A serologic survey of wild felids from central west Saudi Arabia

Forty-five wildcats (Felis silvestris), 17 sand cats (Felis margarita), and 17 feral domestic cats were captured in central west Saudi Arabia, between May 1998 and April 2000, with the aim to assess their exposure to feline immunodeficiency virus/puma lentivirus (FIV/PLV), feline leukaemia virus (FeLV), feline herpesvirus (FHV-1), feline calicivirus (FCV), feline coronavirus (FCoV), and feline panleukopenia virus (FPLV). Serologic prevalence in wildcats, sand cats, and feral domestic cats were respectively: 6%, 0%, 8% for FIV/PLV; 3%, 8%, 0% for FeLV; 5%, 0%, 15% for FHV-1; 25%, 0%, 39% for FCV; 10%, 0%, 0% for FCoV; and 5%, 0%, 8% for FPLV. We recorded the first case of FeLV antigenemia in a wild sand cat. Positive results to FIV/PLV in wildcats and feral cats confirmed the occurrence of a feline lentivirus in the sampled population.     

Use of a duplex-PCR assay to screen for Feline Herpesvirus-1 and Chlamydophila spp. in mucosal swabs from cats

Fifty-four ocular and forty-six pharyngeal swabs, collected from 54 cats with respiratory syndrome, were analyzed by duplex-PCR to evaluate the presence of Feline Herpesvirus type 1 and Chlamydophila spp. Both pathogens are in the population of cats and as four cats were positive only in ocular swabs and three only in pharyngeal ones, it is deduced that a correct diagnostic approach has to foresee the dispatch to the laboratory of both swabs. Furthermore, all chlamydophila strains analysed by endonuclease restriction were classified as Chlamydophila felis.     

Prevalence of flea infestation in dogs and cats in Hungary combined with a survey of owner awareness

A survey was conducted in order to gain current information on flea species (Siphonaptera: Pulicidae) infesting dogs and cats living in urban and rural areas of Hungary, along with data on the factors that affect the presence, distribution and seasonality of infestation. In addition, owner awareness of flea infestation was evaluated. Practitioners in 13 veterinary clinics were asked to examine all dogs and cats attending the clinic and to collect fleas, when present, on 2 days in each month from December 2005 to November 2006. They also completed a questionnaire for each animal examined. A total of 319 dogs (14.1%) were found to be infested; the highest prevalence (27.1%) of infestation on dogs occurred in August and the lowest (5.4%) in May. Prevalence of fleas on cats was higher (22.9%); the highest (35.0%) and lowest (8.1%) prevalences occurred in July and April, respectively. Fleas were more prevalent in rural (387/1924 animals, 20.2%) than in urban (161/1343 animals, 12.0%) areas. Three species, Ctenocephalides felis (Bouché), Ctenocephalides canis (Curtis) and Pulex irritans L., were found. On dogs, the prevalence of C. canis alone was 53.0%, whereas that of C. felis alone was 36.0%. Only 19 specimens of P. irritans were found on 14 dogs from rural habitats only. Prevalence of C. felis only on cats was 94.3%; the remaining cats were infested with either C. canis or with mixed infestations of C. felis and C. canis. More than half (51.4%) of the owners of infested dogs and cats had not used flea control products in the past year or more, and five times as many owners in rural than urban areas had not used flea control products in the same period. Very few owners reported having attempted to kill fleas in their animals' environment; instead, they believed that fleas were acquired from other cats or dogs.     

Polymerase chain reaction detection of Cytauxzoon felis from field-collected ticks and sequence analysis of the small subunit and internal transcribed spacer 1 region of the ribosomal RNA gene

Cytauxzoon felis produces a disease in domestic cats in the Midwest (U.S.A.), which often leads to a fatal outcome. Although the clinical disease process is well described, there are still many unanswered questions about this organism. For example, it is unknown whether species of ticks other than Dermacentor variabilis can serve as vectors for transmission. With recent reports of surviving cats from limited geographic areas, another relevant question is the potential for genetically less virulent organism strains. This study evaluated 352 individual or pooled tick samples (1,362 total ticks) for the presence of C. felis small subunit ribosomal RNA and internal transcribed spacer 1 (ITS-1) region genes using a polymerase chain reaction (PCR). These ticks were collected from dogs and cats in several Missouri counties, including 10 from cats diagnosed with cytauxzoonosis. Only 3 positive C. felis samples were identified in Amblyomma americanum nymphs, and there was very limited genetic variation noted in both genes. The small number of positive samples did not allow the study to determine which PCR analysis was more sensitive. This is the first known report of ITS-1 gene identification and sequencing for C. felis. It is also the first published investigation of genetic variation in C. felis.     

Structural insights into calicivirus attachment and uncoating

The Caliciviridae family comprises positive-sense RNA viruses of medical and veterinary significance. In humans, caliciviruses are a major cause of acute gastroenteritis, while in animals respiratory illness, conjunctivitis, stomatitis, and hemorrhagic disease are documented. Investigation of virus-host interactions is limited by a lack of culture systems for many viruses in this family. Feline calicivirus (FCV), a member of the Vesivirus genus, provides a tractable model, since it may be propagated in cell culture. Feline junctional adhesion molecule 1 (fJAM-1) was recently identified as a functional receptor for FCV. We have analyzed the structure of this virus-receptor complex by cryo-electron microscopy and three-dimensional image reconstruction, combined with fitting of homology modeled high-resolution coordinates. We show that domain 1 of fJAM-1 binds to the outer face of the P2 domain of the FCV capsid protein VP1, inducing conformational changes in the viral capsid. This study provides the first structural view of a native calicivirus-protein receptor complex and insights into the mechanisms of virus attachment and uncoating.     

Entry of feline calicivirus is dependent on clathrin-mediated endocytosis and acidification in endosomes

Feline calicivirus is a major causative agent of respiratory disease in cats. It is also one of the few cultivatable members of Caliciviridae. We have examined the entry process of feline calicivirus (FCV). An earlier study demonstrated that acidification in endosomes may be required. We have confirmed this observation and expanded upon it, demonstrating, using drugs to inhibit the various endocytic pathways and dominant-negative mutants, that FCV infects cells via clathrin-mediated endocytosis. We have also observed that FCV permeabilizes cell membranes early during infection to allow the co-entry of toxins such as alpha-sarcin. Inhibitors of endosome acidification such as chloroquine and bafilomycin A1 blocked this permeabilization event, demonstrating that acidification is required for uncoating of the genome and access to the cytoplasm.     

Efficacy of commercial vaccines for protecting guinea pigs against Bordetella bronchiseptica pneumonia

Autogenous bacterins are recommended to protect guinea pigs (Cavia porcellus) against pneumonia due to Bordetella bronchiseptica. Bordetella vaccines are available commercially for several other animal species. The substantial antigenic cross-reactivity among Bordetella isolates from various animal species suggests that immunity resulting from use of these vaccines might protect guinea pigs. Groups of ten individually housed Hartley guinea pigs from a colony free of Bordetella were vaccinated with one of two commercial porcine B. bronchiseptica vaccines, a human DPT vaccine (which includes a Bordetella pertussis component), or an autogenous B. bronchiseptica bacterin. Twenty-one days following vaccination, the animals were challenged with an intranasal dose of 10(6) virulent B. bronchiseptica cells. The animals were euthanized and necropsied 15 days after challenge. The nares, nasopharynx, distal trachea and lungs were cultured. All nonvaccinated control animals developed acute signs of pneumonia, while none of the vaccinated animals developed clinical signs of disease or gross lesions. The frequency of B. bronchiseptica isolation from the lungs of animals in each vaccine group was reduced. However, approximately 70% of all animals in each vaccine group harbored B. bronchiseptica in the trachea, and almost all harbored B bronchiseptica in the nares and nasopharynx. The porcine vaccines appeared to afford protection against acute pulmonary disease in the guinea pig.     

First evidence of feline herpesvirus, calicivirus, parvovirus, and Ehrlichia exposure in Brazilian free-ranging felids

Serum samples from 18 pumas (Puma concolor), one ocelot (Leopardus pardalis), and two little spotted cats (Leopardus tigrinus) collected from free-ranging animals in Brazil between 1998 and 2004 were tested by indirect immunofluorescence (IFA) for antibodies to feline herpesvirus 1 (FHV 1), calicivirus (FCV), coronavirus (FCoV), parvo-virus (FPV), Ehrlichia canis, Anaplasma pha-gocytophilum, and Bartonella henselae. Serum samples also were tested, by Western blot and ELISA, for feline leukemia virus (FeLV) specific antibodies and antigen, respectively, by Western blot for antibodies to feline immunodeficiency virus (FIV), and by indirect ELISA for antibodies to puma lentivirus (PLV). Antibodies to FHV 1, FCV, FCoV, FPV, FeLV, FIV, PLV or related viruses, and to B. henselae were detected. Furthermore, high-titered antibodies to E. canis or a closely related agent were detected in a puma for the first time.     

Prevalence of feline viral antibodies in random-source laboratory cats

Over a period of 1973 to 1979, a serologic survey of virus infections was conducted on feline sera collected in four universities which located in different prefectures; Obihiro, Saitama, Kanagawa and Tokyo. A significant hemagglutination-inhibition (HI) antibody titer of 1 : 8 or higher to feline panleukopenia virus (FPLV) was detected in 130 (58%) of the 226 sera used. No remarkable difference in the HI antibody prevalence in cats to FPLV was recognized by years or localities. Of a total of 188 cats tested, 99 (53%) presented positive serum neutralizing (SN) antibody titers to the No. 1 strain of feline calicivirus (FCV). Especially in Kanagawa, 17 (77%) of the 22 cats had positive SN titers. However, only 42 (22%) of the 188 sera showed positive SN titers to the Kyoritsu strain of FCV. Such lower positivity in the cats was observed with 13% in the SN test to human reovirus type 3 (Reo-3). The incidence of positive SN antibodies to feline rhinotracheitis virus (FRV) also remained in low values of 20 to 27% with the exception of high percentage of 86 in Tokyo. The dissemination of FPLV, FRV, FCV and Reo-3 was briefly discussed in relation with the age distribution of viral antibodies in cats.     

Helicobacter felis and Helicobacter bizzozeronii induce gastric parietal cell loss in Mongolian gerbils

Non-pylori helicobacter infections are associated with gastritis, gastric ulcers and MALT lymphomas in man. Approximately 50% of these are caused by helicobacters commonly found in dogs and cats, including Helicobacter felis, Helicobacter bizzozeronii and H. salomonis. In contrast to Helicobacter pylori, the virulence mechanisms of these species are unknown. In this study the virulence of H. felis, H. bizzozeronii and H. salomonis was investigated in Mongolian gerbils. Female SPF gerbils were inoculated intragastrically with H. felis, H. bizzozeronii or H. salomonis and sacrificed 3 weeks later. Fundus and antrum samples were taken for bacterial detection by PCR. A longitudinal strip covering all stomach regions was taken for histology. Gastric colonization, inflammation, apoptosis, loss of parietal cells and cell proliferation were assessed. Controls and H. salomonis inoculated gerbils were negative in PCR. H. felis and H. bizzozeronii inoculated animals were positive. H. felis inoculated animals showed loss of parietal cells extending from the limiting ridge into the fundus. A high cell proliferation rate was noticed in the mucosal area devoid of parietal cells. A dense band of apoptotic cells and large numbers of Helicobacter bacteria were seen at the transition zone between affected and normal parietal cells. In H. bizzozeronii infected gerbils, this was less pronounced. Focal apoptotic loss of gastric epithelial cells was spatially associated with the presence of bacteria especially in H. felis and to a lesser extent in H. bizzozeronii infected gerbils. This loss of cells may lead to intestinal metaplasia.     

Phenotypic and Genomic Analysis of Hypervirulent Human-associated Bordetella bronchiseptica

ABSTRACT: BACKGROUND: B. bronchiseptica infections are usually associated with wild or domesticated animals, but infrequently with humans. A recent phylogenetic analysis distinguished two distinct B. bronchiseptica subpopulations, designated complexes I and IV [1]. Complex IV isolates appear to have a bias for infecting humans; however, little is known regarding their epidemiology, virulence properties, or comparative genomics. RESULTS: Here we report a characterization of the virulence of human-associated complex IV B. bronchiseptica strains. In in vitro cytotoxicity assays, complex IV strains showed increased cytotoxicity in comparison to a panel of complex I strains. Some complex IV isolates were remarkably cytotoxic, resulting in LDH release levels in A549 cells that were 10- to 20-fold greater than complex I strains. In vivo, a subset of complex IV strains was found to be hypervirulent, with an increased ability to cause lethal pulmonary infections in mice. Hypercytotoxicity in vitro and hypervirulence in vivo were both dependent on the activity of the bsc T3SS and the BteA effector. To clarify differences between lineages, representative complex IV isolates were sequenced and their genomes were compared to complex I isolates. Although our analysis showed there were no genomic sequences that can be considered unique to complex IV strains, there were several loci that were predominantly found in complex IV isolates. CONCLUSION: Our observations reveal a T3SS-dependent hypervirulence phenotype in human-associated complex IV isolates, highlighting the need for further studies on the epidemiology and evolutionary dynamics of this B. bronchiseptica lineage.     

Feline viruses in wildcats from Scotland

Few data are available on the prevalence of feline viruses in European wildcats (Felis silvestris). Previous surveys have indicated that wildcats may be infected with the common viruses of domestic cats, apart from feline immunodeficiency virus (FIV). In the present study, 50 wildcats trapped throughout Scotland (UK) between August 1992 and January 1997 were tested for evidence of viral infection. All were negative for FIV by several serological or virological methods. By contrast, 10% of the cats were positive for feline leukemia virus (FeLV) antigen and infectious virus was isolated from 13% of a smaller subset. Of the wildcats tested for respiratory viruses, 25% yielded feline calicivirus (FCV) and although no feline herpesvirus was isolated, 16% of the samples had neutralizing antibodies to this virus. Antibodies to feline coronavirus (FCoV) were found in 6% of samples. Feline foamy virus (FFV) was an incidental finding in 33% of samples tested. This study confirms that wildcats in Scotland are commonly infected with the major viruses of the domestic cat, except for FIV.     

Exposure to disease agents in the endangered Iberian lynx (Lynx pardinus)

The Iberian lynx (Lynx pardinus) is the most endangered felid species in the world. Lynx populations have decreased dramatically in size and distribution in the last four decades, thus becoming increasingly vulnerable to catastrophic events such as epizooties. From 1989 to 2000, serum samples were obtained from 48 free-ranging lynx captured in the Doñana National Park (DNP, n?=?31) and mountains of Sierra Morena (SM, n?=?17) in southern Spain. Samples were tested for antibodies against Toxoplasma gondii, feline herpesvirus 1 (FHV-1), feline calicivirus (FCV), feline/canine parvovirus (FPV/CPV), feline coronavirus, feline immunodeficiency virus (FIV), feline leukaemia virus and canine distemper virus (CDV) and for FeLV p27 antigen, to document baseline exposure levels. Antibodies against T. gondii were detected in 44% of lynx, with a significantly greater prevalence in DNP (61%) than in SM (12%). In DNP, prevalence was significantly higher in adult (81%) than in juvenile and sub-adult (41%) lynx, but no such difference was observed in SM. Low prevalences (≤11%) of minimally positive titres were found for FHV-1, FCV and FPV/CPV. This, combined with the lack of evidence for exposure to CDV, FIV and FeLV, suggests that these lynx populations are naïve and might be vulnerable to a disease outbreak in the future. Because of the reduced size of lynx populations, the documented low level of genetic variation (particularly in the DNP population) coupled with the recently documented state of immune depletion in a majority of necropsied lynx, it is important to better understand the threat and potential impact that disease agents might pose for the conservation of this endangered species. Future surveillance programs must include possible disease reservoir hosts such as domestic cats and dogs and other wild carnivores.     

Seroepidemiology of upper respiratory tract disease in the desert tortoise in the western Mojave Desert of California

Several factors have combined with an upper respiratory tract disease (URTD) to produce declines on some population numbers of desert tortoises (Gopherus agassizii) in the western USA. This study was designed to determine the seroepidemiology of URTD in a population of wild adult tortoises at the Desert Tortoise Research Natural Area (DTNA) study site in Kern County (California, USA). Prior to initiation of the study, there was a dramatic decline in the number of individuals in this population. At each individual time point, samples were obtained from 12 to 20 tortoises with radiotransmitters during winter, spring, summer, and fall from 1992 through 1995. During the course of the study, 35 animals were sampled at one or more times. Only 10 animals were available for consistent monitoring throughout the 4 yr period. Specific antibody (Ab) levels to Mycoplasma agassizii were determined for individual tortoises by an enzyme-linked immunosorbent assay (ELISA) test. Specific Ab levels were not influenced by the gender of the tortoise. Levels of Ab and distribution of ELISA+, ELISA- and suspect animals were not consistently affected by season within a single year or for a season among the study years. Significantly more tortoises presented with clinical signs in 1992 and 1995. The profile of ELISA+ animals with clinical signs shifted from 5% (1992) to 42% (1995). In 1992, 52% of tortoises lacked clinical signs and were ELISA-. In 1995, this category accounted for only 19% of tortoises. Based on the results of this study, we conclude that URTD was present in this population as evidenced by the presence of ELISA+ individual animals, and that the infectious agent is still present as evidenced by seroconversion of previously ELISA- animals during the course of the study. There is evidence to suggest that animals may remain ELISA+ without showing overt disease, a clinical pattern consistent with the chronic nature of most mycoplasmal infections. Further, there are trends suggesting that the clinical expression of disease may be cyclical. Continued monitoring of this population could provide valuable information concerning the spread of URTD in wild tortoise populations.     

Viral infections in free-living populations of the European wildcat

While the importance of viral infections is well studied in domestic cats, only limited information is available on their occurence and prevalence in the European wildcat (Felis silvestris silvestris). The aim of this study was to determine the prevalence of antibodies to feline coronavirus (FCoV), calicivirus (FCV), herpesvirus (FHV), parvovirus (FPV), immunodeficiency virus (FIV), leukemia virus (FeLV), and FeLV antigenemia in 51 European wildcat sera. Samples were collected between 1996 and 1997 from wildcat populations in France, Switzerland, and Germany. Antibodies to FCoV were detected in two cats (4%) and FCoV RNA was detected in feces of one of these two cats. Antibodies to FCV, FHV and FPV were found at relatively low frequencies of 16%, 4%, and 2%, respectively. Antibodies to FIV were not detected. Although antigen and antibodies to FeLV were detected in 49%, and 75%, respectively, no evidence of FeLV-associated pathology was found. From the low prevalence of FCoV, FCV, FHV and FPV infections and from the fact that the European wildcats live solitarily, it was concluded that these viral infections do not spread readily within a population. Therefore, it may be assumed that release into the wild of European wildcats bred in captivity would not bring about a high risk of introducing of these viral infections to the free-ranging wildcats. As an exception, wildcats should be tested for absence of FIV infection before release if they were at risk to acquire this infection from domestic cats.     

Determination of an antigen suitable for enzyme-linked immunosorbent assay of the antibody to Bordetella bronchiseptica in guinea pigs

To establish an enzyme-linked immunosorbent assay (ELISA) technique for the serological diagnosis of infections caused by Bordetella bronchiseptica (B. bronchiseptica) in guinea pigs, the authors recently assessed the usefulness of three antigen preparations derived from the bacterial cell components: sonication antigen (S-Ag), cell surface antigen (C-Ag) and lipopolysaccharide antigen (L-Ag). The use of S-Ag for ELISA resulted in the most sensitive detection of the antibody to B. bronchiseptica from guinea pig sera immunized with killed bacteria and sera derived from naturally infected guinea pigs. Like C-Ag, S-Ag was highly specific, showing no cross-reactivity with Pasteurella multocida. Assessment of antibody formations in animals with experimentally induced infection using the three antigen preparations revealed that the antibody to S-Ag was formed earlier than antibodies to the other two antigen preparations following growth of the bacterium in the lungs. These results indicate that ELISA with S-Ag as an antigen is a useful tool for the serological diagnosis of infection by B. bronchiseptica.     

Prevalence of Chlamydophila felis by PCR among healthy pet cats in Italy

Conjunctival swabs were taken from 60 healthy pet cats and tested for Chlamydophila felis by PCR assays to amplify the ompA, omp2 and groEL genes. Chlamydial DNA was detected in 2 (3.3%) cats, one of which had been vaccinated against C. felis eight months before sample collection. The nucleotide and predicted amino acid sequences of three genes from two cats showed 100% identity with the same regions amplified from conjunctival swabs of cats in the same geographic area.     

A possible new piroplasm in lions from the Republic of South Africa

A small piroplasm was detected in blood smears from lions (Panthera leo) in the Kruger National Park (KNP; Republic of South Africa) during 1991/1992. The parasite was identified provisionally as Babesia felis, but sera from these lions tested negative to B. felis antigen in the indirect immunofluorescent antibody test (IFAT). Blood from an infected lion was subsequently subinoculated into a domestic cat and two leopards in an attempt to identify the parasite. A lion also was infected with B. felis (from a cat). Serum samples collected from these animals were tested against B. felis, the KNP small piroplasm, and Cytauxzoon felis antigen in the IFAT. The serological results indicate that the KNP small piroplasm isolated from the lion is probably a distinct species from B. felis and C. felis.     

Serologic and virologic surveys on feline herpesvirus and feline calicivirus infections in cats for experimental use

Serologic survey and virus isolation of feline herpesvirus (FHV) and feline calicivirus (FCV) were performed on cats used for research at the Laboratory Animal Research Centre, The University of Tsukuba, over the period from 1978 to 1981. Of the 507 mature and immature cats, 4 months old or older, 102 (20.1%) had HI antibody against FHV and 412 (81.3%) SN antibody against FCV. Some 23 (16.2%) and 76 (53.5%) kittens among 142 younger than 4 months had antibodies against FHV and FCV, respectively. Both the antibodies in kittens were considered to be maternally derived. The FCV antibody rate was especially high in cats weighing 2.5 kg (males) and 2.0 kg (females) or more, which were regarded as 8 to 10 months of age. An attempt was made to isolate the viruses from the oropharynx and conjunctiva of clinically healthy mature or immature cats and kittens. As the result, either one or both of the viruses were isolated from 31 of 75 mature and immature cats, and isolation rates of FHV and FCV were 6.7% and 36.0%, respectively. On the other hand, no virus was detectable in 16 kittens.