Antimicrobial susceptibility of Clostridium perfringens strains isolated from broiler chickens / Sensibilidade antimicrobiana de estirpes de Clostridium perfringens isoladas de aves de corte

Clostridium perfringens is a normal inhabitant of the intestinal tract of chickens as well as a potential pathogen that causes necrotic enteritis and colangio hepatitis. The minimum inhibitory concentration (MIC) of seven different compounds used for therapy, growth promotion or prevention of coccidiosis was determined by agar dilution method for 55 C. perfringens strains isolated from the intestines of broiler chickens. All strains showed high susceptibility to penicillin, avilamycin, monensin and narasin. Only 7.3% of the strains showed an intermediated sensitivity to lincomycin, and 49 (89.1%) were considered susceptible. For tetracycline and bacitracin, 41.8% and 47.3% of strains, respectively, were considered resistant.

Clostridium perfringens é um habitante normal da microbiota intestinal de frangos, sendo um agente potencialmente patogênico, causador de enterite necrótica e colangio-hepatite.A concentração inibitória mínima (CIM) de sete drogas utilizadas na terapêutica, como agentes promotores de crescimento ou na prevenção de coccidiose foi determinada pelo método de diluição em ágar para 55 estirpes de C. perfringens isoladas do intestino de frangos de corte. Todas as estirpes revelaram alta sensibilidade à penicilina, avilamicina, narasin e monensina, apenas 7,3% demonstraram CIM intermediário para lincomicinae 89.1% foram consideradas sensíveis. Para tetraciclina e bacitracina, 41,8% e 47.3% das amostras, respectivamente, foram consideradas resistentes.

Evaluation of a Bacillus stearothermophilus tube test as a screening tool for anticoccidial residues in poultry

A Bacillus stearothermophilus var. calidolactis C953 tube test was evaluated for its ability in detecting the residue of selected anticoccidial drugs in poultry, specically sulfamethazine, furazolidone, and amprolium. Various concentrations of each drug were injected into chicken liver and kidney tissues and these tissues were tested to determine the drug detection limits for each drug. The detection limit was defined as the drug concentration at which 95% of the test results were interpreted as positive. The limits of detection in liver tissue were 0.35 microgram/ml for furazolidone, 0.70 microgram/ml for sulfamethazine and 7.80 microgram/ ml for amprolium. In kidney tissues, they were 0.30 microgram/ml for furazolidone, 0.54 microgram/ml for sulfamethazine, and 7.6 microgram/ml for amprolium. It was concluded that this tube test could be used to screen for the residue of these three drugs in poultry.