DNA extraction of urinary bladder swabs collected from carbonized and decomposing corpses: Possible application in disaster victim identification.

A disaster is an unexpected event causing death or injury to many people. In such events, a large number of casualties may take place, exposing corpses to a harsh environment for days or months. DNA profiling is recognized as one of the primary methods for identifying mass disaster victims, especially when it involves decomposed or fragmented bodies. The objective of this study was to standardize the use of urinary bladder swabs as a source of DNA for the identification of decomposing and carbonized human bodies by Forensic Genetic techniques. Samples' DNA was extracted using both organic and Chelex® resin methods; quantified by qPCR and amplified with PowerPlex® Fusion System (Promega Corporation). The results of this study show that between the two methodologies used for DNA extraction, the organic method presented higher DNA yields in relation to the minimum acceptable for the amplification, while Chelex®, although not having a high yield, still allowed obtaining significant amounts of DNA for amplification. The use of bladder swabs has proven to be a viable source of DNA for human identification, since besides reproducible and reliable results, this type of sample allows a significant reduction in the time and cost required for analysis.

PCR-restriction fragment length polymorphism analysis as a tool for Mycobacterium species identification in lepromas for lepromin production.

OBJECTIVES: The aim of the present work was to standardise a PCR-Restriction Fragment Length Polymorphism analysis (PRA) as a tool to detect the mycobacteriologic composition of lepromas from leprosy patients used in the production of lepromin to improve the quality of the Mitsuda test. DESIGN: PCR-Restriction Fragment Length Polymorphism analysis using hsp65 and rpoB genes were applied to 11 reference strains of mycobacteria, including M. leprae, and the obtained PRA profiles were compared to mycobacteria in clinical specimens. RESULTS: Out of the biopsies studied, 522% had DNA fragment amplified for both genes (hsp65 and rpoB) for M. leprae. However, other Mycobacterium species were observed in samples of lepromatous leprosy patients. Here we discussed the importance of mycobacteria identification in the antigen of Mitsuda production to be used in the evaluation of leprosy. CONCLUSIONS: Our results suggest that the use of the molecular approach for sample selection can contribute to an improvement in the quality of produced lepromin.

[Basic standards for Colombian paternity testing laboratories, 2005]. / Estándares baisicos para los laboratorios de pruebas de paternidad en Colombia, 2005.

The Commission for Accreditation and Surveillance of Laboratories Practicing DNA Paternity Tests (created by the Colombian Law 721/2001) set up sub-commission to review the current basic Colombian standards required for paternity testing laboratories and make specific recommendations re the pertinent technical aspects in Colombia, taking ISO 17025 as current reference. This document contains such recommendations for Colombia.

Estándares básicos para los laboratorios de pruebas de paternidad en Colombia, 2005 / Basic standards for Colombian paternity testing laboratories, 2005

La "Comisión de Acreditación y Vigilancia de los Laboratorios que practican las pruebas de paternidad o maternidad con marcadores genéticos de ADN", creada por la Ley 721 de 2001, constituyó una Sub-comisión para revisar las normas colombianas sobre los Estándares Básicos Requeridos en los Laboratorios de Pruebas de Paternidad, para que específicamente recomendara los aspectos técnicos pertinentes en Colombia, tomando como referente permanente la Norma ISO 17025. En este documento se consignan estas recomendaciones para Colombia.

Genotypic analysis of Staphylococcus aureus from milk of dairy cows with mastitis in Argentina.

Staphylococcus aureus is the most prevalent pathogen causing mastitis of dairy ruminants. This study was developed to ascertain the genotypes and genealogical relationship among strains isolated from milk of bovines with mastitis in Argentina. Molecular epidemiological analysis of S. aureus was performed on 112 isolates from 21 districts. Clonality was assessed by SmaI pulsed-field gel electrophoresis (PFGE) typing, automated EcoRI ribotyping and restriction enzyme analysis of plasmid (REAP) DNA profiles. A total of 22 band patterns distributed in four clusters were found by SmaI PFGE analysis. The similarity of clusters 2, 3 and 4 with cluster 1 was 0.73, 0.69 and 0.33, respectively, and 101 of 112 isolates belonged in cluster 1. PFGE band patterns from 42 isolates within cluster I were indistinguishable from each other (type A). The second largest group of isolates with indistinguishable PFGE band patterns was subtype A11, which was composed of 19 isolates. Automated ribotyping assigned the 112 isolates into 13 ribotypes. Among these, the most prevalent ribotypes I and VI were composed of 49 and 35 isolates respectively. Although there was certain correspondence between PFGE genotypes and ribotypes, further discrimination was achieved by combining both methods. REAP DNA profile analysis was useful to provide even further discrimination between isolates with identical PFGE genotype and ribotype. The most prevalent S. aureus strains A/I and A11/VI were widely distributed in the country and were not restricted to individual nearby locations. Prevalence of these two strains varied consecutively within a period of 8 years. Whether the shift in type prevalence was due to selection of a phenotypic trait remains undisclosed.