In May 2012, an adult, male bottlenose dolphin (Tursiops truncatus) was found stranded and dead on the Spanish Mediterranean coast. At necropsy, several areas of malacia were macroscopically observed in the periventricular parenchyma of the cerebrum. Microscopically a severe, diffuse, pyogranulomatous, and necrotizing meningoencephalomyelitis was associated with numerous intralesional highly pleomorphic fungal structures. After culture, the fungus, Cunninghamella bertholletiae, was identified by culture and PCR. To our knowledge, this is the first reported case of central nervous system mucormycosis due to Cunninghamella bertholletiae in a cetacean.
Tuberculosis either caused by Mycobacterium bovis or M.?caprae is a significant burden to agricultural industries worldwide. Vaccination of domestic ruminant species such as cattle and goats constitutes a potential tool to support disease control. This review will discuss recent progress made to develop tuberculosis vaccines against domestic ruminants as well as approaches to differentiate vaccinated and infected animals (DIVA) and biomarker discovery studies.
The severity of the acute form of CSF is responsible for the high mortality rate and has been the subject of many studies. Nevertheless, some animals are likely to develop a mild, chronic, or unapparent form of the disease. Paradoxically, this clinical form of the disease has not been well studied, especially regarding its pathogenesis. In this study, we investigated the infection in domestic pigs that is caused by the CSFV Cat01 strain, which is responsible for the 2001-2002 CSFV outbreak in Catalonia, Spain, and which caused mild and nonspecific clinical signs compared to the infection that is caused by another CSFV strain that is responsible for inducing severe clinical symptoms of disease. We assessed the impact of the CSFV infection in the immune system of domestic pigs, mainly on the kinetics of different cytokines, such as IFN-? (innate immunity) and IFN-? (adaptive immune response), during the first weeks after infection. In addition, we evaluated the impact on the induction of the humoral response and its relation to the course of infection and the RNA CSFV viral load. The IFN-? levels in the serum samples from the pigs that developed a milder form of the CSF disease (infected with Cat01 strain) were lower than those that were detected in the pig with severe clinical CSF signs (Margarita strain). After infection with Cat01 strain, the IFN-? levels in response to CSFV were detected in addition to the humoral response. Interestingly, in the serum samples of these animals, we detected the lowest load of CSFV RNA. Similarly, the lowest viral load levels were detected in the tonsils of these pigs. Both the T cells and the humoral response that were generated in most of the pigs that were infected with strain Cat01 may be related to the protection in the symptom progression of CSF against this viral strain. These results explain the antiviral role of IFN-? in the absence of an antibody response. Likewise, these results corroborate the relevance and relationship that exists between the intensity of the T cell response and the protection against CSFV replication. Additionally, these results also explain how the failure to induce optimal levels of humoral and cellular responses after CSFV infection promotes the spread and persistence of the virus.
Background Brucella ceti infections have been increasingly reported in cetaceans. Brucellosis in these animals is associated with meningoencephalitis, abortion, discospondylitis¿, subcutaneous abscesses, endometritis and other pathological conditions B. ceti infections have been frequently described in dolphins from both, the Atlantic and Pacific Oceans. In the Mediterranean Sea, only two reports have been made: one from the Italian Tyrrhenian Sea and the other from the Adriatic Sea.ResultsWe describe the clinical and pathological features of three cases of B. ceti infections in three dolphins stranded in the Mediterranean Catalonian coast. One striped dolphin had neurobrucellosis, showing lethargy, incoordination and lateral swimming due to meningoencephalitis, A B. ceti infected bottlenose dolphin had discospondylitis, and another striped dolphin did not show clinical signs or lesions related to Brucella infection. A detailed characterization of the three B. ceti isolates was performed by bacteriological, molecular, protein and fatty acid analyses.ConclusionsAll the B. ceti strains originating from Mediterranean dolphins cluster together in a distinct phylogenetic clade, close to that formed by B. ceti isolates from dolphins inhabiting the Atlantic Ocean. Our study confirms the severity of pathological signs in stranded dolphins and the relevance of B. ceti as a pathogen in the Mediterranean Sea.
The present study has evaluated the protection conferred by a single subcutaneous dose of a modified vaccinia virus Ankara (MVA) vectored vaccine encoding the Rift Valley Fever virus (RVFV) glycoproteins Gn and Gc in lambs. Three groups of six to seven lambs were immunized as follows: one group received the vaccine (termed rMVA-GnGc), a second group received an MVA vector (vector control) and a third group received saline solution (non-vaccinated control). Fourteen days later, all animals were subcutaneously challenged with 10(5) TCID50 of the virulent RVFV isolate 56/74 and vaccine efficacy assessed using standard endpoints. Two lambs (one from the vaccine group and one from the vector control group) succumbed to RVFV challenge, showing characteristic liver lesions. Lambs from both the vector control and non-vaccinated groups were febrile from days 2 to 5 post challenge (pc) while those in the rMVA-GnGc group showed a single peak of pyrexia at day 3 pc. RVFV RNA was detected in both nasal and oral swabs from days 3 to 7 pc in some lambs from the vector control and non-vaccinated groups, but no viral shedding could be detected in the surviving lambs vaccinated with rMVA-GnGc. Together, the data suggest that a single dose of the rMVA-GnGc vaccine may be sufficient to reduce RVFV shedding and duration of viremia but does not provide sterile immunity nor protection from disease. Further optimization of this vaccine approach in lambs is warranted.
Pigs were immunized with DNA plasmids containing different open reading frames (ORFs) of a porcine reproductive and respiratory syndrome virus (PRRSV) genotype I strain. One group was injected with three inoculations of ORF7, a second group was immunized with three inoculations of plasmids containing ORF5 and ORF6, and a third group was kept as controls. Later, +21 days after the last inoculation, animals were challenged with the homologous strain. After the challenge, PRRSV-specific interferon (IFN)-?-secreting cells and anti-PRRSV IgG antibodies developed faster in DNA vaccinated pigs (p<0.05). However, DNA-immunized pigs showed an exacerbation of the disease compared to the unvaccinated challenged pigs. The data suggest that previous immunization with DNA vaccines against glycoprotein 5 and/or matrix protein of PRRSV, as well as nucleoprotein but to a lesser degree, could result in an exacerbation of the clinical course in terms of fever upon challenge.
The "One world, one health" initiative emphasizes the need for new strategies to control human and animal tuberculosis (TB) based on their shared interface. A good example would be the development of novel universal vaccines against Mycobacterium tuberculosis complex (MTBC) infection. This study uses the goat model, a natural TB host, to assess the protective effectiveness of a new vaccine candidate in combination with Bacillus Calmette-Guerin (BCG) vaccine. Thirty-three goat kids were divided in three groups: Group 1) vaccinated with BCG (week 0), Group 2) vaccinated with BCG and boosted 8 weeks later with a recombinant adenovirus expressing the MTBC antigens Ag85A, TB10.4, TB9.8 and Acr2 (AdTBF), and Group 3) unvaccinated controls. Later on, an endobronchial challenge with a low dose of M. caprae was performed (week 15). After necropsy (week 28), the pulmonary gross pathology was quantified using high resolution Computed Tomography. Small granulomatous pulmonary lesions (< 0.5 cm diameter) were also evaluated through a comprehensive qualitative histopathological analysis. M. caprae CFU were counted from pulmonary lymph nodes. The AdTBF improved the effects of BCG reducing gross lesion volume and bacterial load, as well as increasing weight gain. The number of Ag85A-specific gamma interferon-producing memory T-cells was identified as a predictor of vaccine efficacy. Specific cellular and humoral responses were measured throughout the 13-week post-challenge period, and correlated with the severity of lesions. Unvaccinated goats exhibited the typical pathological features of active TB in humans and domestic ruminants, while vaccinated goats showed only very small lesions. The data presented in this study indicate that multi-antigenic adenoviral vectored vaccines boosts protection conferred by vaccination with BCG.
Dolphin morbillivirus (DMV) has caused 2 epizootics with high mortality rates on the Spanish Mediterranean coast, in 1990 and 2006-07, mainly affecting striped dolphins Stenella coeruleoalba. Following the first epizootic unusual DMV infections affecting only the central nervous system of striped dolphins were found, with histological features similar to subacute sclerosing panencephalitis and old dog encephalitis, the chronic latent localised infections caused by defective forms of measles virus and canine distemper virus, respectively. Between 2008 and 2010, monitoring by microscopic and immunohistochemical (IHC) studies of 118 striped dolphins stranded along Catalonia, the Valencia Region and Andalusia showed similar localised DMV nervous system infections in 25.0, 28.6 and 27.4% of cases, respectively, with no significant differences among regions or sex. The body length of DMV-infected dolphins was statistically greater than that of non-infected dolphins (196.5 vs. 160.5 cm; p < 0.001). Molecular detection of DMV was performed by 2 different RT-PCR techniques amplifying a 429 bp fragment and a 78 bp fragment both within the phosphoprotein (P) gene. The 429 bp RT-PCR results contradicted the IHC-DMV results as only 3 of 6 dolphins with positive IHC-DMV had positive PCR results. All 6 cases were positive with the 78 bp RT-PCR. These findings contraindicate the use of the 429 bp RT-PCR protocol based on the P gene to detect this specific form of DMV. DMV localised nervous infection constitutes the most relevant single cause of stranding and death in Mediterranean striped dolphins in the years following a DMV epizootic, and it might even overwhelm the effects of the epizootic itself, at least in 2007.
Caprine tuberculosis (TB) has increased in recent years, highlighting the need to address the problem the infection poses in goats. Moreover, goats may represent a cheaper alternative for testing of prototype vaccines in large ruminants and humans. With this aim, a Mycobacterium caprae infection model has been developed in goats. Eleven 6-month-old goats were infected by the endobronchial route with 1.5 × 10(3) CFU, and two other goats were kept as noninfected controls. The animals were monitored for clinical and immunological parameters throughout the experiment. After 14 weeks, the goats were euthanized, and detailed postmortem analysis of lung lesions was performed by multidetector computed tomography (MDCT) and direct observation. The respiratory lymph nodes were also evaluated and cultured for bacteriological analysis. All infected animals were positive in a single intradermal comparative cervical tuberculin (SICCT) test at 12 weeks postinfection (p.i.). Gamma interferon (IFN-?) antigen-specific responses were detected from 4 weeks p.i. until the end of the experiment. The humoral response to MPB83 was especially strong at 14 weeks p.i. (13 days after SICCT boost). All infected animals presented severe TB lesions in the lungs and associated lymph nodes. M. caprae was recovered from pulmonary lymph nodes in all inoculated goats. MDCT allowed a precise quantitative measure of TB lesions. Lesions in goats induced by M. caprae appeared to be more severe than those induced in cattle by M. bovis over a similar period of time. The present work proposes a reliable new experimental animal model for a better understanding of caprine tuberculosis and future development of vaccine trials in this and other species.
The Meyerhoff Scholarship Program (MSP) is widely recognized for its comprehensive approach of integrating students into the science community. The supports provided by the program aim to develop students, primarily Blacks, into scientists by offering them academic, social, and professional opportunities to achieve their academic and career goals. The current study allowed for a rich understanding of the perceptions of current Meyerhoff students and Meyerhoff alumni about how the program works. Three groups of MSP students were included in the study: 1) new Meyerhoff students participating in Summer Bridge (n=45), 2) currently enrolled Meyerhoff students (n=92), and 3) graduates of the MSP who were currently enrolled in STEM graduate studies or had completed an advanced STEM degree (n=19). Students described the importance of several key aspects of the Meyerhoff Scholars Program: financial support, the Summer Bridge Program, formation of Meyerhoff identity, belonging to the Meyerhoff family, and developing networks - all of which serve to integrate students both academically and socially.
Red deer (Cervus elaphus) is a widespread and abundant species susceptible to bluetongue virus (BTV) infection. Inclusion of red deer vaccination among BTV control measures should be considered. Four out of twelve BTV antibody negative deer were vaccinated against serotype 1 (BTV-1), and four against serotype 8 (BTV-8). The remaining four deer acted as unvaccinated controls. Forty-two days after vaccination (dpv), all deer were inoculated with a low cell passage of the corresponding BTV strains. Serological and virological responses were analyzed from vaccination until 28 days after inoculation (dpi). The vaccinated deer reached statistically significant (P<0.05) higher specific antibody levels than the non vaccinated deer from 34 (BTV-8) and 42 (BTV-1) dpv, maintaining stable neutralizing antibodies until 28 dpi. The non vaccinated deer remained seronegative until challenge, showing neutralizing antibodies from 7 dpi. BTV RNA was detected in the blood of the non vaccinated deer from 2 to 28 dpi, whereas no BTV RNA was found in the vaccinated deer. BTV was isolated from the blood of non vaccinated deer from 7 to 28 dpi (BTV-1) and from 9 to 11 dpi (BTV-8). BTV RNA could be identified by RT-PCR at 28 dpi in spleen and lymph nodes, but BTV could not be isolated from these samples. BT-compatible clinical signs were inapparent and no gross lesions were found at necropsy. The results obtained in the present study confirm that monovalent BTV-1 and BTV-8 vaccines are safe and effective to prevent BTV infection in red deer. This finding indicates that vaccination programs on farmed or translocated red deer could be a useful tool to control BTV.
The objective of this work was to explore whether a plasmid expressing CCL20 chemokine could improve the immune response against CSFV in co-administration with a DNA vaccine expressing the E2 protein. The immunization of pigs with the DNA vaccine formulation, that contains swine CCL20 chemokine, resulted in the homogenous induction of detectable levels of CSFV antibodies at 36 days after the first injection. Remarkably, immunized animals with E2 DNA vaccine in co-administration with the plasmid containing swine CCL20 developed high titers of neutralizing antibodies against homologous and heterologous CSFV strains and were totally protected upon a lethal viral challenge (sterilizing protection). Our results confirm the role of CCL20 to increase antibody-mediated responses. At the same time suggest the ability of CCL20 to enhance the T helper cell response associated with the induction of neutralizing antibodies against CSFV in pigs previously reported. Systemic replication of virulent CSFV in vivo during the acute phase of infection induces type I IFN. Lower average values of IFN alpha were detected in the serum of pigs immunized with pE2 and pCCL20 at 3 days after challenge. The levels of IFN-alpha detected in pigs immunized with pE2 and principally in non-vaccinated challenged animals can be related to viral load in serum at 3 and 7 days post infection and the clinical signs observed. Our results emphasized the capacity of swine CCL20 chemokine to enhance cellular, humoral and anti viral response with an adjuvant effect in the immune response elicited by E2-DNA vaccination against CSFV. To our knowledge, this is the first report demonstrating the adjuvant effect of swine CCL20 to effectively enhance the potential of DNA vaccine in the immune induction and protection against virus challenge in swine infection model.
To aid the pharmaceutical and cosmetic industry in the development of alternatives to prevent melanin-related hyperpigmentation disorders, the plant Dalea elegans was submitted to fractionation with the aim of obtaining its anti-tyrosinase principle. Bioguided fractionation of D. elegans led to the isolation of 5,2,4-trihydroxy-2?,2?-dimethylchromene-(6,7:5?,6?)-flavanone (1) as the active compound. This novel flavanone, named as dalenin, showed notable activity at inhibiting tyrosinase using l-tyrosine or l-DOPA as substrates with IC(50) values of 0.26 and 18.61 ?M, respectively. This meant that the flavanone was 52 and 495 times more effective as a monophenolase inhibitor than hydroquinone and kojic acid, respectively. With l-DOPA as a substrate, compound 1 showed itself 59 times more effective at inhibiting the enzyme than hydroquinone and showed the same level of effectiveness as that of kojic acid. It was found that the flavanone behaved as a reversible inhibitor of the enzyme and that it was a mixed-I type or a non-competitive inhibitor with l-tyrosine or l-DOPA as substrates, respectively. Molecular modeling studies were conducted confirming the inhibitory potency of dalenin and showing that the 2,4-dihydroxy substituents are important for the interaction with the enzyme. The results suggest that compound 1 has great potential to be further developed as a pharmaceutical and cosmetic agent for use in dermatological disorders associated with melanin.
We report the immunogenicity of three dendrimeric peptide vaccine candidates for classical swine fever virus (CSFV). Each dendrimeric construct contained four copies of a B-cell epitope from the E2 glycoprotein of CSFV [construct 1: E2 (694-712); 2: E2 (712-727); 3: E2 (829-842)] joined to a T-cell epitope from the NS3 protein (residues 1446-1460). Intramuscular immunization of domestic pigs with the different constructs significantly reduced the clinical score after lethal challenge with CSFV. In contrast, control pigs developed severe clinical signs of the disease. All pigs vaccinated with construct 1, containing a B-cell epitope from the E2 B-C domain, developed an antibody response that recognized not only the original dendrimeric immunogen but also its constituting E2 epitope in linear form, albeit no neutralizing antibodies were detected prior to viral challenge. Two of these pigs were partially protected, which associated with the induction of IFN-? producing cells and of neutralizing antibodies upon challenge. Interestingly, the serological response elicited by construct 1 lacked antibodies to E2 A domain, used as infection markers. The dendrimeric approach could therefore provide a basis for the development of CSFV marker (DIVA) vaccines, and contribute to a better understanding of the immune responses against CSFV.
The present study examined the immunological response of antigen presenting cells (APC) to genotype-I isolates of porcine reproductive and respiratory syndrome virus (PRRSV) infection by analysing the cytokine profile induced and evaluating the changes taking place upon infection on immunologically relevant cell markers (MHCI, MHCII, CD80/86, CD14, CD16, CD163, CD172a, SWC9). Several types of APC were infected with 39 PRRSV isolates. The results show that different isolates were able to induce different patterns of IL-10 and TNF-?. The four possible phenotypes based on the ability to induce IL-10 and/or TNF-? were observed, although different cell types seemed to have different capabilities. In addition, isolates inducing different cytokine-release profiles on APC could induce different expression of cell markers.
The increasing interest in Rift Valley fever virus (RVFV) and its potential impact on naive animal populations deserve revisiting experimental reproduction of RVFV infection, particularly in those animal breeds for which no data about their susceptibility to RVFV infection have ever been recorded. In this study we show the susceptibility of 9-10 weeks old European sheep (Ripollesa breed) to RVFV infection, showing a mild, subacute form of disease. Four different viral isolates efficiently replicated in vivo after subcutaneous experimental inoculation, and consistent viral loads in blood and virus shedding (variable in length depending on the RVFV isolate used) were detected, showing horizontal transmission to a noninfected, sentinel lamb. RVFV infection caused transient pyrexia in adult lambs and no other clinical symptoms were observed, with the exception of corneal opacity ("blue eye") found in 3 out of 16 subcutaneously inoculated sheep. In conclusion, adult sheep from this European breed are readily infected with RVFV without apparent clinical manifestations.
The recent pandemic caused by human influenza virus A(H1N1) 2009 contains ancestral gene segments from North American and Eurasian swine lineages as well as from avian and human influenza lineages. The emergence of this A(H1N1) 2009 poses a potential global threat for human health and the fact that it can infect other species, like pigs, favours a possible encounter with other influenza viruses circulating in swine herds. In Europe, H1N1, H1N2 and H3N2 subtypes of swine influenza virus currently have a high prevalence in commercial farms. To better assess the risk posed by the A(H1N1) 2009 in the actual situation of swine farms, we sought to analyze whether a previous infection with a circulating European avian-like swine A/Swine/Spain/53207/2004 (H1N1) influenza virus (hereafter referred to as SwH1N1) generated or not cross-protective immunity against a subsequent infection with the new human pandemic A/Catalonia/63/2009 (H1N1) influenza virus (hereafter referred to as pH1N1) 21 days apart. Pigs infected only with pH1N1 had mild to moderate pathological findings, consisting on broncho-interstitial pneumonia. However, pigs inoculated with SwH1N1 virus and subsequently infected with pH1N1 had very mild lung lesions, apparently attributed to the remaining lesions caused by SwH1N1 infection. These later pigs also exhibited boosted levels of specific antibodies. Finally, animals firstly infected with SwH1N1 virus and latter infected with pH1N1 exhibited undetectable viral RNA load in nasal swabs and lungs after challenge with pH1N1, indicating a cross-protective effect between both strains.
The degree of apoptosis in the livers of pigs with hepatitis due to naturally-occurring postweaning multisystemic wasting syndrome (PMWS) was evaluated semi-quantitatively by immunohistochemical detection of the apoptotic marker cleaved caspase-3 (CCasp3). The amount and distribution of porcine circovirus type 2 (PCV2) virus in the liver was evaluated using in situ hybridisation. Livers with mild, stage I hepatitis exhibited similar degrees of apoptosis to controls; those with stage II lesions had variable apoptotic rates, ranging from mild to high, and in livers with more severe, stage III hepatitis, high levels of hepatocyte apoptosis was a feature. Statistical analyses indicated a positive association between the rate of apoptosis, the severity of the hepatitis and the amount of PCV2 DNA in the liver. Double immunolabelling for CCasp3 and PCV2 DNA revealed a predominance of cells labelling only for PCV2, followed by fewer cells labelling only for CCasp3, and the least number labelling for both. The findings suggest that apoptosis, possibly triggered by PCV2 infection and/or hepatic inflammation, plays a key role in the pathogenesis of hepatitis in pigs with naturally-occurring PMWS.
A cross-sectional study was carried out to assess the prevalence and circulation of bluetongue virus (BTV) in Spanish ibexes (Capra pyrenaica hispanica). A total of 770 sera samples, 380 blood samples and 34 spleen samples were collected between 2006 and 2009 in Andalusia (southern Spain), a region and time period with a wide circulation of BTV in livestock. Thirty-one out of 770 (4.0%; CI(95%): 2.6-5.4) sera samples analyzed by ELISA showed antibodies against BTV. Twenty-four out of 31 seropositive samples were tested against BTV serotypes 1, 4 and 8 by serum neutralization test (SNT). Neutralizing antibodies against BTV-1 and BTV-4 were detected in seven and ten animals, respectively, four of them showed neutralizing antibodies to both serotypes. The animals seropositive to BTV-4 were sampled between 2006 and 2008, while BTV-1 circulation was confirmed in ibexes sampled between 2007 and 2009. None of the ibexes presented neutralizing antibodies against BTV-8. Statistically significant differences were found among regions and years, which is in coincidence with what occurred in domestic ruminants. There were no statistically significant differences between sexes, age classes and habitats (captivity vs. free-living). BTV RNA was not found in any of the 380 blood samples analyzed. However, BTV-1 RNA was detected from spleen in one Spanish ibex from Málaga province in August 2008. This finding evidences the presence of BTV-1 in Spanish ibex in a municipality where BT outbreaks were not detected in domestic ruminants during that period. Results of the present study show that Spanish ibexes were exposed and responded serologically to both BTV-1 and BTV-4. The low seroprevalence obtained suggests that Spanish ibex is not a relevant species in the dissemination of BT. However, the detection of BTV-1 RNA and the presence of seropositive ibexes in areas where BT outbreaks were not detected in livestock, could not exclude a significant role in the epidemiology of BTV in certain areas.
Practical research experience has been seen as an important tool to enhance learning in STEM fields and shape commitment to science careers. Indeed, this was a prominent recommendation of the Boyer Commission. Further, there is evidence this is especially important for minority students. In this paper, we examine the role of practical research experience during the summer for talented minority undergraduates in STEM fields. We focus on the link between summer research and STEM Ph.D. program matriculation. We examine evidence on this question using detailed data on students participating in the Meyerhoff Scholarship Program over a 14 year period at the University of Maryland Baltimore County. Our results provide evidence of strong positive effects of summer research on participation in STEM Ph.D. programs. Further, we show that the effects of summer research vary with the frequency and timing of these experiences. The evidence that educational strategies such as summer research experiences improve academic outcomes of minorities is vital, given concern about the science pipeline in the U.S. and the continuing growth in the racial/ethnic diversity of the college-age population.
Two striped dolphins (Stenella coeruleoalba) were found stranded on the Catalonian Spanish coast. The main pathologic finding in both animals was the existence of multiple granulomatous lesions in the blubber, microscopically composed of macrophages and multinucleated cells containing vacuolar material. This material was identified as ceroid pigment due to its ultrastructural morphology, autofluorescence, and positive staining with periodic acid-Schiff and Ziehl-Neelsen techniques. The special stains and electron microscopy did not reveal any microorganisms associated with the lesions. These findings are very suggestive of "nutritional panniculitis," a well-defined entity associated with vitamin E deficiency that has been rarely described in free-living species.
A transthoracic infection involving a low dose of Mycobacterium tuberculosis has been used to establish a new model of infection in minipigs. The 20-week monitoring period showed a marked Th1 response and poor humoral response for the whole infection. A detailed histopathological analysis was performed after slicing the formalin-fixed whole lungs of each animal. All lesions were recorded and classified according to their microscopic aspect, their relationship with the intralobular connective network and their degree of maturity in order to obtain a dissemination ratio (DR) between recent and old lesions. CFU counts and evolution of the DR with time showed that the proposed model correlated with a contained infection, decreasing from week 9 onwards. These findings suggest that the infection induces an initial Th1 response, which is followed by local fibrosis and encapsulation of the granulomas, thereby decreasing the onset of new lesions. Two therapeutic strategies were applied in order to understand how they could influence the model. Thus, chemotherapy with isoniazid alone helped to decrease the total number of lesions, despite the increase in DR after week 9, with similar kinetics to those of the control group, whereas addition of a therapeutic M. tuberculosis fragment-based vaccine after chemotherapy increased the Th1 and humoral responses, as well as the number of lesions, but decreased the DR. By providing a local pulmonary structure similar to that in humans, the mini-pig model highlights new aspects that could be key to a better understanding tuberculosis infection control in humans.
T-cell epitopes of porcine reproductive and respiratory syndrome virus (PRRSV) glycoproteins 4 (GP4), 5 (GP5) and nucleocapsid (N) were predicted using bioinformatics and later tested by IFN-gamma ELISPOT in pigs immunized with either a modified live vaccine (MLV) or DNA (open reading frames 4, 5 or 7). For MLV-vaccinated pigs, immunodominant epitopes were found in N but T-epitopes were also found in GP4 and GP5. For DNA-immunized pigs, some peptides were differently recognized. Using a large set of PRRSV sequences it was shown that N contains a conserved epitope and that for GP5, the genotype-I counterparts of previously reported epitopes of genotype-II strains were also immunogenic.
The objective of this study was to evaluate the prevalence of infection with porcine circovirus-2 (PCV-2) and porcine reproductive and respiratory syndrome virus (PRRSV) through a longitudinal study in an integrated swine production system (7 farms) experiencing postweaning multisystemic wasting syndrome (PMWS). Risk factors for PCV-2 infection and for PCV-2 and PRRSV coinfection were also evaluated. Fifteen sows from each herd and 4 non-cross-fostered piglets from each sow were randomly selected at farrowing and ear-tagged at birth. Serum samples were analyzed for antibodies to PCV-2 and for detection of the PCV-2 and PRRSV genomes. Statistical analyses involved 2 approaches. The 1st approach characterized the dynamics of PCV-2 infection and their relationship with PRRSV infection. The 2nd approach analyzed the probability of being infected by PCV-2 or by both PCV-2 and PRRSV through a generalized linear mixed model incorporating sow and farm characteristics. At the 1st sampling time (1 wk of age), there was a significant relationship between sow PCV-2 infection and piglet PCV-2 infection (P < 0.0001). The risk of PCV-2 and PRRSV coinfection was 1.85 times greater in piglets from a sow with low titers of PCV-2 antibodies than in piglets from sows with medium to high titers (P = 0.03) and was 2.54, 2.40, and 2.02 times greater, respectively, in piglets from primiparous sows, PCV-2-infected sows, and farms in an area of high pig density than in piglets from sows of higher parity (P = 0.004), noninfected sows (P = 0.04), and farms in a low-density area (P = 0.09).
The current study examines the outcomes, processes, and individual predictors of pursuit of a STEM PhD among African-American students in the Meyerhoff Scholarship Program. Meyerhoff students were nearly five times more likely than comparison students to pursue a STEM PhD. Program components consistently rated as important were financial scholarship, being part of the Meyerhoff Program community, the Summer Bridge program, study groups, staff academic advising, and summer research opportunities. Furthermore, focus group findings revealed student internalization of key Meyerhoff Program values, including a commitment to excellence, accountability, group success, and giving back. In terms of individual predictors, multinomial logit regression analyses revealed that Meyerhoff students with higher levels of research excitement at college entry were more likely to pursue a STEM PhD.
Most countries carrying out campaigns of bovine tuberculosis (TB) eradication impose a ban on the use of mycobacterial vaccines in cattle. However, vaccination against paratuberculosis (PTB) in goats is often allowed even when its effect on TB diagnosis has not been fully evaluated. To address this issue, goat kids previously vaccinated against PTB were experimentally infected with TB.
It has been recently reported by our group that dendrimeric constructs combining B- and T-cell epitopes from classical swine fever virus (CSFV) provided partial protection against experimental infection. This research evaluated four newly designed constructions while taking into account our previous work, including the direct implication that a T-cell epitope from the NS3 protein contributes to the generation of the immune response against CSFV. To this end, the dendrimeric constructions, including either this NS3 T-cell epitope alone or two different B-cell epitopes without this T-cell epitope, were used to immunise pigs. Thus, construct 1, containing the NS3 T-cell epitope and four copies of a previously described B-cell epitope, significantly reduced the clinical scores and RNA viral loads after challenge relative to the control group. In three out of six animals in this group, vaccination achieved partial protection and was associated with IFN-gamma producing-cells and neutralising antibodies. In contrast, the pigs immunised with construct 2, again with four copies of the B epitope of construct 1 but lacking the T-cell motif, developed more severe clinical signs. Finally, the additional constructs 3 and 4 included four copies of a B epitope that was different from the epitope used in constructs 1 and 2 with or without the abovementioned NS3 T-cell epitope, respectively. Pigs immunised with these latter constructs developed low levels of peptide-specific antibodies that correlated with equally low levels of cellular responses, an absence of neutralising antibodies and a lack of protection. Even so, the clinical scores in the first week after the challenge were less severe for animals vaccinated with construct 3 than for those given construct 4. Our results confirm the relevant role of the B-cell epitope in residues 694-712 of the glycoprotein E2 (which is used in both constructs 1 and 2) for protection against CSFV, as well as the appropriateness of the newly used NS3 peptide as a specific T-cell epitope in domestic pigs.
This is the first efficacy study using the experimental goat model, a natural host of tuberculosis (TB), to evaluate the efficacy of heterologous Mycobacterium bovis bacillus Calmette-Guérin (BCG) prime followed by boosting with a replication-deficient adenovirus expressing the antigen Ag85A (AdAg85A). Three experimental groups of 11 goat kids each were used: BCG vaccinated, BCG vaccinated and AdAg85A boosted, and nonvaccinated. Twenty-two goat kids were vaccinated with ?5 × 10(5) CFU of BCG (week 0), and 11 of them were boosted at week 8 with 10(9) PFU of AdAg85A. At week 14, all goats were challenged by the endobronchial route with ?1.5 × 10(3) CFU of Mycobacterium caprae. The animals were euthanized at week 28. Cellular and humoral immunity induced by vaccination and M. caprae infection was measured throughout the study. After challenge BCG-AdAg85A-vaccinated animals exhibited reduced pathology compared to BCG-vaccinated animals in lungs and in pulmonary lymph nodes. There were significant reductions in bacterial load in both groups of vaccinated goats, but the reduction was more pronounced in prime-boosted animals. Antigen-specific gamma interferon (IFN-?) and humoral responses were identified as prognostic biomarkers of vaccination outcome depending on their correlation with pathological and bacteriological results. As far as we know, this is the first report using multidetector computed tomography (MDCT) to measure vaccine efficacy against pulmonary TB in an animal model. The use in vaccine trials of animals that are natural hosts of TB may improve research into human TB vaccines.
Many wild ruminants such as Spanish ibex (Capra pyrenaica) are susceptible to Bluetongue virus (BTV) infection, which causes disease mainly in domestic sheep and cattle. Outbreaks involving either BTV serotypes 1 (BTV-1) and 8 (BTV-8) are currently challenging Europe. Inclusion of wildlife vaccination among BTV control measures should be considered in certain species. In the present study, four out of fifteen seronegative Spanish ibexes were immunized with a single dose of inactivated vaccine against BTV-1, four against BTV-8 and seven ibexes were non vaccinated controls. Seven ibexes (four vaccinated and three controls) were inoculated with each BTV serotype. Antibody and IFN-gamma responses were evaluated until 28 days after inoculation (dpi). The vaccinated ibexes showed significant (P<0.05) neutralizing antibody levels after vaccination compared to non vaccinated ibexes. The non vaccinated ibexes remained seronegative until challenge and showed neutralizing antibodies from 7 dpi. BTV RNA was detected in the blood of non vaccinated ibexes from 2 to the end of the study (28 dpi) and in target tissue samples obtained at necropsy (8 and 28 dpi). BTV-1 was successfully isolated on cell culture from blood and target tissues of non vaccinated ibexes. Clinical signs were unapparent and no gross lesions were found at necropsy. Our results show for the first time that Spanish ibex is susceptible and asymptomatic to BTV infection and also that a single dose of vaccine prevents viraemia against BTV-1 and BTV-8 replication.
Conventional antimicrobial strategies have become increasingly ineffective due to the emergence of multidrug resistance among pathogenic microorganisms. The need to overcome these deficiencies has triggered the exploration of alternative treatments and unconventional approaches towards controlling microbial infections. Photodynamic therapy (PDT) was originally established as an anticancer modality and is currently used in the treatment of age-related macular degeneration. The concept of photodynamic inactivation requires cell exposure to light energy, typically wavelengths in the visible region that causes the excitation of photosensitizer molecules either exogenous or endogenous, which results in the production of reactive oxygen species (ROS). ROS produce cell inactivation and death through modification of intracellular components. The versatile characteristics of PDT prompted its investigation as an anti-infective discovery platform. Advances in understanding of microbial physiology have shed light on a series of pathways, and phenotypes that serve as putative targets for antimicrobial drug discovery. Investigations of these phenotypic elements in concert with PDT have been reported focused on multidrug efflux systems, biofilms, virulence and pathogenesis determinants. In many instances the results are promising but only preliminary and require further investigation. This review discusses the different antimicrobial PDT strategies and highlights the need for highly informative and comprehensive discovery approaches.
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