Rapid Affinity Immunochromatography Column-Based Tests for Sensitive Detection of Clostridium botulinum Neurotoxins and Escherichia coli O157

Abstract

Existing methods for detection of food-borne pathogens and their toxins are frequently time-consuming, require specialized equipment, and involve lengthy culture procedures and/or animal testing and are thus unsuitable for a rapid response to an emergency public health situation. A series of simple and rapid affinity immunochromatography column (AICC) assays were developed to detect Clostridium botulinum neurotoxin types A, B, E, and F and Escherichia coli O157 in food matrices. Specifically, for milk, grape juice with peach juice, and bottled water, the detection limit for the botulinum neurotoxin type A complex was 0.5 ng. Use of this method with a 10-ml sample would therefore result in a detection limit of 50 pg ml ؊l . Thus, this assay is approximately 2 orders of magnitude more sensitive than a comparable lateral-flow assay. For botulinum neurotoxin complex types B, E, and F, the minimum detection limit was 5 ng to 50 ng. Sensitive detection of E. coli O157 was achieved, and the detection limit was 500 cells. The AICC test was also shown to be specific, rapid, and user friendly. This test takes only 15 to 30 min to complete without any specialized equipment and thus is suitable for use in the field. It has the potential to replace existing methods for presumptive detection of botulinum neurotoxin types A, B, E, and F and E. coli O157 in contaminated matrices without a requirement for preenrichment.

Complexity of Botulinum Neurotoxins: Challenges for Detection Technology

“…Optimally, ELISAs based on mAb have to be tested against all the different subtypes of a given serotype. Indeed, a variation or lack in recognition of a certain subtype has been observed for some mAb and mAb-based ELISAs (Gibson et al 1987(Gibson et al , 1988Smith et al 2005;Kalb et al 2009Kalb et al , 2011bBrunt et al 2010).…”

“…This problem is usually less pronounced with pAb recognizing numerous epitopes on a target protein, but also pAb have been shown to neutralize BoNT subtypes differently (Kozaki et al 1977) or in extreme fail to recognize a certain subtype: Brunt and colleagues showed that a particular pAb directed against BoNT/F1 failed to recognize culture supernatants of a nonproteolytic F strain (Brunt et al 2010). Notably, the highest divergence among the subtypes is found in BoNT/F (36 %) (Raphael et al 2010a).…”

“…Using this rather straightforward technology, BoNT/C and D have been detected from culture supernatants within 40 min with sensitivities close to that of the MBA (Gessler et al 2005). Peck and colleagues recently expanded the method to detect BoNT/B, E, and F (Brunt et al 2010). BoNT/A has been detected from different clinical samples, food, or powder materials with a detection limit in the low pg/mL-range, similar to that of the MBA (Attrée et al 2007).…”

Current Methods for Detecting the Presence of Botulinum Neurotoxins in Food and Other Biological Samples

“…To this end, Brunt and colleagues (Brunt, Webb, and Peck, 2010) have developed a number of rapid affinity immunochromatography column (AICC) assays for the detection of BoNT serotypes A, B, E, and F in food matrices. These authors reported a detection limit for BoNT/A of 0.5 ng, two fold more sensitive than earlier reported lateral flow methods.…”

The Use of Phages and Aptamers as Alternatives to Antibodies in Medical and Food Diagnostics

“…Recently, alternative rapid methods, such as quantitative real-time PCR assays, have been developed for the detection of C. botulinum (Kirchner et al 2010;Satterfield et al 2010). Brunt et al (2010) developed a sensitive and rapid immunochromatography column-based test for the detection of BoNTs. Fig.…”