Presumptive identification of sulphonamide and antibiotic residues in milk by microbial inhibitor tests

A new microbial screening method for the detection of antimicrobial residues in slaughter animals: The Nouws antibiotic test (NAT-screening)

“…Considering however the mentioned kidney/renal pelvis residue ratios, in practice this is not considered a problem. Using an indicator bacterium more sensitive for b-lactam antibiotics, for example Bacillus stearothermophilus, which is often used in screening methods for milk (Aureli, Ferrini, & Mannoni, 1996;Nouws et al, 1999;Gaudin et al, 2004) and commercially available methods like Premi Ò Test (DSM, Geleen, the Netherlands), is expected to yield considerably more false-positive results because of its vulnerability to naturally occurring growth inhibitors.…”

Microbial based assay for specific detection of β-lactam group of antibiotics in milk

“…The ampoules were further incubated at 30°C for 1 h for enzymatic action followed by addition of 20 μL of starch and varying concentration of iodine reagent. The time for color change β-Lactamase producing B.cereus was screened for MIC against sixteen antibiotics belonging to β-lactam, tetracycline, aminoglycosides, macrolides, sulphonamides, and miscellaneous groups based on zone of inhibition (IDF 1991;Aureli et al 1996). Ten mL agar medium containing 0.25% WP was poured in petridish pre-inoculated with vegetative cell pellet at the rate of 8 mL 100 mL −1 .…”

Aplicación de métodos microbiológicos en la detección de residuos de antimicrobianos en la leche de oveja.

“…Entre los métodos de cribado más utilizados en la detección de inhibidores en la leche cruda, se encuentran los métodos microbiológicos (Suhren, 1995;Reybroek, 1995;Korsrud et al, 1998) (Carlsson y Björck, 1987), Bacillus cereus Bacillus subtilis ATCC 6633 ( Aureli et al, 1995) y Streptococcus thermophilus (Mourot y Loussouron, 1981).…”

“…Dada la baja sensibilidad del microorganismo utilizado en todos los metodos anteriormente comentados, resulta interesante destacar los estudios realizados por Aureli et al (1996) al investigar la sensibilidad del Bacillus subtilis ATCC 6633 a la estreptomicina, ya que este microorganismo es capaz de detectar 125 µg/kg y aún obtienen una mayor sensiblidad (10 µg/kg) cuando incorporan cisteína al medio de cultivo, ambas concentraciones resultan inferiores a los 200 µg/kg establecidas por la UE como LMR.…”

“…Aureli et al (1996) cuando emplean Bacillus subtilis ATCC 6633, llegan a detectar 100 µg/kg de sulfadiazina en leche. Dichos autores establecen que la adición de ácido paraaminobenzoico disminuye el límite de deteción hasta 75 µg/kg.…”