Burkholderia cepacia is a gram-negative bacteria commonly found in soil and water. The epidemiology of B. cepacia infections varies depending on the population being studied. In individuals with cystic fibrosis, B. cepacia infections are rare but very serious.  

In healthcare settings, B. cepacia infections can occur through contaminated medical equipment or products, such as disinfectants or mouthwash. Outbreaks of B. cepacia infections have been reported in intensive care units, neonatal intensive care units, and other healthcare settings. 

In addition to healthcare-associated infections, B. cepacian infections occur in individuals exposed to contaminated products, such as medical devices, intravenous fluids, or other healthcare products. B. cepacia infections are relatively rare in individuals with cystic fibrosis. In the United States, the generality of B. cepacia infection among individuals with cystic fibrosis was estimated to be less than 3% as of 2018. However, in some regions, such as the United Kingdom, the infection in individuals with cystic fibrosis can be higher.

Outbreaks of healthcare-associated B. cepacia infections have been reported in various countries, including the United States, Canada, and Australia. For example, in 2019, an outbreak of B. cepacia infections was reported in a hospital in the United States, which was linked to contaminated liquid docusate stool softener. 

Scientific Classification: 

Domain: Bacteria  

Phylum: Proteobacteria  

Class: Betaproteobacteria 

Order: Burkholderiales  

Family: Burkholderiaceae  

Genus: Burkholderia  

Species: Burkholderia cepacia 

Structure: 

• Burkholderia cepacia is a gram-negative bacterium with a complex cell envelope structure, including an outer membrane, a peptidoglycan layer, and an inner membrane. The outer membrane contains lipopolysaccharides necessary for the bacterium’s interaction with the environment and host cells. 

• B. cepacia has a rod-shaped morphology and can range in size from 0.5 to 1.5 micrometers in length and 0.2 to 0.4 micrometers in width. It has a single, circular chromosome that contains approximately 7 million base pairs of DNA. 

• B. cepacia has a periplasmic space between the outer and inner membranes, which contains various enzymes and transporters. The bacterium has several necessary appendages for its motility and attachment to surfaces, including flagella, pili, and adhesins. 

Burkholderia cepacia is a complex species composed of several strains or genomovars, which are genetically and antigenically distinct from each other. As a result, there is significant antigenic diversity. 

The current classification scheme for B. cepacia recognizes atleast 20 different genomovars are identified based on differences in their DNA sequences and biochemical properties. Some of the most clinically significant genomovars include: 

• B. cepacia complex genomovar I (B. cenocepacia): This is the most clinically significant within the B. cepacia complex and is associated with severe patient infections and cystic fibrosis. 

• B. cepacia complex genomovar III (B. multivorans): This genomovar is also associated with infections in patients with cystic fibrosis and is often more resistant to antibiotics than other genomovars. 

• B. cepacia complex genomovar VI (B. vietnamiensis): This genomovar is less commonly associated with infections in patients with cystic fibrosis but has been isolated from environmental sources and can cause infections in other populations. 

Burkholderia cepacia is an opportunistic pathogen that can cause a wide range of infections in humans, 

The pathogenesis of B. cepacia is complex and multifactorial, involving several different virulence factors and mechanisms. Some of the key virulence factors and mechanisms involved in the pathogenesis include: 

• B. cepacia has several adhesins that allow it to attach to host cells and tissues, facilitating its colonization and invasion. 

• They can produce biofilms, complex communities of bacteria embedded in a matrix of extracellular polymeric substances. Biofilms can protect the bacteria from host immune defenses and antimicrobial agents, making infections more difficult to treat. 

• The outer membrane of B. cepacia contains lipopolysaccharides, which can activate the host immune system and cause inflammation. 

• B. cepacia can produce various exotoxins, including proteases and siderophores, which can damage host tissues and facilitate the acquisition of nutrients. 

• B. cepacia uses quorum sensing to communicate with other bacteria and coordinate its behavior. It can facilitate the formation of biofilms and other pathogenic behaviors. 

The host defense against Burkholderia cepacia involves a complex interplay between innate and adaptive immune responses and physical barriers such as mucosal surfaces and skin. 

• The innate immune system is the primary defense against B. cepacia. It includes physical barriers such as mucosal surfaces and skin and immune cells such as neutrophils, macrophages, and natural killer cells. These cells can recognize and eliminate B. cepacia through various mechanisms, such as phagocytosis and the production of antimicrobial peptides. 

• The adaptive immune system plays a crucial role in the defense against B. cepacia, particularly in patients with chronic infections. The adaptive immune response involves the activation of T and B cells, which can recognize and target specific components of the bacterium. It can lead to the production of antibodies and the development of immunological memory, providing long-term protection against future infections. 

• Ciliary clearance: Cilia lining the airways in the respiratory tract can help clear B. cepacia and other pathogens by moving mucus and debris out of the lungs. 

• The complement system is a group of proteins that can recognize and eliminate pathogens, including B. cepacia. Activation of the complementary mode can lead to the lysis of bacterial cells and the recruitment of immune cells to the site of infection. 

• Cystic Fibrosis: Burkholderia cepacia is a common cause of lung infections in cystic fibrosis (CF) patients, particularly those with advanced disease. In patients with CF, chronic lung infections with B. cepacia can lead to progressive lung damage and respiratory failure. 

• Bacteremia and sepsis: B. cepacia can cause bloodstream infections in immunocompromised patients or those with indwelling medical devices such as central venous catheters. These infections can lead to sepsis, a potentially life-threatening condition characterized by widespread inflammation and organ failure. 

• Necrotizing pneumonia: B. cepacia has been associated with severe necrotizing pneumonia, a lung infection that can cause tissue death and lung abscesses. This condition can be particularly severe in immunocompromised patients or those with underlying lung disease. 

• Skin and soft tissue infections: B. cepacia can cause severe skin and soft tissue infections, such as necrotizing fasciitis or myonecrosis, leading to tissue death and sepsis. 

• Endocarditis: B. cepacia can cause infective endocarditis, a severe infection of the heart valves. This condition can be particularly severe in patients with underlying heart disease or prosthetic heart valves. 

Diagnosis of Burkholderia cepacia infection can be challenging, as the symptoms can be like other respiratory or bacterial infections. 

•  The standard method for diagnosing B. cepacia infection is by isolating the bacteria from a clinical sample, such as sputum, blood, or urine, and identifying it through culture and biochemical tests. B. cepacia has distinctive colony morphology and can be identified using various culture media. 
• Polymerase Chain Reaction (PCR): PCR is a molecular diagnostic method that can detect the DNA of B. cepacia in clinical samples. PCR can be used as a rapid diagnostic method for identifying B. cepacia, especially in cases where culture results are delayed or inconclusive. 
• Serology: Serological tests can detect antibodies against B. cepacia in a patient’s blood, which can help diagnose chronic infections. However, serology tests are not widely available and unreliable, as cross-reactivity with other bacterial antigens can occur. 
• Imaging studies: Imaging studies like chest X-rays or CT scans can help diagnose B. cepacia lung infections. These studies can reveal the presence of lung abscesses, cavities, or bronchiectasis, which are characteristic findings in patients with chronic B. cepacia infection. 

Controlling the spread of Burkholderia cepacia can be challenging, as the bacteria are resistant to many commonly used disinfectants and can survive for prolonged periods in the environment. 

• Hand hygiene is critical in preventing the spread of B. cepacia in healthcare settings. Healthcare workers should wash their hands frequently with soap and water or use alcohol-based hand sanitizers before and after patient care. 
• Patients with B. cepacia infection should be isolated in single rooms with negative pressure ventilation. When caring for infected patients, healthcare workers should wear personal protective equipment (PPE), such as gloves, gowns, and masks. 
• Environmental surfaces, equipment, and patient care items should be cleaned and disinfected regularly using an appropriate disinfectant. B. cepacia is resistant to many commonly used disinfectants, so it is essential to use an effective disinfectant against the bacteria. 
• Patients with cystic fibrosis or other underlying lung diseases should be screened regularly for B. cepacia infection, and appropriate infection control precautions should be implemented if the infection is detected. 
• Antibiotic stewardship is critical in preventing the development of antibiotic-resistant strains of B. cepacia. Antibiotics should only be used when necessary, and the appropriate antibiotic should be selected based on susceptibility testing. 

https://en.wikipedia.org/wiki/Burkholderia_cepacia_complex

https://www.bing.com/search?q=Burkholderia+cepacia&qs=n&form=QBRE&sp=-1&lq=0&pq=burkholderia+cepacia&sc=11-20&sk=&cvid=373158CE59EC439F91544053AD02AC98&ghsh=0&ghacc=0&ghpl=

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8208758