ORCID Profile
0000-0002-7920-5855
Current Organisation
Murdoch University
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Publisher: Elsevier BV
Date: 11-2018
DOI: 10.1016/J.VETMIC.2018.10.010
Abstract: Streptococcus suis is a major zoonotic pathogen that causes severe disease in both humans and pigs. Australia's pig herd has been quarantined for over 30 years, however S. suis remains a significant cause of disease. In this study, we investigated S. suis from 148 cases of clinical disease in pigs from 46 pig herds over a period of seven years, to determine the level of genetic difference from international isolates that may have arisen over the 30 years of separation. Isolates underwent whole genome sequencing, genome analysis and antimicrobial susceptibility testing. Data was compared at the core genome level to clinical isolates from overseas. Results demonstrated five predominant multi-locus sequence types and two major cps gene types (cps2 and 3). At the core genome level Australian isolates clustered predominantly within one large clade consisting of isolates from the UK, Canada and North America. A small proportion of Australian swine isolates (5%) were phylogenetically associated with south-east Asian and UK isolates, many of which were classified as causing systemic disease, and derived from cases of human and swine disease. Based on this dataset we provide a comprehensive outline of the current S. suis clones associated with disease in Australian pigs and their global context, with the main finding being that, despite three decades of separation, Australian S. suis are genomically similar to overseas strains. In addition, we show that ST1 clones carry a constellation of putative virulence genes not present in other Australian STs.
Publisher: Oxford University Press (OUP)
Date: 24-04-2021
DOI: 10.1093/JAC/DKAB107
Abstract: Surveillance of antimicrobial resistance (AMR) is critical to reducing its wide-reaching impact. Its reliance on s le size invites solutions to longstanding constraints regarding scalability. A robotic platform (RASP) was developed for high-throughput AMR surveillance in accordance with internationally recognized standards (CLSI and ISO 20776-1:2019) and validated through a series of experiments. Experiment A compared RASP’s ability to achieve consistent MICs with that of a human technician across eight replicates for four Escherichia coli isolates. Experiment B assessed RASP’s agreement with human-performed MICs across 91 E. coli isolates with a erse range of AMR profiles. Additionally, to demonstrate its real-world applicability, the RASP workflow was then applied to five faecal s les where a minimum of 47 E. coli per animal (239 total) were evaluated using an AMR indexing framework. For each drug–rater–isolate combination in Experiment A, there was a clear consensus of the MIC and deviation from the consensus remained within one doubling dilution (the exception being gentamicin at two dilutions). Experiment B revealed a concordance correlation coefficient of 0.9670 (95% CI: 0.9670–0.9670) between the robot- and human-performed MICs. RASP’s application to the five faecal s les highlighted the intra-animal ersity of gut commensal E. coli, identifying between five and nine unique isolate AMR phenotypes per s le. While adhering to internationally accepted guidelines, RASP was superior in throughput, cost and data resolution when compared with an experienced human technician. Integration of robotics platforms in the microbiology laboratory is a necessary advancement for future One Health AMR endeavours.
Publisher: American Society for Microbiology
Date: 04-2020
DOI: 10.1128/AEM.02765-19
Abstract: C ylobacter is one of the most common causes of gastroenteritis in humans, with infections frequently resulting from exposure to undercooked poultry products. Although human illness is typically self-limiting, a minority of cases do require antimicrobial therapy. Ensuring that C ylobacter originating from meat chickens does not acquire resistance to fluoroquinolones is therefore a valuable outcome for public health. Australia has never legalized the use of fluoroquinolones in commercial chickens and until now fluoroquinolone-resistant C ylobacter has not been detected in the Australian poultry. This structured survey of meat chickens derived from all major Australian producers describes the unexpected emergence of fluoroquinolone resistance in C ylobacter jejuni and C. coli . Genetic characterization suggests that these isolates may have evolved outside the Australian poultry sector and were introduced into poultry by humans, pest species, or wild birds. The findings dramatically underline the critical role of biosecurity in the overall fight against antimicrobial resistance.
No related grants have been discovered for Alec Truswell.