scholarly journals Prevalence and genetic variability of tick-borne encephalitis virus in host-seeking Ixodes ricinus in northern Italy

2009 ◽  
Vol 90 (12) ◽  
pp. 2877-2883 ◽  
Author(s):  
Giovanna Carpi ◽  
Luigi Bertolotti ◽  
Sergio Rosati ◽  
Annapaola Rizzoli
Keyword(s):  
Genetic Variability ◽  
Ixodes Ricinus ◽  
Evolutionary Dynamics ◽  
Phylogenetic Analyses ◽  
Northern Italy ◽  
Nucleotide Sequence Analysis ◽  
Envelope Gene ◽  
North East ◽  
Tick Borne Encephalitis ◽  
Pcr Targeting

Tick-borne encephalitis (TBE) is a severe disease that has been endemic in north-east Italy since 1992. Over the past two decades, there has been an increase in the number of human cases reported in many European countries, including Italy. To assess the current TBE infection risk, questing ticks were collected from known TBE foci, as well as from a site in northern Italy where no human infections have been reported previously. A total of 1739 Ixodes ricinus (1485 nymphs and 254 adults) was collected and analysed for TBEV prevalence by a real-time RT-PCR targeting the 3′ untranslated region. Phylogenetic analyses of the partial envelope gene were conducted on two newly sequenced TBE virus (TBEV) strains and 28 previously published sequences to investigate the genealogical relationships of the circulating TBEV strains. These phylogenetic analyses confirmed a previous report that the European TBEV subtype is the only subtype circulating within the TBE foci in north-east Italy. Interestingly, nucleotide sequence analysis revealed a high degree of divergence (mean 2.54 %) between the TBEV strains recovered in the Italian province of Trento, despite the circulation of a single TBEV subtype. This elevated genetic variability within a single TBE focus may reflect local differences in the long-standing evolutionary dynamics of TBEV at this site relative to previously characterized sites, or more recent and continuous reintroduction of various TBEV strains.

Effect of host populations on the intensity of ticks and the prevalence of tick-borne pathogens: how to interpret the results of deer exclosure experiments

Parasitology ◽  
2008 ◽  
Vol 135 (13) ◽  
pp. 1531-1544 ◽  
Author(s):  
A. PUGLIESE ◽  
R. ROSÀ
Keyword(s):  
Ixodes Ricinus ◽  
Dynamic Models ◽  
Infection Risk ◽  
Northern Italy ◽  
Pathogen Transmission ◽  
Infection Prevalence ◽  
Tick Density ◽  
Dead End ◽  
Tick Borne Encephalitis ◽  
Experimental Plots

SUMMARYDeer are important blood hosts for feeding Ixodes ricinus ticks but they do not support transmission of many tick-borne pathogens, so acting as dead-end transmission hosts. Mathematical models show their role as tick amplifiers, but also suggest that they dilute pathogen transmission, thus reducing infection prevalence. Empirical evidence for this is conflicting: experimental plots with deer removal (i.e. deer exclosures) show that the effect depends on the size of the exclosure. Here we present simulations of dynamic models that take into account different tick stages, and several host species (e.g. rodents) that may move to and from deer exclosures; models were calibrated with respect to Ixodes ricinus ticks and tick-borne encephalitis (TBE) in Trentino (northern Italy). Results show that in small exclosures, the density of rodent-feeding ticks may be higher inside than outside, whereas in large exclosures, a reduction of such tick density may be reached. Similarly, TBE prevalence in rodents decreases in large exclosures and may be slightly higher in small exclosures than outside them. The density of infected questing nymphs inside small exclosures can be much higher, in our numerical example almost twice as large as that outside, leading to potential TBE infection risk hotspots.

scholarly journals MASKED GENOTYPE 6 OF BOVINE LEUKEMIA VIRUS IS FOUND IN COLOMBIAN CATTLE

2019 ◽  
Author(s):  
Adriana Patricia Corredor-Figueroa ◽  
Nury Nathalia Olaya-Galán ◽  
Sandra Patricia Salas ◽  
Juan Sebastián Quintero ◽  
Álvaro Fajardo ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Bovine Leukemia Virus ◽  
Phylogenetic Analyses ◽  
Leukemia Virus ◽  
Gene Analysis ◽  
Economic Losses ◽  
Envelope Gene ◽  
Genotype 1 ◽  
Global Epidemiology ◽  
Bovine Leukosis

Abstract Background Viral diseases such as bovine leukosis are a major cause of health problems associated with economic losses in the livestock industry worldwide. The prevalence of bovine leukosis ranges between 4% and 90%, and this disease is considered endemic. The etiological agent is bovine leukemia virus (BLV). Ten BLV genotypes have been reported based on analysis of complete or partial envelope gene sequences, of which genotype 1 is the most prevalent. However, the genetic variability of BLV variants circulating in Colombia remains unexplored. Therefore, in the present study, we analyzed blood samples collected from 289 cows distributed in 75 farms across the country. PCR amplification of env, gag and tax gene segments was performed. The obtained amplicons were sequenced and then subjected to phylogenetic analyses. Results A total of 62% of the cows present at 92% of the farms were BLV-positive. Genotype 1 was exclusively detected by env and gag gene segments when analyzed using previously reported primers. However, tax gene analysis revealed circulation of genotype 6 variants, which were also detected based on env gene analysis with newly designed primers. These results indicate that current genotyping approaches based on partial env sequencing may bias BLV genetic variability approaches and underestimate the diversity of the detected BLV genotypes. Conclusions This report is the first molecular and epidemiological study of BLV conducted in Colombia and contributes to the global epidemiology of the virus; it also reinforces the great impact of BLV on the country’s livestock and thus is a useful resource for farmers and government entities.

scholarly journals A27 Whole genome characterization of influenza D viruses detected in cattle herds in northern Italy between 2015 and 2017

2019 ◽  
Vol 5 (Supplement_1) ◽  
Author(s):  
A Bianco ◽  
L Cavicchio ◽  
A Fusaro ◽  
G Rizzo ◽  
A Milani ◽  
...  
Keyword(s):  
Host Range ◽  
Phylogenetic Analyses ◽  
Illumina Miseq ◽  
Northern Italy ◽  
Influenza Viruses ◽  
Broad Host Range ◽  
Human Influenza ◽  
Cattle Herds ◽  
Pcr Targeting

Abstract Influenza D virus (IDV) is a new viral genus identified within the Orthomyxoviridae family, showing 50 per cent amino acid identity with human influenza C virus. Similar to human influenza viruses of the C genus, IDV also harbors 7 genomic segments and uses 9-O-acetylated sialic acids as cell receptors. This newly emerged virus exhibits a broad host range and is capable of infecting swine, cattle, sheep, goats, ferrets, and guinea pigs. In Italy, IDV was first detected in archived samples collected between 2014 and 2015 from cattle and swine in the Po Valley area. Here, we report the genetic characterization of IDV viruses detected in an extensive area of northern Italy, namely Veneto, Lombardy, and Piedmont, through passive surveillance between September 2015 and October 2017. A total of 482 samples, including nasal swabs, lungs, and bronchoalveolar lavage fluid, collected from 309 cattle farms were tested. Thirty cattle herds turned out to be positive, for a total of 40 samples positive by Real Time RT-PCR targeting the PB2 gene. Representative IDV positive swabs were sequenced on an Illumina Miseq platform, and phylogenetic analyses were performed for each genome segment. The analyses of the seven gene segments demonstrated that the viruses identified in the north of Italy clearly grouped within a genetic cluster of IDV sequences previously described in Italy and in the USA, thus suggesting a common origin for these viruses. Interestingly, the IDVs identified in Italy presented a low similarity (96.1% to 98.8% for the seven gene segments) to the French IDVs, which is the only other European country where this pathogen has been identified and characterized so far. The wide IDV host range and the ability of this virus to reassort are a matter of concern. Results of this study indicate that IDV is extensively circulating among bovine herds in Northern Italy and suggest a potential role of IDV in the bovine respiratory disease complex, highlighting the need to perform surveillance on an ongoing basis to track its spread and evolution.

scholarly journals Population Dynamics in Italian Canids between the Late Pleistocene and Bronze Age

Genes ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1409
Author(s):  
Kyriaki Koupadi ◽  
Francesco Fontani ◽  
Marta Maria Ciucani ◽  
Elena Maini ◽  
Sara De Fanti ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Bronze Age ◽  
Late Pleistocene ◽  
Close Relationships ◽  
Phylogenetic Analyses ◽  
Hypervariable Region ◽  
Northern Italy ◽  
European Regions ◽  
Hypervariable Region 1 ◽  
Dog Domestication

Dog domestication is still largely unresolved due to time-gaps in the sampling of regions. Ancient Italian canids are particularly understudied, currently represented by only a few specimens. In the present study, we sampled 27 canid remains from Northern Italy dated between the Late Pleistocene and Bronze Age to assess their genetic variability, and thus add context to dog domestication dynamics. They were targeted at four DNA fragments of the hypervariable region 1 of mitochondrial DNA. A total of 11 samples had good DNA preservation and were used for phylogenetic analyses. The dog samples were assigned to dog haplogroups A, C and D, and a Late Pleistocene wolf was set into wolf haplogroup 2. We present our data in the landscape of ancient and modern dog genetic variability, with a particular focus on the ancient Italian samples published thus far. Our results suggest there is high genetic variability within ancient Italian canids, where close relationships were evident between both a ~24,700 years old Italian canid, and Iberian and Bulgarian ancient dogs. These findings emphasize that disentangling dog domestication dynamics benefits from the analysis of specimens from Southern European regions.

scholarly journals Diversity of the population of Tick-borne encephalitis virus infecting Ixodes ricinus ticks in an endemic area of central Switzerland (Canton Bern)

2006 ◽  
Vol 87 (8) ◽  
pp. 2235-2241 ◽  
Author(s):  
Simona Casati ◽  
Lise Gern ◽  
Jean-Claude Piffaretti
Keyword(s):  
Ixodes Ricinus ◽  
Encephalitis Virus ◽  
Start Codon ◽  
Nucleotide Sequence Analysis ◽  
Natural Focus ◽  
Reading Frame ◽  
Tick Borne Encephalitis ◽  
Central Switzerland ◽  
Tick Borne Encephalitis Virus ◽  
Positive Strand Rna

Tick-borne encephalitis virus (TBEV), a member of the genus Flavivirus, has a positive-strand RNA genome containing a single open reading frame flanked by non-coding regions (NCRs). Ixodes ricinus ticks (n=307) were collected from vegetation in a natural TBEV focus in Belp, Switzerland. The presence and identity of the virus were determined by nested RT-PCR followed by sequencing of the 5′-terminal region that comprises the 5′ NCR and the capsid-encoding region (C). The presence of the western European TBEV subtype (W-TBEV) genome was detected in 14.3 % of the ticks. Nucleotide sequence analysis revealed a high variability of 55.5 %. In particular, four DNA fragments (CS ‘A’, CS ‘B’, the folding-stem structure and the start codon) showed substantial heterogeneity, which has the potential of compromising replication, translation and packaging of the viral genome. This variability may reflect a viral strategy to select the fittest RNA molecule to produce a viral infection in the different vertebrate hosts that may be encountered by the ticks. It may also indicate a possible ancient introduction of TBEV to the Belp site. In addition, it may contribute to explaining the annual low incidence of tick-borne encephalitis in the natural focus of Belp, despite the high prevalence of TBEV genomes in ticks.

TBE in Italy

2019 ◽  
Author(s):  
Valentina Tagliapietra ◽  
Flavia Riccardo ◽  
Giovanni Rezza
Keyword(s):  
Case Series ◽  
East Part ◽  
Mountainous Regions ◽  
North East ◽  
The North ◽  
Tick Borne Encephalitis ◽  
Low Incidence

Italy is considered a low incidence country for tick-borne encephalitis (TBE) in Europe. Areas at higher risk for TBE in Italy are geographically clustered in the forested and mountainous regions and provinces in the north east part of the country, as suggested by TBE case series published over the last decade.

TBE in Italy

2020 ◽  
Keyword(s):  
Surveillance System ◽  
Ad Hoc ◽  
National Level ◽  
Case Series ◽  
Incidence Rates ◽  
Mountainous Regions ◽  
North East ◽  
The North ◽  
Tick Borne Encephalitis ◽  
Low Incidence

Italy is considered a low-incidence country for tick-borne encephalitis (TBE) in Europe.1 Areas at higher risk for TBE in Italy are geographically clustered in the forested and mountainous regions and provinces in the north east part of the country, as suggested by TBE case series published over the last decade.2-5 A national enhanced surveillance system for TBE has been established since 2017.6 Before this, information on the occurrence of TBE cases at the national level in Italy was lacking. Both incidence rates and the geographical distribution of the disease were mostly inferred from endemic areas where surveillance was already in place, ad hoc studies and international literature.1

scholarly journals Long-Term Cocirculation of Two Strains of Pepino Mosaic Virus in Tomato Crops and Its Effect on Population Genetic Variability

2020 ◽  
Vol 110 (1) ◽  
pp. 49-57 ◽  
Author(s):  
C. Alcaide ◽  
M. P. Rabadán ◽  
M. Juárez ◽  
P. Gómez
Keyword(s):  
Genetic Variability ◽  
Mosaic Virus ◽  
Evolutionary Dynamics ◽  
Geographical Area ◽  
Viral Fitness ◽  
Mixed Infections ◽  
Supporting Evidence ◽  
Pepino Mosaic Virus ◽  
Nucleotide Variability

Mixed viral infections are common in plants, and the evolutionary dynamics of viral populations may differ depending on whether the infection is caused by single or multiple viral strains. However, comparative studies of single and mixed infections using viral populations in comparable agricultural and geographical locations are lacking. Here, we monitored the occurrence of pepino mosaic virus (PepMV) in tomato crops in two major tomato-producing areas in Murcia (southeastern Spain), supporting evidence showing that PepMV disease-affected plants had single infections of the Chilean 2 (CH2) strain in one area and the other area exhibited long-term (13 years) coexistence of the CH2 and European (EU) strains. We hypothesized that circulating strains of PepMV might be modulating the differentiation between them and shaping the evolutionary dynamics of PepMV populations. Our phylogenetic analysis of 106 CH2 isolates randomly selected from both areas showed a remarkable divergence between the CH2 isolates, with increased nucleotide variability in the geographical area where both strains cocirculate. Furthermore, the potential virus–virus interaction was studied further by constructing six full-length infectious CH2 clones from both areas, and assessing their viral fitness in the presence and absence of an EU-type isolate. All CH2 clones showed decreased fitness in mixed infections and although complete genome sequencing indicated a nucleotide divergence of those CH2 clones by area, the magnitude of the fitness response was irrespective of the CH2 origin. Overall, these results suggest that although agroecological cropping practices may be particularly important for explaining the evolutionary dynamics of PepMV in tomato crops, the cocirculation of both strains may have implications on the genetic variability of PepMV populations.

scholarly journals Molecular Identification of Trypanosoma evansi Isolated from Arabian Camels (Camelus dromedarius) in Riyadh and Al-Qassim, Saudi Arabia

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1149
Author(s):  
Dina M. Metwally ◽  
Isra M. Al-Turaiki ◽  
Najwa Altwaijry ◽  
Samia Q. Alghamdi ◽  
Abdullah D. Alanazi
Keyword(s):  
Saudi Arabia ◽  
Infection Rate ◽  
Ribosomal Rna ◽  
Phylogenetic Analyses ◽  
Trypanosoma Evansi ◽  
Camelus Dromedarius ◽  
18S Ribosomal Rna ◽  
18S Ribosomal Rna Gene ◽  
Polymerase Chain ◽  
Pcr Targeting

We analyzed the blood from 400 one-humped camels, Camelus dromedarius (C. dromedarius), in Riyadh and Al-Qassim, Saudi Arabia to determine if they were infected with the parasite Trypanosoma spp. Polymerase chain reaction (PCR) targeting the internal transcribed spacer 1 (ITS1) gene was used to detect the prevalence of Trypanosoma spp. in the camels. Trypanosoma evansi (T. evansi) was detected in 79 of 200 camels in Riyadh, an infection rate of 39.5%, and in 92 of 200 camels in Al-Qassim, an infection rate of 46%. Sequence and phylogenetic analyses revealed that the isolated T. evansi was closely related to the T. evansi that was detected in C. dromedarius in Egypt and the T. evansi strain B15.1 18S ribosomal RNA gene identified from buffalo in Thailand. A BLAST search revealed that the sequences are also similar to those of T. evansi from beef cattle in Thailand and to T. brucei B8/18 18S ribosomal RNA from pigs in Nigeria.

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