How it Works: Bacterial Culturing for Faster Microbe Detection

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Problem: When it comes to bacterial culturing, modern laboratories have little choice but to wait days for definitive proof that bacteria are alive and pose a health threat. Labs typically wait 18 to 24 hours for E.coli and Listeria cultures to grow, 48 hours for Yersinia pestis (Bubonic Plague) and 72 hours for Group B Streptococcus, just to name a few. PCR methods seem to solve this slow growth problem, but the tests are expensive, require specialized equipment and training, and do not distinguish between live and dead microbes. For more accurate results, laboratories culture samples and run their operations on a microbe’s timetable, no matter how serious that wait may be for a patient or public health.

In clinical settings, these long wait times force physicians to treat empirically even in the face of active infection. In the pharmaceutical, cosmetics, food and beverage industries, extensive wait times for quality control results can delay the identification of contaminated or spoiled product batches and increase public health risks. Additionally, the public is put at risk when people are exposed to waterborne pathogens days before positive results for bacteria such as E.coli and Staphylococcus aureus prompt beach closures.

Faced with the speed of DNA sequencing and the growing convenience of single-use diagnostics, today’s laboratories experience increasing demand to return results faster. Unfortunately, microbes cannot be forced to grow any faster than their current speeds.

After five minutes on the NanoLogix staining plate (green dish), bacterial micro colonies grown on the membrane are visible to the naked eye.

Solution: Today, new testing methods are making microorganisms visible sooner. Developed by NanoLogix, these methods are known to cut detection and identification times by at least 4 times. Instead of simply using a nutrient agar to culture colonies, a permeable, polymeric membrane can be sandwiched in between two agar layers. This extremely thin, clear membrane allows tiny microorganisms to grow and then be transported to a staining plate, after a third to a quarter of conventional incubation time has passed. Ten to fifteen minutes on a staining agar makes previously invisible micro colonies visible for detection. To further identify target bacteria, steps include a filtration process based on an immuno-enzymological method that uses HRPantibody conjugates to remove unwanted microbes. This target identification process increases sensitivity to as low as one cell.

By concentrating on this inexpensive, permeable membrane method, NanoLogix has developed a suite of products to detect and identify hazardous bacteria and assorted yeasts quickly, accurately and cost effectively. The company’s several technologies speed detection of E.coli. and Salmonella by four times or more, Group B Streptococcus by at least twelve times, and Yersinia pestis by at least two times, to name just a few.

At the University of Texas Health Science Center, NanoLogix’s BioNanoFilter technology is undergoing a 300-patient trial to detect and identify Group B Streptococcus (GBS) in pregnant women. Meanwhile, NanoLogix is working with the U.S. Environmental Protection Agency (EPA) to develop a rapid test to detect E coli. and Cryptosporidium in U.S. waterways, based on its BioNanoChannel technology.

The best materials for these membranes are non-permeable to cell structures, non-toxic, hydrophilic and non-fluorescent. Additionally, the membrane should be capable of working with organic and non-organic molecules and proteins.

For the most accurate results and to prove there is a health threat, labs must wait for bacteria to grow. NanoLogix cuts those wait times by helping labs see results sooner and meet the growing demand for faster, more accurate test results with a simpler and less expensive method than what is currently on the market.

For more information, visit www.nanologix.com

Categories: How it Works

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Published In

Confident? Magazine Issue Cover
Confident?

Published: February 1, 2011

Cover Story

Confident?

Our third annual confidence survey reveals that survey participants—ranging from technicians to corporate management—believe their research organizations will be just slightly better off financially than they were a year ago and that business conditions in their market sectors will somewhat improve to support or attract significant research investments.