Artificial neural network-assisted Fourier transform infrared spectroscopy for differentiation ofSalmonellaserogroups and its application on epidemiological tracing ofSalmonellaBovismorbificans outbreak isolates from fresh sprouts

Abstract

Salmonellae represent one of the most common bacterial infection reagents in both humans and animals. For detection and epidemiological elucidation of Salmonella infections, determination of Salmonella serotypes and differentiation between different Salmonella isolates is crucial. In the first part of this study, Artificial Neural Network (ANN)-assisted Fourier transform infrared (FTIR) spectroscopy was used to establish a method for subtyping Salmonella isolates according to their serogroups. For this, 290 Salmonella strains from 35 different serogroups were used to establish an ANN for differentiation between infrared spectra of 10 different Salmonella serogroups (B, C1, C2-C3, D1/D2, E1, E4, F, G, H, O:55) vs. the remaining serogroups. In the final ANN, sensitivity values ranged between 90 and 100% for most of the 10 serogroups under investigation. In the second part of this study, ANN-assisted FTIR spectroscopy was applied for epidemiological distinction of Salmonella Bovismorbificans outbreak isolates from fresh sprouts vs. isolates from other sources. Four Salmonella Bovismorbificans isolates from human and food origin in the context of a Southern German outbreak were successfully discriminated from other S. Bovismorbificans isolates from various sources. ANN-assisted FTIR spectroscopy is thus an effective tool for discrimination of Salmonella isolates at or even below serogroup level.

A Simple, Label-Free, and High-Throughput Method to Evaluate the Epigallocatechin-3-Gallate Impact in Plasma Molecular Profile

“…The present work aimed to evaluate the impact of EGCG consumption on the plasma molecular profile as obtained from high-throughput Fourier transform infrared (FTIR) spectroscopy, a very sensitive and specific technique. Examples of the technique's high sensitivity can be observed in applications to discriminate similar cells as bacteria serogroups from Salmonella [17], stem cell differentiation [18], cancer diagnosis and cancer grading [19,20], and to conduct diagnosis and prognosis of a diverse range of other diseases and the monitoring of treatments efficiency [21][22][23]. The high versatility of this technique also enables its application to a high diversity of biological samples, from tissue-based biopsies to body fluids such as urine, saliva, and tears [23][24][25].…”

Countrywide multi-serotype outbreak of Salmonella Bovismorbificans ST142 and monophasic Salmonella Typhimurium ST34 associated with dried pork sausages in France, September 2020* to January 2021

“…The outbreak here presented reflects an increase of 40% over the average in 2020. This serotype has been often involved in human outbreaks in recent years, mostly associated to the consumption of vegetables like alfalfa sprouts, salads, hummus or tahini in Australia, Finland, Switzerland, Germany and the United States [7][8][9][10][11]. However, the association of S. Bovismorbificans with pork products has been described previously, in the Netherlands in 2017 [13].…”

“…enterica serotype Bovismorbificans is a relatively frequent food-borne pathogen (57 cases/year in France from 2012-20, and it was the 13 th most frequently isolated serotype among humanidentified Salmonella infections in Europe in 2019 [2]. Serotype Bovismorbificans is often identified in association with consumption of contaminated vegetables [7][8][9][10][11]. However, it has also been recently involved in outbreaks linked to horse and pork meat in Australia and France [12,13].…”

Discrimination of bacteria using whole organism fingerprinting: the utility of modern physicochemical techniques for bacterial typing

“…Other authors have also illustrated the ability of FT-IR coupled with robust chemometrics to discriminate between different infectious Listeria spp. 66 , lactic acid bacteria 67 , Salmonella 68 and Pectobacterium and Dickeya spp.. 69 These studies clearly demonstrate that FT-IR spectroscopy is capable of classifying and differentiating between medically and industrially important bacteria and other microorganisms at various taxonomic levels, which are important prerequisites for appropriate patient management and protection of public health.…”