(Association of Genetic Variation and Gene Expression of the PVC Operon with Biofilm Formation in Clinical Isolates of Pseudomonas aeruginosa)

Master’s Discussion

The College of Science for Women / University of Baghdad examined the thesis entitled (Association of Genetic Variation and Gene Expression of the PVC Operon with Biofilm Formation in Clinical Isolates of Pseudomonas aeruginosa) of the student (Zena Loay Abdul Jabbar), in Partial Fulfilment of the Requirements for the Degree of Master in Biology / Genetics.

Objectives of the Thesis

The study aims to determine the relationship between gene expression patterns of the pvcABCD gene cluster in clinical isolates of Pseudomonas aeruginosa from different infection sources, and the genetic variations associated with biofilm formation and antibiotic resistance.

Content of the Thesis

This study includes the analysis of gene expression and genetic variation of the pvcABCD operon in Pseudomonas aeruginosa isolated from patients with burns, wounds, diabetic foot ulcers, in addition to urine samples. The study was conducted in Baghdad, where 137 clinical specimens were collected from different sources. The isolates were identified using bacteriological methods and confirmed by molecular techniques. Furthermore, genetic variation in the pvcA and pvcC genes was investigated in a number of isolates and compared with reference strains.

recommendations

The most important recommendations which the study has come up with and the average obtained:

The study concluded that there is a clear variation in the gene expression levels of the pvcABCD operon in Pseudomonas aeruginosa, where a general decrease in the gene expression of the pvcA gene was recorded, while the pvcB, pvcC, and pvcD genes showed a noticeable increase in gene expression. The results also showed a relationship between the high gene expression of this operon’s genes and the increased ability of the isolates to form biofilms, especially in strong and moderate types. The results also showed differences in gene expression according to the source of the isolate, where urine isolates recorded the highest expression of the pvcA gene, while burn and diabetic foot ulcer isolates showed an increase in the gene expression of the remaining operon genes compared to wound isolates, which showed a general decrease. The study of genetic variation also revealed the presence of missense and silent mutations in the pvcA gene, which were associated with an increase in gene expression levels, indicating the role of compensatory regulatory mechanisms, while pvcC showed high genetic stability. These results indicate an important role of the pvcABCD operon in enhancing bacterial adaptation and virulence.