Journal Articles

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Author: search.filters.author.Brightwell G

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    Population dynamics of Campylobacter jejuni in healthy dairy calves reared with and without exposure to wild birds
    (Oxford University Press on behalf of Applied Microbiology International, 2025-12-01) Rapp D; Ross CM; Tegetmeyer HE; Maclean P; French NP; Brightwell G
    Introduction In order to understand the emergence, persistence, and transmission of Campylobacter jejuni in livestock, this longitudinal study characterized the C. jejuni population in young calves and assessed the impact of exposure to wild birds during the pre-weaning period. Methods and results Faecal samples were collected on eight occasions from 48 calves housed in three pens between birth and 10 weeks of age, two of the pens being covered with orchard netting. From the 250 C. jejuni isolates obtained from the positive faeces, seven distinct sequence types (7-gene legacy MLST) were identified, with high genetic similarity of circulating strains. On each pen, sequential dominance of ST was observed, with ST-508 and ST-50 prevalent in calves under 4 weeks old, and ST-520 or ST-422 prevalent in the 8- to 10-week-old calves. Exposure of calves to wild birds did not influence genotypes distribution, α-diversity, and community dissimilarity. However, a difference in C. jejuni populations between the two groups of calves that were not exposed to birds suggests that calving rank may shape the type and succession of ST detected over time. Conclusion This study provided no evidence for exposure to wild birds being a driver for C. jejuni population changes in healthy pre-weaned calves.
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    Fecal excretion of Campylobacter jejuni by young dairy calves and the relationship with neonatal immunity and personality traits
    (Oxford University Press on behalf of Applied Microbiology International, 2023-04-29) Rapp D; Schütz KE; Ross C; Sutherland MA; Hempstead MN; Hannaford R; Cave VM; Brightwell G
    Aims Zoonotic pathogens in bovine herds are major concerns for human and animal health, but their monitoring in animals can be challenging in the absence of clinical signs. Our objective was to determine the association between fecal excretion of Campylobacter jejuni, neonatal immunity, and personality traits of calves. Methods and results Forty-eight dairy calves were reared in three indoor pens from birth to 4 weeks of life. Microbial analyses of the fecal samples collected weekly revealed that the proportion of calves naturally contaminated with C. jejuni in each pen reached 70% after 3 weeks of life. High (>16 g l−1) levels of IgG levels in the serum of neonatal calves were negatively (P = .04) associated with fecal detection of C. jejuni over the trial period. Calves that spent more time interacting with a novel object tended to be positive (P = .058) for C. jejuni. Conclusions Overall, the findings indicate that the immunity of neonatal dairy animals and possibly the animal’s behavior may contribute to the fecal shedding of C. jejuni.
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    New Campylobacter Lineages in New Zealand Freshwater: Pathogenesis and Public Health Implications
    (John Wiley and Sons, 2024-12) Cookson AL; Burgess S; Midwinter AC; Marshall JC; Moinet M; Rogers L; Fayaz A; Biggs PJ; Brightwell G
    This study investigated the diversity of thermophilic Campylobacter species isolated from three New Zealand freshwater catchments affected by pastoral and urban activities. Utilising matrix-assisted laser desorption ionisation-time of flight and whole genome sequence analysis, the study identified Campylobacter jejuni (n = 46, 46.0%), C. coli (n = 39, 39%), C. lari (n = 4, 4.0%), and two novel Campylobacter species lineages (n = 11, 11%). Core genome sequence analysis provided evidence of prolonged persistence or continuous faecal shedding of closely related strains. The C. jejuni isolates displayed distinct sequence types (STs) associated with human, ruminant, and environmental sources, whereas the C. coli STs included waterborne ST3302 and ST7774. Recombination events affecting loci implicated in human pathogenesis and environmental persistence were observed, particularly in the cdtABC operon (encoding the cytolethal distending toxin) of non-human C. jejuni STs. A low diversity of antimicrobial resistance genes (aadE-Cc in C. coli), with genotype/phenotype concordance for tetracycline resistance (tetO) in three ST177 isolates, was noted. The data suggest the existence of two types of naturalised waterborne Campylobacter: environmentally persistent strains originating from waterbirds and new environmental species not linked to human campylobacteriosis. Identifying and understanding naturalised Campylobacter species is crucial for accurate waterborne public health risk assessments and the effective allocation of resources for water quality management.
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    Assessing antimicrobial resistance in pasture-based dairy farms: a 15-month surveillance study in New Zealand.
    (American Society for Microbiology, 2024-10-23) Collis RM; Biggs PJ; Burgess SA; Midwinter AC; Liu J; Brightwell G; Cookson AL
    Antimicrobial resistance is a global public and animal health concern. Antimicrobial resistance genes (ARGs) have been detected in dairy farm environments globally; however, few longitudinal studies have utilized shotgun metagenomics for ARG surveillance in pasture-based systems. This 15-month study aimed to undertake a baseline survey using shotgun metagenomics to assess the relative abundance and diversity of ARGs in two pasture-based dairy farm environments in New Zealand with different management practices. There was no statistically significant difference in overall ARG relative abundance between the two dairy farms (P = 0.321) during the study period. Compared with overseas data, the relative abundance of ARG copies per 16S rRNA gene in feces (0.08-0.17), effluent (0.03-0.37), soil (0.20-0.63), and bulk tank milk (0.0-0.12) samples was low. Models comparing the presence or absence of resistance classes found in >10% of all feces, effluent, and soil samples demonstrated no statistically significant associations (P > 0.05) with "season," and only multi-metal (P = 0.020) and tetracycline (P = 0.0003) resistance were significant at the "farm" level. Effluent samples harbored the most diverse ARGs, some with a recognized public health risk, whereas soil samples had the highest ARG relative abundance but without recognized health risks. This highlights the importance of considering the genomic context and risk of ARGs in metagenomic data sets. This study suggests that antimicrobial resistance on pasture-based dairy farms is low and provides essential baseline ARG surveillance data for such farming systems. IMPORTANCE: Antimicrobial resistance is a global threat to human and animal health. Despite the detection of antimicrobial resistance genes (ARGs) in dairy farm environments globally, longitudinal surveillance in pasture-based systems remains limited. This study assessed the relative abundance and diversity of ARGs in two New Zealand dairy farms with different management practices and provided important baseline ARG surveillance data on pasture-based dairy farms. The overall ARG relative abundance on these two farms was low, which provides further evidence for consumers of the safety of New Zealand's export products. Effluent samples harbored the most diverse range of ARGs, some of which were classified with a recognized risk to public health, whereas soil samples had the highest ARG relative abundance; however, the soil ARGs were not classified with a recognized public health risk. This emphasizes the need to consider genomic context and risk as well as ARG relative abundance in resistome studies.
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    Whole-Genome Sequencing of Clostridium sp. Strain FP2, Isolated from Spoiled Venison.
    (American Society for Microbiology, 2020-04-30) Palevich N; Palevich FP; Maclean PH; Jauregui R; Altermann E; Mills J; Brightwell G; Cuomo CA
    Clostridium sp. strain FP2 was isolated from vacuum-packaged refrigerated spoiled venison in New Zealand. This report describes the generation and annotation of the 5.6-Mb draft genome sequence of Clostridium sp. FP2, which will facilitate future functional genomic studies to improve our understanding of premature spoilage of red meats.
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    Draft Genome Sequence of Clostridium bowmanii DSM 14206T, Isolated from an Antarctic Microbial Mat.
    (American Society for Microbiology, 2022-01-20) Palevich FP; Palevich N; Maclean PH; Altermann E; Mills J; Brightwell G; Gill SR
    Clostridium bowmanii type strain DSM 14206 (ATCC BAA-581) was isolated from a microbial mat sample retrieved from Lake Fryxell, Antarctica. This report describes the generation and annotation of the 4.9-Mb draft genome sequence of C. bowmanii DSM 14206T.
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    Draft Genome Sequence of Clostridium sp. Strain FP1, with Similarity to Clostridium tagluense, Isolated from Spoiled Lamb.
    (American Society for Microbiology, 2020-04-30) Palevich N; Palevich FP; Maclean PH; Jauregui R; Altermann E; Mills J; Brightwell G; Hotopp JCD
    Clostridium sp. strain FP1 was isolated from vacuum-packaged refrigerated spoiled lamb, and this article describes its 5.4-Mb draft genome sequence. The FP1 genome was sequenced to facilitate source tracking and attribution studies, adding to our understanding of the role of Clostridium species in premature spoilage of red meats.
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    Draft Genome Sequence of Clostridium estertheticum-like Strain FP4, Isolated from Spoiled Uncooked Lamb.
    (American Society for Microbiology, 2020-05-07) Palevich N; Palevich FP; Maclean PH; Jauregui R; Altermann E; Mills J; Brightwell G; Rasco D
    In order to improve the phylogenetic resolution of the genus Clostridium and our limited knowledge of meat spoilage caused by Clostridium estertheticum, the genome of C. estertheticum-like strain FP4 was sequenced. Here, we describe the 4.1-Mb draft genome sequence of C. estertheticum-like strain FP4, isolated from vacuum-packaged refrigerated spoiled lamb.
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    Draft Genome Sequence of Clostridium estertheticum-Like Strain FP3, Isolated from Spoiled Uncooked Lamb.
    (American Society for Microbiology, 2020-05-14) Palevich N; Palevich FP; Maclean PH; Jauregui R; Altermann E; Mills J; Brightwell G; Gill SR
    Clostridium estertheticum-like strain FP3 was isolated from vacuum-packaged refrigerated spoiled lamb. This bacterium is psychrotrophic, Gram positive, spore-forming, and a strict anaerobe. Here, we report the generation and annotation of the 5.6-Mb draft genome sequence of C. estertheticum-like strain FP3.
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    Draft Genome Sequence of Clostridium estertheticum subsp. laramiense DSM 14864T, Isolated from Spoiled Uncooked Beef.
    (American Society for Microbiology, 2019-11-21) Palevich N; Palevich FP; Maclean PH; Jauregui R; Altermann E; Mills J; Brightwell G; Newton ILG
    Clostridium estertheticum subsp. laramiense type strain DSM 14864 (ATCC 51254) was isolated from vacuum-packaged refrigerated spoiled beef. This report describes the generation and annotation of the 5.0-Mb draft genome sequence of C. estertheticum subsp. laramiense DSM 14864T.