Bacterial Genetics & DNA Transfer I. Introduction to Bacterial Genetics Definition: Bacterial genetics studies how genetic material changes and transfers between cells, affecting traits like growth and antibiotic resistance. Genetic Material: In bacteria (e.g., E. coli), it consists of a single circular DNA molecule. Haploid Nature: Bacteria are haploid (one chromosome/one gene copy), meaning any mutation is immediately expressed. In contrast, human cells are diploid. Genome Size: Mycoplasma has the smallest genome among free-living bacteria. II. Mutations A mutation is a change in the DNA base sequence that may produce a new phenotype. Types of Mutations: Base Substitution: One base is replaced by another. Missense: Changes one amino acid. Nonsense: Creates a stop codon, producing a nonfunctional protein. Frameshift Mutation: Insertion or deletion of base pairs, shifting the ...
🔰pepsinogen I and II ⭕The levels of pepsinogen (PG) I and the PGI/II ratio are useful serologic markers for chronic atrophic gastritis. This study evaluated the performance and clinical implications of these markers in patients undergoing endoscopy. This study was carried at the gastrointestinal unit at AL-Yarmouk Teaching Hospital. Blood samples with antral biopsies were obtained from 127 patients who were complaining from gastroduodenal disease. Patients included 64 with chronic gastritis and 30 with gastric carcinoma. A further 33 healthy persons, uninfected with H.pylori were involved as a control group. Every gastric biopsy examined by histology and rapid urease test. In addition, patient's sera were screened for the presence of H.pyloriIgG antibodies, serum level of PGI and PGII. According to the histological data it was demonstrated that the adenocarcinoma patients were more prevalent than other type of gastric cancer. There was a significant p<0.05 increased level of p...
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