Renibacterium salmoninarum iron‐acquisition mechanisms and ASK cell line infection: Virulence and immune response

Renibacterium salmoninarum is the aetiological agent of bacterial kidney disease (BKD) in salmonid farms. This pathogen possesses at least three iron‐acquisition mechanisms, but the link between these mechanisms and virulence is unclear. Therefore, this study used RT‐qPCR to assess the effects of normal and iron‐limited conditions on iron‐uptake genes controlled by IdeR and related to iron acquisition in Chilean R. salmoninarum strain H‐2 and the type strain DSM20767^T. Further evaluated was the in vitro immune‐related response of the Atlantic Salmon Kidney (ASK) cell line, derived from the primary organ affected by BKD. R. salmoninarum grown under iron‐limited conditions overexpressed genes involved in haemin uptake and siderophore transport, with overexpression significantly higher in H‐2 than DSM20767^T. These overexpressed genes resulted in higher cytotoxicity and an increased immune response (i.e., TNF‐α, IL‐1β, TLR1 and INF‐γ) in the ASK cell line. This response was significantly higher against bacteria grown under iron‐limited conditions, especially H‐2. These observations indicate that iron‐acquisition mechanisms are possibly highly related to the virulence and pathogenic capacity of R. salmoninarum. In conclusion, treatments that block iron‐uptake mechanisms or siderophore synthesis are attractive therapeutic approaches for treating R. salmoninarum, which causes significant aquaculture losses.     

Aligning landscape structure with ecosystem services along an urban–rural gradient. Trade-offs and transitions towards cultural services

Landscape Ecology - Urban–rural gradients provide a suitable framework for studying the provision of urban and rural ecosystem services (ES), linked to social welfare. Landscape structure...     

New Zealand perspective on ISO 17025 accreditation of a plant diagnostic laboratory1

Four plant diagnostic laboratories in New Zealand have obtained ISO 17025 accreditation since 2001: Linnaeus Laboratory; PestLab, AsureQuality Ltd; Horticulture and Food Research Institute of New Zealand Ltd; and the Ministry of Agriculture and Forestry's (MAF) Plant Health and Environment Laboratory (PHEL). The challenge of pursuing ISO 17025 accreditation for PHEL emerged in late 2003 when a review of a MAF diagnostic standard made ISO 17025 accreditation a mandatory requirement for approval. The accreditation project took three years from initiation to accreditation in 2007. The scope of PHEL's accreditation covers tests (e.g. PCR, RT‐PCR, or ELISA) for the Carlavirus group, High plains virus, Iris yellow spot virus, Pepino mosaic virus, Plum pox virus, Raspberry ringspot virus, phytoplasmas, Potato spindle tuber viroid, and Xylella fastidiosa and morphological identifications of fungi and invertebrates. This article provides a brief overview of ISO 17025 accreditation of plant diagnostic laboratories in New Zealand, describes PHEL's scope of accreditation, and discusses some of the issues and challenges PHEL faced during the process of attaining accreditation and still faces post‐accreditation.     

Pikeperch (Sander lucioperca) spermatozoa motility and volume regulation under different osmotic and ionic conditions

Fish Physiology and Biochemistry - Pikeperch (Sander lucioperca) is a highly profitable commercial species whose economic value has greatly increased in the last decade. As in other species, the...