Macroporous hydrophobic cloth (polymacron) as a solid phase for nucleic acid probe hybridizations

Cloth-based hybridization array system for the identification of antibiotic resistance genes in Salmonella

A simple macroarray system based on the use of polyester cloth as the solid phase for DNA hybridization has been developed for the identification and characterization of bacteria on the basis of the presence of various virulence and toxin genes. In this approach, a multiplex polymerase chain reaction (PCR) incorporating digoxigenin-dUTP is used to simultaneously amplify different marker genes, with subsequent rapid detection of the amplicons by hybridization with an array of probes immobilized on polyester cloth and immunoenzymatic assay of the bound label. As an example of the applicability of this cloth-based hybridization array system (CHAS) in the characterization of foodborne pathogens, a method has been developed enabling the detection of antibiotic resistance and other marker genes associated with the multidrug-resistant food pathogen Salmonella enterica subsp. enterica serotype Typhimurium DT104. The CHAS is a simple, cost-effective tool for the simultaneous detection of amplicons generated in a multiplex PCR, and the concept is broadly applicable to the identification of key pathogen-specific marker genes in bacterial isolates.

Cloth-based hybridization array system for the detection of Clostridium botulinum type A, B, E, and F neurotoxin genes

A simple cloth-based hybridization array system was developed for the characterization of Clostridium botulinum isolates based on the botulinum neurotoxin serotype. Bacterial isolates were subjected to a multiplex PCR incorporating digoxigenin-dUTP and primers targeting the four botulinum neurotoxin gene serotypes (A, B, E, and F) predominantly involved in human illness, followed by hybridization of the amplicons with an array of toxin gene-specific oligonucleotide probes immobilized on polyester cloth and subsequent immunoenzymatic assay of the bound digoxigenin label. This system provided sensitive and specific detection of the different botulinum neurotoxin gene markers in a variety of C. botulinum strains, exhibiting the expected patterns of reactivity with a panel of target and nontarget organisms.

Cloth-based hybridization array system for the detection of multiple antibiotic resistance genes in Salmonella enterica subsp. enterica serotype Typhimurium DT104

AIMS

A simple DNA macroarray system was developed for detection of antibiotic resistance and other marker genes associated with the multidrug-resistant food pathogen Salmonella enterica subsp. enterica serotype Typhimurium DT104.

METHODS AND RESULTS

A multiplex polymerase chain reaction (PCR) incorporating digoxigenin-dUTP was used to simultaneously amplify seven marker sequences, with subsequent rapid detection of the amplicons by hybridization with an array of probes immobilized on polyester cloth and immunoenzymatic assay of the bound label. This system provided sensitive detection of the different genetic markers in the S. Typhimurium DT104 genome, giving positive reactions with as few as 10 CFU, and the hybridizations were highly specific, with no reactions of amplicons with heterologous probes on the array.

CONCLUSIONS

This cloth-based hybridization array system (CHAS) provides a simple, cost-effective tool for monitoring S. Typhimurium DT104 in foods and their production environment.

SIGNIFICANCE AND IMPACT OF THE STUDY

The CHAS is a simple and cost-effective tool for the simultaneous detection of amplicons generated in a multiplex PCR, and the concept is broadly applicable to the detection and characterization of food pathogens.