Development of Bacteriostatic DNA Aptamers for Salmonella

Abstract

Salmonella is one of the most dangerous and common food-borne pathogens. The overuse of antibiotics for disease prevention has led to the development of multidrug resistant Salmonella. Now, more than ever, there is a need for new antimicrobial drugs to combat these resistant bacteria. Aptamers have grown in popularity since their discovery, and their properties make them attractive candidates for therapeutic use. In this work, we describe the selection of highly specific DNA aptamers to S. enteritidis and S. typhimurium. To evolve species-specific aptamers, twelve rounds of selection to live S. enteritidis and S. typhimurium were performed, alternating with a negative selection against a mixture of related pathogens. Studies have shown that synthetic pools combined from individual aptamers have the capacity to inhibit growth of S. enteritidis and S. typhimurium in bacterial cultures; this was the result of a decrease in their membrane potential.

Selection of DNA aptamers against Human Cardiac Troponin I for colorimetric sensor based dot blot application

“…They used SPR (Surface Plasmon Resonance) assay to detect binding between Troponin I protein and aptamer and perhaps because, we used a full length aptamer which was flanked by both primer sequences, whereas Mamoru Hyodo and coworkers found that only some of nucleotides were responsible for binding (Ara et al, 2012), also in a study by Zamay, all truncated aptamers showed better binding abilities to target, indicating that primer sites do not participate in binding recognition. This is likely the result of decreased negative charge and steric hindrance of the aptamer caused by the removal of the primer binding portion (Kolovskaya et al, 2013). Lin-Yue believes that the stem loop modification of aptamer can be useful in identifying target domains, getting rid of excessive unnecessary nucleotides (Kaur and Yung, 2012).…”

Aptamers against pathogenic microorganisms

“…LOD is 25 CFU/ml in bacterial suspension.Duan et al (2013a)   S. typhimurium whole   live cellsDNAImpedimetric aptasensor. LOD is 600 CFU/ml in bacterial suspension.Labib et al (2012b) and Kolovskaya et al (2013)   S. enteritidis whole   live cellsDNAImpedimetric biosensor. LOD is 600 CFU/ml in bacterial suspension.Labib et al (2012a)  Lateral flow aptasensor.…”

“…Whole bacterium cells were also used by Berezovski and co-workers for the selection of DNA aptamers against S. enterica serotype Typhimurium and S. enterica serotype Enteritidis (Kolovskaya et al, 2013; Labib et al, 2012b). A mixture of aptamers selected against S. typhimurium inhibited the growth of the bacteria on Petri dishes, and the STYP-3 aptamer with the highest binding affinity ( K d  = 25 nM) was applied for the development of an impedimetric biosensor.…”

Aptamers in the Diagnosis of Rickettsiosis Sensu Lato

“…DNA aptamers, capable of binding and inhibiting bacterial tubercle infection, have also been described (Xiaolian & Fan 2008), as well as aptamers against cytolysin toxin of enterococci (Morrissey & Haeberli 2003), Bacillus cereus and Salmonella (Kolovskaya et al 2013). However, the prohibitive cost of aptamers in comparison to traditional antibiotics limits their applicability in this field, except where antibiotic resistance or lack of adequate antibiotics make them the preferred choice.…”