-
Seminars in Respiratory and Critical... Dec 2019Although survival of individuals with cystic fibrosis (CF) has been continuously improving for the past 40 years, respiratory failure secondary to recurrent pulmonary... (Review)
Review
Although survival of individuals with cystic fibrosis (CF) has been continuously improving for the past 40 years, respiratory failure secondary to recurrent pulmonary infections remains the leading cause of mortality in this patient population. Certain pathogens such as , methicillin-resistant , and species of the complex continue to be associated with poorer clinical outcomes including accelerated lung function decline and increased mortality. In addition, other organisms such as anaerobes, viruses, and fungi are increasingly recognized as potential contributors to disease progression. Culture-independent molecular methods are also being used for diagnostic purposes and to examine the interaction of microorganisms in the CF airway. Given the importance of CF airway infections, ongoing initiatives to promote understanding of the epidemiology, clinical course, and treatment options for these infections are needed.
Topics: Bacterial Infections; Burkholderiaceae; Cystic Fibrosis; Humans; Methicillin-Resistant Staphylococcus aureus; Microbiota; Mycoses; Pseudomonas aeruginosa; Respiratory Tract Infections; Virus Diseases
PubMed: 31887768
DOI: 10.1055/s-0039-1698464 -
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 -
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 -
Nature Communications Mar 2021Prokaryotic cell transcriptomics has been limited to mixed or sub-population dynamics and individual cells within heterogeneous populations, which has hampered further...
Prokaryotic cell transcriptomics has been limited to mixed or sub-population dynamics and individual cells within heterogeneous populations, which has hampered further understanding of spatiotemporal and stage-specific processes of prokaryotic cells within complex environments. Here we develop a 'TRANSITomic' approach to profile transcriptomes of single Burkholderia pseudomallei cells as they transit through host cell infection at defined stages, yielding pathophysiological insights. We find that B. pseudomallei transits through host cells during infection in three observable stages: vacuole entry; cytoplasmic escape and replication; and membrane protrusion, promoting cell-to-cell spread. The B. pseudomallei 'TRANSITome' reveals dynamic gene-expression flux during transit in host cells and identifies genes that are required for pathogenesis. We find several hypothetical proteins and assign them to virulence mechanisms, including attachment, cytoskeletal modulation, and autophagy evasion. The B. pseudomallei 'TRANSITome' provides prokaryotic single-cell transcriptomics information enabling high-resolution understanding of host-pathogen interactions.
Topics: Animals; Bacterial Proteins; Burkholderia pseudomallei; Cell Line, Tumor; Cell Membrane; Computational Biology; Cytoplasm; Gene Expression Profiling; Genes, Bacterial; HEK293 Cells; Host-Pathogen Interactions; Humans; Melioidosis; Mice; Mice, Inbred BALB C; RAW 264.7 Cells; Single-Cell Analysis; Vacuoles; Virulence; Virulence Factors
PubMed: 33772012
DOI: 10.1038/s41467-021-22169-1 -
Applied and Environmental Microbiology Mar 2021Mucoromycota representatives are known to harbor two types of endohyphal bacteria (EHB)--related endobacteria (BRE) and -related endobacteria (MRE). While both BRE and...
Mucoromycota representatives are known to harbor two types of endohyphal bacteria (EHB)--related endobacteria (BRE) and -related endobacteria (MRE). While both BRE and MRE occur in fungi representing all subphyla of Mucoromycota, their distribution is not well studied. Therefore, it is difficult to resolve the evolutionary history of these associations in favor of one of the following two alternative hypotheses explaining their origin: "early invasion" and "late invasion." Our main goal was to fill this knowledge gap by surveying Mucoromycota fungi for the presence of EHB. We screened 196 fungal strains from 16 genera using a PCR-based approach to detect bacterial 16S rRNA genes, complemented with fluorescence hybridization (FISH) imaging to confirm the presence of bacteria within the hyphae. We detected in ca. 20% of fungal strains. Some of these bacteria clustered phylogenetically with previously described BRE clades, whereas others grouped with free-living Importantly, the latter were detected in Umbelopsidales, which previously were not known to harbor endobacteria. Our results suggest that this group of EHB is recruited from the environment, supporting the late invasion scenario. This pattern complements the early invasion scenario apparent in the BRE clade of EHB. Bacteria living within fungal hyphae present an example of one of the most intimate relationships between fungi and bacteria. Even though there are several well-described examples of such partnerships, their prevalence within the fungal kingdom remains unknown. Our study focused on early divergent terrestrial fungi in the phylum Mucoromycota. We found that ca. 20% of the strains tested harbored bacteria from the family Not only did we confirm the presence of bacteria from previously described endosymbiont clades, we also identified a new group of endohyphal representing the genus We established that more than half of the screened strains were positive for bacteria from this new group. We also determined that, while previously described BRE codiverged with their fungal hosts, symbionts did not.
Topics: Burkholderiaceae; Fungi; Hyphae; In Situ Hybridization, Fluorescence; Polymerase Chain Reaction; RNA, Bacterial; RNA, Ribosomal, 16S
PubMed: 33483310
DOI: 10.1128/AEM.02707-20 -
Viruses Jul 2021The increasing prevalence and worldwide distribution of multidrug-resistant bacterial pathogens is an imminent danger to public health and threatens virtually all... (Review)
Review
The increasing prevalence and worldwide distribution of multidrug-resistant bacterial pathogens is an imminent danger to public health and threatens virtually all aspects of modern medicine. Particularly concerning, yet insufficiently addressed, are the members of the complex (Bcc), a group of at least twenty opportunistic, hospital-transmitted, and notoriously drug-resistant species, which infect and cause morbidity in patients who are immunocompromised and those afflicted with chronic illnesses, including cystic fibrosis (CF) and chronic granulomatous disease (CGD). One potential solution to the antimicrobial resistance crisis is phage therapy-the use of phages for the treatment of bacterial infections. Although phage therapy has a long and somewhat checkered history, an impressive volume of modern research has been amassed in the past decades to show that when applied through specific, scientifically supported treatment strategies, phage therapy is highly efficacious and is a promising avenue against drug-resistant and difficult-to-treat pathogens, such as the Bcc. In this review, we discuss the clinical significance of the Bcc, the advantages of phage therapy, and the theoretical and clinical advancements made in phage therapy in general over the past decades, and apply these concepts specifically to the nascent, but growing and rapidly developing, field of Bcc phage therapy.
Topics: Bacteriophages; Burkholderia cepacia complex; Humans; Phage Therapy
PubMed: 34372537
DOI: 10.3390/v13071331 -
Emerging Infectious Diseases 2021We studied 20 confirmed or suspected cases of melioidosis in children in Ceará, Brazil, during 1989-2019. We observed a high death rate, severe signs and symptoms, and...
We studied 20 confirmed or suspected cases of melioidosis in children in Ceará, Brazil, during 1989-2019. We observed a high death rate, severe signs and symptoms, and substantial environmental exposure. These data suggest that childhood melioidosis might be more severe in Brazil than in other regions.
Topics: Brazil; Burkholderia pseudomallei; Child; Environmental Exposure; Humans; Melioidosis
PubMed: 34013871
DOI: 10.3201/eid2706.200154 -
Annual Review of Microbiology Sep 2023species complex (RSSC) strains are devastating plant pathogens distributed worldwide. The primary cell density-dependent gene expression system in RSSC strains is... (Review)
Review
species complex (RSSC) strains are devastating plant pathogens distributed worldwide. The primary cell density-dependent gene expression system in RSSC strains is quorum sensing (QS). It regulates the expression of about 30% of all genes, including those related to cellular activity, primary and secondary metabolism, pathogenicity, and more. The regulatory elements encoded by the operon and gene play vital roles. RSSC strains use methyl 3-hydroxymyristate (3-OH MAME) or methyl 3-hydroxypalmitate (3-OH PAME) as the QS signal. Each type of RSSC strain has specificity in generating and receiving its QS signal, but their signaling pathways might not differ significantly. In this review, I describe the genetic and biochemical factors involved in QS signal input and the regulatory network and summarize control of the QS system, new cell-cell communications, and QS-dependent interactions with soil fungi.
Topics: Quorum Sensing; Ralstonia solanacearum; Virulence; Signal Transduction
PubMed: 37100406
DOI: 10.1146/annurev-micro-032521-030537 -
Expert Opinion on Biological Therapy Dec 2019: Two important pathogenic species within the genus , namely () and (), are the causative agents of the life-threatening diseases melioidosis and glanders,... (Review)
Review
: Two important pathogenic species within the genus , namely () and (), are the causative agents of the life-threatening diseases melioidosis and glanders, respectively. Due to their high mortality rate and potential for aerosolization, they have gained interest as potential biothreat agents and are classified as Tier 1 Select Agents.: The manuscript provides an overview of the literature covering the efforts taken in the last 10 years to develop new therapeutics measures against both and , with attention on novel therapeutic agents.: As a result of the complicated antibiotic regimens necessary to treat these infections, development of novel therapeutics is needed to treat both diseases. In recent years, the understanding of the pathogenesis of has improved significantly and so have the efforts to develop novel therapeutic agents with high efficacy, either alone, or in combination with conventional antibiotics.
Topics: Animals; Biological Products; Burkholderia mallei; Burkholderia pseudomallei; Glanders; Humans; Melioidosis
PubMed: 31590578
DOI: 10.1080/14712598.2019.1677602 -
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