Preliminary study of an immunochromatography test for serological diagnosis of canine brucellosis.

The most widely used screening test for the diagnosis of brucellosis in the dog is the rapid slide agglutination test in the presence of 2-mercaptoethanol (2ME-RSAT). The diagnosis is partially confirmed by the agar gel immunodiffusion test (AGID) and definitively confirmed by bacteriological isolation. Some chronic cases not detected by these tests may be detected by ELISA tests. The use of 2ME-RSAT in routine clinical practice requires a microscope and an experienced operator. An immunochromatographic diagnostic test for canine brucellosis (FASTest(®) Brucella c., Megacor, Hörbranz, Austria) has been recently released. In this study, we compared the diagnostic performance of the FASTest with those of 2ME-RSAT, AGID and ELISAs. Sera from 17 healthy dogs used as negative controls yielded negative results by FASTest, indicating a 100% specificity in this sample. Among 27 sera of dogs with acute or subacute brucellosis confirmed by B. canis isolation, all of which were positive by RSAT and ELISAs, the FASTest was positive in 24 cases and AGID in 23. In acute and subacute cases, the sensitivity of FASTest was 89%. Sera from six dogs with bacteriologically confirmed chronic brucellosis, which were positive by ELISAs but negative by 2ME-RSAT, were also tested; 1 was positive by FASTest and 4 were positive by AGID. These preliminary results indicate a good specificity of the FASTest (100% in this sample) but an unacceptable sensitivity as a screening test. In cases with chronic brucellosis, the sensitivity of the FASTest was lower than that of ELISAs but this assay could make a good intermediate test to be run after a positive RSAT and before running an AGID.

Identification of Corynebacterium pseudotuberculosis from sheep by PCR-restriction analysis using the RNA polymerase ß-subunit gene (rpoB).

Caseous lymphadenitis, caused by Corynebacterium pseudotuberculosis, has a high prevalence in many regions of the world, including Argentina and Brazil. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for the identification of this microorganism was designed based on the hypervariable region of the polymorphic RNA polymerase ß-subunit gene (rpoB). All available CorynebacteriumrpoB sequences were analyzed by computer-assisted restriction analysis. The rpoB PCR-RFLP pattern predicted by using endonucleases MseI and StuI clearly differentiated C. pseudotuberculosis from sixty-one other Corynebacterium species. This method was successfully applied to identify twelve wild C. pseudotuberculosis ovine isolates and one caprine isolate. It was also used to differentiate C. pseudotuberculosis from Arcanobacterium pyogenes, an ovine pathogen with similar clinical characteristics. These results indicate that this new molecular method can be used for the reliable identification of the pathogen, essential for the timely detection of infected animals and for epidemiological studies.

Lupus eritematoso sistémico inducido por interferón-α pegilado en un paciente con infección por VHC / Pegylated interferon-α induced lupus in a patient with chronic hepatitis C

El Lupus inducido por drogas tiene una prevalencia estimada del 10%, debe sospecharse frente al antecedente de la exposición a un farmaco y están relacionado en forma temporal al uso del mismo. Generalmente, luego de suspender la droga el cuadro se resuelve. El Interferón-α puede ser responsable tanto de gatillar una respuesta inmune en pacientes predispuestos como de exacerbarla en aquellos con patologías autoinmunes previas. Comunicamos el caso de un varón de 54 años con infección por virus de hepatitis C que desarrolló LES inducido por IFN-α pegilado y realizamos una revisión de la literatura.(AU)

Lupus eritematoso sistémico inducido por interferón-α pegilado en un paciente con infección por VHC / Pegylated interferon-α induced lupus in a patient with chronic hepatitis C

El Lupus inducido por drogas tiene una prevalencia estimada del 10%, debe sospecharse frente al antecedente de la exposición a un farmaco y están relacionado en forma temporal al uso del mismo. Generalmente, luego de suspender la droga el cuadro se resuelve. El Interferón-α puede ser responsable tanto de gatillar una respuesta inmune en pacientes predispuestos como de exacerbarla en aquellos con patologías autoinmunes previas. Comunicamos el caso de un varón de 54 años con infección por virus de hepatitis C que desarrolló LES inducido por IFN-α pegilado y realizamos una revisión de la literatura.

[Molecular study of Argentine strains of Bacillus anthracis]. / Estudio molecular de cepas argentinas de Bacillus anthracis.

Bacillus anthracis is one of the most monomorphic bacteria known and epidemiological studies of this microorganism have been hampered by the lack of molecular markers. For the genotyping of fourteen Argentine field strains and the vaccine strain Steme 34F2 the presence or absence of the virulence plasmids as well as vrrA locus containing a variable-number tandem repeat (VNTR) and presenting a polymorphism involving five variants, were analyzed. Strains were isolated from cows, sheep and pigs during outbreaks occurred in Buenos Aires, Entre Ríos, Santa Fe and La Pampa in the past fifty years. All of the field strains presented plasmids pXO1 and pXO2, except for a strain isolated from pig that only presented plasmid pXO2. All the strains and the vaccine strain belonged to the same VNTR variant that was defined by sequencing the vrrA locus from three of the isolates and the strain 34F2. These sequences were completely identical and corresponded to the variant VNTR4. Thus, the fourteen Argentine B. anthracis strains studied showed great uniformity at molecular level even though they had been isolated from different mammal species within a wide time period and covering an extensive geographical area.

[Molecular characterization of Brucella abortus strain 19 and its application for controlling biologics]. / Tipificación molecular de Brucella abortus cepa 19 y su aplicación al control de biológicos.

Brucella abortus is the etiological agent of bovine brucellosis. The strain 19 used in vaccine elaboration can be identified through a deletion in the eri region associated with its susceptibility to erythritol. We optimized a PCR assay for specific characterization of this strain. The method described here is a rapid procedure that enables identification of B. abortus, and simultaneous differentiation of the strain 19 from other B. abortus biovar 1 strains. We applied the assay to detect the strain 19 in vaccines against B. abortus produced in Argentina. Thq results show this method could be used to follow vaccine seed cultures of this strain. The methodology could also contribute to reduce the risk of a laboratory-acquired infection and could be of great help as a routine test for confirmation of B. abortus in non related vaccines.

Tipificación molecular de Brucella abortus cepa 19 y su aplicación al control de biológicos / Molecular characterization of Brucella abortus strain 19 and its application for controlling biologics

Brucella abortus es el agente etiológico de la brucelosis bovina. La cepa 19, utilizada en la elaboración de vacunas, puede ser identificada a través de una deleción en la región eri asociada con la sensibilidad al eritritol. Se optimizó un ensayo de PCR para caracterizar específicamente esta cepa. El método que describimos es un procedimiento rápido para identificar B. abortus y simultáneamente diferenciar la cepa 19 de otras cepas de B. abortus biovar 1. Hemos aplicado este ensayo para la detección de la cepa 19 en vacunas contra la brucelosis bovina elaboradas en Argentina. Los resultados indican que este método podría ser útil para el seguimiento de las cepas madres y semillas utilizadas en la producción industrial de esta vacuna. Esta metodología también contribuiría a la reducción del riesgo de la infección adquirida en el laboratorio y podría aplicarse como prueba de rutina para confirmar la presencia de B. abortus en vacunas no relacionadas.

Brucella abortus is the etiological agent of bovine brucellosis. The strain 19 used in vaccine elaboration can be identified through a deletion in the eri region associated with its susceptibility to erythritol. We optimized a PCR assay for specific characterization of this strain. The method described here is a rapid procedure that enables identification of B. abortus, and simultaneous differentiation of the strain 19 from other B. abortus biovar 1 strains. We applied the assay to detect the strain 19 in vaccines against B. abortus produced in Argentina. The results show this method could be used to follow vaccine seed cultures of this strain. The methodology could also contribute to reduce the risk of a laboratory-acquired infection and could be of great help as a routine test for confirmation of B. abortus in non related vaccines.

Tipificación molecular de Brucella abortus cepa 19 y su aplicación al control de biológicos. / [Molecular characterization of Brucella abortus strain 19 and its application for controlling biologics]

Brucella abortus is the etiological agent of bovine brucellosis. The strain 19 used in vaccine elaboration can be identified through a deletion in the eri region associated with its susceptibility to erythritol. We optimized a PCR assay for specific characterization of this strain. The method described here is a rapid procedure that enables identification of B. abortus, and simultaneous differentiation of the strain 19 from other B. abortus biovar 1 strains. We applied the assay to detect the strain 19 in vaccines against B. abortus produced in Argentina. Thq results show this method could be used to follow vaccine seed cultures of this strain. The methodology could also contribute to reduce the risk of a laboratory-acquired infection and could be of great help as a routine test for confirmation of B. abortus in non related vaccines.