It’s Time to Incorporate Klebsiella variicola into Your Bloodstream Infection Testing

Klebsiella variicola is an emerging pathogen that can be highly invasive and, in some cases, multidrug-resistant—leading to increased mortality among critical patients.

While the discovery of new pathogens might be interesting for epidemiologists, it remains a constant challenge for the clinical lab community. Developing new tests or waiting for regulatory clearance of commercial tests that include the new target requires a significant amount of time and budget.

In the realm of bloodstream infections, one of the latest pathogens getting attention is the gram-negative bacterium Klebsiella variicola. First identified in 2004, this microbe was initially seen in plants, where it appeared to cause little harm. Since then, K. variicola has emerged as a human health threat. At least one study found that this pathogen leads to higher mortality rates than other close relatives, such as Klebsiella pneumoniae. Although K. variicola is not consistently more resistant than K. pneumoniae, emerging evidence shows it can harbor multidrug resistance, including carbapenemase genes. Surveillance studies report that while most isolates remain highly susceptible to carbapenems and aminoglycosides, up to 12% exhibit extended-spectrum beta-lactamase production and multidrug resistance, and concerning trends like colistin resistance are appearing. In one recent study, all strains analyzed were resistant to multiple classes of antibiotics, and some had other heightened virulence factors as well. 

Struggling to rapidly detect evolving resistance threats like K. variicola 

Clearly, clinical laboratories need to be able to detect K. variicola in cases of bloodstream infection. But it’s not so straightforward: the pathogen is so closely related to its K. pneumoniae cousin that it is often misidentified. This can lead to sub-optimal treatment selection and care for patients in dire need of rapid intervention.

Identification techniques have been developed for MALDI-TOF platforms, next-generation sequencing tools, and PCR instruments. But for bloodstream infections, a quick turnaround time is essential. Any testing algorithm that requires additional technology workflows just for K. variicola is less likely to deliver actionable results in the necessary time frame.

Rapid, targeted results for bloodstream infections with K. variicola detection

At Diasorin, we know how important it is to generate answers for patients with bloodstream infections as quickly as possible. Our FDA-cleared LIAISON PLEX^® Gram-Negative Blood Culture Assay is the only commercially available multiplex assay for bloodstream infection testing that includes K. variicola. This test is intended for use immediately after Gram staining, providing rapid results for a carefully targeted list of potential culprits to align with diagnostic stewardship goals of reducing unnecessary testing. Laboratorians simply take the sample from positive blood culture bottles and run it on our sample-to-answer LIAISON PLEX^® System. (We also offer FDA-cleared assays to help detect gram-positive bacteria and yeast for a comprehensive, streamlined solution to bloodstream infection testing.)

By enabling rapid detection of Klebsiella variicola, laboratories can help clinical partners make timely decisions, such as selecting advanced therapies, enforcing isolation protocols when necessary, and supporting a deeper understanding of this pathogen’s epidemiology and resistance patterns, which is critical for mitigating the spread of antibiotic resistance.

Collectively, these measures improve patient outcomes and strengthen our defense against evolving threats.