摘要

       在美国，社区获得性耐多药（MDR）肠杆菌科（Ent）感染继续增加。在先前的研究中，我们确定了伊利诺伊州芝加哥的邻近地区，那里的儿童患MDR-Ent感染的几率是该地区的5-6倍。为了防止MDR-Ent的社区传播，我们需要确定MDR-Ent水库。对芝加哥4条水路MDR-Ent及相关耐药基因（ARGs）进行了初步研究。三条水道（A1-A3）被贴上了“偶然接触娱乐”（如皮划艇）的安全标签，A4则是一条非娱乐水道，可输送未经消毒的水。收集和处理地表水样品，进行标准细菌培养和鸟枪基因组测序。一般来说，A3和A4（非水力连通的邻近水道）在Ent内的细菌类群、ARG剖面和相应的分支和属的丰度上惊人地相似。此外，从全微生物群落中回收的总ARG丰度在A3和A4之间呈强相关（R2=0.97）。E、 相对于A2（84 MPN）和A1（32 MPN），A4（783最可能数[MPN]）和A3（200 MPN]）的大肠杆菌数（每100毫升水）最高。我们在耳鼻喉科发现了MCR-1（colistin）、Qnr和OqxA/B（喹诺酮类）、CTX-M、OXA和ACT/MIR（β-内酰胺类）以及AAC（氨基糖苷类）等ARGs。我们发现，在没有水力连接的附近水道之间，微生物群落组成存在显著的相关性，这表明了交叉播种和ARGs迁移的潜力。耳鼻喉科和精氨酸概况支持假设的关注，休闲水道是一个潜在的来源，社区获得的多药耳鼻喉科。

Community-acquired multi-drug resistant (MDR) Enterobacteriaceae (Ent) infections continue to increase in the U.S. In prior studies we identified neighboring regions in Chicago, Illinois where children have a 5-6 times greater odds of MDR-Ent infections. To prevent community spread of MDR-Ent, we need to identify the MDR-Ent reservoirs. A pilot study of 4 Chicago waterways for MDR-Ent and associated antibiotic resistance genes (ARGs) was conducted. Three waterways (A1-A3) are labelled safe for "incidental contact recreation" (e.g. kayaking) and A4 is a non-recreational waterway that carries non-disinfected water. Surface water samples were collected and processed for standard bacterial culture and shotgun metagenomic sequencing. Generally, A3 and A4 (neighboring waterways which are not hydraulically connected) were strikingly similar in bacterial taxa, ARG profiles, and abundances of corresponding clades and genera within Ent. Additionally, total ARG abundances recovered from the full microbial community were strongly correlated between A3 and A4 (R²=0.97). E. coli numbers (per 100mL water) were highest in A4 (783 Most Probable Number [MPN]) and A3 (200 MPN) relative to A2 (84 MPN) and A1 (32 MPN). We found concerning ARGs in Ent such as MCR-1 (colistin), Qnr and OqxA/B (quinolones), CTX-M, OXA and ACT/MIR (β-lactams), and AAC (aminoglycosides). We found significant correlations in microbial community composition between nearby waterways that are not hydraulically connected, suggesting cross-seeding and the potential for mobility of ARGs. Ent and ARG profiles support the hypothesized concerns that recreational waterways are a potential source of community-acquired MDR-Ent.

       https://aac.asm.org/content/early/2020/01/28/AAC.02310-19.long