Application of Metagenomic Study for the Detection of Diphtheria Toxin Gene of Corynebacterium diphtheriae in Patients Displaying Symptoms of Pharyngitis in Kaduna State

Abstract

This study was set to detect the A and B subunit of Diphtheria toxin gene among patients with pharyngitis and to identify which of the possible biovars is endemic in Kaduna State. The result of standard collection of twenty-two (22) throat swab samples of patients using standard technique of purposive sampling, packing in sterile water at 4°C and DNA extraction using the phenol/ chloroform extraction method gave two 2 (9%) positive PCR samples out of the twenty-two, (22) throat swabs analysed; both A and B subunits of the gene’s amplicon were identified at 248bp and 297bp respectively. Sanger’s (dye-terminator) sequencing of one of the genes’ two, 2 subunits yielding two sequences obtained in the fasta format for bioinformatics analysis using the blast tool at the NCBI website. The 2 subunits of the gene were homologous to the biovars gravis and mitis complete coding sequence gene of Corynebacterium diphtheriae biovar mitis and gravis strains with percentage identity of 97 to both strains. Mutation in the 2 subunits of genes was also noticed with a total of 8 gaps that signify indels.