Evaluation of three alternatives cost-effective culture media for Mycobacterium tuberculosis detection and drug susceptibility determination using the microscopic observation drug susceptibility (MODS) assay.

Tuberculosis phenotypic detection assays are commonly used in low-resource countries. Therefore, reliable detection methods are crucial for early diagnosis and treatment. The microscopic observation drug susceptibility (MODS) assay is a culture-based test to detect Mycobacterium tuberculosis and characterize drug resistance in 7-10 days directly from sputum. The use of MODS is limited by the availability of supplies necessary for preparing the enriched culture. In this study, we evaluated three dry culture media that are easier to produce and cheaper than the standard one used in MODS [1]: an unsterilized powder-based mixed (Boldú et al., 2007) [2], a sterile-lyophilized medium, and (Sengstake et al., 2017) [3] an irradiated powder-based mixed. Mycobacterial growth and drug susceptibility were evaluated for rifampin, isoniazid, and pyrazinamide (PZA). The alternative cultures were evaluated using 282 sputum samples with positive acid-fast smears. No significant differences were observed in the positivity test rates. The positivity time showed high correlations (Rho) of 0.925, 0.889, and 0.866 between each of the three alternative media and the standard. Susceptibility testing for MDR and PZA showed an excellent concordance of 1 compared to the reference test. These results demonstrate that dry culture media are appropriate and advantageous for use in MODS in low-resource settings.

Alternative cost-effective media to facilitate MODS culture for diagnostics of tuberculosis.

Most culture-based methods for tuberculosis diagnosis remain low-cost options for low- and mid-income countries. The MODS culture is a rapid and low-cost assay to diagnose tuberculosis and determine drug susceptibility. However, its implementation is limited due to the low accessibility to supplies required for the enriched medium. In this study, we evaluate two alternative culture media: A powder-based mixed (PM) and a lyophilized media (LM). Catalase, PANTA, and gamma irradiation were evaluated as additions to PM and LM. The culture performance of the alternative media was compared with the standard MODS medium (MM) using Mycobacterium tuberculosis isolates and positive acid-fast smear sputum samples. Overall, no significant difference was observed in the bacterial growth between PM and LM with MM. However, PANTA and gamma irradiation combined reduced bacterial growth significantly in all media variants. A median positivity day of 6 ± 5 days was observed for sputum samples, regardless of the culture medium. The preliminary results show that the two variants culture media have a similar performance to the standard MODS medium. The powder-based media with PANTA (PM_P) showed a time-to-positivity and sensitivity similar to the standard MODS medium. It is the simplest to prepare and does not require any sterilization process.

Reproducibilidad en el diagnóstico imagenológico de periodontitis apical a partir de CBCT / Reproducibility of apical periodontitis diagnosis using CBCT imaging

Objetivo: evaluar la reproducibilidad en el diagnóstico imagenológico de Periodontitis Apical en dientes del maxilar superior, a partir de 60 CBCT tomadas en una institución clínica de Bucaramanga, Colombia. Métodos: el estudio fue realizado por dos obser-vadores, previamente calibrados, de CBCT del maxilar superior que contenían dientes permanentes con ápice cerrado, correspondientes a adultos mayores de 18 años de edad. La presencia o ausencia de periodontitis apical se analizó utilizando el índice CBCT PAI. La información registrada fue relacionada con variables de interés. Resultados:la reproducibilidad entre los evaluadores fue sustancial o perfecta. La prevalencia de periodontitis apical encontrada fue del 21,6%; en los dientes con tratamiento de en-dodoncia fue del 12,4% y en los dientes sin tratamiento endodóntico fue de un 9,2%. Conclusiones: la tomografía CBCT proporciona al clínico información que permite una mayor claridad en la fase de diagnóstico. Los dientes con la mayor prevalencia de PA fueron el primer molar y el primer premolar superior izquierdo, respectivamente.

Objective: To evaluate the reproducibility in the imaging diagnosis of apical periodontitis (PA) in upper jaw teeth from 60 cone beam computerized axial tomography (CBCT) taken at a clinical institution in an intermediate city in Colombia.Methods: The study was conducted by two previously calibrated observers from CBCT of the upper jaw containing permanent teeth with closed apex corresponding to adults over 18 years of age. The presence or absence of apical periodontitis was analyzed using the CBCT PAI index. The recorded information was related to variables of interest. Results: Reproducibility among testers was substantial or perfect. The prevalence of PA found was 21.6%, in teeth with endodontic treatment 12.4% and in teeth without endodontic treatment 9.2%. Conclusions: CBCT tomography provides the clinician with information that allows for greater clarity in the diagnostic phase. The teeth with the highest prevalence of PA were the first molar and first upper left premolar respectively.

La historia clínica de María / The clinical history of María

Se describe bajo un enfoque social que enlaza lo científico con lo empírico y, refuerza conceptos a favor de una asistencia médica eficiente a pesar de múltiples limitaciones