Iron and Manganese Azooxime Complexes as Anti-Microbial Agents Against Antibiotics Resistant Wild Bacteria From Hospital Drainage

Abstract

Antibiotic resistance is the never-ending war among medical researchers and microbial life forms. The extensive evolving potential of the microorganisms, in combination with improper usage, storage and disposal of the marketed antibiotics generated from natural or artificial sources, always calls for the need for novel antimicrobial agents with different modes of action. In this project, azo-oxime complexes of iron and manganese (seven in total) have been applied to wild multidrug-resistant pathogenic bacterial strains (isolated from sewage water of hospital). All complexes were inhibitory to bacterial strains present in the sewage water sample, which have been authenticated by a significant reduction in colony count upon their application to the microbial population of the water sample. Four of the most abundant colonies were isolated for further investigation about the bacterial characteristics, as well as to comprehend the molecular mechanism of action of these complexes to inhibit bacterial growth. Biochemical experiments in the form of the Catalase test, Coagulase test and lipase assay point towards the pathogenicity of bacterial strains. The strains were treated with various broad-spectrum antibiotics, namely, Penicillin G, Oxacillin, Cephalothin, Clindamycin, Erythromycin, Amoxyclav, Cefotaxime, Levofloxacin, Aztreonam, Imipenem, Amikacin, Ceftazidime, and found to be resistant against many of them, viz., Clindamycin, Ceftazidime, Erythromycin, Amoxyclav, and some others, thereby signifying that the molecular mechanism of action of the aforesaid complexes is multidimensional. These complexes were producing ROS in sufficient amounts that can cause lipid peroxidation, and subsequent damage to the bacterial cell membrane and translation machinery was found to be inhibited by RNA. Bacterial genomic DNA was also affected by the chelates, and this has been authenticated by the decreased genomic DNA concentration and presence of DNA debris on agarose gel electrophoresis of the DNA of bacterial cultures treated with the complexes.