Simultaneous quantification of Escherichia coli O157:H7 and Shigella boydii using a visual-antibody-macroarray

Abstract

Being high throughput, rapid, automated, economical, convenient to operate and highly sensitive, protein arrays have been widely used in the analysis of tumor markers and veterinary drug residues. Pathogenic microbes also can be detected qualitatively by DNA array or protein array; however, their high throughput detection and quantification remains a big obstacle. To evaluate the potentiality of protein arrays for multiple quantitative detection of microorganisms with naked eye examination without the help of any equipment, here we developed a visual-antibody-macroarray (VAMA) aiming at rapid and simultaneous quantification of Escherichia coli O157:H7 and Shigella boydii. The results show that this VAMA is highly specific and is able to distinguish mixed Escherichia coli O157:H7 and Shigella boydii synchronously. The detection limits are equivalent to 3.4 × 10(5) CFU mL(-1) and 3.2 × 10(5) CFU mL(-1), respectively, which conform to the results of plate counting and ELISA. Importantly, the examination can be solely performed with the naked eye. Therefore, we provide an easy, reliable and rapid method for quantitative analysis of microorganisms.

The application of nanoparticles in point-of-care testing (POCT) immunoassays

“…The combination of novel AuNPs with ICAs enhanced the color intensity by more than two orders of magnitude as compared to the visual-antibody-macroarray. 97 These reports verify that the morphology of AuNPs greatly influences the sensitivity of ICAs. ICA platforms have also been used to detect nucleic acids.…”

Development of a Bacterial Macroarray for the Rapid Screening of Targeted Antibody-Secreted Hybridomas

“…The specific surface area and porosity of the NC membrane will affect the adsorption to bacteria and possibly alter the detection performance, so the assessment of pore sizes of NC membranes is crucial. 31 In this work, FITC-labeled Escherichia coli O157:H7 ( E. coli O157:H7 ), Cronobacter sakazakii ( C. sakazakii ), Staphylococcus aureus ( S. aureus ), 32 and Listeria monocytogenes ( L. monocytogenes ) 33 were fixed on NC membranes of different pore sizes (0.22 µm, 0.45 µm, 0.8 µm, and 5.0 µm). Different surface structures of these NC membranes was observed under the scanning electron microscope (Philips XL30, Netherlands).…”

A rapid detection of Escherichia coli O157:H7 by competition visual antigen macroarray

“…After a chromogenic substrate such as DAB is added, the HRP catalyst can be fixed immediately by the NC membrane. (Wu et al, 2015)The development of a strongly binding, specific monoclonal antibody (Mab) is one of hurdles encountered in the use of protein arrays because a complicated serotype, low affinity of the antibody to the pathogen or other analyte being measured, and potential interference from contaminants are all problems that are often encountered when a strong antibody cannot be obtained. More importantly, a small chemical molecule antigen, such as a veterinary drug, can only produce a type of Mab that cannot be used for the “double antibody sandwich” method (Chen et al, 2009; Xu, Gan, Fang, Zheng, & Dong, 2007).…”