Parastan Raziey, Kargar Mohammad, Solhjoo Kavous, Kafilzadeh Farshid
Department of Microbiology, Jahrom Branch, Islamic Azad University, Jahrom, Iran; Department of Microbiology, Jahrom University of Medical Sciences, Jahrom, Iran.
Department of Microbiology, Jahrom Branch, Islamic Azad University, Jahrom, Iran.
J Glob Antimicrob Resist. 2020 Sep;22:379-385. doi: 10.1016/j.jgar.2020.02.025. Epub 2020 Mar 10.
Biofilm -forming capacity of Staphylococcus aureus (S. aureus) as a commensal opportunistic bacterial species induce a growth in antibiotic resistance in chronic diseases. Since expression of biofilm- related genes and antibiotic resistance function are interdependent, the present study was an attempt to inquire biofilm formation and its relationship with antibiotic resistance in clinical isolates.
208 S. aureus clinical isolates from four major provinces of Iran were investigated in terms of presence of adhesion genes (icaA, icaD, icaB, icaC, fnbpA, fnbpB, clfA, clfB, cna, sasC, sasG and bap) using PCR. In addition, microtiter plate (Mtp) assay was performed to examine quantitative biofilm formation of the isolates and their antibiotic resistance patterns against 16 antibiotics determined upon CLSI criteria.
The results revealed high prevalence rate (almost 100%) of icaADBC and MSCRAMMs genes in the isolates. Moreover, bap gene was not detected in any of the tested clinical isolates. Based on phenotypic method 169 isolates (81.25%) were also found to have biofilm formation ability. Among 208 isolates, 98 (47.12%) isolates were multidrug resistant (MDR). Vancomycin, linezolid, nitrofurantoin and quinupristin/dalfopristin were the most effective drugs against MDR strains. Furthermore, the findings demonstrated a significant relationship between MDR and biofilm forming capacity.
Prevalence rate of adhesion- related genes was high in S. aureus from isolates in Iran ;so these genes might be expressed under certain conditions and cause emergence of MDR strains. Therefore, further investigations are necessary to prevent initial attachment based on new candidate adhesion genes for vaccine design.
金黄色葡萄球菌作为一种共生机会性细菌，其生物膜形成能力会导致慢性疾病中抗生素耐药性增加。由于生物膜相关基因的表达与抗生素耐药功能相互依存，本研究旨在探究临床分离株中生物膜的形成及其与抗生素耐药性的关系。
采用聚合酶链反应（PCR）检测来自伊朗四个主要省份的208株金黄色葡萄球菌临床分离株中黏附基因（icaA、icaD、icaB、icaC、fnbpA、fnbpB、clfA、clfB、cna、sasC、sasG和bap）的存在情况。此外，进行微量滴定板（Mtp）试验以检测分离株的定量生物膜形成情况及其对16种抗生素的耐药模式，这些抗生素的耐药模式根据临床和实验室标准协会（CLSI）标准确定。
结果显示，分离株中icaADBC和微生物表面成分识别黏附分子（MSCRAMMs）基因的流行率很高（几乎100%）。此外，在任何测试的临床分离株中均未检测到bap基因。基于表型方法，还发现169株分离株（81.25%）具有生物膜形成能力。在208株分离株中，98株（47.12%）为多重耐药（MDR）。万古霉素、利奈唑胺、呋喃妥因和奎奴普丁/达福普汀是对抗MDR菌株最有效的药物。此外，研究结果表明MDR与生物膜形成能力之间存在显著关系。
伊朗分离株中的金黄色葡萄球菌黏附相关基因流行率很高；因此，这些基因可能在某些条件下表达并导致MDR菌株的出现。因此，有必要进一步研究，以便基于用于疫苗设计的新候选黏附基因来防止初始黏附。
