Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Bacteriology and Virology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Bacteriology and Virology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
Microb Pathog. 2021 May;154:104860. doi: 10.1016/j.micpath.2021.104860. Epub 2021 Mar 23.
Staphylococcus aureus (S. aureus) is a bacterial pathogen can cause a wide range of nosocomial infections. Nasal colonization by S.aureus plays important role both in the epidemiology and pathogenesis of infection.
The purpose of this study was to investigate the association of clinical isolates and nasal colonizers of S. aureus in the same patients by molecular methods, and their antibiotic susceptibility pattern.
A total of 181 S. aureus isolates were collected from 100 patients admitted that including 100 clinical isolates and 81 nasal swabs from the same patients (19 cases were found as noncarriers). Superantigens and adhesion genes were identified by PCR. Molecular typing of the isolates was performed by repetitive element polymerase chain reaction (Rep-PCR). Antimicrobial susceptibility pattern of the isolates was conducted by disk diffusion. MIC of the isolates to vancomycin was determined by microbroth dilution. The ability of S. aureus isolates to form biofilm was determined by microtiter plate assay.
The most frequent adhesion gene in both clinical isolates and nasal colonizer was clfA with 93% and 76%, respectively. Staphylococcal enterotoxin A (SEA) was the most commonly superantigen (68%) in both nasal colonizers (71.6%) and clinical isolates (65%). The highest resistance rate was to erythromycin (45.3%) with 36% and 56.8% in clinical and nasal colonizer isolates, respectively. All S. aureus isolates were susceptible to linezolid and vancomycin. Multiple drug resistance (MDR) was detected in 36% (n = 65) of the isolates. Biofilm formation was identified in 160 (88.4%) isolates with 87% and 90% in clinical isolates and nasal colonizers, respectively. Repetitive element polymerase chain reaction (Rep-PCR) typing divided 181 S. aureus isolates into six clusters. Twelve isolates from clinical isolates and nasal carriers were closely related.
There is a high concordance rate between colonizing and clinical isolates of S. aureus in terms of adhesion factors and superantigen genes. It is suggested that nasal decolonization could be effective in the preventing of S. aureus infections.
金黄色葡萄球菌（S. aureus）是一种细菌病原体，可引起广泛的医院感染。金黄色葡萄球菌鼻腔定植在感染的流行病学和发病机制中起着重要作用。
本研究旨在通过分子方法研究同一患者的临床分离株和鼻腔定植株金黄色葡萄球菌之间的关系及其抗生素敏感性模式。
共从 100 名住院患者中采集了 181 株金黄色葡萄球菌分离株，其中包括 100 株临床分离株和 81 株来自同一患者的鼻腔拭子（19 例为非定植者）。通过 PCR 鉴定超抗原和粘附基因。采用重复元件聚合酶链反应（Rep-PCR）对分离株进行分子分型。采用纸片扩散法检测分离株的抗生素敏感性模式。采用微量肉汤稀释法测定分离株对万古霉素的 MIC。采用微量滴定板法测定金黄色葡萄球菌分离株形成生物膜的能力。
临床分离株和鼻腔定植株中最常见的粘附基因均为 clfA，分别为 93%和 76%。葡萄球菌肠毒素 A（SEA）是两种鼻腔定植株（71.6%）和临床分离株（65%）中最常见的超抗原（68%）。红霉素的耐药率最高（45.3%），临床分离株和鼻腔定植株的耐药率分别为 36%和 56.8%。所有金黄色葡萄球菌分离株均对利奈唑胺和万古霉素敏感。36%（n=65）的分离株检测到多重耐药（MDR）。160 株（88.4%）分离株可形成生物膜，临床分离株和鼻腔定植株的生物膜形成率分别为 87%和 90%。重复元件聚合酶链反应（Rep-PCR）分型将 181 株金黄色葡萄球菌分离株分为 6 个聚类。12 株来自临床分离株和鼻腔定植株的分离株密切相关。
金黄色葡萄球菌在粘附因子和超抗原基因方面，定植株与临床分离株之间存在高度一致性。鼻腔去定植可能对预防金黄色葡萄球菌感染有效。
