Rapid detection of trace Salmonella in milk and chicken by immunomagnetic separation in combination with a chemiluminescence microparticle immunoassay.
Anal Bioanal Chem
; 411(23): 6067-6080, 2019 Sep.
Article
em En
| MEDLINE
| ID: mdl-31273413
ABSTRACT
Rapid detection of trace Salmonella is urgently needed to ensure food safety. We present an innovative pretreatment strategy, based on a two-step enrichment culture and immunomagnetic separation, combined with a chemiluminescence microparticle immunoassay to detect at least one proliferative Salmonella cell in 25 mL (25 g) food. The capture performance of immunomagnetic beads (IMBs) of sizes for Salmonella was investigated, and the IMBs of size 2.8 µm showed a high capture efficiency of 60.7% in 25 mL milk and 74.5% in 25 mL chicken culture filtrate, which ensured the successful capture of trace Salmonella after 2.5 h in situ enrichment even from only one Salmonella cell. The separated Salmonella cells, reaching an amount of 103 colony-forming units (CFU) by a secondary enrichment for 3 h, were detected by a horseradish peroxidase chemiluminescence reaction with 4-(1-imidazolyl)phenol as an enhancer, which evidenced a linear response for Salmonella concentrations ranging from 2.3 × 102 to 7.8 × 104 CFU/mL. The entire detection process was completed within 8 h, with a very low detection limit of 1 CFU/25 mL (25 g), which was verified by colony counting, and a small degree of interference of 0.17-1.06%. Trace Salmonella from five different serovars in milk and chicken was successfully detected without false negative or false positive results. Furthermore, this study provides a basis to develop a fully automated instrument based on IMBs that includes all steps from sample preparation to chemiluminescence microparticle immunoassay for high-throughput screening of foodborne pathogens. Graphical abstract.
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Base de dados:
MEDLINE
Assunto principal:
Aves Domésticas
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Salmonella
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Contaminação de Alimentos
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Leite
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Medições Luminescentes
Tipo de estudo:
Diagnostic_studies
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Evaluation_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article