Surface-enhanced Raman spectroscopy for the identification of tigecycline-resistant E. coli strains

Author：Saba Bashir a , Haq Nawaz a,⇑ , Muhammad Irfan Majeed a,⇑ , Mashkoor Mohsin b,⇑ , Ali Nawaz b , Nosheen Rashid c , Fatima Batool a , Saba Akbar a , Muhammad Abubakar a , Shamsheer Ahmad a , Saqib Ali a , Muhammad Kashif a

ABSTRACT：Tigecycline (TGC) is recognised as last resort of drugs against several antibiotic-resistant bacteria. Bacterial resistance to tigecycline due to presence of plasmid-mediated mobile TGC resistance genes (tet X3/X4) has broken another defense line. Therefore, rapid and reproducible detection of tigecyclineresistant E. coli (TREC) is required. The current study is designed for the identification and differentiation of TREC from tigecycline-sensitive E. coli (TSEC) by employing SERS by using Ag NPs as a SERS substrate. The SERS spectral fingerprints of E. coli strains associated directly or indirectly with the development of resistance against tigecycline have been distinguished by comparing SERS spectral data of TSEC strains with each TREC strain. Moreover, the statistical analysis including Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA) and Partial Least Squares-Discriminant Analysis (PLS-DA) were employed to check the diagnostic potential of SERS for the differentiation among TREC and TSEC strains. The qualitative identification and differentiation between resistant and sensitive strains and among individual strains have been efficiently done by performing both PCA and HCA. The successful discrimination among TREC and TSEC at the strain level is performed by PLS-DA with 98% area under ROC curve, 100% sensitivity, 98.7% specificity and 100% accuracy.

Keywords:Surface Enhanced Raman Spectroscopy Discriminant analysis Escherichia coli Tigecycline resistance

关联产品：ATR8300-全自动对焦激光显微拉曼光谱扫描成像仪