Immune characterization of long pentraxin 3 in pigs infected with influenza virus

Long pentraxin 3 (PTX3) is a conserved pattern-recognition secreted protein and a host-defence-related component of the humoral innate immune system. The aim of the present study was to characterize swine PTX3 (SwPTX3) protein expression in influenza virus infected pigs. First, we performed in silico studies to evaluate the cross-reactivity of PTX3 human antibodies against SwPTX3. Secondly, we used in vitro analysis to detect SwPTX3 presence in swine bone marrow dendritic cells (SwBMDC) upon stimulation with different agents by Western blot and immunofluorescence. Finally, the levels of SwPTX3 were assessed in experimental infection of pigs with different strains of influenza virus. This is a novel study where the expression of SwPTX3 was evaluated in the context of a pathogen infection. The initial characterization of SwPTX3 in influenza virus infected pigs contributes to understand the role of PTX proteins in the immune response.     

Recent advances in the epidemiology,diagnosis and control of diseases caused by porcine circovirus type 2

Post-weaning multisystemic wasting syndrome (PMWS) emerged as a significant disease affecting pig production in the 1990s although the causal agent, porcine circovirus type 2 (PCV2), and the disease itself, had existed in swine for many years prior to this. The important multifactorial ‘triggers’ of PMWS include the immune and infection status of the sow, the timing of PCV2 infection, variations in the virulence of PCV2, co-infections, immune modulation as well as host genetics and management factors. In terms of diagnosis, histopathological examination and the detection of PCV2 within lymphoid tissue remains the ‘gold standard’ as quantitative PCR techniques are currently not specific or sensitive enough. The recent commercial availability of PCV2 vaccines provides an excellent tool for reducing the impact of PMWS and other porcine circovirus-related diseases. This review assesses recent advances in the epidemiology, diagnosis and control of PMWS.     

Post-fire production of mushrooms in Pinus pinaster forests using classificatory models

This study was aimed at describing post-fire mushroom production in a Mediterranean ecosystem dominated by Pinus pinaster Ait. in the northwest of Spain and assessing the results by classificatory models. During the autumn periods of 2003–2006, fruit bodies from 115 fungal taxa were collected in burned and unburned areas and were further grouped into the following categories: saprotrophic/mycorrhizal; and edible/non-edible. After wildfires, a significant reduction in the number of fungal species and fruit body biomass production was observed. Based on this relevant information, the first simple classificatory model for this aim is provided. Nine alternative models based on classifications according to combinations of edibility and functional groups were fitted, and four fruiting body biomass production classes were defined as possible responses. As explanatory factors, time after fire and climatic variables significantly related to fruit body production were included. The best predictive results were obtained for edible and edible-mycorrhizal models, for which the correct classification rate of production classes was between 92 and 85 %. Moreover, the models obtained were applied to analyse the effect of time after fire on fungal production. Mycorrhizal and edible fungal production after fire was classified into the lowest class, whereas saprotrophic and non-edible species followed a contrary trend. The classificatory models can be useful to optimise management and harvest of these increasingly appreciated non-timber forest resources.     

Comparative pharmacokinetics of enrofloxacin in mice, rats, rabbits, sheep, and cows.

OBJECTIVE: To compare pharmacokinetic variables of enrofloxacin (ENR) after IV administration in mice, rats, rabbits, sheep, and cows and to perform allometric analysis of ENR. ANIMALS: 47 mice, 5 rats, 5 rabbits, 5 sheep, and 5 cows. PROCEDURE: Serially obtained plasma samples were assayed for ENR concentration, using high-performance liquid chromatography. In vitro plasma protein binding was determined by ultrafiltration. Plasma ENR concentration versus time curves were fitted by use of nonlinear least-squared regression analysis. Pharmacokinetic variables were correlated further with body weight. RESULTS: In all species studied, the best fit was obtained for a two-compartment open model; ENR half-life ranged from 89 minutes in mice to 169 minutes in cows. Volume of distribution was large in all species studied, with values ranging from 10.5 L/kg in mice to 1.5 L/kg in sheep. Body clearance ranged from 68.1 ml/min/kg for mice to 4.6 ml/min/kg for sheep. Unbound ENR was found to be (mean +/- SD) 58+/-2, 50+/-6, 50+/-2, 31+/-2, and 40+/-3% in plasma of mice, rats, rabbits, sheep, and cows, respectively. The only pharmacokinetic variables that could be correlated with body weight were elimination half-life, clearance, and volume of distribution. Allometric exponents denoting proportionality of half-life, body clearance, and volume of distribution with body weight were 0.06, 0.82, and 0.90, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: An allometric approach could provide a suitable method for determining a scale for ENR pharmacokinetics among various mammalian species. This would faciliatate the administration of appropriate doses of ENR to all animals.     

Tympanic ossicles and pharyngeal arches

We have performed a study on 11 human embryos regarding the development of the tympanic ossicles and their relationship with the first pharyngeal arch. After performing measurements to date the embryos and foetuses chronologically, we performed a meticulous dissection of the temporal bones. Subsequently, they were fixed in 10% formol, decalcified with 2% nitric acid, embedded in Paraplast, sectioned in 7-mm sequences and stained with Martin's trichrome technique. In the 21- and 24-mm cranium-raquis (CR) length human embryos, we have observed the head of the malleus and the body of the incus close to Meckel's cartilage, in addition to the handle of the malleus, the long limb of the incus and the stapes. Between them there was a mesenchymal band inside the primordium of the tympanic cavity. In the 27-mm CR embryo, the various components of the malleus and incus were fusing, and in the 30-mm CR embryo the union was complete. From our observations, we can conclude that the malleus and the incus are derived from the first and second pharyngeal arches.     

Genetic Structure of the Population of Pepino mosaic virus Infecting Tomato Crops in Spain

ABSTRACT The population structure of Pepino mosaic virus (PepMV), which has caused severe epidemics in tomato in Spain since 2000, was analyzed. Isolates were characterized by the nucleotide sequence of the triple gene block and coat protein gene and, for a subset of isolates, a part of the RNA-dependent RNA polymerase gene. The full-length sequence of the genomic RNA of a Solanum muricatum isolate from Peru also was determined. In spite of high symptom diversity, the Spanish population of PepMV mostly comprised highly similar isolates belonging to the strain reported in Europe (European tomato strain), which has been the most prevalent genotype in Spain. The Spanish PepMV population was not structured spatially or temporally. Also, isolates highly similar to those from nontomato hosts from Peru (Peruvian strain) or to isolate US2 from the United States (US2 strain) were detected at lower frequency relative to the European strain. These two strains were detected in peninsular Spain only in 2004, but the Peruvian strain has been detected in the Canary Islands since 2000. These results suggest that PepMV was introduced into Spain more than once. Isolates from the Peruvian and US2 strains always were found in mixed infections with the European tomato strain, and interstrain recombinants were detected. The presence of different strains of the virus, and of recombinant isolates, should be considered for the development of control strategies based on genetic resistance.     

Differential interactions of virulent and non-virulent H. parasuis strains with na?ve or swine influenza virus pre-infected dendritic cells

Pigs possess a microbiota in the upper respiratory tract that includes Haemophilus parasuis. Pigs are also considered the reservoir of influenza viruses and infection with this virus commonly results in increased impact of bacterial infections, including those by H. parasuis. However, the mechanisms involved in host innate responses towards H. parasuis and their implications in a co-infection with influenza virus are unknown. Therefore, the ability of a non-virulent H. parasuis serovar 3 (SW114) and a virulent serovar 5 (Nagasaki) strains to interact with porcine bone marrow dendritic cells (poBMDC) and their modulation in a co-infection with swine influenza virus (SwIV) H3N2 was examined. At 1 hour post infection (hpi), SW114 interaction with poBMDC was higher than that of Nagasaki, while at 8 hpi both strains showed similar levels of interaction. The co-infection with H3N2 SwIV and either SW114 or Nagasaki induced higher levels of IL-1β, TNF-α, IL-6, IL-12 and IL-10 compared to mock or H3N2 SwIV infection alone. Moreover, IL-12 and IFN-α secretion differentially increased in cells co-infected with H3N2 SwIV and Nagasaki. These results pave the way for understanding the differences in the interaction of non-virulent and virulent strains of H. parasuis with the swine immune system and their modulation in a viral co-infection.     

An Analysis of Host Adaptation and Its Relationship with Virulence in Cucumber mosaic virus

ABSTRACT The host range of a pathogen can have special consequences on its evolution and the evolution of its virulence. For generalists, adaptation to different hosts may be conditioned by different trade-offs in the pathogen's life history and be affected by evolutionary processes that shape pathogen populations. We have examined adaptation of Cucumber mosaic virus (CMV) to different hosts, and analyzed the relationship between host adaptation and virulence. For this, six CMV isolates from central Spain from three different hosts were compared for the ability to multiply and to affect host growth. These analyses were done before and after an experimental evolution process consisting of 10 serial passages in the original host of the isolate. The differential capacity to infect different hosts was compatible with host adaptation. However, the capacity to multiply in different hosts did not provide evidence of host adaptation and was not improved after 10 passages, suggesting that fitness of the natural population of CMV was at, or near to, its maximum. No relationship was found between capacity of multiplication and virulence in any of the three different hosts. These results suggest that the "trade-off" model for the evolution of virulence may not apply to CMV.     

Serum acute phase proteins as biomarkers of pleuritis and cranio-ventral pulmonary consolidation in slaughter-aged pigs

The purpose of this study was to investigate the relationship between the existence of lung lesions in pigs at slaughter and the concentration of the serum acute phase proteins (APP), haptoglobin (Hp), pig-major acute protein (Pig-MAP) and C-reactive protein (CRP). A total of 24 pig farms were selected out of a larger farm database previously screened to study risk factors associated with pleuritis and cranio-ventral pulmonary consolidation (CVPC) lesions at slaughter-aged pigs in Spain. The farms were classified as “pleuritis negative (P−) or positive (P+)” and as “CVPC negative (M−) or positive (M+)” and divided into four groups according to a 2X2 factorial design (P−M−, P−M+, P+M−, P+M+). Also at slaughter, blood from 20 randomly selected pigs from each farm was collected. Obtained serum samples were used to measure acute phase proteins. All APP concentrations were significantly higher for M+ farms than for M− ones. However, only Hp and Pig-MAP showed significantly higher concentrations for P+ farms than for P− ones. Pig-MAP was the most sensitive biomarker since it was able to clearly discriminate between P−/P+ and M−/M+ groups (p < 0.001 in both cases). Hp was an excellent marker for pleuritis and good for CVPC lesions. CRP was able to discriminate for CVPC lesions but not for pleuritis. The present results indicate that Pig-MAP and, possibly Hp, may be used as potential markers to characterise and discriminate respiratory lesions in swine herds at slaughter.