Van Luc Tran, Hagiu Ilinca, Popovici Adelina, Marinescu Florica, Gheorghe Irina, Curutiu Carmen, Ditu Lia Mara, Holban Alina-Maria, Sesan Tatiana Eugenia, Lazar Veronica
Microbiology & Immunology Department, Faculty of Biology, University of Bucharest, 77206 Bucharest, Romania.
Research Institute of the University of Bucharest-ICUB, University of Bucharest, 050657 Bucharest, Romania.
Plants (Basel). 2022 Jul 31;11(15):2003. doi: 10.3390/plants11152003.
is a non-fermentative Gram-negative opportunistic pathogen, frequently encountered in difficult-to-treat hospital-acquired infections and also wastewaters. The natural resistance of this pathogen, together with the frequent occurrence of multidrug-resistant strains, make current antibiotic therapy inefficient in treating infections. Antibiotic therapy creates a huge pressure to select resistant strains in clinical settings but also in the environment, since high amounts of antibiotics are released in waters and soil. Essential oils (EOs) and plant-derived compounds are efficient, ecologic, and sustainable alternatives in the management of various diseases, including infections. In this study, we evaluated the antibacterial effects of four commercial essential oils, namely, tea tree, thyme, sage, and eucalyptus, on 36 strains isolated from hospital infections and wastewaters. Bacterial strains were characterized in terms of virulence and antimicrobial resistance. The results show that most strains expressed soluble pore toxin virulence factors such as lecithinase (89-100%) and lipase (72-86%). All strains were positive for alginate encoding gene and 94.44% for protease IV; most of the strains were exotoxin producers (i.e., 80.56% for the ExoS gene, 77.78% for the ExoT gene, while the ExoU gene was present in 38.98% of the strains). Phospholipase-encoding genes (plc) were identified in 91.67/86.11% of the cases (plcH/plcN genes). A high antibiotic resistance level was identified, most of the strains being resistant to cabapenems and cephalosporins. Cabapenem resistance was higher in hospital and hospital wastewater strains (55.56-100%) as compared to those in urban wastewater. The most frequently encountered encoding genes were for extended spectrum β-lactamases (ESBLs), namely, (83.33% of the strains), (80.56%), (52.78%), and (13.89%), followed by carbapenemase-encoding genes (, 8.33%). Statistical comparison of the EOs' antimicrobial results showed that thyme gave the lowest minimum inhibitory concentrations (MIC) and minimum biofilm eradication concentrations (MBEC) in -resistant isolates, making this EO a competitive candidate for the development of efficient and ecologic antimicrobial alternatives.
是一种非发酵革兰氏阴性机会致病菌，常见于难以治疗的医院获得性感染以及废水中。这种病原体的天然耐药性，加上多重耐药菌株的频繁出现，使得目前的抗生素治疗在治疗感染方面效率低下。抗生素治疗在临床环境以及环境中都产生了巨大的选择耐药菌株的压力，因为大量抗生素被释放到水和土壤中。精油（EOs）和植物衍生化合物是管理包括感染在内的各种疾病的有效、生态且可持续的替代品。在本研究中，我们评估了四种商业精油，即茶树精油、百里香精油、鼠尾草精油和桉树精油，对从医院感染和废水中分离出的36株菌株的抗菌效果。对细菌菌株进行了毒力和抗菌耐药性方面的表征。结果表明，大多数菌株表达可溶性孔毒素毒力因子，如卵磷脂酶（89 - 100%）和脂肪酶（72 - 86%）。所有菌株的藻酸盐编码基因均为阳性，蛋白酶IV为94.44%阳性；大多数菌株是外毒素产生者（即ExoS基因80.56%、ExoT基因占77.78%，而ExoU基因存在于38.98%的菌株中）。在91.67/86.11%的病例中鉴定出磷脂酶编码基因（plc）（plcH/plcN基因）。鉴定出较高的抗生素耐药水平，大多数菌株对碳青霉烯类和头孢菌素耐药。与城市废水菌株相比，医院和医院废水菌株中的碳青霉烯类耐药性更高（55.56 - 100%）。最常遇到的编码基因是超广谱β-内酰胺酶（ESBLs），即（83.33%的菌株）、（80.56%）、（52.78%）和（13.89%），其次是碳青霉烯酶编码基因（，8.33%）。精油抗菌结果的统计比较表明，百里香精油在耐药分离株中给出了最低的最低抑菌浓度（MIC）和最低生物膜根除浓度（MBEC），使这种精油成为开发高效和生态抗菌替代品的有竞争力的候选物。
