scholarly journals Serum Samples from Co-Infected and Domestic Cat Field Isolates Nonspecifically Bind FIV and Other Antigens in Enzyme-Linked Immunosorbent Assays

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 665
Author(s):  
Alex Moskaluk ◽  
Mary Nehring ◽  
Sue VandeWoude

We evaluated enzyme-linked immunosorbent assay (ELISA) specificity for measuring seroantibody responses to two types of retroviral infections in domestic cats: feline immunodeficiency virus (FIV) and feline foamy virus (FFV). We compared the seroreactivity of specific pathogen-free (SPF) cat sera, sera from SPF cats inoculated with either FIV or FFV, and field isolates (e.g., shelter or privately owned cats). Sera from SPF cats experimentally infected with the cognate virus had significantly lower background in both FIV and FFV ELISAs compared to sera from negative field isolates. ELISA values for SPF cats exposed to either FIV or FFV tended to have higher OD values on the opposite ELISA antigen plate. FIV nonspecific background absorbance was greater than that of FFV, and 10 of 15 sera samples from FIV seronegative field samples were measured in the indeterminant range. These findings highlight that exposure to off-target pathogens elicit antibodies that may nonspecifically bind to antigens used in binding assays; therefore, validation using sera from SPF animals exposed during controlled infection results in the setting of a cutoff value that may be inappropriately low when applied to field samples. Our work also suggests that infection of domestic cats with pathogens other than FIV results in antibodies that cross-react with the FIV Gag antigen.

2018 ◽  
Vol 27 (2) ◽  
pp. 232-236 ◽  
Author(s):  
Andressa Maria Rorato Nascimento de Matos ◽  
Eloiza Teles Caldart ◽  
Fernanda Pinto Ferreira ◽  
Keila Clarine Monteiro ◽  
Marielen de Souza ◽  
...  

Abstract The aim of this study were to detect antibodies anti-Leishmania spp. and anti-Trypanosoma cruzi in two different populations of domestic cats (Felis catus domesticus) from North Paraná referred for surgical castration and to determine which characteristics of the animals studied may be associated with seropositivity. Serum samples from 679 cats were analyzed using enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence antibody test (IFAT) in series. Associations between age, sex, race, year of care and animal group were verified using the simple logistic regression. Percentage of 8.5% (58/679) of cats were positive for Leishmania spp. and 7.6% (51/673) for T. cruzi by the tests ELISA and IFAT. Animals collected by non-governmental animal protection organizations presented more seropositivity for Leishmania spp. (p<0.0001). Results shown that Leishmania spp. and T. cruzi are present in domestic cats in the northern part of the state of Paraná, as well as, owners of non-governmental animal protection organizations may be more exposed to leishmaniasis when compared to other animal owners evaluated in the present study.


Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 772
Author(s):  
Anna Michelitsch ◽  
Donata Hoffmann ◽  
Kerstin Wernike ◽  
Martin Beer

Domestic cats (Felis catus) are popular companion animals that live in close contact with their human owners. Therefore, the risk of a trans-species spreading event between domestic cats and humans is ever-present. Shortly after the emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its rapid spread around the world, the role of domestic cats in the transmission cycle was questioned. In the present study, the first large-scale survey of antibody occurrence in the domestic cat population in Germany was conducted, in order to assess the incidence of naturally occurring human to cat transmission of SARS-CoV-2. A total of 920 serum samples, which were collected from April to September of 2020, were screened by an indirect multispecies ELISA. Positive samples were verified using an indirect immunofluorescence test (iIFT) and additionally tested for neutralizing antibodies. Furthermore, serum samples were screened for antibodies against feline coronavirus (FCoV), in order to rule out cross-reactivity in the described test systems. Overall, 0.69% (6/920) of serum samples were found to be positive for antibodies against SARS-CoV-2 by ELISA and iIFT. Two of these reactive sera also displayed neutralizing antibodies. No cross-reactivity with FCoV-specific antibodies was observed. The finding of SARS-CoV-2 antibody-positive serum samples in the domestic cat population of Germany, during a period when the incidence of human infection in the country was still rather low, indicates that human-to-cat transmission of SARS-CoV-2 happens, but there is no indication of SARS-CoV-2 circulation in cats.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Simona Kraberger ◽  
Nicholas M Fountain-Jones ◽  
Roderick B Gagne ◽  
Jennifer Malmberg ◽  
Nicholas G Dannemiller ◽  
...  

Abstract Emerging viral outbreaks resulting from host switching is an area of continued scientific interest. Such events can result in disease epidemics or in some cases, clinically silent outcomes. These occurrences are likely relatively common and can serve as tools to better understand disease dynamics, and may result in changes in behavior, fecundity, and, ultimately survival of the host. Feline foamy virus (FFV) is a common retrovirus infecting domestic cats globally, which has also been documented in the North American puma (Puma concolor). The prevalent nature of FFV in domestic cats and its ability to infect wild felids, including puma, provides an ideal system to study cross-species transmission across trophic levels (positions in the food chain), and evolution of pathogens transmitted between individuals following direct contact. Here we present findings from an extensive molecular analysis of FFV in pumas, focused on two locations in Colorado, and in relation to FFV recovered from domestic cats in this and previous studies. Prevalence of FFV in puma was high across the two regions, ∼77 per cent (urban interface site) and ∼48 per cent (rural site). Comparison of FFV from pumas living across three states; Colorado, Florida, and California, indicates FFV is widely distributed across North America. FFV isolated from domestic cats and pumas was not distinguishable at the host level, with FFV sequences sharing &gt;93 per cent nucleotide similarity. Phylogenetic, Bayesian, and recombination analyses of FFV across the two species supports frequent cross-species spillover from domestic cat to puma during the last century, as well as frequent puma-to-puma intraspecific transmission in Colorado, USA. Two FFV variants, distinguished by significant difference in the surface unit of the envelope protein, were commonly found in both hosts. This trait is also shared by simian foamy virus and may represent variation in cell tropism or a unique immune evasion mechanism. This study elucidates evolutionary and cross-species transmission dynamics of a highly prevalent multi-host adapted virus, a system which can further be applied to model spillover and transmission of pathogenic viruses resulting in widespread infection in the new host.


1996 ◽  
Vol 8 (2) ◽  
pp. 196-201 ◽  
Author(s):  
Margaret A. Chambers ◽  
Larry J. Swango ◽  
James C. Wright

An indirect fluorescent antibody (IFA) test was developed using a novel format of Borrelia burgdorferi organisms adhered to a monolayer of cultured endothelial cells derived from an equine tumor. Sensitivity and specificity of the new IFA test for detecting anti- B. burgdorferi antibodies were evaluated using sera from dogs inoculated with live B. burgdorferi or vaccinated with B. burgdorferi bacterin or leptobacterins and from unvaccinated specific-pathogen-free (SPF) dogs. To compare the new IFA test with existing tests, serum samples were submitted to independent laboratories to be tested by enzyme-linked immunosorbent assay (ELISA) and a traditional IFA test. Samples were also tested with 2 commercially available membrane-bound ELISA kits. Both Borrelia-inoculated dogs and dogs vaccinated with B. burgdorferi bacterin developed levels of antibody detectable by the new IFA test. Dogs vaccinated with a combination canine vaccine or leptobacterin for food animal use developed detectable levels of antibody against Leptospira but remained seronegative for Borrelia by the new IFA test, as did the unvaccinated SPF dogs. The new IFA test was sensitive, detecting antibodies against B. burgdorferi as early as 7 days postinoculation. It was also specific, showing no cross-reactivity with anti- Leptospira antibodies induced by vaccination with leptobacterins. The new IFA test compared favorably with both the standardized traditional IFA test and ELISA. Results from both membrane-bound ELISA kits were not consistent when compared with each other or with the new IFA test. The new IFA test had low nonspecific fluorescence, which made it easier to evaluate and reduced the human error and variability of test results.


2008 ◽  
Vol 15 (9) ◽  
pp. 1316-1321 ◽  
Author(s):  
Will L. Goff ◽  
Wendell C. Johnson ◽  
John B. Molloy ◽  
Wayne K. Jorgensen ◽  
Susan J. Waldron ◽  
...  

ABSTRACT A competitive enzyme-linked immunosorbent assay (cELISA) based on a broadly conserved, species-specific, B-cell epitope within the C terminus of Babesia bigemina rhoptry-associated protein 1a was validated for international use. Receiver operating characteristic analysis revealed 16% inhibition as the threshold for a negative result, with an associated specificity of 98.3% and sensitivity of 94.7%. Increasing the threshold to 21% increased the specificity to 100% but modestly decreased the sensitivity to 87.2%. By using 21% inhibition, the positive predictive values ranged from 90.7% (10% prevalence) to 100% (95% prevalence) and the negative predictive values ranged from 97.0% (10% prevalence) to 48.2% (95% prevalence). The assay was able to detect serum antibody as early as 7 days after intravenous inoculation. The cELISA was distributed to five different laboratories along with a reference set of 100 defined bovine serum samples, including known positive, known negative, and field samples. The pairwise concordance among the five laboratories ranged from 100% to 97%, and all kappa values were above 0.8, indicating a high degree of reliability. Overall, the cELISA appears to have the attributes necessary for international application.


Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1009
Author(s):  
Anna Michelitsch ◽  
Jacob Schön ◽  
Donata Hoffmann ◽  
Martin Beer ◽  
Kerstin Wernike

Registered cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in the German human population increased rapidly during the second wave of the SARS-CoV-2 pandemic in winter 2020/21. Since domestic cats are susceptible to SARS-CoV-2, the occurrence of trans-species transmission needs to be monitored. A previous serosurvey during the first wave of the pandemic detected antibodies against SARS-CoV-2 in 0.65% of feline serum samples that were randomly sampled across Germany. In the here-presented follow-up study that was conducted from September 2020 to February 2021, the seroprevalence rose to 1.36% (16/1173). This doubling of the seroprevalence in cats is in line with the rise of reported cases in the human population and indicates a continuous occurrence of trans-species transmission from infected owners to their cats.


2013 ◽  
Vol 20 (4) ◽  
pp. 596-601 ◽  
Author(s):  
Mohamad Alaa Terkawi ◽  
Kyohko Kameyama ◽  
Nazim Hamza Rasul ◽  
Xuean Xuan ◽  
Yoshifumi Nishikawa

ABSTRACTDense granule antigen proteins derived fromToxoplasma gondii(TgGRAs) are potential antigens for the development of diagnostic tools. TgGRA7 and TgGRA14 were detected in the peritoneal fluid ofT. gondii-infected mice, suggesting that TgGRAs may be highly antigenic proteins. Here, TgGRA7 and TgGRA14 were evaluated as candidates for the development of a marker for a rapid diagnostic test. The specificity and sensitivity of purified recombinant proteins of TgGRA7 and TgGRA14 were compared in an indirect enzyme-linked immunosorbent assay (iELISA) using a series of serum samples fromT. gondii-experimentally infected mice and using recombinantT. gondiimajor surface antigen 2 (TgSAG2) as a reference control. The iELISA with TgGRA7 showed the greatest diagnostic accuracy and could detect anti-TgGRA7 antibody in acute and chronic infections. A total of 59 field samples from pigs were also examined by the iELISAs, and the results compared with those of the latex agglutination test (LAT). Among the three recombinant antigens, TgGRA7 had the highest rates of positivity, with significant concordance (88.14) and kappa value (0.76) in comparison with the results using LAT. Furthermore, an immunochromatographic test (ICT) based on recombinant TgGRA7 was developed for rapid detection of antibodies to the infection. The ICT differentiated clearly between sera fromT. gondii-infected mice and uninfected orNeospora caninum-infected mice. Pig sera were examined with the ICT, and the results compared favorably with those of LAT and iELISA for TgGRA7, with kappa values of 0.66 and 0.70 to 0.79, respectively. These data suggest that the ICT based on TgGRA7 is a promising diagnostic tool for routine testing in the clinic and mass screening of samples in the field.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Magdalena Materniak-Kornas ◽  
Tadeusz Frymus ◽  
Martin Löchelt ◽  
Jacek Kuźmak

Abstract Introduction Feline foamy virus (FFVfca) is widespread and its prevalence in naturally infected domestic cats ranges between 30% and 80% worldwide. The infection is persistent, with a sustained antibody response in FFVfca-positive cats; however to date, no defined disease or clinical symptoms have been proved to be associated with it. The goal of the presented study was to determine the prevalence of FFVfca infection in domestic cats in Poland. Material and Methods A total of 223 serum samples collected from domestic cats were tested with a glutathione S-transferase capture ELISA test to detect antibodies specific to capsid (Gag), accessory (Bet) and envelope (Env) FFVfca antigens. A Western blot test was used to confirm the ELISA results. Results The cut-off value for the Gag antigen was established by calculation and evaluation with the immunoblotting assay. The cut-off values for Bet and Env were calculated from the reactivity of Gag-negative samples. The sera of 99 cats (44%) showed reactivity to Gag, those of 80 did so (35.9 %) to Bet, while only 56 samples (25%) were reactive to Env. Only 51 (22.9%) sera were positive for all antigens. The main diagnostic antigen was selected to be Gag. A statistically significant association was found between FFVfca status and the age of the cat. Conclusions This study proved the high seroprevalence of FFVfca in domestic cats in Poland for the first time and confirmed that adult cats are at higher FFVfca infection risk than preadult cats. Its results correspond to those reported from other countries.


1990 ◽  
Vol 2 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Carol House ◽  
Peter E. Mikiciuk ◽  
Mary Lou Beminger

Five serological methods of diagnosing African horse sickness were evaluated, using a battery of serum samples from experimental horses vaccinated and challenged with each serotype of African horse sickness virus (AHSV1 through AHSV9): agar gel immunodiffusion (AGID), indirect fluorescent antibody (IFA), complement fixation (CF), virus neutralization (VN), and enzyme-linked immunosorbent assay (ELISA). The 5 tests were also compared using a panel of field samples, convalescent equine sera with antibodies to domestic equine viral diseases, and sera from horses awaiting export. The ELISA described in this paper was group specific. It did not require calibration with a standard positive serum but did yield elevated values with negative sera that were repeatedly frozen and thawed or heat inactivated. The IFA test was sensitive but could not be used on some field sera as the control cells exhibited fluorescence, possibly due to the animal being recently vaccinated with cell culture material. Sixty-two experimental sera were compared by VN, CF, AGID, and ELISA. Forty sera, 10 positive and 30 negative, were correctly classified by the 5 serologic assays. The 22 remaining sera gave mixed reactions. The AGID had no false positive results but had false negative results for up to 20% of the samples, depending upon the comparison. The VN, CF, and ELISA were similar in their variability. The length of time that virus could be recovered from a viremic blood sample was compared in an evaluation of storage methods for virus isolation samples. Washed erythrocytes were held at 4 C, washed erythrocytes plus stabilizer were held at −70 C, and blood that was drawn into a preservative (oxalate/phenol/glycerol) was held at 4 C. Virus was isolated for 12 months from a sample stored as washed erythrocytes at 4 C but for only 6 months from the same blood stored by the other 2 methods.


1994 ◽  
Vol 28 (3) ◽  
pp. 257-261 ◽  
Author(s):  
H. W. J. Broeders ◽  
J. Groen ◽  
G. van Steenis ◽  
A. D. M. E. Osterhaus

An enzyme-linked immunosorbent assay (ELISA) was developed for the detection and quantification of IgM and IgG serum antibodies to mouse polyomavirus (MPV). To evaluate the potential of this ELISA for the screening of laboratory rodents, serum samples from specific pathogen free (SPF) BALB/c RIVM mice, collected after experimental intraperitoneal infection with MPV, were tested by this assay. The results were compared with those obtained from the same sera in an immunofluorescence assay (IFA) and a haemagglutination inhibition assay (HIA). The ELISA proved to be the most sensitive of the 3 assays, allowing the detection of seropositive animals within 7 days post-infection and giving antibody titres that were about 4 to 8 times higher than those found in the IFA and HIA respectively. More than 5000 serum samples from non-infected specific pathogen free laboratory mice and 90 from 10 SPF N:NIH/RIVM mice experimentally infected with K-papovavirus, were negative in this assay, thus confirming the specificity of the ELISA


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