Spectroscopical based techniques applied to a reliable identification of non-fermetative bacteria isolated from cystic fibrosis patients

A. MIÑÁN; A. BOSCH; C. VESCINA; B. GATTI; J. DEGROSSI; M. FRANCO; P. MONTANARO; C. VAY; O. M. YANTORNO

Villa General Belgrano, Cordoba, Argentina

Workshop; I Workshop sobre Pseudomonas y Burkholderia; 2007

Non-fermentative bacteria (NFB) are opportunistic pathogens causing infections mainly in severely ill and immune compromised patients. Pseudomonas aeruginosa is a leading cause of nosocomial infections, followed by Acinetobacter spp, Stenotrophomonas maltophilia and Alcaligenes sp. also Burkholderia cepacia complex, which is an important group of pathogens in cystic fibrosis (CF) patients. The correct identification of NFB represents a significant challenge to diagnostic laboratories. Novel genotype methodologies (16S rRNA sequence and PCR) are emerging as complements to API 20NE and other labor intensive phenotypic identification procedures as physiological and nutritional assays. We have developed the use of two new phenotypic approaches: FT-IR and MALDI-TOF spectroscopy combined with statistical multivariate analysis as alternatives to genotypic identification methods of clinically relevant isolates of NFB. In contrast to genetic techniques, sample preparation for these spectroscopical methods is simple, cheap and rapid. A rate of 97 and 99% of correct identifications down species level were obtained for FTIR and MALDI-TOF methodology respectively. We conclude that both developed methodologies could be used for classification and identification of NFB with good reproducibility and reliability in sputum samples of CF patients.