Department of Microbiology and Immunology, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605, Japan.
Sci Rep. 2021 Jun 3;11(1):11700. doi: 10.1038/s41598-021-90732-3.
We investigated the antimicrobial effects of colistin (CST) and tigecycline (TGC), either alone or in combination, on biofilm-dispersed and biofilm-embedded multidrug-resistant Acinetobacter baumannii (MDRAB) strains R1 and R2. The bacterial growth of biofilm-dispersed MDRAB was inhibited by CST or TGC. However, the inhibitory effects were attenuated by a combination of CST and low concentrations of TGC. The bactericidal effects of CST, but not TGC, were observed on biofilm-dispersed MDRAB. Notably, the bactericidal effects increased with a combination of CST and high concentrations of TGC, whereas they were attenuated with the combination of CST and low concentrations of TGC. Although biofilm formation by MDRAB decreased with increasing concentrations of CST or TGC, there was no complete disruption of the biofilms. Additionally, the biofilms increased with a combination of 1-2 μg/mL CST and TGC at 2 μg/mL and 2-4 μg/mL for strains R1 and R2, respectively. Biofilm-embedded MDRAB was eradicated with CST, but not TGC. Notably, the eradication effects increased with a combination of CST and high concentrations of TGC, whereas attenuation happened with the combination of CST and low concentrations of TGC. These results provide information on the combined effects of CST and TGC in the treatment of biofilm-associated MDRAB infection.
我们研究了多粘菌素（CST）和替加环素（TGC）单独或联合应用对生物膜分散和嵌入的多药耐药鲍曼不动杆菌（MDRAB）菌株 R1 和 R2 的抗菌作用。CST 或 TGC 抑制生物膜分散的 MDRAB 的细菌生长。然而，CST 和低浓度 TGC 的联合使用减弱了抑制作用。CST 对生物膜分散的 MDRAB 具有杀菌作用，但 TGC 没有。值得注意的是，CST 和高浓度 TGC 的联合使用增加了杀菌作用，而 CST 和低浓度 TGC 的联合使用则减弱了杀菌作用。尽管 CST 或 TGC 浓度的增加降低了 MDRAB 的生物膜形成，但生物膜并没有完全被破坏。此外，生物膜在 CST 与 TGC 的联合作用下增加，对于菌株 R1 和 R2，分别在 CST 1-2μg/mL 和 TGC 2-4μg/mL 时增加。CST 可以根除生物膜嵌入的 MDRAB，但 TGC 不能。值得注意的是，CST 和高浓度 TGC 的联合使用增加了根除作用，而 CST 和低浓度 TGC 的联合使用则减弱了根除作用。这些结果提供了 CST 和 TGC 联合应用治疗生物膜相关 MDRAB 感染的信息。
