Exploring the antimicrobial potency of gallium nanoparticles to combat Acinetobacter baumannii

Author: Dimpy Sheth

Sheth, Dimpy, 2024 Exploring the antimicrobial potency of gallium nanoparticles to combat Acinetobacter baumannii, Flinders University, College of Medicine and Public Health

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Acinetobacter baumannii is becoming a significant global health concern due to its rise in hospital-acquired infections and its ability to resist multiple drugs. Infections caused by this bacterium can be deadly, with fatality rates ranging from 30% to 60%. A. baumannii can form biofilms, survive on medical surfaces, and develop resistance to antibiotics, making new treatment strategies essential. The bacterium has ability to form biofilms, acquire iron, and produce virulence factors contribute to its strength. Its protective capsule helps it evade antibiotics and the immune system, allowing it to thrive in various environments. The lack of new antimicrobial agents has led researchers to explore alternative approaches like using metals for antibacterial purposes. Gallium, a metal element from Group 13 of the periodic table, shows promise as an antimicrobial agent due to its unique properties such as low melting point and reactivity. Recent studies suggest that gallium-based technologies, including gallium liquid metal, can effectively combat drug-resistant bacteria like multidrug resistant bacteria. However, challenges remain in utilizing gallium safely and effectively in medical settings. Despite these challenges, gallium-based strategies offer a new avenue for combating antibiotic-resistant bacteria like MDR A. baumannii. This study aimed to develop and assess the efficacy of gallium based liquid metal nanoparticles (GaLM NPs) against multidrug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa. The overarching hypothesis posits that GaLM NPs will demonstrate significant antibacterial activity against these resistant A. baumannii strains and will effectively reduce biofilm formation. The study is structured around several goals. Developing innovative agents such as GaLM NPs to counteract the ongoing threat posed by A. baumannii, which is resistant to several drugs, is the main objective. GaLM NPs are first synthesised and then thoroughly characterised to determine their physicochemical properties. The second objective is to assess the antibacterial efficacy of GaLM NPs against strains of A. 3 baumannii, with a particular emphasis on their capacity to impede bacterial growth and destabilise formed biofilms. In-depth biofilm assays are used to evaluate this, offering information about the nanoparticles' mode of action and potential as a novel class of antibacterial medicines. This research aims to provide an essential understanding of GaLM NPs interactions with bacterial pathogens, with a focus on the developing problem of antibiotic resistance. A thorough assessment of the nanoparticle’s antibacterial activity, capacity to destroy biofilms, and potential as a scalable remedy for getting cure from such infectious bacterial strains. The antimicrobial activity showed the inhibition to the agar by diffusing and creating the inhibition zones. Whereas the antibacterial activity was observed more in the A. baumannii ATCC 17978 which showed the higher resistance towards gallium liquid metal Nps. Moreover, the strains showed different OD in growth of biofilm as well due the presence of capsule in outer membrane of bacteria. This underscores the critical need for innovative treatment approaches in the face of increasing drug resistance.

Keywords: Acinetobacter baumannii, Hospital-acquired infections, Gallium, Antibiotic reistance, Antimicrobial agents

Subject: Medical Biotechnology thesis

Thesis type: Masters
Completed: 2024
School: College of Medicine and Public Health
Supervisor: Prof Melissa Brown