Study on prevalence and liver function test enzymes of differently plumaged peafowls (Pavo cristatus) infected with Toxoplasma gondii in captivity / [Estudo sobre enzimas de prevalência e teste da função hepatica de pavões de plumage diferente (Pavo cristatus) infectados com Toxoplasma gondii em cativeiro]

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)

Production of a latex agglutination reagent for the rapid diagnosis of cryptococcal meningitis / Producción de un reactivo de látex para el diagnóstico rápido de criptococosismeníngea

Abstract Cryptococcosis is a fungal disease affecting more than one million people per yearworldwide. Its main etiological agents are Cryptococcus neoformans species complex and Cryp-tococcus gattii species complex. Cryptococcal meningitis (CM) is considered an AIDS-definingcondition. Rapid diagnosis by cryptococcal antigen assays, either the latex agglutination test(LA) or the lateral flow assay, is key to decreasing mortality due to cryptococcal disease. Theaim of the study was to develop a latex agglutination reagent (LA-ANLIS) for the rapid and reliable diagnosis of cryptococcosis in Argentina. This reagent will be produced in order to supplythe NMLN (National Mycology Laboratory Network). The evaluation of LA-ANLIS performanceand its comparison with the Cryptococcus Antigen Latex Agglutination Test System (LA-IMMY)(Immuno-Mycologics, Inc., USA) were conducted in 94 samples of cerebrospinal fluid. LA-ANLISand LA-IMMY compared exhibited 100% positive agreement and 97% negative agreement. LA-ANLIS showed 94% sensitivity and 97% specificity with the positive and negative predictivevalues of 94% and 97%, respectively. The LA-ANLIS is a reliable, reproducible and cost-effectivereagent, especially useful in countries where the commercial kit is not generally available andmust be obtained at a high cost. National production of reagents is the best choice for a reliableaccess to the rapid diagnosis of CM in Argentina.

Resumen La criptococosis es una enfermedad fúngica que afecta a más de un millón de personas por año en todo el mundo. Los principales agentes etiológicos pertenecen a los complejos de especies Cryptococcus neoformans y Cryptococcus gattii. La criptococosis meníngea (CM) se considera una enfermedad marcadora de sida. El diagnóstico rápido de esta enfermedad a través de la detección del antígeno de Cryptococcus, ya sea por aglutinación en partículas de látex o por inmunocromatografía, es clave para disminuir la mortalidad. El objetivo del presente estudio fue desarrollar un reactivo de aglutinación en partículas de látex para el diagnóstico rápido y certero de la CM en Argentina. Este reactivo (denominado en adelante LA-ANLIS) será producido para abastecer a la Red Nacional de Laboratorios de Micología. Se evaluó el desempeno del reactivo LA-ANLIS, y se realizó una comparación con el reactivo comercial Immuno-Mycologics, Inc. (en adelante, LA-IMMY) utilizando 94 muestras de líquido cefalorraquídeo. Hubo un 100% de acuerdo positivo y un 97% de acuerdo negativo entre los resultados obtenidos con los reactivos LA-ANLIS y LA-IMMY. El reactivo LA-ANLIS mostró una sensibilidad del 94% y una especificidad del 97%; los valores predictivos positivo y negativo fueron del 94 y del 97%, respectivamente. Se concluye que el LA-ANLIS es un reactivo confiable y rentable, que arroja resultados reproducibles, por lo que es especialmente útil en países donde los reactivos comerciales generalmente no están disponibles o sus costos son elevados. La producción nacional de reactivos es la mejor opción para asegurar el acceso de todos los hospitales al diagnóstico rápido de la CM en Argentina.

Método de aglutinación en látex para el diagnóstico rápido del síndrome de Guillain-Barré / Latex agglutination method for fast Guillain-Barré syndromes diagnosis

El síndrome de Guillain-Barré es una polirradiculoneuropatía aguda, en la cual está involucrado un componente autoinmunitario, posterior a un proceso infeccioso en pacientes no vacunados o vacunados. A partir de la aparición del virus del dengue y del Zika en el continente americano es de esperar que exista una mayor probabilidad de encontrar pacientes con este síndrome post-infeccioso. Por tanto, poder contar con un método diagnóstico rápido pudiera ser de utilidad en los centros de asistencia que reciben casos de urgencias. Se procede a modificar un método para cuantificar albuminuria por aglutinación con partículas de látex sensibilizados, para la detección de este analito en el líquido cefalorraquídeo de aquellos pacientes con sospecha de esta enfermedad. Se comprueba que el método puede ser utilizado como método de diagnóstico rápido del síndrome de Guillain-Barré(AU)

Guillain-Barré Syndrome is an acute poliradiculoneuropathy with an autoimmune component, subsequent to an infectious process in vaccinated or non-vaccinated patients. From the spreading of dengue and Zika infections in the American continent it is expected a greater probability of finding patients with this post-infectious syndrome. Therefore, a rapid diagnostic test could be useful in emergency assistance centers. A quantitative latex agglutination test to detect albuminuria was modified to be used in cerebrospinal fluid of patients with presumptive diagnosis of this disease. It has been proved that the developed test can be used for diagnostic rapid of Guillain-Barré syndrome(AU)

Differentiation of Candida albicans and Candida dubliniensis using Latex Agglutination Test / 대한의진균학회지

BACKGROUND: Candida dubliniensis is phenotypically similar to Candida albicans that may be underdiagnosed in clinical laboratory. In 2010, C. dubliniensis was first recovered from blood of a candidemia patient in Seoul, Korea. Also, a simple commercial latex agglutination (LA) test is available. OBJECTIVE: The aim of the present study was to investigate the prevalence of C. dubliniensis among isolates in our stocks during 2-years period (2010-2011) and to evaluate the ability of LA test (Bichro-Dubli Fumouze®) for the differentiation of C. albicans and C. dubliniensis. METHODS: A total 509 isolates including 504 C. albicans and 5 C. dubliniensis were examined for LA test, the presence of “spiking” on blood agar plate, and the germ tube test. Also all isolates were tested using the VITEK 2 ID-YST system. RESULTS: No C. dubliniensis was found in 504 isolates of initially identified as C. albicans. The LA test was positive only in 5 clinical isolates and 2 type strains of C. dubliniensis. CONCLUSIONS: The data show that the prevalence of C. dubliniensis in Korea is still expected to be extremely low and LA test is very rapid, simple, and reliable tool for the differentiation of C. albicans and C. dubliniensis.

Analysis of bovine rotavirus strains circulating in diarrheic dairy calves in Uberaba, Minas Gerais, Brazil, during 2008-2009 / Análise de cepas de rotavírus bovino circulantes em bezerros leiteiros com diarreia em Uberaba, Minas Gerais, Brasil, durante 2008-2009

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)

Comparison of Automated Treponemal and Nontreponemal Test Algorithms as First-Line Syphilis Screening Assays

BACKGROUND: Automated Mediace Treponema pallidum latex agglutination (TPLA) and Mediace rapid plasma reagin (RPR) assays are used by many laboratories for syphilis diagnosis. This study compared the results of the traditional syphilis screening algorithm and a reverse algorithm using automated Mediace RPR or Mediace TPLA as first-line screening assays in subjects undergoing a health checkup. METHODS: Samples from 24,681 persons were included in this study. We routinely performed Mediace RPR and Mediace TPLA simultaneously. Results were analyzed according to both the traditional algorithm and reverse algorithm. Samples with discordant results on the reverse algorithm (e.g., positive Mediace TPLA, negative Mediace RPR) were tested with Treponema pallidum particle agglutination (TPPA). RESULTS: Among the 24,681 samples, 30 (0.1%) were found positive by traditional screening, and 190 (0.8%) by reverse screening. The identified syphilis rate and overall false-positive rate according to the traditional algorithm were lower than those according to the reverse algorithm (0.07% and 0.05% vs. 0.64% and 0.13%, respectively). A total of 173 discordant samples were tested with TPPA by using the reverse algorithm, of which 140 (80.9%) were TPPA positive. CONCLUSIONS: Despite the increased false-positive results in populations with a low prevalence of syphilis, the reverse algorithm detected 140 samples with treponemal antibody that went undetected by the traditional algorithm. The reverse algorithm using Mediace TPLA as a screening test is more sensitive for the detection of syphilis.

Subconjunctival and topical application of recombinant tissue plasminogen activator in rabbits / Uso tópico e subconjuntival de ativador de plasminogênio tecidual recombinante em coelhos

Purpose: To quantify fibrin degradation products after topical and subconjunctival administration of recombinant tissue plasminogen activator in rabbits. Methods: Fibrin formation was induced in the anterior chamber in 25 rabbits. Subsequently, five rabbits received an injection of r-TPA (positive control) in the anterior chamber, another 10 received a subconjunctival injection of r-TPA, and the remaining 10 received instillations of topical r-TPA. Afterwards, samples of aqueous humor were collected and semi-quantitative analysis of fibrin degradation products (FDP) was performed. Results: No statistical differences were noted between the treatment and control groups at any time point. Fibrin degradation products semi-quantification showed statistical improvement in the control group and the subconjunctival group. Conclusion: Fibrin degradation products were observed in the anterior chamber after subconjunctival administration of r-TPA. However, it was probably not sufficient to cause fibrin degradation. Topical r-TPA did not effectively absorb anterior chamber fibrin. .

Objetivo: Quantificar produtos de degradação de fibrina (PDF) após uso tópico e subconjunctival de ativador de plasminogênio tecidual recombinante (r-TPA) em coelhos. Métodos: Formação de fibrina foi induzida na câmara anterior em 25 coelhos. Cinco coelhos foram submetidos a injeção intracameral de r-TPA (controle positivo). Dez coelhos foram submetidos a injeção subconjuntival de r-TPA e dez coelhos foram submetidos a instilação tópica de r-TPA. Amostras de humor aquoso foram coletados e uma análise quantitativa dos produtos de degradação de fibrina foi realizada. Resultados: Não foi observado diferença estatisticamente significativa na degradação de fibrina em nenhum dos momentos estudados quando comparados com o controle. Porém foi observado diferença estatisticamente significante na quantificação do produtos de degradação de fibrina no grupo controle e no grupo subconjuntival. Conclusão: Produtos de degradação de fibrina foi observado nas amostras do grupo subconjunctival, porém, provavelmente não foi suficiente para degradar a fibrin presente. r-TPA tópico não foi efetivo em absorver fibrina na câmara anterior. .

Evaluación de las pruebas dot blot y aglutinación de látex para el diagnóstico de cisticercosis en Perú / Assessment of dot blot tests and latex agglutination for cysticercosis diagnostic in Peru

Con el objetivo de evaluar las pruebas dot blot y aglutinación de látex para la detección de cisticercosis humana con antígeno de líquido de cisticerco de Taenia solium, se usaron 125 sueros humanos, de los cuales 60 procedían de personas con cisticercosis confirmada por Western Blot, 45 de personas con otras enfermedades parasitarias y 20 de personas aparentemente sanas. La concentración óptima del antígeno para impregnar las tiras dot blot fue de 0,01 ug/uL, y para impregnar las partículas de látex fue de 0,092 ug/uL. Para la prueba dot blot se encontró una sensibilidad del 100% y especificidad del 87,7%; para la aglutinación de látex una sensibilidad del 93,3% y especificidad del 89,2%. Ambas pruebas podrían ser de utilidad y factibles de implementar como alternativas de diagnóstico serológico en laboratorios de áreas endémicas del Perú.

In order to evaluate dot blot tests and latex agglutination for the detection of human cysticercosis with liquid antigen of Taenia solium cysticerci, 125 human sera were used, of which 60 were from people with cysticercosis confirmed by Western Blot, 45 with other parasitic diseases and 20 apparently healthy. The optimal concentration of antigen to impregnate dot blot strips was 0.01 ug/uL, and to impregnate the latex particles was 0.092 ug/uL. For the dot blot test, a sensitivity of 100% and specificity of 87.7% was found. For latex agglutination, a sensitivity of 93.3% and specificity of 89.2% was found. Both tests may be useful and feasible to implement alternatives of serological diagnosis in laboratories in endemic areas of Peru.

Detecção de rotavírus do grupo A em amostras fecais: adaptação do teste de aglutinação em látex para o emprego de anticorpos IgY anti-Rotavírus A / Detection of group a rotavirus in fecal samples: adaptation of latex agglutination test for anti-rotavirus a igy antibody employment

A infecção pelo rotavírus A (RVA) é responsável por cerca de 453.000 mortes anualmente e aproximadamente 40 por cento das hospitalizações por diarreia em crianças menores de cinco anos em todo o mundo, sendo o principal causador de gastroenterite aguda nesse grupo populacional. O desenvolvimento de um método de diagnóstico rápido, barato, sensível e específico para a detecção de RVA é importante do ponto de vista epidemiológico porque permite identificar surtos no local de ocorrência. O uso da imunoglobulina Y (IgY), anticorpo purificado a partir da gema de ovo, vem crescendo nos últimos anos, devido às características vantajosas quando comparada com a imunoglobulina G (IgG), como a obtenção de anticorpos de forma não invasiva e a produção de anticorpos em grandes concentrações. Este trabalho objetivou a adaptação de um teste de diagnóstico através da substituição do anticorpo de captura IgG pela IgY específica para o antígeno de RVA (LATEXY-ROTA). Para isto 09 frangas poedeiras foram imunizadas com o RVA, os ovos foram coletados e a IgY purificada a partir da gema do ovo por polietileno glicol 6.000, seguida da purificação adicional por cromatografia de troca iônicaA IgY anti-RVA purificada foi ligada covalentemente à partículas de poliestireno e usada como insumo na adaptação de um teste de aglutinação em látex, sendo testada em um painel de amostras fecais sabidamente positivas e negativas previamente selecionadas pelo Centro Regional de Referência para Rotaviroses do Laboratório de Virologia Comparada e Ambiental (LVCA/IOC-FIOCRUZ)...

Foi obtida uma sensibilidade de 75 por cento e uma especificidade de 87,5 por cento quando o LATEXY-ROTA foi comparado com um teste imunoenzimático comercial disponível (padrão ouro). Quando comparado com dois testes comerciais de aglutinação em látex testados no painel de amostras utilizando a IgG, o LATEXY-ROTA obteve uma sensibilidade de 100 por cento e especificidade de 88,24 por cento. Baseado nos dados obtidos, sugerimos a viabilidade da substituição da IgG por IgY no ensaio de aglutinação pelo látex...

The infection by rotavirus (RV) is responsible for approximately 453,000 deaths annually and approximately 40 percent of hospitalizations by diarrhea in children under five years worldwide, being the major cause of acute gastroenteritis in this populationgroup. The development of a rapid method, inexpensive, sensitive and specific for rotavirus diagnosis is important from the disease because it allows the identification of outbreaks in the site of occurrence. The use of Immunoglobulin Y (IgY) antibodypurified from egg yolk, has been grown in recent years, due to the advantageous features compared to immunoglobulin G (IgG), as a noninvasive recovery of antibodies and production in high concentrations. The aim of this method was to adapt a diagnostic test by replacing the IgG capture antibody by specific IgY for RVAantigen (LATEXY-ROTA). For that, 09 laying hens were immunized with RVA, the eggs were collected and IgY purified from egg yolk by polyethylene glycol 6,000, followed by purification by ion exchange chromatography. The purified anti-IgY RVA was covalently bound to polystyrene particles, being tested in a panel of positive and negative fecal samples previously determined by the Rotavirus Regional ReferenceCenter of Comparative and Environmental Virology Laboratory (LVCA/IOCFIOCRUZ). A sensitivity of 75% and specificity of 85,7% was observed when the adapted test was compared to a commercial available enzyme immunoassay (goldenstandard). When compared to two commercial latex agglutination tests using the IgG tested on the panel of samples, the LATEXY-ROTA had a sensitivity of 100 percent and specificity of 88.2 percent. Based on the obtained data, we suggest the feasibility of replacing the IgG by IgY in the latex agglutination assay...

Evaluation of different methods to detect methicillin resistance in Staphylococcus aureus [MRSA]

The studies suggest that dogs living with human are potential risk of becoming MRSA carrier and increased risk of infections caused by MRSA. Phenotypic methods to detect methicillin resistance in Staphylococcus aureus [MRSA] are inadequate. The objective of the present study was to determine methicillin resistance in S. aureus by phenotypic susceptibility test [oxacillin disk diffusion, cefoxitin disk diffusion, oxacillin screen agar] and molecular methods [PCR as a gold standard] and the latex agglutination test for the detection of PBP2a and to evaluate the results of these tests for its sensitivity and specificity. A total of 100 swab samples were taken from muzzle site, in more contact with human, of dogs and MRSA were isolated. Oxacillin [1 micro g], cefoxitin [30 micro g] disk diffusion and oxacillin screen agar method were used. The isolates were also subjected to latex agglutination test for detection of PBP2a and PCR to detect mecA gene. By PCR 37% of isolates show the presence of mecA. Latex agglutination was found to be the most sensitive [97.29%] and cefoxitin disk diffusion to be the most specific [96.82%] tests for detection of MRSA. Our finding showed that combining oxacillin screen agar or cefoxitin disk diffusion with latex agglutination improves sensitivity and specificity to detect methicillin resistance S. aureus [MRSA] isolates

Development and assessment of a latex agglutination test based on recombinant MSP5 to detect antibodies against Anaplasma marginale in cattle

The recombinant protein MSP5 has been established as an important antigen for serological diagnosis of Anaplasma marginale by enzyme-linked immunosorbent assay (ELISA). However, due to the high cost of specialized equipment, this technique is not accessible to all laboratories, especially in developing countries in areas where the disease is endemic. The present study describes the standardization of a latex agglutination test (LAT) to detect antibodies against A. marginale based on recombinant MSP5. Compared with indirect enzyme-linked immunosorbent assay (iELISA), the relative sensitivity and specificity of the LAT were 95.21% and 91.86% respectively, with an almost perfect agreement between tests (kappa index = 0.863). These results can be considered important for the serological diagnosis of A. marginale, as they indicate that the test represents a rapid and low cost alternative to ELISA.

Prevalence and characteristics of Shiga toxin-producing Escherichia coli (STEC) from cattle in Korea between 2010 and 2011

A total of 156 Shiga-like toxin producing Escherichia coli (STEC) were isolated from fecal samples of Korean native (100/568, 18%) and Holstein dairy cattle (56/524, 11%) in Korea between September 2010 and July 2011. Fifty-two STEC isolates (33%) harbored both of shiga toxin1 (stx1) and shiga toxin2 (stx2) genes encoding enterohemolysin (EhxA) and autoagglutinating adhesion (Saa) were detected by PCR in 83 (53%) and 65 (42%) isolates, respectively. By serotyping, six STEC from native cattle and four STEC from dairy cattle were identified as O-serotypes (O26, O111, O104, and O157) that can cause human disease. Multilocus sequence typing and pulsed-field gel electrophoresis patterns highlighted the genetic diversity of the STEC strains and difference between strains collected during different years. Antimicrobial susceptibility tests showed that the multidrug resistance rate increased from 12% in 2010 to 42% in 2011. Differences between isolates collected in 2010 and 2011 may have resulted from seasonal variations or large-scale slaughtering in Korea performed to control a foot and mouth disease outbreak that occurred in early 2011. However, continuous epidemiologic studies will be needed to understand mechanisms. More public health efforts are required to minimize STEC infection transmitted via dairy products and the prevalence of these bacteria in dairy cattle.

Identificación de Neisseria gonorrhoeae. Utilidad de la tarjeta 2 NH del sistema Vitek 2C / [Neisseria gonorrhoeae identification. Usefulness of the Vitek 2C NH card].

A total of 115 unique clinical isolates of Neisseria gonorrhoeae and 54 strains of other genera and species included in the database of the NH card were tested by the Vitek 2C System (bioMÞrieux, Marcy L’Etoile, Francia). The gonoccocal isolates had been previously identified by conventional biochemical tests and by the latex agglutination test with monoclonal antibodies using the Phadebact Monoclonal GC Test (Bactus AB, Sweden). The NH card correctly identified 111 (96.5

) strains of 115 isolates; one strain was identified with low discriminatory power (0.86

) was misidentified (as Neisseria meningitidis) whereas the other two (1.7

) remained unidentified. The NH card for N. gonorrhoeae identification provided 100

specificity. The results were available within 6 hours. The NH card could be considered a reliable and useful tool for routine use in Neisseria gonorrhoeae identification.

Development of a peptide based latex agglutination assay for serotype identification of foot and mouth disease virus.

Out of 200 serum samples collected from cattle (142) and buffaloes (58) of various ages and sexand subjected to latex agglutination test (LAT) using serotype specific peptides (O, A, Asia 1) and also with peptide for non-structural protein 2B (NSP-2B), 114 (70%) samples were positive against FMDV type ‘O’, 102 (51%) against serotype ‘A’ and 104 (52%) against serotype ‘Asia 1’. With NSP-2B peptide a total of 71 (35.5%) samples were positive. The results suggest that LAT could be used for the diagnosis of foot and mouth disease virus as it is easy, cheap and effective test.

Comparative study between immunoturbidimetric and latex agglutination methods for the detection of rheumatoid factor / Estudo comparativo entre as técnicas de aglutinação em látex e de imunoturbidimetria para a detecção de fator reumatoide

INTRODUCTION: The rheumatoid factor (RF) is the most common antibody found in patients with rheumatoid arthritis. It is an inflammatory chronic disease characterized by articular involvement, inflammation of synovial fluid, tissue infiltration by leucocytes and joint destruction, which ultimately determine articular deformities. The rheumatoid factor is found in 70%-80% of the adult population and in 10% of the young population. OBJECTIVE: The aim of this research was to compare immunoturbidimetric and latex agglutination methods for the detection of RF in serum. RESULTS: The immunoturbidimetric method displayed sensitivity (95.2%), specificity (89.4%) and high positive correlation (R² = 0,8077) with the latex agglutination method in positive serum samples. CONCLUSION: The study allowed to demonstrate that both immunoturbidimetric and latex agglutination methods equally discriminate between negative and positive serum samples for RF.

INTRODUÇÃO: O fator reumatoide (FR) é o autoanticorpo mais comum encontrado em pacientes com artrite reumatoide, uma doença crônica inflamatória caracterizada pelo envolvimento articular com inflamação do líquido sinovial, infiltração de tecido por leucócitos e destruição das articulações, que acaba por determinar deformidades articulares. O FR é encontrado em 70%-80% da população adulta e em 10% da população juvenil. OBJETIVO: Comparar os métodos de imunoturbidimetria e aglutinação (prova do látex) para a determinação de FR em soro. RESULTADO: Foi possível observar que o método imunoturbidimétrico apresenta sensibilidade (95,2%), especificidade (89,4%) e correlação positiva elevada (R² = 0,8077) com o método de aglutinação pelo látex em amostras de soro positivas. CONCLUSÃO: O estudo permitiu demonstrar que o método imunoturbidimétrico e o método de aglutinação pelo látex são igualmente capazes de discriminar amostras negativas e positivas para FR.

Effect of serum sample inactivation on the performance of latex agglutination test for paracoccidioidomycosis serodiagnosis

Paracoccidioidomycosis is diagnosed from the direct observation of the causative agent, but serology can facilitate and decrease the time required for diagnosis. The objective of this study was to determine the influence of serum sample inactivation on the performance of the latex agglutination test (LAT) for detecting antibodies against Paracoccidioides brasiliensis. The sensitivity of LAT from inactivated or non-inactivated samples was 73% and 83%, respectively and the LAT selectivity was 79% and 90%, respectively. The LAT evaluated here was no more specific than the double-immunodiffusion assay. We suggest the investigation of other methods for improving the LAT, such as the use of deglycosylated antigen.

Disseminated cryptococcal lymphadenitis with negative latex agglutination test / 中华医学杂志(英文版)

We reported an unusual case of disseminated cryptococcal lymphadenitis in an immunocompetent host who presented with fever and lymphadenopathy, which were the only two symptoms and signs. Latex agglutination test of serum and cerebrospinal fluid (CSF) were negative, while lymph node biopsy showed Cryptococcus neoformans. A diagnosis of disseminated cryptococcal lymphadenitis was made. Then the patient was treated with amphotericin B for 15 days as initial therapy and itraconazole for 6 months as maintenance therapy respectively. The patient received re-examination per 6 months and was followed up for 2 years. Swollen lymph nodes diminished gradually, and no fever or other symptoms were found. Latex agglutination test of serum and CSF were negative throughout the follow-up period, and anti-HIV, syphilis and tuberculosis antibody were all negative.

Rotavirus infection in a tertiary hospital: laboratory diagnosis and impact of immunization on pediatric hospitalization

BACKGROUND AND OBJECTIVES: Rotavirus (RV) is the main etiological agent of diarrhea in childhood; its laboratory diagnosis is crucial to guide the clinical management and prevention of its spread. RV immunization was introduced in Brazilian 6-month-old children in 2006. The present study was aimed to evaluate three methodologies used for human RV detection in stool samples obtained from patients hospitalized due to gastroenteritis in a teaching hospital and report the impact of RV immunization in hospitalization by diarrhea. METHODS: 293 stool samples collected in the 2001-2008 period were analyzed by enzyme immunoassay (EIA), latex agglutination (LA) and polyacrylamide gel electrophoresis (PAGE). RESULTS: Rotavirus was detected in 34.8 percent of samples by LA assay, 28.3 percent of samples by EIA assay and in 25.6 percent of samples by PAGE assay. Considering the PAGE method as gold standard, the sensitivity, specificity and accuracy of EIA were 94.6 percent, 94.4 percent and 94.5 percent, and to LA were 82.6 percent, 81.6 percent and 81.9 percent, respectively. CONCLUSION: These results indicate that antigen detection by EIA is a rapid, sensitive and specific method, and could be used in large-scale applications for screening stool samples suspected of RV infection. This study showed decreased incidence of RV infection in hospitalized children prior to the implementation of the national immunization program against RV.