Abstract：
Two isolates (MC-18T and MC-17D), representing the Gram-stain-positive, facultatively anaerobic, irregular rod-shaped, non-motile, and non-spore-forming actinobacteria, were isolated from clinical breast specimens in Guangzhou, China. The growth of the isolates is enhanced by supplementing 1% Tween-80 on Luria Bertani agar. Optimal growth of the isolates was observed at 37 °C, pH 7-8, and with 1% (w/v) NaCl on Columbia blood agar. Pairwise comparison of the 16S rRNA gene sequences revealed that isolates MC-18T and MC-17D shared the highest sequence similarities with Corynebacterium liangguodongii 2184T (96.9%), which were lower than the threshold value for species delineation (98.65%). Phylogenetic dendrograms based on the 16S rRNA gene, rpoB gene, and core genomes indicated that two isolates formed a distinct lineage within the genus Corynebacterium. The estimated dDDH, ANIb, ANIm, and AAI values between strain MC-18T and its closely related strains were below the threshold values generally considered for recognizing a new species. The genome DNA G + C contents of both the isolates MC-18T and MC-17D are 60.6%. The two isolates have virulence-related genes of the VF classes of adhesion and antiphagocytosis, and also contain the antimicrobial resistance genes ErmX, mtrA, rpoB2, and RbpA. The major fatty acids (> 10%) of isolates MC-18T and MC-17D were C16:0, C18:1 ω9c, C18:0 and summed feature 5 (anteiso-C18:0 and/or C18:2 ω6,9c). The main respiratory quinone of strain MC-18T was MK-8(H2), and the polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, three unidentified glycolipids, an unidentified aminolipid, and four unidentified phosphoglycolipids. The two isolates lack mycolic acids in the cell envelope. Based on the above findings, the two isolates are considered to represent a novel species of the genus Corynebacterium, for which the name Corynebacterium lipophilum sp. nov. is proposed, with isolate MC-18T (= NBRC 115144T = CCTCC AB 2020201T) as the type strain. An emended description of the Corynebacterium pilbarense is also provided.
摘要：
两个分离株（MC-18T和MC-17D），代表革兰氏染色阳性，兼性厌氧，不规则的杆状,不活动，和非孢子形成的放线菌，从广州的临床乳腺标本中分离出来，中国。通过在LuriaBertani琼脂上补充1%Tween-80来增强分离物的生长。在37°C下观察到分离物的最佳生长，pH7-8，并在哥伦比亚血琼脂上加入1％（w/v）NaCl。16SrRNA基因序列的成对比较显示，分离株MC-18T和MC-17D与梁古多吉棒状杆菌2184T具有最高的序列相似性（96.9％），低于物种划分的阈值(98.65%)。基于16SrRNA基因的系统发育树状图，rpoB基因,和核心基因组表明，两个分离株在棒杆菌属内形成了不同的谱系。估计的dDDH，ANIb,ANIm,菌株MC-18T与其密切相关的菌株之间的AAI值低于通常认为用于识别新物种的阈值。分离株MC-18T和MC-17D的基因组DNAGC含量均为60.6%。这两个分离株具有VF类粘附和抗吞噬作用的毒力相关基因，还含有抗微生物药物抗性基因ErmX，mtrA,rpoB2和RbpA。分离物MC-18T和MC-17D的主要脂肪酸(>10%)为C16:0,C18:1ω9c,C18:0和求和特征5(anteiso-C18:0和/或C18:2ω6,9c)。菌株MC-18T的主要呼吸醌是MK-8（H2），极性脂质由磷脂酰甘油组成，二磷脂酰甘油，磷脂酰肌醇,磷脂酰肌醇甘露糖苷,三种身份不明的糖脂，一种身份不明的氨基脂质,和四种身份不明的磷酸糖脂.这两个分离株在细胞包膜中缺乏霉菌酸。基于上述发现,这两个分离株被认为代表了棒状杆菌属的一个新物种，其名称为亲脂棒状杆菌sp。11月。被提议，以分离株MC-18T(=NBRC115144T=CCTCCAB2020201T)为类型菌株。还提供了毛棒状杆菌的修正描述。
