Viable But Non-Culturable (VBNC) Bacteria: Threats and Solutions
Viable but non-culturable (VBNC) bacteria are exactly what they sound like — bacteria that are viable and capable of causing infections, but that defy our conventional culturing techniques, posing significant challenges for researchers and public health professionals.
What are VBNC Bacteria?
VBNC refers to a state in which bacteria maintain metabolic activity and viability but are unable to be cultured using standard laboratory techniques. Under stressful conditions (i.e. in response to adverse environmental conditions), many species of bacteria enter a “starvation mode” in which they have very low metabolic activity and do not divide, yet retain their viability and express their virulence. Entering this state allows the bacteria to conserve energy and resources, extending their survival in environments that may not support their normal life cycle. Once conditions become more favorable, they can often “resuscitate” and revert to their active, replicative state. Various environmental factors can induce the transition of bacteria into the VBNC state, such as temperature fluctuations, nutrient deprivation, exposure to biocides, and other stressors.
Since VBNC bacteria do not divide, they cannot be grown using conventional culture media. Culturing is a laboratory technique used to grow and propagate microorganisms, such as bacteria, fungi, and viruses, in a controlled environment. During the culturing process, a sample containing microorganisms is introduced onto a growth medium, such as agar, and placed in an incubator with conditions favorable for growth, ultimately forming visible colonies. However, if bacteria are in the VBNC state, they will not divide and thus, go undetected with traditional culturing methods.
Public Health Implications
The existence of VBNC pathogens adds a layer of complexity to our understanding and management of infectious diseases. If these pathogens can maintain viability without being detected by routine laboratory tests, it raises concerns about our ability to accurately assess the prevalence of certain infections. This has significant implications for public health surveillance, outbreak investigation, and the development of effective treatment strategies.
VBNC bacteria can go undetected using conventional culture methods, leading to an underestimation of the true prevalence of certain infections. This can result in a skewed understanding of disease burden and hinder public health efforts to allocate resources for prevention, treatment, and control. Furthermore, timely and accurate identification of the causative agent is crucial for effective outbreak control. The presence of VBNC bacteria may complicate these investigations, potentially delaying response measures.
VBNC pathogens have been particularly studied in the context of waterborne diseases. Pathogens like Vibrio cholerae, responsible for cholera, and Escherichia coli (E. coli) have been found to enter the VBNC state in response to changes in environmental conditions, particularly in aquatic environments. This poses challenges for water quality monitoring and the prevention of waterborne outbreaks.
The Need for Advanced Detection Techniques
To address the challenges posed by detecting VBNC pathogens, advanced detection techniques, such as molecular methods (PCR, qPCR), immunological assays, and metagenomics, are increasingly being employed. These techniques offer more direct and sensitive approaches to identifying the presence of pathogens, providing a more accurate assessment of water quality and disease burden.
The KRAKEN takes a non-culture-based approach, bypassing the need for traditional cultivation methods. Unlike conventional techniques that may struggle to detect VBNC pathogens, the KRAKEN harnesses the power of quantitative real-time PCR to detect genetic material, rather than the presence of colonies, to accurately detect and quantify microorganisms. By using chemical and mechanical methods to concentrate samples, the KRAKEN overcomes the challenges posed by VBNC pathogens, as it does not require bacteria to be in a culturable state. Furthermore, the KRAKEN goes beyond qualitative analysis; it incorporates accurate quantification methods that facilitate the identification of even low levels of VBNC pathogens.
The ability to detect VBNC pathogens is crucial for public health surveillance, outbreak investigation, and the development of effective strategies for preventing the spread of infectious diseases. KRAKEN's qPCR-based approach ensures that viable pathogens do not go undetected, particularly in scenarios where traditional methods may fail to capture the full spectrum of microbial threats, providing a more comprehensive picture of the potential risks to public health.
Conclusion
Viable but non-culturable (VBNC) bacteria pose intricate challenges to our conventional methods of pathogen detection, requiring innovative solutions for accurate assessment and effective management of infectious diseases. The elusive nature of VBNC pathogens complicates public health surveillance, outbreak investigations, and resource allocation, emphasizing the need for advanced detection techniques. However, the KRAKEN device stands as a beacon of progress in overcoming these challenges. By accurately identifying and quantifying genetic material from viable pathogens, including those in the VBNC state, KRAKEN ensures that our understanding of disease prevalence is comprehensive and nuanced. In a landscape where swift responses are paramount, KRAKEN's capabilities empower public health professionals to proactively develop strategies for preventing the spread of infectious diseases, marking a significant leap forward in the field of pathogen detection and public health preparedness.
About Kraken Sense
Kraken Sense develops all-in-one pathogen detection solutions to accelerate time to results by replacing lab testing with a single field-deployable device. Our proprietary device, the KRAKEN, has the ability to detect bacteria and viruses down to 1 copy/mL. It has already been applied for epidemiology detection in wastewater and microbial contamination testing in food processing, among many other applications. Our team of highly-skilled Microbiologists and Engineers tailor the system to fit individual project needs. To stay updated with our latest articles and product launches, follow us on LinkedIn, Twitter, and Instagram, or sign up for our email newsletter. Discover the potential of continuous, autonomous pathogen testing by speaking to our team.