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1.
Comp Immunol Microbiol Infect Dis ; 104: 102092, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37992537

RESUMO

Leptospirosis is a serious health problem in tropical areas; thus, animals shed leptospires in the environment. Humans are accidental hosts infected through exposure to contaminating bacteria in the environment. One health strategy can be applied to protect and eliminate leptospirosis because this cooperates and coordinates activities between doctors, veterinarians, and ecologists. However, conventional methods still have limitations. Therefore, the main challenges of leptospirosis control are the high sensing of detection methods to screen and control the pathogens. Interestingly, nano sensing combined with a leptospirosis detection approach can increase the sensitivity and eliminate some limitations. This article reviews nanomaterial development for an advanced leptospirosis detection method, e.g., latex beads-based agglutination test, magnetic nanoparticles enrichment, and gold-nanoparticles-based immunochromatographic assay. Thus, nanomaterials can be functionalized with biomolecules or sensing molecules utilized in various mechanisms such as biosensors. Over the last decade, many biosensors have been developed for Leptospira spp. pathogen and others. The evolution of biosensors for leptospirosis detection was designed for high efficiency and might be an alternative tool. In addition, the high-sensing fabrications are useful for leptospires screening in very low levels, for example, soil or water from the environment.


Assuntos
Leptospira , Leptospirose , Nanopartículas , Humanos , Animais , Leptospirose/diagnóstico , Leptospirose/prevenção & controle , Leptospirose/microbiologia , Leptospirose/veterinária , Testes de Fixação do Látex/veterinária
2.
J Immunol Methods ; 496: 113085, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34157319

RESUMO

The chemical coupling of a protoplasmatic antigen from Mycobacterium avium subsp. paratubeculosis onto core-shell carboxylated particles was investigated with the aim of producing latex-protein complexes to be used in immunoagglutination assays capable of detecting bovine paratuberculosis disease. For this purpose, sensitizations were carried out using both colored and not colored carboxylated latexes as well as the protoplasmatic antigen at pH close to its isoelectric point to favor the antigenic protein to approach the particle surface. In all cases, higher fractions of proteins were chemically-bound to carboxyl groups on the surface of the particles. The assessment of the performance of the visual immunoagglutination assays consisted of evaluating 111 sera from healthy and infected bovines with Mycobacterium avium subsp. paratuberculosis. Complexes obtained from the colored latex allowed an acceptable visual discrimination between the studied positive and negative sera. Most of the positive samples showed strong to very strong agglutination and only a few samples reacted weakly, i.e. a sensitivity of 70%. The specificity of the assay, on the other hand, was 86%. Therefore, this rapid detection technique allows an easy and inexpensive identification of animals possibly infected with paratuberculosis "in situ" in the herds.


Assuntos
Antígenos de Bactérias/imunologia , Testes de Fixação do Látex/veterinária , Látex/química , Mycobacterium avium subsp. paratuberculosis/imunologia , Paratuberculose/diagnóstico , Animais , Estudos de Casos e Controles , Bovinos , Cor , Microesferas , Paratuberculose/imunologia , Paratuberculose/microbiologia , Valor Preditivo dos Testes , Fatores de Tempo , Fluxo de Trabalho
3.
Arq. bras. med. vet. zootec. (Online) ; 73(2): 529-533, Mar.-Apr. 2021. tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1248949

RESUMO

O presente estudo foi realizado para determinar a prevalência geral de toxoplasmose em pavões de plumagem diferente e seu efeito nas enzimas de teste da função hepática dos hospedeiros. Um total de cem pavões de plumas diferenciais, como ombro preto (n = 52), azul (n = 28), branco (n = 10) e arlequim (n = 10) foram estudados no zoológico de Bahawalpur, no Paquistão, usando o Latex Agglutination Test (LAT) e ensaio imunossorvente ligado a enzima (ELISA). A prevalência geral por LAT e ELISA foi de 37% e 30%, respectivamente. Por LAT, observou-se uma prevalência não significativamente maior (P≥0,05) em gênero (37,77%) nos machos do que nas fêmeas (36,36%), enquanto os adultos apresentaram uma prevalência maior (37,97%) em relação aos jovens (33,33%). De acordo com o ELISA, uma prevalência significativamente (P <0,05) maior (35,55%) foi observada nos machos do que nas fêmeas (25,45%) e significativamente (P <0,05) maior prevalência (31,64%) foi registrada nos adultos do que nos jovens (23,80%). A análise do perfil bioquímico sérico mostrou que o nível de bilirrubina não teve elevação significativa nos hospedeiros infectados, em comparação aos não infectados, enquanto a concentração de albumina, alanina aminotransferase (ALT), aspartato aminotransferase (AST), fosfatase alcalina (ALP) foi significativamente (P <0,05) diferente nos hospedeiros infectados. Conclui-se que a toxoplasmose afeta as enzimas do teste da função hepática. Essa é uma pesquisa preliminar e requer mais pesquisas em todo o país, com populações e amostras maiores.(AU)


Assuntos
Animais , Toxoplasma/isolamento & purificação , Toxoplasmose Animal/epidemiologia , Galliformes/microbiologia , Ensaio de Imunoadsorção Enzimática/veterinária , Testes de Fixação do Látex/veterinária , Testes de Função Hepática/veterinária
4.
Lett Appl Microbiol ; 72(6): 730-740, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33590504

RESUMO

Leptospirosis is a re-emerging zoonotic disease of animals and humans caused by pathogenic Leptospira, which has major public health concerns. The study is aimed to express the recombinant outer membrane protein (OMP) A-like protein (rLoa22) and transmembrane (rOmpL37) protein of Leptospira interrogans serovar Hardjo in the Escherichia coli and their evaluation as a diagnostic antigen in the latex agglutination test (LAT) to detect anti-leptospiral antibodies in the sera of animals. The Loa22 and OmpL37 genes lacking signal peptide coding sequences were individually amplified (522 and 963 bp), by polymerase chain reaction, and directionally cloned into a pETite N-His Kan vector for expression. The expressed purified proteins were characterized by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and immunoblot, which confirmed leptospiral specific reactive protein with a molecular weight of ~19 and 36 kDa, respectively. The sensitized latex beads coated with these OM proteins separately were evaluated in LAT using cattle sera of microscopic agglutination test (MAT) confirmed positive (n = 53) and negative (n = 52) cases of leptospirosis. The rLoa22 LAT and rOmpL37 LAT revealed the relative diagnostic sensitivity of 94·34 and 96·23%, diagnostic specificity of 92·31 and 96·15% and accuracy of 93·33 and 96·19%, with the excellent agreement of Cohen's kappa value of 0·87 and 0·92, respectively. After extensive evaluation, this rapid recombinant protein-based field diagnostic test can be applied as a screening test for the detection of anti-leptospiral antibodies in the sera of animals in the field conditions.


Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Testes de Fixação do Látex/veterinária , Leptospirose/diagnóstico , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Antiprotozoários/imunologia , Antígenos de Bactérias/genética , Bovinos , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/parasitologia , Eletroforese em Gel de Poliacrilamida , Immunoblotting , Testes de Fixação do Látex/métodos , Leptospira interrogans/imunologia , Leptospira interrogans/isolamento & purificação , Leptospirose/veterinária , Proteínas Recombinantes/genética , Testes Sorológicos/métodos , Zoonoses/diagnóstico , Zoonoses/parasitologia
5.
J Vet Med Sci ; 83(2): 329-332, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33390361

RESUMO

This study established the precision and accuracy of a modified latex agglutination turbidimetric immunoassay (LATIA) reagent, and evaluated the ability of the measurement of serum amyloid A (SAA) compared to haptoglobin and α1-acid glycoprotein, which are acute phase proteins (APPs), for diagnosis of clinical mastitis. Concentrations of APPs in cows with mastitis were significantly higher than those in healthy cow. Only the plasma SAA concentration in cows with clinical mastitis (44.90 mg/l; n=15) was significantly higher than that in those with subclinical mastitis (10.70 mg/l; n=16), enabling their diagnosis in contrast to other APPs. Thus, the SAA assay using a LATIA reagent is useful in assessing mastitis severity due to its higher sensitivity and specificity than other APP assays.


Assuntos
Doenças dos Bovinos , Mastite Bovina , Animais , Bovinos , Feminino , Haptoglobinas , Imunoturbidimetria/veterinária , Testes de Fixação do Látex/veterinária , Mastite Bovina/diagnóstico , Leite , Orosomucoide , Proteína Amiloide A Sérica
6.
Med Mycol ; 58(1): 39-46, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31220311

RESUMO

Although the point-of-care cryptococcal antigen lateral flow assay (LFA) has revolutionized the diagnosis of cryptococcosis in human patients, to date there has been no large-scale examination of this test in animals. We therefore assessed the LFA in cats, dogs and koalas suspected of having cryptococcosis. In sum, 528 serum specimens (129 from cats, 108 from dogs, 291 from koalas) were tested using the LFA and one of two commercially available latex cryptococcal antigen agglutination test (LCAT) kits. The LCAT is a proven and well-accepted method in veterinary patients and therefore taken as the "gold standard" against which the LFA was compared. The LFA achieved a sensitivity of 92%, 100%, and 98% in cats, dogs, and koalas, respectively, with corresponding negative predictive values of 94%, 100%, and 98%. The specificity of the LFA was 81%, 84%, and 62% for cats, dogs, and koalas, respectively, with corresponding positive predictive values of 76%, 48%, and 69%. These findings suggest the most appropriate role for the LFA is as a screening test to rule out a diagnosis of cryptococcosis in cats, dogs, and koalas. Point-of-care accessibility makes it equally suited for use in the field and as a cage-side test in veterinary hospitals. The suboptimal specificity of the LFA makes it less suited to definitive confirmation of cryptococcosis in animals; therefore, all LFA-positive test results should be confirmed by LCAT testing. The discrepancy between these observations and the high specificity of the LFA in humans may reflect differences in the host-pathogen interactions amongst the species.


Assuntos
Doenças do Gato/diagnóstico , Cromatografia de Afinidade/veterinária , Criptococose/veterinária , Doenças do Cão/diagnóstico , Testes de Fixação do Látex/veterinária , Phascolarctidae/microbiologia , Animais , Antígenos de Fungos/sangue , Doenças do Gato/sangue , Doenças do Gato/microbiologia , Gatos , Criptococose/sangue , Criptococose/diagnóstico , Cryptococcus , Doenças do Cão/sangue , Doenças do Cão/microbiologia , Cães , Masculino , Sistemas Automatizados de Assistência Junto ao Leito , Valor Preditivo dos Testes , Fitas Reagentes , Sensibilidade e Especificidade
7.
J Vet Med Sci ; 82(2): 229-231, 2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-31875600

RESUMO

Prevalence of antibodies to Toxoplasm gondii was studied using the latex agglutination (LA) method, followed by sucrose density gradient centrifugation (SDGC) method on the small Indian mongoose (Herpestes auropunctatus), which inhabits Amami-Oshima Island. Of the 362 samples, 38 (10.5%) revealed positive. Single or double peaks in the 7-8 and/or 12-14 fraction to LA titer by SDGC indicated the early stage of T. gondii infection. It is suggested that domestic/feral cats play an important role for spreading this zoonotic pathogen to the mongoose as well as other species that are endemic to this island. Future studies are warranted to prevent the transmission of T. gondii among cats and wild animals in order to maintain the ecosystem health.


Assuntos
Herpestidae/parasitologia , Toxoplasma/imunologia , Toxoplasmose Animal/epidemiologia , Animais , Anticorpos Antiprotozoários/sangue , Centrifugação com Gradiente de Concentração/veterinária , Feminino , Japão/epidemiologia , Testes de Fixação do Látex/veterinária , Masculino , Prevalência , Estudos Soroepidemiológicos , Toxoplasma/isolamento & purificação
8.
J Vector Borne Dis ; 56(2): 105-110, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31397385

RESUMO

BACKGROUND & OBJECTIVES: Japanese encephalitis (JE) is a mosquitoe-borne viral zoonotic disease and globally around three billion people are at the risk of disease. The occurrence of JE cases has shown a rising trend during last decade in India. Pig is the amplifying host for JE virus and serves as a suitable sentinel model for the prediction of disease outbreak in humans. The development of a diagnostic test that is suitable for surveillance of JE in pigs is the need of the hour. The existing tests require elaborate laboratory facilities which make their application in rural settings difficult. Therefore, realizing the need for a rapid test, efforts were made to standardize a latex agglutination test (LAT) for serodiagnosis of JE in pigs. METHODS: Standardization of LAT by physical adsorption of recombinant NS1 (non-structural) protein of JE virus onto latex beads was done by altering six different variables, namely the antigen concentration, sensitization condition, surface blocking agent, blocking condition, particle concentration and reaction time. The standardized latex-protein complex was used for screening 246 pig serum samples under optimal conditions. RESULTS: The test was standardized with a diagnostic sensitivity and specificity of 82.24 and 87.83%, respectively. Screening of 246 field pig serum samples using standardized LAT showed a seropositivity of 50.4%. The results were available within 5 min after addition of test serum sample to the sensitized beads. INTERPRETATION & CONCLUSION: The findings of the study highlight the potential of LAT as a rapid on-site assay for JE diagnosis in pigs which would aid in predicting JE outbreaks in humans.


Assuntos
Anticorpos Antivirais/sangue , Encefalite Japonesa/imunologia , Testes de Fixação do Látex/normas , Proteínas não Estruturais Virais/genética , Zoonoses/diagnóstico , Animais , Vírus da Encefalite Japonesa (Espécie)/imunologia , Índia , Testes de Fixação do Látex/veterinária , Proteínas Recombinantes/imunologia , Sensibilidade e Especificidade , Suínos , Proteínas não Estruturais Virais/imunologia , Zoonoses/imunologia , Zoonoses/virologia
9.
J Microbiol Methods ; 162: 83-85, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31145941

RESUMO

A novel Com1 synthetic peptide-based latex agglutination test (LAT) was developed and evaluated against commercial ELISA kit for sero-screening of coxiellosis in cattle. The developed test is economical, has field applicability and can serve as an important rapid tool for sero-screening of coxiellosis in cattle.


Assuntos
Doenças dos Bovinos/diagnóstico , Coxiella burnetii/isolamento & purificação , Testes de Fixação do Látex/veterinária , Programas de Rastreamento/veterinária , Febre Q/diagnóstico , Febre Q/veterinária , Animais , Bovinos , Ensaio de Imunoadsorção Enzimática/veterinária , Sensibilidade e Especificidade
10.
J Vet Med Sci ; 79(12): 1968-1972, 2017 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-29070770

RESUMO

An indirect enzyme-linked immunosorbent assay (ELISA) using lipopolysaccharide extract as antigen was evaluated for detection of antibodies to Actinobacillus pleuropneumoniae serovar 15. The serovar 15 ELISA had a higher sensitivity and specificity than latex agglutination test for 63 and 80 sera from pigs experimentally infected and not infected with A. pleuropneumoniae, respectively. When the serovar 15 ELISA was applied to 454 field sera, high rates of seropositivity were found in pigs from farms infected with A. pleuropneumoniae serovar 15, but not in those from farms free of A. pleuropneumoniae serovar 15. The results suggest that the serovar 15 ELISA may be useful for the serological surveillance of infection with A. pleuropneumoniae serovar 15.


Assuntos
Infecções por Actinobacillus/veterinária , Actinobacillus pleuropneumoniae/imunologia , Anticorpos Antibacterianos/sangue , Ensaio de Imunoadsorção Enzimática/veterinária , Doenças dos Suínos/diagnóstico , Infecções por Actinobacillus/sangue , Infecções por Actinobacillus/diagnóstico , Infecções por Actinobacillus/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Testes de Fixação do Látex/veterinária , Sensibilidade e Especificidade , Suínos/microbiologia , Doenças dos Suínos/sangue , Doenças dos Suínos/imunologia
11.
Exp Parasitol ; 182: 9-15, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28867354

RESUMO

Visceral leishmaniasis is a public health problem worldwide. The early diagnosis in dogs is crucial, since they are an epidemiologically relevant reservoir of the disease. The aim of a field study is to early identify the disease allowing rapid intervention to reduce its effects. We propose an immunoagglutination test as a visual in situ method for diagnosis of canine visceral leishmaniasis. Latex-protein complexes were sensitized by covalent coupling of a chimeric recombinant antigen of Leishmania spp. onto polystyrene latex with carboxyl functionality. The reaction time and the antigen concentration under which the immunoagglutination assay shows greater discrimination between the responses of a positive control serum and a negative control serum were determined. Then, the latex-protein complexes were evaluated as a visual diagnostic tool with a panel of 170 sera. The test may be read between 2 and 5 min and can be performed even using sera with elevated concentration of lipids, bilirubin or with variable percentage of hemolysis. The sensitivity, the specificity and the diagnostic accuracy were 78%; 100% and >80%, respectively. The visual immunoagglutination test is of potential application as a method for field studies because it shows results in less than 5 min, it is easy to implement and does not require sophisticated equipment.


Assuntos
Anticorpos Antiprotozoários/sangue , Doenças do Cão/diagnóstico , Testes de Fixação do Látex/veterinária , Leishmania infantum/imunologia , Leishmaniose Visceral/veterinária , Animais , Antígenos de Protozoários/imunologia , Western Blotting/veterinária , Reservatórios de Doenças , Doenças do Cão/parasitologia , Cães , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/parasitologia , Proteínas Recombinantes/imunologia , Sensibilidade e Especificidade
12.
Vet Parasitol ; 244: 154-159, 2017 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-28917307

RESUMO

Abortion due to Toxoplasma gondii has been suspected in New Zealand farmed red deer. However, knowledge around the epidemiology and prevalence of T. gondii in farmed red deer is limited. The aim of this study was to firstly, assess the sensitivity and specificity of two commercially available assays, ELISA and latex agglutination test (LAT), for use in deer and secondly, to estimate the sero-prevalence of T. gondii in red deer. A total of 252 sera from rising 2-year-old and adult hinds from 17 New Zealand red deer herds at early and late pregnancy scanning and from known aborted and/or non-aborted hinds were tested for the presence of T. gondii antibodies. Each assays' sensitivity and specificity was evaluated by both the Western Blot (WB) as a gold standard method and Bayesian latent class (BLC) analysis in the absence of a gold standard. The sensitivity and specificity for WB were 95.8% (95% credible interval: 89.5-99.2%) and 95.1% (95% credible interval: 90.6-98.1%), respectively. For the LAT at the manufacturer's recommended ≥1:32 cut-off titre, the sensitivity (88.7%, 95% credible interval: 80.8-94.7%) and specificity (74.3%, 95% credible interval: 67.5-80.5%) were lower and higher than the sensitivity (76.2%, 95% credible interval: 66.7-84.5%) and specificity (89.7%, 95% credible interval: 84.5-93.9%) at a ≥1:64 cut-off, using (BLC) analysis. Sensitivity and specificity of the LAT at cut-off titre of 1:32 were estimated to be 84.4% (95% CI: 74.9-90.9%) and 73.5% (95% CI: 65.8-79.9%) against WB. The LAT had better agreement with WB at cut-off titre of ≥1:64 than ≥1:32 (Kappa=0.63 vs 0.54). At optimised cut-off S/P of 15.5%, the sensitivity (98.8%, 95% credible interval 96.1-99.8%) and specificity (92.8%, 95% credible interval 88.9-95.7%) of the ELISA were higher and lower, respectively, than the sensitivity (85.1%, 95% credible interval 76.2-91.9%) and specificity (98.5%, 95% credible interval 96.9-99.4%) at manufacturer's cut-off S/P of 30%, from BLC analysis. The sensitivity and specificity of ELISA at S/P cut-off of 15.5% was 91.1% (95% CI: 83.2-96.1%) and 90.7% (95% CI: 85.2-94.7%), respectively, when assessed against WB. The sero-prevalence from ELISA and LAT, at cut-off of S/P 15.5% and ≥1:64, respectively, was not significantly different to that from WB (McNemar's Chi-square p=0.21 for ELISA and p=0.28 for LAT).


Assuntos
Anticorpos Antiprotozoários/sangue , Cervos/parasitologia , Complicações Parasitárias na Gravidez/diagnóstico , Toxoplasma/imunologia , Toxoplasmose Animal/diagnóstico , Aborto Animal , Testes de Aglutinação/veterinária , Animais , Teorema de Bayes , Western Blotting/veterinária , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Testes de Fixação do Látex/veterinária , Gravidez , Complicações Parasitárias na Gravidez/parasitologia , Sensibilidade e Especificidade , Toxoplasma/isolamento & purificação , Toxoplasmose Animal/epidemiologia , Toxoplasmose Animal/parasitologia
13.
Arq. bras. med. vet. zootec ; 68(4): 1090-1094, jul.-ago. 2016. ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-868453

RESUMO

O objetivo deste estudo foi detectar rotavírus em fezes de bezerros com diarreia em Uberaba, MG, e caracterizar os genes VP7 e VP4 por meio da genotipagem e da análise filogenética. Setenta e quatro amostras foram coletadas entre novembro de 2008 e setembro de 2009. A detecção do vírus foi feita por teste de aglutinação e as amostras positivas foram submetidas à transcrição reversa, seguida de reação em cadeia da polimerase (RT-PCR), tipagem por PCR e sequenciamento. A taxa de detecção de rotavírus foi de 6,8% e todas as amostras apresentaram o genótipo G6P[5]. A análise filogenética mostrou que as amostras do genótipo G6 pertencem à linhagem IV e que, para ambos os genes (VP7 e VP4), as amostras deste estudo compõem um sub-cluster à parte daquele das cepas referências e das amostras campo mais similares. O alinhamento das sequências de aminoácidos deduzidas mostrou substituições em regiões antigênicas quando comparadas com as sequências das cepas bovinas UK e NCDV, presentes nas vacinas disponíveis no Brasil. Uma nova sublinhagem genética de G6P[5] foi evidenciada neste estudo. Substituições de aminoácidos nas regiões antigênicas dos rotavírus e a circulação de novas variantes podem representar desafios para as vacinas utilizadas atualmente. O presente estudo contribui para a compreensão da epidemiologia dos rotavírus bovinos no Brasil.(AU)


Assuntos
Animais , Bovinos , Técnicas de Genotipagem/veterinária , Rotavirus , Vacinas contra Rotavirus/genética , Testes de Fixação do Látex/veterinária
14.
Trop Anim Health Prod ; 47(7): 1329-35, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26065562

RESUMO

This study aimed to develop latex agglutination test (LAT) using recombinant leptospiral immunoglobulin-like protein (LigB) (rLigB) antigen and compare its diagnostic efficacy with LAT using conventional heat-killed leptospiral antigen and microscopic agglutination test (MAT) in diagnosing bovine leptospirosis. The PCR-amplified 1053-bp ligB gene sequences from Leptospira borgpetersenii Hardjo serovar were cloned in pET 32 (a) vector at EcoRI and NotI sites and expressed in BL21 E. coli cells as fusion protein with thioredoxin (-57 kDa) and characterized by SDS-PAGE and immunoblot. Out of 390 serum samples [cattle (n = 214), buffaloes (n = 176)] subjected to MAT, 115 samples showed reciprocal titre≥100 up to 1600 against one or more serovars. For recombinant LigB protein/antigen-based LAT, agglutination was observed in the positive sample, while no agglutination was observed in the negative sample. Similarly, heat-killed leptospiral antigen was prepared from and used in LAT for comparison with MAT. A two-sided contingency table was used for analysis of LAT using both the antigens separately against MAT for 390 serum samples. The sensitivity, specificity and positive and negative predictive values of recombinant LigB LAT were found to be 75.65, 91.27, 78.38 and 89.96 %, respectively, and that of heat-killed antigen-based LAT were 72.17, 89.82, 74.77 and 88.53 %, respectively, in comparison with MAT. This developed test will be an alternative/complementary to the existing battery of diagnostic assays/tests for specific detection of pathogenic Leptospira infection in bovine population.


Assuntos
Antígenos de Bactérias/imunologia , Doenças dos Bovinos/diagnóstico , Testes de Fixação do Látex/veterinária , Leptospira/imunologia , Leptospirose/veterinária , Animais , Anticorpos Antibacterianos/imunologia , Bovinos , Doenças dos Bovinos/sangue , Doenças dos Bovinos/imunologia , Eletroforese em Gel de Poliacrilamida/veterinária , Ensaio de Imunoadsorção Enzimática/veterinária , Leptospirose/diagnóstico , Leptospirose/imunologia , Proteínas Recombinantes/imunologia , Sensibilidade e Especificidade , Testes Sorológicos/veterinária
15.
Vet Parasitol ; 205(3-4): 460-5, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-25224790

RESUMO

Serodiagnosis of surra is commonly performed with the CATT/Trypanosoma evansi direct agglutination test. This antibody detection test is based on lyophilised bloodstream form trypanosomes propagated in rats and presenting the predominant variant surface glycoprotein (VSG) RoTat 1.2 on their surface. Recently, the N-terminal fragment of VSG RoTat 1.2 has been expressed as a recombinant protein in the yeast Pichia pastoris and showed diagnostic potential in ELISA. This recombinant antigen has now been incorporated in a latex agglutination test, the rLATEX/T. evansi. In this study, we compared the diagnostic accuracy of rLATEX/T. evansi and CATT/T. evansi with immune trypanolysis (TL) as reference test on a total of 1717 sera from camels, horses, bovines, water buffaloes, dogs and sheep. The rLATEX/T. evansi displayed a slightly better agreement with TL than CATT/T. evansi (kappa [κ] respectively 0.84 and 0.72). The sensitivities of rLATEX/T. evansi (84.2%, 95% CI 80.8-87.1) and CATT/T. evansi (84.0%, 95% CI 80.6-87.0) were similar, but rLATEX/T. evansi was significantly more specific (97.7%, 95% CI 96.7-98.4) than CATT/T. evansi (89.4%; 95% CI 87.6-91.1). We consider the rLATEX/T. evansi an alternative for the CATT/T. evansi, with the advantage that the use of a purified recombinant antigen leads to a more standardised diagnostic test with an improved specificity. Moreover, it eliminates the use of laboratory animals and can be easily scaled-up, e.g. in biofermentors.


Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Camelus/parasitologia , Glicoproteínas de Membrana/imunologia , Trypanosoma/imunologia , Tripanossomíase/veterinária , Testes de Aglutinação/veterinária , Animais , Búfalos , Bovinos , Cães , Cavalos , Testes de Fixação do Látex/veterinária , Proteínas de Protozoários/imunologia , Ratos , Proteínas Recombinantes , Sensibilidade e Especificidade , Ovinos
16.
Parasitol Int ; 63(4): 638-9, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24780140

RESUMO

The presence of antibodies to Toxoplasma gondii in livestock and poultry was investigated by latex agglutination tests; samples that agglutinated at dilutions of 1:64 or higher were regarded as positive. Sera were collected from fattening beef cattle (102 Japanese black, 105 crossbreeds and 114 castrated Holstein), culled dairy cattle (101 Holstein), 100 horses, 115 fattening pigs and 235 chickens (163 free-range and 72 broilers) at abattoirs in Gifu Prefecture, Japan, from August 2012 to August 2013. Antibodies to T. gondii were found in 7.3% (31/422) in cattle, 5.2% (8/155) in pigs, but not in horses or chickens. These results suggest that toxoplasmosis may be transmitted to humans via consumption of T. gondii-infected raw beef in Japan.


Assuntos
Doenças dos Bovinos/epidemiologia , Doenças dos Cavalos/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Doenças dos Suínos/epidemiologia , Toxoplasma/isolamento & purificação , Toxoplasmose Animal/epidemiologia , Animais , Anticorpos Antiprotozoários/isolamento & purificação , Bovinos , Doenças dos Bovinos/sangue , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/prevenção & controle , Galinhas , Doenças dos Cavalos/sangue , Doenças dos Cavalos/parasitologia , Doenças dos Cavalos/prevenção & controle , Cavalos , Japão/epidemiologia , Testes de Fixação do Látex/veterinária , Doenças das Aves Domésticas/sangue , Doenças das Aves Domésticas/parasitologia , Doenças das Aves Domésticas/prevenção & controle , Prevalência , Estudos Soroepidemiológicos , Suínos , Doenças dos Suínos/sangue , Doenças dos Suínos/parasitologia , Doenças dos Suínos/prevenção & controle , Toxoplasma/imunologia , Toxoplasmose Animal/sangue , Toxoplasmose Animal/parasitologia , Toxoplasmose Animal/prevenção & controle
17.
J Vet Med Sci ; 76(9): 1257-9, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24849051

RESUMO

Toxoplasma gondii is a zoonotic protozoan parasite that infects humans and domestic animals. In this study, the seroprevalence of T. gondii antibodies was investigated using serum samples collected from 83 sheep, 146 goats and 37 cattle from a dozen subsistence farms in Bangladesh. Fifty-eight out of 83 sheep (69.9%), 89 out of 146 goats (61.0%) and 10 out of 37 cattle (27.0%) were seropositive for the parasite. Seroprevalence in young goats (<1 year old) was significantly lower than that of the adult goats (>1 year old). In contrast, seroprevalence for young and adult sheep was similar. These results indicate that acquired infection with T. gondii occurs in this region of Bangladesh, at least among goats.


Assuntos
Doenças dos Bovinos/parasitologia , Doenças das Cabras/parasitologia , Doenças dos Ovinos/parasitologia , Toxoplasma/isolamento & purificação , Toxoplasmose Animal/parasitologia , Zoonoses/parasitologia , Fatores Etários , Animais , Anticorpos Antiprotozoários/sangue , Bangladesh/epidemiologia , Bovinos , Doenças dos Bovinos/sangue , Doenças dos Bovinos/epidemiologia , Doenças das Cabras/sangue , Doenças das Cabras/epidemiologia , Cabras , Humanos , Testes de Fixação do Látex/veterinária , População Rural , Estudos Soroepidemiológicos , Ovinos , Doenças dos Ovinos/sangue , Doenças dos Ovinos/epidemiologia , Toxoplasmose Animal/sangue , Toxoplasmose Animal/epidemiologia , Zoonoses/sangue , Zoonoses/epidemiologia
18.
J Vet Diagn Invest ; 26(1): 136-40, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24398907

RESUMO

Neospora caninum is an apicomplexan parasite responsible for paresis in dogs and abortion in cattle worldwide. Dogs serve as a definitive host, while cattle serve as intermediate host. Many different methods have been developed to detect specific antibodies present in cattle and dog serum. In the present study, the dense granule protein NcGRA6 was incorporated in a latex beads agglutination test (LAT), and compared to other serological methods, including enzyme-linked immunosorbent assay, the direct agglutination test, the immunoblot, and the indirect fluorescent antibody test (IFAT). Using the IFAT as the reference method, 100 sera isolated from Algerian cattle and 100 sera isolated from Algerian dogs, both possibly infected with N. caninum, were used to evaluate the LAT. The sensitivity, specificity, and kappa index were calculated for each host species and assay. For dog sera, the sensitivity and the specificity of the LAT was 76% and 100%, respectively. The McNemar test showed that the LAT was not significantly different from IFAT (P > 0.05). For cattle sera, the sensitivity and the specificity of the LAT were 60% and 100%, respectively. The McNemar test indicated that the LAT was significantly different from IFAT (P < 0.01) and that the LAT was only positive for cattle sera with titers of 1:800 or greater, indicating that LAT can be used for cattle in a clinical context. As well, the LAT has the advantage of being easy and rapid to perform compared to the other assays.


Assuntos
Anticorpos Antiprotozoários/sangue , Doenças dos Bovinos/parasitologia , Coccidiose/veterinária , Doenças do Cão/parasitologia , Testes de Fixação do Látex/veterinária , Neospora/isolamento & purificação , Argélia , Animais , Bovinos , Doenças dos Bovinos/sangue , Coccidiose/sangue , Doenças do Cão/sangue , Cães , Testes de Fixação do Látex/métodos , Testes de Fixação do Látex/normas , Proteínas de Protozoários , Sensibilidade e Especificidade
19.
J Dairy Sci ; 97(2): 829-37, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24359821

RESUMO

The objectives of this study were to determine the occurrence and diversity of Staphylococcus spp. in milk from healthy cows and cows with subclinical mastitis in Brazil and to examine the profile of enterotoxin genes and some enterotoxins produced by Staphylococcus spp. A total of 280 individual mammary quarter milk samples from 70 healthy cows and 292 samples from 73 cows with subclinical mastitis were collected from 11 farms in the state of São Paulo, Brazil. Staphylococcus spp. were recovered from 63 (22.5%) samples from healthy cows and from 80 samples (27.4%) from cows with mastitis. The presence of Staphylococcus aureus was significantly different between these 2 groups and was more prevalent in the cows with mastitis. The presence of Staphylococcus saprophyticus was also significantly different between these 2 groups, but this organism was more prevalent in healthy cows. No statistically significant differences were observed in the numbers of other staphylococci in milk samples from the 2 groups. The sea gene was the most prevalent enterotoxin gene in both groups. Eight of 15 (53.3%) Staph. aureus carried this gene and all produced the SEA toxin. In the coagulase-negative staphylococci (CNS) group, 61 of 128 (47.5%) had the same gene and just 1 (1.6%) Staphylococcus epidermidis strain produced the enterotoxin in vitro. Because CNS were isolated from both groups of cows and most CNS contained enterotoxin genes but did not produce toxins, the role of CNS in mastitis should be carefully defined.


Assuntos
Doenças dos Bovinos/epidemiologia , Enterotoxinas/genética , Genes Bacterianos , Mastite Bovina/epidemiologia , Staphylococcus/fisiologia , Animais , Infecções Assintomáticas/epidemiologia , Brasil/epidemiologia , Bovinos , Doenças dos Bovinos/microbiologia , Enterotoxinas/metabolismo , Feminino , Testes de Fixação do Látex/veterinária , Mastite Bovina/microbiologia , Microbiota , Leite/microbiologia , Reação em Cadeia da Polimerase/veterinária , Staphylococcus/genética
20.
J Vet Med Sci ; 76(2): 265-7, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24107428

RESUMO

Toxoplasmosis, an important zoonosis, can be transmitted by eating meat or drinking milk of animals infected with Toxoplasma gondii. Samples were collected from 238 donkeys in the year 2010 in Italy, which included 207 females and 31 males of five breeds and crossbreeds with the average age 9 years (1 month-24 years). Sera were tested for T. gondii antibodies using a latex agglutination test and the indirect fluorescent antibody test; 5 and 8% seropositivity were recorded, respectively. We found significant correlation between the presence of T. gondii antibodies and sex, age, grazing and presence of cats on the farms and their access to donkey feed. This is the first detection of T. gondii antibodies in donkeys in Italy.


Assuntos
Equidae , Toxoplasma , Toxoplasmose Animal/epidemiologia , Fatores Etários , Animais , Gatos , Feminino , Técnica Indireta de Fluorescência para Anticorpo/veterinária , Itália/epidemiologia , Testes de Fixação do Látex/veterinária , Masculino , Estudos Soroepidemiológicos , Fatores Sexuais
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