| High efficiency detection and identification of two E. coli strains and two Staphylococcus aureus strains was accomplished using surface enhanced Raman scattering (SERS) method. Finally, it provided a rapid and effective identification method for the identification and classification of clinical bacteria. For detecting bacteria SERS nano silver sol was prepared by microwave method, and using MRSA (Methicillin resistant Staphylococcus aureus) as test samples to optimize the silver sol and the broth volume ratio, reaction time, the optimal testing conditions were obtained as follows: silver colloids and bacteria (Maxwell turbidity 0.5) volume ratio was 1:2, the reaction time one hour, applied in SERS detection of two E. coli JM109, DH5α and two S. aureus ATCC25923, MRSA, and the belonging to the corresponding peaks. The experiments were selected 30 cases of E. coli JM109, DH5α, and 30 cases of S. aureus ATCC25923 and MRSA as the training set, 6 cases of E. coli JM109, DH5α and 6 cases of S. aureus ATCC25923 and MRSA as the testing set, based on principal component analysis (PCA) combined with linear discriminant analysis (LDA) model. The results showed that the correct classification rate of JM109, DH5α training set was at 93.33%, ATCC25923, the correct classification rate of MRSA training set was at 76.67%, the correct classification rate of spanless set were respectively at 91.67%, 75%. The nano silver sol as the enhanced medium showed different bacterial SERS atlases. When using this discriminant model, it was better to distinguish different kinds of bacteria, but for the same bacterial species, the identification effect of common bacteria and drug resistant bacteria was relatively poor. This study had important guiding significance for the rapid and accurate identification and classification of bacteria in clinic. |
