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Listeria monocytogenes is one of the main foodborne pathogens worldwide. Although its response to stress conditions has been extensively studied, it is still present in the food processing environments and is a concern for consumers. To investigate how this microorganism adapts its proteome in mild stress conditions, a combined proteomics and bioinformatics approach was used to characterize the immunogenic protein profile of a sequence type 7 (ST7) strain that caused severe listeriosis outbreaks in central Italy. Extracted proteins were analyzed by immunoblotting using positive sera against L. monocytogenes and nLC-ESI-MS/MS, and all data were examined by five software to predict subcellular localization (SCL). A total of 226 proteins were extracted from the bands of interest, 58 of which were classified as potential immunogenic antigens. Compared to control cells grown under optimal conditions, six proteins, some of which under-described, were expressed under mild acid and salt stress conditions and/or at 12°C. In particular, adaptation and shaping of the proteome mainly involved cell motility at 12°C without acid and salt stress, whereas the combination of the same temperature with mild acid and salt stress induced a response concerning carbohydrate metabolism, oxidative stress, and DNA repair. Raw data are available via ProteomeXchange with identifier PXD033519.
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Listeria monocytogenes , Ácidos , Listeria monocytogenes/genética , Listeria monocytogenes/metabolismo , Proteoma/metabolismo , Estresse Salino , Espectrometria de Massas em TandemRESUMO
The genus Brucella includes several genetically monomorphic species but with different phenotypic and virulence characteristics. In this study, proteins of two Brucella species, B. melitensis type strain 16 M and B. ovis REO198 were compared by proteomics approach, in order to explain the phenotypic and pathophysiological differences among Brucella species and correlate them with virulence factors. Protein extracts from the two Brucella species were separated by SDS-PAGE and 5 areas, which resulted qualitatively and quantitatively different, were analyzed by nLC-MS/MS. A total of 880 proteins (274 proteins of B. melitensis and 606 proteins of B. ovis) were identified; their functional and structural features were analyzed by bioinformatics tools. Four unique peptides belonging to 3 proteins for B. ovis and 10 peptides derived from 7 proteins for B. melitensis were chosen for the high amount of predicted B-cell epitopes exposed to the solvent. Among these proteins, outer-membrane immunogenic protein (N8LTS7) and 25 kDa outer-membrane immunogenic protein (Q45321), respectively of B. ovis and B. melitensis, could be interesting candidates for improving diagnostics tests and vaccines. Moreover, 8 and 13 outer and periplasmic non homologue proteins of B. ovis and B. melitensis were identified to screen the phenotypic differences between the two Brucella strains. These proteins will be used to unravel pathogenesis and ameliorate current diagnostic assays.
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Brucella melitensis/patogenicidade , Brucella ovis/patogenicidade , Biologia Computacional/métodos , Proteômica/métodos , Fatores de Virulência/metabolismo , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/metabolismo , Brucella melitensis/imunologia , Brucella melitensis/metabolismo , Brucella ovis/imunologia , Brucella ovis/metabolismo , Cromatografia Líquida , Epitopos de Linfócito B/análise , Nanotecnologia , Espectrometria de Massas em Tandem , Fatores de Virulência/imunologiaRESUMO
In this study, a new and alternative method based on monoclonal antibodies (MAbs) for the rapid detection of Yersinia enterocolitica O:8 was developed. This microorganism is an emerging foodborne pathogen causing gastrointestinal disease in humans. The transmission can occur through contaminated food such as raw or undercooked meat, milk and dairy products, water and fresh vegetables. Nine MAbs (46F7, 54B11, 54C11, 62D10, 64C7, 64C10, 72E8, 72E10, 72G6) were characterized and selected versus Y. enterocolitica O:8, and only 2 of them showed also a weak cross-reaction with Campylobacter jejuni. The MAb 54B11 was used for the development of Y. enterocolitica capture-ELISA in food matrices, i.e. meat and dairy products (nâ¯=â¯132). The method was validated by ISO 16140:2003 and compared with the official method for the detection of presumptive pathogenic Y. enterocolitica (ISO 10273:2003). Relative accuracy, sensitivity and specificity corresponded to 100%. The selectivity was evaluated on other food samples (nâ¯=â¯126) showing a lower confidence limit of 90.3% and an upper confidence limit of 100%. The results from this study demonstrated that the developed method was rapid and cheap, specific and sensitive for the screening of the pathogen in food.
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Ensaio de Imunoadsorção Enzimática/métodos , Microbiologia de Alimentos/métodos , Carne/microbiologia , Leite/microbiologia , Verduras/microbiologia , Yersinia enterocolitica/isolamento & purificação , Animais , Ensaio de Imunoadsorção Enzimática/economia , Contaminação de Alimentos/análise , Microbiologia de Alimentos/economia , Sorogrupo , Yersinia enterocolitica/genética , Yersinia enterocolitica/crescimento & desenvolvimentoRESUMO
Monoclonal antibodies (MAbs) against horse IgG were produced by immunizing Balb/c mice with purified horse IgG and were characterized in indirect ELISA versus purified immunoglobulins from donkey, cow, buffalo, sheep, pig, and chicken. Three MAbs (1B10B6C9, 1B10B6C10, 1B10B6E9) reacted only with horse and donkey IgG and IgM and, in western blotting, were specific for the Fc fragment of equine IgG. MAb 1B10B6E9 was used in chemiluminescent immunoblotting assay for the diagnosis of dourine and in indirect immunofluorescence assay (IFA) for the diagnosis of African horse sickness and dourine.
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Doença Equina Africana/sangue , Doença Equina Africana/diagnóstico , Anticorpos Monoclonais Murinos/química , Mal do Coito (Veterinária)/sangue , Mal do Coito (Veterinária)/diagnóstico , Imunoglobulina G/sangue , Doença Equina Africana/imunologia , Animais , Anticorpos Monoclonais Murinos/imunologia , Mal do Coito (Veterinária)/imunologia , Técnica Indireta de Fluorescência para Anticorpo/métodos , Cavalos , Imunoglobulina G/imunologia , CamundongosRESUMO
The significance of Trypanosoma equiperdum as the causative agent of dourine cannot be understated, especially given its high mortality rate among equids. International movement of equids should be subject to thorough health checks and screenings to ensure that animals are not infected with Trypanosoma equiperdum. This involves the implementation of quarantine protocols, testing procedures, and the issuance of health certificates to certify the health status of the animals. Three proteins, the peptidyl-prolyl cis-trans isomerase (A0A1G4I8N3), the GrpE protein homolog (A0A1G4I464) and the transport protein particle (TRAPP) component, putative (A0A1G4I740) (UniProt accession numbers SCU68469.1, SCU66661.1 and SCU67727.1), were identified as unique to T. equiperdum by bioinformatics analysis. The proteins were expressed as recombinant proteins and tested using an indirect ELISA and immunoblotting test with a panel of horse positive and negative sera for dourine. The diagnostic sensitivity, specificity and accuracy of the i-ELISAs were 86.7%, 53.8% and 59.0% for A0A1G4I8N3; 53.3%, 58.7% and 57.9% for A0A1G4I464; and 73.3%, 65.0% and 66.3% for A0A1G4I740, respectively, while the diagnostic sensitivity, specificity and accuracy of immunoblotting were 86.7%, 92.5% and 91.6% for A0A1G4I8N3; 46.7%, 81.3% and 75.8% for A0A1G4I464; and 80.0%, 63.8% and 66.3% for A0A1G4I740. Among the three proteins evaluated in the present work, A0A1G4I8N3 provided the best results when tested by immunoblotting; diagnostic application of this protein should be further investigated using a greater number of positive and negative sera.
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PURPOSE: Brucella canis is pathogenic for dogs and humans. Serological diagnosis is a cost-effective approach for disease surveillance, but a major drawback of current serological tests is the cross-reactivity with other bacteria that results in false positive reactions. Development of indirect tests with improved sensitivity and specificity that use selected B. canis proteins instead of the whole antigen remain a priority. EXPERIMENTAL DESIGN: A western blotting assay was developed to define the serum antibody patterns associated to infection using a panel of positive and negative dog sera. B. canis positive sera recognized immunogenic bands ranging from 7 to 30 kDa that were then submitted to ESI-LC-MS/MS and analyzed by bioinformatics tools. RESULTS: A total of 398 B. canis proteins were identified. Bioinformatics tools identified 16 non cytoplasmic immunogenic proteins predicted as non-homologous with the most important Brucella cross-reactive bacteria and nine B. canis proteins non-homologous to B. ovis; among the latter, one resulted non-homologous to B. melitensis. Data are available via ProteomeXchange with identifier PXD042682. CONCLUSIONS AND CLINICAL RELEVANCE: The western blotting test developed was able to distinguish between infected and non-infected animals and may serve as a confirmatory test for the serological diagnosis of B. canis. The mass spectrometry and in silico results lead to the identification of specific candidate antigens that pave the way for the development of more accurate indirect diagnostic tests.
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Brucelose , Proteômica , Animais , Cães , Anticorpos Antibacterianos , Antígenos de Bactérias/análise , Brucelose/diagnóstico , Brucelose/veterinária , Brucelose/microbiologia , Cromatografia Líquida , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/veterinária , Espectrometria de Massas em TandemRESUMO
Bluetongue virus (BTV) is the etiologic agent of bluetongue (BT), a viral WOAH-listed disease affecting wild and domestic ruminants, primarily sheep. The outermost capsid protein VP2, encoded by S2, is the virion's most variable protein, and the ability of reference sera to neutralize an isolate has so far dictated the differentiation of 24 classical BTV serotypes. Since 2008, additional novel BTV serotypes, often referred to as "atypical" BTVs, have been documented and, currently, the full list includes 36 putative serotypes. In March 2015, a novel atypical BTV strain was detected in the blood of asymptomatic goats in Sardinia (Italy) and named BTV-X ITL2015. The strain re-emerged in the same region in 2021 (BTV-X ITL2021). In this study, we investigated the pathogenicity and kinetics of infection of BTV-X ITL2021 following subcutaneous and intravenous infection of small ruminants. We demonstrated that, in our experimental settings, BTV-X ITL2021 induced a long-lasting viraemia only when administered by the intravenous route in goats, though the animals remained healthy and, apparently, did not develop a neutralizing immune response. Sheep were shown to be refractory to the infection by either route. Our findings suggest a restricted host tropism of BTV-X and point out goats as reservoirs for this virus in the field.
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Vírus Bluetongue , Cabras , Animais , Ovinos , Vírus Bluetongue/fisiologia , Imunidade Humoral , Tropismo Viral , Ruminantes , SorogrupoRESUMO
Canine brucellosis caused by Brucella canis, is an infectious disease affecting dogs and wild Canidae. Clinical diagnosis is challenging, and laboratory testing is crucial for a definitive diagnosis. Various serological methods have been described, but their accuracy is uncertain due to limited validation studies. The present study aimed to evaluate the performances of three serological tests for the diagnosis of B. canis in comparison with bacterial isolation (gold standard), in order to establish a protocol for the serological diagnosis of canine brucellosis. A panel of sera from naturally infected dogs (n = 61), from which B. canis was isolated, and uninfected dogs (n = 143), negative for B. canis isolation, were tested using microplate serum agglutination (mSAT), complement fixation performed using the Brucella ovis antigen (B. ovis-CFT), and a commercial immunofluorescence assay (IFAT). The sensitivity and specificity of the three serological methods were, respectively, the following: 96.7% (95% CI 88.8-98.7%) and 92.3 (95% CI 86.7-95.1%) for mSAT; 96.7% (95% CI 88.8-98.7%) and 96.5 (95% CI 92.1-98.2%) for B. ovis-CFT; 98.4% (95% CI 91.3-99.4%) and 99.3 (95% CI 96.2-99.8%) for IFAT. The use in of the three methods in parallel, combined with bacterial isolation and molecular methods, could improve the diagnosis of the infection in dogs.
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Brucella RB51 is a live modified vaccine. Its use in water buffalo has been proposed using a vaccination protocol different to that used for cattle, but knowledge of the long-term effects of RB51 vaccination in this species remains incomplete. The aim of the study was to evaluate the safety and kinetics of antibody responses in water buffaloes vaccinated according to the protocol described for the bovine species in the WOAH Manual, modified with the use of a triple dose. Water buffaloes were vaccinated with the vaccine RB51. A booster vaccination was administered at 12 months of age. When turning 23-25 months old, female animals were induced to pregnancy. RB51-specific antibodies were detected and quantified using a CFT based on the RB51 antigen. Vaccinated animals showed a positive serological reaction following each vaccine injection, but titers and the duration of the antibody differed among animals. For 36 weeks after booster vaccination, the comparison of CFT values between vaccinated and control groups remained constantly significant. Afterwards, antibody titers decreased. No relevant changes in antibody response were recorded during pregnancy or lactation. In conclusion, results indicated that the vaccination schedule applied is safe and allows for vaccinated and unvaccinated controls to be discriminated between for up to 8 months after booster vaccination.
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Epizootic hemorrhagic disease virus serotype 8 (EHDV-8) emerged in Europe for the first time in late 2022. In this study, we investigated the kinetics of EHDV-8 infection in cattle, sheep, and goats. Following experimental infection with EHDV-8, four out of five calves displayed fever, while another calf exhibited ulcerative and crusty lesions of the muzzle. RNAemia peaked at day 7 post infection in all calves and remained relatively stable till the end of the study, at 78 days post infection. Infectious virus was isolated up to 21 days post infection in one calf. As far as small ruminants are concerned, one sheep experienced fever and two out of five had consistent RNAemia that lasted until the end of the study. Remarkably, infectious virus was evidenced at day 7 post infection in one sheep. In goats, no RNA was observed. All infected animals seroconverted, and a neutralizing immune response was observed in all species, with calves exhibiting a more robust response than sheep and goats. Our study provides insights into the kinetics of EHDV-8 infection and the host immune responses. We also highlight that sheep may also play a role in EHDV-8 epidemiology. Altogether, the data gathered in this study could have important implications for disease control and prevention strategies, providing crucial information to policy makers to mitigate the impact of this viral disease on livestock.
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Doenças dos Bovinos , Doenças das Cabras , Vírus da Doença Hemorrágica Epizoótica , Infecções por Reoviridae , Doenças dos Ovinos , Ovinos , Bovinos , Animais , Infecções por Reoviridae/veterinária , Cabras , Sorogrupo , Doenças dos Bovinos/epidemiologia , RuminantesRESUMO
Monoclonal antibodies (MAbs) against epizootic hemorrhagic disease virus (EHDV) were produced by immunizing BALB/c mice with rec-VP7-EHDV2; 66 clones producing MAbs able to recognize the VP7-EHDV with a strong reaction were obtained and tested in indirect enzyme-linked immunosorbent assay (i-ELISA) against the whole epizootic hemorrhagic disease (EHD) virus serotype 2; potential cross-reactions with related orbiviruses, as Bluetongue virus (BTV) and African horse sickness virus (AHSV), were investigated as well by i-ELISA, Western blot, and immunofluorescence. Fifty-three MAbs were specific for EHDV (VP7 recombinant protein and whole virus) and 13 reacted also with the VP7 of BTV. None of the MAbs reacted with AHSV. MAbs specific for EHDV were further characterized in a competitive ELISA (c-ELISA): 20 among them were found useful to develop a c-ELISA for the detection of antibodies against EHDV in bovine sera. The availability of this extensive set of MAbs provides the opportunity to develop a c-ELISA for the serological diagnosis of EHDV and to tune new methods for the isolation and identification of the virus in biological samples and cell cultures. The experimentation protocol was approved by the Italian Ministry of Health (number 639/2018-PR, Resp. to Prot. BDF16.13#295833199#).
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Vírus Bluetongue , Vírus da Doença Hemorrágica Epizoótica , Animais , Anticorpos Monoclonais , Anticorpos Antivirais , Western Blotting , Bovinos , Ensaio de Imunoadsorção Enzimática , CamundongosRESUMO
Mycoplasma mycoides subsp. mycoides (Mmm) is the etiological agent of contagious bovine pleuropneumonia (CBPP), one of the major diseases affecting cattle in sub-Saharan Africa. Some evidences suggest that the immune system of the host (cattle) plays an important role in the pathogenic mechanism of CBPP, but the factors involved in the process remain largely unknown. The present study aimed to investigate the cell response of bovine polymorphonuclear neutrophils (PMNs) after Mmm in vitro exposure using one step RT-qPCR and Western blotting. Data obtained indicate that gene and protein expression levels of some pro-inflammatory factors already change upon 30 min of PMNs exposure to Mmm. Of note, mRNA expression level in Mmm exposed PMNs increased in a time-dependent manner and for all time points investigated; targets expression was also detected by Western blotting in Mmm exposed PMNs only. These data demonstrate that when bovine PMN cells are triggered by Mmm, they undergo molecular changes, upregulating mRNA and protein expression of specific pro-inflammatory factors. These results provide additional information on host-pathogen interaction during CBPP infection.
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Trypanosoma equiperdum is the causative agent of dourine, a parasitic venereal disease of equids. In this work, rabbits were infected with T. equiperdum strain OVI; serological tests (complement fixation test, ELISA and immunoblotting), used for the diagnosis of dourine in horses, were applied to study rabbit humoral immune response and to characterise T. equiperdum antigen pattern recognised by antibodies from infected rabbits. Moreover a protein extract of T. equiperdum strain OVI was produced and tested in skin tests on infected rabbits to detect the cell-mediated response induced by T. equiperdum, in order to evaluate its use in the field diagnosis of dourine. Sera of infected rabbits recognized in immunoblotting Trypanosoma protein bands with molecular weight below 37 kDa, providing a serological response comparable with that already observed in dourine infected horses. Moreover the trypanosome protein extract was capable to produce in vivo delayed-type hypersensitivity (DHT Type IV) in rabbits and proved itself to be non-toxic and non-sensitizing.
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Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/imunologia , Hipersensibilidade Tardia/imunologia , Imunidade Humoral/imunologia , Trypanosoma/imunologia , Tripanossomíase/diagnóstico , Animais , Feminino , Cobaias , Hipersensibilidade Tardia/parasitologia , Masculino , Coelhos , Testes Cutâneos , Tripanossomíase/imunologia , Tripanossomíase/parasitologiaRESUMO
The acceptance of serology data instead of challenge for market release of new batches of commercial vaccine is under evaluation by regulatory agencies in order to reduce the use of animals and costs for manufacturers. In this study two vaccines for Bluetongue virus serotype 8 were submitted to quality controls required by the European Pharmacopoeia and tested on sheep in comparison with a commercial inactivated vaccine. Body temperature, antibody titres and viraemia of vaccinated and controls sheep were recorded. In addition IL4 and IFNγ in sera and supernatant derived from in vitro stimulation of blood cells were also quantified using two commercial ELISA kit. The outer-capsid protein VP2 contained in vaccine formulations was quantified using a home-made capture-ELISA. Results obtained indicates that in-lab evaluation of cell-mediated and humoral immune response are useful parameters to predict the efficacy of BTV inactivated vaccines avoiding the challenge phase required to release new batches of vaccines with proven clinical efficacy and safety. The correlation observed between serology data and VP2 protein concentration of final product could be useful in-process control to predict if a new vaccine batch of BTV must be discarded or released to the market.
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Alternativas aos Testes com Animais/métodos , Vírus Bluetongue/imunologia , Bluetongue/prevenção & controle , Doenças dos Ovinos/prevenção & controle , Vacinas Virais/farmacologia , Animais , Controle de Qualidade , Ovinos , Carneiro Doméstico , Vacinas de Produtos Inativados/farmacologiaRESUMO
Monoclonal antibodies (MAbs) against AHSV were produced by immunising BALB/c mice with AHSV serotype 9 and six clones able to recognize specifically the VP7-AHSV with a strong reactivity were selected. The specificity of the MAbs was assessed in i-ELISA against a commercial VP7-AHSV and in immunoblot against a home-made VP7-AHSV, expressed by a Baculovirus expression system; potential cross-reactions with related orbiviruses (Bluetongue virus and Epizootic Haemorrhagic Disease virus) were investigated as well. One of the six MAbs selected, MAb 7F11E14, was tested in direct immunofluorescence and reacted with all nine AHSV serotypes, but didn't cross-react with BTV and EHDV. MAb 7F11E14 was also used to develop a competitive ELISA and was able to detect AHSV antibodies in the sera of AHS infected animals.
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Vírus da Doença Equina Africana/imunologia , Doença Equina Africana/diagnóstico , Doença Equina Africana/imunologia , Anticorpos Monoclonais/sangue , Proteínas do Core Viral/imunologia , Animais , Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Vírus Bluetongue/imunologia , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Feminino , Vírus da Doença Hemorrágica Epizoótica/imunologia , Cavalos , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Recombinantes , Sensibilidade e Especificidade , Proteínas do Core Viral/isolamento & purificaçãoRESUMO
Bacteria of the genus Brucella cause brucellosis, an infectious disease common to humans as well as to terrestrial and aquatic mammals. Since 1994 several cases of Brucella spp. infection have been reported in marine mammals worldwide. While sero-epidemiological data suggest that Brucella spp. infection is widespread globally, detecting Brucella spp.-associated antigens by immunohistochemistry (IHC) in tissues from infected animals is often troublesome. The present study was aimed at investigating, by means of IHC based upon the utilization of an anti-Brucella LPS monoclonal antibody (MAb), the central nervous system (CNS) immunoreactivity shown by B. ceti-infected, neurobrucellosis-affected striped dolphins. The aforementioned MAb, previously characterized by means of ELISA and Western Blotting techniques, was able to immunohistochemically detect smooth brucellae both within the CNS from B. ceti-infected striped dolphins and within a range of tissues from Brucella spp.-infected domestic ruminants. In conclusion, the results of the present study are of relevance both from the B. ceti infection's diagnostic and pathogenetic standpoints.
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Encefalopatias/veterinária , Brucella/isolamento & purificação , Brucelose/patologia , Sistema Nervoso Central/patologia , Stenella , Animais , Encefalopatias/microbiologia , Encefalopatias/patologia , Brucelose/microbiologia , Sistema Nervoso Central/microbiologia , Imuno-Histoquímica , EspanhaRESUMO
Dourine is a parasitic venereal disease of equines caused by T. equiperdum. Humoral antibodies are found in infected animals, but diagnosis of dourine must include history, clinical, and pathological findings in addition to serology. Complement Fixation Test (CFT) is the Office International des Epizooties (OIE) recommended test for international trade; however, some uninfected equines may give inconsistent or nonspecific reactions in CFT due to the anticomplementary effects of their sera. In this study an Indirect Enzyme Linked Immunosorbent Assay (iELISA) was developed. This test could be used to confirm positive serological cases of dourine or to solve inconclusive results obtained by CFT, in addition to Indirect Fluorescent Antibody Test (IFAT) and a Chemiluminescent Immunoblotting Assay (cIB). Six-hundred-and-six CFT negative sera and 140 sera positive to CFT and IFAT were tested by iELISA using OVI T. equiperdum as antigen. Results were expressed as percentage of positivity and the optimum cut-off value determined sensitivity and specificity of 100%. All positive sera, tested by cIB, were confirmed as positive. Additionally, twenty seven sera, low-positive at CFT and negative by IFAT, were tested with iELISA and cIB. All samples resulted negative by cIB and one of them was positive in ELISA. Our results suggest that iELISA and cIB may be used as alternative or supplementary confirmatory tests whenever other recommended serological methods are inconclusive or doubtful.
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Mal do Coito (Veterinária)/diagnóstico , Ensaio de Imunoadsorção Enzimática/veterinária , Doenças dos Cavalos/diagnóstico , Trypanosoma/isolamento & purificação , Animais , Mal do Coito (Veterinária)/parasitologia , Ensaio de Imunoadsorção Enzimática/métodos , Doenças dos Cavalos/parasitologia , CavalosRESUMO
The diagnosis of dourine can be difficult because the clinical signs of this disease in horses are similar to those of surra, caused by Trypanosoma evansi. Moreover, T. equiperdum and T. evansi are closely related and, so far, they cannot be distinguished using serological tests. In a previous work, the T. equiperdum protein pattern recognized by antibodies from dourine-infected horses and the humoral immune response kinetics were investigated by immunoblotting assay; a total of 20 sera from naturally and experimentally infected horses and from healthy animals were tested. Immunoblotting analysis showed that antibodies from infected horses specifically bind T. equiperdum low molecular weight proteins (from 16 to 35 kDa), which are not recognized by antibodies from uninfected horses. In this work, we tested other 615 sera (7 from naturally infected horses and 608 sera from healthy horses and donkeys): results confirmed the data obtained previously. In addition, six SDS-PAGE bands with molecular weight ranging from 10 to 37 kDa were analyzed by mass spectrometry, in order to identify immunogenic proteins that could be used as biomarkers for the diagnosis of dourine. A total of 167 proteins were identified. Among them, 37 were found unique for T. equiperdum. Twenty-four of them could represent possible candidate diagnostic antigens for the development of serological tests specific for T. equiperdum.
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Monoclonal antibodies (MAbs) specific for the lipopolysaccharide (LPS) of Escherichia coli O104:H4 were produced by fusion of Sp2/O-Ag-14 mouse myeloma cells with spleen cells of Balb/c mice, immunized with heat-inactivated and sonicated E. coli O104:H4 bacterial cells. Four MAbs specific for the E. coli O104:H4 LPS (1E6G6, 1F4C9, 3G6G7, and 4G10D2) were characterized and evaluated for the use in a method for the detection of E. coli O104:H4 in milk samples that involves antibody conjugation to magnetic microbeads to reduce time and increase the efficiency of isolation. MAb 1E6G6 was selected and coupled to microbeads, then used for immuno-magnetic separation (IMS); the efficiency of the IMS method for E. coli O104:H4 isolation from milk was evaluated and compared to that of the EU RL VTEC conventional culture-based isolation procedure. Milk suspensions also containing other pathogenic bacteria that could potentially be found in milk (Campylobacter jejuni, Listeria monocytogenes, and Staphylococcus aureus) were also tested to evaluate the specificity of MAb-coated beads. Beads coated with MAb 1E6G6 showed a good ability to capture the E. coli O104:H4, even in milk samples contaminated with other bacteria, with a higher number of E. coli O104:H4 CFU reisolated in comparison with the official method (121 and 41 CFU, respectively, at 10(3) E. coli O104:H4 initial load; 19 and 6 CFU, respectively, at 10(2) E. coli O104:H4 initial load; 1 and 0 CFU, respectively, at 10(1) E. coli O104:H4 initial load). The specificity was 100%.
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An immunohistochemical (IHC) technique was optimised using a monoclonal antibody (MAb) to detect Mycoplasma mycoides subsp. mycoides (Mmm), the agent of Contagious Bovine Pleuropneumonia (CBPP), in sections of lung tissue. A panel of MAbs was produced and screened for Mmm speci city and for cross-reactivity against other mycoplasmas belonging and not belonging to the Mycoplasma mycoides cluster, using in parallel indirect ELISA (i-ELISA) and Immunoblotting (IB). Based on i-ELISA and IB characterization data, 1 MAb (clone 3G10E7) was selected and its highest a nity vs Mmm was con rmed by the Quartz Crystal Microbalance (QCM) technology. Afterwards, IHC analyses were conducted to compare MAb 3G10E7 vs rabbit Mmm speci c hyperimmune serum using lung tissue sections of CBPP infected and CBPP negative animals. Results suggest that screening of MAbs using in parallel ELISA, IB, and QCM technology enables to select high a nity target speci c MAbs. Immunohistochemical results demonstrated that MAb 3G10E7 improved IHC performances, showing reduced background staining and no cross-reactivity against Mycoplasma bovis, which is responsible of pneumonia in cattle.