Variety Of Hosts Research Articles

Key roles of two-component systems in intestinal signal sensing and virulence regulation in enterohemorrhagic Escherichia coli.

Enterohemorrhagic Escherichia coli (EHEC) is a foodborne pathogen that infects humans by colonizing the large intestine. Upon reaching the large intestine, EHEC mediates local signal recognition and the transcriptional regulation of virulence genes to promote adherence and colonization in a highly site-specific manner. Two-component systems (TCSs) represent an important strategy used by EHEC to couple external stimuli with the regulation of gene expression, thereby allowing EHEC to rapidly adapt to changing environmental conditions. An increasing number of studies published in recent years have shown that EHEC senses a variety of host- and microbiota-derived signals present in the human intestinal tract and coordinates the expression of virulence genes via multiple TCS-mediated signal transduction pathways to initiate the disease-causing process. Here, we summarize how EHEC detects a wide range of intestinal signals and precisely regulates virulence gene expression through multiple signal transduction pathways during the initial stages of infection, with a particular emphasis on the key roles of TCSs. This review provides valuable insights into the importance of TCSs in EHEC pathogenesis, which have relevant implications for the development of antibacterial therapies against EHEC infection.

New Genotype G3 P[8] of Rotavirus Identified in a Mexican Gastroenteric Rabbit

Rotavirus species A (RVA) is a major cause of acute viral gastroenteritis in young humans and diverse animal species. The study of the genetic characteristics of RVAs that infect rabbits (Oryctolagus cuniculus) (lapine strain [LRV]) has been limited, and, to date, the most common and epidemiologically important combinations of G/P genotypes in rabbits have been reported to be G3 P[14] and G3 P[22]. In this study, a rotavirus species A detected from an outbreak of enteritis in a Mexican commercial rabbitry was genotypically characterized. Based on sequence and phylogenetic analysis of the VP7 and VP4 genes, the strain identified in this study (C-3/15) demonstrated a G3 P[8] genotype of rotavirus, which had not previously been reported in rabbits. Moreover, both genes were closely related to human, not lapine, rotaviruses. The G3 genotype has been reported in a wide variety of hosts, including humans and rabbits, whereas the P[8] genotype has only been reported in humans. Because this combination of genotypes has never been identified in rabbits, it is proposed that the finding presented here is possibly the result of an interspecies transmission event. This is the first work to study the molecular characteristics of rotaviruses in rabbits in Mexico, as well as the identification of human G3 and P[8] genotypes in a rabbit with enteric disease.

A footworm in the door: revising Onchocerca phylogeny with previously unknown cryptic species in wild North American ungulates

Onchocerca is an important genus of vector-borne filarial nematodes that infect both humans and animals worldwide. Many Onchocerca spp., most of medical and veterinary health relevance, are the focus of a variety of diagnostic and molecular research. However, despite the importance of these parasites, there is growing evidence of previously unexplored genetic diversity of these nematodes, particularly among wild ungulate hosts in North America. These understudied parasites prevent us from comprehending the evolutionary history of the genus Onchocerca, monitoring potential One Health threats, and improving our filarioid diagnostic capabilities. In order to fill these knowledge gaps, we identified five uncharacterized Onchocerca lineages and compared them with other well-known filarioid species using single and concatenated gene regions (i.e., nd5, cox1, 12S, 18S, 28S, hsp70, MyoHC, rbp1). Phylogenetic analyses revealed that the novel Onchocerca lineages of wild North American ungulates segregate into two clades. One clade comprised Onchocerca lineages II, IV, and V and other species found mainly in domestic animals and humans, and the second comprised Onchocerca lineages I and III and other species from a variety of hosts including cervids, bovids, and equids. The formation of two clearly separate clades supports the idea of at least two independent expansion events of ancestral Onchocerca spp. into the North American continent via the Bering land bridge. Cophylogenetic analysis shows evidence of ancestral Onchocerca spp. of Bovidae host-switching to wild Cervidae and giving rise to the novel Onchocerca spp. Lastly, pairwise analysis confirms informative molecular markers of diagnostic relevance in both mitochondrial and nuclear gene regions of filarioid nematodes. The overall information provides greater context to the genus Onchocerca and emphasizes the need to discover, characterize, and monitor neglected parasites, especially those of wildlife origin.

Proteome profiling of polyomavirus nuclear replication centers using iPOND.

Polyomaviruses (PyVs) cause diverse diseases in a variety of mammalian hosts. During the life cycle, PyVs recruit nuclear host factors to viral genomes to facilitate replication and transcription. While host factors involved in DNA replication, DNA damage sensing and repair, and cell cycle regulation have been observed to bind PyV DNA, the complete set of viral and host proteins comprising the PyV replisome remains incompletely characterized. Here, the iPOND-MS technique (Isolation of Proteins on Nascent DNA coupled with Mass Spectrometry) was used to identify the proteome bound to murine PyV (MuPyV) DNA immediately following synthesis and 2 hours post-synthesis. Several novel MuPyV DNA interactors were identified on newly synthesized viral DNA (vDNA), including MCM complex members, DNA primase, DNA polymerase alpha, DNA ligase, and replication factor C. Though displaying partial overlap, the host and viral proteins bound to MuPyV DNA 2 hours post-synthesis lacked many of the replication proteins found on newly synthesized vDNA. These data help distinguish between the host factors critical for MuPyV DNA replication and those involved in downstream processing.IMPORTANCEPolyomaviruses are the causative agents of serious diseases in humans, including progressive multifocal leukoencephalopathy (PML), BK virus nephropathy, and Merkel cell carcinoma. The exact mechanisms by which the virus replicates, and which host cell proteins are required, are incompletely characterized. Identifying the host proteins necessary for efficient viral replication in the cell may reveal targets for downstream targets that may suppress viral replication in vivo.

Genomic insight on Klebsiella variicola isolated from wastewater treatment plant has uncovered a novel bacteriophage

Klebsiella variicola is considered an emerging pathogen, which may colonize a variety of hosts, including environmental sources. Klebsiella variicola investigated in this study was obtained from an influent wastewater treatment plant in the North-West Province, South Africa. Whole genome sequencing was conducted to unravel the genetic diversity and antibiotic resistance patterns of K. variicola. Whole genome core SNP phylogeny was employed on publicly available 170 genomes. Furthermore, capsule types and antibiotic resistance genes, particularly beta-lactamase and carbapenems genes were investigated from the compared genomes. A 38 099 bp bacteriophage was uncovered alongside with K. variicola genome. Whole genome sequencing revealed that the extended beta-lactamase blaLEN (75.3%) of the beta-lactamase is dominant among compared K. variicola strains. The identified IncF plasmid AA035 confers resistance genes of metal and heat element subtypes, i.e., silver, copper, and tellurium. The capsule type KL107-D1 is a predominant capsule type present in 88.2% of the compared K. variicola genomes. The phage was determined to be integrase-deficient consisting of a fosB gene associated with fosfomycin resistance and clusters with the Wbeta genus Bacillus phage group. In silico analysis showed that the phage genome interacts with B. cereus as opposed to K. variicola strain T2. The phage has anti-repressor proteins involved in the lysis-lysogeny decision. This phage will enhance our understanding of its impact on bacterial dissemination and how it may affect disease development and antibiotic resistance mechanisms in wastewater treatment plants. This study highlights the need for ongoing genomic epidemiological surveillance of environmental K. variicola isolates.

Influenza Virus Types, Subtypes and Genomic Lineage with Its Prevention and Control: A Narrative Review

Since influenza viruses continue to be a serious hazard to both humans and animals, they are still very important. Types A, B, and C influenza viruses are among the members of the Orthomyxoviridae family. A quick summary of the molecular factors is provided, which determine pathogenicity and clinical signs and symptoms of influenza. A review of host range and evolution highlights the genetic diversity of influenza A viruses and their capacity to successfully infect a variety of hosts, including avian and mammalian species. Moreover, influenza viruses may reassemble segments because of the way their segmented genome is designed. The significance of host sialic acid distribution and viral receptor-binding hemagglutinins in species-restricted virus binding is emphasized. It results in yearly outbreaks and necessitates the creation of novel vaccination formulations. This may ultimately result in the creation of a virus that can spread among humans and has unique antigenic qualities, perhaps sparking a pandemic. Current developments in our knowledge of the seasonality, transmission, and prevention of influenza viruses are outlined, along with their significance for halting the virus's spread. Journal of Monno Medical College June, 2024; 10 (1):43-51

Specific amino acid changes correlate with pathogenic flavobacteria.

Flavobacterium is a genus of microorganisms living in a variety of hosts and habitats across the globe. Some species are found in fish organs, and only a few, such as Flavobacteriumpsychrophilum and Flavobacterium columnare, cause severe disease and losses in fish farms. The evolution of flavobacteria that are pathogenic to fish is unknown, and the protein changes accountable for the selection of their colonization to fish have yet to be determined. A phylogenetic tree was constructed with the complete genomic sequences of 208 species of the Flavobacterium genus using 861 softcore genes. This phylogenetic analysis revealed clade CII comprising nine species, including five pathogenic species, and containing the most species that colonize fish. Thirteen specific amino acid changes were found to be conserved across 11 proteins within the CII clade compared with other clades, and these proteins were enriched in functions related to replication, recombination, and repair. Several of these proteins are known to be involved in pathogenicity and fitness adaptation in other bacteria. Some of the observed amino acid changes can be explained by preferential selection for certain codons and tRNA frequency. These results could help explain how species belonging to the CII clade adapt to fish environments.

Seroprevalence and assessment the associated risk factors for Fasciola hepatica infection in water buffaloes in Egypt.

Fasciolosis is a zoonotic neglected parasitic disease that affects a variety of hosts, resulting in substantial economic losses. The epidemiological information about fasciolosis in water buffaloes in Egypt is very scarce. Hence, the present study aimed to determine the seroprevalence of F. hepatica in water buffaloes using commercial ELISA kits in three governorates at north of Egypt and to estimate the associated risk factors for F. hepatica infection. The total seroprevalence of F. hepatica in buffaloes was 15.4% (63/410), with a higher seroprevalence in Kafr Elsheikh governorates 17.9% (25/140) than in other areas. Fasciolosis was more likely in older buffaloes (OR = 3.4, 95%CI:1.5-7.8), throughout the winter season (OR = 5.3, 95%CI:1.9-14.7). Moreover, the absence of prophylactic treatment (OR = 2.3, 95%CI:1.2-4.2) increased the risk of F. hepatica infection in buffaloes, particularly in animals suffered from diarrhea (OR = 3.8, 95%CI:1.4-10.6). The present study confirmed the prevalence of F. hepatica in water buffaloes in north of Egypt. Consequently, the implementation of preventive and control for the parasite and its intermediate host are very necessary to decrease the economic losses and public health hazard.

Redescription of Raillietiella mottae (Raillietiellidae: Pentastomida) a generalist parasite of insectivorous lizards: phenotypic plasticity revealed by molecular data.

Pentastomida are lung parasites of a variety of hosts, mainly reptiles. Raillietiella is the genus with the largest number of species, whose taxonomic identification is still largely based on morphological data alone. In this classification, differences divide the genus into morphotypic groups. The Raillietiella parasites of insectivorous lizards, for example, are divided into "Group I" with species with hooks with sharp tips and "Group II" with posterior hooks with blunt tips. In the present work, we used molecular analysis to infer the morphological variation in hooks and size of specimens of Raillietiella mottae, parasites of several species of insectivorous lizards. Our results demonstrate that morphological differences comprise a phenotypic plasticity of a single species, whose variation is associated with host species, with females being larger and with hooks with blunt tips in nocturnal geckos and smaller ones with sharp tips in diurnal insectivorous lizards of different species, sizes, and habitats.

A host driven parasitoid syndrome: Convergent evolution of multiple traits associated with woodboring hosts in Ichneumonidae (Hymenoptera, Ichneumonoidea).

The evolution of convergent phenotypes is of major interest in biology because of their omnipresence and ability to inform the study of evolutionary novelty and constraint. Convergent phenotypes can be combinations of traits that evolve concertedly, called syndromes, and these can be shaped by a common environmental pressure. Parasitoid wasps which use a wide variety of arthropod hosts have also repeatedly and convergently switched host use across their evolutionary history. They thus represent a natural laboratory for the evolution of trait syndromes that are associated with parasitism of specific hosts and host substrates. In this study, we tested the evolution of co-evolving characters in the highly diverse family Ichneumonidae associated with ovipositing in a specific and well-defined substrate: wood. Using a newly constructed phylogeny and an existing morphological dataset, we identified six traits correlated with the wood-boring lifestyle that demonstrate convergent evolution. At least one trait, the presence of teeth on the ovipositor, typically preceded the evolution of other traits and possibly the switch to parasitism of wood-boring hosts. For each trait, we provide a historical review of their associations with wood-boring parasitoids, reevaluate the function of some characters, and suggest future coding improvements. Overall, we demonstrate the convergent evolution of multiple traits associated with parasitism of woodboring hosts and propose a syndrome in a hyper diverse lineage of parasitoid wasps.

First report of Eupterote sp. nr. gardneri Byrk, 1950 (Lepidoptera: Eupterotidae) as a defoliator pest of banana in Kerala, India with notes on its biology

In this study, Eupterote sp. nr. gardneri Byrk, 1950 (=Eupterote geminata (Walker) ssp. gardneri Byrk, 1950) is recorded for the first time as a pest of banana in India. The outbreaks and crop damage caused by the hairy caterpillars of this species are documented with illustrated images. The banana cultivars Palayamkodan, Nendran, and Ney Poovan in the field, as well as cv. Popoulu in insect net house studies, were identified as preferred host varieties. Detailed morphological characteristics of the final instar caterpillar and adults, along with photographic illustrations, are provided. The biology of the pest and additional host plant records from Kerala are also discussed. Key words: First report of Eupterote sp, Eupterotidae, pest, defoliator, banana, economic loss, biology, host plants, India.

Application and antagonistic mechanisms of atoxigenic Aspergillus strains for the management of fungal plant diseases.

This review covers, for the first time, all methods based on the use of Aspergillus strains as biocontrol agents for the management of plant diseases caused by fungi and oomycetes. Atoxigenic Aspergillus strains have been screened in a variety of hosts, such as peanuts, maize kernels, and legumes, during the preharvest and postharvest stages. These strains have been screened against a wide range of pathogens, such as Fusarium, Phytophthora, and Pythium species, suggesting a broad applicability spectrum. The highest efficacies were generally observed when using non-toxigenic Aspergillus strains for the management of mycotoxin-producing Aspergillus strains. The modes of action included the synthesis of antifungal metabolites, such as kojic acid and volatile organic compounds (VOCs), secretion of hydrolytic enzymes, competition for space and nutrients, and induction of disease resistance. Aspergillus strains degraded Sclerotinia sclerotiorum sclerotia, showing high control efficacy against this pathogen. Collectively, although two Aspergillus strains have been commercialized for aflatoxin degradation, a new application of Aspergillus strains is emerging and needs to be optimized.

Cryptosporidium spp. in German wildlife: Detection, regional occurrence and diversity in wild boar, roe, red and fallow deer

Cryptosporidium is a cause of diarrheal infections responsible for a loss of human and animal welfare worldwide. The impact of the parasite is underestimated and the reported sources of infection are diverse, as it occurs in a wide variety of hosts. Wildlife has been reported as a notifiable source, but few studies are available on its occurrence in European wild boar and cervid species. To determine the occurrence of Cryptosporidium in game in Brandenburg, Germany, a molecular survey was conducted during the 2017 to 2020 hunting seasons. A total of 562 fecal samples from wild boar (Sus scrofa, n = 262), roe deer (Capreolus capreolus, n = 174), red deer (Cervus elaphus, n = 62), fallow deer (Dama dama, n = 51) and 13 samples of unspecified species were analyzed for both 18S ribosomal RNA (18S rRNA) and Cryptosporidium oocyst wall protein (COWP) gene sequence regions. PCR results showed that 21.2 % of the samples (n = 119/562) were positive for at least one target gene (18S rRNA: n = 114; COWP: n = 14), but differences in Cryptosporidium occurrence were observed within species and hunting seasons, with variations ranging from 1.8 % to 41.7 % (roe deer), respectively. Analysis of Sanger sequences of the 18S rRNA and COWP PCR products indicated that the C. sp. deer genotype was predominant in deer (roe deer: 86.7 %, red deer: 66.7 %, fallow deer: 58.8 %), while C. suis and C. scrofarum were mainly detected in wild boar (88.5 %). The human pathogenic species C. parvum was detected in only 1.2 % (n = 7) of the samples analyzed, but without a clear indication of a specific wild animal host. The highest Cryptosporidium diversity was found in wild boar and roe deer with five and four different species, respectively. Comparison of the 18S rRNA sequences with the designated reference revealed minor variations at several nucleotide positions in some isolates, possibly indicating evolutionary adaptations and the development of new subtypes. In conclusion, wildlife represents a reservoir for a diverse spectrum of Cryptosporidium species and may thus contribute to their environmental spread and the transmission to humans.

Metarhiziumpuerense (Hypocreales, Clavicipitaceae): a new species from Yunnan, south-western China.

As a genus within the Clavicipitaceae, Metarhizium exhibits rich morphological and ecological diversity, with a wide distribution and a variety of hosts. Currently, sixty-eight species of Metarhizium have been described. A new species of Metarhizium, M.puerense (Hong Yu bis), was described in Pu'er City, Yunnan Province, south-western China. Based on morphological characteristics and multilocus phylogenetic analyses, Metarhiziumpuerense was confirmed to be phylogenetically related to M.album, but was clearly separated and formed a distinct branch. In contrast, the host of Metarhiziumalbum was plants and leafhoppers and that lepidopteran larvae were the host of M.puerense. The diagnostic features of M.puerense were solitary to multiple stromata and smooth-walled, cylindrical with rounded apices conidia.

The fate of antibiotics and antibiotic resistance genes in Large-Scale chicken farm Environments: Preliminary view of the performance of National veterinary Antimicrobial use reduction Action in Guangdong, China

In 2018, China implemented the Veterinary Antimicrobial Use Reduction Action to curb the rapid development of antibiotic resistance (AR). However, the AR-related pollutions in animal farms after the reduction policy has been poorly investigated. Here, we performed a comprehensive investigation combining UPLC-MS/MS, metagenomic, and bacterial genomic analyses in eight representative large-scale chicken farms in Guangdong, China. Our results showed that antibiotics and ARGs contaminations were more severe in broiler farms than in layer farms. Notably, diverse tet(X) variants were prevalent in the chicken farms. These tet(X)s was carried by diverse E. coli lineages and obviously correlated with ISCR2 and IS1B transposases. The resistomes in chicken farms was significantly correlated with microbial community, and multiple factor analyses indicated that the joint effect of antibiotics-microbial community-MGEs was the most dominant driver of ARGs. Host tracking identified a variety of ARG bacterial hosts and the co-occurrence of ARGs-MRGs-MGEs. Source tracking indicated that the inherent component represented the main feature of resistomes in different hosts, while ARG transfer between the chicken gut and farm environments were frequent. A multiperspective evaluation of AR risk revealed that the early effect of antibiotic reduction was exhibited by the mitigation of maximum level of risky ARGs, prevalence of environmental AR pathogens, and HGT potential of ARGs mediated by phage structures. Overall, our findings provide insights into the antibiotic and ARG profiles in large-scale chicken farms with different rearing strategies and demonstrate a preliminary view of the performance of antibiotic reduction actions in China.

Serving with a Smile on Airbnb: Analyzing the Economic Returns and Behavioral Underpinnings of the Host’s Smile

Abstract Non-informational cues, such as facial expressions, can significantly influence judgments and interpersonal impressions. While past research has explored how smiling affects business outcomes in offline or in-store contexts, relatively less is known about how smiling influences consumer choice in e-commerce settings even when there is no face-to-face interaction. In this paper, we use a longitudinal Airbnb dataset and a facial attribute classifier to quantify the effect of a smile in the host’s profile photo on property demand and identify factors that influence when a host smile is likely to have the biggest effect. A smile in the host’s profile photo increases property demand by 3.5% on average. This effect is moderated by a variety of host and property characteristics that provide evidence for the role of uncertainty underlying why smiling increases demand. Specifically, when there is greater uncertainty regarding either the quality of the accommodations or the interaction with the host, a host smile will have a greater effect on demand. Online experiments confirm this pattern, offering further support for uncertainty perceptions driving the effect of smiling on increased Airbnb demand, and show that the effect of smiling on demand generalizes beyond Airbnb.

The neonatal Fc receptor (FcRn) is a pan-arterivirus receptor

Arteriviruses infect a variety of mammalian hosts, but the receptors used by these viruses to enter cells are poorly understood. We identified the neonatal Fc receptor (FcRn) as an important pro-viral host factor via comparative genome-wide CRISPR-knockout screens with multiple arteriviruses. Using a panel of cell lines and divergent arteriviruses, we demonstrate that FcRn is required for the entry step of arterivirus infection and serves as a molecular barrier to arterivirus cross-species infection. We also show that FcRn synergizes with another known arterivirus entry factor, CD163, to mediate arterivirus entry. Overexpression of FcRn and CD163 sensitizes non-permissive cells to infection and enables the culture of fastidious arteriviruses. Treatment of multiple cell lines with a pre-clinical anti-FcRn monoclonal antibody blocked infection and rescued cells from arterivirus-induced death. Altogether, this study identifies FcRn as a novel pan-arterivirus receptor, with implications for arterivirus emergence, cross-species infection, and host-directed pan-arterivirus countermeasure development.

Survey of gastrointestinal coccidian parasites of pet birds in Tehran

ABSTRACT Birds of various families and genera comprise a notable proportion of veterinary clients in veterinary practice. Regarding the scarcity of information on avian coccidia in pet birds, this study was designed to investigate and identify the diversity of gastrointestinal coccidian protozoa in caged pet birds. Accordingly, droppings samples were collected in 2.5% potassium dichromate and examined for the presence of oocysts by wet smear and by flotation with the saturated salt solution. Detected oocysts were further morphologically specified. Special Modified Ziehl-Neelsen stain was used for the detection of Cryptosporidium spp. oocysts. Out of the 145 droppings that were collected for parasitological investigations, it was discovered that a Japanese quail (Coturnix japonica) had a Cryptosporidium sp. infection (1/145: 0.7%). Additionally, Isospora spp. was found in a common mynah and a canary (2/145: 1.4%), while Eimeria sp. was detected in a canary (1/145: 0.7%). Studied birds were clinically normal and no signs of intestinal infection were observed. The oocysts are described morphologically in detail and compared with the available data. Periodic faecal examination should be recommended for monitoring intestinal parasites in pet birds both from a public health perspective for Cryptosporidium and for avian host health in the case of non-zoonotic parasites. Additionally, the identification of parasite/host species composition will enhance our understanding of species diversity and the variety of hosts that coccidian parasites are capable of infecting.

Prediction of resistance, virulence, and host-by-pathogen interactions using dual-genome prediction models

Key messageIntegrating disease screening data and genomic data for host and pathogen populations into prediction models provides breeders and pathologists with a unified framework to develop disease resistance.Developing disease resistance in crops typically consists of exposing breeding populations to a virulent strain of the pathogen that is causing disease. While including a diverse set of pathogens in the experiments would be desirable for developing broad and durable disease resistance, it is logistically complex and uncommon, and limits our capacity to implement dual (host-by-pathogen)-genome prediction models. Data from an alternative disease screening system that challenges a diverse sweet corn population with a diverse set of pathogen isolates are provided to demonstrate the changes in genetic parameter estimates that result from using genomic data to provide connectivity across sparsely tested experimental treatments. An inflation in genetic variance estimates was observed when among isolate relatedness estimates were included in prediction models, which was moderated when host-by-pathogen interaction effects were incorporated into models. The complete model that included genomic similarity matrices for host, pathogen, and interaction effects indicated that the proportion of phenotypic variation in lesion size that is attributable to host, pathogen, and interaction effects was similar. Estimates of the stability of lesion size predictions for host varieties inoculated with different isolates and the stability of isolates used to inoculate different hosts were also similar. In this pathosystem, genetic parameter estimates indicate that host, pathogen, and host-by-pathogen interaction predictions may be used to identify crop varieties that are resistant to specific virulence mechanisms and to guide the deployment of these sources of resistance into pathogen populations where they will be more effective.

Small non-coding satellite RNAs - the 'game changers' at the virus-host plant interaction?

Satellite RNAs (satRNAs) are RNA molecules associated with many plant viruses and fully dependent on them for replication, encapsidation, and movement within the plant or transmission from plant to plant. Their classification is based on their length, functional protein-coding capacity, and RNA structure (whether linear or circular). They have been of interest for a long time as some of them, in particular systems, cause significant changes in the pathogenesis and epidemiology of plant viruses. The outcomes of how satRNAs affect pathogenesis depend on the components of the pathosystem: host plant species or variety, virus species or even strain, and the sequence of satRNA. These can be additionally affected by biotic and abiotic factors, for example, environmental conditions such as the presence of their vectors or ambient temperature. satRNAs may interfere with primary metabolism, signalling, plant defence [including post-transcriptional gene silencing (PTGS)], as well as the efficiency of virus transmission from plant to plant. In recent years, due to wider access to high-throughput technologies and the extension of studies on satRNAs to include the involvement of external factors in plant-virus-satRNA systems, we are gaining a broader view of the consequences of the presence of these small molecules in viral infections. This review presents the state of the art of satRNA interactions with the helper virus and host plant as well as the influence of satRNAs on the insect vector's behaviour. Moreover, areas requiring further research are identified and knowledge gaps indicated.