The treatment was administered over 5 d, keeping a period of 12 d as the withdrawal time. Each group of chickens was sampled immediately before starting treatment (d 0), on the first day of treatment (d 1), in the middle of treatment (d 3), on the last day of treatment (d 5), in the middle of the withdrawal period (d 11), and after the withdrawal time had ended (d 17). Eighteen chickens were weighed and treated with a therapeutic dose of doxycycline in water (1 g/L) of Doxidol (Fatro Uriach Veterinaria, Barcelona, Spain), and another 18 were weighed and kept as controls. The treatment was administered over 5 d, keeping a period of 7 d as the withdrawal time, in accordance with the manufacturer’s instructions. Each group of chickens was sampled immediately before starting treatment (d 0), on the first day of treatment (d 1), in the middle of treatment (d 3), on the last day of treatment (d 5), in the middle of the withdrawal period (d 8), and after the withdrawal time had ended (d 12). Eighteen chickens were weighed and treated with a therapeutic dose of a sulfonamides mixture (1.33 g of Sulfaquinoxaline + 1.66 g of Sulfamethazine + 1.66 g of Sulfameracine + 3.33 g of Sulfisoxazole/100 mL) in water (15 mL/L) from Cunisan Aviar (Arimany, Barcelona, Spain), and another 18 were weighed and kept as controls. The treatment was administered over 4 d, followed by 2 d of repose and another 3 d of treatment, in accordance with the instructions on the package insert. After treatment, a withdrawal period of 15 d was kept. Each group of chickens was sampled immediately before starting treatment (d 0), on the first day on treatment (d 1), on the fourth day of treatment (d 4), on the last day of treatment (d 9), in the middle of the withdrawal period (d 16), and after the withdrawal time had ended (d 24).

For the 3 antimicrobials tested, fecal samples were taken by swabbing the cloacae of each chicken with sterile swabs to obtain a minimum of 0.5 g of fecal matter

AST Method: Broth Microdilution

Reference explicitly reports AST breakpoints: True

Reference reports using a MIC table: True