ABSTRACT
The postantibiotic effects (PAEs) and postantibiotic sub-MIC effects (PA SMEs) of tilmicosin, erythromycin and tiamulin on erythromycin-susceptible and erythromycin-resistant strains of Streptococcus suis (M phenotype) were investigated in vitro. Tilmicosin and tiamulin induced significantly longer PAE and PA SME against both erythromycin-susceptible and erythromycin-resistant strains than did erythromycin. The durations of PAE and PA SMEs were proportional to the concentrations of drugs used for exposure. The PA SMEs were substantially longer than PAEs on S. suis (P<0.05) regardless of the antimicrobial used for exposure. The results indicated that the PAE and PA SME could help in the design of efficient control strategies for infection especially caused by erythromycin-resistant S. suis and that they may provide additional valuable information for the rational drug use in clinical practice.
Subject(s)
Animals , Anti-Bacterial Agents/analysis , Anti-Bacterial Agents/adverse effects , Disease Susceptibility , Drug Resistance, Microbial , In Vitro Techniques , Streptococcal Infections , Swine , Streptococcus suis/growth & development , Streptococcus suis , Streptococcus suis/genetics , Streptococcus suis/isolation & purification , Culture Media , Methods , Phenotype , Polymerase Chain Reaction/methods , Sampling Studies , MethodsABSTRACT
Las espiroquetas intestinales del género Brachyspira ocasionan enfermedades importantes en porcinos y aves. Se ha evidenciado un problema de incremento en la presentación de cepas resistentes a los antimicrobianos utilizados normalmente para tratar las espiroquetosis intestinales en porcinos, y esto podría ser aplicable a los aislamientos de aves. Hay muypocos reportes de sensibilidad antimicrobiana in vitro de cepas de Brachyspira spp. aisladas en aves. En este estudio se evaluó la sensibilidad de doce aislamientos de Brachyspira pilosicoli obtenidos de granjas de ponedoras comerciales a los agentes antimicrobianos tiamulina, tilosina y lincomicina, y se estableció la concentración mínima inhibitoria (CMI)mediante la técnica de dilución en agar. Todas las bacterias analizadas fueron sensibles a tiamulina (CMI≤0,1 μg/ml) y lincomicina (CMI 1 μg/ml) y resistentes a tilosina (CMI 5 μg/ml).
Intestinal Spirochaetes of the genus Brachyspira cause important diseases in swine and poultry. An increasing problem in the presentation of resistant strains to the antimicrobial drugs usually used to treat the intestinal spirochaetosis in swine has been evidenced and this could be applicable to the isolations from poultry. There are very few reports of in vitro antimicrobialsusceptibility of Brachyspira spp. isolated from birds. In this study the antimicrobial susceptibility of twelve Brachyspira pilosicoli isolates obtain from commercial layers was evaluated against tiamulin, tylosin and lincomycin establishing the Minimum Inhibitory Concentration (MIC) by agar dilution technique. All bacteria analyzed were sensitive to tiamulin (MIC ≤0,1μg/ml), and lincomycin (MIC 1μg/ml) and resistant to tylosin (MIC 5μg/ml).