Related Experiment Video
Updated: Jul 7, 2026
Detection of Live Escherichia coli O157:H7 Cells by PMA-qPCR
Published on: February 1, 2014
Tracing of Enterobacter sakazakii isolates in infant milk formula processing by BOX-PCR genotyping
I Proudy1, D Bouglé, R Leclercq
1Service de Microbiologie, EA 2128 Interactions Hôte et Micro-organismes des Epithéliums, Centre Hospitalier Universitaire (CHU), Université de Caen Basse-Normandie, Avenue Côte de Nacre, Caen cedex, France.
Insights
The processing environment, not raw materials, was the primary source of Enterobacter sakazakii contamination in powder infant formulae (PIF). BOX-polymerase chain reaction (PCR) effectively identified contamination sources and guided control measures.
Area of Science:
- Food safety
- Microbiology
- Public health
Background:
- Enterobacter sakazakii is a food-borne pathogen causing severe neonatal infections.
- Contaminated powder infant formulae (PIF) are a known infection route.
- Understanding E. sakazakii dissemination in PIF factories is crucial for prevention.
Purpose of the Study:
- To monitor E. sakazakii in a PIF processing environment.
- To identify potential dissemination routes of the pathogen.
- To assess the effectiveness of control measures.
Main Methods:
- Utilized BOX-polymerase chain reaction (PCR) for E. sakazakii fingerprinting and strain typing.
- Collected and analyzed 200 E. sakazakii isolates from the PIF processing environment.
- Investigated clonal persistence and identified contamination points.
Main Results:
- 70% of E. sakazakii isolates shared the same fingerprint, indicating persistent resident strains.
- BOX-PCR successfully detected PIF contamination originating from dry-blending ingredients.
- The processing environment was identified as the major contamination source for PIF.
Conclusions:
- Environmental contamination is the primary cause of PIF contamination.
- Routine BOX-PCR genotyping aids in real-time microbial dissemination tracking.
- Effective control measures can be implemented to reduce E. sakazakii risk in PIF.
Aims:
Enterobacter sakazakii is an emerging food-borne pathogen that can cause rare but severe neonatal meningitis, bacteraemia and necrotizing enterocolitis. Contaminated powder infant formulae (PIF) have been identified as one of various infection routes. In this study, E. sakazakii was monitored in the processing environment of a PIF factory to identify possible dissemination routes.
Methods And Results:
The BOX-polymerase chain reaction (PCR), a fingerprinting technique which targets the repetitive BOX sequences, was used in routine to identify points of contamination and investigate clonal persistence. Two hundred E. sakazakii isolates were collected and typed. Most (70%) showed the same fingerprint that revealed the persistence of resident E. sakazakii strains in the processing environment. This method allowed to detect contamination of some PIF by dry-blending ingredients.
Conclusions:
Environment was the major cause for contamination of PIF and facilities. Some raw materials delivered as powder were also implicated.
Significance And Impact Of The Study:
Routine BOX-PCR genotyping was very useful to trace and investigate in real-time dissemination of micro-organisms in the PIF plant and to implement a series of additional control measures to reduce the risk of final product contamination by E. sakazakii.
