Open AccessWhole-genome sequencing of the rare Salmonella enterica serovar Anfo isolated from food handlers
Author(s) -
Sophie Octavia,
Siti Zulaina,
Swee Kai Seet,
Wee Siong Tien,
Minn Thu,
Peng Lim Ooi,
Lin Cui,
Raymond TzerPin Lin
Publication year - 2019
Publication title -
journal of medical microbiology/journal of medical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 117
eISSN - 1473-5644
pISSN - 0022-2615
DOI - 10.1099/jmm.0.000934
Subject(s) - serotype , salmonella , salmonella enterica , biology , food poisoning , microbiology and biotechnology , virulence , whole genome sequencing , genome , antibiotic resistance , gene , virology , bacteria , antibiotics , genetics
Field investigations were conducted after a small cluster of food poisoning involving six cases was reported. While no stool samples were available from the cases for microbiological testing, Salmonella species was found to be present in the stools of food handlers with gastroenteritis symptoms. Four Salmonella isolates recovered from the food handlers were retrospectively investigated at the genome level using whole-genome sequencing (WGS). WGS showed that S. Anfo (antigenic formulae 39:y:1,2), a rarely isolated serovar, caused infections in the food handlers. S. Anfo analysed in this study contained virulence factors required for causing disease. They did not contain any antibiotic resistance genes or plasmid. The epidemiologically related isolates differed to each other by a maximum of one single nucleotide polymorphism. WGS was useful in identifying rare Salmonella serovars and it is potentially more cost-effective than traditional serotyping methods. It can also confidently group epidemiologically related isolates belonging to S. Anfo.