A lateral flow assay for identification of Escherichia coli by ribosomal RNA hybridisation

Abstract

Existing technologies for analysis of microbiological contaminants in food or clinical samples are often expensive and require laboratory settings and trained personnel. Here we present a lateral flow assay employing gold nanoparticle-oligodeoxynucleotide conjugates and four-component sandwich hybridisation for direct detection of specific sequences in bacterial 16S ribosomal RNA. Combined with rapid "one step" lysis the developed procedure allows detection of 5 × 10(4) colony forming units per mL Escherichia coli within less than 25 minutes. Several Escherichia coli strains were detected successfully, whereas non-related as well as closely related bacterial species produced no signal. The developed nucleic acid lateral flow assay is inexpensive, rapid to perform and requires no nucleic acid amplification step.

Development of a Gold Nanoparticle-Based Lateral-Flow Immunoassay for Pneumocystis Pneumonia Serological Diagnosis at Point-of-Care

“…Lateral flow immunoassays (LFIA) offer an easy solution to these limitations as they are a simple, rapid and user friendly technique, that do not require time-consuming instrumental methods or technical expertise, allowing a low-cost point-of-care alternative (Chan et al, 2013;Pöhlmann et al, 2014;Li et al, 2015;Singh et al, 2015). Although LFIA is a well-recognized technique, a specific serological biomarker for PcP diagnosis has not been established (Morris and Masur, 2011;Esteves et al, 2015;Matos and Esteves, 2016).…”

Development of a dry-reagent-based nucleic acid-sensing platform by coupling thermostabilised LATE-PCR assay to an oligonucleotide-modified lateral flow biosensor

“…The detection limit reported in this study which is 1 pg of genomic DNA is lower than that of a LAMP-NALFIA reported by Nimitphak et al (2008) (1 ng), a PCR-NALFIA by Blazkova et al (2009) (50 pg) and a LAMP-NALFIA by Kaewphinit et al (2013) (5 pg) whereas a PCR-NALFIA developed by Soo et al (2006) reported a similar LOD of 10 CFU/ml. An amplification-free NALFIA assay described by Pohlmann et al (2014) reported a higher detection limit of 10 4 CFU/ml.…”

A sample-to-answer, portable platform for rapid detection of pathogens with a smartphone interface

“…Alternatively, lateral-flow strip assays (LFSA), which are also based on antigen-antibody interactions, have been proven to be rapid (15-30 min) and relatively cheap; unfortunately, their lack of sensitivity and proneness to generating false-negative results in individuals infected with low concentrations of bacteria or viruses have limited their widespread adoption in the diagnostic clinic. [10][11][12] Alternatively, polymerase chain reaction (PCR) is also widely used for pathogen detection nowadays since nucleic acid sequences specific to a wide variety of microbes can be exponentially amplified to detectable levels in only two hours or less. Furthermore, the PCR assays are generally highly sensitive as well.…”