Masalane Naledi S, Bester Linda A, Ismail Arshad, Essack Sabiha Y, Mbanga Joshua
Antimicrobial Research Unit, College of Health Sciences, University of Kwazulu-Natal, Private Bag X54001, Durban, 4000, South Africa.
Biomedical Resource Unit, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa.
BMC Microbiol. 2025 May 11;25(1):284. doi: 10.1186/s12866-025-03987-5.
The application of wastewater-based epidemiology has gained traction as a cost effective tool in antimicrobial resistance (AMR) surveillance with studies showing a correlation between the presence of resistant bacteria from hospital sewage and patients. This study compared Klebsiella pneumoniae from patients and hospital effluent in terms of antibiotic resistance patterns, antibiotic resistance genes (ARGs), mobile genetic elements (MGEs) and phylogenomic relationships.
Pooled effluent samples were collected from the final effluent point of a regional hospital and K. pneumoniae isolates were identified on selective media. Clinical isolates were also collected from the same hospital. Antimicrobial susceptibility testing (AST) was performed using the VITEK® 2 system. DNA was extracted prior to whole genome sequencing (WGS). The resistome, mobilome, and phylogenetic lineages of sequenced isolates were assessed using bioinformatics analysis. A total of 10 randomly selected presumptive and 10 clinical K. pneumoniae constituted the sample and were subjected to AST. Total resistance was observed in the clinical samples to cefuroxime, cefotaxime, piperacillin/tazobactam, gentamicin, tobramycin and trimethoprim/sulfamethoxazole. The effluent isolates exhibited total susceptibility to most antibiotics but showed resistance to amoxicillin/clavulanic acid and piperacillin/tazobactam (100%), and tigecycline (10%). The effluent isolates did not exhibit a diverse resistome, while the clinical isolates harboured genes conferring resistance to aminoglycoside (aph(6)-Id, aph(3'')-Ib, aac(6')-Ib-cr, aadA16), ß-lactam (bla group, bla group, bla group), and fluoroquinolone (oqxA, oqxB) antibiotics. Only class 1 integrons were identified. Phylogenetic analysis revealed that effluent isolates from this study were not closely related to the clinical isolates.
This study showed no correlation between the resistance profiles of the clinical and effluent isolates. The relationship between AMR in hospital effluent and clinical resistance may depend on the antimicrobial agents and bacterial species studied.
基于废水的流行病学作为一种具有成本效益的抗菌药物耐药性（AMR）监测工具已受到关注，研究表明医院污水中的耐药菌与患者之间存在相关性。本研究比较了患者和医院污水中的肺炎克雷伯菌在抗生素耐药模式、抗生素耐药基因（ARGs）、移动遗传元件（MGEs）和系统发育关系方面的差异。
从一家地区医院的最终排放点收集混合污水样本，并在选择性培养基上鉴定肺炎克雷伯菌分离株。临床分离株也从同一家医院收集。使用VITEK® 2系统进行抗菌药物敏感性测试（AST）。在全基因组测序（WGS）之前提取DNA。使用生物信息学分析评估测序分离株的耐药基因组、可移动基因组和系统发育谱系。总共10株随机选择的推定肺炎克雷伯菌和10株临床肺炎克雷伯菌构成样本并进行AST。临床样本对头孢呋辛、头孢噻肟、哌拉西林/他唑巴坦、庆大霉素、妥布霉素和甲氧苄啶/磺胺甲恶唑表现出完全耐药。污水分离株对大多数抗生素表现出完全敏感，但对阿莫西林/克拉维酸和哌拉西林/他唑巴坦（100%）以及替加环素（10%）表现出耐药。污水分离株没有表现出多样化的耐药基因组，而临床分离株携带赋予对氨基糖苷类（aph(6)-Id、aph(3'')-Ib、aac(6')-Ib-cr、aadA16）、β-内酰胺类（bla组、bla组、bla组）和氟喹诺酮类（oqxA、oqxB）抗生素耐药的基因。仅鉴定出1类整合子。系统发育分析表明，本研究中的污水分离株与临床分离株没有密切关系。
本研究表明临床分离株和污水分离株的耐药谱之间没有相关性。医院污水中的AMR与临床耐药性之间的关系可能取决于所研究的抗菌药物和细菌种类。
