Publications by authors named "Patrick N A Harris"

Purpose: Klebsiella pneumoniae is a common cause of hospital- and community-acquired infection and can readily acquire multiple antimicrobial resistance determinants leading to poor health outcomes. We define the contemporary burden of disease, risk factors for antimicrobial resistance, and poor health outcomes for patients with K. pneumoniae bloodstream infection (Kp-BSI).

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Background: Fusobacterium species are anaerobic Gram-negative bacilli which are uncommon causes of bloodstream infection (BSI). This genus commonly colonises the gastrointestinal tract and can result in significant morbidity.

Methods: All blood cultures with growth of Fusobacterium species among residents of Queensland, Australia (population ≈ 5 million) were retrospectively identified over a 20-year period.

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Pathogen genomic surveillance in healthcare has the potential to enhance patient safety by detecting outbreaks earlier, thereby reducing morbidity and mortality. Despite benefits, there are barriers to adoption, including cost, expertise, and lack of standardized methodologies and incentives. This commentary advocates for 1) investment from healthcare payors, public health, and regulatory bodies and 2) additional research on genomic surveillance for improving patient outcomes and reducing infections.

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Background: Although Providencia species are recognised as important causes of bloodstream infections (BSI), their epidemiology is not well defined due to their infrequent occurrence. Our objective was to determine the overall incidence, determinants, and outcomes of Providencia species BSI, and compare the epidemiology of P. stuartii and P.

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Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Time to receive effective therapy is a primary determinant of mortality in patients with sepsis. Blood culture is the reference standard for the microbiological diagnosis of bloodstream infections, despite its low sensitivity and prolonged time to receive a pathogen detection.

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Article Synopsis
  • Enterobacterales bloodstream infections (E-BSI) pose a significant health threat to children in Queensland, Australia, with a notable rise in infection rates observed from 2000 to 2019.
  • A total of 1980 E-BSI cases were recorded, leading to an increase in the standardized incidence rate from 7.3 to 12.9 cases per 100,000 child years, with E. coli and Salmonella sp. being the most common pathogens.
  • The study highlights the growing antimicrobial resistance, particularly in E. coli, and emphasizes the need for including children in clinical trials for more effective treatment options.
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We describe the demographics, clinical and molecular epidemiology of extended-spectrum β-lactamase (ESBL) Escherichia coli bloodstream infections (BSI) in Central Australia. All ESBL-producing E. coli bloodstream isolates from January 2018 to December 2020 were retrospectively identified.

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, the causative agent of melioidosis, is highly genetically recombinant, resulting in significant genomic diversity. Multiple virulence factors have been associated with specific disease presentations. To date, there are limited data relating to genomic diversity and virulence factors associated with melioidosis cases in North Queensland, Australia.

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  • A 3-year study in five Australian children's hospitals found that Gram-negative bloodstream infections (GNBSIs) significantly affect children under 5, often occurring in those with existing health issues and central venous catheters.
  • Out of 931 infection episodes involving 818 children, community onset was common, and 71% of cases involved antibiotic-resistant pathogens, particularly from the Enterobacterales family.
  • The study highlighted a 3% in-hospital mortality rate, with infections involving third-generation cephalosporin resistant Enterobacterales linked to higher mortality rates, suggesting a need for improved prevention and treatment strategies.
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Background: Evidence about the clinical impact of rapid diagnostic tests (RDTs) for the diagnosis of bloodstream infections is limited, and whether RDT are superior to conventional blood cultures (BCs) embedded within antimicrobial stewardship programs (ASPs) is unknown.

Methods: We performed network meta-analyses using results from studies of patients with bloodstream infection with the aim of comparing the clinical impact of RDT (applied on positive BC broth or whole blood) to conventional BC, both assessed with and without ASP with respect to mortality, length of stay (LOS), and time to optimal therapy.

Results: Eighty-eight papers were selected, including 25 682 patient encounters.

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Article Synopsis
  • * A study of 58 NMEC isolates revealed significant genetic diversity, with key prevalent sequence types identified, but no single virulence gene profile was universally found across all samples.
  • * Patients experiencing recurring infections despite antibiotic treatment showed severe gut dysbiosis, suggesting that the NMEC strain may persist in gut flora, leading to potential reinfection.
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Background: Although Proteus species are occasional causes of serious infections, their epidemiology has not been well defined. The objective was to describe the overall and species-specific occurrence and determinants of Proteus species bloodstream infection (BSI) in a large Australian population.

Methods: All Queensland residents with Proteus species BSI identified within the publicly funded healthcare system between 2000 and 2019 were included.

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  • This study investigates the relationship between time to positivity (TTP) of blood cultures and the risk of death within 30 days for patients with bloodstream infections (BSI) in Queensland, Australia, over 19 years.
  • The research included 88,314 patients and found that a shorter TTP (especially under 10 hours) was linked to a higher risk of death, with specific bacteria like Staphylococcus aureus and Pseudomonas species showing even greater death risks.
  • The findings emphasize that TTP is a significant factor in mortality risk for patients suffering from bloodstream infections, highlighting the need for timely medical intervention.
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  • The rise of sequence type (ST) 45 methicillin-resistant Staphylococcus aureus (MRSA) has been notable in the past decade, but its causes are not fully understood.
  • Research involving phylogenetic analysis of ST45 MRSA from Australia and globally identified a unique lineage with multidrug resistance, particularly in Australia and Singapore.
  • The study found that the qacA gene, acquired in the late 1990s, enhances tolerance to chlorhexidine, indicating that both antimicrobial resistance and qacA are key to the establishment of ST45 MRSA.
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Purpose: Early recognition and effective treatment of sepsis improves outcomes in critically ill patients. However, antibiotic exposures are frequently suboptimal in the intensive care unit (ICU) setting. We describe the feasibility of the Bayesian dosing software Individually Designed Optimum Dosing Strategies (ID-ODS™), to reduce time to effective antibiotic exposure in children and adults with sepsis in ICU.

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Background: Bloodstream infections (BSIs) caused by carbapenem-resistant Enterobacterales (CRE) are a global health concern. Rapid identification of CRE may improve patient outcomes and reduce inappropriate antibiotic prescription. The use of risk-scoring tools (RSTs) can be valuable for optimizing the decision-making process for empirical antibiotic therapy of suspected CRE bacteraemia.

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Existing tools for phylogeographic and epidemiological visualisation primarily provide a macro-geographic view of epidemic and pandemic transmission events but offer little support for detailed investigation of outbreaks in healthcare settings. Here, we present HAIviz, an interactive web-based application designed for integrating and visualising genomic epidemiological information to improve the tracking of healthcare-associated infections (HAIs). HAIviz displays and links the outbreak timeline, building map, phylogenetic tree, patient bed movements, and transmission network on a single interactive dashboard.

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Background: Clinical trials of treatments for serious infections commonly use the primary endpoint of all-cause mortality. However, many trial participants survive their infection and this endpoint may not truly reflect important benefits and risks of therapy. The win ratio uses a hierarchical composite endpoint that can incorporate and prioritize outcome measures by relative clinical importance.

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We aimed to evaluate the performance of Oxford Nanopore Technologies (ONT) sequencing from positive blood culture (BC) broths for bacterial identification and antimicrobial susceptibility prediction. Patients with suspected sepsis in four intensive care units were prospectively enrolled. Human-depleted DNA was extracted from positive BC broths and sequenced using ONT (MinION).

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Background: A prompt diagnosis of bacteraemia and sepsis is essential. Markers to predict the risk of persistent bacteraemia and metastatic infection are lacking. SeptiCyte RAPID is a host response assay stratifying patients according to the risk of infectious vs sterile inflammation through a scoring system (SeptiScore).

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Objectives: The objective of this systematic review and meta-analysis was to estimate the global prevalence of multi-drug resistant (MDR) Pseudomonas aeruginosa causing ventilator-associated pneumonia (VAP).

Methods: The systematic search was conducted in four databases. Original studies describing MDR P.

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Objectives: This population-based study aimed to investigate the risk factors and effect of extended-spectrum beta-lactamase (ESBL) production on clinical outcomes in Escherichia coli bloodstream infection (BSI) patients.

Methods: The study population was defined as patients aged ≥15 years with E. coli BSI in Queensland, Australia, from 2000 to 2019.

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Background: Persistent Staphylococcus aureus bacteremia is associated with metastatic infection and adverse outcomes, whereas gram-negative bacteremia is normally transient and shorter course therapy is increasingly advocated for affected patients. Whether the prolonged detection of pathogen DNA in blood by culture-independent systems could have prognostic value and guide management decisions is unknown.

Methods: We performed a multicenter, prospective, observational study on 102 patients with bloodstream infection (BSI) to compare time to bloodstream clearance according to T2 magnetic resonance and blood cultures over a 4-day follow-up.

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