The Customer: A manufacturer of powdered infant formula.
The Challenge: The company discovered that its finished product was consistently contaminated with low levels of Enterobacter sakazakii (Cronobacter).Recognizing that bacteria in powder could grow rapidly in reconstituted milk, the manufacturer wanted to understand how its product was becoming contaminated.
The Solution: Accurate, detailed microbial information can be a manufacturer’s best tool for combating unwanted organisms. So the infant formula manufacturer’s Quality Control (QC) personnel undertook a detailed analysis of all operations. They were able to isolate the pathogen frequently in products from two factories and infrequently in products from a third.
A survey of raw materials and the environment at each site yielded several hundred samples of the unwanted bacteria. The QC team performed some preliminary screening using biochemical methods, but those data were not helpful in tracking the contamination. The team then turned to the RiboPrinter® Microbial Characterization System from DuPont.
The RiboPrinter® System was able to discriminate among many of the contaminant strains below the species level, which allowed the company to learn how the contamination was being spread throughout the factories. For example, 30 strains of the organism found in one factory clustered into 8 sets of similar patterns (two of which are shown below). By examining this level of characterization and identification, the investigators could see which strains were confined to a single site and which were common to all three factories.
Important trends also became evident. The use of portable vacuum cleaners to reduce dust and powder contamination presented a cross-contamination hazard, as the vacuum cleaners were moved from one area of the factory to another. Also, personnel movement appeared to be a factor in the transfer of some strains. Finally, investigators for this infant formula manufacturer determined that “resident” florae of a particular type of the bacteria were able to evade standard cleaning and sanitation regimes. The risk of this source of contamination was considered significant.
The company changed its cleaning practices to address these issues. It has built the information into the QC database and regularly monitors the contamination patterns of the organism. The QC team recognizes that changes in the subspecies florae may indicate a problem in process or hygiene practices; the team can then quickly direct cleaning crews and engineers to the area of concern.
The RiboPrinter® System was invaluable in helping this business quickly and definitively address the source and route of contamination throughout its complex manufacturing operation.
