Cirkovic Ivana, Muller Bruno H, Janjusevic Ana, Mollon Patrick, Istier Valérie, Mirande-Meunier Caroline, Brkic Snezana
Institute of Microbiology and Immunology, Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia.
bioMérieux, R&D Microbiology, Sequencing Platform, F-69280 Marcy-l'Étoile, France.
Antibiotics (Basel). 2023 Feb 8;12(2):350. doi: 10.3390/antibiotics12020350.
Wastewater (WW) is considered a source of antibiotic-resistant bacteria with clinical relevance and may, thus, be important for their dissemination into the environment, especially in countries with poor WW treatment. To obtain an overview of the occurrence and characteristics of carbapenem-resistant Gram-negative bacteria (CR-GNB) in WW of Belgrade, we investigated samples from the four main sewer outlets prior to effluent into international rivers, the Sava and the Danube. Thirty-four CR-GNB isolates were selected for antimicrobial susceptibility testing (AST) and whole-genome sequencing (WGS). AST revealed that all isolates were multidrug-resistant. WGS showed that they belonged to eight different species and 25 different sequence types (STs), seven of which were new. ST101 () with novel plasmid p101_srb was the most frequent isolate, detected at nearly all the sampling sites. The most frequent resistance genes to aminoglycosides, quinolones, trimethroprim-sulfamethoxazole, tetracycline and fosfomycin were (6')-Ib-cr (55.9%), A (32.3%), (47.1%), 1 (52.9%), (A) (23.5%) and A (50%), respectively. Acquired resistance to colistin via chromosomal-mediated mechanisms was detected in (mutations in and ) and (mutation in ), while a plasmid-mediated mechanism was confirmed in the complex ( gene). The highest number of virulence genes (>300) was recorded in isolates. Further research is needed to systematically track the occurrence and distribution of these bacteria so as to mitigate their threat.
废水被认为是具有临床相关性的抗生素耐药菌的一个来源，因此，对于这些耐药菌传播到环境中可能很重要，尤其是在污水处理水平较差的国家。为了全面了解贝尔格莱德废水中耐碳青霉烯类革兰氏阴性菌（CR-GNB）的发生情况和特征，我们调查了四个主要下水道出口在污水排入国际河流萨瓦河和多瑙河之前的样本。选择了34株CR-GNB分离株进行药敏试验（AST）和全基因组测序（WGS）。AST结果显示所有分离株均为多重耐药。WGS表明它们属于8个不同的菌种和25种不同的序列类型（STs），其中7种是新的。携带新型质粒p101_srb的ST101（）是最常见的分离株，几乎在所有采样点都能检测到。对氨基糖苷类、喹诺酮类、甲氧苄啶-磺胺甲恶唑、四环素和磷霉素最常见的耐药基因分别为（6'）-Ib-cr（55.9%）、A（32.3%）、（47.1%）、1（52.9%）、（A）（23.5%）和A（50%）。在（和中的突变）和（中的突变）中检测到通过染色体介导机制获得的对黏菌素的耐药性，而在复合体（基因）中证实了质粒介导机制。在分离株中记录到的毒力基因数量最多（>300个）。需要进一步开展研究，系统追踪这些细菌的发生和分布情况，以减轻它们造成的威胁。
