Immunomagnetic separation and rapid detection of bacteria using bioluminescence and microfluidics

Qiu, Jingmin; Zhang, Yun; Chen, Hui; Lin, Jin‐Ming

doi:10.1016/j.talanta.2009.05.003

Cited by 77 publications

(58 citation statements)

References 25 publications

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“…The near-wall behavior of swimmers has received a lot of attention (see, e.g., Refs. and the references therein) and turns out to have a profound role in many biological processes, such as biofilm formation [80,81] and sperm motility [67,[82][83][84], as well as microfluidic setups used for manipulation and separation of active agents, such as bacteria [5,85,86].…”

Section: Introductionmentioning

confidence: 99%

Population splitting of rodlike swimmers in Couette flow

et al. 2017

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We present a quantitative analysis on the response of a dilute active suspension of self-propelled rods (swimmers) in a planar channel subjected to an imposed shear flow. To best capture the salient features of shear-induced effects, we consider the case of an imposed Couette flow, providing a constant shear rate across the channel. We argue that the steady-state behavior of swimmers can be understood in the light of a population splitting phenomenon, occurring as the shear rate exceeds a certain threshold, initiating the reversal of swimming direction for a finite fraction of swimmers from down-to upstream or vice versa, depending on swimmer position within the channel. Swimmers thus split into two distinct, statistically significant and oppositely swimming majority and minority populations. The onset of population splitting translates into a transition from a self-propulsiondominated regime to a shear-dominated regime, corresponding to a unimodal-to-bimodal change in the probability distribution function of the swimmer orientation. We present a phase diagram in terms of the swim and flow Péclet numbers showing the separation of these two regimes by a discontinuous transition line. Our results shed further light on the behavior of swimmers in a shear flow and provide an explanation for the previously reported non-monotonic behavior of the mean, near-wall, parallel-to-flow orientation of swimmers with increasing shear strength.

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Section: Introductionmentioning

confidence: 99%

Population splitting of rodlike swimmers in Couette flow

et al. 2017

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“…The lowest initial contamination rate tested, i.e., 1 to 10 CFU per 25 g or ml, could be detected in chicken, infant formula, milk, and chocolate milk, meeting the required detection limit for Salmonella according to the methods of the USDA Microbiology Laboratory Guidebook (53) and the FDA Bacteriological Analytical Manual (54) and significantly reducing detection times, from 72 h to 24 h. HRP-conjugated LTF offers a rapid enzyme-linked sandwich detection assay. Colorimetric or fluorescent ELISA-based assays have been successfully combined with IMS for rapid identification and quantification of bacterial contaminations (12,14,15). We therefore assessed the functionality of the phage S16 LTF as a secondary probe to detect bead-bound Salmonella (Fig.…”

mentioning

confidence: 99%

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

Denyes

Dunne

Steiner

et al. 2017

Appl Environ Microbiol

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Bacteriophage-based assays and biosensors rival traditional antibodybased immunoassays for detection of low-level Salmonella contaminations. In this study, we harnessed the binding specificity of the long tail fiber (LTF) from bacteriophage S16 as an affinity molecule for the immobilization, enrichment, and detection of Salmonella. We demonstrate that paramagnetic beads (MBs) coated with recombinant gp37-gp38 LTF complexes (LTF-MBs) are highly effective tools for rapid affinity magnetic separation and enrichment of Salmonella. Within 45 min, the LTF-MBs consistently captured over 95% of Salmonella enterica serovar Typhimurium cells from suspensions containing from 10 to 10 5 CFU · ml Ϫ1 , and they yielded equivalent recovery rates (93% Ϯ 5%, n ϭ 10) for other Salmonella strains tested. LTF-MBs also captured Salmonella cells from various food sample preenrichments, allowing the detection of initial contaminations of 1 to 10 CFU per 25 g or ml. While plating of bead-captured cells allowed ultrasensitive but time-consuming detection, the integration of LTF-based enrichment into a sandwich assay with horseradish peroxidaseconjugated LTF (HRP-LTF) as a detection probe produced a rapid and easy-to-use Salmonella detection assay. The novel enzyme-linked LTF assay (ELLTA) uses HRP-LTF to label bead-captured Salmonella cells for subsequent identification by HRP-catalyzed conversion of chromogenic 3,3=,5,5=-tetramethylbenzidine substrate. The color development was proportional for Salmonella concentrations between 10 2 and 10 7 CFU · ml Ϫ1 as determined by spectrophotometric quantification. The ELLTA assay took 2 h to complete and detected as few as 10 2 CFU · ml Ϫ1 S. Typhimurium cells. It positively identified 21 different Salmonella strains, with no cross-reactivity for other bacteria. In conclusion, the phage-based ELLTA represents a rapid, sensitive, and specific diagnostic assay that appears to be superior to other currently available tests. IMPORTANCEThe incidence of foodborne diseases has increased over the years, resulting in major global public health issues. Conventional methods for pathogen detection can be laborious and expensive, and they require lengthy preenrichment steps. Rapid enrichment-based diagnostic assays, such as immunomagnetic separation, can reduce detection times while also remaining sensitive and specific. A critical component in these tests is implementing affinity molecules that retain the ability to specifically capture target pathogens over a wide range of in situ applications. The protein complex that forms the distal tip of the bacteriophage S16 long tail fiber is shown here to represent a highly sensitive affinity molecule for the specific enrichment and detection of Salmonella. Phage-encoded long tail fibers have huge potential for development as novel affinity molecules for robust and specific diagnostics of a vast spectrum of bacteria.

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“…The most popular variant of the selective isolation of bacteria is immunomagnetic separation, which exploits bacteriaspecific antibodies immobilized on magnetic particles [9][10][11][12][13][14]. After the incubation with the sample, the particles with the captured bacteria can be collected with a magnet, washed, and resuspended in a desired volume of liquid for further analysis.…”

Section: Introductionmentioning

confidence: 99%

Application of immobilized synthetic anti-lipopolysaccharide peptides for the isolation and detection of bacteria

Sandetskaya

Engelmann

Brandenburg

et al. 2015

Eur J Clin Microbiol Infect Dis

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The molecular detection of microorganisms in liquid samples generally requires their enrichment or isolation. The aim of our study was to evaluate the capture and pre-concentration of bacteria by immobilized particular cationic antimicrobial peptides, called synthetic anti-lipopolysaccharide peptides (SALP). For the proof-of-concept and screening of different SALP, the peptides were covalently immobilized on glass slides, and the binding of bacteria was confirmed by microscopic examination of the slides or their scanning, in case of fluorescent bacterial cells. The most efficient SALP was further tethered to magnetic beads. SALP beads were used for the magnetic capture of Escherichia coli in liquid samples. The efficiency of this strategy was evaluated using polymerase chain reaction (PCR). Covalently immobilized SALP were capable of capturing bacteria in liquid samples. However, PCR was hampered by the unspecific binding of DNA to the positively charged peptide. We developed a method for DNA recovery by the enzymatic digestion of the peptide, which allowed for a successful PCR, though the method had its own adverse impact on the detection and, thus, did not allow for the reliable quantitative analysis of the pathogen enrichment. Immobilized SALP can be used as capture molecules for bacteria in liquid samples and can be recommended for the design of the assays or decontamination of the fluids. For the accurate subsequent detection of bacteria, DNA-independent methods should be used.

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Immunomagnetic separation and rapid detection of bacteria using bioluminescence and microfluidics

Cited by 77 publications

References 25 publications

Population splitting of rodlike swimmers in Couette flow

Population splitting of rodlike swimmers in Couette flow

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

Application of immobilized synthetic anti-lipopolysaccharide peptides for the isolation and detection of bacteria

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