Hokkaido University Hospital, Nishi-5 Kita-14, Kita-ku, Sapporo, Hokkaido 060-0812, Japan.
J Antimicrob Chemother. 2011 Mar;66(3):527-30. doi: 10.1093/jac/dkq487. Epub 2010 Dec 21.
The mechanism by which Escherichia coli acquires multidrug resistance genes from other bacteria in the natural environment or livestock is still unclear. The ability of ciliates to promote the transfer of genes encoding extended-spectrum β-lactamases (ESBLs) between the CTX-M-27 donor and clinically isolated recipient E. coli strains was investigated.
Equal amounts (∼10(9) cfu) of donor cefotaxime-resistant E. coli and recipient ciprofloxacin-resistant E. coli strains were mixed together in the presence or absence of 10(5) ciliates in Page's amoeba saline for 24 h, in the presence or absence of certain drugs (cytochalasin D, cycloheximide and latrunculin B).
Gene transfer frequency in the presence of ciliates was estimated at ∼10(-6); in the absence of ciliates it was ∼10(-10). Protein synthesis (cycloheximide) or phagocytosis (cytochalasin D or latrunculin B) inhibitors significantly reduced the frequency of gene transfer.
Ciliates promote the transfer of genes encoding ESBLs between E. coli strains, implying that the presence of ciliates may provide a significant impact on emerging multidrug-resistant bacteria.
大肠杆菌从自然环境或牲畜中的其他细菌获得多药耐药基因的机制尚不清楚。研究了纤毛虫促进 CTX-M-27 供体和临床分离的受体大肠杆菌菌株之间编码扩展谱β-内酰胺酶（ESBLs）的基因转移的能力。
将等量（约 10^9 cfu）的头孢他啶耐药大肠杆菌供体和环丙沙星耐药大肠杆菌受体菌株在 Page 的变形虫盐水中混合 24 小时，存在或不存在 10^5 纤毛虫，存在或不存在某些药物（细胞松弛素 D、环己酰亚胺和拉曲库滨 B）。
纤毛虫存在时的基因转移频率估计为约 10^-6；纤毛虫不存在时约为 10^-10。蛋白质合成（环己酰亚胺）或吞噬作用（细胞松弛素 D 或拉曲库滨 B）抑制剂显著降低了基因转移的频率。
纤毛虫促进了 ESBLs 编码基因在大肠杆菌菌株之间的转移，这意味着纤毛虫的存在可能对新出现的多药耐药菌产生重大影响。
