Detection of fiber-digesting bacteria in the forestomach contents of llamas (Lama glama) by PCR

AbstractThe high fibrolytic activity and large biomass of strictly-anaerobic bacteria that inhabit the rumen makes them primarily responsible for the degradation of the forage consumed by ruminants. Llamas feed mainly on low quality fibrous roughages that are digested by an active and diverse microflora. The products of this fermentation are volatile fatty acids and microbial biomass, which will be used by the animals. The aim of this study was to detect the three major fiber-digesting anaerobic bacteria in the forestomach contents of llamas by PCR. In this study, we detected Ruminococcus albus, Ruminococcus flavefaciens and Fibrobacter succinogenes in the forestomach contents of eight native llamas from Argentina

Brucella

La brucelosis también llamada fiebre de Malta, fiebre ondulante o del Mediterráneo es una enfermedad zoonótica, conocida desde fines del siglo XIX, que afecta a especies animales de sangre caliente. Es de difusión mundial y aunque ha sido erradicada en algunos países industrializados continúa siendo un problema difícil de resolver en países del área del Mediterráneo, del oeste de Asia, de África y de América Latina. En nuestra región se la conoce desde principios del siglo XX, se cree que fue introducida con los animales ingresados por los españoles durante la conquista, aunque es difícil precisar dónde apareció por primera vez. Algunos autores afirman que en 1898 fue diagnosticada en Venezuela, también ha sido asociada a una epidemia descrita como fiebre de larga duración, ocurrida en Perú entre 1906 y 1907. Su persistencia se puede explicar por las particularidades geográficas de los países, la práctica de criar distintas especies de animales compartiendo pasturas y abrevaderos y la permanente interacción del medio rural con el urbano para adquirir insumos y comercializar productos. Los animales domésticos, en algunos lugares, son faenados sin control sanitario y sus múltiples derivados son manufacturados de manera artesanal, se expenden en la vecindad y en las rutas de acceso a las ciudades.Fil: Lucero, Nidia E.. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbrán"; ArgentinaFil: Almiron, Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Cravero, Silvio L.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias; ArgentinaFil: Trangoni, Marcos D.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias; Argentin

Comparison of four polymerase chain reaction assays for the detection of Brucella spp. in clinical samples from dogs

Aim: This study aimed to compare the sensitivity (S), specificity (Sp), and positive likelihood ratios (LR+) of four polymerase chain reaction (PCR) assays for the detection of Brucella spp. in dog's clinical samples. Materials and Methods: A total of 595 samples of whole blood, urine, and genital fluids were evaluated between October 2014 and November 2016. To compare PCR assays, the gold standard was defined using a combination of different serological and microbiological test. Bacterial isolation from urine and blood cultures was carried out. Serological methods such as rapid slide agglutination test, indirect enzyme-linked immunosorbent assay, agar gel immunodiffusion test, and buffered plate antigen test were performed. Four genes were evaluated: (i) The gene coding for the BCSP31 protein, (ii) the ribosomal gene coding for the 16S-23S intergenic spacer region, (iii) the gene coding for porins omp2a/omp2b, and (iv) the gene coding for the insertion sequence IS711. Results: The results obtained were as follows: (1) For the primers that amplify the gene coding for the BCSP31 protein: S: 45.64% (confidence interval [CI] 39.81-51.46), Sp: 95.62% (CI 93.13-98.12), and LR+: 10.43 (CI 6.04-18); (2) for the primers that amplify the ribosomal gene of the 16S-23S rDNA intergenic spacer region: S: 69.80% (CI 64.42-75.18), Sp: 95.62 % (CI 93.13-98.12), and LR+: 11.52 (CI 7.31-18.13); (3) for the primers that amplify the omp2a and omp2b genes: S: 39.26% (CI 33.55-44.97), Sp: 97.31% (CI 95.30-99.32), and LR+ 14.58 (CI 7.25-29.29); and (4) for the primers that amplify the insertion sequence IS711: S: 22.82% (CI 17.89 - 27.75), Sp: 99.66% (CI 98.84-100), and LR+ 67.77 (CI 9.47-484.89). Conclusion: We concluded that the gene coding for the 16S-23S rDNA intergenic spacer region was the one that best detected Brucella spp. in canine clinical samples

LAMP technology: Rapid identification of Brucella and Mycobacterium avium subsp. paratuberculosis

In this study, we developed new sets of primers to detect Brucella spp. and M. avium subsp. paratuberculosis (MAP) through isothermal amplification. We selected a previously well-characterized target gene, bscp31, specific for Brucella spp. and IS900 for MAP. The limits of detection using the loop-mediated isothermal amplification (LAMP) protocols described herein were similar to those of conventional PCR targeting the same sequences. Hydroxynaphtol blue and SYBR GreenTM allowed direct naked-eye detection with identical sensitivity as agarose gel electrophoresis. We included the LAMP-based protocol in a rapid identification scheme of the respective pathogens, and all tested isolates were correctly identified within 2 to 3 h. In addition, both protocols were suitable for specifically identifying the respective pathogens; in the case of Brucella, it also allowed the identification of all the biovars tested. We conclude that LAMP is a suitable rapid molecular typing tool that could help to shorten the time required to identify insidious bacteria in low-complexity laboratories, mainly in developing countries