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The adulteration of meat products can affect the confidence of consumers and the market, leading to negative impacts on the economy. Accordingly, product authenticity has become an important issue in modern society. Therefore, our study aimed to optimize the extraction of DNA from meat and use multiplex polymerase chain reaction (mPCR) to determine the incidence of fraud by substitution of bovine meat cuts with water buffalo meat in the states of Pará and Amapá, Northern Brazil. The mPCR protocol used primers that amplify sequences of 346 base pairs of bovine DNA and 220 base pairs of buffalo DNA. To assess the sensitivity of the technique, a standardized PCR assay was performed using the template DNA extracted and diluted from 10−0 to 10−10 in PCR-grade water. Next, 161 samples of meat cuts marketed as bovine (rump) origin were collected in the states of Pará and Amapá, Northern Brazil. The mPCR assays demonstrated good specificity of the primers used. The sensitivity test amplified bovine and buffalo DNA fragments down to the 10−2 dilution. The results demonstrated fraud by substitution of beef by water buffalo meat in 21.7% of samples, demonstrating that this act does occur intentionally for economic gains. [ABSTRACT FROM AUTHOR]

A challenge of metagenomic studies is in the extraction and purification of DNA from environmental samples. The soils of the Cerrado region of Brazil present several technical difficulties to DNA extraction: high clay content (>55% w/w), low pH (4.7) and high iron levels (146 ppm). Here we describe for the first time the efficient recovery and purification of microbial DNA associated with these unusual soil characteristics and the construction and validation of two metagenomic libraries: a 150,000 clones library with insert size of approximately 8 kb and a 65,000 clones library with insert size of approximately 35 kb. The construction of these metagenomic libraries will allow the biotechnological exploitation of the microbial community present in the soil from this endangered biome. [ABSTRACT FROM AUTHOR]

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The absence of a standardized method for detecting oocysts in water samples makes it difficult to characterize them, including in water for reuse. This study aimed to detect Toxoplasma gondii oocysts using two extraction methods. Using method 1693/2014 USEPA, 30 L of water for reuse from two wastewater treatment plants (WWTPs) in the city of São Paulo, Brazil, was concentrated, totaling 20 samples. The supernatant generated from the immunomagnetic separation (IMS) step was collected for detection of T. gondii oocysts. For DNA extraction, two techniques were used: the commercial kit DNeasy PowerSoil Kit® optimized with the enzyme Zymolyase® and with freeze-thaw steps. DNA quantification was performed with the target sequence of gene B1. From 16 samples submitted to enzymatic extraction, four were positive. In freeze-thaw extraction, no DNA was detected. DNA extraction was the essential step for oocyst detection given the resistant nature of their wall., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Tuberculosis (TB) is one of the infectious diseases with high mortality in the world. DNA amplification techniques have been used to overcome barriers to the diagnosis of this disease. However, the success of these methodologies is highly dependent on the DNA obtained from the sample. This study was carried out to verify whether the DNA extracted by sonication (in house method) could yield suitable DNA for amplification by real-time PCR (qPCR). Sixty sputum samples were submitted to DNA extraction using sonication compared to a commercial method (Detect-TB kit, Labtest/MG-Brazil). All DNA samples were amplified by qPCR for IS6110 region (IS6110-qPCR/SYBR Green assay). Out of 60 samples, 40 were positive for TB; of these, all had positive results when extracted by sonication (100%) and 80% when extracted by the commercial method. The limit of detection (LOD) of Mycobacterium tuberculosis (H37Rv strain) by qPCR was 14 CFU/mL when the DNA was extracted by sonication, compared to countless colonies when extracted by commercial kit. In conclusion, the sonication protocol (without purification step) proved to be a simple, fast, and suitable method for obtaining DNA for use in qPCR from sputum samples., (Copyright © 2020 Sociedade Brasileira de Infectologia. Published by Elsevier España, S.L.U. All rights reserved.)

Despite the importance in conservation and breeding purposes, molecular studies using Cerrado plant species are still rare, mainly because of their high amounts of secondary compounds, impeding DNA extraction to downstream applications, such as PCR amplification. To date, the DNA extraction methods described are sometimes inadequate for these species, expensive, time-intensive and/or use very toxic reagents. Here, we present a simple and effective method, based on SDS and Triton X-100, to obtain high DNA quality and quantity from Cerrado plant species for molecular biological techniques. The DNA obtained by our protocol was free of contaminants and excellent for enzymatic restriction and PCR amplification. The concentration of extracted DNA across all tested species ranged from 156 to 1166 ng µL -1 (1.56-11.66 µg g -1 of dry tissue), with an A 260 /A 280 ratio from 1.78 to 1.92. The new DNA extraction protocol described here provides high DNA quality and quantity from Cerrado plant species in a fast, simple and less toxic way. Thus, the use of our method will allow ecologists, geneticists and breeders to rapidly obtain high-quality and -quantity DNA from Cerrado plant species for any molecular biology study.

Human papillomavirus (HPV) is found in adults and adolescents and is associated with genital warts and cervical cancer. However, it has been detected in girls younger than 10 years old. Currently, there are no prevention methods for this age group, since it is not considered a risk group. The aim of this study was to evaluate the presence of infection and HPV subtype in girls under 9 years old attended at a referral service in the State of Espírito Santo, Brazil. Forty-three girls younger than 9 years old had gynecological brush samples collected from vulval and perineal/anal regions. Viral detection and subtyping were done using polymerase chain reaction, restriction fragment length polymorphism and DNA sequencing. Statistics was performed using Action Stat 3.1. The mean age of girls was 6.1 years. Sexual activity and abuse were not reported by 95.3%. Family stories showed viral infection in 9.3% of mothers, 4.7% of fathers and 9.3% of caretakers. None of these were related with the children infection. In the only case of mother's gestational HPV infection, the daughter tested negative. Genital warts and infection were observed in 7% and 13.9% of the patients, respectively. Viral subtypes detected were 6, 11, 38, and 42. These results demonstrate the presence of HPV infection in girls under 9 years of age. Prevalence studies are needed in order to evaluate a possible alteration in age of vaccination policy., (© 2017 Wiley Periodicals, Inc.)