Can a Sepsis Panel Showing Klebsiella Be Considered Bacteremia?
Yes, a sepsis panel (blood culture) that grows Klebsiella definitively represents bacteremia, which is defined as the presence of viable bacteria in the bloodstream. 1, 2
Understanding the Terminology
Bacteremia is a microbiological finding—the presence of bacteria in blood—while sepsis is a clinical diagnosis. 2 When your blood culture grows Klebsiella, this is bacteremia by definition. Whether this constitutes sepsis depends on the clinical context (presence of systemic inflammatory response and organ dysfunction). 2
Confirming True Bacteremia vs. Contamination
The critical question is whether this represents true bacteremia or contamination:
Klebsiella is NOT a typical contaminant organism. Unlike coagulase-negative staphylococci or Corynebacterium species, Klebsiella pneumoniae is a clinically significant pathogen when isolated from blood cultures. 3, 4
A single positive blood culture with Klebsiella should be considered true bacteremia unless there are compelling reasons to suspect contamination (which is rare with this organism). 1
Contamination rates for blood cultures range from 1% to 4.5%, but this primarily applies to skin flora organisms, not enteric gram-negative rods like Klebsiella. 3, 1
Clinical Significance of Klebsiella Bacteremia
Klebsiella bacteremia is a serious infection requiring immediate antimicrobial therapy:
Klebsiella pneumoniae is responsible for significant hospital-acquired infections including septicemia, with documented mortality influenced by underlying disease, patient age, and infection site. 4, 5
Common sources include urinary tract (27%), gastrointestinal tract (24%), intravenous sites (20%), and pulmonary system (15%). 5
The organism is medically important and particularly affects immunocompromised hosts, including critically ill patients. 4
Recommended Confirmation Approach
While a single positive culture with Klebsiella is clinically significant, optimal practice includes obtaining 2-3 sets of blood cultures to achieve sensitivity exceeding 99% and strengthen diagnostic certainty. 1
If multiple blood culture sets grow the same organism, this definitively confirms true bacteremia rather than contamination. 1
In critically ill patients, all blood culture sets can be drawn simultaneously without time intervals between collections. 3, 1
Treatment Implications
Klebsiella bacteremia requires targeted antimicrobial therapy based on susceptibility testing:
Piperacillin is FDA-approved for septicemia/bacteremia caused by Klebsiella species. 6
Be aware of increasing multidrug resistance and extended-spectrum beta-lactamase (ESBL)-producing Klebsiella strains, which complicate treatment. 4
Mortality is influenced by the portal of entry—deaths occur more frequently with pulmonary or abdominal sources compared to urinary tract or IV site sources. 5