Molecular epidemiology of the endemic multiresistance plasmid pSI54/04 of Salmonella Infantis in broiler and human population in Hungary. (May 2018)

• Record Type: Journal Article
• Authors: Szmolka, Ama; Szabó, Móni; Kiss, János; Pászti, Judit; Adrián, Erzsébet; Olasz, Ferenc; Nagy, Béla
• Is Part Of: Food microbiology. Volume 71(2018)
• Page Start: 25
• Page End: 31
• Publication Date: 2018-05
• Subjects: S. Infantis -- Plasmid -- Broilers -- PFGE clone -- Molecular typing; Food Microbiology -- Periodicals; Aliments -- Microbiologie -- Périodiques; Food -- Microbiology; Periodicals; Food -- Microbiology -- Periodicals; Food contamination -- Periodicals; 664.001579
• DOI: 10.1016/j.fm.2017.03.011
• Languages: English
• ISSNs: 0740-0020

Abstract

Abstract: Salmonella Infantis (SI) became endemic in Hungary where the PFGE cluster B, characterized by a large multiresistance (MDR) plasmid emerged among broilers leading to an increased occurrence in humans. We hypothesized that this plasmid (pSI54/04) assisted dissemination of SI. Indeed, Nal-Sul-Tet phenotypes carrying pSI54/04 occurred increasingly between 2011 and 2013 among SI isolates from broilers and humans. Characterization of pSI54/04 based on genome sequence data of the MDR strain SI54/04 indicated a size of ∼277 kb and a high sequence similarity with the megaplasmid pESI of SI predominant in Israel. Molecular characterization of 78 representative broiler and human isolates detected the prototype plasmid pSI54/04 and its variants together with novel plasmid associations within the emerging cluster B. To test in vitro and in vivo pathogenicity of pSI54/04 we produced plasmidic transconjugant of the plasmid-free pre-emergent strain SI69/94. This parental strain and its transconjugant have been tested on chicken embryo fibroblasts (CEFs) and in orally infected day old chicks. The uptake of pSI54/04 did not increase the pathogenicity of the strain SI69/94 in these systems. Thus, dissemination of SI in poultry could be assisted by antimicrobial resistance rather than by virulence modules of the endemic plasmid pSI54/04 in Hungary. Highlights: Plasmid pSI54/04 contributes to multiresistance in recent isolates of S. Infantis. pSI54/04 and plasmid pESI of S. Infantis in Israel share high sequence similarity. Variants of pSI54/04 differ in antimicrobial- and heavy metal resistance regions. Transfer of pSI54/04 did not increase pathogenic potential of S. Infantis.