Burkholderia cenocepacia is a Gram-negative, rod-shaped bacterium that is commonly found in soil and water environments and may also be associated with plants and animals, particularly as a human pathogen.
[1] It is one of over 20 species in the Burkholderia cepacia complex (Bcc) and is notable due to its virulence factors and inherent antibiotic resistance that render it a prominent opportunistic pathogen responsible for life-threatening, nosocomial infections in immunocompromised patients, such as those with cystic fibrosis or chronic granulomatous disease.
[8] Exchange of genetic material between species of the Bcc has resulted in a reticulated phylogeny that presents an obstacle to diagnostic classification at the species-level.
[17][18] In addition to the multireplicon structure, the genome contains several insertion sequences and can rapidly mutate during infections, which contribute to B. cenocepacia's unique adaptability and ability to acquire diverse catabolic functions.
Ornibactin is the most important iron uptake system and can sustain the bacteria in an iron-deficient environment even without the production of functioning pyochelin or SA.
[12][24] High potential of Bcc species, including B. cenocepacia, as a biocontrol of plant-growth promoting agents has been demonstrated; however, the mechanisms that support this are not known.
[12] Burkholderia cenocepacia was the dominant genomovar recovered in a study of bacteria in the rhizosphere of maize in China, pointing to endosymbiotic attributes with plants in soil.
[6] One kind of cell-to-cell communication employed by B. cenocepacia is quorum sensing, which is the detection of fluctuations in cell density and usage of this information to regulate functions such as the formation of biofilms.
[30] In cystic fibrosis, it can cause "cepacia syndrome," which is characterized by a rapidly progressive fever, uncontrolled bronchopneumonia, weight loss, and in some cases, death.
This has reportedly been used for the first gene-editing of mitochondria – for which a team at the Broad Institute developed a new kind of CRISPR-free base editor, called DdCBE, using the toxin.
[36][37][38] See also: Burkholderia thailandensis sRNA The structural factors that contribute to the antibiotic resistance of B. cenocepacia include: an impermeable outer membrane, an efflux pump mechanism, and the production of a beta-lactamase.
[40] Virulence in Burkholderia cenocepacia is widely attributed to biofilm formation, siderophore production, and QS signaling - each of which affect how the species adapts in various environmental conditions.
[22] Compared to other infectious agents found in cystic fibrosis patients, the Bcc complex demonstrates the greatest association with increased morbidity and mortality.
[45] Compared to other species in the Bcc complex, B. cenocepacia was shown to possibly accelerate BMI decline and FEV1 (forced expiration) at the greatest rate, leading to worse prognoses for cystic fibrosis patients.
[46] Overall, in patients with cystic fibrosis, the genomovar status of the Bcc has a significant influence on the success of clinical interventions, as well as the temporal progression of the condition.
[47] Given the opportunistic nature of the Bcc complex and B. cenocepacia, the severity of respiratory infections is considered to be a significant conflict for applications in biotechnology.