Molecular Characterization ofSalmonellaSerovars Anatum and Ealing Associated with Two Historical Outbreaks, Linked to Contaminated Powdered Infant Formula.
Powdered infant formula (PIF) is not intended to be produced as a sterile product unless explicitly stated and on occasion may become contaminated during production with pathogens such asSalmonella enterica. This retrospective study focused on two historically reported salmonellosis outbreaks associated with PIF from the United Kingdom and France, in 1985 and 1996/1997. In this paper, the molecular characterization of the two outbreaks associatedSalmonellaserovars Anatum and Ealing is reported. Initially the isolates were analyzed using pulsed-field gel electrophoresis (PFGE), which revealed the clonal nature of the two outbreaks. Following from this two representative isolates, one from each serovar was selected for whole genome sequencing (WGS), wherein analysis focused on theSalmonellapathogenicity islands. Furthermore, the ability of these isolates to survive the host intercellular environment was determined using anex vivogentamicin protection assay. Results suggest a high level of genetic diversity that may have contributed to survival and virulence of isolates from these outbreaks.
UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin Dublin, Ireland.
Lynda
L
Gunn
UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin Dublin, Ireland.
Sarah
S
Finn
UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin Dublin, Ireland.
Daniel
D
Hurley
UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College DublinDublin, Ireland; Key Laboratory of Food Safety Risk Assessment, Ministry of Health, China National Center for Food Safety Risk AssessmentBeijing, China.
Li
L
Bai
UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin Dublin, Ireland.
Ellen
E
Wall
UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin Dublin, Ireland.
Carol
C
Iversen
Health Protection Agency London, UK.
John E
JE
Threlfall
UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College DublinDublin, Ireland; Key Laboratory of Food Safety Risk Assessment, Ministry of Health, China National Center for Food Safety Risk AssessmentBeijing, China; Institute for Global Food Security, Queen's University BelfastBelfast, UK.
Séamus
S
Fanning
PFGE; Salmonella pathogenicity islands; core genome; infection model; whole genome sequencing