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Povzetek: Expanding international pet trade has emerged as one of the main introduction pathways of aquatic invasive species, with ornamental crayfish species commonly available on the EU and global markets. Besides most frequently studied crayfish pathogens, such as Aphanomyces astaci and white spot syndrome virus (WSSV), ornamental crayfish carry associated microbial communities, which may potentially lead to the emergence of known or even novel diseases following intentional or unintentional release of animals into the wild. This is especially problematic in the case of viruses, which represent an important, yet considerably understudied, group of crayfish pathogens. Here we analyzed viromes of hepatopancreas tissue of four crayfish species acquired in the international pet trade in Europe (Procambarus clarkii, Procambarus alleni, Cherax holthuisi, and Cherax quadricarinatus) using a high throughput sequencing based metagenomic approach. Seven different known viruses were identified, which were previously either directly associated with crayfish (WSSV, Cherax quadricarinatus reovirus, chequa iflavirus, athtab bunya-like virus) or with hosts from subphylum Crustacea or invertebrates associated with freshwater environment (Shahe ispoda virus 5, Dicistroviridae sp.). Additional sequences represented 8 potential novel and divergent RNA viruses, most similar to sequences belonging to members of Picornavirales, Elliovirales, Reovirales, Hepelivirales, Tolivirales and Ghabrivirales orders. We discuss our findings in relation to their phylogenetic relationships, geographical origins, and putative pathogenicity implications. The results highlight the need for further research into the risks related to disease emergence associated with the pet trade.
Ključne besede: virome, RNA viruses, ornamental crayfish, pet-trade, high throughput sequencing, ecology, molecular biology, pathology, virology, environmental risk assessment
Objavljeno v DiRROS: 23.05.2025; Ogledov: 263; Prenosov: 168
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Ključne besede: ToBRFV, ToMMV, tobamovirusi, epidemiologija, voda kot vir okužb, poročila
Objavljeno v DiRROS: 28.11.2024; Ogledov: 469; Prenosov: 591
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Povzetek: Water can be an important source of plant pathogenic viruses. Usually they are present in low concentrations, but environmental waters still represent a potential pathway for virus transmission. Already over 30 years ago, plant viruses have been shown to be present in environmental waters in considerable amounts (Koenig, 1986). Since then, many questions concerning the origin, survival, and spread of plant viruses by water have been raised, especially in the light of increased irrigation and use of hydroponic systems in agriculture (Mehle and Ravnikar 2012). The majority of the plant pathogenic viruses recovered from environmental waters so far are very stable. They can infect plants via the roots without the aid of a vector and often have a wide host range (Mehle and Ravnikar 2012). The release of such viruses from plants can lead to their diffusion in streams, rivers and lakes, thereby ensuring the long-distance spread of viruses that would otherwise remain restricted to limited areas (Mehle et al., 2014; Mehle and Ravnikar, 2012).
Objavljeno v DiRROS: 03.09.2024; Ogledov: 495; Prenosov: 214
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Povzetek: Dickeya fangzhongdai, an aggressive plant pathogen, causes symptoms on a variety of crops and ornamental plants including bleeding canker of Asian pear trees. Historical findings stress the need for a specific detection tool for D. fangzhongdai to prevent overlooking the pathogen or assigning it to general Dickeya spp. Therefore, a qualitative real-time PCR for specific detection of D. fangzhongdai has been developed and validated. The developed assay shows selectivity of 100%, diagnostic sensitivity of 76% and limit of detection with 95% confidence interval in plant matrices ranging from 311 to 2,275 cells/mL of plant extracts. The assay was successfully used in a retrospective survey of selected host plants of relevance to Europe and environmental niches relevant to D. fangzhongdai. Samples of potato tubers and plants, plants from the Malinae subtribe (apple, pear, quince, and Asian pear tree) and fresh surface water from Slovenia were analyzed. D. fangzhongdai was not detected in any plant samples, however, 12% of surface water samples were found to be positive.
Ključne besede: molecular testing, diagnostics, plant pathogen, real-time PCR, Dickeya, survey, water
Objavljeno v DiRROS: 07.08.2024; Ogledov: 618; Prenosov: 383
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Povzetek: Crayfish are a keystone species of freshwater ecosystems and a successful invasive species. However, their pathogens, including viruses, remain understudied. The aim of this study was to analyze the virome of the invasive signal crayfish (Pacifastacus leniusculus) and to elucidate the potential differences in viral composition and abundance along its invasion range in the Korana River, Croatia. By the high-throughput sequencing of ribosomal RNA, depleted total RNA isolated from the crayfish hepatopancreas, and subsequent sequence data analysis, we identified novel and divergent RNA viruses, including signal crayfish-associated reo-like, hepe-like, toti-like, and picorna-like viruses, phylogenetically related to viruses previously associated with crustacean hosts. The patterns of reads abundance and calculated nucleotide diversities of the detected viral sequences varied along the invasion range. This could indicate the possible influence of different factors and processes on signal crayfish virome composition: e.g., the differences in signal crayfish population density, the non-random dispersal of host individuals from the core to the invasion fronts, and the transfer of viruses from the native co-occurring and phylogenetically related crayfish species. The study reveals a high, previously undiscovered diversity of divergent RNA viruses associated with signal crayfish, and sets foundations for understanding the potential risk of virus transmissions as a result of this invader’s dispersal.
Ključne besede: signal crayfish virome, RNA viruses, invasive alien species, invasion range, high-throughput sequencing
Objavljeno v DiRROS: 19.07.2024; Ogledov: 736; Prenosov: 368
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