摘要

Choreseobacterium indologenes是一种新兴的医院内病原体，可产生IND型染色体金属-β-内酰胺酶。研究了两种多药耐药嗜水气单胞菌菌株的表型和分子方面以及IND酶的三级结构分析。使用Vitek-2压块进行物种鉴定和药敏试验。使用PureLink TM Genomic DNA Mini Kit和PureLink Quick Plasmid Miniprep Kit提取染色体和质粒DNA，并使用ABI 3130遗传分析仪进行测序。分离出两个菌株并记录为P-23和P-113。在这两者中，P-113仅对环丙沙星和头孢吡肟敏感，而P-23对头孢他啶，环丙沙星和替加环素的敏感性降低。两种分离株的遗传分析均鉴定出blaIND样基因的存在，与IND-3和IND-8等位基因具有相似性。在P-133样品中鉴定的IND-3在T355G位置呈现单突变，其对应于位置119（Ser→Ala）的氨基酸的非同义取代。 IND的系统发育分析显示在亚洲和欧洲国家流行的谱系。这些结果强调需要采取有效的预防措施，以避免在医院环境中传播这类病原体。

Chryseobacterium indologenes is an emerging nosocomial pathogen that produces IND-type chromosomal metallo-beta-lactamase. The phenotype and molecular aspects of two multidrug resistant C. indologenes strains and the analysis of the tertiary structure of the IND enzyme were studied. Identification of species and susceptibility tests were performed using the Vitek-2 compact. Chromosomal and plasmid DNA were extracted using PureLink™ Genomic DNA Mini Kit and PureLink Quick Plasmid Miniprep Kit, and the sequencing was performed using ABI 3130 genetic analyzer. Two strains were isolated and are registered as P-23 and P-113. Of the two, P-113 was sensitive to ciprofloxacin and cefepime only, whereas the P-23 showed reduced sensitivity to ceftazidime, ciprofloxacin, and tigecycline. The genetic analysis of both isolates identified the presence of the blaIND-like gene, with similarity to IND-3 and IND-8 alleles. The IND-3 identified in the P-133 sample presented a single mutation at position T355G, which corresponds to a nonsynonymous substitution of the amino acid at position 119 (Ser→Ala). The phylogenetic analysis of INDs showed lineages that are circulating in Asian and European countries. These results emphasize the need for effective preventive actions to avoid the dissemination of this type of pathogen in the hospital environment.

https://www.ncbi.nlm.nih.gov/pubmed/30585755