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Clinical Microbiology Reviews Mar 2020The causative agent of melioidosis, , a tier 1 select agent, is endemic in Southeast Asia and northern Australia, with increased incidence associated with high levels of... (Review)
Review
The causative agent of melioidosis, , a tier 1 select agent, is endemic in Southeast Asia and northern Australia, with increased incidence associated with high levels of rainfall. Increasing reports of this condition have occurred worldwide, with estimates of up to 165,000 cases and 89,000 deaths per year. The ecological niche of the organism has yet to be clearly defined, although the organism is associated with soil and water. The culture of appropriate clinical material remains the mainstay of laboratory diagnosis. Identification is best done by phenotypic methods, although mass spectrometric methods have been described. Serology has a limited diagnostic role. Direct molecular and antigen detection methods have limited availability and sensitivity. Clinical presentations of melioidosis range from acute bacteremic pneumonia to disseminated visceral abscesses and localized infections. Transmission is by direct inoculation, inhalation, or ingestion. Risk factors for melioidosis include male sex, diabetes mellitus, alcohol abuse, and immunosuppression. The organism is well adapted to intracellular survival, with numerous virulence mechanisms. Immunity likely requires innate and adaptive responses. The principles of management of this condition are drainage and debridement of infected material and appropriate antimicrobial therapy. Global mortality rates vary between 9% and 70%. Research into vaccine development is ongoing.
Topics: Africa; Americas; Animals; Anti-Bacterial Agents; Asia, Southeastern; Bacteremia; Burkholderia pseudomallei; Humans; Melioidosis; Microbiological Techniques; Molecular Diagnostic Techniques; Oceania; Risk Factors; Virulence
PubMed: 32161067
DOI: 10.1128/CMR.00006-19 -
Cells Dec 2020The genus includes a wide range of Gram-negative bacterial species some of which are pathogenic to humans and other vertebrates. The most pathogenic species are , , and... (Review)
Review
The genus includes a wide range of Gram-negative bacterial species some of which are pathogenic to humans and other vertebrates. The most pathogenic species are , , and the members of the complex (Bcc). and , the cause of glanders and melioidosis, respectively, are considered potential bioweapons. The Bcc comprises a subset of species associated with respiratory infections in people with chronic granulomatous disease and cystic fibrosis. Antimicrobial treatment of infections is difficult due to the intrinsic multidrug antibiotic resistance of these bacteria; prophylactic vaccines provide an attractive alternative to counteract these infections. Although commercial vaccines against infections are still unavailable, substantial progress has been made over recent years in the development of vaccines against and . This review critically discusses the current advances in vaccine development against , and the Bcc.
Topics: Animals; Bacterial Vaccines; Burkholderia; Burkholderia Infections; Humans; Vaccines, Attenuated; Vaccines, DNA; Vaccines, Subunit
PubMed: 33322641
DOI: 10.3390/cells9122671 -
Trends in Microbiology Jan 2024is a Gram negative, facultative intracellular bacterium that resides in the rhizosphere of tropical soils. causes melioidosis, which is transmitted by cutaneous entry,...
is a Gram negative, facultative intracellular bacterium that resides in the rhizosphere of tropical soils. causes melioidosis, which is transmitted by cutaneous entry, ingestion, or inhalation of contaminated soil or water. Infection with can cause a wide array of clinical symptoms such as pneumonia, bone, joint, skin, genitourinary, and central nervous system infections, as well as parotid abscesses in children. Mammalian virulence is linked to the intracellular life cycle, which begins with attachment and internalization by host cells. can infect a wide range of eukaryotic cells, including macrophages, monocytes, and neutrophils, as well as nonphagocytic cells. Once internalized, a type 3 secretion system (T3SS) facilitates escape from the phagosome, and the bacteria replicate in the cytoplasm. Autotransporter protein BimA mediates actin polymerization, enabling to spread, cell to cell, using actin-based motility. This process, coupled with the activity of a type 6 secretion system (T6SS-5), results in host membrane fusion and the formation of multinucleated giant cells. Capsule polysaccharides also contribute to virulence and evasion of host innate immunity. Treatment of infections is complicated by the organism’s intrinsic resistance to multiple classes of antimicrobials, largely due to an abundance of efflux pumps and reduced outer membrane permeability. While is commonly associated with endemic ‘hotspots’ in southeast Asia and northern Australia, there is increasing evidence that it is likely endemic in a large range of tropical and subtropical areas, including regions in Africa, South America, the Middle East, Central America, and the Caribbean. Soil and climate conditions favorable for survival are also found in additional areas worldwide. Consequently, it is important for clinical and public health laboratories located outside of high-endemicity areas to be aware of , as well as for improved diagnostic and reporting methods.
Topics: Burkholderia pseudomallei; Burkholderia
PubMed: 37634974
DOI: 10.1016/j.tim.2023.07.008 -
Virulence Dec 2022The soil saprophyte, , is the causative agent of melioidosis, a disease endemic in South East Asia and northern Australia. Exposure to by either inhalation or... (Review)
Review
The soil saprophyte, , is the causative agent of melioidosis, a disease endemic in South East Asia and northern Australia. Exposure to by either inhalation or inoculation can lead to severe disease. rapidly shifts from an environmental organism to an aggressive intracellular pathogen capable of rapidly spreading around the body. The expression of multiple virulence factors at every stage of intracellular infection allows for rapid progression of infection. Following invasion or phagocytosis, resists host-cell killing mechanisms in the phagosome, followed by escape using the type III secretion system. Several secreted virulence factors manipulate the host cell, while bacterial cells undergo a shift in energy metabolism allowing for overwhelming intracellular replication. Polymerisation of host cell actin into "actin tails" propels to the membranes of host cells where the type VI secretion system fuses host cells into multinucleated giant cells (MNGCs) to facilitate cell-to-cell dissemination. This review describes the various mechanisms used by to survive within cells.
Topics: Humans; Burkholderia pseudomallei; Virulence; Actins; Melioidosis; Virulence Factors
PubMed: 36271712
DOI: 10.1080/21505594.2022.2139063 -
Clinical Medicine (London, England) Jan 2022Melioidosis is an infectious disease with high mortality and a wide spectrum of clinical manifestations. Successful treatment requires lengthy antibiotic regimens,...
Melioidosis is an infectious disease with high mortality and a wide spectrum of clinical manifestations. Successful treatment requires lengthy antibiotic regimens, making microbiological diagnosis crucial. In this article, we briefly review the diagnosis and management of melioidosis from the clinician's viewpoint.
Topics: Anti-Bacterial Agents; Burkholderia pseudomallei; Humans; Melioidosis
PubMed: 35078788
DOI: 10.7861/clinmed.2022-0014 -
The American Journal of Tropical... Jun 2023
Topics: Humans; Burkholderia pseudomallei; Melioidosis
PubMed: 37160279
DOI: 10.4269/ajtmh.23-0223 -
Indian Journal of Ophthalmology Nov 2020A 33-year-old lady with history of failed keratoplasty for decompensated cornea due to childhood trauma and secondary glaucoma, post glaucoma drainage implant, with...
A 33-year-old lady with history of failed keratoplasty for decompensated cornea due to childhood trauma and secondary glaucoma, post glaucoma drainage implant, with pseudophakia in the right eye, developed bacterial keratitis following foreign body trauma to corneal graft. Corneal cultures yielded Burkholderia cenocepacia identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF- MS, bioMerieux, France). She healed with topical antibiotics (moxifloxacin 0.5%) in 1 month. Ours is the first report of ocular Burkholderia cenocepacia infection, possibly an under reported, aerobic, organism.
Topics: Adult; Anti-Bacterial Agents; Burkholderia cenocepacia; Eye Infections, Bacterial; Female; Humans; Keratitis; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 33120688
DOI: 10.4103/ijo.IJO_1905_20 -
Microbiological Research Dec 2022The genus Burkholderia has proven potential in improving plant performance. In recent decades, a huge diversity of Burkholderia spp. have been reported with diverse... (Review)
Review
The genus Burkholderia has proven potential in improving plant performance. In recent decades, a huge diversity of Burkholderia spp. have been reported with diverse capabilities of plant symbiosis which could be harnessed to enhance plant growth and development. Colonization of endophytic Burkholderia spp. have been extensively studied through techniques like advanced microscopy, fluorescent labelling, PCR based assays, etc., and found to be systemically distributed in plants. Thus, use of these biostimulant microbes holds the promise of improving quality and quantity of crops. The endophytic Burkholderia spp. have been found to support plant functions along with boosting nutrient availability, especially under stress. Endophytic Burkholderia spp. improve plant survival against deadly pathogens via mechanisms like competition, induced systemic resistance, and antibiosis. At the same time, they are reported to extend plant tolerance towards multiple abiotic stresses especially drought, salinity, and cold. Several attempts have been made to decipher the potential of Burkholderia spp. by genome mining, and these bacteria have been found to harbour genes for plant symbiosis and for providing multiple benefits to host plants. Characteristics specific for host recognition and nutrient acquisition were confirmed in endophytic Burkholderia by genomics and proteomics-based studies. This could pave the way for harnessing Burkholderia spp. for biotechnological applications like biotransformation, phytoremediation, insecticidal activity, antimicrobials, etc. All these make Burkholderia spp. a promising microbial agent in improving plant performance under multiple adversities. Thus, the present review highlights critical roles of endophytic Burkholderia spp., their colonization, alleviation of biotic and abiotic stresses, biotechnological applications and genomic insights.
Topics: Burkholderia; Endophytes; Plant Development; Plants; Symbiosis
PubMed: 36167006
DOI: 10.1016/j.micres.2022.127201 -
Applied Microbiology and Biotechnology Dec 2021Bacteria belonging to the Burkholderia genus are extremely versatile and diverse. They can be environmental isolates, opportunistic pathogens in cystic fibrosis,... (Review)
Review
Bacteria belonging to the Burkholderia genus are extremely versatile and diverse. They can be environmental isolates, opportunistic pathogens in cystic fibrosis, immunocompromised or chronic granulomatous disease patients, or cause disease in healthy people (e.g., Burkholderia pseudomallei) or animals (as in the case of Burkholderia mallei). Since the genus was separated from the Pseudomonas one in the 1990s, the methodological tools to study and characterize these bacteria are evolving fast. Here we reviewed the techniques used in the last few years to update the taxonomy of the genus, to study gene functions and regulations, to deepen the knowledge on the drug resistance which characterizes these bacteria, and to elucidate their mechanisms to establish infections. The availability of these tools significantly impacts the quality of research on Burkholderia and the choice of the most appropriated is fundamental for a precise characterization of the species of interest.Key points• Updated techniques to study the genus Burkholderia were reviewed.• Taxonomy, genomics, assays, and animal models were described.• A comprehensive overview on recent advances in Burkholderia studies was made.
Topics: Animals; Burkholderia; Burkholderia Infections; Burkholderia mallei; Burkholderia pseudomallei; Cystic Fibrosis; Humans
PubMed: 34755214
DOI: 10.1007/s00253-021-11667-3 -
Expert Opinion on Drug Discovery Jul 2021: The increasing threat of antibiotic-resistant pathogens makes it imperative that new antibiotics to combat them are discovered. is a genus of Gram-negative,... (Review)
Review
: The increasing threat of antibiotic-resistant pathogens makes it imperative that new antibiotics to combat them are discovered. is a genus of Gram-negative, non-sporulating bacteria. While ubiquitous and capable of growing within plants and groundwater, they are primarily soil-dwelling organisms. These include the more virulent forms of such as , and the complex (Bcc).: This review provides a synopsis of current research on the natural products isolated from the genus . The authors also cover the research on the drug discovery efforts that have been performed on the natural products derived from .: Though has a small number of pathogenic species, the majority of the genus is avirulent and almost all members of the genus are capable of producing useful antimicrobial products that could potentially lead to the development of novel therapeutics against infectious diseases. The need for discovery of new antibiotics is urgent due to the ever-increasing prevalence of antibiotic-resistant pathogens, coupled with the decline in the discovery of new antibiotics.
Topics: Biological Products; Burkholderia; Burkholderia Infections; Burkholderia pseudomallei; Drug Discovery; Humans
PubMed: 33467922
DOI: 10.1080/17460441.2021.1877655