Conference Posters

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7703

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Start date: 2020End date: 2023

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Now showing 1 - 6 of 6
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    Environmental drivers of antimicrobial resistance – cadmium contamination & antibiotic resistance in soil samples from a rural airstrip.
    (2023-12-05) Heydari A; Kim N; Biggs P; Horswell J; Gielen G; Siggins A; Bromhead C; Palmer B
    Environmental contamination with both inorganic and organic compounds is a growing problem globally. In this study we investigated links between heavy metal contamination of soil and selection for antibiotic resistance in soil bacteria. Soil samples taken at 10 m intervals along the length of a 70 m transect of a rural airstrip used for aerial topdressing located in Belmont Regional Park near Wellington were analysed for heavy metal content and resistance profiles of heterotrophic bacteria cultured were characterised. A gradient of cadmium contamination (a known contaminant of superphosphate fertiliser) ranging from 1.14 to 7.20 mg kg-1 of dry soil was detected in the samples. Total bacterial counts were significantly reduced at the most heavily contaminated subsites, with >60% of isolates resistant to 0.01 mM CdCl2. The ratio of antibiotic resistant isolates to total CFU was significantly higher at the most contaminated compared to the least contaminated subsite for five common antibiotics. Metagenomic analysis of total DNA from three subsites showed significantly different profiles at all taxonomic levels. This suggests environmental contamination with heavy metals may be a significant and under-appreciated driver of selection for antimicrobial resistance.
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    Prevalence of liver fluke on West Coast farms of the South Island of New Zealand sampled in the autumn and spring of consecutive lactations
    (2021-07-19) Dowling A; Pomroy W; Howe L; Scott I; Lawrence K
    The aim of this study was to determine the occurrence of Fasciola hepatica infection in dairy cows in this West Coast of the South Island using an ELISA of bulk milk samples (n=430) collected on one of two occasions during March (autumn) 2017 and again in October (spring). All samples were analysed using the IDEXX Fasciolosis Verification kit which estimates the infection level in the herd in 4 categories; >50% infestation (strong); 20-50% infestation (medium); <20% infestation (low); no infection. A subset (n=99) were tested twice with a one week interval to determine repeatability. A short survey was also posted to each supplier with 157 completed. Of the 430 farms tested 133 (31%) were negative, 49 (11%) had a low infestation, 62 (14%) had a medium infestation and 186 (43%) had a strong infestation. GIS mapping of the farm locations indicated geographic grouping of farms with more severe fluke infestations. The 99 samples tested twice substantially agreed (Kappa = 0.7). Farms tested in both autumn and spring (n= 369) moderately agreed (Kappa 0.43) with an overall decrease in the spring. From the survey 85% of farmers were aware of liver fluke on their farm during the last 5 years and 70% treated their cows with a flukicide during the dry period (winter) including 92% of the farms that tested negative. This study indicates fasciolosis is common in this region with a disturbing number with a high prevalence in their herds. It also showed a decrease from autumn to following spring levels.
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    Acceptability of LGBTQ-Affirmative Cognitive Behavioral Group Therapy for Youth: Results from a Pilot Study
    (2023-04-01) Seager van Dyk I; Layland EK; Soulliard ZA; Pachankis JE
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    A genetic approach to identify amino acids in Gcn1 required for Gcn2 activation (poster)
    (8/09/2022) Schiemann A; Gottfried S; Sattlegger E
    The General Amino Acid Control stress signalling pathway allows cells to sense and overcome starvation. One of the major players in this pathway is the protein kinase Gcn2 found in all eukaryotic cells. Activation of Gcn2 leads to phosphorylation of the alpha subunit of eukaryotic translation initiation factor (eIF2α), which then leads to the re-programming of the cell’s gene transcription and translation profile, and ultimately allowing cells to cope with and overcome starvation. For sensing starvation, Gcn2 must directly bind to its effector protein Gcn1. This interaction is mediated via a region in Gcn1 called the RWD binding domain (RWDBD). Overexpression of the RWDBD alone impairs Gcn2 activation through disrupting endogenous Gcn1-Gcn2 interaction, hampering eIF2α phosphorylation, and consequently cells cannot overcome starvation and fail to grow.  This dominant negative phenotype is dependent on Arg-2259 in RWDBD.  Taking advantage of this phenotype in yeast, we here found that the dominant negative phenotype was reverted by each of four amino acid substitutions, K2270A, R2289A, R2297A, and K2301A.  This correlated with increased eIF2α phosphorylation levels, suggesting their relevance for Gcn2 activation.  All but Lys-2270 are fully surface exposed, suggesting that these amino acids may directly contact Gcn2.  We also found amino acid substitutions that enhanced the dominant negative phenotype of the overexpressed RWDBD, and correlated with further reduction in eIF2α-P levels.  Our findings suggest that two helices in Gcn1 constitute at least one Gcn2 contact point.
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