Artículos de revista IdAB - IdAB Aldizkari artikuluak

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Open Access
Bap, a Staphylococcus aureus surface protein involved in biofilm formation
(American Society for Microbiology, 2001) Cucarella, Carme; Solano Goñi, Cristina; Valle Turrillas, Jaione; Amorena Zabalza, Beatriz; Lasa Uzcudun, Íñigo; Penadés, José R.; Nekazaritza Ekoizpena; Producción Agraria; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua
Identification of new genes involved in biofilm formation is needed to understand the molecular basis of strain variation and the pathogenic mechanisms implicated in chronic staphylococcal infections. A biofilm-producing Staphylococcus aureus isolate was used to generate biofilm-negative transposon (Tn917) insertion mutants. Two mutants were found with a significant decrease in attachment to inert surfaces (early adherence), intercellular adhesion, and biofilm formation. The transposon was inserted at the same locus in both mutants. This locus (bap [for biofilm associated protein]) encodes a novel cell wall associated protein of 2,276 amino acids (Bap), which shows global organizational similarities to surface proteins of gram-negative (Pseudomonas aeruginosa andSalmonella enterica serovar Typhi) and gram-positive (Enteroccocus faecalis) microorganisms. Bap's core region represents 52% of the protein and consists of 13 successive nearly identical repeats, each containing 86 amino acids. bap was present in a small fraction of bovine mastitis isolates (5% of the 350S. aureus isolates tested), but it was absent from the 75 clinical human S. aureus isolates analyzed. All staphylococcal isolates harboring bap were highly adherent and strong biofilm producers. In a mouse infection modelbap was involved in pathogenesis, causing a persistent infection.
Open Access
Calcium inhibits bap-dependent multicellular behavior in Staphylococcus aureus
(American Society for Microbiology, 2004) Arrizubieta Balerdi, María Jesús; Toledo Arana, Alejandro; Amorena Zabalza, Beatriz; Penadés, José R.; Lasa Uzcudun, Íñigo; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua
Bap (biofilm-associated protein) is a 254-kDa staphylococcal surface protein implicated in formation of biofilms by staphylococci isolated from chronic mastitis infections. The presence of potential EF-hand motifs in the amino acid sequence of Bap prompted us to investigate the effect of calcium on the multicellular behavior of Bap-expressing staphylococci. We found that addition of millimolar amounts of calcium to the growth media inhibited intercellular adhesion of and biofilm formation by Bap-positive strain V329. Addition of manganese, but not addition of magnesium, also inhibited biofilm formation, whereas bacterial aggregation in liquid media was greatly enhanced by metal-chelating agents. In contrast, calcium or chelating agents had virtually no effect on the aggregation of Bap-deficient strain M556. The biofilm elicited by insertion of bap into the chromosome of a biofilm-negative strain exhibited a similar dependence on the calcium concentration, indicating that the observed calcium inhibition was an inherent property of the Bap-mediated biofilms. Site-directed mutagenesis of two of the putative EF-hand domains resulted in a mutant strain that was capable of forming a biofilm but whose biofilm was not inhibited by calcium. Our results indicate that Bap binds Ca2+ with low affinity and that Ca2+ binding renders the protein noncompetent for biofilm formation and for intercellular adhesion. The fact that calcium inhibition of Bap-mediated multicellular behavior takes place in vitro at concentrations similar to those found in milk serum supports the possibility that this inhibition is relevant to the pathogenesis and/or epidemiology of the bacteria in the mastitis process.
Open Access
Characterization of ovine A3Z1 restriction properties against small ruminant lentiviruses (SRLVs)
(MDPI, 2017) Pablo Maiso, Lorena de; Glaría Ezquer, Idoia; Crespo Otano, Helena; Nistal Villán, Estanislao; Andrésdóttir, Valgerdur; Andrés Cara, Damián de; Amorena Zabalza, Beatriz; Reina Arias, Ramsés; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Intrinsic factors of the innate immune system include the apolipoprotein B editing enzyme catalytic polypeptide-like 3 (APOBEC3) protein family. APOBEC3 inhibits replication of different virus families by cytosine deamination of viral DNA and a not fully characterized cytosine deamination-independent mechanism. Sheep are susceptible to small ruminant lentivirus (SRLVs) infection and contain three APOBEC3 genes encoding four proteins (A3Z1, Z2, Z3 and Z2-Z3) with yet not deeply described antiviral properties. Using sheep blood monocytes and in vitro-derived macrophages, we found that A3Z1 expression is associated with lower viral replication in this cellular type. A3Z1 transcripts may also contain spliced variants (A3Z1Tr) lacking the cytidine deaminase motif. A3Z1 exogenous expression in fully permissive fibroblast-like cells restricted SRLVs infection while A3Z1Tr allowed infection. A3Z1Tr was induced after SRLVs infection or stimulation of blood-derived macrophages with interferon gamma (IFN- ). Interaction between truncated isoform and native A3Z1 protein was detected as well as incorporation of both proteins into virions. A3Z1 and A3Z1Tr interacted with SRLVs Vif, but this interaction was not associated with degradative properties. Similar A3Z1 truncated isoforms were also present in human and monkey cells suggesting a conserved alternative splicing regulation in primates. A3Z1-mediated retroviral restriction could be constrained by different means, including gene expression and specific alternative splicing regulation, leading to truncated protein isoforms lacking a cytidine-deaminase motif.
Open Access
Detection of PrPSc in lung and mammary gland is favored by the presence of Visna/maedi virus lesions in naturally coinfected sheep
(EDP Sciences, 2010) Salazar, Eider; Monleón, Eva; Bolea, Rosa; Acín, Cristina; Pérez, Marta María; Álvarez, Neila; Leginagoikoa, Iratxe; Juste, Ramón; Minguijón, Esmeralda; Reina Arias, Ramsés; Glaría Ezquer, Idoia; Berriatua, Eduardo; Andrés Cara, Damián de; Badiola, Juan José; Amorena Zabalza, Beatriz; Luján, Lluís; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
There are few reports on the pathogenesis of scrapie (Sc) and Visna/maedi virus (VMV) coinfections. The aim of this work was to study in vivo as well as post mortem both diseases in 91 sheep. Diagnosis of Sc and VMV infections allowed the distribution of animals into five groups according to the presence (+) or absence ( ) of infection by Sc and VMV: Sc /VMV , Sc /VMV+, Sc+/VMV and Sc+/ VMV+. The latter was divided into two subgroups, with and without VMV-induced lymphoid follicle hyperplasia (LFH), respectively. In both the lung and mammary gland, PrPSc deposits were found in the germinal center of hyperplasic lymphoid follicles in the subgroup of Sc+/VMV+ having VMV-induced LFH. This detection was always associated with (and likely preceded by) PrPSc observation in the corresponding lymph nodes. No PrPSc was found in other VMV-associated lesions. Animals suffering from scrapie had a statistically significantly lower mean age than the scrapie free animals at the time of death, with no apparent VMV influence. ARQ/ARQ genotype was the most abundant among the 91 ewes and the most frequent in scrapie-affected sheep. VMV infection does not seem to influence the scrapie risk group distribution among animals from the five groups established in this work. Altogether, these data indicate that certain VMVinduced lesions can favor PrPSc deposits in Sc non-target organs such as the lung and the mammary gland, making this coinfection an interesting field that warrants further research for a better comprehension of the pathogenesis of both diseases.
Open Access
The enterococcal surface protein, Esp, is involved in Enterococcus faecalis biofilm formation
(American Society for Microbiology, 2001) Toledo Arana, Alejandro; Valle Turrillas, Jaione; Solano Goñi, Cristina; Arrizubieta Balerdi, María Jesús; Cucarella, Carme; Lamata, Marta; Amorena Zabalza, Beatriz; Leiva, José; Penadés, José R.; Lasa Uzcudun, Íñigo; Nekazaritza Ekoizpena; Producción Agraria; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua
The enterococcal surface protein, Esp, is a high-molecular-weight surface protein of unknown function whose frequency is significantly increased among infection-derived Enterococcus faecalis isolates. In this work, a global structural similarity was found between Bap, a biofilm-associated protein of Staphylococcus aureus, and Esp. Analysis of the relationship between the presence of the Esp-encoding gene (esp) and the biofilm formation capacity in E. faecalis demonstrated that the presence of the esp gene is highly associated (P < 0.0001) with the capacity of E. faecalis to form a biofilm on a polystyrene surface, since 93.5% of the E. faecalis esp-positive isolates were capable of forming a biofilm. Moreover, none of the E. faecalis esp-deficient isolates were biofilm producers. Depending on the E. faecalis isolate, insertional mutagenesis of esp caused either a complete loss of the biofilm formation phenotype or no apparent phenotypic defect. Complementation studies revealed that Esp expression in an E. faecalis esp-deficient strain promoted primary attachment and biofilm formation on polystyrene and polyvinyl chloride plastic from urine collection bags. Together, these results demonstrate that (i) biofilm formation capacity is widespread among clinical E. faecalis isolates, (ii) the biofilm formation capacity is restricted to the E. faecalis strains harboring esp, and (iii) Esp promotes primary attachment and biofilm formation of E. faecalis on abiotic surfaces.
Open Access
Expression of the biofilm-associated protein interferes with host protein receptors of Staphylococcus aureus and alters the infective process
(American Society for Microbiology, 2002) Cucarella, Carme; Tormo Más, María Ángeles; Knecht, Erwin; Amorena Zabalza, Beatriz; Lasa Uzcudun, Íñigo; Foster, Timothy J.; Penadés, José R.; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
The adherence of Staphylococcus aureus to soluble proteins and extracellular-matrix components of the host is one of the key steps in the pathogenesis of staphylococcal infections. S. aureus presents a family of adhesins called MSCRAMMs (microbial surface components recognizing adhesive matrix molecules) that specifically recognize host matrix components. We examined the influence of biofilm-associated protein (Bap) expression on S. aureus adherence to host proteins, epithelial cell cultures, and mammary gland sections and on colonization of the mammary gland in an in vivo infection model. Bap-positive strain V329 showed lower adherence to immobilized fibrinogen and fibronectin than isogenic Bap-deficient strain m556. Bacterial adherence to histological sections of mammary gland and bacterial internalization into 293 cells were significantly lower in the Bap-positive strains. In addition, the Bap-negative strain showed significantly higher colonization in vivo of sheep mammary glands than the Bap-positive strain. Taken together, these results strongly suggest that the expression of the Bap protein interferes with functional properties of the MSCRAMM proteins, preventing initial bacterial attachment to host tissues and cellular internalization.
Open Access
Extensive rearing hinders Maedi-Visna Virus (MVV) infection in sheep
(EDP Sciences, 2006) Leginagoikoa, Iratxe; Juste, Ramón; Barandika, Jesse; Amorena Zabalza, Beatriz; Andrés Cara, Damián de; Luján, Lluís; Badiola, Juan José; Berriatua, Eduardo; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Maedi-Visna Virus (MVV) seroprevalence and its relationship with housing and mode of rearing of replacement ewe-lambs was investigated in 38 non-randomly selected sheep-flocks in Spain. They included extensive lamb-producing Manchega cross-bred flocks raised almost permanently at pasture, semi-intensive Latxa dairy flocks housed 2–8 months/year and intensively raised Assaf dairy flocks housed most time and at higher stocking density in less ventilated buildings than other flocks. Most flocks raised replacement lambs naturally with their dams until weaning and as a separate flock thereafter until lambing at one year of age. Seroprevalence (95% confidence intervals) was 77%, 25% and 5% (4–6) in intensive, semi-intensive and extensive flocks, respectively and the median (interquartile range) flock-seroprevalence was 82% (66–94) in intensive flocks, 31% (14–31) in semi-intensive flocks and 4% (0–7) in extensive flocks. Seroprevalence was lowest in one year-old sheep and increased to flock levels during the year after introduction into the adult flock in most intensive flocks and more gradually in other flocks. Adult flock seroprevalence was associated with housing time but this relationship was not evident within a particular rearing system, indicating that other unknown factors are critical in horizontal MVV-transmission. Low seroprevalence in extensive flocks further supports previous indications that lactogenic MVV-infection is relatively inefficient and horizontal transmission is necessary to ensure long-term maintenance of MVV and this could explain that MVV has not been reported from countries with mainly extensively reared sheep such as Australia and New Zealand. Moreover, it indicates that MVV-control in extensive and semi-intensive flocks can be simple and inexpensive.
Open Access
The extradomain a of fibronectin enhances the efficacy of lipopolysaccharide defective Salmonella bacterins as vaccines in mice
(BioMed Central, 2012) San Román Aberasturi, Beatriz; Lasa Uzcudun, Íñigo; Andrés Cara, Damián de; Amorena Zabalza, Beatriz; Lasarte, Juan José; Grilló Dolset, María Jesús; Garrido González, Victoria; Muñoz Álvaro, Pilar María; Arribillaga, Laura; García Martínez, Begoña; Andrés, Ximena de; Zabaleta Sanz de Acedo, Virginia; Mansilla, Cristina; Farrán Blanch, Inmaculada; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua: IIM10865.RI1-EP12; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The Extradomain A from fibronectin (EDA) has an immunomodulatory role as fusion protein with viral and tumor antigens, but its effect when administered with bacteria has not been assessed. Here, we investigated the adjuvant effect of EDA in mice immunizations against Salmonella enterica subspecies enterica serovar Enteritidis (Salmonella Enteritidis). Since lipopolysaccharide (LPS) is a major virulence factor and the LPS O-polysaccharide (O-PS) is the immunodominant antigen in serological diagnostic tests, Salmonella mutants lacking O-PS (rough mutants) represent an interesting approach for developing new vaccines and diagnostic tests to differentiate infected and vaccinated animals (DIVA tests). Here, antigenic preparations (hot-saline extracts and formalin-inactivated bacterins) from two Salmonella Enteritidis rough mutants, carrying either intact (SE Delta waaL) or deep-defective (SE Delta gal) LPS-Core, were used in combination with EDA. Biotinylated bacterins, in particular SE Delta waaL bacterin, decorated with EDAvidin (EDA and streptavidin fusion protein) improved the protection conferred by hot-saline or bacterins alone and prevented significantly the virulent infection at least to the levels of live attenuated rough mutants. These findings demonstrate the adjuvant effect of EDAvidin when administered with biotinylated bacterins from Salmonella Enteritidis lacking O-PS and the usefulness of BEDA-SE Delta waaL as non-live vaccine in the mouse model.
Open Access
Identification of the ovine mannose receptor and its possible role in Visna/Maedi virus infection
(BioMed Central, 2011) Crespo Otano, Helena; Reina Arias, Ramsés; Glaría Ezquer, Idoia; Ramírez Álvarez, Hugo; Andrés, Ximena de; Jauregui, Paula; Luján, Lluís; Martínez Pomares, Luisa; Amorena Zabalza, Beatriz; Andrés Cara, Damián de; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
This study aims to characterize the mannose receptor (MR) gene in sheep and its role in ovine visna/maedi virus (VMV) infection. The deduced amino acid sequence of ovine MR was compatible with a transmembrane protein having a cysteine-rich ricin-type amino-terminal region, a fibronectin type II repeat, eight tandem C-type lectin carbohydrate-recognition domains (CRD), a transmembrane region, and a cytoplasmic carboxy-terminal tail. The ovine and bovine MR sequences were closer to each other compared to human or swine MR. Concanavalin A (ConA) inhibited VMV productive infection, which was restored by mannan totally in ovine skin fibroblasts (OSF) and partially in blood monocyte-derived macrophages (BMDM), suggesting the involvement of mannosylated residues of the VMV ENV protein in the process. ConA impaired also syncytium formation in OSF transfected with an ENV-encoding pN3-plasmid. MR transcripts were found in two common SRLV targets, BMDM and synovial membrane (GSM) cells, but not in OSF. Viral infection of BMDM and especially GSM cells was inhibited by mannan, strongly suggesting that in these cells the MR is an important route of infection involving VMV Env mannosylated residues. Thus, at least three patterns of viral entry into SRLV-target cells can be proposed, involving mainly MR in GSM cells (target in SRLV-induced arthritis), MR in addition to an alternative route in BMDM (target in SRLV infections), and an alternative route excluding MR in OSF (target in cell culture). Different routes of SRLV infection may thus coexist related to the involvement of MR differential expression.
Open Access
Immunization against small ruminant lentiviruses
(MDPI, 2013) Reina Arias, Ramsés; Andrés Cara, Damián de; Amorena Zabalza, Beatriz; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua: IIQ14064.RI1
Multisystemic disease caused by Small Ruminant Lentiviruses (SRLV) in sheep and goats leads to production losses, to the detriment of animal health and welfare. This, together with the lack of treatments, has triggered interest in exploring different strategies of immunization to control the widely spread SRLV infection and, also, to provide a useful model for HIV vaccines. These strategies involve inactivated whole virus, subunit vaccines, DNA encoding viral proteins in the presence or absence of plasmids encoding immunological adjuvants and naturally or artificially attenuated viruses. In this review, we revisit, comprehensively, the immunization strategies against SRLV and analyze this double edged tool individually, as it may contribute to either controlling or enhancing virus replication and/or disease.
Open Access
In vivo monitoring of Staphylococcus aureus biofilm infections and antimicrobial therapy by [18F]fluoro-deoxyglucose–MicroPET in a mouse model
(American Society for Microbiology, 2014) Garrido González, Victoria; Collantes, María; Barberán, Montserrat; Peñuelas, Iván; Arbizu, Javier; Amorena Zabalza, Beatriz; Grilló Dolset, María Jesús; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua, IIM13002.RI1
A mouse model was developed for in vivo monitoring of infection and the effect of antimicrobial treatment against Staphylococcus aureus biofilms, using the [18F]fluoro-deoxyglucose–MicroPET ([18F]FDG-MicroPET) image technique. In the model, sealed Vialon catheters were briefly precolonized with S. aureus strains ATCC 15981 or V329, which differ in cytotoxic properties and biofilm matrix composition. After subcutaneous implantation of catheters in mice, the S. aureus strain differences found in bacterial counts and the inflammatory reaction triggered were detected by the regular bacteriological and histological procedures and also by [18F]FDG-MicroPET image signal intensity determinations in the infection area and regional lymph node. Moreover, [18F]FDG-MicroPET imaging allowed the monitoring of the rifampin treatment effect, identifying the periods of controlled infection and those of reactivated infection due to the appearance of bacteria naturally resistant to rifampin. Overall, the mouse model developed may be useful for noninvasive in vivo determinations in studies on S. aureus biofilm infections and assessment of new therapeutic approaches.
Open Access
Lack of relationship between Visna/maedi infection and scrapie resistance genetic markers
(Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA), 2014) Salazar, Eider; Berriatua, Eduardo; Pérez, Marta María; Marín, Belén; Acín, Cristina; Martín Burriel, Inmaculada; Reina Arias, Ramsés; Andrés Cara, Damián de; Amorena Zabalza, Beatriz; Badiola, Juan José; Luján, Lluís; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
The relationship between Visna/maedi virus (VMV) antibody status and scrapie genetic resistance of 10,611 Rasa Aragonesa sheep from 17 flocks in Aragón (Spain) was investigated. The fifteen most common PRNP gene haplotypes and genotypes were identified and the genotypes were classified into the corresponding scrapie risk groups (groups 1 to 5). ARQ (93.3%) and ARR (31.8%) were the most common haplotypes and ARQ/ARQ (56%) and ARR/ARQ (25.6%) were the most common genotypes. The frequencies of scrapie risk groups 1, 2, 3, 4 and 5 were 3.3%, 27.3%, 63.5%, 1.2% and 4.8%, respectively. Overall Visna/maedi seroprevalence was 53% and flock seroprevalence ranged between 21-86%. A random effects logistic regression model indicated that sheep VMV serological status (outcome variable) was not associated with any particular scrapie risk group. Instead, VMV seropositivity progressively increased with age, was signif icantly greater in females compared to males and varied between flocks. The absence of a relationship between VMV infection and scrapie genotypes is important for VMV control and specifically for sheep participating in an ELISA-based Visna/maedi control program.
Open Access
Maedi-visna virus infection of ovine mammary epithelial cells
(EDP Sciences, 2006) Bolea, Rosa; Monleón, Eva; Carrasco, Librado; Vargas, Antonia; Andrés Cara, Damián de; Amorena Zabalza, Beatriz; Badiola, Juan José; Luján, Lluís; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
The aim of this work was to perform a complete study of maedi-visna virus (MVV) infected mammary glands of naturally-infected sheep, and to determine if cells other than macrophages undergo a productive viral infection in this organ. Fifteen seropositive and two seronegative ewes were selected from MVV-infected flocks on the basis of clinical indurative mastitis and three sheep from an MVV-free flock. Within the mammary gland, MVV-positive cells were located by immunohistochemistry in the stroma and the epithelial alveolar barrier, most likely the ovine mammary epithelial cells (OMEC) of the acini. In situ hybridization confirmed these findings. Ultrastructural studies showed the presence of lentivirus-like particles budding off the cell surface in the alveolar barrier and also free in the acinar lumen. The presence of mammary histopathological lesions and MVV together with clear indications of productive infection (demonstration of a cytopathic effect in OMEC cultures and infection of co-cultures) were observed in the 15 seropositive and one of the seronegative sheep from the infected flock. These findings demonstrate that the OMEC were infected in vivo and probably underwent productive infection when studied ex-vivo. The OMEC of MVV-free sheep, which had subsequently been infected in vitro with MVV, also showed productive infection when challenged in vitro, confirming the replication of MVV in OMEC in vitro. The presence of MVV-infected OMEC in the mammary gland from infected animals, the productive infection in these OMEC and the release of lentiviral particles to the acinar lumen may have relevance in the pathogenesis and transmission of MVV infection.
Open Access
Mannose receptor may be involved in small ruminant lentivirus pathogenesis
(BioMed Central, 2012) Crespo Otano, Helena; Jauregui, Paula; Glaría Ezquer, Idoia; Sanjosé, Leticia; Polledo, Laura; García Marín, Juan F.; Luján, Lluís; Andrés Cara, Damián de; Amorena Zabalza, Beatriz; Reina Arias, Ramsés; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua: IIQ14064.RI1; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Thirty-one sheep naturally infected with small ruminant lentiviruses (SRLV) of known genotype (A or B), and clinically affected with neurological disease, pneumonia or arthritis were used to analyse mannose receptor (MR) expression (transcript levels) and proviral load in virus target tissues (lung, mammary gland, CNS and carpal joints). Control sheep were SRLV-seropositive asymptomatic (n = 3), seronegative (n = 3) or with chronic listeriosis, pseudotuberculosis or parasitic cysts (n = 1 in each case). MR expression and proviral load increased with the severity of lesions in most analyzed organs of the SRLV infected sheep and was detected in the affected tissue involved in the corresponding clinical disease (CNS, lung and carpal joint in neurological disease, pneumonia and arthritis animal groups, respectively). The increased MR expression appeared to be SRLV specific and may have a role in lentiviral pathogenesis.
Open Access
Ovine TRIM5α can restrict visna/maedi virus
(American Society for Microbiology, 2012) Jauregui, Paula; Crespo Otano, Helena; Glaría Ezquer, Idoia; Luján, Lluís; Contreras, A.; Rosati, Sergio; Andrés Cara, Damián de; Amorena Zabalza, Beatriz; Towers, G. J.; Reina Arias, Ramsés; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua, IIQ14064.RI1
The restrictive properties of tripartite motif-containing 5 alpha (TRIM5α) from small ruminant species have not been explored. Here, we identify highly similar TRIM5α sequences in sheep and goats. Cells transduced with ovine TRIM5α effectively restricted the lentivirus visna/maedi virus DNA synthesis. Proteasome inhibition in cells transduced with ovine TRIM5α restored restricted viral DNA synthesis, suggesting a conserved mechanism of restriction. Identification of TRIM5α active molecular species may open new prophylactic strategies against lentiviral infections.
Open Access
Post-entry blockade of small ruminant lentiviruses by wild ruminants
(BioMed Central, 2016) Sanjosé, Leticia; Crespo Otano, Helena; Blatti-Cardinaux, Laure; Glaría Ezquer, Idoia; Martínez Carrasco, Carlos; Berriatua, Eduardo; Amorena Zabalza, Beatriz; Andrés Cara, Damián de; Bertoni, Giuseppe; Reina Arias, Ramsés; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua: IIQ010449.RI1; Gobierno de Navarra / Nafarroako Gobernua: IIQ14064.RI1; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Small ruminant lentivirus (SRLV) infection causes losses in the small ruminant industry due to reduced animal production and increased replacement rates. Infection of wild ruminants in close contact with infected domestic animals has been proposed to play a role in SRLV epidemiology, but studies are limited and mostly involve hybrids between wild and domestic animals. In this study, SRLV seropositive red deer, roe deer and mouflon were detected through modified ELISA tests, but virus was not successfully amplified using a set of different PCRs. Apparent restriction of SRLV infection in cervids was not related to the presence of neutralizing antibodies. In vitro cultured skin fibroblastic cells from red deer and fallow deer were permissive to the SRLV entry and integration, but produced low quantities of virus. SRLV got rapidly adapted in vitro to blood-derived macrophages and skin fibroblastic cells from red deer but not from fallow deer. Thus, although direct detection of virus was not successfully achieved in vivo, these findings show the potential susceptibility of wild ruminants to SRLV infection in the case of red deer and, on the other hand, an in vivo SRLV restriction in fallow deer. Altogether these results may highlight the importance of surveilling and controlling SRLV infection in domestic as well as in wild ruminants sharing pasture areas, and may provide new natural tools to control SRLV spread in sheep and goats.
Open Access
Role of biofilm-associated protein bap in the pathogenesis of bovine Staphylococcus aureus
(American Society for Microbiology, 2004) Cucarella, Carme; Tormo Más, María Ángeles; Ubeda, Carles; Trotonda, María Pilar; Monzon, Marta; Peris, Cristòfol; Amorena Zabalza, Beatriz; Lasa Uzcudun, Íñigo; Penadés, José R.; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Staphylococcus aureus is a common cause of intramammary infections, which frequently become chronic, associated with the ability of the bacteria to produce biofilm. Here, we report a relationship between the ability to produce chronic bovine mastitis and biofilm formation. We have classified bovine mastitis S. aureus isolates into three groups based on the presence of particular genetic elements required for biofilm formation: group 1 (ica+ bap+), group 2 (ica+, bap negative), and group 3 (ica negative, bap negative). Overall, animals naturally infected with group 1 and 2 isolates had a lower milk somatic cell count than those infected with isolates of group 3. In addition, Bap-positive isolates were significantly more able to colonize and persist in the bovine mammary gland in vivo and were less susceptible to antibiotic treatments when forming biofilms in vitro. Analysis of the structural bap gene revealed the existence of alternate forms of expression of the Bap protein in S. aureus isolates obtained under field conditions throughout the animal's life. The presence of anti-Bap antibodies in serum samples taken from animals with confirmed S. aureus infections indicated the production of Bap during infection. Furthermore, disruption of the ica operon in a bap-positive strain had no effect on in vitro biofilm formation, a finding which strongly suggested that Bap could compensate for the deficiency of the PIA/PNAG product (a biofilm matrix polysaccharide). Altogether, these results demonstrate that, in the bovine intramammary gland, the presence of Bap may facilitate a biofilm formation connected with the persistence of S. aureus.
Open Access
Routes of transmission and consequences of small ruminant lentiviruses (SRLVs) infection and eradication schemes
(EDP Sciences, 2004) Peterhans, Ernst; Greenland, Tim; Badiola, Juan José; Harkiss, Gordon; Bertoni, Giuseppe; Amorena Zabalza, Beatriz; Eliaszewicz, Muriel; Juste, Ramón; Krassnig, Renate; Lafont, Jean Pierre; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Small ruminant lentiviruses (SRLV = maedi-visna in sheep and caprine arthritis encephalitis in goats) are distributed throughout most countries of the world, particularly Europe. Laboratories from 16 European countries established collaborations within the framework of a COST (CO-operation in the field of Scientific and Technical Research) action sponsored by the European Union in order to (i) better organize their research programmes on SRLVs and (ii) to coordinate efforts to combat these two diseases. After five years, a consensus conference – the first one in the veterinary medicine field – concluded the work of this network of laboratories by reviewing the present position and discussing three important questions in the field of SRLVs: routes of transmission, consequences of infection and potential role of eradication programmes at either a European or local level, according to the situation in each country or region. This paper brings together existing information regarding these questions and identifies areas for future research.
Open Access
Small ruminant lentiviruses: genetic variability, tropism and diagnosis
(MDPI, 2013) Ramírez Álvarez, Hugo; Reina Arias, Ramsés; Amorena Zabalza, Beatriz; Andrés Cara, Damián de; Martínez, Humberto A.; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Small ruminant lentiviruses (SRLV) cause a multisystemic chronic disease affecting animal production and welfare. SRLV infections are spread across the world with the exception of Iceland. Success in controlling SRLV spread depends largely on the use of appropriate diagnostic tools, but the existence of a high genetic/antigenic variability among these viruses, the fluctuant levels of antibody against them and the low viral loads found in infected individuals hamper the diagnostic efficacy. SRLV have a marked in vivo tropism towards the monocyte/macrophage lineage and attempts have been made to identify the genome regions involved in tropism, with two main candidates, the LTR and env gene, since LTR contains primer binding sites for viral replication and the env-encoded protein (SU ENV), which mediates the binding of the virus to the host’s cell and has hypervariable regions to escape the humoral immune response. Once inside the host cell, innate immunity may interfere with SRLV replication, but the virus develops counteraction mechanisms to escape, multiply and survive, creating a quasi-species and undergoing compartmentalization events. So far, the mechanisms of organ tropism involved in the development of different disease forms (neurological, arthritic, pulmonary and mammary) are unknown, but different alternatives are proposed. This is an overview of the current state of knowledge on SRLV genetic variability and its implications in tropism as well as in the development of alternative diagnostic assays.
Open Access
Small ruminant macrophage polarization may play a pivotal role on lentiviral infection
(BioMed Central, 2013) Crespo Otano, Helena; Bertolotti, Luigi; Juganaru, Magda; Glaría Ezquer, Idoia; Andrés Cara, Damián de; Amorena Zabalza, Beatriz; Rosati, Sergio; Reina Arias, Ramsés; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua: IIQ14064.RI1; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Small ruminant lentiviruses (SRLV) infect the monocyte/macrophage lineage inducing a long-lasting infection affecting body condition, production and welfare of sheep and goats all over the world. Macrophages play a pivotal role on the host's innate and adaptative immune responses against parasites by becoming differentially activated. Macrophage heterogeneity can tentatively be classified into classically differentiated macrophages (M1) through stimulation with IFN-gamma displaying an inflammatory profile, or can be alternatively differentiated by stimulation with IL-4/IL-13 into M2 macrophages with homeostatic functions. Since infection by SRLV can modulate macrophage functions we explored here whether ovine and caprine macrophages can be segregated into M1 and M2 populations and whether this differential polarization represents differential susceptibility to SRLV infection. We found that like in human and mouse systems, ovine and caprine macrophages can be differentiated with particular stimuli into M1/M2 subpopulations displaying specific markers. In addition, small ruminant macrophages are plastic since M1 differentiated macrophages can express M2 markers when the stimulus changes from IFN-gamma to IL-4. SRLV replication was restricted in M1 macrophages and increased in M2 differentiated macrophages respectively according to viral production. Identification of the infection pathways in macrophage populations may provide new targets for eliciting appropriate immune responses against SRLV infection.