Ruth Milne Hall

Background

Ruth Milne Hall was born on August 6, 1945 in Sydney, New South Wales, Australia.

Education

Hall attended Hornsby Girls High School, graduated from the University of Sydney with a Bachelor of Science degree (1966) and a Master of Science degree (1968), and then took up a scholarship for Doctor of Philosophy degree on bacterial genetics in the MRC Microbial Genetics Unit at the University of Edinburgh (awarded 1971).

Career

She then joined the research staff at the CSIRO Molecular and Cell Biology Unit., where she worked on integrons and antibiotic resistance genes. . After her research unit at CSIRO was closed (2003) she returned to the University of Sydney, where her research on the molecular genetics and genomics of bacterial antibiotic resistance has identified further mechanisms for gene transfer between gram negative bacteria. Hall has investigated the role of mobile genetic elements in the development of multiple antibiotic resistance and in bacterial evolution using different Gram negative pathogens including Escherichia coli, Salmonella enterica, Klebsiella pneumoniae and Acinetobacter baumanni.

Hall’s work has characterized a variety of mobile elements, including plasmids, genomic islands, transposons, gene cassettes and integrons. Gene cassettes are mobile genetic units each carrying only one gene which can be readily transferred into and between larger, stable genetic backbones called integrons that are responsible for moving the cassettes. The integron is also responsible for expression of the genes in cassettes.

This exchange of genes between different bacteria enables rapid emergence of resistance under selection pressure of antibiotics. Her recent work has identified large antibiotic resistance gene clusters, including genomic resistance islands in Salmonella, in Klebsiella pneumonia and in Acinetobacter baumanni and examines their evolution. Multiple antibiotic resistance in Acinetobacter baumanni is now being tracked using whole genome analysis.

Spread of resistance between individuals is an increased risk among hospitalized and immunosuppressed patients with Hall’s work identifying the role of commensal bacteria, including E.coli in the human colon in spread of genes. Resistance genes can also reach the human food chain through subtherapeutic antibiotic use as growth promotants in animal production, with Hall contributing to JETACAR (Joint Expert Advisory Committee on Antibiotic Resistance), which, in 2000, developed Australian Government policy on antibiotic use in agriculture. The risks of the rise of “superbugs” from the gene exchange processes described by Hall are recognized internationally as a threat to human health (WHO report on antibiotic resistance, May 2014).

Achievements

• In 2014 she was inducted into the National Health and Medical Research Council Hall of Fame.