New approaches to identification of bacterial pathogens by surface enhanced laser desorption/ionization time of flight mass spectrometry in concert with artificial neural networks, with special reference to Neisseria gonorrhoeae

Abstract

Surface enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF MS) has been applied in large numbers of oncological studies but the microbiological field has not been extensively explored to date. This paper describes the application of SELDI-TOF MS in concert with a multi-layer perceptron artificial neural network (ANN) with a back propagation algorithm for the identification of Neisseria gonorrhoeae. N. gonorrhoeae, the aetiological agent of gonorrhoea, is the second most common sexually transmitted disease in the UK and USA. Analysis of over 350 strains of N. gonorrhoeae and closely related species by SELDI-TOF MS facilitated the design of an ANN model and revealed 20 ion peak descriptors of positive, negative and secondary nature that were paramount for the identification of the pathogen. The model performed with over 96 % efficiency when based on these 20 ion peak descriptors and exhibited a sensitivity of 95 . 7 % and a specificity of 97 . 1 %, with an area under the curve value of 0 . 996. The technology has the potential to link several ANN models for a comprehensive rapid identification platform for clinically important pathogens.

Sample preparation methods for MALDI‐MS profiling of bacteria

“…This method, enhanced using in addition a hydrophobic affinity surface, resulted in the possibility of analyzing F. tularensis strains within the sub-species discrimination (Seibold et al, 2007). Schmid et al (2005) were able to distinguish 350 extracts of Neisseria gonorrhoeae from closely related species with a sensitivity of 95.7% and a specificity of 97.1% after the SELDI-MS using hydrophobic ProteinChips. Yang et al (2009) were able to distinguish correctly 62 of 63 S. aureus isolates from other staphylococci after the SELDI-MS on AU ProteinChips.…”

Direct Bacterial Profiling by Matrix-Assisted Laser Desorption−Ionization Time-of-Flight Mass Spectrometry for Identification of Pathogenic Neisseria

“…Mass spectrometry based methods seem to be most promising in this field. Recently, Oliver Schmid et al, 2005, used surface enhanced laser desorption/ionization-time of flight mass spectrometry in combination with artificial neural networks for the identification of N. gonorrhoeae. 23 In addition the automated comparative sequence analysis by basespecific cleavage and mass spectrometry was used for N. meningitidis typing.…”

“…Recently, Oliver Schmid et al, 2005, used surface enhanced laser desorption/ionization-time of flight mass spectrometry in combination with artificial neural networks for the identification of N. gonorrhoeae. 23 In addition the automated comparative sequence analysis by basespecific cleavage and mass spectrometry was used for N. meningitidis typing. 24 The challenge of our investigation was to apply a MALDI-TOF mass spectrometry technique for species identification of closely related bacteria from the genus Neisseria.…”

Advances in mass spectrometry for the identification of pathogens

“…Surface-enhanced laser desorption/ionization (SELDI), a modified version of MALDI-TOFMS, has been successfully used for biomarker discovery and protein fingerprinting of bacterial species (Barzaghi et al, 2004;Lancashire et al, 2005;Lundquist et al, 2005;Schmid et al, 2005;Al Dahouk et al, 2006). Hutchens et al first described the original concept of SELDI .…”