ORCID Profile
0000-0001-8654-3601
Current Organisation
James Cook University
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Publisher: Wiley
Date: 22-06-2011
DOI: 10.1111/J.1751-0813.2011.00794.X
Abstract: Queensland has the highest incidence of Q fever in Australia. The aim of this study was to undertake a cross-sectional seroprevalence survey of Coxiella burnetii, the causative agent of Q fever, in beef cattle in Queensland. Serum s les were tested by ELISA for both phase II and phase I antigens of the organism using an Australian isolate. Blood s les were collected at an abattoir that processes beef cattle originating from northern and north-western Queensland, in addition to blood s les taken from beef cattle across Queensland as part of a second survey. Seropositivity was 16.8% (95% confidence interval 16.7-16.8%). Evidence of C. burnetii infection in beef cattle has public health implications for occupational exposure of primary producers and veterinarians and for the proximity of beef cattle properties to residential areas in regional Queensland. This study is the first known investigation of C. burnetii seroprevalence in beef cattle in Queensland and the first known use of an Australian C. burnetii isolate for screening using both phase II and phase I antigens.
Publisher: MDPI AG
Date: 16-12-2021
Abstract: In Escherichia coli, DNA replication termination is orchestrated by two clusters of Ter sites forming a DNA replication fork trap when bound by Tus proteins. The formation of a ‘locked’ Tus–Ter complex is essential for halting incoming DNA replication forks. However, the absence of replication fork arrest at some Ter sites raised questions about their significance. In this study, we examined the genome-wide distribution of Tus and found that only the six innermost Ter sites (TerA–E and G) were significantly bound by Tus. We also found that a single ectopic insertion of TerB in its non-permissive orientation could not be achieved, advocating against a need for ‘back-up’ Ter sites. Finally, examination of the genomes of a variety of Enterobacterales revealed a new replication fork trap architecture mostly found outside the Enterobacteriaceae family. Taken together, our data enabled the delineation of a narrow ancestral Tus-dependent DNA replication fork trap consisting of only two Ter sites.
Publisher: Wiley
Date: 20-09-2011
DOI: 10.1111/J.1751-0813.2011.00819.X
Abstract: OBJECTIVE Investigate the seroprevalence of the causative agent of Q fever, Coxiella burnetii in domestic dogs in the Townsville region, North Queensland, Australia. METHOD Blood s les were collected from dogs attending veterinary clinics for routine procedures. RESULTS An overall seropositivity of 21.8% (95% confidence interval (CI) 21.6-22.1%) was observed. A retrospective study of s les collected in the same region during 1984-85 was also performed, with an overall seropositivity of 16.0% (95% CI 15.9-16.2). CONCLUSION Evidence of C. burnetii infection in domestic dogs may have public health implications for dog owners, as well as veterinarians because of occupational exposure. This study is the first known investigation of C. burnetii seroprevalence in dogs in Queensland.
Publisher: American Society of Tropical Medicine and Hygiene
Date: 03-08-2016
Publisher: Elsevier BV
Date: 03-2012
DOI: 10.1016/J.VETMIC.2011.08.023
Abstract: Many animal species, including macropods, have the potential to act as atypical reservoirs of the causative agent of Q fever, Coxiella burnetii. The objective of this study was to determine the seroprevalence of C. burnetii in various macropod species in Australia. Competitive and indirect ELISAs were developed for the testing of macropod sera for antibodies to phase II and I C. burnetii antigens separately. A total of 500 macropod serum s les from selected species s led in eastern and western coastal states of Australia were screened for the presence of anti-C. burnetii antibodies. An overall seroprevalence of 20.8% (95% CI 20.8-20.9%) was observed with 30.4% (30.2-30.9%) in northern Queensland, 13.0% (12.9-13.1%) in southern Queensland, 7.1% (7.1-8.0%) in western Queensland and 22.8% (22.7-22.9%) in south-western Western Australia. These data indicated that macropods represented a potential reservoir for zoonotic transmission of C. burnetii to domestic animals and the human population.
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/J.DIAGMICROBIO.2013.07.009
Abstract: Melioidosis is caused by the Gram negative bacterium Burkholderia pseudomallei. The gold standard for diagnosis is culture, which requires at least 3-4 days obtaining a result, hindering successful treatment of acute disease. The existing indirect haemagglutination assay (IHA) has several disadvantages, in that approximately half of patients later confirmed culture positive are not diagnosed at presentation and a subset of patients are persistently seronegative. We have developed 2 serological assays, an enzyme-linked immunosorbent assay (ELISA), and a 2-dimensional immunoarray (2DIA), capable of detecting antibodies in patient sera from a greater proportion of IHA-negative patient subsets. The 2DIA format can distinguish between different LPS serotypes. Currently, the 2DIA has a sensitivity and specificity of 100% and 87.1%, respectively, with 100% of culture-positive, IHA-negative s les detected. The ELISA has a sensitivity and specificity of 86.2% and 93.5%, respectively, detecting 67% of culture-positive, IHA-negative s les. The ELISA and 2DIA tests described here are more rapid and reliable for serological testing compared to the existing IHA.
Publisher: Wiley
Date: 02-2008
DOI: 10.1002/IJC.23391
Abstract: The effect of the evolving HIV epidemic on cancer has been sparsely documented in Africa. We report results on the risk of cancer associated with HIV-1 infection using data from an ongoing study. A case-control analysis was used to estimate the relative risk (odds ratio, OR) of cancer types known to be AIDS defining: Kaposi's sarcoma (n = 333), non-Hodgkin lymphoma (NHL, n = 223) and cancers of the cervix (n = 1,586), and 11 cancer types possibly associated with HIV infection: Hodgkin lymphoma (n = 154), cancers of other anogenital organs (n = 157), squamous cell cancer of the skin (SCC, n = 70), oral cavity and pharynx (n = 319), liver (n = 83), stomach (n = 142), leukemia (n = 323), melanoma (n = 53), sarcomas other than Kaposi's (n = 93), myeloma (n = 189) and lung cancer (n = 363). The comparison group comprised 3,717 subjects with all other cancer types and 682 subjects with vascular disease. ORs were adjusted for age, sex (except cervical cancer), year of diagnosis, education and number of sexual partners. Significantly increased risks associated with HIV-1 infection were found for HIV/AIDS associated Kaposi's sarcoma (OR = 47.1, 95% CI = 31.9-69.8), NHL (OR = 5.9, 95% CI = 4.3-8.1) and cancer of the cervix (OR = 1.6, 95% CI = 1.3-2.0) Hodgkin's disease (OR = 1.6, 95% CI = 1.0-2.7), cancers of anogenital organs other than the cervix (OR = 2.2 95% CI = 1.4-3.3) and SCC (OR = 2.6, 95% CI = 1.4-4.9) were also significantly increased. No significant associations were found between HIV and any of the other cancers examined. Risks for HIV-related cancers are consistent with previous studies in Africa, and are lower when compared to those observed in developed countries.
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.MICRES.2017.08.014
Abstract: Biotin protein ligase (BirA) has been identified as an emerging drug target in Mycobacterium tuberculosis due to its essential metabolic role. Indeed, it is the only enzyme capable of covalently attaching biotin onto the biotin carboxyl carrier protein subunit of the acetyl-CoA carboxylase. Despite recent interest in this protein, there is still a gap in cost-effective high-throughput screening assays for rapid identification of mycobacterial BirA-targeting inhibitors. We present for the first time the cloning, expression, purification of mycobacterial GFP-tagged BirA and its application for the development of a high-throughput assay building on the principle of differential scanning fluorimetry of GFP-tagged proteins. The data obtained in this study reveal how biotin and ATP significantly increase the thermal stability (ΔT
Publisher: Springer US
Date: 27-11-2020
DOI: 10.1007/978-1-0716-0163-1_5
Abstract: Differential scanning fluorimetry is useful for a wide variety of applications including characterization of protein function, structure-activity relationships, drug screening, and optimization of buffer conditions for protein purification, enzyme activity, and crystallization. A limitation of classic differential scanning fluorimetry is its reliance on highly purified protein s les. This limitation is overcome through differential scanning fluorimetry of GFP-tagged proteins (DSF-GTP). DSF-GTP specifically measures the unfolding and aggregation of a target protein fused to GFP through its proximal perturbation effects on GFP fluorescence. As a result of this unique principle, DSF-GTP can specifically measure the thermal stability of a target protein in the presence of other proteins. Additionally, the GFP provides a unique in-assay quality control measure. Here, we describe the workflow, steps, and important considerations for executing a DSF-GTP experiment in a 96-well plate format.
Publisher: Cambridge University Press (CUP)
Date: 06-09-2011
DOI: 10.1017/S0950268811001828
Abstract: The state of Queensland has the highest incidence of Q fever in Australia. In recent years, there has been an increase in human cases where no contacts with the typical reservoir animals or occupations were reported. The aim of this study was to determine the seroprevalence of Coxiella burnetii in Australian native animals and introduced animals in northern and southeastern Queensland. Australian native marsupials s led included the brushtail possum ( Trichosurus vulpecula ) and common northern bandicoot ( Isoodon macrourus ). Introduced species s led included dingoes ( Canis lupus dingo ), cats ( Felis catus ), foxes ( Vulpes vulpes ) and pigs ( Sus scrofa ). Serum s les were tested by ELISA for both phase II and phase I antigens of the organism using an Australian isolate. The serological evidence of C. burnetii infection demonstrated in these species has public health implications due to their increasing movement into residential areas in regional Queensland. This study is the first known investigation of C. burnetii seroprevalence in these species in northern Queensland.
Publisher: Oxford University Press (OUP)
Date: 11-2007
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4AY02666G
Abstract: A simple quantitative in-gel detection system was developed for measuring production of biotin–protein conjugates using a green fluorescent streptavidin probe.
Publisher: Elsevier BV
Date: 06-2012
DOI: 10.1016/J.BIORTECH.2011.12.018
Abstract: Ametryn, which is a second generation herbicide, was introduced to a lab-scale MBR at a concentration of 1mg/L and a 20-40% removal was observed at HRT ranging from 7.8 to 15.6h for an average influent Ametryn concentration of 0.8 mg/L. Components of EPS (protein and carbohydrates) increased in the bioreactor and the observed biomass production reduced after the addition of Ametryn. In a batch study, GAC was added to MBR mixed liquor and removal of Ametryn via biodegradation and adsorption were measured. Five common bacterial colony types (Gram negative and positive bacilli and Gram negative cocci) were identified and three of these were resistant to Ametryn up to 5mg/L. GAC was found to be a very effective Ametryn adsorption medium and in some occasions Ametryn may have acted as a nutrient source for bacteria.
Publisher: MDPI AG
Date: 15-05-2023
DOI: 10.3390/IJMS24108802
Abstract: Over 1.2 million deaths are attributed to multi-drug-resistant (MDR) bacteria each year. Persistence of MDR bacteria is primarily due to the molecular mechanisms that permit fast replication and rapid evolution. As many pathogens continue to build resistance genes, current antibiotic treatments are being rendered useless and the pool of reliable treatments for many MDR-associated diseases is thus shrinking at an alarming rate. In the development of novel antibiotics, DNA replication is still a largely underexplored target. This review summarises critical literature and synthesises our current understanding of DNA replication initiation in bacteria with a particular focus on the utility and applicability of essential initiation proteins as emerging drug targets. A critical evaluation of the specific methods available to examine and screen the most promising replication initiation proteins is provided.
Publisher: Elsevier BV
Date: 06-2017
DOI: 10.1016/J.MICRES.2017.03.007
Abstract: Burkholderia pseudomallei (Bp) is the causative agent of melioidosis. The bacterium is responsible for 20% of community-acquired sepsis cases and 40% of sepsis-related mortalities in northeast Thailand, and is intrinsically resistant to aminoglycosides, macrolides, rifamycins, cephalosporins, and nonureidopenicillins. There is no vaccine and its diagnosis is problematic. Biotin protein ligase (BirA) which is essential for fatty acid synthesis has been proposed as a drug target in bacteria. Very few bacterial BirA have been characterized, and a better understanding of these enzymes is necessary to further assess their value as drug targets. BirA within the Burkholderia genus have not yet been investigated. We present for the first time the cloning, expression, purification and functional characterisation of the putative Bp BirA and orthologous B. thailandensis (Bt) biotin carboxyl carrier protein (BCCP) substrate. A GFP-tagged Bp BirA was produced and applied for the development of a high-throughput (HT) assay based on our differential scanning fluorimetry of GFP-tagged proteins (DSF-GTP) principle as well as an electrophoretic mobility shift assay. Our biochemical data in combination with the new HT DSF-GTP and biotinylation activity assay could facilitate future drug screening efforts against this drug-resistant organism.
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2RA22368F
Publisher: Elsevier BV
Date: 02-2013
DOI: 10.1016/J.DIAGMICROBIO.2012.10.011
Abstract: Melioidosis is caused by the Gram-negative bacterium Burkholderia pseudomallei. The gold standard for diagnosis is culture, which requires at least 3-4 days to obtain a result, hindering successful treatment of acute disease. An indirect haemagglutination assay (IHA) is often used but lacks sensitivity. Approximately half of patients later confirmed culture positive are not detected by IHA at presentation and a subset of patients persistently continue to be IHA negative. More rapid and reliable serologic testing for melioidosis is essential and will improve diagnosis and patient outcome. We have developed an ELISA and a quantitative immuno-polymerase chain reaction assay capable of detecting melioidosis-specific antibodies and demonstrate their validity with IHA-negative sera from patients with melioidosis. These new sensitive assays are based upon a secreted antigenic fraction from B. pseudomallei and will be ideal for the diagnosis of melioidosis in patients in nonendemic regions returning from endemic tropical areas and for seroepidemiologic surveys.
Publisher: Wiley
Date: 22-06-2011
DOI: 10.1111/J.1751-0813.2011.00794.X
Abstract: Queensland has the highest incidence of Q fever in Australia. The aim of this study was to undertake a cross-sectional seroprevalence survey of Coxiella burnetii, the causative agent of Q fever, in beef cattle in Queensland. Serum s les were tested by ELISA for both phase II and phase I antigens of the organism using an Australian isolate. Blood s les were collected at an abattoir that processes beef cattle originating from northern and north-western Queensland, in addition to blood s les taken from beef cattle across Queensland as part of a second survey. Seropositivity was 16.8% (95% confidence interval 16.7-16.8%). Evidence of C. burnetii infection in beef cattle has public health implications for occupational exposure of primary producers and veterinarians and for the proximity of beef cattle properties to residential areas in regional Queensland. This study is the first known investigation of C. burnetii seroprevalence in beef cattle in Queensland and the first known use of an Australian C. burnetii isolate for screening using both phase II and phase I antigens.
Publisher: MDPI AG
Date: 03-03-2023
DOI: 10.3390/BIOS13030338
Abstract: Accurate temperature control within biological and chemical reaction s les and instrument calibration are essential to the diagnostic, pharmaceutical and chemical industries. This is particularly challenging for microlitre-scale reactions typically used in real-time PCR applications and differential scanning fluorometry. Here, we describe the development of a simple, inexpensive ratiometric dual fluorescent protein temperature biosensor (DFPTB). A combination of cycle three green fluorescent protein and a monomeric red fluorescent protein enabled the quantification of relative temperature changes and the identification of temperature discrepancies across a wide temperature range of 4–70 °C. The maximal sensitivity of 6.7% °C−1 and precision of 0.1 °C were achieved in a biologically relevant temperature range of 25–42 °C in standard phosphate-buffered saline conditions at a pH of 7.2. Good temperature sensitivity was achieved in a variety of biological buffers and pH ranging from 4.8 to 9.1. The DFPTB can be used in either purified or mixed bacteria-encapsulated formats, paving the way for in vitro and in vivo applications for topologically precise temperature measurements.
Publisher: Springer Science and Business Media LLC
Date: 02-03-2007
Publisher: Oxford University Press (OUP)
Date: 09-12-2017
Abstract: Acute rheumatic fever and rheumatic heart disease (ARF/RHD) have long been described as autoimmune sequelae of Streptococcus pyogenes or group A streptococcal (GAS) infection. Both antibody and T-cell responses against immunodominant GAS virulence factors, including M protein, cross-react with host tissue proteins, triggering an inflammatory response leading to permanent heart damage. However, in some ARF/RHD-endemic regions, throat carriage of GAS is low. Because Streptococcus dysgalactiae subspecies equisimilis organisms, also known as β-hemolytic group C streptococci and group G streptococci (GGS), also express M protein, we postulated that streptococci other than GAS may have the potential to initiate or exacerbate ARF/RHD. Using a model initially developed to investigate the uniquely human disease of ARF/RHD, we have discovered that GGS causes interleukin 17A/interferon γ-induced myocarditis and valvulitis, hallmarks of ARF/RHD. Remarkably the histological, immunological, and functional changes in the hearts of rats exposed to GGS are identical to those exposed to GAS. Furthermore, antibody cross-reactivity to cardiac myosin was comparable in both GGS- and GAS-exposed animals, providing additional evidence that GGS can induce and/or exacerbate ARF/RHD.
Publisher: Springer US
Date: 27-11-2020
DOI: 10.1007/978-1-0716-0163-1_10
Abstract: The electrophoretic mobility shift assay (EMSA) is commonly used for the study of nucleic acid-binding proteins. The technique can be used to demonstrate that a protein is binding to RNA or DNA through visualization of a shift in electrophoretic mobility of the nucleic acid band. A major disadvantage of the EMSA is that it does not always provide an absolute certitude that the band shift is due to the protein under scrutiny, as contaminants in the s le could also cause the band shift. Here we describe a variation of the standard EMSA allowing to visualize with added certitude, the co-localized band shifts of a GFP-tagged protein binding to its cognate nucleic acid target sequence stained with an intercalator, such as GelRed. Herein, we present an illustrative protocol of this useful technique called GFP-EMSA along with specific notes on its advantages and limitations.
Publisher: Microbiology Society
Date: 08-2015
DOI: 10.1099/JMM.0.000098
Publisher: Elsevier BV
Date: 03-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8CC00090E
Abstract: Selective protein unfolding was combined with high-throughput differential scanning fluorimetry of GFP-tagged proteins for the identification of irreversible enzyme inhibitors.
Publisher: Elsevier BV
Date: 08-2023
Publisher: Cold Spring Harbor Laboratory
Date: 21-07-2021
DOI: 10.1101/2021.07.20.453168
Abstract: In Escherichia coli , DNA replication termination is orchestrated by two clusters of Ter sites forming a DNA replication fork trap when bound by Tus proteins. The formation of a ‘locked’ Tus- Ter complex is essential for halting incoming DNA replication forks. However, the absence of replication fork arrest at some Ter sites raised questions about their significance. In this study, we examined the genome-wide distribution of Tus and found that only the six innermost Ter sites ( TerA-E and G ) were significantly bound by Tus. We also found that a single ectopic insertion of TerB in its non-permissive orientation could not be achieved, advocating against a need for ‘back-up’ Ter sites. Finally, examination of the genomes of a variety of Enterobacterales revealed a new replication fork trap architecture exclusively found outside the Enterobacteriaceae family. Taken together, our data enabled the delineation of a narrow prototypical Tus-dependent DNA replication fork trap consisting of only two Ter sites.
Publisher: Mary Ann Liebert Inc
Date: 2013
Abstract: Wild animals and the tick species that feed on them form the natural transmission cycle and reservoir of Coxiella burnetii. The objective of this study was to determine whether C. burnetii was present in the blood of host animals and their ticks in northern Queensland, Australia. Three genomic targets were detected using real-time PCR assays-the Coxiella-specific outer membrane protein coding gene (Com1), the multicopy insertion element (IS1111), and the isocitrate dehydrogenase gene (Icd). Quantification of the single-copy targets identified a range of 1.48×10(1) to 4.10×10(3) C. burnetii genome equivalents per microliter in the ticks tested. The detection of Coxiella based on the presence of the genomic targets indicated the occurrence of C. burnetii in both the ticks and whole blood of a variety of native Australian marsupials and confirms these animals are capable of acting as reservoirs of Q fever in northern Queensland.
Publisher: MDPI AG
Date: 29-11-2021
DOI: 10.20944/PREPRINTS202111.0539.V1
Abstract: In Escherichia coli, DNA replication termination is orchestrated by two clusters of Ter sites forming a DNA replication fork trap when bound by Tus proteins. The formation of a & lsquo locked& rsquo Tus-Ter complex is essential for halting incoming DNA replication forks. However, the absence of replication fork arrest at some Ter sites raised questions about their significance. In this study, we examined the genome-wide distribution of Tus and found that only the six innermost Ter sites (TerA-E and G) were significantly bound by Tus. We also found that a single ectopic insertion of TerB in its non-permissive orientation could not be achieved, advocating against a need for & lsquo back-up& rsquo Ter sites. Finally, examination of the genomes of a variety of Enterobacterales revealed a new replication fork trap architecture mostly found outside the Enterobacteriaceae family. Taken together, our data enabled the delineation of a narrow ancestral Tus-dependent DNA replication fork trap consisting of only two Ter sites.
Location: Australia
No related grants have been discovered for Alanna Sorenson.