Combined Plate Microbial Assay (CPMA): A 6-plate-method for simultaneous first and second level screening of antibacterial residues in meat

Abstract

This paper proposes an improved high throughput microbial method for the simultaneous performance of first and second level screening for antibacterial residues in meat. It is based on growth inhibition of B. subtilis on agar medium pH 6, 7.2 and 8, of B. cereus on agar medium pH 5.9, of M. luteus on agar medium pH 8 and of E. coli on agar medium pH 7.2 (research or first level screening) and on the use of confirmatory solutions (Pase, Paba, MgSO4) for the identification or second level screening. In kidney control samples, dialysis membranes were interposed between samples and the agar surface to both prevent the action of lysozyme and reduce false positive results. The proposed method detects beta-lactams, sulfonamides, tetracyclines, aminoglycosides, macrolides and quinolones at MRL concentrations and reliably indicates the inhibitor family. Results are obtained in 18-24 h.

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

“…Although a multi-plate system is more laborious than a single plate system like the NDKT, in practice this disadvantage is outweighed by the fact that the current system enables group-identification, which significantly facilitates additional post-screening or chemical confirmation procedures. Compared to previously published tests (Calderon et al, 1996;Ferrini et al, 2006;Gaudin et al, 2004;Myllyniemi et al, 2001;Okerman et al, 2001) the presented system contains some notably differences. Effective detection of sulfonamides is achieved by the combination of the test organism B. pumilus CN607 and Diagnostic Sensitivity Test agar (DST) supplemented with trimethoprim (TMP).…”

“…For the detection of quinolones, a class of antimicrobials introduced relatively recently in veterinary medicine, usually an Escherichia coli test plate, as proposed by Ellerbroek (1991), is implemented (Ferrini et al, 2006;Gaudin et al, 2004;Myllyniemi et al, 2001;Okerman et al, 2001). E. coli however lacks sufficient sensitivity towards flumequine and oxolinic acid, so to be able to these two components at adequately low levels, we implemented an earlier published test plate based on Y. ruckeri (Pikkemaat et al, 2007).…”

“…However, with the announcement of official procedures for determining MRLs for food products of animal origin in 1990 (EC, 1990) following years, it appeared that the detection capacity of the EU-four plate method could not ensure MRL compliance in meat. As a response several improved plate methods were proposed (Calderon, Gonzalez, Diez, & Berenguer, 1996;Ferrini, Mannoni, & Aureli, 2006;Gaudin et al, 2004;Myllyniemi et al, 2001;Okerman et al, 2001). A major shortcoming of these methods however, is that they do not provide a suitable alternative for the labour intensive and difficult to standardize sample preparation procedure.…”

Comparison of three microbial screening methods for antibiotics using routine monitoring samples

“…Within the European Union, the EU 4 plate method [4] for several decades served as a reference method, but with the actual establishment of MRLs, the sensitivity of this method appeared insufficient for the MRLs in muscle. Several more sensitive methods have been developed since then [5][6][7][8][9], ranging from 5 to as many as 18 individual test plates.…”

Prevalence of antimicrobial residues in raw table eggs from farms and retail outlets in Enugu State, Nigeria

“…Antimicrobial residues in animal food products are of public health importance because of the adverse effects they have on humans. Some of these effects include hypersensitive reaction, development of resistant strains of microorganisms, carcinogenic effect and potential harmful effect on human intestinal micro flora (Ferrinie et al 2006;Jafari et al 2007;Reig and Todra 2008). The improper and indiscriminate use of veterinary drugs constitutes a major problem of contaminating animal food products with residues.…”