Bovine Tuberculosis Testing in Colombia: Comparative Histopathological, Microbiological, and Molecular Biology Findings

Introduction: Bovine tuberculosis (bTB) is a zoonotic infectious disease present in Colombia, caused by Mycobacterium bovis, and causes tuberculosis in water buffalo (Bubalus bubalis). Diagnosis of bovine tuberculosis through the intradermal test is difficult; evaluating and understanding the behavior of other diagnostic tests is necessary. Objective: To describe the behavior and results of different diagnostic methods for bovine tuberculosis in water buffalo positive for the Purifed Proteic Derivate (DPP) intradermal test. Methodology: In water buffaloes positive for comparative cervical tuberculin test, different diagnostic methods were applied, described, and compared: Ziehl-Neelsen staining, microbiological culture, histopathological analysis, and PCR-HRM. Results: Histopathological tests showed that 26 water buffalo positive for DPP (52%) had histological lesions compatible with bovine tuberculosis. 37% of the evaluated samples from tuberculin-positive Buffalo's lungs and secondary lymph nodes showed acid-alcohol-resistant bacillus with Ziehl-Neelsen staining. Four samples of Mycobacterium bovis from tuberculin-positive buffalo were isolated and identified, with two of these isolates confirmed from tissues with PCR-HRM, and three buffalo with microbiological isolates presented granulomatous lesions through histological analysis. Seventeen tuberculin-positive buffalo (34%) tested positive for real-time PCR HRM, and nine of these buffalo did not have histological lesions compatible with bTB and were confirmed with the molecular test. Conclusion: Our results provide positive evidence of histological findings, microbiological isolation, and molecular diagnosis of tuberculin-positive water buffalo in the lowlands of Colombia. None of the complementary tests performed showed 100% concordance with the comparative cervical tuberculin test results for bTB

Hepcidina y parámetros del hierro en donantes de sangre

Introducción: la hepcidina es la principal hormona peptídica reguladora de la absorción y distribución tisular del hierro. Estudios recientes han planteado la posibilidad de utilizarla como un biomarcador para evaluar el metabolismo del hierro y sus posibles alteraciones. Aunque, ante la escasa información sobre las propiedades diagnósticas de la hepcidina sérica, no han sido bien caracterizadas y no se cuenta con estudios suficientesen individuos sanos, e incluso en Colombia hasta el momento no se ha realizado ningún estudio referente al tema. Objetivo: estimar las concentraciones de la hepcidina sérica, su rango de normalidad y su correlación con parámetros bioquímicos asociados al metabolismo del hierro en una población de donantes. Materiales y métodos: estudio descriptivo transversalque incluyó 85 donantes, a quienes se les realizó hemograma automatizado, se evaluó ferritina, transferrina y hierro total, mediante los métodos de electroquimioluminiscencia, inmunoturbidimetría y colorimetría. La determinación de hepcidina en suero se realizó por medio de una ELISAcompetitiva. Se utilizaron pruebas estadísticas, con un nivel de significancia de p< 0,05. Resultados: se observaron diferencias significativas en la concentración de hepcidina entre hombres y mujeres. La edad no fue un factor determinante de las concentraciones de hepcidina en los hombres Mediana (Me)=5,73 nM. Solo ferritina se correlacionó fuertemente con lahepcidina. El rango de normalidad de hepcidina encontrado en hombres estuvo entre 1,71 y 13,3 nM y entre 1,67 a 11,3 nM en mujeres. Conclusión: el nivel de hepcidina sérica es mayor en hombres y demuestra la fuerte asociación in vivo con los niveles de hepcidina sérica con el hierro de reserva y circulante

Evaluation of virulence factors in clinical isolates of pathogenic E. coli in avian samples in Caloto, Colombia

Avian pathogenic E. coli (APEC), produces an extraintestinal infection in chickens, turkeys, and other types of birds, called colibacillosis, which is considered one of the main causes of economic losses due to morbidity, mortality, and discard of poultry carcasses. The objective of the present study was to characterize the genetic profile of the virulence factors of different isolates of avian E. coli in Caloto, Cauca, Colombia. Materials and methods: E. coli was isolated and identified by biochemical tests, from 47 clinical isolates. Subsequently, the DNA was extracted using Chelex. Three multiplex PCRs were designed to amplify 13 virulence factors (iroN, hlyF, iss, iutA, frz, vat, sitA, KpsM, sitD, fimH, pstB, sopB, and uvrY), using primers previously reported for each. At the end, the amplification products were verified on agarose gels. Each isolate was classified according to the number of virulence factors: group A (between 10 and 13), group B (between 5 and 9), and group C (4 or less). Discussion and Conclusions: we were able to identify the presence of a group of virulence factors in clinical isolates of APEC, which allows us to demonstrate that both the frequency and the profile of virulence factors in the isolated strains showed a different profile than the reported by other authors. The virulence genes pstB and fimH were detected in all our samples, and the iss gene was the one with the lowest frequency. Finally, according to the number of virulence factors, the group A was the most frequent