Molecular screening of Antibiotic Resistance Genes in Blue-Green Algae and pathogenic Bacteria Isolated from Local Environmental and clinical sources

Abstract

Background: Blue-green algae can adapt to different environmental conditions through physiological and biochemical responses. Their tolerance to antibiotics may also be associated with specific resistance mechanisms, including antibiotic-inactivating enzymes encoded by resistance genes. This is due to their possession of resistance genes, including the bla gene, which encode the β-lactamase enzyme responsible for breaking down penicillin. Objective: The study aimed to detect the presence of antibiotic resistance genes in local isolates of blue-green algae and compare them with pathogenic bacterial isolates. Methodology: Eight isolates of blue-green algae were obtained from the Euphrates River and purified on BG11 medium, while four pathogenic bacterial isolates were obtained from Ramadi Teaching Hospital and identified using microscopic examination and standard biochemical tests. Deoxyribonucleic acid (DNA) was extracted from all samples, and PCR was used to detect six resistance genes: bla, cat, erm, npt, aadA, gmr. Results: The results showed a great similarity in the patterns of resistance genes between algae and bacteria, particularly the bla gene, which appeared in most species of blue-green algae and pathogenic bacteria. The erm and cat genes were also detected in a large number of the isolates examined.Among the samples studied, Chrococcus sp. and Escherichia coli were the two species with the most resistance genes. The genus Oscillatoria sp.however, was less resistant, as the results showed that it possessed only two genes: gmr and aadA. Other resistance genes, such as bla and cat, were not detected in this species. Conclusion: The nucleotide sequences of blue-green algae and pathogenic bacteria were compared using the MEGA_X program, and the results revealed a high percentage of similarity, reaching 95%, between species belonging to different families. Research has shown that pathogenic bacteria and cyanobacteria are 95% similar in gmr, 92% similar in bla and 77% in sul.