https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 Genomic epidemiology of severe community-onset Acinetobacter baumannii infection https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:35705 Acinetobacter baumannii causes severe, fulminant, community-acquired pneumonia (CAP) in tropical and subtropical regions. We compared the population structure, virulence and antimicrobial resistance determinants of northern Australian community-onset A. baumannii strains with local and global strains. We performed whole-genome sequencing on 55 clinical and five throat colonization A. baumannii isolates collected in northern Australia between 1994 and 2016. Clinical isolates included CAP (n=41), healthcare-associated pneumonia (n=7) and nosocomial bloodstream (n=7) isolates. We also included 93 publicly available international A. baumannii genome sequences in the analyses. Patients with A. baumannii CAP were almost all critically unwell; 82 % required intensive care unit admission and 18 % died during their inpatient stay. Whole-genome phylogenetic analysis demonstrated that community-onset strains were not phylogenetically distinct from nosocomial strains. Some non-multidrug-resistant local strains were closely related to multidrug-resistant strains from geographically distant locations. Pasteur sequence type (ST)10 was the dominant ST and accounted for 31/60 (52 %) northern Australian strains; the remainder belonged to a diverse range of STs. The most recent common ancestor for ST10 was estimated to have occurred in 1738 (95 % highest posterior density, 1626–1826), with evidence of multiple introduction events between Australia and Southeast Asia between then and the present day. Virulence genes associated with biofilm formation and the type 6 secretion system (T6SS) were absent in many strains, and were not associated with in-hospital mortality. All strains were susceptible to gentamicin and meropenem; none carried an AbaR resistance island. Our results suggest that international dissemination of A. baumannii is occurring in the community on a contemporary timescale. Genes associated with biofilm formation and the T6SS may not be required for survival in community niches. The relative contributions of host and bacterial factors to the clinical severity of community-onset A. baumannii infection require further investigation.]]> Wed 15 Dec 2021 16:09:07 AEDT ]]> AadT, a New Weapon in Acinetobacter's Fight Against Antibiotics https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:50476 Tue 14 Nov 2023 15:04:31 AEDT ]]> Whole-genome sequencing to differentiate relapse from reinfection in community-onset bacteremic Acinetobacter baumannii pneumonia https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:45198 Acinetobacter baumannii pneumonia recurred in 3 of 30 (10%) patients followed prospectively, all with ongoing hazardous alcohol intake, 3-56 months after initial pneumonia. Paired isolates underwent whole-genome sequencing. Phylogenetic analysis showed that recurrence strains were all distinct from preceding strains, indicating reinfection in susceptible individuals rather than relapse.]]> Tue 14 Nov 2023 14:44:58 AEDT ]]> Aptamer conjugated indium phosphide quantum dots with a zinc sulphide shell as photoluminescent labels for acinetobacter baumannii https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:45374 Acinetobacter baumannii is a remarkable microorganism known for its diversity of habitat and its multi-drug resistance, resulting in hard-to-treat infections. Thus, a sensitive method for the identification and detection of Acinetobacter baumannii is vital. However, current methods used for the detection of pathogens have not improved in the past decades and suffer from long process times and low detection limits. A cheap, quick, and easy detection mechanism is needed. In this work, we successfully prepared indium phosphide quantum dots with a zinc sulphide shell, conjugated to a targeting aptamer ligand, to specifically label Acinetobacter baumannii. The system retained both the photophysical properties of the quantum dots and the folded structure and molecular recognition function of the aptamer, therefore successfully targeting Acinetobacter baumannii. Confocal microscopy and transmission electron microscopy showed the fluorescent quantum dots surrounding the Acinetobacter baumannii cells confirming the specificity of the aptamer conjugated to indium phosphide quantum dots with a zinc sulphide shell. Controls were undertaken with a different bacteria species, showing no binding of the aptamer conjugated quantum dots. Our strategy offers a novel method to detect bacteria and engineer a scalable platform for fluorescence detection, therefore improving current methods and allowing for better treatment.]]> Thu 27 Oct 2022 12:35:19 AEDT ]]> Identification of a novel LysR family transcriptional regulator controlling acquisition of sulfur sources in Acinetobacter baumannii https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:50201 Fri 07 Jul 2023 09:49:40 AEST ]]>