ProfessorJonathan Iredell

Professor Iredell conducts basic and clinical research, combining his clinical expertise in critical care and long-standing research in molecular genetics. He develops and coordinates nationwide clinical trials related to life-threatening infections. His research covers critical infections and microbial ecology, especially in relation to transmissible antimicrobial resistance in bacteria.

Recent and contemporary projects include the study of bacterial load in septic shock (the BLISS study) and on transmissible resistance genetics in organisms such as E coli and Klebsiella sp, commonly implicated in life-threatening septic shock. Studies on the geographic distribution (Australia and global) and temporal variation of the antibiotic resistance gene pool are also underway (with Australian data implicating limited diversity in the transmissible antibiotic resistance gene pool). The team will exploit these data to develop diagnostic tests (using human blood) for key antibiotic resistance markers in Enterobacteriaceae, at the point of presentation to hospital with severe sepsis. His team seeks to better understand the associations between resistance genes conferring key phenotypes and their predominant means of spread, to help inform future surveillance and targeting of diagnostics.

Since antibiotic therapy is the cornerstone of managing critical infections, understanding the effects of antibiotics on the human microflora and on subsequent development of antibiotic resistance is crucial. Professor Iredell’s team is studying the impact of antibiotics on the microbial ecology of humans, and the correlations between antibiotics that cause greater disturbance of major bacteria in the microbiota and subsequent colonisation by antibiotic-resistant bacteria. New studies are investigating whether selective digestive tract decontamination with different types of antibiotics is associated with differing levels of disturbance of gut microflora and of antibiotic resistance, and the impact of such strategies on ICU outcomes.

Additional work includes specific manipulation of plasmid systems to reverse engineer antibiotic susceptibility in bacteria in vivo, and the targeting of specific bacterial clones with bacteriophage therapy and building a (globally-relevant) bank of probiotic plasmids that can protect the gut microflora.