Evaluation and implementation of a membrane filter method for Cronobacter detection in drinking water

Area of Science:

• Microbiology
• Water Quality Analysis
• Food Safety

Background:

• Cronobacter spp. are potential opportunistic pathogens in drinking water.
• Accurate detection methods are crucial for public health protection.
• Existing methods may have limitations in sensitivity or specificity.

Purpose of the Study:

• To evaluate the membrane filter (MF) method for detecting Cronobacter spp. in drinking water.
• To assess the MF method's performance using pure cultures and spiked samples.
• To compare Cronobacter contamination levels in different types of water supplies.

Main Methods:

• Testing the MF method with pure strains of Cronobacter and non-Cronobacter species.
• Analyzing drinking water samples spiked with chlorinated Cronobacter sakazakii.
• Applying the MF method to screen municipal water supplies on premises (MWSP) and small community water supplies on premises (SCWSP).
• Investigating the use of total coliforms as an indicator for Cronobacter contamination.

Main Results:

• The MF method demonstrated 100% sensitivity and specificity for pure strains.
• Recovery of spiked Cronobacter sakazakii cells was 82.8 ± 10.4%.
• Cronobacter spp. isolation rate was significantly higher in SCWSP (31/114) than MWSP (1/131).
• Total coliforms showed a 96% correct positive rate as an indicator for Cronobacter contamination.

Conclusions:

• The MF method is a reliable tool for both qualitative and quantitative analysis of Cronobacter spp. in drinking water.
• SCWSP pose a higher risk for Cronobacter contamination compared to MWSP.
• Total coliforms can serve as a useful indicator for monitoring Cronobacter contamination in drinking water.