Evaluation of Immunomagnetic Separation for the Detection of Salmonella in Surface Waters by Polymerase Chain Reaction

Abstract

Salmonella spp. is associated with fecal pollution and capable of surviving for long periods in aquatic environments. Instead of the traditional, time-consuming biochemical detection, polymerase chain reaction (PCR) allows rapid identification of Salmonella directly concentrated from water samples. However, prevalence of Salmonella may be underestimated because of the vulnerability of PCR to various environmental chemicals like humic acid, compounded by the fact that various DNA polymerases have different susceptibility to humic acid. Because immunomagnetic separation (IMS) theoretically could isolate Salmonella from other microbes and facilitate removal of aquatic PCR inhibitors of different sizes, this study aims to compare the efficiency of conventional PCR combined with immunomagnetic separation (IMS) for Salmonella detection within a moderately polluted watershed. In our study, the positive rate was increased from 17.6% to 47% with nearly ten-fold improvement in the detection limit. These results suggest the sensitivity of Salmonella detection could be enhanced by IMS, particularly in low quality surface waters. Due to its effects on clearance of aquatic pollutants, IMS may be suitable for most DNA polymerases for Salmonella detection.

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

“…The presence of high background indigenous microflora and complex matrix in food also limits detection of pathogen from food samples. Again, pathogen often exist in viable but non-culturable states in food which cannot be detected by the conventional culture based method [ 5 ]. There is a great need for improved methods for foodborne pathogen detection in food matrices.…”

Composite Scores of Plasma Tau and β-Amyloids Correlate with Dementia in Down Syndrome

“…Although plasma biomarkers are less invasive and more cost-effective than CSF biomarkers, plasma biomarker data from Fortea et al’s study were nonconclusive. We recently developed a technology called immunomagnetic reduction (IMR), which is capable of assaying molecules at very low concentrations. − We have used this technology to evaluate plasma biomarkers in AD and DS patients and healthy controls, and demonstrated a decrease in Aβ40 and increase in Aβ42 levels in AD patients, a large increase Aβ40 and decrease in Aβ42 levels in DS patients with no dementia, and a decline in Aβ40 and tau and rise in Aβ42 levels in DS patients with dementia . In that study, we suggested that either Aβ40 or Aβ42/Aβ40 can be biomarkers for neurodegeneration in DS.…”

Benefits of Immunomagnetic Separation for Epitope Identification in Clinically Important Protein Antigens: A Case Study Using Ovalbumin, Carbonic Anhydrase I and Tau Protein

“…IMS employing superparamagnetic MPs coated with specific antibody has become an essential tool for high-throughput and low-cost enrichment/isolation of various biomolecules and cells from heterogeneous samples. Examples of IMS applications are: (i) extraction of bacterial cells from the food/biological samples followed by detection using real-time PCR [2][3][4][5][6][7] or mass spectrometry (MS) analysis [8][9][10], (ii) positive selection/removal of specific cells from blood, bone marrow and other biological samples [11][12][13][14][15][16][17][18][19][20], (iii) capturing and detection of clinically important protein biomarkers [21][22][23][24], etc. To increase the sensitivity IMS can also be performed in a microfluidic arrangement [25][26][27] or may be combined with detection using quantum dots (QDs) [28][29][30].…”