Publications by authors named "Verner-Jeffreys D"

Article Synopsis
  • The study aimed to establish epidemiological cut-off values for the minimum inhibitory concentrations (MICs) of 10 antimicrobial agents against the bacteria Vibrio parahaemolyticus using standardized testing methods.
  • Eight laboratories conducted broth microdilution tests at two different temperatures (35°C and 28°C) to assess the effect of incubation temperature on MIC values, finding that many values were consistent across both temperatures.
  • The generated data will be submitted to the Clinical and Laboratory Standards Institute to help set international standards for interpreting antimicrobial susceptibility tests for this species.
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The Clinical and Laboratory Standards Institute has published epidemiological cut-off values for susceptibility data generated at 22°°C and read after 44-48 h for florfenicol, oxolinic acid and oxytetracycline against Aeromonas salmonicida. The cut-off values for the minimum inhibitory concentration (MIC) and disc diffusion were derived from data obtained by 1 laboratory and 2 laboratories respectively. The present work reports the generation of susceptibility data from additional laboratories and the calculation of provisional cut-off values from aggregations of these data with previously published data.

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One Health is a recognition of the shared environment inhabited by humans, animals and plants, and the impact of their interactions on the health of all organisms. The COVID-19 pandemic highlighted the need for a framework of pathogen surveillance in a tractable One Health paradigm to allow timely detection and response to threats to human and animal health. We present case studies centered around the recent global approach to tackle antimicrobial resistance and the current interest in wastewater testing, with the concept of "one sample many analyses" to be further explored as the most appropriate means of initiating this endeavor.

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In order to establish the meaning of data generated in antimicrobial agent susceptibility tests, it is necessary to develop internationally harmonised interpretive criteria. Currently, such criteria have not been developed for data generated in studies of the susceptibility of the fish pathogen Yersinia ruckeri. This work generated the data that would be required to set epidemiological cut-off values for the susceptibility data of this species that had been generated using a standardised disc diffusion method that specified the use of Mueller Hinton agar and incubation at 22°C for 24-28 h.

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Wet markets in low-and middle-income countries are often reported to have inadequate sanitation resulting in fecal contamination of sold produce. Consumption of contaminated wet market-sourced foods has been linked to individual illness and disease outbreaks. This pilot study, conducted in two major wet markets in Dhaka city, Bangladesh during a 4-month period in 2021 aimed to assess the occurrence and characteristics of and non-typhoidal spp.

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This work aims to generate the data needed to set epidemiological cut-off values for minimum inhibitory concentration (MIC) and disc-diffusion zone measurements of Vibrio anguillarum. A total of 261 unique isolates were tested, applying standard methods specifying incubation at 28°C for 24-28 h. Aggregated MIC distributions for a total of 247 isolates were determined in 9 laboratories for 11 agents.

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Article Synopsis
  • Bacteria from a specific family are linked to mass mortality events in farmed Pacific oysters in various countries, significantly affecting the industry.
  • In Ireland, certain bacteria are noted for causing serious summer outbreaks, with one pathogen emerging as the primary concern.
  • Research involved sequencing 43 bacterial isolates from oyster mortality cases, revealing two major clades that are likely spreading between Ireland and France, highlighting a risk to Pacific oyster production in Europe.
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While both virulent and putatively avirulent Yersinia ruckeri strains exist in aquaculture environments, the relationship between the distribution of virulence-associated factors and de facto pathogenicity in fish remains poorly understood. Pan-genome analysis of 18 complete genomes, representing established virulent and putatively avirulent lineages of Y. ruckeri, revealed the presence of a number of accessory genetic determinants.

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Tilapia farming is one of the most important sectors in aquaculture worldwide and of major importance to global food security. Infectious spleen and kidney necrosis virus (ISKNV) has been identified as an agent of high morbidity and mortality, threatening tilapia aquaculture. ISKNV was detected in Lake Volta, Ghana, in September 2018 and spread rapidly, with mortality rates between 60 and 90% and losses of more than 10 tonnes of fish per day.

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The World Health Organization considers antimicrobial resistance as one of the most pressing global issues which poses a fundamental threat to human health, development, and security. Due to demographic and environmental factors, the marine environment of the Gulf Cooperation Council (GCC) region may be particularly susceptible to the threat of antimicrobial resistance. However, there is currently little information on the presence of AMR in the GCC marine environment to inform the design of appropriate targeted surveillance activities.

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Intricate links between aquatic animals and their environment expose them to chemical and pathogenic hazards, which can disrupt seafood supply. Here we outline a risk schema for assessing potential impacts of chemical and microbial hazards on discrete subsectors of aquaculture-and control measures that may protect supply. As national governments develop strategies to achieve volumetric expansion in seafood production from aquaculture to meet increasing demand, we propose an urgent need for simultaneous focus on controlling those hazards that limit its production, harvesting, processing, trade and safe consumption.

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The development of effective vaccines is a critical step towards the domestication of emerging fish species for aquaculture. However, traditional vaccine delivery through intraperitoneal (i.p.

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Genetic resistance to infectious pancreatic necrosis virus (IPNV) in Atlantic salmon is a rare example of a trait where a single locus (QTL) explains almost all of the genetic variation. Genetic marker tests based on this QTL on salmon chromosome 26 have been widely applied in selective breeding to markedly reduce the incidence of the disease. In the current study, whole genome sequencing and functional annotation approaches were applied to characterise genes and variants in the QTL region.

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Atypical Aeromonas salmonicida (aAs) is currently one of the most routinely recovered bacterial pathogens isolated during disease outbreaks in farmed cleaner fish, ballan wrasse (Labrus bergylta, Ascanius). Vibrionaceae family bacteria have also been isolated from ballan wrasse in Scotland. This study determined the infectivity, pathogenicity and virulence of aAs and Vibrionaceae isolates in juvenile farmed ballan wrasse (n = 50; approx.

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Atypical Aeromonas salmonicida (aAs) and Vibrionaceae related species are bacteria routinely recovered from diseased ballan wrasse used as cleaner fish in the Atlantic salmon farming industry. Autogenous (i.e.

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In late 2018, unusual patterns of very high mortality (>50% production) were reported in intensive tilapia cage culture systems across Lake Volta in Ghana. Samples of fish and fry were collected and analysed from two affected farms between October 2018 and February 2019. Affected fish showed darkening, erratic swimming and abdominal distension with associated ascites.

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Here, we report the complete genome of piscine 01173 serotype Ia, which was generated using long-read sequencing technology. The bacteria were isolated from wild fish displaying signs of streptococcosis, from a fish kill incident in Kuwait.

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Aquaculture is predicted to supply the majority of aquatic dietary protein by 2050. For aquaculture to deliver significantly enhanced volumes of food in a sustainable manner, appropriate account needs to be taken of its impacts on environmental integrity, farmed organism health and welfare, and human health. Here, we explore increased aquaculture production through the One Health lens and define a set of success metrics - underpinned by evidence, policy and legislation - that must be embedded into aquaculture sustainability.

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is the causative agent of vibriosis in many species important to aquaculture. We generated whole genome sequence (WGS) data on a diverse collection of 64 strains, which we supplemented with 41 publicly available genomes to produce a combined dataset of 105 strains. These WGS data resolved six major lineages (L1-L6), and the additional use of multilocus sequence analysis (MLSA) clarified the association of L1 with serotype O1 and hosts (salmon/trout), and L2 with serotypes O2a/O2b/O2c and hosts (cod).

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Article Synopsis
  • Antimicrobial resistance (AMR) is a rising public health threat linked to the excessive use of antibiotics in shrimp farming, especially in low- and middle-income countries with lax regulations.
  • The integration of aquaculture with local livelihoods and the direct release of untreated waste into water sources contribute to this risk.
  • Addressing AMR in shrimp farming is complex due to challenges in tracking antibiotic usage and the reliance on these drugs for disease control, highlighting the need for improved practices and mitigation strategies for a sustainable shrimp industry.
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Article Synopsis
  • - Wild-caught ballan wrasse from the British south-west coast are being moved to Scotland to help control sea lice on Atlantic salmon, but their health status was largely unknown prior to this study.
  • - A health assessment conducted on 75 ballan wrasse revealed various parasites, including copepods, nematodes, and opportunistic pathogens, with some fish showing signs of infection.
  • - Although no urgent health issues were found that would impact the wrasse's mass migration, the study recommends ongoing monitoring of the population to ensure their well-being.
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Article Synopsis
  • A new typing system using variations in the vapA gene allows accurate subtyping of Aeromonas salmonicida from different fish species and locations.
  • The study analyzed 675 isolates over 59 years, identifying nine new A-layer types linked to specific fish hosts like Cyprinidae and Pleuronectidae.
  • Findings suggest human activities have helped spread certain A-layer types, and a public database is available for accessing the data, highlighting the significance of vapA for understanding the global distribution and host associations of this pathogen.
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  • - Renibacterium salmoninarum causes bacterial kidney disease (BKD) in farmed salmon, posing a major issue for the salmon industry.
  • - Whole-genome sequencing of 42 R. salmoninarum isolates in Chile reveals multiple introductions and rapid spread of the disease over 30 years, aligning with aquaculture development events.
  • - The study identifies significant barriers to BKD transmission and suggests insights into the pathogen's host preferences, which could help in developing better disease management strategies for the salmon industry.
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