ORCID Profile
0000-0002-9505-5498
Current Organisations
University of Adelaide
,
South Australian Health and Medical Research Institute Limited
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Publisher: Elsevier BV
Date: 05-2021
DOI: 10.1016/J.JCF.2020.11.009
Abstract: The emergence of multidrug resistant (MDR) pathogens represents a profound threat to global health. In iduals with CF have amongst the highest cumulative antibiotic exposure of any patient group, including to critically-important last-line agents. While there is little evidence that antibiotic resistance in airway pathogens results in worse clinical outcomes for CF patients, the potential emergence of MDR pathogens in non-respiratory systems, as a consequence of CF care, represents a potential health threat to the wider population, including family and carers. Stool from 19 adults with CF and 16 healthy adult controls was subjected to metagenomic sequencing, to assess faecal resistome, and culture-based analysis. Resistant isolates were identified phenotypically, and genetic determinants of resistance characterised by whole genome sequencing. CF and control faecal resistomes differed significantly (P = 0.0003). The proportion of reads that mapped to mobile genetic elements was significantly higher in CF (P = 0.014) and the composition was significantly different (P = 0.0001). Notably, CF patients displayed higher carriage of plasmid-mediated aminoglycoside-modifying genes ant(6)-Ib, aac(6')-Ip, and aph(3')-IIIa (P < 0.01). Culture-based analysis supported higher aminoglycoside resistance, with a higher proportion of aminoglycoside-resistant, Gram-negative bacteria (P < 0.0001). Isolated extended spectrum beta lactamase (ESBL)-positive Escherichia coli from CF stool exhibited phenotypic resistance to tobramycin and gentamicin. Genomic analysis showed co-localisation of both aminoglycoside resistance and ESBL genes, consistent with MDR emergence through horizontal gene transfer. The carriage of potentially transmissible resistance within the adult CF gut microbiome is considerably greater than in healthy in iduals and could contribute to the emergence and dissemination of MDR pathogens.
Publisher: MDPI AG
Date: 29-11-2019
Abstract: Chicken meat can potentially become contaminated with bacteria at the processing plant. In Australia, there is currently a lack of knowledge on the parameters and indications of use of non-chlorine based treatments in the chicken meat processing plants. Chlorine is widely used as a sanitizer in Australian chicken meat processing plants but due to occupational health and safety concerns and consumer perception, there is a need to identify alternative sanitizers. This study aimed to assess the efficacy of four different sanitizers in reducing the microbial load from naturally contaminated chicken meat carcasses collected from the processing plants in South Australia. There was a significant variation in a load of C ylobacter and total viable count (TVC) between s les collected from two different processing plants and within carcass batches collected from the same plant that was tested during the study. All sanitizers generally reduced the load of C ylobacter on chicken meat carcasses. Treatment with acidified sodium chlorite significantly reduced the level of Salmonella enterica serovars at all temperatures tested during this study. These findings are helpful to the industry for selection of the appropriate sanitizers. Findings are also useful for the regulatory authorities in Australia for providing approval for the use of sanitizers.
Publisher: Springer Science and Business Media LLC
Date: 22-05-2021
DOI: 10.1186/S12885-021-08296-4
Abstract: The gut microbiota influences many aspects of host physiology, including immune regulation, and is predictive of outcomes in cancer patients. However, whether conventional myelosuppressive chemotherapy affects the gut microbiota in humans with non-haematological malignancy, independent of antibiotic exposure, is unknown. Faecal s les from 19 participants with non-haematological malignancy, who were receiving conventional chemotherapy regimens but not antibiotics, were examined prior to chemotherapy, 7–12 days after chemotherapy, and at the end of the first cycle of treatment. Gut microbiota ersity and composition was determined by 16S rRNA gene licon sequencing. Compared to pre-chemotherapy s les, s les collected 7–12 days following chemotherapy exhibited increased richness (mean 120 observed species ± SD 38 vs 134 ± 40 p = 0.007) and ersity (Shannon ersity: mean 6.4 ± 0.43 vs 6.6 ± 0.41 p = 0.02). Composition was significantly altered, with a significant decrease in the relative abundance of gram-positive bacteria in the phylum Firmicutes (pre-chemotherapy median relative abundance [IQR] 0.78 [0.11] vs 0.75 [0.11] p = 0.003), and an increase in the relative abundance of gram-negative bacteria (Bacteroidetes: median [IQR] 0.16 [0.13] vs 0.21 [0.13] p = 0.01 and Proteobacteria: 0.015 [0.018] vs 0.03 [0.03] p = 0.02). Differences in microbiota characteristics from baseline were no longer significant at the end of the chemotherapy cycle. Conventional chemotherapy results in significant changes in gut microbiota characteristics during the period of predicted myelosuppression post-chemotherapy. Further study is indicated to link microbiome changes during chemotherapy to clinical outcomes.
Publisher: American Society of Parasitologists
Date: 06-2015
DOI: 10.1645/14-705.1
Abstract: Toxoplasma gondii is a protozoal parasite with worldwide distribution that is able to infect a wide variety of mammals and birds. Our main goal was to screen for T. gondii antibody titers in a previously untested species, the spotted hyena ( Crocuta crocuta) however, this goal first required us to investigate serological procedures that could be suitable for hyenas. Cats are the closest domestic relations of hyenas, so T. gondii antibody titers were first compared in 26 feral cats with specific or nonspecific fluorophore-labeled secondary reagents, i.e., anti-cat IgG or protein A. Substitution of anti-cat IgG with protein A caused a statistically significant drop in titer measurements in cats (P = 0.01) with a reduction of the geometric mean titer equivalent to 1 doubling-dilution. The same procedures were then applied to captive spotted hyenas. Titers measured in 9 of 10 hyenas were identical whether anti-cat IgG or protein A was used as the secondary reagent: 5 had titers <1:16, 2 had titers of 1:16, and 2 had titers of 1:32. One hyena had maximum titers of 1:64 or 1:32 when anti-cat IgG or protein A was used, respectively. The use of protein A as the secondary reagent in serologic assays can be applied to a range of mammalian species and seems unlikely to affect test specificity however, the use of protein A may reduce test sensitivity, as suggested in the present study using cats. Despite a control program, some exposure to T. gondii had occurred in the Zoo's spotted hyenas.
Publisher: SAGE Publications
Date: 16-09-2014
Abstract: The diagnosis of neonatal and young calves persistently infected (PI) with Bovine viral diarrhea virus (BVDV) by antigen-capture enzyme-linked immunosorbent assay (ACE) may be complicated by interference from colostrum-derived specific antibodies. Ten calves, with 3 calves identified as PI and 7 as non-PI were used in the current study. All non-PI calves were shown to be seropositive for BVDV-specific antibodies by antibody enzyme-linked immunosorbent assay (Ab-ELISA) on serum. Serum s les, ear notch s les, and nasal and saliva swabs were collected from each calf from birth until 12 weeks of age and tested by ELISA for BVDV-specific antigen and antibodies. Following colostrum ingestion, Ab-ELISA s le-to-positive (S/P) ratios rose by a mean of 0.95 (95% confidence interval [CI] = 0.64–1.25) and 1.72 (95% CI = 1.55–1.89) in seropositive, non-PI calves and in PI calves, respectively. The mean S/P ratios then declined to approximately 1.1 in non-PI calves and 0.5 in PI calves at between 60 and 80 days of age. In PI calves, testing for antigen in serum and nasal and saliva swabs was subject to interference by colostrum-derived antibodies in calves up to 3 weeks of age. Nasal swabs were less affected than serum and saliva swabs. Ear notches maintained positive ACE corrected optical densities at all s le times, despite a drop in the signal following the ingestion of colostrum.
Publisher: Elsevier BV
Date: 02-2015
Publisher: IWA Publishing
Date: 19-09-2017
DOI: 10.2166/WH.2017.241
Abstract: Moringa oleifera seeds are well known for their ability to cause flocculation in turbid water and facilitate bacterial inhibition. These effects are due to the cationic polypeptide MO2.1, which affects the surface charge of suspended particles and causes lysis of bacterial cells. However, the attachment of bacteria to MO2.1 prevents further bacterial attachment, reducing the effectiveness of the seeds. This research investigated the effect of surfactants on functionality and reuse of Moringa seeds to develop a sustainable water treatment technique. The seed extracts (MO2.1) were used with a functionalised sand system, and the sands were exposed to commercially available (ionic and non-ionic) surfactants, dodecyl glucoside and sodium dodecyl sulfate. Artificially polluted water contaminated with Escherichia coli was used to evaluate the efficiency of the system. The non-ionic surfactant was found to be effective at separating E. coli from the functionalised sand without the detachment of the MO2.1 and subsequent loss of the system efficiency. This was successfully repeated four times. The results demonstrated a sustainable, reusable technique to inhibit bacterial contamination in water.
Location: Australia
No related grants have been discovered for Sarah Sims.