Multicenter Validation of the Analytical Accuracy of Salmonella PCR: towards an International Standard

Abstract

III, and C. L. Gyles, Mol. Cell. Probes 6:271-279, 1992), which targets the invA gene. An extended determination of selectivity by using 364 strains showed that the inclusivity was 99.6% and the exclusivity was 100% for the invA primer set. To indicate possible PCR inhibitors derived from the sample DNA, an internal amplification control (IAC), which was coamplified with the invA target gene, was constructed. In the presence of 300 DNA copies of the IAC, the detection probability for primer set 139-141 was found to be 100% when a cell suspension containing 10 4 CFU/ml was used as the template in the PCR (50 CFU per reaction). The primer set was further validated in an international collaborative study that included 16 participating laboratories. Analysis with 28 coded ("blind") DNA samples revealed an analytical accuracy of 98%. Thus, a simple PCR assay that is specific for Salmonella spp. and amplifies a chromosomal DNA fragment detected by gel electrophoresis was established through extensive validation and is proposed as an international standard. This study addresses the increasing demand of quality assurance laboratories for standard diagnostic methods and presents findings that can facilitate the international comparison and exchange of epidemiological data.

Health risk implications from simultaneous exposure to multiple environmental contaminants

“…Salmonella sp. was detected by real-time PCR targeting the invA gene (Malorny et al, 2003). Shigella sp.…”

Shiga toxin-producing Escherichia coli isolated from patients with diarrhoea in Bangladesh

“…The overnight incubated enrichment broth was also examined by PCR using stx 1 and stx 2 primers (Table 1). DNA was extracted from 1 ml broth culture by thermal cell lysis using Chelex-100 resin (Bio-Rad) (Malorny et al, 2003) and 5 ml of the DNA extract was used in the PCR. Touchdown multiplex PCR for stx 1 and stx 2 was carried out in a PTC-200 peltier thermal cycler (Bio-Rad).…”

Detection of Virulence invA Gene in the Salmonella Isolated from Fecal Samples of Poultry by Pcr Method

“…Detection of invA in all the isolates proved that they were Salmonella species (Kocabiyik, 2006) (Figure 1). The invA gene contains sequences unique to the genus Salmonella and is considered the international standard for its identification (Malorny et al, 2003). All Salmonella isolates, positive for the presence of invA gene which is responsible for invasion of cells, have the capacity to invade and survive in macrophages (Gole et al, 2013).The ability of Salmonella specific primers to detect Salmonella species rapidly and accurately is primarily due to the primer sequences that are selected from the gene invA.…”