Campus of Ceilândia, University of Brasília. Centro Metropolitano, Conjunto A, Ceilândia Sul, Brasília, DF, CEP: 72220-275, Brazil.
Central Laboratory for Public Health (LACEN-DF), SGAN 601, Asa Norte, Brasília, DF, CEP: 70830-010, Brazil.
BMC Microbiol. 2022 Jan 4;22(1):6. doi: 10.1186/s12866-021-02400-1.
Aquatic matrices impacted by sewage may shelter carbapenem-resistant (CR) Gram-negative bacilli (GNB) harboring resistance genes of public health concern. In this study, sewage treatment plants (STPs) servicing well-defined catchment areas were surveyed for the presence of CR-GNB bearing carbapenemase genes (bla or bla).
A total of 325 CR-GNB were recovered from raw (RS) and treated (TS) sewage samples as well as from water body spots upstream (UW) and downstream (DW) from STPs. Klebsiella-Enterobacter (KE) group amounted to 116 isolates (35.7%). CR-KE isolates were recovered from TS, DW (35.7%) and RS samples (44.2%) (p = 0.001); but not from UW samples. KE isolates represented 65.8% of all bla or bla positive strains. The frequency of bla strains was positively associated with the occurrence of district hospitals located near STPs, as well as with the number of hospitalizations and of sewer connections serviced by the STPs. bla strains were recovered from ST samples in 7 out of 14 STPs, including four tertiary-level STPs; and from 6 out of 13 DW spots whose RS samples also had bla strains.
Clinically relevant GNB bearing bla resist sewage treatments and spread into environmental aquatic matrices mainly from STPs impacted by hospital activities.
受污水影响的水生基质可能藏匿着携带公共卫生关注的耐药基因的耐碳青霉烯类（CR）革兰氏阴性杆菌（GNB）。在本研究中，对服务于明确集水区的污水处理厂（STP）进行了调查，以检测携带碳青霉烯酶基因（bla 或 bla）的 CR-GNB 的存在情况。
从 raw（RS）和 treated（TS）污水样本以及 STP 上游（UW）和下游（DW）水体样本中总共回收了 325 株 CR-GNB。肠杆菌科（KE）组有 116 株分离株（35.7%）。CR-KE 分离株从 TS、DW（35.7%）和 RS 样本（44.2%）中回收（p = 0.001）；但 UW 样本中未回收到。KE 分离株占所有 bla 或 bla 阳性菌株的 65.8%。bla 菌株的频率与位于 STP 附近的地区医院的发生以及 STP 服务的住院人数和污水连接数量呈正相关。在 14 个 STP 中有 7 个 STP 从 ST 样本中回收了 bla 菌株，包括 4 个三级 STP；从 13 个 DW 点中的 6 个点回收了 bla 菌株，这些 DW 点的 RS 样本也有 bla 菌株。
临床上相关的携带 bla 耐药基因的 GNB 能够抵抗污水处理，并主要从受医院活动影响的 STP 传播到环境水生基质中。
