Controlling Cronobacter: A Pathogen of Concern in Dry Environments and Low-Moisture Foods

Cronobacter is a ubiquitous bacterium found naturally within the environment that can also survive in low-moisture foods.

Low-moisture foods are those with a low water activity (aw) < 0.85, and include dried milk powder, herbal teas, and starches. The ability of Cronobacter to survive in these foods makes it a pathogen of concern in dry food production.

Although Cronobacter-related illnesses are rare within the general population, Cronobacter sakazakii (1) has been associated with a number of foodborne outbreaks and can cause serious blood infections in very young babies (or neonates) leading to septicemia, meningitis, and even death.

The U.S. Food and Drug Administration’s (FDA’s) Coordinated Outbreak Response and Evaluation (CORE) Network, along with the Centers for Disease Control and Prevention (CDC) and state and local partners, recently investigated infant formula products. To date, four hospitalizations and two deaths have been associated with this investigation, where Cronobacter infection may have contributed to the cause of death for both patients (2,3).

Cronobacter sakazakii: Key Information

Cronobacter sakazakii
Source: FDA (1)

Characteristics: Gram-negative, non-spore forming bacteria found in the environment.

Areas of High Concern: Can survive in dry environments and low-moisture foods, e.g., powdered infant formula, for long periods.

Affected Population: Neonates (babies < 2 months old), infants, elderly, and the immunocompromised. 10 - 80% mortality rate.

Transmission: Most Cronobacter infections are caused by consumption of contaminated food.

Common Symptoms: Jaundice, temperature changes, grunting breath, and seizures. Babies are most likely to develop meningitis.

Infective dose: Not determined. Symptoms occur in infants within a few days or weeks, but onset in adults has not been determined.

Cronobacter: Control

The following are some of the effective measures used to mitigate Cronobacter-related risks in powdered infant formula or similar high-care products:

(a) Ensuring proper process controls – Although Cronobacter survival in low-moisture products for up to 2 years has been reported, the pathogen is easily destroyed by pasteurization, sterilization, or equivalent thermal treatment of ingredients and products; therefore, such critical process steps must be scientifically or technically validated to ensure efficacy. Additionally, any ingredients added after the “kill step” must be properly processed and handled in a sanitary manner to avoid final product contamination.

(b) Having adequate high-care product preparation guidelines for consumers – Manufacturers should consider the provision of advice to those preparing infant formula for babies younger than 2 months old, those born prematurely, or those with a weakened immune system to minimize the risk of Cronobacter introduction and survival, e.g., by providing extra CDC advisory precautions, FDA guidance on preparing and storing infant formula products safely, and/or following WHO guidelines.

(c) Establishing risk-based environmental monitoring and control programs – Low-moisture food production sites are recommended by food safety and hygiene experts (9) to routinely test food contact and non-food contact surfaces for an appropriate indicator organism, i.e., Enterobacteriaceae. A positive swab may be indicative of the presence of Cronobacter. This can then be confirmed through specific pathogen testing. Environmental monitoring may help identify Cronobacter contamination hotspots and allow targeted control through appropriate sanitation practices, e.g., hygienic zoning, sanitation protocols, hygienic/sanitary equipment design, etc.

(d) Controlling post-processing contamination incidents in dry facilities – Low-moisture food production sites should avoid, reduce, or control the amount of water used in their facility. Water allows bacteria to grow and spread. Consequently, the use of water for sanitation can play a significant role in increasing microbial risk. Appropriate selection and use of dry sanitation tools (4) and methods is essential to ensure that sanitation is effective and minimizes the risk of microbial growth and spread.

(e) Developing a robust sanitation and tool management program – Remco and Vikan suggest developing an integrated sanitation approach aimed at minimizing the food safety risk to all food products. This integrated approach can include any or all of the following:

• Implementation of a risk-based, 5S-centered hygienic zoning program (5)
• Selection of high-quality, durable, color-coded tools
• Use of hygienically designed tools (6) for high-risk/high-care zones, product surfaces, etc.
• Effective tool decontamination before and after use (7,8)
• Proper tool storage, care, and replacement procedures (7,8)

For close to 125 years, Vikan has been providing our end-users working in dry production facilities and other hygiene-sensitive sites with high-quality sanitation and food handling tools, innovative solutions, and high-quality services. More information about our products and services is available at our website. To schedule a complimentary site survey, please contact us.

References:
1. Bad Bug Book (Second Edition) | FDA
2. Home | Cronobacter | CDC
3. FDA Investigation of Cronobacter Infections: Powdered Infant Formula (February 2022) | FDA
4. Dry Snacks Ready-To-Eat Processing - Remco (remcoproducts.com)
5. https://viewer.ipaper.io/vikan/white-papers/5s-in-the-food-industry/5sfoodindustryen/
6. http://viewer.ipaper.io/vikan/food-safety-information/ultra-hygiene/ultra-hygiene-advertorial-en-300/
7. How to Keep Cleaning Tools from Becoming Vectors of Contamination (vikan.com)
8. Cleaning-Tool-Maintenance-WhitePaper-EN-300 (ipaper.io)
9. Bourdichon, F., Betts, R., Dufour, C., Fanning, S., Farber, J., McClure, P., & Winkler, A. (2021). Processing environment monitoring in low moisture food production facilities: Are we looking for the right microorganisms? International Journal of Food Microbiology, 356, 109351.