Identification ofYersinia ruckerifrom diseased salmonid fish by Fourier transform infrared spectroscopy

Abstract

Yersinia ruckeri is the causative agent of enteric redmouth disease (ERM), which mainly affects salmonid fish. Isolates of Y. ruckeri from diseased salmonid fish were obtained over a 6-year period from eight fish farms in the State of Baden-Württemberg, Southwest Germany. The strains were characterized by biochemical methods and Fourier transform infrared spectroscopy (FT-IR) combined with artificial neural network analysis. These methods were complemented by 16S rDNA sequencing for several isolates. The set of strains from these fish farms included sorbitol-positive, gelatinase-positive and non-motile Y. ruckeri. These variants were differentiated with an advanced FT-IR module, which is part of a higher-ranking method including more than 200 well-defined Yersinia strains against a background of more than 1000 other Gram-negative isolates. Validation of the newly constructed method yielded 97.4% of Y. ruckeri identified correctly on the species level. Thus, the FT-IR analysis enables distinction of all Y. ruckeri from other Yersinia species (e.g. fish-borne Y. enterocolitica) and other Enterobacteriaceae typically misidentified because of similar biochemical reaction profiles, especially Hafnia alvei. The differentiation of sorbitol-positive variants of Y. ruckeri using FT-IR was demonstrated.

Yersinia enterocolitica in Diagnostic Fecal Samples from European Dogs and Cats: Identification by Fourier Transform Infrared Spectroscopy and Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

“…Bacterial isolates were cultivated independently in three replicates at 37°C for 24 h on sheep blood agar plates (Oxoid). Harvesting of cells, sample preparation, and the examination of the dried bacterial films by FT-IR spectroscopy were performed as described previously for Yersinia differentiation (12,39). The infrared spectra were recorded for each sample in a transmission mode in the wave number range of 500 to 4,000 cm Ϫ1 with a FT-IR spectrometer (IFS 28/B; BrukerOptics, Ettlingen, Germany).…”

“…Acquisition and analysis of data were carried out by using OPUS software (version 4.2; BrukerOptics) and an artificial neural network built by NeuroDeveloper software (Synthon, Heidelberg, Germany) (40). Differentiation was performed with an updated version of a method described previously (12,39). This method allows for species differentiation of Y. enterocolitica independently of the presence or absence of the ail gene.…”

An Overview of the Evolution of Infrared Spectroscopy Applied to Bacterial Typing

“…Species FTIRS HCA, ANN, PCA, SIMCA [45,49,53,86,92] Stenotrophomonas maltophilia Species FTIRS PCA, ANN [45,55] Ralstonia pickettii Species FTIRS ANN [45] Achromobacter spp Species FTIRS ANN [45] Yersinia spp. Species FTIRS, FTIRS-ATR ANN, SIMCA, PCA, CVA [47,50,52] Yersinia enterocolitica Serotype FTIRS ANN [47] Biotype FTIRS ANN [47] Yersinia ruckeri Biotype FTIRS ANN [80] Oscillatoria limosa Species FTIRS-ATR PCA, ANN [48] Arthrospira platensis Species FTIRS-ATR PCA, ANN [48] Phormidium spp. Species FTIRS-ATR PCA, ANN [48] Scytonem javanicum Species FTIRS-ATR PCA, ANN [48] Nostoc punctiform Species FTIRS-ATR PCA, ANN [48] Salmonella spp.…”

“…IR spctroscopy proved also to be able to discriminate Brucella spp. isolates according to their biovars, [78] Xanthomonas oryzae pathovars, [79] B. cepacia complex species ribopatterns, [46] L. monocytogenes halotypes, [57] Y. enterocolitica and Yersinia ruckeri biotypes, [47,80] S. enterica serovar Enteritidis phage types, [81] and Campilobacter spp. genotypes.…”

IR and Raman Spectroscopy for Pathogen Detection

“…Since then, FT-IR spectroscopy has been successfully used to study, among others, biofilm formation, cellular components in bacteria, microbial response to stress, injury, and inactivation, as well as the development of antibiotic resistance [16][17][18]. Emphasis was also placed on the detection, discrimination, classification, and identification of bacteria -especially foodborne pathogens -such as Bacillus [19,20], Brucella [21], cyanobacteria [22], E. coli [23,24], lactobacilli [25], Listeria [26,27], Mycobacteria [28], Streptococcus [29], Salmonella [30,31], Staphylococcus [32,33], and Yersinia [34,35]. Also nosocomial pathogens, such as the members of the Burkholderia cepacia complex [36][37][38] possible warfare agents [39], and even fungi [40] were investigated.…”