BACKGROUND: Zoonotic leishmaniosis, caused by the protozoan Leishmania infantum, is a public and animal health problem in Asia, Central and South America, the Middle East and the Mediterranean Basin. Several phlebotomine sand fly species from the subgenus Larroussius are vectors of L. infantum. Data from dogs living in endemic areas of leishmaniosis advocate the use of antibody response to phlebotomine sand fly saliva as an epidemiological biomarker for monitoring vector exposure. The aim of this study was to analyse the exposure of cats to phlebotomine sand flies using detection of IgG antibodies to Phlebotomus perniciosus saliva. The association between phlebotomine sand fly exposure and the presence of Leishmania infection was also investigated. RESULTS: IgG antibodies to P. perniciosus saliva were detected in 167 (47.7%) out of 350 cats; higher antibody levels were present in sera collected during the period of phlebotomine sand fly seasonal activity (OR = 19.44, 95% CI: 9.84-38.41). Cats of 12-35 months had higher antibody levels than younger ones (OR = 3.56, 95% CI: 1.39-9.16); this difference was also significant with older cats (for 36-95 months-old, OR = 9.43, 95% CI: 3.62-24.48; for older than 95 months, OR = 9.68, 95% CI: 3.92-23.91). Leishmania spp. DNA was detected in the blood of 24 (6.9%) cats, while antibodies to L. infantum were detected in three (0.9%). Only one cat was positive to Leishmania by both techniques. Cats presenting IgG antibodies to P. perniciosus had a significantly higher risk of being positive for Leishmania infection. CONCLUSIONS: To our knowledge, this is the first study demonstrating anti-sand fly saliva antibodies in cats. The evaluation of the contact of this animal species with the vector is important to the development of prophylactic measures directed to cats, with the aim of reducing the prevalence of infection in an endemic area. Therefore, studies evaluating whether the use of imidacloprid/flumethrin collars reduces the frequency of P. perniciosus bites in cats are needed. It is also important to evaluate if there is a correlation between the number of phlebotomine sand fly bites and IgG antibody levels.
- MeSH
- imunoglobulin G imunologie MeSH
- kočky MeSH
- Leishmania infantum imunologie MeSH
- leishmanióza viscerální veterinární MeSH
- nemoci koček imunologie parazitologie MeSH
- Phlebotomus imunologie MeSH
- rizikové faktory MeSH
- sliny imunologie MeSH
- tvorba protilátek MeSH
- zvířata MeSH
- Check Tag
- kočky MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Infection with feline immunodeficiency virus (FIV) causes an immunosuppressive disease whose consequences are less severe if cats are co-infected with an attenuated FIV strain (PLV). We use virus diversity measurements, which reflect replication ability and the virus response to various conditions, to test whether diversity of virulent FIV in lymphoid tissues is altered in the presence of PLV. Our data consisted of the 3' half of the FIV genome from three tissues of animals infected with FIV alone, or with FIV and PLV, sequenced by 454 technology. RESULTS: Since rare variants dominate virus populations, we had to carefully distinguish sequence variation from errors due to experimental protocols and sequencing. We considered an exponential-normal convolution model used for background correction of microarray data, and modified it to formulate an error correction approach for minor allele frequencies derived from high-throughput sequencing. Similar to accounting for over-dispersion in counts, this accounts for error-inflated variability in frequencies - and quite effectively reproduces empirically observed distributions. After obtaining error-corrected minor allele frequencies, we applied ANalysis Of VAriance (ANOVA) based on a linear mixed model and found that conserved sites and transition frequencies in FIV genes differ among tissues of dual and single infected cats. Furthermore, analysis of minor allele frequencies at individual FIV genome sites revealed 242 sites significantly affected by infection status (dual vs. single) or infection status by tissue interaction. All together, our results demonstrated a decrease in FIV diversity in bone marrow in the presence of PLV. Importantly, these effects were weakened or undetectable when error correction was performed with other approaches (thresholding of minor allele frequencies; probabilistic clustering of reads). We also queried the data for cytidine deaminase activity on the viral genome, which causes an asymmetric increase in G to A substitutions, but found no evidence for this host defense strategy. CONCLUSIONS: Our error correction approach for minor allele frequencies (more sensitive and computationally efficient than other algorithms) and our statistical treatment of variation (ANOVA) were critical for effective use of high-throughput sequencing data in understanding viral diversity. We found that co-infection with PLV shifts FIV diversity from bone marrow to lymph node and spleen.
- MeSH
- algoritmy MeSH
- DNA virů genetika MeSH
- interpretace statistických dat * MeSH
- kočičí AIDS genetika imunologie virologie MeSH
- kočky MeSH
- nemoci koček genetika imunologie přenos virologie MeSH
- statistické modely * MeSH
- virus kočičí imunodeficience klasifikace genetika patogenita MeSH
- vysoce účinné nukleotidové sekvenování metody MeSH
- zvířata MeSH
- Check Tag
- kočky MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Research Support, N.I.H., Extramural MeSH
- MeSH
- feces parazitologie MeSH
- Giardia lamblia izolace a purifikace MeSH
- giardiáza diagnóza imunologie veterinární MeSH
- kočky MeSH
- nemoci koček diagnóza imunologie parazitologie MeSH
- nemoci psů diagnóza imunologie parazitologie MeSH
- protilátky protozoální analýza MeSH
- psi MeSH
- zvířata MeSH
- Check Tag
- kočky MeSH
- psi MeSH
- zvířata MeSH
- Publikační typ
- srovnávací studie MeSH
