Laboratory of Bacteriology, Department of Microbiology, University Hospital Henri Mondor, Créteil, France.
Department of Bacteriology, Archet 2 Hospital, Nice Academic Hospital, Nice, France.
J Hosp Infect. 2017 Jun;96(2):183-188. doi: 10.1016/j.jhin.2017.02.003. Epub 2017 Feb 9.
Stenotrophomonas maltophilia is an opportunistic multi-drug-resistant bacterium responsible for healthcare-associated infections. Strategies for in-hospital infection control and management of carriers and environmental reservoirs remain controversial.
To determine the population structure of S. maltophilia strains in hospitalized infected patients and to identify putative highly pathogenic subpopulations that require upgraded infection control measures.
Eighty-three diverse human strains of various clinical origins from 18 geographically distant hospitals were characterized phenotypically and genotypically using a multi-locus sequence typing (MLST) approach.
Neither a predominant nor emerging sequence type (ST) was identified. Among the 80 typeable strains, only 29% corresponded to described STs, especially ST5 (N=6) and ST4/26/31 (N=2). The ST distribution and the phylogenic tree based on the concatenated MLST genes did not account for geographical, clinical origin or antimicrobial susceptibility clustering. A phylogenic tree that included 173 ST profiles from the MLST database and the 80 typeable strains confirmed the high genetic diversity of S. maltophilia, the previously reported genogroup organization and the predominance of genogroup 6, as it represented 41% (33/80) of the strains. Unexpectedly, genogroup 2 was the second most prevalent genogroup and included 16% (13/80) of the strains. These genogroups represented 57% (20/35) of the strains in respiratory patients and 75% (9/12) of the strains in patients with cystic fibrosis.
Beyond MLST, the over-representation of some genogroups among strains responsible for healthcare-associated infections was confirmed. Genogrouping affiliation is recommended to implement infection control measures selectively for the most pathogenic strains isolated from patient or environmental reservoirs.
嗜麦芽寡养单胞菌是一种机会性、多药耐药细菌，可导致医院获得性感染。医院内感染控制和携带者及环境储源管理策略仍存在争议。
确定住院感染患者中嗜麦芽寡养单胞菌菌株的种群结构，并确定需要升级感染控制措施的潜在高致病性亚群。
采用多位点序列分型（MLST）方法对来自 18 家地理位置不同的医院的 83 株不同临床来源的多样化人源菌株进行表型和基因型特征分析。
未确定主要或新兴的序列型（ST）。在 80 株可分型菌株中，只有 29%符合已描述的 ST，特别是 ST5（N=6）和 ST4/26/31（N=2）。ST 分布和基于串联 MLST 基因的系统发育树不能解释地理、临床来源或抗菌药物敏感性聚类。包括来自 MLST 数据库的 173 个 ST 谱和 80 个可分型菌株的系统发育树证实了嗜麦芽寡养单胞菌的高遗传多样性、先前报道的基因群组织和以基因群 6 的优势，因为其代表了 80 株菌株中的 41%（33/80）。出乎意料的是，基因群 2 是第二大常见的基因群，包括 80 株菌株中的 16%（13/80）。这些基因群在呼吸道患者中的菌株占 57%（20/35），在囊性纤维化患者中的菌株占 75%（9/12）。
除 MLST 外，还证实了一些基因群在与医院获得性感染相关的菌株中过度表达。建议进行基因群分析，以便针对从患者或环境储源中分离出的最具致病性的菌株选择性地实施感染控制措施。
