Detection of salmonella sp in chicken cuts using immunomagnetic separation

Abstract

The immunomagnetic separation (IMS) is a technique that has been used to increase sensitivity and specificity and to decrease the time required for detection of Salmonella in foods through different methodologies. In this work we report on the development of a method for detection of Salmonella in chicken cuts using in house antibody-sensitized microspheres associated to conventional plating in selective agar (IMS-plating). First, protein A-coated microspheres were sensitized with polyclonal antibodies against lipopolysacharide and flagella from salmonellae and used to standardize a procedure for capturing Salmonella Enteritidis from pure cultures and detection in selective agar. Subsequently, samples of chicken meat experimentally contaminated with S. Enteritidis were analyzed immediately after contamination and after 24h of refrigeration using three enrichment protocols. The detection limit of the IMS-plating procedure after standardization with pure culture was about 2x10 CFU/mL. The protocol using non-selective enrichment for 6-8h, selective enrichment for 16-18h and a post-enrichment for 4h gave the best results of S. Enteritidis detection by IMS-plating in experimentally contaminated meat. IMSplating using this protocol was compared to the standard culture method for salmonellae detection in naturally contaminated chicken cuts and yielded 100% sensitivity and 94% specificity. The method developed using in house prepared magnetic microespheres for IMS and plating in selective agar was able to diminish by at least one day the time required for detection of Salmonella in chicken products by the conventional culture method.

Evaluation of microplate immunocapture method for detection of Vibrio cholerae, Salmonella Typhi and Shigella flexneri from food

“…Wang et al [6] reported an IMS-PCR method for detection of Alicyclobacillus acidoterrestris in apple juice has better sensitivity, specificity, and accuracy (90.9%, 97.0% and 96.2%, respectively). Conceicao et al [28] reported an IMS-Plating method with antibody coated polystyrene microspheres for detection of Salmonella sp. in chicken cut with high sensitivity (100%) and specificity (94%).…”

Modified Bacteriophage S16 Long Tail Fiber Proteins for Rapid and Specific Immobilization and Detection of Salmonella Cells

“…2B). While cross-reactivity of Enterobacteriaceae is a common problem for antibody-based IMS of Salmonella strains (22,50), this was not observed for the LTF-MBs. LTF-MBs can enrich Salmonella from contaminated food preenrichments.…”

Detection of quinolone-resistance mutations in Salmonella spp. strains of epidemic and poultry origin

“…The main source of Salmonella infection for humans is chicken meat, pork, eggs and egg products (5, 16). The non-therapeutic use of fluroquinolones in veterinary medicine, as in prophylactic supplements or growth-promoting agents, can facilitate the selection of resistant bacteria or reduce susceptibility to these antimicrobials.…”