A prospective study was conducted on patients with mechanical ventilation from July 2018 to December 2019 in a tertiary hospital. Multi-genomics studies (16S rRNA amplicon, metagenomics, and whole-genome sequencing [WGS]) of endotracheal deep aspirate (ETA) were performed.
Fifty-two ICU patients were enrolled, including 24 with CRAB VAP (CRAB-I), 22 with CRAB colonization (CRAB-C), and six CRAB-negative patients (infection-free) (CRAB-N). Diversity of pulmonary microbiota was significantly lower in CRAB-I than in CRAB-C or CRAB-N (mean Shannon index, 1.79 vs. 2.73 vs. 4.81, P < 0.05). Abundances of 11 key genera differed between the groups. Acinetobacter was most abundant in CRAB-I (76.19%), moderately abundant in CRAB-C (59.14%), and least abundant in CRAB-N (11.25%), but its interactions with other genera increased in turn. Metagenomics and WGS analysis showed that virulence genes were more abundant in CRAB-I than in CRAB-C. Multi-locus sequence typing (MLST) of 46 CRAB isolates revealed that the main types were ST208 (30.43%) and ST938 (15.22%), with no difference between CRAB-I and CRAB-C.
Lower respiratory tract microbiota dysbiosis including elevated relative abundance of Acinetobacter and reduced bacterial interactions, and virulence enrichment may lead to CRAB VAP.
对2018年7月至2019年12月在三级医院接受机械通气的患者进行了一项前瞻性研究。多基因组学研究(16SrRNA扩增子,宏基因组学,和气管内深部抽吸物(ETA)的全基因组测序[WGS])。
纳入52名ICU患者,包括24个带有CRABVAP(CRAB-I)的设备,22与CRAB定殖(CRAB-C),和6名CRAB阴性患者(无感染)(CRAB-N)。CRAB-I的肺部微生物群多样性显着低于CRAB-C或CRAB-N(平均Shannon指数,1.79vs.2.73vs.4.81,P<0.05)。11个关键属的丰度在组间不同。CRAB-I中不动杆菌含量最高(76.19%),CRAB-C含量中等(59.14%),CRAB-N含量最低(11.25%),但它与其他属的相互作用又增加了。宏基因组学和WGS分析表明,CRAB-I中的毒力基因比CRAB-C中的毒力基因更丰富。46株CRAB分离株的多位点序列分型(MLST)显示主要类型为ST208(30.43%)和ST938(15.22%),CRAB-I和CRAB-C没有区别
下呼吸道微生物群菌群失调,包括不动杆菌的相对丰度升高和细菌相互作用减少,毒力富集可能导致CRABVAP。