Comprehensive analysis of Salmonella sequence polymorphisms and development of a LDR-UA assay for the detection and characterization of selected serotypes

Abstract

Salmonella is a major cause of food-borne disease, and Salmonella enterica subspecies I includes the most clinically relevant serotypes. Salmonella serotype determination is important for the disease etiology assessment and contamination source tracking. This task will be facilitated by the disclosure of Salmonella serotype sequence polymorphisms, here annotated in seven genes (sefA, safA, safC, bigA, invA, fimA, and phsB) from 139 S. enterica strains, of which 109 belonging to 44 serotypes of subsp. I. One hundred nineteen polymorphic sites were scored and associated to single serotypes or to serotype groups belonging to S. enterica subsp. I. A diagnostic tool was constructed based on the Ligation Detection Reaction-Universal Array (LDR-UA) for the detection of polymorphic sites uniquely associated to serotypes of primary interest (Salmonella Hadar, Salmonella Infantis, Salmonella Enteritidis, Salmonella Typhimurium, Salmonella Gallinarum, Salmonella Virchow, and Salmonella Paratyphi B). The implementation of promiscuous probes allowed the diagnosis of ten further serotypes that could be associated to a unique hybridization pattern. Finally, the sensitivity and applicability of the tool was tested on target DNA dilutions and with controlled meat contamination, allowing the detection of one Salmonella CFU in 25 g of meat.

Genome Sequence of the Salmonella enterica subsp. enterica Serovar Namur Strain 05-2929, Lacking the Salmonella Atypical Fimbrial Operon

“…This annotation confirmed the deletion of the entire saf operon in this S. Namur strain. Strains of other subspecies I serovars lacking safC have been reported previously (6). Moreover, based on the presence and absence of clade-specific genes and previously identified single nucleotide polymorphisms (7), this S. Namur strain can be further classified as an S. enterica subsp.…”

Detection of Shigella in Milk and Clinical Samples by Magnetic Immunocaptured-Loop-Mediated Isothermal Amplification Assay

“…Shigella is recognized as an important bacterial pathogen worldwide, and may cause several diseases, such as purulent blood, diarrhea, spasms, and shocks, which leads a huge threat to society ( Iseki et al, 2007 ). There are about 1.8 million patients died for diarrhea and a majority of these cases (160 million cases per year) have been attributed to Shigella ( Lauri et al, 2011 ).…”

Rapid and Sensitive Detection of Shigella spp. and Salmonella spp. by Multiple Endonuclease Restriction Real-Time Loop-Mediated Isothermal Amplification Technique

“…were associated with the majority of cases of bacillary dysentery prevalent in developing nations, and Salmonella spp. were the most common cause of food-borne infection outbreaks in almost all countries (Iseki et al, 2007 ; Lin et al, 2010 ; Lauri et al, 2011 ). Therefore, for food industry and public health, rapid, specific and sensitive methodologies to detect the pathogens are continuously required.…”