Highly efficient and specific separation of Staphylococcus aureus from lettuce and milk using Dynabeads protein G conjugates

Abstract

An immunomagnetic separation method using antibody-coated Dynabeads Protein G was developed for specific and efficient separation of in lettuce and whole milk. The amount of immunomagnetic beads (IMBs) and conjugation conditions were optimized. A high capture efficiency was obtained with 0.4 mg of IMBs, an immunoreaction time of 20 min, and a separation time of 1 min without wash. Under optimal conditions, the capture efficiency (CE) for 10-10 CFU/mL of was higher than 91.46%. The IMBs showed high specificity even with a high constant number (10 CFU/mL) of ,, and . The CE of IMBs against at concentrations from 10 to 10 CFU/mL ranged from 78.70 to 94.77% for lettuce and 60.0 to 73.27% for milk samples. This IMS can be an appropriate selection for combining with bacterial detection method or efficient isolation procedure for from foods.

Rapid and visual detection of Staphylococcus aureus in milk using a recombinase polymerase amplification-lateral flow assay combined with immunomagnetic separation

“…Therefore, the diameter of IMBs, the amount of IMBs and immunoreaction time, which could affect the capture efficiency for S. aureus , was optimized in this study. Our findings are similar to other reports of larger beads being more effective in capturing bacteria than smaller beads of the same density (Li et al, 2019; Tu et al, 2009; Wei et al, 2016). The reason may be that in contrast to small beads, larger beads can travel through a larger volume of sample solution and have greater opportunity to interact with the target bacteria and thus result in higher CE values (Tu et al, 2009).…”

Photodynamic inactivation of planktonic Staphylococcus aureus by sodium magnesium chlorophyllin and its effect on the storage quality of lettuce

“…More importantly, SMC-mediated PDI effectively inactivated S. aureus on lettuce. Lettuce is one of the most common vegetables worldwide that can be eaten raw, and it is very susceptible to S. aureus infection during processing and storage [5], which poses a threat to human health. In the present study, the sterilization time was set to 30 min, as per the method of Yilin Lin [41], which greatly maintained the freshness of the lettuce after picking.…”

“…In addition, the bacteria is widespread in the food industry and has become the main source of contamination by foodborne pathogens [2]. As a very popular vegetable, lettuce is eaten raw without heating or cooking, which is at risk of being contaminated by S. aureus [5]. Therefore, the sterilization and control of S. aureus are closely related to food safety and human health.…”

An Innovative Protocol for Metaproteomic Analyses of Microbial Pathogens in Cystic Fibrosis Sputum

“…Each procedure was investigated for the enrichment success microscopically (Figure S2). Since S. aureus is one of the most prevalent and important CF pathogens, we additionally tested an enrichment protocol combining S. aureus specific antibodies and magnetic beads adapted from (Bicart-See et al, 2016;Wei et al, 2016) (Figure S2). However, neither density gradient centrifugation, nor antibody/ magnetic bead enrichment resulted in a reproducible and sufficient enrichment.…”