Rodríguez-Rubio Lorena, Haarmann Nadja, Schwidder Maike, Muniesa Maite, Schmidt Herbert
Department of Genetics, Microbiology and Statistics, University of Barcelona, Diagonal 643, 08028 Barcelona, Spain.
Department of Food Microbiology and Hygiene, Institute of Food Science and Biotechnology, University of Hohenheim, 70599 Stuttgart, Germany.
Pathogens. 2021 Mar 29;10(4):404. doi: 10.3390/pathogens10040404.
Shiga toxins (Stx) of Shiga toxin-producing (STEC) are generally encoded in the genome of lambdoid bacteriophages, which spend the most time of their life cycle integrated as prophages in specific sites of the bacterial chromosome. Upon spontaneous induction or induction by chemical or physical stimuli, the genes are co-transcribed together with the late phase genes of the prophages. After being assembled in the cytoplasm, and after host cell lysis, mature bacteriophage particles are released into the environment, together with Stx. As members of the group of lambdoid phages, Stx phages share many genetic features with the archetypical temperate phage Lambda, but are heterogeneous in their DNA sequences due to frequent recombination events. In addition to Stx phages, the genome of pathogenic STEC bacteria may contain numerous prophages, which are either cryptic or functional. These prophages may carry foreign genes, some of them related to virulence, besides those necessary for the phage life cycle. Since the production of one or more Stx is considered the major pathogenicity factor of STEC, we aim to highlight the new insights on the contribution of Stx phages and other STEC phages to pathogenicity.
产志贺毒素大肠杆菌（STEC）的志贺毒素（Stx）通常编码在λ样噬菌体的基因组中，这些噬菌体在其生命周期的大部分时间里作为前噬菌体整合在细菌染色体的特定位点。在自发诱导或化学或物理刺激诱导后，这些基因与前噬菌体的晚期基因一起被共转录。在细胞质中组装后，宿主细胞裂解后，成熟的噬菌体颗粒与Stx一起释放到环境中。作为λ样噬菌体群体的成员，Stx噬菌体与典型的温和噬菌体λ具有许多遗传特征，但由于频繁的重组事件，它们的DNA序列存在异质性。除了Stx噬菌体，致病性STEC细菌的基因组可能包含许多前噬菌体，这些前噬菌体要么是隐蔽的，要么是功能性的。这些前噬菌体可能携带外源基因，其中一些与毒力有关，此外还有噬菌体生命周期所需的基因。由于产生一种或多种Stx被认为是STEC的主要致病因素，我们旨在突出关于Stx噬菌体和其他STEC噬菌体对致病性贡献的新见解。
