Biotechnology Laboratory, Environmental Health Sciences and Research Bureau, Environmental Health Centre, Health Canada, Ottawa, Canada.
PLoS One. 2012;7(5):e37024. doi: 10.1371/journal.pone.0037024. Epub 2012 May 24.
Several Acinetobacter strains have utility for biotechnology applications, yet some are opportunistic pathogens. We compared strains of seven Acinetobacter species (baumannii, Ab; calcoaceticus, Ac; guillouiae, Ag; haemolyticus, Ah; lwoffii, Al; junii, Aj; and venetianus, Av-RAG-1) for their potential virulence attributes, including proliferation in mammalian cell conditions, haemolytic/cytolytic activity, ability to elicit inflammatory signals, and antibiotic susceptibility. Only Ah grew at 10(2) and 10(4) bacteria/well in mammalian cell culture medium at 37°C. However, co-culture with colonic epithelial cells (HT29) improved growth of all bacterial strains, except Av-RAG-1. Cytotoxicity of Ab and Ah toward HT29 was at least double that of other test bacteria. These effects included bacterial adherence, loss of metabolism, substrate detachment, and cytolysis. Only Ab and Ah exhibited resistance to killing by macrophage-like J774A.1 cells. Haemolytic activity of Ah and Av-RAG-1 was strong, but undetectable for other strains. When killed with an antibiotic, Ab, Ah, Aj and Av-RAG-1 induced 3 to 9-fold elevated HT29 interleukin (IL)-8 levels. However, none of the strains altered levels of J774A.1 pro-inflammatory cytokines (IL-1β, IL-6 and tumor necrosis factor-α). Antibiotic susceptibility profiling showed that Ab, Ag and Aj were viable at low concentrations of some antibiotics. All strains were positive for virulence factor genes ompA and epsA, and negative for mutations in gyrA and parC genes that convey fluoroquinolone resistance. The data demonstrate that Av-RAG-1, Ag and Al lack some potentially harmful characteristics compared to other Acinetobacter strains tested, but the biotechnology candidate Av-RAG-1 should be scrutinized further prior to widespread use.
七种不动杆菌（Acinetobacter）菌株在生物技术应用中有一定的用途，但其中一些也是机会性病原体。我们比较了七种不动杆菌（baumannii、Ab；calcoaceticus、Ac；guillouiae、Ag；haemolyticus、Ah；lwoffii、Al；junii、Aj；和venetianus、Av-RAG-1）菌株的潜在毒力属性，包括在哺乳动物细胞条件下的增殖、溶血/细胞溶解活性、引发炎症信号的能力和抗生素敏感性。只有 Ah 在 37°C 的哺乳动物细胞培养基中以 10(2)和 10(4)个细菌/孔的速度生长。然而，与结肠上皮细胞（HT29）共培养可以提高除 Av-RAG-1 以外的所有细菌菌株的生长。Ab 和 Ah 对 HT29 的细胞毒性至少是其他测试细菌的两倍。这些影响包括细菌粘附、代谢丧失、基质脱落和细胞溶解。只有 Ab 和 Ah 表现出对巨噬细胞样 J774A.1 细胞杀伤的抗性。Ah 和 Av-RAG-1 的溶血活性很强，但其他菌株则无法检测到。当用抗生素杀死时，Ab、Ah、Aj 和 Av-RAG-1 诱导 HT29 白细胞介素（IL）-8 水平升高 3 到 9 倍。然而，没有一种菌株改变 J774A.1 促炎细胞因子（IL-1β、IL-6 和肿瘤坏死因子-α）的水平。抗生素敏感性分析显示，Ab、Ag 和 Aj 在低浓度的一些抗生素下仍具有活力。所有菌株的 ompA 和 epsA 毒力因子基因均为阳性，而 gyrA 和 parC 基因突变导致氟喹诺酮耐药则为阴性。数据表明，与测试的其他不动杆菌菌株相比，Av-RAG-1、Ag 和 Al 缺乏一些潜在的有害特征，但生物技术候选物 Av-RAG-1 在广泛使用之前应进一步仔细审查。
