Cherney Blog: Inside The Petridish

Your blog resource for education, experience, and a good read!

Cherney Blog: Inside The Petridish

Your blog resource for education, experience, and a good read!

Let's Talk About It: Coliform & Enterobacteriaceae!

Posted by Lauren Ellie on Feb 9, 2021 9:17:05 AM
Lauren Ellie
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Did you hear about the famous microbiologist who visited 30 different countries and spoke 6 languages?

He was a man of many cultures!
 
And speaking of many cultures, let’s talk about the wide world of indicator organisms!
 
 
An indicator organism is a certain bacteria or group of bacteria that are not necessarily harmful themselves but can indicate that the conditions are prime for a harmful pathogen to be present. Indicator organism(s) can be a broad group of bacteria (E.g. Enterobacteriaceae) or it could be a specific species of bacteria (E.g. Staphylococcus epidermidis) depending on what pathogen you’re concerned with. Testing for indicator organisms can also be used to assess efficacy of cleaning and sanitation programs within your plant or during troubleshooting product issues to quantify spoilage organisms present.
Indicators
 

Enterobacteriaceae

 
Enterobacteriaceae is used mainly as an indicator organism for the potential presence of Salmonella and other bacteria in the EB family. Testing within the industry has shifted from primarily using coliform as an indicator organism to using Enterobacteriaceae as an indicator.

GreenLg Purp  But why?     PurpPink

It’s primarily due to the fact that the EB family is much larger and encompasses many potential pathogens, including Salmonella and coliforms. Just testing for coliforms provides a more specific view and can still be a useful tool as an indicator for E coli, fecal contamination and/or sanitization issues.
About the EB family: The EB family can be discussed by splitting into three primary sections based on their ability to ferment Lactose.
 
  • Those that typically do not ferment lactose
    • (Includes: Salmonella and Shigella, along with many other bacteria.)
  • Those that can ferment Lactose at a slow rate
  • And those that have the ability to rapidly ferment Lactose
    • (Includes: Coliforms such as Escherichia coli or E.coli)
These are just some of the well-known examples from each section, the EB family is extremely vast and is comprised of over 100 different organisms.
 
Growth conditions: Enterobacteriaceae grow at temperatures from 28°F to 122°F. They grow in a wide pH range of 4.4-9.0.
 
EB in your environment: EB is typically used during environmental testing as an indicator. It is often tested using a plate count method test. And many of our customers use this data to track and trend results by location over time. They often set alert and action levels so they are aware when the level of organisms has increased, perhaps due to lack in sanitization or a change in production.
 

Coliforms

 
Coliforms are a part of the Enterobacteriaceae (EB) family and are represented by four genera namely: Citrobacter, Enterobacter, Escherichia, Klebsiella. Coliform bacteria are organisms that are present in the feces of warm-blooded animals and humans but can also be found in the environment, in water, in soil, and on vegetation. Coliforms can be used as an indicator organism for the potential presence of fecal contamination and/or the potential for pathogenic E.coli in products or the environment.
 
Growth conditions: Coliforms grow at temperatures from 28°F to 122°F. In foods, growth is poor or very slow at 41°F or lower. They grow in a pH range of 4.4-9.0.
 
Coliform in your environment: Coliform, similar to EB, is often used during environmental testing as an indicator. It can be a good indication of how effective your sanitization program is. And many of our customers use this data to track and trend results by location over time. This may be an indication to take a look at sanitization procedures or enhance testing in those areas/products that have come into contact with those areas to be sure there isn’t E.coli present.
 
 
Interested in learning more?
Check out our other Blogs, or check out our Webinars! They are loaded with interesting information.
 

Topics: Continuing Education, Cherney Micro, Food Safety, Environmental Monitoring, Microbiology, Food Safety Modernization Act (FSMA), Service to the Customer, Technical Services