Silva Adrianne M A, Luz Ana C O, Xavier Keyla V M, Barros Maria P S, Alves Hirisleide B, Batista Marcus V A, Leal-Balbino Tereza C
Departamento de Microbiologia, Instituto Aggeu Magalhães, Fundação Oswaldo Cruz, Recife CEP 50740-465, Pernambuco, Brazil.
Laboratório de Bioprocessos, Centro de Tecnologias Estratégicas do Nordeste, Recife CEP 50740-545, Pernambuco, Brazil.
Pathogens. 2023 May 26;12(6):764. doi: 10.3390/pathogens12060764.
CRISPR/Cas is a molecular mechanism to prevent predatory viruses from invading bacteria via the insertion of small viral sequences (spacers) in its repetitive locus. The nature of spacer incorporation and the viral origins of spacers provide an overview of the genetic evolution of bacteria, their natural viral predators, and the mechanisms that prokaryotes may use to protect themselves, or to acquire mobile genetic elements such as plasmids. Here, we report on the CRISPR/Cas genetic structure, its spacer content, and strain epidemiology through MLST and CRISPR typing in , an opportunistic pathogen intimately related to hospital infections and antimicrobial resistance. Results show distinct genetic characteristics, such as polymorphisms specific to ancestor direct repeats, a well-defined degenerate repeat, and a conserved leader sequence, as well as showing most spacers as targeting bacteriophages, and several self-targeting spacers, directed at prophages. There was a particular relationship between CRISPR/Cas and CC113 in the study of Brazilian isolates, and CRISPR-related typing techniques are interesting for subtyping strains with the same MLST profile. We want to emphasize the significance of descriptive genetic research on CRISPR loci, and we argue that spacer or CRISPR typing are helpful for small-scale investigations, preferably in conjunction with other molecular typing techniques such as MLST.
CRISPR/Cas是一种分子机制，可通过在其重复位点插入小的病毒序列（间隔序列）来防止掠夺性病毒入侵细菌。间隔序列的整合性质及其病毒来源概述了细菌的遗传进化、其天然病毒捕食者以及原核生物可能用于自我保护或获取移动遗传元件（如质粒）的机制。在此，我们通过多位点序列分型（MLST）和CRISPR分型报告了一种与医院感染和抗菌药物耐药性密切相关的机会性病原体——[具体病原体未提及]的CRISPR/Cas基因结构、其间隔序列内容和菌株流行病学。结果显示出明显的遗传特征，如祖先直接重复序列特有的多态性、明确的简并重复序列和保守的前导序列，同时还显示大多数间隔序列靶向噬菌体，以及一些靶向原噬菌体的自我靶向间隔序列。在巴西分离株的研究中，CRISPR/Cas与CC113之间存在特定关系，并且CRISPR相关分型技术对于对具有相同MLST谱型的菌株进行亚型分型很有意义。我们想强调对CRISPR位点进行描述性遗传研究的重要性，并且我们认为间隔序列或CRISPR分型有助于小规模研究，最好与其他分子分型技术（如MLST）结合使用。
