Durand Benjamin A R N, Yahiaoui Martinez Alex, Baud Damien, François Patrice, Lavigne Jean-Philippe, Dunyach-Remy Catherine
Bacterial Virulence and Chronic Infections, INSERM U1047, University of Montpellier, Department of Microbiology and Hospital Hygiene, University Hospital Nîmes, 30908 Nîmes, France.
Department of Microbiology and Hospital Hygiene, University Hospital Nîmes, University of Montpellier, 30029 Nîmes, France.
Genomics. 2022 May;114(3):110365. doi: 10.1016/j.ygeno.2022.110365. Epub 2022 Apr 9.
Helcococcus kunzii is a commensal Gram-positive bacterial species recovered from the human skin microbiota and considered as an opportunistic pathogen. Although little is known about its clinical significance, its increased abundance has been reported in infected wounds, particularly in foot ulcers in persons with diabetes. This species is usually detected in mixed cultures from human specimens and frequently isolated with Staphylococcus aureus. Modulation of staphylococci virulence by H. kunzii has been shown in an infection model of Caenorhabditis elegans. The aim of this study was to compare the genomes of two H. kunzii strains isolated from foot ulcers -isolate H13 and H10 showing high or low impact on S. aureus virulence, respectively- and the H. kunzii ATCC51366 strain. Whole genome analyses revealed some differences between the two strains: length (2.06 Mb (H13) and 2.05 Mb (H10) bp), GC content (29.3% (H13) and 29.5% (H10)) and gene content (1,884 (H13) and 1,786 (H10) predicted genes). The core-proteome phylogenies within the genus characterised H. kunzii H13 and H10 as genetically similar to their ancestor. The main differences between the strains were mainly in sugar-associated transporters and various hypothetical proteins. Five targets were identified as potentially involved in S. aureus virulence modulation in both genomes: the two-component iron export system and three autoinducer-like proteins. Moreover, H13 strain harbours a prophage inserted in 1,261,110-1,295,549 (attL-attR), which is absent in H10 strain. The prophage PhiCD38_2 was previously reported for its ability to modulate secretion profile, reinforcing the autoinducer-like hypothesis. In the future, transcriptomics or metaproteomics approaches could be performed to better characterize the H13 strain and possibly identify the underlying mechanism for S. aureus virulence modulation.
昆氏赫尔考克氏菌是一种从人体皮肤微生物群中分离出的革兰氏阳性共生细菌，被认为是一种机会致病菌。尽管对其临床意义了解甚少，但据报道，在感染伤口，尤其是糖尿病患者的足部溃疡中，其丰度有所增加。该菌种通常在人类标本的混合培养物中检测到，并经常与金黄色葡萄球菌一起分离出来。在秀丽隐杆线虫感染模型中，已显示昆氏赫尔考克氏菌对葡萄球菌毒力有调节作用。本研究的目的是比较从足部溃疡中分离出的两株昆氏赫尔考克氏菌——分别对金黄色葡萄球菌毒力有高影响和低影响的分离株H13和H10——与昆氏赫尔考克氏菌ATCC51366菌株的基因组。全基因组分析揭示了这两株菌之间的一些差异：长度（2.06 Mb（H13）和2.05 Mb（H10）碱基对）、GC含量（29.3%（H13）和29.5%（H10））和基因含量（1884个（H13）和1786个（H10）预测基因）。该属内的核心蛋白质组系统发育分析表明，昆氏赫尔考克氏菌H13和H10在基因上与其祖先相似。菌株之间的主要差异主要在于糖相关转运蛋白和各种假定蛋白质。在两个基因组中均鉴定出五个可能参与金黄色葡萄球菌毒力调节的靶点：双组分铁输出系统和三种自诱导样蛋白。此外，H13菌株含有一个插入在1261110 - 1295549（attL - attR）位置的原噬菌体，而H10菌株中不存在该原噬菌体。原噬菌体PhiCD38_2先前因其调节分泌谱的能力而被报道，这强化了自诱导样假说。未来，可以采用转录组学或元蛋白质组学方法来更好地表征H13菌株，并可能确定金黄色葡萄球菌毒力调节的潜在机制。
