Biology subjects

Eltaher, S. M.

Publications and source records attributed to Eltaher, S. M..

2 recordsLinked to original sources

bioRxiv2019

Molecular Phylogenetic Analysis of 16S rRNA Sequences Identified Two lineages of H. pylori Strains Detected from Different Regions in Sudan Suggestive of Differential Evolution

BackgroundH. pylori is ubiquitous among humans, and one of the best studied examples of an intimate association between bacteria and humans. Under several diverse socio-demographic factors in Sudan, a continuous increase in the prevalence rate of H. pylori infection has been noticed which represents a major public health challenge. In this study, we analyzed the molecular evolution of H. pylori Strains detected from different ethnic and regions of Sudan using 16S rRNA gene and phylogenetic approach. Materials and methodsA total of 75 gastric biopsies taken from patients who had been referred for endoscopy from different regions of Sudan. The DNA extraction was done by using the guanidine chloride method. Two sets of primers (universal and specific for H. pylori) were used to amplify the 16S ribosomal gene. Sanger sequencing was performed; then Blast these sequences with those available in the NCBI nucleotide database. The evolutionary aspects were analyzed using a MEGA7 software. ResultMolecular detection of H. pylori has shown that 28 (37.33%) of patients were positive for H. pylori. Bivariate analysis has found no significant differences exhibited across sociodemographic, endoscopy series and H. pylori infection. Nucleotide variations were found at five nucleotide positions (positions 219, 305, 578, 741 and 763-764) and one insertion mutation (750_InsC_751) was present in sixty-seven percent (7/12) of our strains. The phylogenetic tree diverged into two lineages. ConclusionThe phylogenetic analysis of 16S rRNA sequences identified two lineages of H. pylori strains detected from different regions in Sudan. Sex mutations were detected in regions of the 16S rRNA not closely associated with either tetracycline or tRNA binding sites. 66.67% of them were located in the central domain of 16S rRNA. Studying the effect of these mutations on the functions of 16S rRNA molecules in protein synthesis and antibiotic resistance is of great importance.

microbiology↗

bioRxiv2019

Genetic analysis of TP53 gene mutations in exon 4 and exon 8 among esophageal cancer patients in Sudan

BackgroundEsophageal carcinoma (EC) represents the 1st rank among all gastrointestinal cancers in Sudan. Despite little publications, there is a deep absence of literature about the molecular pathogenesis of EC considering TP53 gene from Sudanese population.\n\nAimsIn this study, we performed the expression analysis on p53 protein level by immunohistochemical staining and examined its overexpression with p53 mutations in exons 4 and 8 among esophageal cancer patients in Sudan.\n\nMaterial and MethodsFixed tissue with 10% buffered formalin was stained by Hematoxlin and Eosin (H&E), Alcian blue-Periodic Acid Schiff (PAS) and Immunohistochemistry stain. PCR-RFLP was used to study the frequencies of p53 codon 72 R/P polymorphism. Conventional PCR and sanger sequencing were applied for exon 4 and exon 8. Then detection and functional analysis of SNPs and mutations were performed using various in bioinformatics tools.\n\nResultNuclear accumulations for p53 protein was detected in all of the esophageal carcinomas examined while no accumulations were observed in normal control sections. Four patients with immune-positive for p53 showed no mutations in p53 gene (exon4 and exon8). The incidence of the homozygous mutant variant Pro/Pro was higher in esophageal cancerous patients comparing to healthy control subject 20(71. 4%) vs. 1(10%), respectively (p=0.0026). In exon 4, no mutation was detected other than NG_017013.2:g. 16397C>G. While in exon 8, g.18783-18784AG>TT, g.18803A>C, g.18860A>C, g.18845A>T and g.18863_ 18864 InsT were observed.\n\nConclusionwe found a significant association between the overexpression of TP53 protein and mutation in exon 4 and 8. A silent mutation P301P was detected in all of examined cases. Two patients who diagnosed with small cell sarcoma have shared the same mutations in exon8. Further studies with large sample size are required to demonstrate the usefulness of these mutations in the screening of EC especially SCCE.

cancer biology↗