Long-Term Effects of Climate and Litter Chemistry on Rates and Stable Fractions of Decomposing Scots Pine and Norway Spruce Needle Litter—A Synthesis

We have reviewed information on early-, late- and limit-value decomposition stages for litter of Norway spruce (Picea abies) and Scots pine (Pinus silvestris). This synthesis covers c 16 studies/papers made along a climatic gradient; range in mean annual temperature (MAT) from −1 to +7 °C and mean annual precipitation (MAP) from 425 to 1070 mm. Scots pine has an early stage dominated by carbohydrate decomposition and a late stage dominated by decomposition of lignin; Norway spruce has just one stage dominated by lignin decomposition. We used data for annual mass loss to identify rate-regulating factors in both stages; climate data, namely, MAT and MAP, as well as substrate properties, namely, nitrogen (N), acid unhydrolyzable residue (AUR), manganese (Mn). Early-stage decomposition for Scots pine litter was dominated positively by MAT; the late stage was dominated negatively by MAT, N, and AUR, changing with decomposition stage; there was no effect of Mn. Norway spruce litter had no early stage; decomposition in the lignin-dominated stage was mainly negative to MAP, a negative relationship to AUR and non-significant relationships to N and MAT. Mn had a positive relationship. Limit values for decomposition, namely, the accumulated mass loss at which decomposition is calculated to be zero, were related positively to Mn and AUR for Scots pine litter and negatively to AUR for Norway spruce litter. With different sets of rate-regulating factors as well as different compounds/elements related to the limit values, the decomposition patterns or pathways are different

Long-Term Effects of Climate and Litter Chemistry on Rates and Stable Fractions of Decomposing Scots Pine and Norway Spruce Needle Litter—A Synthesis

We have reviewed information on early-, late- and limit-value decomposition stages for litter of Norway spruce (Picea abies) and Scots pine (Pinus silvestris). This synthesis covers c 16 studies/papers made along a climatic gradient; range in mean annual temperature (MAT) from −1 to +7 °C and mean annual precipitation (MAP) from 425 to 1070 mm. Scots pine has an early stage dominated by carbohydrate decomposition and a late stage dominated by decomposition of lignin; Norway spruce has just one stage dominated by lignin decomposition. We used data for annual mass loss to identify rate-regulating factors in both stages; climate data, namely, MAT and MAP, as well as substrate properties, namely, nitrogen (N), acid unhydrolyzable residue (AUR), manganese (Mn). Early-stage decomposition for Scots pine litter was dominated positively by MAT; the late stage was dominated negatively by MAT, N, and AUR, changing with decomposition stage; there was no effect of Mn. Norway spruce litter had no early stage; decomposition in the lignin-dominated stage was mainly negative to MAP, a negative relationship to AUR and non-significant relationships to N and MAT. Mn had a positive relationship. Limit values for decomposition, namely, the accumulated mass loss at which decomposition is calculated to be zero, were related positively to Mn and AUR for Scots pine litter and negatively to AUR for Norway spruce litter. With different sets of rate-regulating factors as well as different compounds/elements related to the limit values, the decomposition patterns or pathways are different

Divergent strains of EHV-1 in Swedish outbreaks during 2012 to 2021

Equid alphaherpesvirus 1 (EHV-1) is a ubiquitous and significant viral pathogen in horses worldwide, causing a range of conditions, including fever, respiratory disease, abortion in pregnant mares and the severe neurological disease called equine herpes myeloencephalopathy (EHM). Despite that EHV-1 is a notifiable animal disease in Sweden, there is limited knowledge about the circulating strains. This study aimed to analyze the genetic diversity of EHV-1 strains in equine samples from different Swedish outbreaks by partial genome sequencing. Genotyping based on three selected open reading frames ORF11, ORF30, and ORF34 in the viral genome was conducted for 55 outbreaks of EHV-1 spanning from the years 2012 to 2021. The analysis revealed 14 different genovariants, with one prominent genovariant identified in 49% of the outbreaks. Additionally, the study identified seven mutations not previously described. Three new mutations were demonstrated in ORF11, all synonymous, and four new mutations in ORF34, two synonymous, and two non-synonymous. Notably, different EHV-1 genovariants were found in five out of six studied EHM outbreaks, but clonal spreading was shown within the outbreaks. Moreover, the study demonstrated that healthy (recovered) horses that returned from an EHM outbreak at an international meeting in Valencia, Spain (2021), were positive for the virus clone responsible for the severe disease outbreak despite several weeks of quarantine. These findings shed light on the genetic diversity and transmission dynamics of the virus and significantly contribute to better understanding of the epidemiology of EHV-1 in Sweden and globally

A case report of serological evidence of paramyxoviruses related to Porcine orthorubulavirus in Mexican bats

In this report, we showed the presence of antibodies to Porcine orthorubulavirus (PRV) in Mexican bats using a serological approach. A total of 42 bats, belonging to seven different species, were sampled from two different refuges/caves, located near to a pig fattening area where spontaneous outbreaks of PRV had occurred. Analysis by serum-virus neutralizing and immunoperoxidase monolayer assay revealed the presence of antibodies in fifteen out of 42 investigated bats (i.e. 35%), six of them were also positive by Paramyxoviridae family using PCR assay targeting the L gene of paramyxoviruses. This case demonstrates for the first time antibodies detection of this virus in different bats species which is important for our understanding of PRV ecology, evolution and mechanism of cross-species transmission. These findings support the hypothesis that bats could act as an intermediate or natural host for interspecies transmission of certain paramyxoviruses

Molecular Diversity of Hard Tick Species from Selected Areas of a Wildlife-Livestock Interface Ecosystem at Mikumi National Park, Morogoro Region, Tanzania

Ticks are one of the most important arthropod vectors and reservoirs as they harbor a wide variety of viruses, bacteria, fungi, protozoa, and nematodes, which can cause diseases in human and livestock. Due to their impact on human, livestock, and wild animal health, increased knowledge of ticks is needed. So far, the published data on the molecular diversity between hard ticks species collected in Tanzania is scarce. The objective of this study was to determine the genetic diversity between hard tick species collected in the wildlife-livestock interface ecosystem at Mikumi National Park, Tanzania using the mitochondrion 16S rRNA gene sequences. Adult ticks were collected from cattle (632 ticks), goats (187 ticks), and environment (28 ticks) in the wards which lie at the border of Mikumi National Park. Morphological identification of ticks was performed to genus level. To identify ticks to species level, molecular analysis based on mitochondrion 16S rRNA gene was performed. Ticks representing the two genera (Hyalomma and Rhipicephalus) were identified using morphological characters. Six species were confirmed based on mitochondrion 16S rRNA gene, including Rhipicephalus microplus, Rhipicephalus evertsi, Hyalomma rufipes, Hyalomma truncatum, Hyalomma marginatum, and Hhyalomma turanicum. The presence of different clusters of tick species reflects the possible biological diversity of the hard ticks present in the study region. Further studies are however required to quantify species of hard ticks present in the study region and the country in general over a larger scale

Diversity of viruses in hard ticks (Ixodidae) from select areas of a wildlife-livestock interface ecosystem at Mikumi National Park, Tanzania

Many of the recent emerging infectious diseases have occurred due to the transmission of the viruses that have wildlife reservoirs. Arthropods, such as ticks, are known to be important vectors for spreading viruses and other pathogens from wildlife to domestic animals and humans. In the present study, we explored the diversity of viruses in hard ticks (Ixodidae) from select areas of a wildlife-livestock interface ecosystem at Mikumi National Park, Tanzania using a metagenomic approach. cDNA and DNA were amplified with random amplification and Illumina high-throughput sequencing was performed. The high-throughput sequenced data was imported to the CLC genomic workbench and trimmed based on quality (Q = 20) and length (≥ 50). The trimmed reads were assembled and annotated through Blastx using Diamond against the National Center for Biotechnology Information non-redundant database and its viral database. The MEGAN Community was used to analyze and to compare the taxonomy of the viral community. The obtained contigs and singletons were further subjected to alignment and mapping against reference sequences. The viral sequences identified were classified into bacteria, vertebrates, and invertebrates, plants, and protozoans viruses. Sequences related to known viral families; Retroviridae, Flaviviridae, Rhabdoviridae, Chuviridae, Orthomyxoviridae, Phenuiviridae, Totiviridae, Rhabdoviridae, Parvoviridae, Caulimoviridae, Mimiviridae and several Phages were reported. This result indicates that there are many viruses present in the study region, which we are not aware of and do not know the role they have or if they have the potential to spread to other species and cause diseases. Therefore, further studies are required to delineate the viral community present in the region over a large scale

Characterization of Pipistrellus pygmaeus Bat Virome from Sweden

Increasing amounts of data indicate that bats harbor a higher viral diversity relative to other mammalian orders, and they have been recognized as potential reservoirs for pathogenic viruses, such as the Hendra, Nipah, Marburg, and SARS-CoV viruses. Here, we present the first viral metagenomic analysis of Pipistrellus pygmaeus from Uppsala, Sweden. Total RNA was extracted from the saliva and feces of individual bats and analyzed using Illumina sequencing. The results identified sequences related to 51 different viral families, including vertebrate, invertebrate, and plant viruses. These viral families include Coronaviridae, Picornaviridae, Dicistroviridae, Astroviridae, Hepeviridae, Reoviridae, Botourmiaviridae, Lispviridae, Totiviridae, Botoumiaviridae, Parvoviridae, Retroviridae, Adenoviridae, and Partitiviridae, as well as different unclassified viruses. We further characterized three near full-length genome sequences of bat coronaviruses. A phylogenetic analysis showed that these belonged to alphacoronaviruses with the closest similarity (78–99% at the protein level) to Danish and Finnish bat coronaviruses detected in Pipistrellus and Myotis bats. In addition, the full-length and the near full-length genomes of picornavirus were characterized. These showed the closest similarity (88–94% at the protein level) to bat picornaviruses identified in Chinese bats. Altogether, the results of this study show that Swedish Pipistrellus bats harbor a great diversity of viruses, some of which are closely related to mammalian viruses. This study expands our knowledge on the bat population virome and improves our understanding of the evolution and transmission of viruses among bats and to other species

House crickets (Othroptera: Gryllidae: Acheta domesticus) reared in small-scale laboratory conditions harbour limited viral flora

Insects, such as crickets, are being used as a viable food source in many regions of the world, given their nutritional value for human and animal consumption. This study investigated the viral communities present in European house crickets and whether feed influences the composition of the crickets’ virome. The crickets were reared under environmentally controlled conditions and fed fresh red clover (fresh), red clover haylage (haylage), red clover hay (hay) or control feed. The viral metagenomic analysis of six replicates from each feed treatment showed that only a few reads were classified as viruses, mainly assigned to phages and insect-related viruses. A significant difference (PXinmoviridae, Polydnaviridae, Metaviridae, unclassified and ‘other’ viruses were also found in all the feed treatments. The results from this study may indicate that the feed for the crickets determines the richness of the viral flora of crickets, but overall, very few viral reads were identified, making it hard to draw any conclusion regarding the impact of the feed on viral richness