Biography
My name is Desie Kasew Assefa. I completed my Bachelor of Science (BSc) in 2016, after which, I joined the University of Gondar, Ethiopia as a graduate assistant in the same year. Moreover, I perused a Master of Science (MSc) in medical microbiology. I worked in academic, research and community services at the university until I left for my PhD study. In 2024, I received University International post graduate Award (UIPA) scholarship at the UNSW and started my PhD under the superv...
Biography
My name is Desie Kasew Assefa. I completed my Bachelor of Science (BSc) in 2016, after which, I joined the University of Gondar, Ethiopia as a graduate assistant in the same year. Moreover, I perused a Master of Science (MSc) in medical microbiology. I worked in academic, research and community services at the university until I left for my PhD study. In 2024, I received University International post graduate Award (UIPA) scholarship at the UNSW and started my PhD under the supervision of Professor Mark Willcox and Dr Muhammad Yasir. My PhD research focuses on mixed species biofilm and whether these have increased resistance to antimicrobial peptides and their mimics.
Research Title: Does the formation of mixed species biofilms reduce sensitivity to antimicrobial peptides and their mimics?
Supervisors: Professor Mark Willcox & Dr Muhammad Yasir
Research Abstract
Biofilms are agglomerations of bacteria attached to a surface and encased in self-produced polymer matrices. Biofilms account for at least 50% of all hospital-acquired infections. Biofilms, such as those found in diabetic foot ulcers, cystic fibrosis and bacterial vaginosis, commonly contain mixed species communities.
Biofilms allow bacteria to be up to 1000 times more resistant to biocides (disinfectants, antibiotics) and our immune system, making them very difficult to eradicate. However, the AMPs LL-37, indolicidin, and human b-defensins 2 and 3 inhibit biofilm formation by S. aureus and P. aeruginosa at concentrations lower than those required to kill planktonic cells. Importantly, the AMPs LL-37, peptide 1018, and peptides designed by our group, melimine and Mel4, can reduce the amount of preformed biofilms. The inhibition of biofilm by AMPs can be via several mechanisms including influencing quorum sensing and decreasing the expression of genes involved in biofilm matrix formation. Melimine, Mel4 and RK758 kill biofilm bacteria by disrupting cell membranes resulting in release of intracellular contents as previous studies indicated on single species biofilms. It is not known whether mixed species biofilms can be affected in a similar manner.
