Lung Diseases and Allergy Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran.
Department of Microbiology, Faculty of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran.
BMC Microbiol. 2022 Apr 6;22(1):89. doi: 10.1186/s12866-022-02506-0.
The capacity of antibiotics to modulate bacterial virulence has raised concerns over the appropriateness of antibiotic therapies, including when dosing strategies fall below sub-therapeutic levels. In this work, we investigated the ability of antibiotics to influence virulence in Escherichia coli isolated from urinary tract infection (UTI).
Out of 120 isolates, 32.5% carried pap, 21.7% carried hlyA, and 17.5% carried cnf. The predominant B2 phylogroup was significantly associated with the quinolone-resistant isolates. A significant association was seen between the presence of hlyA hemolysin and susceptibility to ceftriaxone and ciprofloxacin (P < 0.05). Sub-inhibitory concentrations of both antibiotics reduced the levels of hlyA expression and hemolysis in isolates treated with antibiotics compared to untreated isolates (P < 0.05). Growth rate assay showed that the decrease in hlyA expression was not an effect of decreased growth rate.
Our study indicated the inhibitory effect of ciprofloxacin and ceftriaxone on the level of hemolysis, suggesting that the sub-inhibitory concentrations of these antibiotics may affect the outcome of infections. Further studies, including animal models may elucidate the outcome of virulence modulation by these antibiotics in UTI pathogenesis.
抗生素调节细菌毒力的能力引起了人们对包括剂量策略低于治疗水平在内的抗生素治疗的适当性的关注。在这项工作中，我们研究了抗生素对尿路感染（UTI）分离的大肠杆菌毒力的影响。
在 120 株分离株中，32.5%携带 pap，21.7%携带 hlyA，17.5%携带 cnf。主要的 B2 phylogroup 与耐喹诺酮分离株显著相关。hlyA 溶血素的存在与对头孢曲松和环丙沙星的敏感性显著相关（P < 0.05）。与未处理的分离株相比，两种抗生素的亚抑菌浓度均降低了抗生素处理分离株中 hlyA 表达和溶血的水平（P < 0.05）。生长速率测定表明，hlyA 表达的降低不是生长速率降低的结果。
我们的研究表明环丙沙星和头孢曲松对溶血水平的抑制作用，表明这些抗生素的亚抑菌浓度可能影响感染的结果。包括动物模型在内的进一步研究可能阐明这些抗生素在 UTI 发病机制中对毒力调节的影响。
