The increasing prevalence of multidrug-resistant (MDR) pathogens and biofilm-associated infections represents a major challenge for modern medicine. This thesis aimed to establish and apply innovative Galleria mellonella infection models to investigate microbial pathogenesis and evaluate novel antimicrobial strategies in clinically relevant contexts. An implant biofilm model using clinically relevant expanded polytetrafluoroethylene (ePTFE) material was developed to study biofilm formation by Staphylococcus aureus and Enterococcus faecalis. The model enabled in vivo assessment of biofilm development and antimicrobial treatment. Rifampicin alone or in combination with vancomycin significantly reduced bacterial burden and improved larval survival, demonstrating the utility of the model for preclinical biofilm research. In addition, a G. mellonella gut colonization model was established to study intestinal colonization by Enterobacteriaceae, including Klebsiella pneumoniae and Escherichia coli. This model enabled evaluation of bacteriophage therapy, which significantly reduced K. pneumoniae colonization and demonstrated its potential as a targeted alternative to antibiotics. Furthermore, a novel lytic bacteriophage, vbKpUKJ₂, was isolated from hospital wastewater and characterized. The phage showed strong lytic activity against clinical K. pneumoniae isolates and lacked antibiotic resistance genes, supporting its potential for therapeutic applications. Overall, this work establishes Galleria mellonella as a scalable and ethically favorable in vivo platform for studying biofilm infections, gut colonization, and phage-based antimicrobial strategies, bridging the gap between in vitro studies and vertebrate infection models.
Kamran Mirza (Thu,) studied this question.