FCoV Viral Sequences of Systemically Infected Healthy Cats Lack Gene Mutations Previously Linked to the Development of FIP.

Feline infectious peritonitis (FIP)-the deadliest infectious disease of young cats in shelters or catteries-is induced by highly virulent feline coronaviruses (FCoVs) emerging in infected hosts after mutations of less virulent FCoVs. Previous studies have shown that some mutations in the open reading frames (ORF) 3c and 7b and the spike (S) gene have implications for the development of FIP, but mainly indirectly, likely also due to their association with systemic spread. The aim of the present study was to determine whether FCoV detected in organs of experimentally FCoV infected healthy cats carry some of these mutations.

Genetic diversity and phenotypic associations of feline caliciviruses from cats in Switzerland.

Feline calicivirus (FCV) is a common viral pathogen in domestic cats worldwide. The variable regions of the capsid (VP1) gene of FCV have one of the highest recorded rates of molecular evolution. Understanding the genetic diversity and phylogeny of FCV is a prerequisite to exploring the epidemiology and pathogenesis of this virus and to the development of efficacious vaccine strategies.

Molecular characterization and virus neutralization patterns of severe, non-epizootic forms of feline calicivirus infections resembling virulent systemic disease in cats in Switzerland and in Liechtenstein.

Feline calicivirus (FCV) infections are associated with oral ulceration, chronic stomatitis and a limping syndrome. Epizootic outbreaks of virulent systemic disease (VSD) have been reported in the USA and Europe. Here, the molecular characterization and neutralization patterns of FCV isolates from cases of severe, non-epizootic infection associated with skin ulceration and edema are presented.

Gammaretrovirus-specific antibodies in free-ranging and captive Namibian cheetahs.

The cheetah population in Namibia is the largest free-ranging population in the world and a key population for research regarding the health status of this species. We used serological methods and quantitative real-time PCR to test free-ranging and captive Namibian cheetahs for the presence of feline leukemia virus (FeLV), a gammaretrovirus that can be highly aggressive in populations with low genetic diversity, such as cheetahs. We also assessed the presence of antibodies to other gammaretroviruses and the responses to a FeLV vaccine developed for domestic cats.

Evaluation of the effect of short-term treatment with the integrase inhibitor raltegravir (Isentress) on the course of progressive feline leukemia virus infection.

Cats persistently infected with the gammaretrovirus feline leukemia virus (FeLV) are at risk to die within months to years from FeLV-associated disease, such as immunosuppression, anemia or lymphoma/leukemia. The integrase inhibitor raltegravir has been demonstrated to reduce FeLV replication in vitro. The aim of the present study was to investigate raltegravir in vivo for its safety and efficacy to suppress FeLV replication.

First evidence of hemoplasma infection in free-ranging Namibian cheetahs (Acinonyx jubatus).

Infections with feline hemotropic mycoplasmas (hemoplasmas) have been documented in domestic cats and free-ranging feline species with high prevalences in Iberian lynxes (Lynx pardinus), Eurasian lynxes (Lynx lynx), European wildcats (Felis silvestris silvestris), African lions (Panthera leo) in Tanzania and domestic cats in South Africa. The prevalence of hemoplasmas has not yet been investigated in free-ranging felids in southern Africa. In this study we screened 73 blood samples from 61 cheetahs in central Namibia for the presence of hemoplasmas using quantitative real-time PCR.

Stimulation with a class A CpG oligonucleotide enhances resistance to infection with feline viruses from five different families.

Domestic cats are commonly affected by viral pathogens that induce lengthy infections with fatal outcomes. Prevention of viral propagation is of primordial importance in shelters and catteries, where cats from different backgrounds have narrow contacts. Oligonucleotides (ODN) containing cytosine-phosphate-guanosine motifs of class A (CpG-A) are highly potent synthetic inducers of innate antiviral mechanisms.

Quantification of the humoral immune response and hemoplasma blood and tissue loads in cats coinfected with 'Candidatus Mycoplasma haemominutum' and feline leukemia virus.

'Candidatus Mycoplasma haemominutum' (CMhm) is a hemotropic mycoplasma (aka hemoplasma) of domestic cats and wild felids. In a transmission study, we exposed eight specified pathogen-free cats to blood from Iberian lynxes (Lynx pardinus) infected with CMhm. The cats were coinfected with feline leukemia virus (FeLV) from an Iberian lynx or with a prototype FeLV.

In vitro inhibition of feline leukaemia virus infection by synthetic peptides derived from the transmembrane domain.

Background: The feline leukaemia virus (FeLV) is a gammaretrovirus commonly affecting cats. Infection with this virus often leads to fatal outcomes and, so far, no cure is available for this disease. Synthetic peptides with structures mimicking the transmembrane protein of the viral surface proteins hold the potential to effectively interfere with viral entry by hampering the fusion of viral and host cell membranes and constitute a novel approach for the treatment of infections with retroviruses.

Quantification and molecular characterization of the feline leukemia virus A receptor.

Virus receptors and their expression patterns on the cell surface determine the cell tropism of the virus, host susceptibility and the pathogenesis of the infection. Feline thiamine transport protein 1 (fTHTR1) has been identified as the receptor for feline leukemia virus (FeLV) A. The goal of the present study was to develop a quantitative, TaqMan real-time PCR assay to investigate fTHTR1 mRNA expression in tissues of uninfected and FeLV-infected cats, cats of different ages, in tumor tissues and leukocyte subsets.

Inhibition of Feline leukemia virus replication by the integrase inhibitor Raltegravir.

The oncogenic gammaretrovirus Feline leukemia virus (FeLV) has been the leading cause of death among domestic cats until the introduction of efficient diagnostics and vaccines in the late 1980s. So far, no efficient treatment for viremic animals is available. Hence, use of the FeLV model to evaluate antiretroviral therapies applied to HIV is a timely task.

Housing and care of laboratory cats: from requirements to practice.

Increased public awareness of the welfare and well-being of laboratory animals in biomedical research and related ethical considerations inspired us to review recent developments and recommendations for the care and housing of laboratory cats. The present review focuses on the practical requirements for maintaining domestic cats as laboratory animals - from the construction of animal shelters to the termination of an experiment. An excellent standard of housing and care will reduce the bias of experimental results due to stress.

Feline leukemia virus outbreak in the critically endangered Iberian lynx (Lynx pardinus): high-throughput sequencing of envelope variable region A and experimental transmission.

The Iberian lynx is the most endangered felid species. During winter/spring 2006/7, a feline leukemia virus (FeLV) outbreak of unexpected virulence killed about 2/3 of the infected Iberian lynxes. All FeLV-positive animals were co-infected with feline hemoplasmas.

Identification, molecular characterization, and occurrence of two bovine hemoplasma species in Swiss cattle and development of real-time TaqMan quantitative PCR assays for diagnosis of bovine hemoplasma infections.

Concomitantly with an outbreak of fatal anaplasmosis in a cattle herd in Switzerland in 2002, we detected two bovine hemoplasma species in diseased animals: Mycoplasma wenyonii (formerly Eperythrozoon wenyonii) and a second, novel bovine hemoplasma species later designated "Candidatus Mycoplasma haemobos" (synonym, "Candidatus Mycoplasma haemobovis"). The second species was characterized by a shorter 16S rRNA gene. The aims of the present study were to provide a detailed molecular characterization of this species, to develop specific quantitative real-time PCR assays for the two bovine hemoplasma species, and to apply these assays in order to evaluate the prevalence and clinical significance of the hemoplasmas.

Importance of canine distemper virus (CDV) infection in free-ranging Iberian lynxes (Lynx pardinus).

Canine distemper virus (CDV) is a morbillivirus that is the etiological agent of one of the most important viral diseases affecting canids and an expanding range of other carnivores. Using real-time RT-PCR, CDV RNA was detected in organs of an Iberian lynx (Lynx pardinus) found dead in the Doñana National Park, Southwestern Andalusia, Spain. This finding may be of great importance for the conservation of the species; at present the Iberian lynx is the most critically endangered wild felid.

Dominance of highly divergent feline leukemia virus A progeny variants in a cat with recurrent viremia and fatal lymphoma.

Background: In a cat that had ostensibly recovered from feline leukemia virus (FeLV) infection, we observed the reappearance of the virus and the development of fatal lymphoma 8.5 years after the initial experimental exposure to FeLV-A/Glasgow-1. The goals of the present study were to investigate this FeLV reoccurrence and molecularly characterize the progeny viruses.

Quantitative TaqMan real-time PCR assays for gene expression normalisation in feline tissues.

Background: Gene expression analysis is an important tool in contemporary research, with real-time PCR as the method of choice for quantifying transcription levels. Co-analysis of suitable reference genes is crucial for accurate expression normalisation. Reference gene expression may vary, e.

Feline leukemia virus infection: a threat for the survival of the critically endangered Iberian lynx (Lynx pardinus).

The Iberian lynx (Lynx pardinus) is considered the most endangered felid species in the world. To date, less than 200 animals remain in the wild. Low numbers and genetic uniformity may contribute to render this species particularly susceptible to infectious diseases.

Exposure of cats to low doses of FeLV: seroconversion as the sole parameter of infection.

In felids, feline leukemia virus (FeLV) infection results in a variety of outcomes that range from abortive (virus readily eliminated and never detectable) to progressive infection (persistent viremia and viral shedding). Recently, a novel outcome was postulated for low FeLV infectious doses. Naïve cats exposed to faeces of persistently infected cats seroconverted, indicating infection, but remained negative for provirus and p27 antigen in blood.

Molecular Investigations of Rickettsia helvetica infection in dogs, foxes, humans, and Ixodes ticks.

Rickettsia helvetica, a tick-borne member of the spotted-fever-group rickettsiae, is a suspected pathogen in humans; however, its role in animals is unknown. The aims of this study were to establish a R. helvetica-specific real-time TaqMan PCR assay and apply it to the analysis of tick vectors (to determine potential exposure risk) and blood samples from Canidae and humans (to determine prevalence of infection).

Feline leukemia virus and other pathogens as important threats to the survival of the critically endangered Iberian lynx (Lynx pardinus).

Background: The Iberian lynx (Lynx pardinus) is considered the most endangered felid species in the world. In order to save this species, the Spanish authorities implemented a captive breeding program recruiting lynxes from the wild. In this context, a retrospective survey on prevalence of selected feline pathogens in free-ranging lynxes was initiated.

The kinetics of feline leukaemia virus shedding in experimentally infected cats are associated with infection outcome.

Feline leukaemia virus (FeLV) infection in felids results mainly from oronasal exposure to infectious saliva and nasal secretions, but the potential for viral transmission through faeces and urine has not been completely characterized. In order to assess and compare potential FeLV transmission routes, we determined the viral kinetics in plasma, saliva, faeces and urine during early experimental FeLV infection (up to week 15 post-exposure) in specific pathogen-free cats. In addition to monitoring p27 antigen levels measured by ELISA, we evaluated the presence of infectious particles by cell culture assays and quantified viral RNA loads by a quantitative real-time TaqMan polymerase chain reaction.

Absolute quantitation of feline leukemia virus proviral DNA and viral RNA loads by TaqMan real-time PCR and RT-PCR.

Sensitive TaqMan real-time polymerase chain reaction (PCR)-based methods have been developed recently for the detection and quantitation of feline leukemia virus (FeLV) proviral DNA in infected cats. In this chapter, we outline the design and implementation of a TaqMan real-time PCR assay to quantify total FeLV proviral and viral RNA loads in infected cats. The assay is designed to amplify all three FeLV subtypes (A-C), but not FeLV-related endogenous retroviral sequences.