Commensal non-pathogenic Neisseria spp. live within the human host alongside the pathogenic Neisseria meningitidis and Neisseria gonorrhoeae and due to natural competence, horizontal gene transfer within the genus is possible and has been observed. Four distinct Neisseria spp. isolates taken from the throats of two human volunteers have been assessed here using a combination of microbiological and bioinformatics techniques. Three of the isolates have been identified as Neisseria subflava biovar perflava and one as Neisseria cinerea . Specific gene clusters have been identified within these commensal isolate genome sequences that are believed to encode a Type VI Secretion System, a newly identified CRISPR system, a Type IV Secretion System unlike that in other Neisseria spp., a hemin transporter, and a haem acquisition and utilization system. This investigation is the first to investigate these systems in either the non-pathogenic or pathogenic Neisseria spp. In addition, the N. subflava biovar perflava possess previously unreported capsule loci and sequences have been identified in all four isolates that are similar to genes seen within the pathogens that are associated with virulence. These data from the four commensal isolates provide further evidence for a Neisseria spp. gene pool and highlight the presence of systems within the commensals with functions still to be explored.

中文翻译：

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四种共生奈瑟菌属中的毒力基因和以前未探索过的基因簇。从人类喉咙中分离出来的奈瑟氏菌基因库。

共生非致病性奈瑟菌属。与致病性脑膜炎奈瑟菌和淋病奈瑟菌一起生活在人类宿主中，由于自然能力，该属内的水平基因转移是可能的，并已被观察到。四种不同的奈瑟菌属。在这里，结合微生物学和生物信息学技术对从两名人类志愿者喉咙中提取的分离株进行了评估。该分离的三个已被确定为奈瑟subflava生化型perflava和一个为奈瑟菌 . 在这些共生分离株基因组序列中已鉴定出特定的基因簇，据信这些基因簇编码 VI​​ 型分泌系统、新鉴定的 CRISPR 系统、与其他奈瑟菌属不同的 IV 型分泌系统、血红素转运蛋白和血红素获取和利用系统。这项调查是首次在非致病性或致病性奈瑟菌属中研究这些系统。此外，N. subflava生物变种perflava 具有先前未报告的荚膜位点，并且在所有四个分离株中均已鉴定出与在病原体中看到的与毒力相关的基因相似的序列。来自四个共生分离株的这些数据为奈瑟菌属提供了进一步的证据。基因库并突出显示共生体中存在的功能仍有待探索的系统。