A 29 nucleotide deletion in open reading frame 8 (ORF8) is the most obvious genetic change in severe acute respiratory syndrome coronavirus (SARS-CoV) during its emergence in humans. In spite of ...intense study, it remains unclear whether the deletion actually reflects adaptation to humans. Here we engineered full, partially deleted (-29 nt), and fully deleted ORF8 into a SARS-CoV infectious cDNA clone, strain Frankfurt-1. Replication of the resulting viruses was compared in primate cell cultures as well as Rhinolophus bat cells made permissive for SARS-CoV replication by lentiviral transduction of the human angiotensin-converting enzyme 2 receptor. Cells from cotton rat, goat, and sheep provided control scenarios that represent host systems in which SARS-CoV is neither endemic nor epidemic. Independent of the cell system, the truncation of ORF8 (29 nt deletion) decreased replication up to 23-fold. The effect was independent of the type I interferon response. The 29 nt deletion in SARS-CoV is a deleterious mutation acquired along the initial human-to-human transmission chain. The resulting loss of fitness may be due to a founder effect, which has rarely been documented in processes of viral emergence. These results have important implications for the retrospective assessment of the threat posed by SARS.
Abstract
Background
Canine parvovirus (CPV) is one of the most important pathogens of dogs. Despite vaccination, CPV infections are still ubiquitous in dogs, and the three antigenic variants 2a, 2b ...and 2c are variously distributed in the canine population worldwide. To date, no information is available on CPV variants circulating in some European countries. The aim of this study was to genetically characterise the CPV detected in ten dogs with clinical signs of acute gastroenteritis in Romania. The presence of
Carnivore protoparvovirus
1 DNA was investigated in faecal samples using an end-point PCR targeting the complete VP2 gene and positive amplicons were sequenced and analysed.
Results
All ten dogs with acute gastroenteritis tested positive to
Carnivore protoparvovirus
1 DNA in faecal samples. The identified viruses belonged to CPV-2c type, showed identical sequences of the VP2 gene and were characterised by distinctive amino acid residues in the deduced VP2 protein: 5-glicine (5Gly), 267-tirosine (267Tyr), 324-isoleucine (324Ile) and 370-arginine (370Arg). These distinctive amino acid residues have already been reported in CPV-2c widespread in Asia and occasionally detected in Italy and Nigeria.
Conclusions
Since CPV-2c with VP2 amino acid residues 5Gly, 267Tyr, 324Ile and 370Arg were never reported before 2013, it can be assumed that this virus is progressively expanding its spread in the world dog population. This study adds new data about the presence of this new virus in Europe and underline worrying questions about its potential impact on the health of the canine population.
Canine parvovirus type 2 (CPV-2) is one of the most relevant pathogens associated with enteritis in dogs and is frequently reported in association with the detection of other pathogens in faeces. In ...this study the concomitant presence of Canine circovirus (CanineCV) and Canine adenovirus (CAdV) DNA in faecal or intestine samples of 95 dogs with parvovirus enteritis sampled in Italy (1995–2017) was investigated and the viruses identified were genetically characterised. Potential correlations with the antigenic variant of CPV-2 and with signalment data and outcome were evaluated. Twenty-eight of 95 (29.5%) CPV-2 infected dogs tested positive to other viruses: 7/28 were also positive to CanineCV, 1/28 to CAdV-1, 18/28 to CAdV-2, 1/28 to CanineCV and CAdV-2, and 1/28 to CAdV-1 and CAdV-2. The frequency of CAdV DNA detection and coinfections was significantly higher in purebred dogs compared to mixed breed ones (
P
= 0.002 and 0.009, respectively). The presence of coinfection was not associated with any other relevant data available, including CPV-2 variant and final outcome. The detection of CanineCV in a dog sampled in 2009 allowed to backdating its circulation in dogs. The eight CanineCV completely sequenced were phylogenetically related to the CanineCV identified in dogs, wolves and a badger from Europe, USA, Argentina and China. Nine CAdV were partially sequenced and phylogenetic analysis showed a separate branch for the oldest CAdV-2 identified (1995). From the results obtained in this study population, CanineCV and CAdV coinfections in dogs with parvoviral enteritis did not result in more severe disease.
This retrospective study aimed to evaluate the clinicopathological changes in a population of cats tested for feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV), in an Italian ...Veterinary University Hospital, in the period between January 2002 and May 2016. During the period of 14 years, 1834 cats were tested, and of these 241/1834 (13.1%) were positive for FIV antibodies and 92/1834 (5%) cats were positive for FeLV antigen. These data confirm the presence of a high prevalence of these viruses on Italian territory. To the authors’ knowledge, this study describes findings that have never been evaluated before, such as iron status in retrovirus-infected cats and urinalysis in FeLV-positive cats. In this study, FIV-positive cats were more likely to have higher serum protein concentration and lower albumin-globulin ratio than other groups of cats. Lower urine specific gravity and higher urine protein to creatinine ratio were also detected for FIV-positive cats when compared with negative and healthy cats. FeLV-positive cats were more likely to have cytopenia, decreased haemoglobin, haematocrit and RBC compared with other groups of cats. The data obtained underline the importance of considering retroviral infections in the presence of a broad spectrum of risk factors and laboratory anomalies.
Parvoviruses of carnivores include three closely related autonomous parvoviruses: canine parvovirus (CPV), feline panleukopenia virus (FPV) and mink enteritis virus (MEV). These viruses cause a ...variety of serious diseases, especially in young patients, since they have a remarkable predilection for replication in rapidly dividing cells. FPV is not the only parvovirus species which infects cats; in addition to MEV, the new variants of canine parvovirus, CPV-2a, 2b and 2c have also penetrated the feline host-range, and they are able to infect and replicate in cats, causing diseases indistinguishable from feline panleukopenia. Furthermore, as cats are susceptible to both CPV-2 and FPV viruses, superinfection and co-infection with multiple parvovirus strains may occur, potentially facilitating recombination and high genetic heterogeneity. In the light of the importance of cats as a potential source of genetic diversity for parvoviruses and, since feline panleukopenia virus has re-emerged as a major cause of mortality in felines, the present study has explored the molecular characteristics of parvovirus strains circulating in cat populations. The most significant findings reported in this study were (a) the detection of mixed infection FPV/CPV with the presence of one parvovirus variant which is a true intermediate between FPV/CPV and (b) the quasispecies cloud size of one CPV sample variant 2c. In conclusion, this study provides new important results about the evolutionary dynamics of CPV infections in cats, showing that CPV has presumably started a new process of readaptation in feline hosts.
In this report the concomitant infection with canine parvovirus type 2 (CPV-2),
Hepatozoon canis
and
Ehrlichia canis
in two puppy dogs from Southern Italy is described. Dogs were referred to a ...veterinary university hospital for the acute onset of lethargy and gastrointestinal signs. A complete clinical and clinicopathological evaluation was carried out and the multiple infection was confirmed by microscopic detection of inclusion bodies in peripheral blood smear, rapid immunoenzymatic tests, indirect fluorescent antibody tests, and molecular assays. Sequence analysis revealed that the CPV-2 identified belonged to the 2c variant and had amino acid residues in the predicted VP2 protein typical of “Asian-like” strains widespread in Asia and occasionally reported in Romania, Nigeria and Italy, particularly in the region of Sicily. Numerous monocytes were infected by both
H. canis
gamonts and
E. canis
morulae, suggesting that this co-infection is not accidental and that
E. canis
preferably infects those cells parasitized by
H. canis
. The clinical presentation of these animals was severe but supportive cares associated with early etiological therapy allowed a good prognosis. Movement of puppies from geographic areas where vector-borne pathogens are endemic must be carefully evaluated and core vaccinations and ectoparasite prevention treatments must be rigorously adopted.
Animals, including wildlife, are part of One-Health concept since many infectious diseases can affect both humans and animals. In this study, 126 red foxes (Vulpes vulpes) from Northern Italy in ...2022–2023 were tested by molecular assays for Protoparvovirus carnivoran 1 (PPVC-1), Canine adenovirus type 1 and 2 (CAdV-1 and CAdV-2), Circovirus canine (CanineCV), Canine distemper virus (CDV), and Leptospira spp. A total of 39 of 126 (30.9%) red foxes were infected with at least one pathogen and five of these were coinfected: 20/126 (15.9%) red foxes tested positive for PPVC-1, 3/126 (2.4%) for CAdV, 20/126 (15.9%) for CanineCV, and 2/126 (1.6%) for Leptospira spp. DNA. No foxes tested positive for CDV RNA. The pathogens identified were genetically analysed. New findings were reported such as a fox with multiple feline panleukopenia virus (FPV) and canine parvovirus type 2b (CPV-2b) infection associated with quasispecies dynamics, typical genetic characteristics of the identified CanineCV, and the first detection in red foxes of Leptospira ST198 related to L. interrogans serogroup Australis. Further studies are necessary to investigate the transmission between domestic animals and wildlife and to understand the role of red foxes in the maintenance of these pathogens not only in the wild but also in urban and peri-urban environments.
Cats are susceptible to feline panleukopenia virus (FPV) and canine parvovirus (CPV) variants 2a, 2b and 2c. Detection of FPV and CPV variants in apparently healthy cats and their persistence in ...white blood cells (WBC) and other tissues when neutralising antibodies are simultaneously present, suggest that parvovirus may persist long-term in the tissues of cats post-infection without causing clinical signs. The aim of this study was to screen a population of 54 cats from Sardinia (Italy) for the presence of both FPV and CPV DNA within buffy coat samples using polymerase chain reaction (PCR). The DNA viral load, genetic diversity, phylogeny and antibody titres against parvoviruses were investigated in the positive cats.
Carnivore protoparvovirus 1 DNA was detected in nine cats (16.7%). Viral DNA was reassembled to FPV in four cats and to CPV (CPV-2b and 2c) in four cats; one subject showed an unusually high genetic complexity with mixed infection involving FPV and CPV-2c. Antibodies against parvovirus were detected in all subjects which tested positive to DNA parvoviruses.
The identification of FPV and CPV DNA in the WBC of asymptomatic cats, despite the presence of specific antibodies against parvoviruses, and the high genetic heterogeneity detected in one sample, confirmed the relevant epidemiological role of cats in parvovirus infection.
Critical illness can be associated with transient alterations in circulating thyroid hormone concentrations, indicating the presence of non-thyroidal illness (NTI). NTI is well described in humans, ...but there are few reports on its occurrence and prognostic significance in dogs. This retrospective study assessed the occurrence of NTI in a population of dogs with systemic inflammatory response syndrome (SIRS) and investigated its association with disease severity (APPLE
scores). A total of 41 SIRS dogs were included and were divided by SIRS origin (non-septic SIRS, n = 10; septic SIRS, n = 41) and final outcome (survivors, n = 37; non-survivors, n = 4). Healthy, age-matched dogs (n = 15) were included as controls. Serum thyroid hormone levels including total T3, free T3, total T4, and reverse T3 were measured upon admission. Compared to controls, there were significant changes in serum thyroid hormone concentrations in SIRS dogs, suggesting the presence of NTI. Septic SIRS dogs had higher APPLE
scores and lower serum thyroid hormones concentrations than those in non-septic SIRS and control dogs. In conclusion, NTI was frequent in dogs with SIRS and may be associated with the presence of sepsis or high illness severity.
We report the detection of canine adenovirus type 1 DNA by real-time PCR technique in an oral sample of an Italian wolf (Canis lupus italicus). Genetic characterization of the virus revealed a strict ...relationship with viruses detected in dogs (Canis lupus familiaris), wolves, and red foxes (Vulpes vulpes), suggesting that transmission between wild animals and dogs had occurred.
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