Division of Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Department of Microbiology, Qazvin University of Medical Sciences, Qazvin, Iran.
J Glob Antimicrob Resist. 2020 Dec;23:321-326. doi: 10.1016/j.jgar.2020.10.011. Epub 2020 Oct 31.
The molecular mechanisms involved in biofilm formation inStenotrophomonas maltophilia are poorly understood. Here, we examined whether the presence of smf-1, rmlA, spgM and rpfF genes is associated with biofilm formation and antibiotic resistance in S. maltophilia.
A total of 150 S. maltophilia isolates were collected from three tertiary-care hospitals in Iran and were identified through PCR amplification of the 23S rRNA gene. Biofilm formation was determined by microtitre plate assay. Presence of smf-1, rmlA, spgM and rpfF genes was examined by PCR.
Among the isolates examined, 148 (98.7%) were able to produce biofilm, of which 69 (46.0%) were strong biofilm-producers, whereas 32 (21.3%) and 47 (31.3%) were moderate and weak biofilm-producers, respectively. The frequency ofsmf-1, rmlA, spgM and rpfF was 99.3%, 98.0%, 97.3% and 70.0%, respectively. Statistical analysis indicated a direct correlation between presence of the rpfF gene and biofilm formation (P < 0.001). The high prevalence of smf-1 (99.3%) among the isolates is noted and there was a significant association between smf-1 and biofilm-forming ability (P < 0.01), but lower than rpfF. Additionally, a direct association was found between resistance to ticarcillin/clavulanate, ceftazidime, ciprofloxacin and doxycycline and strong biofilm formation in the S. maltophilia isolates (P < 0.01).
This study demonstrated thatS. maltophilia clinical isolates significantly differ in biofilm-forming ability. Moreover, presence of rpfF and smf-1, but not spgM, could be associated with biofilm formation. This study highlights the importance of rpfF in formation of biofilm compared with the other genes involved.
嗜麦芽寡养单胞菌生物膜形成的分子机制尚不清楚。本研究旨在探讨 smf-1、rmlA、spgM 和 rpfF 基因的存在是否与嗜麦芽寡养单胞菌生物膜形成和抗生素耐药性相关。
从伊朗三家三级医院共采集了 150 株嗜麦芽寡养单胞菌，通过 23S rRNA 基因 PCR 扩增进行鉴定。采用微量滴定板法测定生物膜形成情况。通过 PCR 检测 smf-1、rmlA、spgM 和 rpfF 基因的存在。
在所检测的分离株中，148 株（98.7%）能够形成生物膜，其中 69 株（46.0%）为强生物膜生成株，32 株（21.3%）和 47 株（31.3%）为中、弱生物膜生成株。smf-1、rmlA、spgM 和 rpfF 的检出率分别为 99.3%、98.0%、97.3%和 70.0%。统计分析表明 rpfF 基因的存在与生物膜形成呈正相关（P < 0.001）。分离株中 smf-1 的高检出率（99.3%）值得注意，且 smf-1 与生物膜形成能力之间存在显著相关性（P < 0.01），但低于 rpfF。此外，在嗜麦芽寡养单胞菌分离株中，对替卡西林/克拉维酸、头孢他啶、环丙沙星和强力霉素的耐药性与强生物膜形成之间存在直接相关性（P < 0.01）。
本研究表明，嗜麦芽寡养单胞菌临床分离株在生物膜形成能力方面存在显著差异。此外，rpfF 和 smf-1 的存在，但不是 spgM，可能与生物膜形成有关。本研究强调了 rpfF 与其他相关基因相比在生物膜形成中的重要性。
