Radisic Vera, Grevskott Didrik H, Lunestad Bjørn Tore, Øvreås Lise, Marathe Nachiket P
Department of Contaminants and Biohazards, Institute of Marine Research, 5005, Bergen, Norway; Department of Biological Sciences, University of Bergen, 5006, Bergen, Norway.
Department of Contaminants and Biohazards, Institute of Marine Research, 5005, Bergen, Norway.
Int J Hyg Environ Health. 2023 Mar;248:114075. doi: 10.1016/j.ijheh.2022.114075. Epub 2022 Dec 13.
The aim of this study was to understand the prevalence of antibiotic resistance in Klebsiella pneumoniae present in the population in Bergen city, Norway using city-scale sewage-based surveillance, as well as the potential spread of K. pneumoniae into the marine environment through treated sewage. From a total of 30 sewage samples collected from five different sewage treatment plants (STPs), 563 presumptive K. pneumoniae isolates were obtained on Simmons Citrate Agar with myo-Inositol (SCAI) plates, and 44 presumptive K. pneumoniae isolates on SCAI plates with cefotaxime. Colistin resistance was observed in 35 isolates, while cefotaxime resistance and tigecycline resistance was observed in only five isolates each, out of 563 presumptive K. pneumoniae isolates. All 44 isolates obtained on cefotaxime-containing plates were multidrug-resistant, with 25% (n = 11) showing resistance against tigecycline. Clinically important acquired antibiotic resistance genes (ARGs), like bla, bla, qnrS1, aac(3)-IIe, tet(A), and sul1, were detected in several sequenced Klebsiella spp. isolates (n = 53). All sequenced colistin-resistant isolates (n = 13) had a mutation in the mgrB gene with nucleotide substitution at position C88T creating a premature stop codon. All sequenced tigecycline-resistant isolates (n = 4) harbored a Tet(A) variant with 22 amino acid (aa) substitutions compared to the reference protein. The sequenced K. pneumoniae isolates (n = 44) belonged to 22 different sequence types (STs) with ST730 (29.5%) as most prevalent, followed by pathogenic ST307 (11.4%). Virulence factors, including aerobactin (iutA), enterobactin (entABCDEFS and fepABCDG), salmochelin (iro), and yersiniabactin (ybt) were detected in several sequenced K. pneumoniae isolates, suggesting pathogenicity potential. Heavy metal resistance genes were common in sequenced K. pneumoniae isolates (n = 44) with silver (silABCEFPRS) and copper (pcoABDRS) resistance genes present in 79.5% of the isolates. Sewage-based surveillance can be a useful tool for understanding antibiotic resistance in pathogens present within a population and to provide up-to date information on the current resistance situation. Our study presents a framework for population-based surveillance of resistance in K. pneumoniae.
本研究的目的是利用城市规模的污水监测来了解挪威卑尔根市人群中肺炎克雷伯菌的抗生素耐药性流行情况，以及肺炎克雷伯菌通过经处理的污水向海洋环境的潜在传播。从五个不同污水处理厂（STP）采集的30份污水样本中，在含肌醇的西蒙斯柠檬酸盐琼脂（SCAI）平板上获得了563株疑似肺炎克雷伯菌分离株，在含头孢噻肟的SCAI平板上获得了44株疑似肺炎克雷伯菌分离株。在563株疑似肺炎克雷伯菌分离株中，35株分离株观察到对黏菌素耐药，而对头孢噻肟耐药和对替加环素耐药的分离株各仅5株。在含头孢噻肟平板上获得的所有44株分离株均为多重耐药，其中25%（n = 11）对替加环素耐药。在几株测序的克雷伯菌属分离株（n = 53）中检测到了临床上重要的获得性抗生素耐药基因（ARG），如bla、bla、qnrS1、aac(3)-IIe、tet(A)和sul1。所有测序的黏菌素耐药分离株（n = 13）的mgrB基因发生突变，在位置C88T处有核苷酸替换，产生一个提前终止密码子。所有测序的替加环素耐药分离株（n = 4）均携带一种Tet(A)变体，与参考蛋白相比有22个氨基酸（aa）替换。测序的肺炎克雷伯菌分离株（n = 44）属于22种不同的序列类型（ST），其中ST730（29.5%）最为常见，其次是致病性的ST307（11.4%）。在几株测序的肺炎克雷伯菌分离株中检测到了毒力因子，包括气杆菌素（iutA）、肠杆菌素（entABCDEFS和fepABCDG）、沙门菌素（iro）和耶尔森菌素（ybt），提示有致病潜力。重金属耐药基因在测序的肺炎克雷伯菌分离株（n = 44）中很常见，79.5%的分离株中存在银（silABCEFPRS）和铜（pcoABDRS）耐药基因。基于污水的监测可成为了解人群中病原体抗生素耐药性并提供当前耐药情况最新信息的有用工具。我们的研究提出了一个基于人群的肺炎克雷伯菌耐药性监测框架。
