ORCID Profile
0000-0002-2757-7585
Current Organisation
Murdoch University
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Infectious Agents | Microbiology |
Publisher: Cambridge University Press (CUP)
Date: 06-11-2017
DOI: 10.1017/S0950268817002400
Abstract: We conducted a hospital-based cross-sectional study among children aged years in Thi-Qar Governorate, south-eastern Iraq, in order to examine the prevalence, risk factors and antimicrobial resistance associated with gastroenteritis caused by Salmonella infection. From 320 diarrhoea cases enrolled between March and August 2016, 33 (10·3%, 95% confidence interval (CI) 8·4–12·4) cases were stool culture-positive for non-typhoidal Salmonella enterica . The most commonly identified serovar was Typhimurium (54%). Multivariable logistic regression analysis indicated that the odds of Salmonella infection in children from households supplied by pipe water was 4·7 (95% CI 1·6–13·9) times higher compared with those supplied with reverse osmosis treated water. Similarly, children from households with domestic animals were found to have a higher odds (OR 10·5 95% CI 3·8–28·4) of being Salmonella stool culture-positive. The likelihood of Salmonella infection was higher (OR 3·9 95% CI 1·0–6·4) among children belonging to caregiver with primary vs . tertiary education levels. Lower odds (OR 0·4 95% CI 0·1–0·9) of Salmonella infection were associated with children exclusively breast fed as compared with those exclusively bottle fed. Salmonella infection was three times lower (95% CI 0·1–0·7) in children belonging to caregiver who reported always washing hands after cleaning children following defecation, vs. those belonging to caregivers who did not wash hands. The antimicrobial resistance profile by disc diffusion revealed that non-susceptibility to tetracycline (78·8%), azithromycin (66·7%) and ciprofloxacin (57·6%) were the most commonly seen, and 84·9% of Salmonella isolates were classified as multi-drug resistant. This is the first study on prevalence and antimicrobial resistance of Salmonella infection among children in this setting. This work provides specific epidemiological data which are crucial to understand and combat paediatric diarrhoea in Iraq.
Publisher: Springer Science and Business Media LLC
Date: 02-07-2019
Publisher: American Society for Microbiology
Date: 02-08-2018
DOI: 10.1128/MRA.00869-18
Abstract: Staphylococcus aureus is a serious pathogen of humans and animals. Multilocus sequence type 612 is dominant and highly virulent in South African hospitals but relatively uncommon elsewhere.
Publisher: Hindawi Limited
Date: 15-02-2023
DOI: 10.1155/2023/9682657
Abstract: A study to assess the seroprevalence antibodies against JEV in pigs in Denpasar, Badung, and Karangasem as the representatives of urban, periurban, and rural areas in the province of Bali was conducted. S led pigs’ blood was collected and their sera were tested for antibody detection using commercial IgG ELISA. A standard questionnaire was used to interview the pig owners or farmers to identify the determinants associated with the seropositivity of the antibodies. Overall, 96.6% (95% CI: 94.5–98.1) of 443 pig sera in in idual animal-level seroprevalence were seropositive to the ELISA. Karangasem had the highest test prevalence at 97.3% (95% CI: 93.1–99.2) while Badung had a slightly lower prevalence at 96.6% (95% CI: 92.2–98.9), and Denpasar had the lowest prevalence at 96% (95% CI: 91.5–98.5) ( p = 0.84 ). In herd-level seroprevalence, all s led herds contained one or more seropositive pigs (overall herd-level seroprevalence 100% [95% CI: 97.7–100]). No animal-level factors were significantly associated with seropositivity (all p values .05). For the herd-level risk factors relating to pig management and husbandry practices adopted, no analysis model could be generated, as all the s led herds were seropositive. More than 90% seroprevalence detected in this study indicates high natural JEV infection occurred in pigs, which highlights the high public health risk of the infection in the areas.
Publisher: Elsevier BV
Date: 12-2015
Publisher: Frontiers Media SA
Date: 06-06-2019
Publisher: Elsevier BV
Date: 07-2017
Publisher: Informa UK Limited
Date: 2021
Publisher: Frontiers Media SA
Date: 09-07-2018
Publisher: MDPI AG
Date: 04-06-2019
Abstract: This article describes the formation of the International Pharmacists-as-Immunizers Partnership (IPIP), an international network of pharmacy practice researchers with an interest in pharmacist-administered immunizations. Using funds obtained from a university-sponsored grant, a two-day meeting was held at the University of Waterloo in Canada to discuss published and in-progress research on the topic, identify gaps and priorities for future research, and share implementation strategies used in different jurisdictions. Twelve researchers from five countries attended this initial meeting, identified from both personal networks and from authorship lists from published research. Small- and large-group discussions addressed a number of themes, including: clinical, economic and educational outcomes of the service the perspectives of pharmacists, patients, and other health professionals operational and policy factors influencing uptake safety and the immunizing pharmacist’s role in disaster preparedness. Feedback on our first meeting and outcomes achieved were evaluated on the basis of participant feedback. Key components of the meeting that were considered successful and important lessons learned are summarized, so that other like-minded researchers with a shared pharmacy practice research interest could consider leveraging funding opportunities to establish other international pharmacy practice research networks.
Publisher: Public Library of Science (PLoS)
Date: 23-10-2019
Publisher: Frontiers Media SA
Date: 28-11-2018
Publisher: Portland Press Ltd.
Date: 28-02-2017
DOI: 10.1042/EBC20160055
Abstract: Gram-negative bacteria are known to cause severe infections in both humans and animals. Antimicrobial resistance (AMR) in Gram-negative bacteria is a major challenge in the treatment of clinical infections globally due to the propensity of these organisms to rapidly develop resistance against antimicrobials in use. In addition, Gram-negative bacteria possess highly efficient mechanisms through which the AMR can be disseminated between pathogenic and commensal bacteria of the same or different species. These unique traits of Gram-negative bacteria have resulted in evolution of Gram-negative bacterial strains demonstrating resistance to multiple classes of antimicrobials. The evergrowing resistance issue has not only resulted in limitation of treatment options but also led to increased treatment costs and mortality rates in humans and animals. With few or no new antimicrobials in production to combat severe life-threatening infections, AMR has been described as the one of the most severe, long-term threats to human health. Aside from overuse and misuse of antimicrobials in humans, another factor that has exacerbated the emergence of AMR in Gram-negative bacteria is the veterinary use of antimicrobials that belong to the same classes considered to be critically important for treating serious life-threatening infections in humans. Despite the fact that development of AMR dates back to before the introduction of antimicrobials, the recent surge in the resistance towards all available critically important antimicrobials has emerged as a major public health issue. This review thus focuses on discussing the development, transmission and public health impact of AMR in Gram-negative bacteria in animals.
Publisher: Hindawi Limited
Date: 2014
DOI: 10.1155/2014/238762
Abstract: In this preliminary study we investigate for the first time the biomedical potential of using porous anodic aluminium oxide (AAO) membranes as a cell substrate for culturing the Cercopithecus aethiops (African green monkey) Kidney (Vero) epithelial cell line. One advantage of using the inorganic AAO membrane is the presence of nanometre scale pore channels that allow the exchange of molecules and nutrients across the membrane. The size of the pore channels can be preselected by adjusting the controlling parameters of a temperature controlled two-step anodization process. The cellular interaction and response of the Vero cell line with an in-house synthesised AAO membrane, a commercially available membrane, and a glass control were assessed by investigating cell adhesion, morphology, and proliferation over a 72 h period. The number of viable cells proliferating over the respective membrane surfaces revealed that the locally produced in-house AAO membrane had cells numbers similar to the glass control. The study revealed evidence of focal adhesion sites over the surface of the nanoporous membranes and the penetration of cellular extensions into the pore structure as well. The outcome of the study has revealed that nanometre scale porous AAO membranes have the potential to become practical cell culture scaffold substrates with the capability to enhance adhesion and proliferation of Vero cells.
Publisher: Elsevier BV
Date: 04-2017
Publisher: Microbiology Society
Date: 04-04-2023
DOI: 10.1099/JGV.0.001832
Abstract: Despite recent advances in molecular techniques, infection studies remain an important tool for biosecurity, veterinary and conservation medicines. Experimental infection studies are performed for many reasons: to investigate causal links between pathogens and disease, to study host species susceptibility, to study immune response to inoculation, to investigate pathogen transmission and to investigate methods for infection control. Experimental infection studies using viruses in reptiles have been conducted sporadically since at least the 1930s and this continues to be a fertile area of research. This review catalogues previously published research in the field. The key parameters of each study are tabulated, providing a summary of more than 100 experiments linked to their original publications. Common themes and trends within the data are discussed.
Publisher: American Association of Avian Pathologists (AAAP)
Date: 09-2013
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/AN17358
Abstract: Antimicrobial use and antimicrobial resistance (AMR) in intensive pig production and its potential impacts to human and animal health are very much under the spotlight, both internationally, and within Australia. While the majority of AMR of medical importance is associated with the exclusive use of antimicrobials in humans, resistance in zoonotic foodborne pathogens such as Salmonella and C ylobacter, and livestock commensal bacteria such as Escherichia coli and Enterococcus spp., is under increased scrutiny. This is primarily due to the current reliance on many of the same drug classes as used in human medicine for treatment and control of bacterial diseases of livestock. Furthermore, the development of multidrug resistance in pathogens such as enterotoxigenic E. coli may drive off-label use of critically important drug classes such as 3rd-generation cephalosporins. This could lead to the emergence and lification of resistance genes of potential public health significance in both pathogens and commensal bacteria. Livestock-associated and community-associated methicillin-resistant Staphylococcus aureus has also recently been detected in Australian pigs as a result of human-to-animal transmission and are a potential public health issue for in-contact piggery workers. Australia is in a unique position compared with many of its international trading partners due to its isolation, ban on importation of livestock and conservative approach to antimicrobial registration, including reservation of the fluoroquinolone class for use in humans and companion animals only. Cross-sectional AMR surveys of pathogens and commensals in healthy pigs have identified only low frequency of resistance to critically important drug classes. Nevertheless, resistance to critically important antimicrobials has emerged and careful antimicrobial stewardship is required to ensure that these low levels do not increase. In this report, we review AMR of significance to the Australian pig industry and identify potential prevention and control measures.
Publisher: Medip Academy
Date: 2015
Publisher: MDPI AG
Date: 11-03-2019
DOI: 10.3390/TROPICALMED4010046
Abstract: Australian bat lyssavirus (ABLV) is a known causative agent of neurological disease in bats, humans and horses. It has been isolated from four species of pteropid bats and a single microbat species (Saccolaimus flaviventris). To date, ABLV surveillance has primarily been passive, with active surveillance concentrating on eastern and northern Australian bat populations. As a result, there is scant regional ABLV information for large areas of the country. To better inform the local public health risks associated with human-bat interactions, this study describes the lyssavirus prevalence in microbat communities in the South West Botanical Province of Western Australia. We used targeted real-time PCR assays to detect viral RNA shedding in 839 oral swabs representing 12 species of microbats, which were s led over two consecutive summers spanning 2016–2018. Additionally, we tested 649 serum s les via Luminex® assay for reactivity to lyssavirus antigens. Active lyssavirus infection was not detected in any of the s les. Lyssavirus antibodies were detected in 19 in iduals across six species, with a crude prevalence of 2.9% (95% CI: 1.8–4.5%) over the two years. In addition, we present the first records of lyssavirus exposure in two Nyctophilus species, and Falsistrellus mackenziei.
Publisher: Wiley
Date: 29-09-2022
Abstract: From four focused compound libraries based on the known anticoccidial agent robenidine, 44 compounds total were synthesised and screened for antigiardial activity. All active compounds were counter‐screened for antibiotic and cytotoxic action. Of the analogues examined, 21 displayed IC 50 μM, seven with IC 50 .0 μM. Most active were 2,2′‐ bis {[4‐(trifluoromethoxy)phenyl]methylene}carbonimidic dihydrazide hydrochloride ( 30 ), 2,2′‐ bis {[4‐(trifluoromethylsulfanyl)phenyl]methylene}carbonimidic dihydrazide hydrochloride ( 32 ), and 2,2′‐bis[(2‐bromo‐4,5‐dimethoxyphenyl)methylene]carbonimidic dihydrazide hydrochloride ( 41 ) with IC 50 =0.2 μM. The maximal observed activity was a 5 h IC 50 value of 0.2 μM for 41 . The clinically used metronidazole was inactive at this timepoint at a concentration of 25 μM. Robenidine off‐target effects at bacteria and cell line toxicity were removed. Analogue 41 was well tolerated in mice treated orally (100 mg/kg). Following 5 h treatment with 41 , no Giardia regrowth was noted after 48 h.
Publisher: Frontiers Media SA
Date: 23-05-2018
Publisher: Springer Science and Business Media LLC
Date: 14-01-2020
DOI: 10.1186/S12891-020-3052-8
Abstract: There is some limited evidence for the presence of viruses in herniated disc material including a previous case series that claimed to provide “unequivocal evidence of the presence of herpes virus DNA in intervertebral disc specimens of patients with lumbar disc herniation suggesting the potential role of herpes viruses as a contributing factor to the pathogenesis of degenerative disc disease”. This study has not been replicated. The objective of our study was to determine if viruses were present in herniated disc fragments in participants with a prior history of back pain. We recruited fifteen participants with a history of prior low-back pain prior to undergoing disc herniation surgery in the lumbar spine. Harvested disc s les were subject to next generation sequencing for detection of both RNA and DNA viral pathogens. Additionally, s les were analysed by a broadly reactive PCR targeting herpesviral DNA. Ethics approval was granted by the Human Research Ethics Committees of both Murdoch University, and St John of God Hospital, Western Australia. Of the fifteen research participants, 8 were female. Mean age was 49.4 years (SD 14.5 yrs) with a range of 24–70 years. All participants had prior back pain with mean time since first ever attack being 8.8 years (SD 8.8 yrs). No s les contained significant DNA sequences relating to known human viral agents. Inconsequential retroviral sequences were commonly found and were a mixture of putative animal and human retroviral protein coding segments. All s les were negative for herpesvirus DNA when analysed by pan-herpesvirus PCR. This study found no viral pathogens in any intervertebral disc fragments of patients who had previous back pain and underwent discectomy for disc herniation and thus it is unlikely that viruses are associated with disc herniation, however given the contradiction between key studies enhanced replication of this experiment is recommended.
Publisher: Springer Science and Business Media LLC
Date: 17-07-2019
Publisher: Oxford University Press (OUP)
Date: 23-09-2019
DOI: 10.1093/JAS/SKZ303
Abstract: An infection model with enterotoxigenic Escherichia coli (ETEC) harboring the F4 fimbriae can be used to assess the impacts that various challenges associated with weaning (e.g., dietary, psychological, environmental) have on the expression of postweaning diarrhea. The objective of this study was to develop a novel inoculation method for administering an ETEC culture that would induce a higher proportion of ETEC-F4 diarrhea, in pigs that genetically showed ETEC-F4 susceptibility or resistance. The study was designed as a factorial arrangement of treatments with the factors being 1) partially susceptible or resistant to ETEC-F4 based on genetic testing, and 2) 4 challenge treatments, being a) a conventional liquid broth method using a drenching gun [Positive control (PC)], b) a Syringe method, c) a Capsule method, and d) Negative control [pigs not challenged (NC)]. At 21 ± 3 d of age (mean ± SEM), 48 male castrate pigs (Large White × Landrace) weighing approximately 7.0 ± 1.18 kg were allocated to 4 treatment groups in 2 replicate pens (6 pigs per pen). Initial ETEC-F4 susceptibility was based on a DNA marker test and each treatment group had 9 partially susceptible and 3 resistant pigs. On days 7 and 8 after weaning, pigs were challenged with ETEC (serotype O149:K88 toxins LT1, ST1, ST2, and EAST). On each inoculation day the PC pigs were orally dosed with 9 mL 7.12 × 109 colony-forming unit (CFU), the Syringe pigs with 0.8 mL 6.72 × 109 CFU, the Capsule pigs were orally administered 2 capsules containing 0.8 mL 3.28 × 109 CFU, and the NC pigs 1 mL of phosphate-buffered saline (PBS) solution. Approximately 72 h after infection, 44, 22, 78, and 0% of partially susceptible pigs in the PC, the Syringe, the Capsule, and the NC group had developed ETEC-F4 diarrhea (P = 0.007). Partially susceptible pigs had a higher diarrhea index (DI) compared to resistant pigs (31.5 vs. 4.8, P 0.001). The NC group had a lower DI compared to the PC and Capsule pigs (3.9, 38.1, and 40.3, respectively, P 0.005). Following infection, genetically resistant pigs in the Capsule group had a DI of zero and the partially susceptible pigs had a DI of 55.6 (P = 0.014). This study showed that genetically screening pigs and using a Capsule to deliver ETEC-F4 can increase cases of diarrhea and the efficiency of the challenge model. Taken together, these methods have the potential to reduce the number of pigs needed in future experimental infection studies.
Publisher: Elsevier BV
Date: 02-2018
DOI: 10.1016/J.MIMET.2017.11.025
Abstract: This study describes a neonatal mouse model of Giardia infection for development of novel antigiardials. Mice were infected with the axenically cultured Assemblage A BAH2c2 strain, with 10
Publisher: Springer Science and Business Media LLC
Date: 29-01-2010
DOI: 10.1007/S00705-010-0588-1
Abstract: Influenza A virus, A/Eurasian coot/Western Australia/2727/79 (H6N2), from an apparently healthy coot was characterized. This virus was able to grow on MDCK cells and produce a cytopathic effect in the absence of exogenous trypsin and was further characterized as a low-pathogenicity avian influenza virus, with an intravenous pathogenicity index of 0.15 and a (321)PQAETRG(328) motif at the cleavage site of the haemagglutinin gene. It infected domestic chickens, resulting in seroconversion and intermittent virus excretion via cloaca and oropharynx under experimental conditions. Phylogenetic analysis showed that the viral genes were closely related to other waterfowl isolates from the same geographic area and time period.
Publisher: Public Library of Science (PLoS)
Date: 25-01-2019
Publisher: SAGE Publications
Date: 18-12-2015
Abstract: The prevalence of organisms known to be associated with bovine respiratory disease (BRD) was investigated in cattle prior to export. A quantitative reverse transcription polymerase chain reaction assay was used to detect nucleic acids from the following viruses and bacteria in nasal swab s les: Bovine coronavirus (BoCV Betacoronavirus 1), Bovine herpesvirus 1 (BoHV-1), Bovine viral diarrhea virus 1 (BVDV-1), Bovine respiratory syncytial virus (BRSV), Bovine parainfluenza virus 3 (BPIV-3), Histophilus somni, Mycoplasma bovis, Mannheimia haemolytica, and Pasteurella multocida. Between 2010 and 2012, nasal swabs were collected from 1,484 apparently healthy cattle destined for export to the Middle East and Russian Federation. In addition, whole blood s les from 334 animals were tested for antibodies to BoHV-1, BRSV, BVDV-1, and BPIV-3 using enzyme-linked immunosorbent assay. The nasal prevalence of BoCV at the in idual animal level was 40.1%. The nasal and seroprevalence of BoHV-1, BRSV, BVDV-1, and BPIV-3 was 1.0% and 39%, 1.2% and 46%, 3.0% and 56%, and 1.4% and 87%, respectively. The nasal prevalence of H. somni, M. bovis, M. haemolytica, and P. multocida was 42%, 4.8%, 13.4%, and 26%, respectively. Significant differences in nasal and seroprevalence were detected between groups of animals from different geographical locations. The results of the current study provide baseline data on the prevalence of organisms associated with BRD in Australian live export cattle in the preassembly period. This data could be used to develop strategies for BRD prevention and control prior to loading.
Publisher: MDPI AG
Date: 14-05-2020
Abstract: Streptococcus suis is a swine pathogen and a zoonotic agent afflicting people in close contact with infected pigs or pork meat. Sporadic cases of human infections have been reported worldwide. In addition, S. suis outbreaks emerged in Asia, making this bacterium a primary health concern in this part of the globe. In pigs, S. suis disease results in decreased performance and increased mortality, which have a significant economic impact on swine production worldwide. Facing the new regulations in preventive use of antimicrobials in livestock and lack of effective vaccines, control of S. suis infections is worrisome. Increasing and sharing of knowledge on this pathogen is of utmost importance. As such, the pathogenesis and epidemiology of the infection, antimicrobial resistance, progress on diagnosis, prevention, and control were among the topics discussed during the 4th International Workshop on Streptococcus suis (held in Montreal, Canada, June 2019). This review gathers together recent findings on this important pathogen from lectures performed by lead researchers from several countries including Australia, Canada, France, Germany, Japan, Spain, Thailand, The Netherlands, UK, and USA. Finally, policies and recommendations for the manufacture, quality control, and use of inactivated autogenous vaccines are addressed to advance this important field in veterinary medicine.
Publisher: Springer Science and Business Media LLC
Date: 21-10-2016
DOI: 10.1038/SREP35527
Abstract: Carbapenem-resistant Enterobacteriaceae (CRE) are a pressing public health issue due to limited therapeutic options to treat such infections. CREs have been predominantly isolated from humans and environmental s les and they are rarely reported among companion animals. In this study we report on the isolation and plasmid characterization of carbapenemase (IMP-4) producing Salmonella enterica Typhimurium from a companion animal. Carbapenemase-producing S. enterica Typhimurium carrying bla IMP-4 was identified from a systemically unwell (index) cat and three additional cats at an animal shelter. All isolates were identical and belonged to ST19. Genome sequencing revealed the acquisition of a multidrug-resistant IncHI2 plasmid (pIMP4-SEM1) that encoded resistance to nine antimicrobial classes including carbapenems and carried the bla IMP-4 - qacG - aacA4 - catB3 cassette array. The plasmid also encoded resistance to arsenic (MIC-150 mM). Comparative analysis revealed that the plasmid pIMP4-SEM1 showed greatest similarity to two bla IMP-8 carrying IncHI2 plasmids from Enterobacter spp. isolated from humans in China. This is the first report of CRE carrying a bla IMP-4 gene causing a clinical infection in a companion animal, with presumed nosocomial spread. This study illustrates the broader community risk entailed in escalating CRE transmission within a zoonotic species such as Salmonella , and in a cycle that encompasses humans, animals and the environment.
Publisher: Wiley
Date: 21-03-2011
DOI: 10.1111/J.1751-0813.2010.00680.X
Abstract: To report the occurrence and pathology of porcine circovirus type 2 (PCV2)-associated disease (PCVAD) of postweaning pigs in two Australian pig herds. Mortality data from two commercial piggeries that experienced higher than normal postweaning illthrift and mortalities were examined. Gross and histopathological examinations were performed on the index cases, and at weekly intervals thereafter for a period of 10 weeks. Specimens were submitted to the laboratory for routine diagnostic testing and for exclusion of porcine reproductive and respiratory syndrome virus (PRRSV). The genomes of two strains of PCV2 isolated during testing were sequenced. Mortality rates in weaned, 5-12-week-old pigs spiked significantly during mid to late 2007. This increase in the mortalities was mainly attributed to salmonella-associated diarrhoea and illthrift. Salmonellosis was diagnosed in 73/110 cases inclusive of both piggeries. Many pigs also had chronic granulomatous lymphadenitis and diffuse histiocytic interstitial pneumonia consistent with PCVAD and associated with varying amounts of PCV2 antigen and inclusion bodies. All s les tested for PRRSV were negative. Sequence analysis of the PCV2 isolates showed strain differences between piggeries. This report describes the first outbreaks of PCVAD in growing pigs in Western Australia (WA) and describes lesions not previously seen in this laboratory. It also describes the first isolation of a PCV2 group 1 virus in WA associated with PCVAD. Although the outbreaks of PCVAD occurred with concurrent salmonellosis, the two diseases were unrelated. Neither of the outbreaks met the Australian case definition for the diagnosis of postweaning multisystemic wasting syndrome.
Publisher: Wiley
Date: 26-10-2015
DOI: 10.1111/AVJ.12379
Abstract: Avian influenza viruses (AIVs) are found worldwide in numerous bird species, causing significant disease in gallinaceous poultry and occasionally other species. Surveillance of wild bird reservoirs provides an opportunity to add to the understanding of the epidemiology of AIVs. This study examined key findings from the National Avian Influenza Wild Bird Surveillance Program over a 5-year period (July 2007-June 2012), the main source of information on AIVs circulating in Australia. The overall proportion of birds that tested positive for influenza A via PCR was 1.9 ± 0.1%, with evidence of widespread exposure of Australian wild birds to most low pathogenic avian influenza (LPAI) subtypes (H1-13, H16). LPAI H5 subtypes were found to be dominant and widespread during this 5-year period. Given Australia's isolation, both geographically and ecologically, it is important for Australia not to assume that the epidemiology of AIV from other geographic regions applies here. Despite all previous highly pathogenic avian influenza outbreaks in Australian poultry being attributed to H7 subtypes, widespread detection of H5 subtypes in wild birds may represent an ongoing risk to the Australian poultry industry.
Publisher: Elsevier BV
Date: 11-2018
DOI: 10.1016/J.IJFOODMICRO.2018.07.007
Abstract: Salmonella is a major cause of human foodborne illnesses worldwide however, little is known about its occurrence and genomic characteristics in food sources in many developing countries. This study investigates the occurrence, serotypes distribution, antimicrobial resistance, and multilocus sequence types (ST) of Salmonella isolated from 400 imported frozen chicken carcasses sold in the markets of Thi-Qar, south-eastern Iraq. Salmonella was detected in 46 out of 400 tested s les [11.5% (95% confidence interval: 8.5%-15.0%)]. S. Typhimurium was the most abundant (30.4%) among 14 different serotypes recovered from the tested frozen carcasses. Antimicrobial resistance was most frequently detected against tetracycline (84.4%), nalidixic acid (80.4%), streptomycin (69.6%) and trimethoprim/sulfamethoxazole (65.2%). Whole-genome sequencing (WGS) analysis revealed that 18 isolates harbored four β-lactamase resistance genes, with bla
Publisher: Elsevier BV
Date: 2008
DOI: 10.1016/J.JVIROMET.2007.07.029
Abstract: International trade in pig meat has resulted in some countries placing restrictions on the importation of pig meat, with requirements for cooking of imported meat to destroy viral agents. This study investigated the in vitro resistance of an Australian strain of porcine circovirus type 2 (PCV2), the causative agent of post-weaning multisystemic wasting syndrome (PMWS), to heat treatment. The viability of the virus in cell cultures was determined by a combination of reverse transcriptase polymerase chain reaction (RT-PCR) to detect viral transcripts, and immunohistochemistry (IHC) to visualize viral capsid antigen. PCV2 retained infectivity when heated at 75 degrees C for 15 min but was inactivated by heating at 80 degrees C and above for 15 min. The results provide important information on the thermal tolerance of PCV2, which can be taken into account in risk assessments for trade in pig meat and porcine-derived biological products.
Publisher: SAGE Publications
Date: 11-02-2014
Abstract: The cause of death in 215 cattle on 20 long-haul live export voyages from Australia to the Middle East, Russia, and China was investigated between 2010 and 2012 using gross, histologic, and/or molecular pathology techniques. A quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay was used to detect nucleic acids from viruses and bacteria known to be associated with respiratory disease in cattle: Bovine coronavirus ( Betacoronavirus 1), Bovine herpesvirus 1, Bovine viral diarrhea virus 1 and 2, Bovine respiratory syncytial virus, Bovine parainfluenza virus 3, Histophilus somni, Mycoplasma bovis, Mannheimia haemolytica, and Pasteurella multocida. The most commonly diagnosed cause of death was respiratory disease (107/180, 59.4%), followed by lameness ( n = 22, 12.2%), ketosis ( n = 12, 6.7%), septicemia ( n = 11, 6.1%), and enteric disease ( n = 10, 5.6%). Two thirds (130/195) of animals from which lung s les were collected had histologic changes and/or positive qRT-PCR results indicative of infectious lung disease: 93 out of 130 (72%) had evidence of bacterial infection, 4 (3%) had viral infection, and 29 (22%) had mixed bacterial and viral infections, and for 4 (3%) the causative organism could not be identified. Bovine coronavirus was detected in up to 13% of cattle tested, and this finding is likely to have important implications for the management and treatment of respiratory disease in live export cattle. Results from the current study indicate that although overall mortality during live export voyages is low, further research into risk factors for developing respiratory disease is required.
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.VETMIC.2018.04.004
Abstract: Methicillin-resistant coagulase-negative staphylococci (MRCoNS) have recently emerged as a significant cause of bovine mastitis worldwide. Here we describe the isolation of MRCoNS from cases of bovine mastitis from a single dairy farm in Australia. Fourteen CoNS isolates were identified as MRCoNS on the basis of having an oxacillin MIC of ≥0.5 μg/mL. The isolates were speciated as S. chromogenes (n = 1) S. fleurettii (n = 1), S. haemolyticus (n = 2), S. sciuri (n = 5), S. simulans (n = 1) S. succinus (n = 2) and S. xylosus (n = 2). Five of the isolates (S. fleuretti, S. haemolyticus S. sciuri and two S. succinus) were mecA-positive. We also detected a previously described S. sciuri mecA homolog in four oxacillin-resistant S. sciuri isolates. The remainder of the putative MRCoNS did not contain any mecA-related resistance determinants in their genomes. Comparative genomic analysis of three previously published S. sciuri isolates, from humans, a squirrel and a cereal crop (rice), and a representative isolate from our study demonstrated clustering and a high degree of genetic homogeneity (>95%), suggesting S. sciuri has low host specificity. In conclusion, CoNS, in particular S. sciuri, may act as a reservoir for SCCmec elements that can easily be spread between different host species by direct cross-infection.
Publisher: Elsevier BV
Date: 10-2017
DOI: 10.1016/J.VIRUSRES.2017.09.016
Abstract: Poxviruses have previously been detected in macropods with cutaneous papillomatous lesions, however to date, no comprehensive analysis of a poxvirus from kangaroos has been performed. Here we report the genome sequences of a western grey kangaroo poxvirus (WKPV) and an eastern grey kangaroo poxvirus (EKPV), named for the host species from which they were isolated, western grey (Macropus fuliginosus) and eastern grey (Macropus giganteus) kangaroos. Poxvirus DNA from WKPV and EKPV was isolated and entire coding genome regions determined through Roche GS Junior and Illumina Miseq sequencing, respectively. Viral genomes were assembled using MIRA and SPAdes, and annotations performed using tools available from the Viral Bioinformatics Resource Centre. Histopathology and transmission electron microscopy analysis was also performed on WKPV and its associated lesions. The WKPV and EKPV genomes show 96% identity (nucleotide) to each other and phylogenetic analysis places them on a distinct branch between the established Molluscipoxvirus and Avipoxvirus genera. WKPV and EKPV are 170 kbp and 167 kbp long, containing 165 and 162 putative genes, respectively. Together, their genomes encode up to 47 novel unique hypothetical proteins, and possess virulence proteins including a major histocompatibility complex class II inhibitor, a semaphorin-like protein, a serpin, a 3-β-hydroxysteroid dehydrogenase/δ 5→4 isomerase, and a CD200-like protein. These viruses also encode a large putative protein (WKPV-WA-039 and EKPV-SC-038) with a C-terminal domain that is structurally similar to the C-terminal domain of a cullin, suggestive of a role in the control of host ubiquitination. The relationship of these viruses to members of the Molluscipoxvirus and Avipoxvirus genera is discussed in terms of sequence similarity, gene content and nucleotide composition. A novel genus within subfamily Chordopoxvirinae is proposed to accommodate these two poxvirus species from kangaroos we suggest the name, Thylacopoxvirus (thylaco-: [Gr.] thylakos meaning sac or pouch).
Publisher: American Society for Microbiology
Date: 15-08-2018
DOI: 10.1128/JVI.00316-18
Abstract: We describe the evolutionary origins and antigenic properties of influenza A viruses isolated from two separate Australian swine populations from 2012 to 2016, showing that these viruses are distinct from each other and from those isolated from swine globally. Whole-genome sequencing of virus isolates revealed a high genotypic ersity that had been generated exclusively through the introduction and establishment of human influenza viruses that circulated in past seasons. We detected six reassortants with gene segments derived from human H1N1/H1N1pdm09 and various human H3N2 viruses that circulated during various periods since 1968. We also found that these swine viruses were not related to swine viruses collected elsewhere, indicating independent circulation. The detection of unique lineages and genotypes in Australia suggests that isolated swine populations that are sufficiently large can sustain influenza virus for extensive periods we show direct evidence of a sustained transmission for at least 4 years between 2012 and 2016.
Publisher: MDPI AG
Date: 13-12-2019
DOI: 10.3390/V11121157
Abstract: Bats are known reservoirs of a wide variety of viruses that rarely result in overt clinical disease in the bat host. However, anthropogenic influences on the landscape and climate can change species assemblages and interactions, as well as undermine host-resilience. The cumulative result is a disturbance of bat–pathogen dynamics, which facilitate spillover events to sympatric species, and may threaten bat communities already facing synergistic stressors through ecological change. Therefore, characterisation of viral pathogens in bat communities provides important basal information to monitor and predict the emergence of diseases relevant to conservation and public health. This study used targeted molecular techniques, serological assays and next generation sequencing to characterise adenoviruses, coronaviruses and paramyxoviruses from 11 species of insectivorous bats within the South West Botanical Province of Western Australia. Phylogenetic analysis indicated complex ecological interactions including virus–host associations, cross-species infections, and multiple viral strains circulating concurrently within selected bat populations. Additionally, we describe the entire coding sequences for five alphacoronaviruses (representing four putative new species), and one novel adenovirus. Results indicate that viral burden (both prevalence and richness) is not homogeneous among species, with Chalinolobus gouldii identified as a key epidemiological element within the studied communities.
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.VETMIC.2019.05.024
Abstract: This study evaluated the diagnostic test accuracy of disc diffusion relative to broth-microdilution for clinical Staphylococcus pseudintermedius isolated from dogs in Australia (n = 614). Accuracy of disc diffusion and broth-microdilution for oxacillin relative to mecA real-time PCR was also assessed. Each isolate had paired minimum inhibitory concentration and zone diameter values for ten antimicrobial agents. Data was dichotomised using Clinical and Laboratory Standards Institute susceptible and resistant clinical breakpoints. Test accuracy was reported using relative diagnostic sensitivity (RSe), specificity (RSp), likelihood ratio pairs, diagnostic odds ratio, and area-under-the receiver-operating characteristic (ROC AUC) analysis. Disc diffusion was found to have high test accuracy for most antimicrobials (ROC AUC range: 0.96 - 0.99) except rif icin (ROC AUC = 0.80). The RSp of disc diffusion was high for all antimicrobials (range, 97.1%-100%). However, RSe was considerably variable (range, 35.7%-98.8%), particularly for amoxicillin-clavulanic acid (51.5%, 95% CI, 38.9%, 64.0%), cefoxitin (35.7%, 95% CI, 12.8%, 64.9%), and cephalothin (43.6%, 95% CI, 27.8%, 60.4%). When disc diffusion and broth-microdilution were compared to mecA real-time PCR, the overall accuracy of both assays was similar (ROC AUC, 0.99 respectively). However, the RSe for broth-microdilution (96.1%, 95% CI, 88.9%, 99.2%) was significantly higher than for disc diffusion (86.8%, 95% CI, 77.1%, 93.5%) (McNemars mid-p value 0.01). Overall, these findings demonstrate that for most antimicrobials, disc diffusion performed according to CLSI guidelines can be used to differentiate clinical S. pseudintermedius isolates that might otherwise be assessed by broth-microdilution, provided consideration is given to the performance estimates reported here.
Publisher: Public Library of Science (PLoS)
Date: 16-11-2018
Publisher: MDPI AG
Date: 25-06-2019
DOI: 10.3390/TROPICALMED4020096
Abstract: Australia was previously believed to be free of enzootic swine influenza viruses due strict quarantine practices and use of biosecure breeding facilities. The first proven Australian outbreak of swine influenza occurred in Western Australian in 2012, revealing an unrecognized zoonotic risk, and a potential future pandemic threat. A public health investigation was undertaken to determine whether zoonotic infections had occurred and to reduce the risk of further transmission between humans and swine. A program of monitoring, testing, treatment, and vaccination was commenced, and a serosurvey of workers was also undertaken. No acute infections with the swine influenza viruses were detected. Serosurvey results were difficult to interpret due to previous influenza infections and past and current vaccinations. However, several workers had elevated haemagglutination inhibition (HI) antibody levels to the swine influenza viruses that could not be attributed to vaccination or infection with contemporaneous seasonal influenza A viruses. However, we lacked a suitable control population, so this was inconclusive. The experience was valuable in developing better protocols for managing outbreaks at the human–animal interface. Strict adherence to biosecurity practices, and ongoing monitoring of swine and their human contacts is important to mitigate pandemic risk. Strain specific serological assays would greatly assist in identifying zoonotic transmission.
Publisher: Wiley
Date: 27-05-2020
DOI: 10.1111/ZPH.12721
Publisher: Wiley
Date: 11-05-2016
DOI: 10.1111/AVJ.12447
Abstract: A captive breeding colony of 9 greater bilbies (Macrotis lagotis) exhibited mild upper respiratory signs and sudden deaths with 100% mortality over a 2-week period. Histologically, acute necrotising and erosive epithelial lesions throughout the upper respiratory system and bronchi were associated with eosinophilic intranuclear inclusion bodies. Inclusions were also present in hepatocytes and adrenocortical cells, but were not always associated with necrosis. Transmission electron microscopy of lung sections revealed nucleocapsids forming arrays within some nuclei. A pan-herpesvirus PCR yielded a 440-bp product, with sequencing confirming homology with the alphaherpesviruses. Viral culture in a marsupial cell line resulted in cytopathic effect consistent with an alphaherpesvirus. This is the first report of a herpesvirus-associated disease in greater bilbies.
Publisher: Elsevier BV
Date: 06-2020
Publisher: CSIRO Publishing
Date: 2013
DOI: 10.1071/ZO13077
Abstract: The woylie (Bettongia penicillata ogilbyi) is a critically endangered small Australian marsupial that is in a state of accelerated population decline for reasons that are currently unknown. The aim of the present study was to elucidate the involvement of several viral pathogens through strategic serological testing of several wild woylie populations. Testing for antibodies against the Wallal and Warrego serogroup of orbiviruses, Macropod herpesvirus 1 and Encephalomyocarditis virus in woylie sera was undertaken through virus neutralisation tests. Moreover, testing for antibodies against the the alphaviruses Ross River virus and Barmah Forest virus and the flaviviruses Kunjin virus and Murray Valley encephalitis virus was undertaken through virus neutralisation tests and ELISA mainly because of the interest in the epidemiology of these important zoonoses as it was considered unlikely to be the cause of the decline. Between 15 and 86 s les were tested for each of the four sites in south-western Australia (Balban, Keninup, Warrup and Karakamia). Results indicated no exposure to any of the viral pathogens investigated, indicating that all populations are currently naïve and may be at risk if these pathogens were to be introduced.
Publisher: Springer Science and Business Media LLC
Date: 12-08-2019
Publisher: Microbiology Society
Date: 09-2016
DOI: 10.1099/JGV.0.000538
Abstract: The carcass of an Australian little red flying fox (Pteropus scapulatus) which died following entrapment on a fence was submitted to the laboratory for Australian bat lyssavirus exclusion testing, which was negative. During post-mortem, multiple nodules were noted on the wing membranes, and therefore degenerate PCR primers targeting the poxvirus DNA polymerase gene were used to screen for poxviruses. The poxvirus PCR screen was positive and sequencing of the PCR product demonstrated very low, but significant, similarity with the DNA polymerase gene from members of the Poxviridae family. Next-generation sequencing of DNA extracted from the lesions returned a contig of 132 353 nucleotides (nt), which was further extended to produce a near full-length viral genome of 133 492 nt. Analysis of the genome revealed it to be AT-rich with inverted terminal repeats of at least 1314 nt and to contain 143 predicted genes. The genome contains a surprisingly large number (29) of genes not found in other poxviruses, one of which appears to be a homologue of the mammalian TNF-related apoptosis-inducing ligand (TRAIL) gene. Phylogenetic analysis indicates that the poxvirus described here is not closely related to any other poxvirus isolated from bats or other species, and that it likely should be placed in a new genus.
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.IJANTIMICAG.2019.08.022
Abstract: Staphylococcus aureus is a serious human and animal pathogen. Multilocus sequence type 612 (ST612) is the dominant methicillin-resistant S. aureus (MRSA) clone in certain South African hospitals and is sporadically isolated from horses and horse-associated veterinarians in Australia. Colonisation and infection by ST612-MRSA is increasing in Western Australia. Whole-genome sequencing was performed for 51 isolates of ST612-MRSA from Western Australian patients and healthcare workers, South African hospital patients, Australian veterinarians and New South Wales horses. Core genome phylogenies suggested that Australian equine and veterinarian-associated ST612-MRSA were monophyletic. In idual Western Australian isolates grouped either with this equine-associated lineage or more erse lineages related to those in South African hospitals. Bioinformatic analyses of the complete ST612-MRSA reference genome SVH7513 confirmed that ST612-MRSA was closely related to ST8 USA500 MRSA. Common use of rif icin in South Africa and equine veterinarian practice may favour ST612-MRSA in these settings. Humans and horses colonised with ST612-MRSA are potential reservoirs for MRSA in Australia.
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.
Publisher: Public Library of Science (PLoS)
Date: 09-11-2016
Publisher: Elsevier BV
Date: 11-2019
DOI: 10.1016/J.IJFOODMICRO.2019.108305
Abstract: In recent years, the number of human salmonellosis cases in Western Australia (WA) has increased more dramatically than in any other Australian state. In 2017, the number of cases in WA was more than double the five-year average, and eggs had emerged as the key culprit for several Salmonella foodborne disease outbreaks. To better understand such an epidemiologically intriguing situation, our research goal was to investigate the prevalence, serovar ersity, multilocus sequence types, and antimicrobial resistance of non-typhoidal Salmonella contamination in retail eggs produced and sold in WA. A total of 200 visually clean and intact retail egg s les (each containing a dozen eggs) were purchased for one year (2017-2018) from supermarkets in metropolitan Perth, the capital of WA. For each s le, the contents and shells of the 12 eggs were separately pooled and cultured according to standard methods. Overall, Salmonella was detected in 11.5% (23/200) of the tested egg s les. Salmonella was isolated from 4.5% (9/200) and 3% (6/200) of eggshells and egg contents, respectively. In 4% (8/200) of the s les, Salmonella was recovered from both eggshell and egg contents. Isolates from positive retail egg s les were serotyped as either S. Typhimurium (52.2% [12/23]) or S. Infantis (39.1% [9/23]). Both serotypes were concurrently recovered from two different retail egg s les. We retained a set of both S. Typhimurium (n = 29) and S. Infantis (n = 12) isolates from all Salmonella-positive retail packs (n = 23) for further characterization. Only two (S. Typhimurium) isolates showed resistance to icillin, of which one carried β-lactamase resistance gene bla
Start Date: 12-2018
End Date: 12-2023
Amount: $355,000.00
Funder: Australian Research Council
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