Detection of Large Numbers of Pneumococcal Virulence Genes in Streptococci of the Mitis Group
Detection of Large Numbers of Pneumococcal Virulence Genes in Streptococci of the Mitis Group
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DOI：
10.1128/jcm.01746-09
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发表时间：
2010-08-01
影响因子：
9.4
通讯作者：
Mitchell, Tim J.
中科院分区：
文献类型：
--
作者：
Johnston, Calum;Hinds, Jason;Mitchell, Tim J.
通过基于肺炎链球菌TIGR 4和R6基因组开放阅读框的微阵列比较基因组杂交研究，分析了来自缓症组的7株链球菌分离株中肺炎球菌基因同源物的存在。肺炎链球菌溶血素（ply）和神经氨酸酶A（nanA）基因序列的多样性在14个S.假单胞菌和29个轻症组分离物。微阵列实验中使用的螨群分离株包括一个模式株（NCTC 12261）、两个S.从儿童鼻咽部分离到1株缓症链球菌;从1例感染性心内膜炎中分离到1株S. mitis。mitis分离自牙脓肿，和一个S. oralis isolate和1株S.从儿童鼻咽分离的假单胞菌。基因芯片研究结果表明，5S.与肺炎球菌毒力基因同源性在67%~ 82%之间; oralis与83%的肺炎球菌毒力基因杂交;假单胞菌与92%已鉴定的肺炎球菌毒力基因杂交。比较肺炎球菌溶血素、米替林溶血素（mly）和新鉴定的假肺炎球菌溶血素（pply）基因序列发现，mly和pply基因彼此之间的关系比两者与ply之间的关系更密切。相比之下，来自缓症组的肺炎球菌和链球菌中的nanA基因序列紧密聚集在一起，与肺炎球菌nanA等位基因共享99.4%至99.7%的序列同一性。
Seven streptococcal isolates from the mitis group were analyzed for the presence of pneumococcal gene homologues by comparative genomic hybridization studies with microarrays based on open reading frames from the genomes of Streptococcus pneumoniae TIGR4 and R6. The diversity of pneumolysin (ply) and neuraminidase A (nanA) gene sequences was explored in more detail in a collection of 14 S. pseudopneumoniae and 29 mitis group isolates, respectively. The mitis group isolates used in the microarray experiments included a type strain (NCTC 12261), two S. mitis isolates from the nasopharynxes of children, one S. mitis isolate from a case of infective endocarditis, one S. mitis isolate from a dental abscess, and one S. oralis isolate and one S. pseudopneumoniae isolate from the nasopharynxes of children. The results of the microarray study showed that the 5 S. mitis isolates had homologues to between 67 and 82% of pneumococcal virulence genes, S. oralis hybridized to 83% of pneumococcal virulence genes, and S. pseudopneumoniae hybridized to 92% of identified pneumococcal virulence genes. Comparison of the pneumolysin, mitilysin (mly), and newly identified pseudopneumolysin (pply) gene sequences revealed that mly and pply genes are more closely related to each other than either is to ply. In contrast, the nanA gene sequences in the pneumococcus and streptococci from the mitis group are closely clustered together, sharing 99.4 to 99.7% sequence identity with pneumococcal nanA alleles.