Vendart Diagnostics tells Food & Beverage Industry News how its mobile flow cytometer, CytoQuant, works to ensure your facility follows food-grade hygiene practices.
The presence of bacteria in food and beverage manufacturing facilities can affect product shelf life and quality, while pathogens can lead to foodborne illness. Cleaning and disinfection is therefore paramount to securing food safety and protecting both your reputation and your business. But cracking down on something we can’t see isn’t always easy and straightforward.
While visual inspection is a good first step, it isn‘t enough. Traditional microbiological methods often don’t allow for preventive control and preoperational actions as lab results take days. ATP tests, while simple and fast, quantify biological residues, which are not a meaningful proxy for disinfection efficacy. Each one of these methods comes with considerable limitations. Yet you are expected to make informed decisions, fast.
CytoQuant is a mobile flow cytometer that enables the immediate, onsite verification of cleaning and disinfection procedures in food production facilities or other areas where hygiene is crucial by directly quantifying bacteria and particles on surfaces.
Some of the features and benefits of CytoQuant include:
- Direct quantification of bacteria and residue particles enable proper verification of cleaning and disinfection procedures;
- Results in 30 seconds;
- Measurements are not influenced by disinfectants or temperature, reducing result variability;
- Simple test procedure does not require a lab or special training; and
- Simple connectivity allows you to save, export and document test results with ease.
How does CytoQuant work?
After swabbing a surface, the device draws the sample from the swab kit into the flow system, channelling it into a small microfluidic flow cell (CountCell) which is the heart of the technology. The CountCell consists of a flow channel and an array of electrodes that perform the measurements. During a measurement, the sample containing the bacteria and particles flows through the flow channel.
Imagine a flow channel with an electrode positioned both at the top and the bottom of the channel. Between the two electrodes, electrical currents are flowing at low and high frequencies. An object passing between the electrodes will introduce a change to the current. It is this flow change that the technology is calibrated to detect. Particles can be either conductive or non-conductive.
Bacteria have unique electrical properties due to their intact membrane and cytoplasm. They have a non-conductive shell and core. The isolating quality of the cell membrane prevents the electrical field from penetrating it at low frequencies (similar to non-conductive particles). At higher frequencies cells are similar to conductive particles. This specific behaviour acts as a fingerprint allowing CytoQuant to distinguish between bacteria and other particles. The results – accurate, precise counts of bacteria and particles that you can use to verify your cleaning procedure.
What are we really measuring?
How do intact cells and particles relate to common, known parameters?
CytoQuant provides precise counts of intact cells and particles. Intact cells are defined as cells with an intact cell wall, irrespective of their state (such as stressed, or viable but not culturable) or required growth conditions (aerobic or anaerobic, pH, nutrition, salt concentration, temperature, lag-time, incubation time, etc.). Because no solid or liquid media can cover this full range, and because only about 1 per cent of existing bacteria are culturable, intact cell counts and plate counts are two very different parameters.
CytoQuant additionally classifies any objects that are not bacteria and pass through the microfluidic flow cell as residue particles. Particle counts are a direct indication of cleanliness.
How reliable are CytoQuant intact cell count results?
The accuracy of CytoQuant measurements has been the subject of a large number of studies. In the latest, described below, Romer Labs partnered with the Karl Landsteiner University of Health Sciences in Austria and compared the intact cell counts of the CytoQuant mobile flow cytometer with counts from a fluorescence microscope, a fluorescence flow cytometer and those from aerobic plates (TSA: tryptic soy agar).
Not only were counts from CytoQuant closest to those of the reference microscope method (Figure 1), CytoQuant also had the lowest relative average standard deviations of all methods. As expected, TSA plates returned the lowest bacteria counts as not all colonies emerge from a single cell and not all cells eventually multiply and form colonies. The fluorescence flow cytometer had significantly lower bacteria counts than CytoQuant and the reference microscope method.
Why should QC managers make the switch to CytoQuant?
CytoQuant is currently the only solution on the market able to provide a clear picture about the microbial condition of production surfaces in real time.
Traditional microbiological methods often don’t allow for preventive control and pre-operational actions because lab results for plate count testing takes days. ATP tests, while simple and fast, quantify biological residues which are not an indication of disinfection efficacy. Each of these methods comes with considerable limitations, yet the user is expected to make informed decisions, fast.