The Burkholderia cepacia complex (Bcc) refers to a group of closely related bacteria. These microorganisms are commonly found in various natural environments, including soil and water. Bcc bacteria are recognized as opportunistic pathogens, meaning they primarily cause infections in individuals with underlying health conditions or weakened immune systems. They generally pose little medical risk to healthy people.
Vulnerable Populations and Risk Factors
Certain pre-existing health conditions increase susceptibility to Burkholderia cepacia complex infections. People with cystic fibrosis (CF) are a primary at-risk group, as their compromised lung environment, characterized by thick mucus and chronic inflammation, creates a favorable setting for these bacteria to establish and persist. Burkholderia cenocepacia and Burkholderia multivorans are among the most prevalent Bcc species found in CF patients.
Beyond CF, individuals with chronic granulomatous disease (CGD) are also vulnerable due to defects in their immune cells’ ability to fight off certain bacteria. Immunocompromised individuals, such as cancer patients undergoing chemotherapy or organ transplant recipients, are also at risk. Hospitalization, particularly in intensive care units where patients may have indwelling medical devices or severe illnesses, can increase exposure and susceptibility to Bcc infections.
Sources and Transmission Pathways
Burkholderia cepacia complex bacteria can be acquired from several sources and through distinct transmission pathways. Environmental exposure is a common route, as these bacteria naturally inhabit water and soil. This broad environmental presence means Bcc can potentially contaminate various non-sterile aqueous solutions and surfaces.
Person-to-person transmission is another significant pathway, especially in healthcare settings and among cystic fibrosis patients. This can occur through direct contact or indirectly via contaminated hands of healthcare providers or caregivers. Additionally, outbreaks have been linked to contaminated commercial products, including medical devices, disinfectant solutions, and certain pharmaceutical preparations, such as oral liquid medications or prefilled saline flush syringes.
Symptoms and Associated Health Conditions
The health impact of a Burkholderia cepacia complex infection can vary widely, ranging from asymptomatic colonization to severe, life-threatening conditions. Some individuals may become colonized with Bcc, meaning the bacteria are present without causing active symptoms. This colonization can persist for extended periods, particularly in the respiratory tracts of susceptible individuals.
When an active infection develops, it frequently manifests as a lung infection, often resembling pneumonia. Symptoms can include fever, a persistent cough, and difficulty breathing. The severity varies depending on the individual’s underlying health and the specific Bcc strain involved.
A particularly severe outcome, “cepacia syndrome,” involves a rapid and aggressive decline in lung function coupled with sepsis, a life-threatening response to infection. This syndrome is associated with Bcc infections, especially in cystic fibrosis patients, and can lead to rapid deterioration and can be fatal. Infection with Bcc, particularly Burkholderia cenocepacia, is often a contraindication for lung transplantation in CF patients due to the increased mortality risk.
Diagnosis and Management of Infection
Diagnosing a Burkholderia cepacia complex infection involves laboratory identification of the bacteria from clinical samples. Healthcare providers collect specimens such as sputum, blood, or respiratory secretions, which are then cultured. Specialized culture media, like Burkholderia cepacia agar, are often used to isolate and identify these bacteria, as they inhibit the growth of other common microbes.
Managing Bcc infections is challenging due to the bacteria’s inherent resistance to many common antibiotics. This resistance means Bcc can withstand several antibiotic classes, including aminoglycosides and polymyxin B. Treatment often requires a combination of antibiotics, selected based on the susceptibility profile of the isolated Bcc strain.
Susceptibility testing is a routine step to guide treatment, helping clinicians choose the most effective antibiotic regimen. Antibiotics are frequently administered intravenously for severe infections, ensuring adequate drug concentrations at the infection site. Infection control practices are also implemented in healthcare settings to limit the spread of these resistant bacteria among vulnerable patients.