title: Detection of Staphylococcus epidermidis by a Quartz Crystal Microbalance Nucleic Acid Biosensor Array Using Au Nanoparticle Signal Amplification.
abstract: Staphylococcus epidermidis is a critical pathogen of nosocomial blood infections, resulting in significant morbidity and mortality. A piezoelectric quartz crystal microbalance (QCM) nucleic acid biosensor array using Au nanoparticle signal amplification was developed to rapidly detect S. epidermidis in clinical samples. The synthesized thiolated probes specific targeting S. epidermidis 16S rRNA gene were immobilized on the surface of QCM nucleic acid biosensor arrays. Hybridization was induced by exposing the immobilized probes to the PCR amplified fragments of S. epidermidis, resulting in a mass change and a consequent frequency shift of the QCM biosensor. To further enhance frequency shift results from above described hybridizations, streptavidin coated Au nanoparticles were conjugated to the PCR amplified fragments. The results showed that the lowest detection limit of current QCM system was 1.3×10³ CFU/mL. A linear correlation was found when the concentration of S. epidermidis varied from 1.3×10³ to 1.3×107CFU/mL. In addition, 55 clinical samples were detected with both current QCM biosensor system and conventional clinical microbiological method, and the sensitivity and specificity of current QCM biosensor system were 97.14% and 100%, respectively. In conclusion, the current QCM system is a rapid, low-cost and sensitive method that can be used to identify infection of S. epidermidis in clinical samples.
authors.affiliation: Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R China. hxia16@gmail.com.
authors.forename: Han
authors.initials: H
authors.lastname: Xia
authors.affiliation: Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R China. wangfnew@gmail.com.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R China. dr.q.huang@gmail.com.
authors.forename: Qing
authors.initials: Q
authors.lastname: Huang
authors.affiliation: Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R China. junfu_huang@yahoo.com.
authors.forename: Junfu
authors.initials: J
authors.lastname: Huang
authors.affiliation: Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R China. chenming1971@yahoo.com.
authors.forename: Ming
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R China. xiaojue21@gmail.com.
authors.forename: Jue
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R China. yao_yao24@yahoo.com.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Yao
authors.affiliation: Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R China. cqh1969@yahoo.com.cn.
authors.forename: Qinghai
authors.initials: Q
authors.lastname: Chen
authors.affiliation: The 26th Research Institute, Chinese Electronic Scientific and Technical Group Company, Chongqing 400060, P.R China. guorucai18@yahoo.com.cn.
authors.forename: Guoru
authors.initials: G
authors.lastname: Cai
authors.affiliation: Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing 400038, P.R China. weilingfu@yahoo.com.
authors.forename: Weiling
authors.initials: W
authors.lastname: Fu
keywords: Au nanoparticle; S. epidermidis; biosensor; quartz crystal microbalance