Development of PCR-based identification of Salmonella enterica serovars

Abstract

The aim of the study was to evaluate and adapt the PCR-based protocol that utilizes the developed serotype-specifi c primers to identify Salmonella enterica species and its serotypes that are most frequently isolated from poultry samples in Vojvodina. Using the slide agglutination test, 64 and 33 out of 107 Salmonella isolates were identifi ed as S. Infantis and S. Enteritidis, respectively, while ten isolates were identifi ed as eight different Salmonella serovars. Using the same isolates, presence of 993-bp (bcfC gene), 636-bp (steB gene) and 293-bp (sdf locus) amplicons in multiplex PCR unambiguously identifi ed 31 isolates as S. Enteritidis. Two isolates identifi ed as Enteritidis in slide agglutination test were not identifi ed as such in PCR-based approach since they both were missing 293-bp long PCR product. Thirty-nine isolates produced a 727-bp amplicon in the specifi c simplex PCR, and thus were identifi ed as S. Infantis. The greatest discrepancy in comparison to the results of conventional serotyping has been observed in the case of S. Infantis, since 25 more isolates were noted as S. Infantis by conventional serotyping. Seven isolates, with unexpected PCR profi les stayed unidentifi ed by molecular typing, although they were serotyped as S. Typhimurium (1) and S. Infantis (6). S. Gallinarum serovar has to be additionally confi rmed, since it shares the same PCR profi le with S. Livingstone. Clearly, PCR-based identifi cation has to be thoroughly checked, verifi ed and adapted if it is to be applied as the routine identifi cation protocol.

Hunted Wild Boars in Sardinia: Prevalence, Antimicrobial Resistance and Genomic Analysis of Salmonella and Yersinia enterocolitica

“…For the detection of Salmonella spp., the ISO 6579:2020 [ 33 ] method was used. The species confirmation of the isolates was performed via the application of simplex PCR for the search of the bcfC gene according to the described protocol [ 34 ]. On Salmonella isolates phenotypic serotyping was conducted by slide agglutination and phase inversion (ISO 6579:2020) [ 33 ].…”