Daniel McKnight

Daniel McKnight

Daniel McKnight, smiling, wearing glasses

Bioinformatician in plant pathogen genomics and biosecurity

I use genomics and phylogenetics to work out which bacteria are threatening Australian crops. My PhD, with the University of Technology Sydney and NSW DPIRD, described four new Xanthomonas species and made the first Australian record of Xanthomonas cannabis.

Schematic family tree of Xanthomonas species from my research A simplified tree showing four new species I described, the first Australian record of Xanthomonas cannabis, and other Xanthomonas. Not to scale. X. rydalmerensis X. bundabergensis X. medicagonis X. tesorieronis X. cannabis other Xanthomonas
New species I described First Australian record Schematic, not to scale.

Current research

At NSW DPIRD I’m building, from scratch, software that designs and checks DNA-based diagnostic tests for plant pathogens. Fast, reliable tests are a first line of defence in biosecurity, but designing a good one by hand is slow and easy to get wrong. This pipeline automates the whole job, from raw sequences to a ranked shortlist of tests.

  1. Collect. Downloads and prepares the genome sequences for any organism you choose.
  2. Find targets. Locates the DNA regions that tell the target apart from its close relatives.
  3. Design. Generates every feasible test in those regions, aiming to catch as many known variants of the pathogen as possible. It covers PCR, qPCR, LAMP and CRISPR-based tests, plus multiplex tests that look for several targets at once and degenerate primers that tolerate natural variation in the DNA.
  4. Check quality. Screens every design for the things that make tests fail in the lab: primers that fold back on themselves or stick to each other, runs of repeated bases, and poorly matched melting temperatures.
  5. Report. Returns the best candidates, with statistics on how many variants of the species each one detects.

Already have primers? A second mode takes them as input, reports how well they perform and how many variants they capture, and suggests better primers aimed at the same region.

A graphical interface lets non-specialists run it without any bioinformatics, while adjustable thresholds and settings give experienced users full control.

Status
In development
Built by
NSW DPIRD, in collaboration with Deakin University
Funding
Australian Government Department of Agriculture, Fisheries and Forestry (DAFF)
Validation
Deakin University is testing the pipeline on three different pathogen systems

PhD research

Xanthomonas is a genus of bacteria that cause disease in plants, infecting several hundred crop species including rice, citrus and brassicas such as broccoli. Its name comes from the yellow pigment in its colonies. Many Australian isolates sat in culture collections for decades without a species name. In my PhD I sequenced and compared their genomes, tested whether they cause disease, and placed them on the tree.

The work covered bacterial genome assembly, phylogenetics, pangenomics, and the identification of virulence factors and genomic islands, backed up by plant infection assays.

  • Xanthomonas rydalmerensisIsolated from strawberry at Rydalmere in 1976. Carries few virulence-associated factors and did not cause disease in a pathogenicity assay.
  • Xanthomonas bundabergensisIsolated from strawberry at Bundaberg in 2010.
  • Xanthomonas medicagonisIsolated from lucerne (Medicago sativa) at Tatham in 1981.
  • Xanthomonas tesorieronisIsolated from strawberry at Rockley in 1976. Named for plant pathologist Leonard Tesoriero.
  • Xanthomonas cannabis in AustraliaFive historical isolates from zinnia and zucchini. Two lines of evidence, genomes and plant assays, show an emerging pathogen with genomic islands linked to virulence and drug resistance.

Publications

  1. Comparative genomics of ‘Xanthomonas cannabis’ reveals an emerging, diverse pathogen

    McKnight DJE, Clackson L, Wong-Bajracharya J, Webster J, Worden P, Snijders F, Okoh EB, Djordjevic SP, Chapman TA, Bogema DR. Microbial Genomics 11(11), 2025. doi:10.1099/mgen.0.001588

    Reports the presence of this pathogen in Australia and characterises how diverse it is.

  2. Xanthomonas bundabergensis sp. nov., Xanthomonas medicagonis sp. nov. and Xanthomonas tesorieronis sp. nov.: three members of group 1 Xanthomonas

    McKnight DJE, Wong-Bajracharya J, Okoh EB, Snijders F, Lidbetter F, Webster J, Haughton M, Djordjevic SP, Bogema DR, Chapman TA. International Journal of Systematic and Evolutionary Microbiology 75, 006686, 2025. doi:10.1099/ijsem.0.006686

    Describes three new species from four historical Australian isolates.

  3. Xanthomonas rydalmerensis sp. nov., a non-pathogenic member of Group 1 Xanthomonas

    McKnight DJE, Wong-Bajracharya J, Okoh EB, Snijders F, Lidbetter F, Webster J, Haughton M, Darling AE, Djordjevic SP, Bogema DR, Chapman TA. International Journal of Systematic and Evolutionary Microbiology 74(3), 006294, 2024. doi:10.1099/ijsem.0.006294

    Describes a new species from strawberry and shows it is non-pathogenic.

  4. Phylogenomic Sequence Analysis of Xanthomonas citri Pathovars anacardii and mangiferaeindicae Reveals a Diversity of Pathogenicity Factors

    Okoh EB, Wong-Bajracharya J, McKnight DJE, Snijders F, Webster J, Riegler M, Bogema DR, Chapman TA. Plant Pathology. doi:10.1111/ppa.14130

    Compares the genomes of the bacteria behind mango and cashew bacterial black spot to find the genes that help them infect plants.

Full list and citation counts on Google Scholar and ORCID.

Experience and education

Employment

2025 to present
BioinformaticianNew South Wales Department of Primary Industries and Regional Development (DPIRD)

Building software from scratch that automates the design and testing of diagnostic assays for plant pathogens.

2021 to 2025
Technical assistantBiotechnology and Plants laboratories, NSW DPIRD

Worked in high-throughput, NATA-accredited laboratories, learning what makes a diagnostic result reliable and what data a lab needs from an analysis.

2020 to 2021
Electrical contractorDevika

Diagnosed and repaired electrical faults, building the methodical troubleshooting habits I now use to debug analysis pipelines.

2020
Summer casual researcherYu Research Group

Began computational biophysics research, teaching myself Python and Bash to analyse scientific data.

2018
Biochemistry internVenus Shell Systems

Gained hands-on laboratory biochemistry experience, grounding me in how the data I now analyse is generated.

2015 to 2020
Sales assistantJaycar Electronics, Wollongong

Explained technical electronics to customers in plain language, a skill I use to make bioinformatics accessible to non-specialists.

Education

2021 to 2025
Doctor of PhilosophyCollaborative project between the University of Technology Sydney and NSW DPIRD
2020
Bachelor of Science (Honours), first classUniversity of Wollongong
2016 to 2019
Bachelor of Science, major in BiotechnologyUniversity of Wollongong

Awards and certificates

2024
Store and handle dangerous goods and hazardous substances (TLID0021)
2023
Vice-Chancellor’s Conference FundUniversity of Technology Sydney
2021
Australian Research Council (ARC) Linkage scholarship and stipend

Skills

Genomics and phylogenetics. Bacterial genome assembly, phylogenetics, genomic and pangenomic analysis, virulence factor and genomic island identification.

Programming and pipelines. Python, R and GNU Bash from five years of bioinformatics and computational biophysics research. I build automated pipelines with QC checkpoints, error handling and reproducibility.

Molecular diagnostics. Developing and validating qPCR primers, including an assay for pre-symptomatic detection of Xanthomonas campestris in broccoli.

Data analysis. Data manipulation and visualisation for published papers and my thesis.

Collaboration. Coordinated research across 12 co-authors from four institutes. I taught myself computational biophysics and bioinformatics coming from a biological science background.

Community involvement

2023 to present
VolunteerIllawarra Potters Inc., a community pottery studio
2020
Student representativeSMAH honours course, University of Wollongong
2019
Learning Labs volunteerTaught high school students in summer STEM classes, University of Wollongong
2018 to 2019
BioNetSocial and support network for biology students, University of Wollongong

Contact

I’m looking to keep contributing to Australian biosecurity. If you work on plant disease, diagnostics or pathogen genomics, get in touch.