Comparative evaluation of fluorescence polarization assay and competitive ELISA for the diagnosis of bovine brucellosis vis-a-vis sero-monitoring.

Brucellosis is an important zoonosis that constitutes a serious public health hazard which is caused by a bacterium belonging to the genus Brucella. In the present study, two highly specific serological tests for brucellosis diagnosis, fluorescence polarization assay (FPA) and competitive ELISA (cELISA) were standardized in the laboratory, evaluated and compared with rose bengal plate test (RBPT), indirect ELISA (iELISA) and commercial cELISA kit. For test evaluation, 1386 serum samples [apparently healthy animals (n = 260), samples from Brucella infected farms (n = 701) and B. abortus S19 vaccinated animals (n = 425)] were analyzed to assess suitable diagnostic test in B. abortus S19 post vaccinated bovine population. In apparently healthy brucellosis free farms, RBPT, iELISA, in-house FPA and cELISA were found to be highly specific than commercial cELISA. Commercial cELISA kit was comparatively more sensitive than other serological tests in samples collected from infected farms. The FPA showed sensitivity nearly equal to RBPT and in-house cELISA showed greater sensitivity than RBPT in infected farms. In animals with persistent vaccinal antibodies, only in-house FPA and cELISA recorded higher specificity of 87.64 and 90.27%, respectively. The other tests, RBPT and iELISA displayed similar reactivity with vaccine antibodies to that of infection antibodies whereas commercial cELISA kit showed an intermediate specificity of 47.69%. With these findings, RBPT, iELISA and cELISA are suggested for screening infected herds, and in-house developed FPA and cELISA tests with a proven specificity can be used for confirmatory diagnosis of brucellosis in B. abortus S19 post vaccinated animal populations.

Identification of Brucella abortus biovar 4 of bovine origin in Colombia / Identificación de Brucella abortus biovar 4 de origen bovino en Colombia

The objective of this study was to identify twelve Brucella abortus isolates of bovine origin from the department of Nariño in Colombia up to the biovar level. These isolates are included in the collection of the Germplasm Bank of Microorganisms of Animal Health Interest -Bacteria and Virus (BGSA-BV). The identification was carried out through conventional methods such as macro and microscopic morphological descriptions, enzymatic activity, biochemical profile, substrate use and sensitivity to dyes. Complementary genotypic characterization was carried out using multiplex PCR for B. abortus, Brucella melitensis, Brucella ovis, and Brucella suis-Erytritol (AMOS-ERY-PCR), RFLP-IS711, by southern blot hybridization, as well as by the multiple locus variable number of tandem repeat analysis (MLVA) using the ery gene and the insertion sequence IS711 and variable number of tandem repeats (VNTR) as molecular markers. The results of the phenotypic and molecular characterization allowed to identify twelve isolates as B. abortus biovar 4 as well as to differentiate field from vaccine strains. This is the first study on the phenotypic and molecular identification of B. abortus isolates in Colombia. It was concluded that the phenotypic and molecular identification of twelve isolates as B. abortus biovar 4 could be achieved using conventional and molecular techniques with enough resolution power. The identification of these isolates to the biovar level in taxonomic and epidemiological terms will allow the use of this genetic resource as reference strains in future research. This finding constitutes the basis for identifying biotypes not previously reported in the country that might be useful to support brucellosis survey programs in Colombia.

El objetivo de este estudio fue identificar 12 aislamientos de Brucella abortus de origen bovino procedentes del departamento de Narino, Colombia, hasta la descripción de biovar. Estos aislamientos conforman la colección del Banco de Germoplasma de Microorganismos de Interés en Salud Animal, Bacterias y Virus. La identificación se hizo mediante métodos convencionales, como la descripción morfológica macro y microscópica de actividad enzimática, de perfiles bioquímicos, de utilización de sustratos y de sensibilidad a colorantes. Se hizo una caracterización genotipica complementaria mediante PCR múltiple para Brucella abortus, Brucella melitensis, Brucella ovisy Brucella suis-eritritol (AMOS-ERY-PCR); RFLP-/S7II; hibridación Southern blot y análisis multi-locus de repeticiones en tándem de número variable (MLVA), empleando como marcadores moleculares el gen ery, la secuencia de inserción /S711 y el número variable de repeticiones en tándem (VNTR). Los resultados de la caracterización fenotípica y molecular permitieron identificar 12 aislamientos de campo como B. abortus biovar 4 y diferenciar cepas de campo de cepas vacunales. Este es el primer estudio de identificación fenotípica y molecular de aislamientos de B. abortus en Colombia. Por su importancia taxonómica y epidemiológica, la identificación de estos aislamientos hasta el nivel de biovar permitirá disponer de recursos genéticos que se pueden emplear como cepas de referencia en futuras investigaciones. Estos resultados pueden considerarse como una base para la identificación de biotipos no reportados en el país y podrán ser utilizados en programas de monitoreo y vigilancia de la brucelosis bovina en Colombia.

Evaluation of dot-blot test for serological diagnosis of bovine brucellosis

Abstract The objective of this study was to standardize and validate the dot-blot test for the serological diagnosis of bovine brucellosis, compare the results with those found in the 2-mercaptoethanol (2-ME) and complement fixation test (CF), and estimate the relative sensitivity and specificity of the dot-blot compared to these tests. Fifty bovine blood serum samples were used for the test standardization, and 1315 samples were used for evaluation and comparison between the tests; the results were compared using the Kappa indicator. At the end of standardization, it was established as optimal for the antigen obtained from Brucella abortus B19 after passing through a microorganism rupture process, the blood serum samples diluted at 1:100, and the conjugate at 1:30,000. The comparison of the dot-blot results with 2-ME showed Kappa index of 0.9939, sensitivity of 99.48%, and specificity 99.91%, with CF, Kappa index of 0.8226, sensitivity 100% and specificity 95.32%. Using the combination of the test results 2-ME and CF to establish the true condition of the animal, the dot-blot showed relative sensitivity of 100%, and relative specificity of 99.91%. The evaluated test proved to be effective and reliable, besides being easy to handle and interpret the results.

Brucellosis in water buffaloes / Brucelose em bubalinos

The domestication of water buffaloes (Bubalus bubalis) originated in India and China and spread throughout the world and represents an important source of food of high biological value. Given the importance and relevance of brucellosis for buffalo production, this article reviews the history, etiopathogenesis, epidemiology, clinical signs, anatomopathological findings, diagnosis and control of the disease, focusing on data from studies on water buffaloes performed in different countries and the Brazilian Amazon biome.(AU)

A domesticação do búfalo (Bubalus bubalis) ocorreu particularmente na Índia e China, difundindo-se pelo mundo, gerando fontes de alimento de alto valor biológico. Diante da importância e relevância da brucelose para a bubalinocultura este trabalho tem por objetivo fazer uma revisão acerca do histórico da doença, etiopatogenia, fatores epidemiológicos, sinais clínicos, achados anatomopatológicos, diagnóstico e o controle, com enfoque nos dados obtidos em estudos em bubalinos no mundo e no Bioma Amazônico brasileiro.(AU)

Brucella abortus detected in cheese from the Amazon region: differentiation of a vaccine strain (B19) from the field strain in the states of Pará, Amapá and Rondônia, Brazil / Brucella abortus em queijos na região amazônica: diferenciação em cepa vacinal (B19) ou de infecção a campo nos estados do Pará, Amapá e Rondônia

Brucellosis is an infectious-contagious disease responsible for significant economic losses to the meat and milk supply chain, because it causes reproductive disorders in animals and is a chronic anthropozoonosis. This study was designed to detect the DNA of Brucella spp. in cheese and to differentiate between a vaccine strain (B19) and the field strain. Sixty-six samples of different cheeses which are produced and marketed in three states of the Brazilian Amazon region (Amapá [5 samples], Pará [55 samples] and Rondônia [6 samples]) were evaluated. Thirty-nine of these samples were from cheeses made from cow's milk, and 27 were from cheeses made from buffalo milk. Four of the 66 samples were from cheeses produced in milk processing plants regulated by the Federal Inspection Service (Serviço de Inspeção Federal); nine of the samples were from cheeses produced in processing plants regulated by the State Inspection Service (Serviço de Inspeção Estadual); five of the samples were from artisanal cheeses; and the remaining 48 samples were from informally produced cheese. DNA was obtained from the samples following a DNA extraction protocol, and PCR was conducted using primers B4 and B5 to detect Brucella spp. Primers eri1 and eri2 were used to differentiate the field strain from the B19 vaccine strain. The results showed that 21.21% (14/66) of the samples were positive for Brucella spp., of which 21.43% (3/14) were positive for the B. abortus field strain, and 7.14% (1/14) were identified as harboring vaccine strain B19. These results demonstrate that it is possible to identify Brucella spp. in cheese from the Amazon region using the PCR technique and to differentiate the B. abortus field strain from the B19 vaccine strain.(AU)

A brucelose é uma enfermidade infecto-contagiosa que causa grandes perdas econômicas à cadeia produtiva da carne e do leite, como consequência dos distúrbios reprodutivos nos animais, além de ser uma antropozoonose crônica. O objetivo deste estudo foi detectar DNA de Brucella spp. e fazer a distinção da cepa vacinal (B19) da cepa de infecção de campo. Foram adquiridas 66 amostras de diferentes queijos produzidos e comercializados em três estados pertencentes à Amazônia brasileira: Amapá (05), Pará (55) e Rondônia (06), somando 39 amostras de queijo de vaca e 27 de búfala. Deste total quatro eram produzidas em estabelecimentos com fiscalização de Serviço de Inspeção Federal, nove em estabelecimentos com Serviço de Inspeção Estadual, cinco eram de produção artesanal e as demais 48 amostras eram provenientes de produção informal. O DNA das amostras teste foi obtido por um protocolo de extração e a reação em cadeia pela polimerase foi realizada utilizando os oligoiniciadores B4 e B5 para detectar Brucella spp. e, os oligoiniciadores eri1 e eri2 para diferenciar cepa de infecção a campo da cepa vacinal B19. Os resultados mostraram que 21,21% (14/66) das amostras foram positivas para Brucella spp., destas 21,43% (3/14) foram positivas para B. abortus cepa de campo e 7,14% (1/14) foi identificada como cepa vacinal B19. Concluiu-se que foi possível identificar pela técnica da PCR Brucella spp. em queijos na região amazônica, além de diferenciar as cepas em amostra de B. abortus de infecção a campo ou cepa vacinal B19.(AU)

A case of unusual septic knee arthritis with Brucella abortus after arthroscopic meniscus surgery.

We present a 51-year-old male patient with Brucella abortus septic arthritis in the right knee following arthroscopic meniscus surgery. He had eaten a traditional dish of raw minced cattle conceptus (bovine fetus) that was prepared after the cow was slaughtered. Despite treatment with empirical antibiotics and debridement of the postoperative surgical wound, the infection persisted without improvement. Polymerase chain reaction sequencing identified Brucella abortus from tissue samples obtained from the patient. After confirmation of the diagnosis of brucellar infection, antibiotics were replaced with doxycycline and rifampin, which were used for 4 months. In patients with a non-specific arthralgia who eat raw meat or live close to animals, it is important to consider the possibility of septic arthritis due to infection with Brucella spp.

Brucella abortus mutants lacking ATP-binding cassette transporter proteins are highly attenuated in virulence and confer protective immunity against virulent B. abortus challenge in BALB/c mice.

Brucella abortus RB51 is an attenuated vaccine strain that has been most frequently used for bovine brucellosis. Although it is known to provide good protection in cattle, it still has some drawbacks including resistance to rifampicin, residual virulence and pathogenicity in humans. Thus, there has been a continuous interest on new safe and effective bovine vaccine candidates. In the present study, we have constructed unmarked mutants by deleting singly cydD and cydC genes, which encode ATP-binding cassette transporter proteins, from the chromosome of the virulent Brucella abortus isolate from Korean cow (referred to as IVK15). Both IVK15ΔcydD and ΔcydC mutants showed increased sensitivity to metal ions, hydrogen peroxide and acidic pH, which are mimic to intracellular environment during host infection. Additionally, the mutants exhibited a significant growth defect in RAW264.7 cells and greatly attenuated in mice. Vaccination of mice with either IVK15ΔcydC or IVK15ΔcydD mutant could elicit an anti-Brucella specific immunoglobulin G (IgG) and IgG subclass responses as well as enhance the secretion of interferon-gamma, and provided better protection against challenge with B. abortus strain 2308 than with the commercial B. abortus strain RB51 vaccine. Collectively, these results suggest that both IVK15ΔcydC and IVK15ΔcydD mutants could be an attenuated vaccine candidate against B. abortus.

Detecção de Brucella abortus em linfonodos de búfalas (Bubalus bubalis) em diferentes fases da gestação / Detection of Brucella abortus in lymph nodes of buffalo cows (Bubalus bubalis) at different stages of pregnancy

O objetivo do presente trabalho foi verificar a presença do DNA de Brucella abortus e caracterizar as lesões causadas por esse agente em linfonodos de búfalas. Foram utilizadas 19 búfalas em diversos estágios de gestação, sorologicamente positivas para brucelose, submetidas ao abate sanitário, das quais se coletou fragmentos de diversos linfonodos. A idade fetal foi determinada através de exames ultrassonográficos associados à mensuração dos fetos durante a necropsia. Amostras foram coletadas e submetidas à qPCR e histopatologia. A detecção de DNA de B. abortus nos linfonodos das búfalas avaliadas foi verificada a partir do quarto mês de gestação em sete búfalas e em uma búfala pós-parição. Os achados histológicos foram linfadenite aguda a crônica. A presença de DNA de B. abortus foi detectada em todos os grupos de linfonodos avaliados, sendo que os linfonodos mais acometidos foram os mamários...

The objective of this study was to detect Brucella abortus in lymph nodes of buffaloes as well as to describe the lesions caused. Nineteen buffalo cows in various stages of pregnancy, serologically positive for brucellosis and subjected to culling were used. Fetal age was determined by ultrasound examination and the size of fetuses was measured at necropsy. Fragments of lymph nodes were collected for histopathology and qPCR. The detection of B. abortus DNA in the lymph nodes was checked from the fourth month of pregnancy in seven buffaloes and in a post-calving buffalo. Acute to chronic lymphadenitis was histologically diagnosed. B. abortus DNA was detected in all evaluated groups of lymph nodes; the mammary lymph nodes were the most affected...

Infecção transplacentária e intrauterina por Brucella abortus em búfalos (Bubalus bubalis) / Placenta and intrauterine infection by Brucella abortus in buffaloes (Bubalus bubalis)

O objetivo deste trabalho foi verificar a presença de Brucella abortus e as lesões causadas por esse agente nos anexos fetais e nos fetos de búfalas. Para isso, 20 búfalas em diversos meses de gestação, sorologicamente positivas para brucelose, foram submetidas ao abate sanitário. A idade fetal foi determinada através de exames ultrassonográficos associados à mensuração dos fetos durante a necropsia. Do útero fechado desses animais foram coletadas amostras para histopatologia e qPCR. A partir do segundo mês de gestação foi possível detectar a presença de DNA de B. abortus em líquido amniótico, líquido alantoide e em útero e, a partir do quinto mês, na placenta, coração, baço, rim, pulmão, intestino, fígado e linfonodos dos fetos. Os principais achados anatomopatológicos foram placentite fibrinopurulenta necrótica e endometrite supurativa crônica...

The objective of this study was to detect Brucella abortus and injuries caused by the bacteria in fetal membranes and fetuses. Twenty buffaloes serologically positive for brucellosis were used and subjected to stamping for collection of material from the closed uterus of several months gestation. Fetal age was determined by ultrasound examination and the size of fetuses was measured at necropsy. The samples were subjected to histopathology and qPCR. From the second month of pregnancy on it was possible to detect the presence of B. abortus DNA in amniotic fluid, allantoic liquid and uterus, and from the fifth month on in placenta, heart, spleen, kidney, lung, intestine, liver and lymph nodes of the fetuses. The main pathological findings were fibrinous suppurative necrotic placentitis, and chronic endometritis...

Different resistance patterns of reference and field strains of Brucella abortus

The aim of this study was to evaluate the growth of the B. abortus reference strains and field isolates on media containing different inhibitor agents. Reference strains were seeded on tryptose agar containing: i-erythritol (1.0 mg/mL), fuchsin (20 μg/mL and 80 μg/mL), thionin (2.5 μg/mL and 10 μg/mL), rifampicin (200 μg/mL) and safranin O (200 μg/mL). Field isolates were tested only on media containing i-erythritol, rifampicin and thionin. Furthermore, each suspension was also inoculated on tryptose agar incubated in air, to test its ability to grow without CO2. Sensitivity to fuchsin was similar among reference strains evaluated. Growth of S19, 544 and 2308 but not RB51 were inhibited on media containing rifampicin. Medium with safranin O showed no inhibition for RB51, 544 and 2308, but it partially inhibited the S19 growth as well as medium containing i-erythritol. Treatment/control growth ratio for 2308 on tryptose agar containing thionin (2.5 μg/mL) was approximatelly 1.0, whereas S19 and RB51 showed 0.85 and 0.89 ratios, respectively. Growth of 544, S19 and RB51 but not 2308 was completely inhibited on medium with thionin (10 μg/mL). All field strains grew on medium containing i-erythritol, but were completelly inhibited by rifampicin. With exception of A1 (B. abortus biovar 3) all field isolates grew on medium with thionin, although some strains showed a treatment/control growth ratio of 0.75–0.80 (10 μg/mL). These results showed that tryptose agar with thionin, i-erythritol or rifampicin could be useful for differentiating vaccine, challenge and field strains of B. abortus.

Failure of total hip arthroplasty secondary to infection caused by Brucella abortus and the risk of transmission to operative staff.

Infection of total knee or hip arthroplasty by Brucella species is a rare complication. We describe the case of a failed hip replacement secondary to infection by Brucella abortus, as well as presentation, treatment course, and 2-year follow-up. In addition, we review the literature for features of periprosthetic Brucella species infections, and we describe the common exposures, clinical presentations, preoperative evaluation, and treatments used in the reported cases. Furthermore, we discuss the risk of transmission to operating room personnel and the appropriate preventative measures to avoid transmission.

Caracterização morfológica e imuno-histoquímica de lesões em casos de aborto bovino bacteriano e viral no sul de Minas Gerais / Morphological and immunohistochemical characterization of the lesions in cases of bacterial and viral bovine abortion in southern Minas Gerais, Brazil

O presente estudo avaliou a participação de agentes bacterianos e virais em abortos em bovinos de propriedades rurais do sul de Minas Gerais. Foi realizada análise histopatológica e imuno-histoquímica dos casos de aborto recebidos pelo Setor de Patologia Veterinária da Universidade Federal de Lavras no período de 1999 a 2013. De 60 fetos analisados, em 30 (50%) foram observadas lesões microscópicas. Destes, oito apresentavam lesões compatíveis com infecção por agentes bacterianos e três apresentaram lesões sugestivas de agentes virais. Dos abortos bacterianos, um feto tinha lesões compatíveis com leptospirose, caracterizadas por icterícia e colestase, nefrite intersticial linfoplasmocítica e nefrose tubular. Sete fetos apresentaram pneumonia ou broncopneumonia purulenta; num deles havia também pleurite e peritonite fibrinosas; e em dois desses fetos houve imunomarcação para Brucella abortus. Dos três fetos com lesões sugestivas de aborto viral ocorreu imunomarcação anti-Herpesvírus bovino em um. Os resultados demonstram a ocorrência de abortos de origem bacteriana e viral na Região do estudo e que medidas profiláticas devem ser adotadas nas propriedades. O trabalho demonstra também que a imuno-histoquímica (IHQ); associada à histopatologia; é uma ferramenta útil e viável para o diagnóstico, especialmente quando provas microbiológicas e/ou sorológicas não estão disponíveis.

The paper evaluates the participation of bacterial and viral agents in bovine abortions in farms of southern Minas Gerais state, Brazil. Histopathological and immunohistochemical analysis was performed in aborted fetuses of cattle received by the Setor de Patologia Veterinária, Universidade Federal de Lavras, from 1999 to 2013. From 60 fetuses studied, 30 (50%) had microscopic lesions. From these, eight had lesions consistent with bacterial agents and three had lesions suggestive of viral agents. In the bacterial abortions, one fetus presented lesions compatible with leptospirosis, characterized by jaundice, cholestasis, lymphoplasmacytic intersticial nephritis, and tubular nephrosis. Seven fetuses had purulent pneumonia or bronchopneumonia and one of them had also fibrinous pleuritis and peritonitis; two of them presented positive immunostaining for Brucella abortus. One of the three fetuses with lesions of viral infection revealed positive imunostaining for bovine herpesvirus. The results showed that abortions of bacterial and viral origin occur in the Region of this study and prophylactic measures should be adopted on the farms. This study also demonstrates that immunohistochemistry associated with histopathology is a useful and viable tool for the diagnosis, especially when microbiological and/or serological tests are not available.

Molecular detection of Brucella species in patients suspicious of Brucellosis from Zanjan, Iran

Brucella is an intracellular pathogen capable of infecting animals and humans. The aim of this study was to identify Brucella spp in sera of high risk individuals by a polymerase chain reaction (PCR)-based method. A total of 180 patients suspected to have Brucellosis were examined by serological tests. To establish a PCR protocol for diagnosis of active brucellosis, DNA was extracted from the serum samples by using a commercial kit. PCR amplification was done for detection of Brocella DNA using BCSP31 target gene and IS711 locus. The PCR assay showed that an amplicon of 223 bp was obtained in 73.8% (133/180) of the tested sera using primers (B4/B5) derived from a gene encoding the 31-kDa Brucella abortus antigen. In another PCR, an amplicon of 498 bp was obtained in 63.8% (115/180) of the samples using Brucella abortus-specific primers derived from a locus adjacent to the 3'-end of IS711, and also an amplicon of 731 bp was produced in 4.4% (8/180) of the tested samples using Brucella melitensis-specific primers. When the Wright method was used as a gold standard, the sensitivity and specificity of the PCR technique for genus identification were found to be 96 and 80.7%, respectively. However, the sensitivity value obtained with the species-specific PCR method was 82%, and specificity was similar to that previous reported. This is the first report of a high frequency of Brucella abortus in patients suspicious of Brucellosis from the Zanjan province.

Detecção de Brucella abortus em tecidos bovinos utilizando ensaios de PCR e qPCR / Detection of Brucella abortus in bovine tissue using PCR and qPCR

Objetivou-se no presente estudo avaliar as técnicas reação em cadeia da polimerase (PCR) e PCR em Tempo Real (qPCR) para detectar Brucella abortus, a partir de tecidos bovinos com lesões sugestivas de brucelose. Para isto, 21 fragmentos de tecidos bovinos coletados em abatedouros de Mato Grosso do Sul foram processados e submetidos ao cultivo microbiológico e extração do DNA genômico para realização das reações de PCR e qPCR. No cultivo microbiológico, oito amostras apresentaram crescimento bacteriano e cinco foram confirmadas como B. abortus por PCR. Diretamente das amostras de tecido, DNA do gênero Brucella (oligonucleotídeos IS711) foi detectado em 13 (61,9 por cento) amostras de tecido e 17 (81 por cento) amostras de homogeneizado. Já com os oligonucleotídeos espécie-específicos BruAb2_0168F e BruAb2_0168R, 14 (66 por cento) amostras de tecido e 18 (85,7 por cento) amostras de homogeneizado foram amplificadas. Seis amostras positivas na PCR espécie-específica foram sequenciadas e o best hit na análise BLASTn foi B. abortus. Na qPCR, 21 (100 por cento) amostras de tecidos e 19 (90,5 por cento) amostras de homogeneizado foram positivas para B. abortus. Dez amostras de DNA de sangue bovino de rebanho certificado livre foram utilizadas como controle negativo nas análises de PCR e qPCR utilizando-se os oligonucleotídeos BruAb2_0168F e BruAb2_0168R. Na PCR nenhuma amostra amplificou, enquanto que na qPCR 2 (20 por cento) amplificaram. Conclui-se que as duas técnicas detectam a presença de B. abortus diretamente de tecidos e homogeneizados, porém a qPCR apresentou maior sensibilidade. Os resultados obtidos indicam que a qPCR pode representar uma alternativa rápida e precisa para a detecção de B. abortus diretamente de tecidos, e ser utilizada em programas de vigilância sanitária, por apresentar sensibilidade e especificidade satisfatórias.

The aim of the study was to evaluate the technical polymerase chain reaction (PCR) and Real-Time PCR (qPCR) to detect Brucella abortus from bovine tissues with suggestive lesions of brucellosis. For this, 21 fragments of bovine tissues collected at abattoirs of Mato Grosso do Sul were processed and subjected to microbiological culture and extraction of genomic DNA to perform the PCR reactions and qPCR. Eight samples of microbiological culture showed bacterial growth and five samples were confirmed as B. abortus by PCR. DNA of Brucella (IS711 primers) was detected in 13 (61.9 percent) directly from tissue samples and 17 (81 percent) from tissue homogenate samples. With the species-specific set of primers BruAb2_0168F and BruAb2_0168R, 14 (66 percent) tissue samples and 18 (85.7 percent) tissue homogenate samples were positive. Six positive samples in the species-specific PCR were sequenced and the best hit in the BLASTn analysis was B. abortus. By qPCR, 21 (100 percent) tissue samples and 19 (90.5 percent) tissue homogenate samples were positive for B. abortus. Ten samples of DNA from bovine blood from an accredited-free herd were used as negative control in PCR and qPCR analysis using the primers BruAb2_0168F and BruAb2_0168R, and no one amplified by PCR, whereas two samples were amplified by qPCR (20 percent). In conclusion, both techniques detect the presence of B. abortus directly from tissues and homogenized, but the qPCR showed high sensitivity. The results indicate that qPCR can represent an alternative tool for faster and more accurate detection of B. abortus directly from tissues, and use in health surveillance programs by presenting satisfactory sensitivity and specificity.

Deletion in the gene BruAb2_0168 of Brucella abortus strains: diagnostic challenges.

Three Brucella abortus strains were isolated from joint hygromas from cows in northern Togo. Two deletions in the 5' side of the gene BruAb2_0168 were identified. As this gene is used for species identification, these deletions have consequences for diagnostic procedures. Multiple locus variable number of tandem repeat (VNTR) analysis was therefore performed for species identification. The strains showed unique VNTR profiles, providing some of the first genotypic data from West Africa. More molecular and epidemiological data are needed from the region, in order to better understand transmission patterns and develop suitable diagnostic assays.

Examination of taxonomic uncertainties surrounding Brucella abortus bv. 7 by phenotypic and molecular approaches.

Brucella taxonomy is perpetually being reshuffled, at both the species and intraspecies levels. Biovar 7 of Brucella abortus was suspended from the Approved Lists of Bacterial Names Brucella classification in 1988, because of unpublished evidence that the reference strain 63/75 was a mixture of B. abortus biovars 3 and 5. To formally clarify the situation, all isolates previously identified as B. abortus bv. 7 in the AHVLA and ANSES strain collections were characterized by classical microbiological and multiple molecular approaches. Among the 14 investigated strains, including strain 63/75, only four strains, isolated in Kenya, Turkey, and Mongolia, were pure and showed a phenotypic profile in agreement with the former biovar 7, particularly agglutination with both anti-A/anti-M monospecific sera. These results were strengthened by molecular strategies. Indeed, genus- and species-specific methods allowed confirmation that the four pure strains belonged to the B. abortus species. The combination of most approaches excluded their affiliation with the recognized biovars (biovars 1 to 6 and 9), while some suggested that they were close to biovar 3.These assays were complemented by phylogenetic and/or epidemiological methods, such as multilocus sequence analysis (MLSA) and variable-number tandem repeat (VNTR) analysis. The results of this polyphasic investigation allow us to propose the reintroduction of biovar 7 into the Brucella classification, with at least three representative strains. Interestingly, the Kenyan strain, sharing the same biovar 7 phenotype, was genetically divergent from other three isolates. These discrepancies illustrate the complexity of Brucella taxonomy. This study suggests that worldwide collections could include strains misidentified as B. abortus bv. 7, and it highlights the need to verify their real taxonomic position.

[Comparison of effectiveness between two surgical methods in treatment of thoracolumbar brucella spondylitis].

OBJECTIVE: To compare the effectiveness between the method of simple posterior debridement combined with bone grafting and fusion and internal fixation and the method of one-stage anterior radical debridement combined with bone grafting and fusion and posterior internal fixation in the treatment of thoracolumbar brucella spondylitis so as to provide the reference for the clinical treatment. METHODS: A retrospective analysis was made on the clinical data of 148 cases of thoracolumbar brucella spondylitis between January 2002 and January 2012. Simple posterior debridement combined with bone grafting and fusion and internal fixation was used in 78 cases (group A), and one-stage anterior radical debridement combined with bone grafting and fusion and posterior internal fixation in 70 cases (group B). There was no significant difference in gender, age, disease duration, involved vertebral segments, erythrocyte sedimentation rate (ESR), visual analogue scale (VAS) score, neural function grade of America Spinal Injury Association (ASIA), and kyphosis Cobb angle before operation between 2 groups (P > 0.05). The peri operation period indexes (hospitalization time, operation time, and intraoperative blood loss) and the clinical effectiveness indexes (VAS score, ASIA grade, Cobb angle, and ESR) were compared; the bone fusion and the internal fixation were observed. RESULTS: Incision infection and paravertebral and/or psoas abscess occurred in 2 and 3 cases of group A respectively. All incisions healed by first intention and 2 cases had pneumothorax in group B. The operation time and the hospitalization time of group A were significantly shorter than those of group B (P < 0.05), and the intraoperative blood loss of group A was significantly lower than that of group B (P < 0.05). All of the cases in 2 groups were followed up 14- 38 months, 25 months on average. The VAS, ESR, and Cobb angle were significantly decreased at each time point after operation when compared with preoperative ones in 2 groups (P < 0.05), but no significant difference was found between 2 groups (P > 0.05). The neurological function was significantly improved at 3 months after operation; there were 1 case of ASIA grade C, 14 cases of grade D, and 63 cases of grade E in group A, and there were 1 case of grade C, 11 cases of grade D, and 58 cases of grade E in group B; and difference was not significant (Z = 0.168, P = 0.682). The grafting bone fusion was observed in both groups. The fusion time was (8.7 ± 0.3) months in group A and (8.6 ± 0.4) months in group B, showing no significant difference (t = 0.591, P = 0.601) was found. At last follow-up, no loosening or fracture of internal fixation was found. CONCLUSION: Based on regular medicine therapy, the effectiveness of the two methods is satisfactory in the treatment of thoracolumbar brucella spondylitis as long as the operation indications should be controlled strictly.

Detection of Brucella abortus DNA and RNA in different stages of development of the sucking louse Haematopinus tuberculatus.

BACKGROUND: Brucellosis is considered the world's most widespread zoonotic infection. It causes abortion and sterility in livestock leading to serious economic losses and has even more serious medical impact in humans, since it can be a trigger to more than 500,000 infections per year worldwide. The aim of this study was to evaluate the role of Haematopinus tuberculatus, a louse that can parasitize several ruminants, as a new host of brucellosis. Louse specimens were collected from seropositive and seronegative water buffaloes and divided in 3 developmental stages: adults, nymphs and nits. All samples were separately screened for Brucella spp. DNA and RNA detection by Real Time PCR. In particular, primers and probes potentially targeting the 16S rRNA and the Brucella Cell Surface 31 kDalton Protein (bcsp31) genes were used for Real Time PCR and buffalo ß actin was used as a housekeeping gene to quantify host DNA in the sample. A known amount of B. abortus purified DNA was utilized for standard curve preparation and the target DNA amount was divided by the housekeeping gene amount to obtain a normalized target value. A further molecular characterization was performed for Brucella strain typing and genotyping by the Bruce-ladder, AMOS-PCR and MLVA assays. Data were statistically analysed by ANOVA. RESULTS: Brucella abortus DNA and RNA were detected in all developmental stages of the louse, suggesting the presence of viable bacteria. Data obtained by MLVA characterization support this finding, since the strains present in animals and the relative parasites were not always identical, suggesting bacterial replication. Furthermore, the detection of Brucella DNA and RNA in nits samples demonstrate, for the first time, a trans-ovarial transmission of the bacterium into the louse. CONCLUSIONS: These findings identified H. tuberculatus as a new host of brucellosis. Further studies are needed to establish the role of this louse in the epidemiology of the disease, such as vector or reservoir.

Detección de un complejo clonal con el genotipo de Brucella abortus biovariedad 2 como fundador en aislamientos de B. abortus de Argentina / Detection of a clonal complex with Brucella abortus biovar 2 genotype as founder in B. abortus isolates from Argentina

Brucella abortus es el agente causal de la brucelosis bovina, enfermedad zoonótica que se encuentra ampliamente distribuida en el mundo. Actualmente existen ocho biovariedades de B. abortus. En Argentina se encuentra con mayor frecuencia la biovariedad 1, pero también se suele aislar la biovariedad 2, que es más patogénica que la anterior. Resulta necesario contar con métodos de tipificación que tengan la resolución suficiente para permitir el seguimiento epidemiológico de los brotes de brucelosis y de los programas de control de la enfermedad. Debido a la gran homogeneidad genética que existe entre las distintas especies del género Brucella, ha sido dificultoso el desarrollo de herramientas moleculares para realizar el análisis epidemiológico de los aislamientos. La publicación del genoma de varias especies de Brucella facilitó el diseño de estas herramientas. El objetivo del presente trabajo fue emplear un esquema de análisis multilocus de VNTR en aislamientos de Argentina obtenidos en nuestro laboratorio. De los 56 aislamientos analizados se obtuvieron 47 perfiles genotípicos diferentes. El empleo de este esquema permitió asignarles a dichos aislamientos la biovariedad correspondiente. A través del análisis goeBURST se pudo relacionar a todos los genotipos entre sí, y además, proponer al genotipo de la biovariedad 2 como fundador.

Brucella abortus is the causative agent of bovine brucellosis, a worldwide zoonosis. Up to date, eight biovars of B. abortus have been described. In Argentina, biovar 1 is the most frequently isolated. However, biovar 2, which is more pathogenic than biovar 1, is also found. Molecular methods for subtyping isolates are necessary for allowing epidemiological surveillance and control of eradication programs. Due to the genetic homogeneity of the genus Brucella, the development of molecular typing tools has been difficult. The publication of microorganism genomes facilitates the design of this approach. The aim of this work was to employ a Multiple Locus VNTR Analysis (MLVA) scheme for strains from Argentina isolated in our laboratory. From the 56 isolates analyzed, 47 different genotypic profiles were obtained. All the strains typed as biovar 2 showed the same profile. This scheme allowed assigning each isolate to the biovar it belongs to. All the genotypes were related using the goeBURST analysis and biovar 2 was proposed as founder.

Renal cyst infection caused by Brucella abortus.

A 49-year-old man with a medical history of polycystic kidney disease was presented to the emergency department with fever and left flank pain. Abdominal examination revealed an enlarged and painful left kidney. The C-reactive protein level was significantly high and the magnetic resonance imaging revealed areas of abnormal intensity and fluid-fluid levels in renal cysts. Brucella abortus was yielded from both blood and cyst fluid culture. Standard therapy (rifampicin plus doxycycline) of brucellosis was started, but the clinical and laboratory signs subsided after the addition of ciprofloxacin. There was no need for aspiration of infected cyst fluid. Hereby, according to the medical database search, we report that the first renal cyst infection caused by B. abortus was successfully treated with triple antibiotic therapy.