Abstract Pathogenic microbial detection and control in laboratory animal facilities is essential to guarantee animal welfare, data validity and reproducibility. Helicobacter spp. are known to affect mice health, what may interfere with experimental outcomes. This study aimed to screen for Helicobacter spp. in mice from animal facilities in Rio de Janeiro, Brazil using a PCR-based method. Primers designed to specifically identify Helicobacter spp. were used to amplify feces or intestine DNA extracted of mice from four different animal facilities. The expected 375 base pairs (bp) amplicon was purified, sequenced and a similarity of 95% was observed when compared to deposited sequences of H. hepaticus and H. bilis. In our screening, Helicobacter spp. was detected in ~59% of fecal and ~70% of intestine samples. Our study is the first to screen for Helicobacter spp. in mouse facilities of a Rio de Janeiro University using a low cost, rapid molecular diagnostic test. Although Helicobacter spp. screening is not mandatory according to Brazilian animal welfare regulation it is recommended by institutional animal health monitoring programs guidelines worldwide, including ARRIVE, AAALAC and FELASA.

RESUMOTecnologias de modificação do genoma são ferramentas poderosas para a biologia molecular e áreas afins. Avanços na transgênese animal e em tecnologias de edição do genoma durante as últimas três décadas permitiram interrogar de modo sistemático a função de genes, o que pode ajudar a compreender como o genoma influencia a fisiologia celular. A engenharia genética através de recombinação homóloga (HR) tem sido o método padrão para modificar sequências genômicas. No entanto, métodos de edição do genoma por nucleases que foram desenvolvidos recentemente, como ZFN, TALEN e CRISPR/Cas, trouxeram novas perspectivas para pesquisa biomédica. Aqui, apresentamos uma breve perspectiva histórica de métodos de modificação do genoma com foco em modelos de camundongos transgênicos. Além disso, descrevemos como novas técnicas foram descobertas e aperfeiçoadas, apresentamos as mudanças de paradigma e discutimos suas limitações e aplicações para a investigação biomédica, bem como possíveis direções futuras.

ABSTRACTGenome modification technologies are powerful tools for molecular biology and related areas. Advances in animal transgenesis and genome editing technologies during the past three decades allowed systematic interrogation of gene function that can help model how the genome influences cellular physiology. Genetic engineering via homologous recombination (HR) has been the standard method to modify genomic sequences. Nevertheless, nuclease-guided genome editing methods that were developed recently, such as ZFN, TALEN and CRISPR/Cas, opened new perspectives for biomedical research. Here, we present a brief historical perspective of genome modification methods, focusing on transgenic mice models. Moreover, we describe how new techniques were discovered and improved, present the paradigm shifts and discuss their limitations and applications for biomedical research as well as possible future directions.