Division of Infectious Diseases, Chiba Children's Hospital, 579-1, Heta-cho, Midori-ku, Chiba-city, Chiba 266-0007, Japan.
Department of Infectious Diseases, Medical Mycology Research Center, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba-city, Chiba 260-8673, Japan.
J Med Microbiol. 2019 Oct;68(10):1534-1539. doi: 10.1099/jmm.0.001055.
. Certain nontypeable cannot be assigned a sequence type (ST) by Multilocus Sequence Typing (MLST) due to the lack of the gene, one of seven MLST loci in , which encodes a fucose-operon enzyme.. To confirm whether the loss of is also found in the encapsulated strains, we analysed clinical isolates of serotype e (Hie).. We conducted MLST, PFGE, and antimicrobial susceptibility tests of 45 Hie strains; the majority (=43) were derived from respiratory samples of pediatric patients at Chiba Children's Hospital between 2000 and 2016. The two remaining strains were obtained from the blood of elderly patients with invasive diseases (IHiDs) between 2015 and 2016 at general hospitals. For the -negative strains, PCR analysis for fucose operon was also performed.. Four STs (ST18, 122, 621 and 1758) were assigned to 13 strains, and remaining 32 (including one associated with IHiD) were -negative, completely missing the fucose operon. The allelic profiles of six other loci were identical among 31 strains and to that of ST18, 122 and 621, and these strains were genetically closely related. Forty of 45 isolates were ampicillin-sensitive.. The loss of was frequently observed in clinical isolates of Hie from children. Moreover, -negative Hie may be the cause of IHiD in adult patients. The majority of Hie, including -negative strains, were shown to be clonally related and were ampicillin sensitive. This represents the first report examining losses in encapsulated .
某些不可分型 不能通过多位点序列分型 (MLST) 分配序列型 (ST)，因为其缺乏 基因，该基因是 7 个 MLST 基因座之一，编码一种岩藻糖操纵子酶。为了确认缺失 是否也存在于有荚膜的菌株中，我们分析了 血清型 e (Hie) 的临床分离株。我们对 45 株 Hie 菌株进行了 MLST、PFGE 和抗菌药物敏感性试验；其中大多数（=43）是 2000 年至 2016 年期间从千叶儿童医院儿科患者的呼吸道样本中分离出来的。其余两株是从 2015 年至 2016 年期间在综合医院因侵袭性 疾病（IHiD）的老年患者血液中分离出来的。对于 -阴性菌株，还进行了岩藻糖操纵子的 PCR 分析。13 株菌株被分配了 4 个 ST（ST18、122、621 和 1758），其余 32 株（包括一株与 IHiD 相关）为 -阴性，完全缺失岩藻糖操纵子。31 株菌株的其余 6 个基因座的等位基因谱与 ST18、122 和 621 相同，这些菌株在遗传上密切相关。45 株分离株中有 40 株对氨苄西林敏感。在儿童来源的 Hie 临床分离株中经常观察到 的缺失。此外，-阴性 Hie 可能是成人患者 IHiD 的原因。大多数 Hie，包括 -阴性菌株，被证明是克隆相关的，并且对氨苄西林敏感。这是首次报道检查有荚膜的 中 的缺失。
