海洋蓝藻,作为海洋中广泛分布的光合自养细菌,可能有助于抗生素抗性基因(ARGs)的全球传播,并与淡水环境中的异养细菌和蓝细菌形成不同的抗菌敏感性模式。然而,关于海洋蓝藻中抗菌药物敏感性和ARGs携带的研究仍然非常有限。在这项研究中,通过现场监测和实验室调查,检查了近岸水域蓝细菌的抗生素抗性特征,其中包括PCR检测和ARG转化。结果表明,渤海湾近岸海域的海洋蓝藻与部分ARGs呈正相关。此外,大多数筛选的蓝细菌对多粘菌素显示出较高的最低抑制浓度(MIC)值,四环素,卡那霉素,和磺胺类药物,链霉素的中等MIC值,氯霉素,利福平,和诺氟沙星,罗红霉素和头孢菌素的MIC值较低。BlaTEM,blaKPC,sul1,sul2,strA,tetA,tetB,tetC,tetM,mdfA,在筛选的海洋蓝藻中检测到intI1基因。blaTEM的检出率最高(93.3%),sul1(56.6%),sul2(90%),和strA(73.3%)。四环素耐药基因中tetA的检出率最高(33.3%),和MDFA,对四环素具有抗性的多药耐药泵基因,还显示出较高的检测水平(23.3%)。总的来说,大多数筛选的海洋蓝细菌被发现能耐受海水中的多种抗生素,ARGs车厢的状况很严重。此外,筛选的海洋集胞藻。C12-2证明了通过自然转化接受RP4质粒上的ARGs的能力,并显示出对氨苄青霉素的敏感性降低,这表明某些海洋蓝藻可能通过水平基因转移从环境中获取ARGs。因此,海洋蓝藻可能在海洋ARGs的繁殖中起重要作用。
Marine cyanobacteria, as widely distributed and photosynthetically autotrophic bacteria in the ocean, may contribute to the global dissemination of antibiotic resistance genes (ARGs) and develop a different antimicrobial susceptibility pattern from heterotrophic bacteria and cyanobacteria from freshwater environments. However, studies on antimicrobial susceptibility and the carriage of ARGs in marine cyanobacteria are still very limited. In this study, the antibiotic resistance characteristics of cyanobacteria in nearshore waters were examined through field monitoring and laboratory investigations, which included PCR detection and ARG transformation. The results showed a positive correlation between marine cyanobacteria and some ARGs in the nearshore waters of Bohai Bay. Moreover, most screened cyanobacteria showed high minimum inhibitory concentration (MIC) values for polymyxins, tetracyclines, kanamycin, and sulfonamides, moderate MIC values for streptomycin, chloramphenicol, rifampicin, and norfloxacin, and low MIC values for roxithromycin and cephalosporins. The blaTEM, blaKPC, sul1, sul2, strA, tetA, tetB, tetC, tetM, mdfA, and intI1 genes were detected in the screened marine cyanobacteria. The highest detection rates were observed for blaTEM (93.3 %), sul1 (56.6 %), sul2 (90 %), and strA (73.3 %). The detection rate of tetA (33.3 %) was the highest among the tetracycline resistance genes, and mdfA, a multidrug-resistant pump gene with resistance to tetracycline, also showed a high detection level (23.3 %). Overall, most of the screened marine cyanobacteria were found to tolerate multiple antibiotics in seawater, and the condition of the ARGs carriage was serious. Furthermore, the screened marine Synechocystis sp. C12-2 demonstrated the ability to accept ARGs on the RP4 plasmid through natural transformation and showed reduced sensitivity to ampicillin, suggesting the possibility that some marine cyanobacteria could acquire ARGs from the environment through horizontal gene transfer. Thus, marine cyanobacteria may play an important role in the propagation of marine ARGs.