Suitability of the charm HVS and a microbiological multiplate system for detection of residues in raw milk at EU maximum residue levels

Abstract

(1999) Suitability of the charm HVS and a microbiological multiplate system for detection of residues in raw milk at EU maximum residue levels, Veterinary Quarterly, 21:1, 21-27, DOI: 10.1080DOI: 10. /01652176.1999 Accepted for publication: October 13, 1998 SUMMARY In this paper we assessed the suitability of the Charm HVS and a newly developed microbiological multiplate system as post-screening tests to confirm the presence of residues in raw milk at or near the maximum permissible residue level (MRL). The multiplate system is composed of Bacillus stearothermophilus var. calidolactis plate at pH 8.0 for detection of beta-lactam antibiotics and tylosin, Bacillus cereus plate at pH 6.0 for detection of tetracyclines, Micrococcus luteus plate at pH 8.0 for detection of macrolides, Bacillus subtilis BGA plate at pH 8.0 for detection of aminoglycosides, trimethoprim-containing plate seeded with B. subtilis BGA at pH 7.0 for detection of sulphonamides, Escherichia coli plate at pH 6.0 for detection of quinolone and polymyxin, and Staphylococcus epidermidis plate at pH 6.0 for detection of novobiocin. For each test plate an action level is proposed in such a way that residues can be detected in raw bulk tank milk at levels near or below the established EU MRLs of beta-lactam antibiotics, tetracyclines, aminoglycosides, macrolides, sulphonamides, colistin, and quinolones. The Charm HVS test used to confirm the presence of tetracycline and macrolide residues gave false-positive results near the EU MRLs. The multiplate system gave valid results. Based on data for raw bulk tank milk samples and the proposed action level for each test plate for suspected samples, we demonstrated that the multiplate system is a reliable postscreening method that can be performed easily and cheaply in microbiological laboratories.

A plate diffusion method for detecting fluoroquinolone residues in raw cow's milk

“…These methods use various strains of E. coli and substrates of various pH, e.g. E. coli Bayer 14 at pH 6 (Okerman et al 2001), E. coli RIK 144 at pH 6 (Nouws et al 1999b), E. coli ATCC 11303 at pH 7.2 (Myllyniemi et al 2001) and/or at pH 8 (Gaudin et al 2004). According to Choi et al (1999), the E. coli strain ATCC 128 was highly suitable as an indicator of microorganisms in a microbial inhibition test for selective detection of fluoroquinolone residues in animal tissues.…”

“…This method did not display sufficient sensitivity to FLU or colistin. Nouws et al (1999b) evaluated the suitability for confirmation of the presence of antibiotic residues in milk. The estimated detection levels of the method with E. coli (RIK 144, pH 6) for ENRO, FLU and colistin were < 10, 150, and 100 µg/l, respectively.…”

Evaluation of the Bacillus calidolactis plate for post screening assay of β-lactam antimicrobial residues in Kenyan dairies

“…It might thus be useful for future research to determine whether the complete multiplate method described by Nouws et al (1999) and + means that the b-lactam antimicrobial was detected in 90% of the time with 95% confidence. +/) means that the b-lactam antimicrobial was detected (Based on 30 samples at each concentration) in less than 90% of the time with 95% confidence.…”

“…Working solutions (0.1 ml) containing selected spiked antimicrobials were added to raw antimicrobial free milk (9.9 ml), and tested within 3 days. The analysis on each test plate included one blank sample and reference milk standards as described (Nouws et al, 1999;Rikilt-dlo, 1998). The spiked samples were randomized, coded in order to perform blind coded analysis and availed to the two laboratories.…”

Monitorización terapéutica de antibióticos: Nuevas metodologías: biosensores

“…El crecimiento bacteriano, evidenciado por el desarrollo de opacidad o cambio de color en el medio de cultivo es interpretado como ausencia del antibiótico, o presencia del mismo en una concentración inferior a la efectiva [13][14][15] . A pesar de lo rudimentario, estas pruebas son excepcionalmente sensibles y de bajo costo, por lo que hacen posible su masificación, aunque poseen una baja resolución cuantitativa y temporal, esta última limitada por un tiempo de incubación de varias horas.…”