Kinetics of catalyzed hydrolysis of 4-methylumbelliferyl caprylate (MUCAP) salmonella reagent

Clinical identification of the pathogenic bacterium Moraxella catarrhalis in cultures relies on the detection of bacterial butyrate esterase (C4-esterase) using a coumarin-based fluorogenic substrate, 4-methylumbelliferyl butyrate. However, this classical probe may give falsepositive responses because of its poor stability and lack of specificity. Here, we report a new colorimetric and fluorogenic probe design employing a meso-ester-substituted boron dipyrromethene (BODIPY) dye for the specific detection of C4-esterase activity expressed by M. catarrhalis. This new probe has resistance to nonspecific hydrolysis that is far superior to the classical probe and also selectively responds to esterase with rapid colorimetric and fluorescence signal changes and large "turn-on" ratios. The probe was successfully applied to the specific detection of M. catarrhalis with high sensitivity.

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“…freundii does not possess esterase activity, although Salmonella spp. possess a C8-esterase activity. − …”

Section: Resultsmentioning

confidence: 99%

Selective Butyrate Esterase Probe for the Rapid Colorimetric and Fluorogenic Identification of Moraxella catarrhalis

et al. 2020

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“…20 double-blind samples with Salmonella and without Salmonella solution were prepared in sterile Eppendorf ® tubes at room temperature. The 4-MUCAP fluorogenic substrate presents blue fluorescence when exposed to Salmonella , but not S. aureus , or E. coli [ 24 ]. Two-tail analysis with Fisher’s test was employed to evaluate the prediction given, indicating that the method can successfully predict the outcome.…”

Section: Methodsmentioning

confidence: 99%

Design and Development of Magnetic Iron Core Gold Nanoparticle-Based Fluorescent Multiplex Assay to Detect Salmonella

et al. 2022

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Salmonella is a bacterial pathogen which is one of the leading causes of severe illnesses in humans. The current study involved the design and development of two methods, respectively using iron oxide nanoparticle (IONP) and iron core gold nanoparticle (ICGNP), conjugated with the Salmonella antibody and the fluorophore, 4-Methylumbelliferyl Caprylate (4-MUCAP), used as an indicator, for its selective and sensitive detection in contaminated food products. Twenty double-blind beverage samples, spiked with Salmonella enteritidis, Staphylococcus aureus, and Escherichia coli, were prepared in sterile Eppendorf® tubes at room temperature. The gold layer and spikes of ICGNPs increased the surface areas. The ratio of the surface area is 0.76 (IONPs/ICGNPs). The comparative sensitivity and specificity of the IONP-based and the ICGNP-based methods to detect Salmonella were determined. The ICGNP method shows the limit of detection is 32 Salmonella per mL. The ICGNPs had an 83.3% sensitivity and a 92.9% specificity value for the presence and detection of Salmonella. The IONP method resulted in a limit of detection of 150 Salmonella per mL, and a 66.7% sensitivity and 83.3% specificity for the presence and detection of Salmonella. The higher surface area of ICGNPs increases the efficiency of detection. The monitoring of Salmonella can thus be achieved by a rapid magnetic fluorescent assay using a smartphone for image capture and analyze, providing quantitative results. The findings from the present study would help to detect Salmonella rapidly in water. It can improve the microbial quality of water and food safety due to the presence of Salmonella in the water environment.

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“…Typhimurium. There is one fluorescent substrate, 4-methylumbelliferyl caprylate (MUCAP), for S. Typhimurium [46]. However, MUCAP is non-soluble in water, and thus is not compatible for aqueous in-droplet applications.…”

Section: Plos Onementioning

confidence: 99%

Microfluidic droplet application for bacterial surveillance in fresh-cut produce wash waters

et al. 2020

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Foodborne contamination and associated illness in the United States is responsible for an estimated 48 million cases per year. Increased food demand, global commerce of perishable foods, and the growing threat of antibiotic resistance are driving factors elevating concern for food safety. Foodborne illness is often associated with fresh-cut, ready-to-eat produce commodities due to the perishable nature of the product and relatively minimal processing from farm to the consumer. The research presented here optimizes and evaluates the utility of microfluidic droplets, also termed ultra-miniaturized bioreactors, for rapid detection of viable Salmonella enterica ser. Typhimurium in a shredded lettuce wash water acquired from a major Mid-Atlantic produce processing facility (denoted as Producer) in the U.S. Using a fluorescently-labeled anti-S. Typhimurium antibody and relative fluorescence intensities, paired with in-droplet incubation, S. Typhimurium was detected and identified with 100% specificity in less than 5 h. In initial optimization experiments using S. Typhimurium-spiked sterile water, the relative fluorescence intensity of S. Typhimurium was approximately two times that of the observed relative intensities of five non-S. Typhimurium negative controls at 4-h incubation in droplets containing Rappaport-Vasiliadis (RV) broth at 37˚C: relative fluorescence intensity for S.

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Kinetics of catalyzed hydrolysis of 4-methylumbelliferyl caprylate (MUCAP) salmonella reagent

Cited by 8 publications

References 37 publications

Selective Butyrate Esterase Probe for the Rapid Colorimetric and Fluorogenic Identification of Moraxella catarrhalis

Selective Butyrate Esterase Probe for the Rapid Colorimetric and Fluorogenic Identification of Moraxella catarrhalis

Design and Development of Magnetic Iron Core Gold Nanoparticle-Based Fluorescent Multiplex Assay to Detect Salmonella

Microfluidic droplet application for bacterial surveillance in fresh-cut produce wash waters

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