Comparison of methods for the microbiological identification and typing of Cronobacter species in infant formula

Area of Science:

• Food safety and microbiology
• Microbial identification techniques
• Public health and infant nutrition

Background:

• Cronobacter species are emerging opportunistic foodborne pathogens linked to severe infant illnesses like meningitis and necrotizing enterocolitis.
• Powdered infant formula (PIF) is identified as a primary vehicle for Cronobacter contamination, posing a significant risk to vulnerable populations.
• Accurate and efficient identification methods are crucial for controlling Cronobacter in food production environments.

Purpose of the Study:

• To evaluate and compare different methods for identifying and typing Cronobacter species.
• To determine the most effective technique for detecting Cronobacter contamination in powdered infant formula (PIF) and its processing environments.
• To assess the potential of Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for tracing Cronobacter dissemination in the food production chain.

Main Methods:

• Biochemical profiling using the API 20E system.
• Protein profiling via Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).
• Genotypic profiling using ribotyping.

Main Results:

• MALDI-TOF MS and biochemical identification demonstrated higher accuracy than ribotype analysis for Cronobacter species.
• MALDI-TOF MS typing and ribotype analysis offered superior discriminatory power compared to biochemical phenotyping.
• Cronobacter strains were analyzed from various geographic locations and PIF processing environments.

Conclusions:

• MALDI-TOF MS is a rapid, reliable, and highly discriminatory method for identifying Cronobacter species in PIF.
• This technique holds significant potential for tracing the spread of Cronobacter contamination throughout the production process.
• Effective identification methods are key to enhancing food safety and preventing infant infections caused by Cronobacter.