Identification of genes that contribute to fitness of African and Global clades of Salmonella Enteritidis during infection of macrophages

Yee Fong, Wai, Canals, Rocío, Predeus, Alex, Perez-Sepulveda, Blanca and Feasey, Nicholas ORCID: https://orcid.org/0000-0003-4041-1405 (2020) 'Identification of genes that contribute to fitness of African and Global clades of Salmonella Enteritidis during infection of macrophages'. Access Microbiology, Vol 2, Issue 7A.

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Abstract

Non-typhoidal Salmonella (NTS) usually cause gastroenteritis in humans, but in recent years NTS have begun to cause epidemics of bloodstream infections in Africa. Salmonella Enteritidis is the second most common serovar associated with this invasive form of NTS disease (iNTS) in Africa. To establish a systemic infection, Salmonella must survive and replicate within host cells, with macrophages being a primary target. Genomic characterisation of S. Enteritidis isolates from human bloodstream has identified two new clades that are unique to Africa and distinct from the Global Epidemic clade. The African S. Enteritidis clades exhibit genomic degradation, and possess a distinct prophage repertoire and are multi-drug resistant. However, little is known about the virulence factors that allow African S. Enteritidis to cause systemic infection in susceptible hosts. We screened libraries of random insertion mutants of African and Global S. Enteritidis by transposon insertion sequencing (TIS), and identified about 280 genes belonging to each clade that contribute to bacterial survival and replication in murine macrophages. The genes were associated with 5 pathogenicity-islands, or encoded the global regulators PhoPQ and OmpR-EnvZ. Experiments are ongoing to investigate the role in intra-macrophage replication of genes that are uniquely identified in African Salmonella. It is hoped that our findings will contribute to a greater understanding of African Salmonella infection biology, and that some of the virulence-associated genes could be potential targets for novel therapeutics.

Item Type:	Article
Subjects:	WC Communicable Diseases > Infection. Bacterial Infections > Enteric Infections > WC 269 Salmonella infections WH Hemic and Lymphatic Systems > Lymphatic System > WH 650 Reticuloendothelial system WI Digestive System > WI 100 General works
Faculty: Department:	Clinical Sciences & International Health > Clinical Sciences Department Clinical Sciences & International Health > International Public Health Department
Digital Object Identifer (DOI):	https://doi.org/10.1099/acmi.ac2020.po0739
Depositing User:	Julie Franco
Date Deposited:	17 Sep 2020 16:47
Last Modified:	23 Sep 2020 09:55
URI:	https://archive.lstmed.ac.uk/id/eprint/15614

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