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Emerging Infectious Diseases Dec 2012The US Public Health Emergency Medical Countermeasures Enterprise convened subject matter experts at the 2010 HHS Burkholderia Workshop to develop consensus...
The US Public Health Emergency Medical Countermeasures Enterprise convened subject matter experts at the 2010 HHS Burkholderia Workshop to develop consensus recommendations for postexposure prophylaxis against and treatment for Burkholderia pseudomallei and B. mallei infections, which cause melioidosis and glanders, respectively. Drugs recommended by consensus of the participants are ceftazidime or meropenem for initial intensive therapy, and trimethoprim/sulfamethoxazole or amoxicillin/clavulanic acid for eradication therapy. For postexposure prophylaxis, recommended drugs are trimethoprim/sulfamethoxazole or co-amoxiclav. To improve the timely diagnosis of melioidosis and glanders, further development and wide distribution of rapid diagnostic assays were also recommended. Standardized animal models and B. pseudomallei strains are needed for further development of therapeutic options. Training for laboratory technicians and physicians would facilitate better diagnosis and treatment options.
Topics: Amoxicillin-Potassium Clavulanate Combination; Animals; Anti-Bacterial Agents; Burkholderia mallei; Burkholderia pseudomallei; Ceftazidime; Disease Models, Animal; Disease Susceptibility; Glanders; Humans; Melioidosis; Meropenem; Post-Exposure Prophylaxis; Risk Factors; Thienamycins; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 23171644
DOI: 10.3201/eid1812.120638 -
Frontiers in Microbiology 2011Burkholderia pseudomallei and Burkholderia mallei are closely related Gram-negative bacteria responsible for the infectious diseases melioidosis and glanders,...
Burkholderia pseudomallei and Burkholderia mallei are closely related Gram-negative bacteria responsible for the infectious diseases melioidosis and glanders, respectively. Autotransporters (ATs) comprise a large and diverse family of secreted and outer membrane proteins that includes virulence-associated invasins, adhesins, proteases, and actin-nucleating factors. The B. pseudomallei K96243 genome contains 11 predicted ATs, eight of which share homologs in the B. mallei ATCC 23344 genome. This review distils key findings from in silico, in vitro, and in vivo studies on the ATs of B. pseudomallei and B. mallei. To date, the best characterized of the predicted ATs of B. pseudomallei and B. mallei is BimA, a predicted trimeric AT mediating actin-based motility which varies in sequence and mode of action between Burkholderia species. Of the remaining eight predicted B. pseudomallei trimeric autotransporters, five of which are also present in B. mallei, two (BoaA and BoaB), have been implicated in bacterial adhesion to epithelial cells. Several predicted Burkholderia ATs are recognized by human humoral and cell-mediated immunity, indicating that they are expressed during infection and may be useful for diagnosis and vaccine-mediated protection. Further studies on the mode of secretion and functions of Burkholderia ATs will facilitate the rational design of control strategies.
PubMed: 21811486
DOI: 10.3389/fmicb.2011.00151 -
Antibiotics (Basel, Switzerland) Nov 2021Bacteria of the genus include pathogenic , and the complex (Bcc). These Gram-negative pathogens have intrinsic drug resistance, which makes treatment of infections...
Bacteria of the genus include pathogenic , and the complex (Bcc). These Gram-negative pathogens have intrinsic drug resistance, which makes treatment of infections difficult. Bcc affects individuals with cystic fibrosis (CF) and the species is associated with one of the worst clinical outcomes. Following the repurposing of auranofin as an antibacterial against Gram-positive bacteria, we previously synthetized auranofin analogs with activity against Gram-negatives. In this work, we show that two auranofin analogs, MS-40S and MS-40, have antibiotic activity against clinical isolates. The compounds are bactericidal against and kill stationary-phase cells and persisters without selecting for multistep resistance. and tolerated high concentrations of MS-40S and MS-40, demonstrating that these compounds have low toxicity in these model organisms. In summary, we show that MS-40 and MS-40S have antimicrobial properties that warrant further investigations to determine their therapeutic potential against infections.
PubMed: 34943654
DOI: 10.3390/antibiotics10121443 -
BMC Microbiology Oct 2012Burkholderia (B.) pseudomallei and B. mallei are genetically closely related species. B. pseudomallei causes melioidosis in humans and animals, whereas B. mallei is the...
BACKGROUND
Burkholderia (B.) pseudomallei and B. mallei are genetically closely related species. B. pseudomallei causes melioidosis in humans and animals, whereas B. mallei is the causative agent of glanders in equines and rarely also in humans. Both agents have been classified by the CDC as priority category B biological agents. Rapid identification is crucial, because both agents are intrinsically resistant to many antibiotics. Matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-TOF MS) has the potential of rapid and reliable identification of pathogens, but is limited by the availability of a database containing validated reference spectra. The aim of this study was to evaluate the use of MALDI-TOF MS for the rapid and reliable identification and differentiation of B. pseudomallei and B. mallei and to build up a reliable reference database for both organisms.
RESULTS
A collection of ten B. pseudomallei and seventeen B. mallei strains was used to generate a library of reference spectra. Samples of both species could be identified by MALDI-TOF MS, if a dedicated subset of the reference spectra library was used. In comparison with samples representing B. mallei, higher genetic diversity among B. pseudomallei was reflected in the higher average Eucledian distances between the mass spectra and a broader range of identification score values obtained with commercial software for the identification of microorganisms. The type strain of B. pseudomallei (ATCC 23343) was isolated decades ago and is outstanding in the spectrum-based dendrograms probably due to massive methylations as indicated by two intensive series of mass increments of 14 Da specifically and reproducibly found in the spectra of this strain.
CONCLUSIONS
Handling of pathogens under BSL 3 conditions is dangerous and cumbersome but can be minimized by inactivation of bacteria with ethanol, subsequent protein extraction under BSL 1 conditions and MALDI-TOF MS analysis being faster than nucleic amplification methods. Our spectra demonstrated a higher homogeneity in B. mallei than in B. pseudomallei isolates. As expected for closely related species, the identification process with MALDI Biotyper software (Bruker Daltonik GmbH, Bremen, Germany) requires the careful selection of spectra from reference strains. When a dedicated reference set is used and spectra of high quality are acquired, it is possible to distinguish both species unambiguously. The need for a careful curation of reference spectra databases is stressed.
Topics: Animals; Bacteriological Techniques; Burkholderia mallei; Burkholderia pseudomallei; Germany; Humans; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 23046611
DOI: 10.1186/1471-2180-12-229 -
Frontiers in Microbiology 2020and are highly pathogenic species which are closely related, but diverse regarding their prophage content. While temperate phages have not yet been isolated from ,...
and are highly pathogenic species which are closely related, but diverse regarding their prophage content. While temperate phages have not yet been isolated from , several phages of , and its non-pathogenic relative have been described. In this study we isolated two phages from and three phages from and determined their morphology, host range, and relationship. All five phages belong to the family , but some of them revealed different host specificities. DNA-DNA hybridization experiments indicated that the phages belong to two groups. One group, composed of ΦE058 (44,121 bp) and ΦE067 (43,649 bp), represents a new subgroup of myoviruses that is not related to known phages. The genomes of ΦE058 and ΦE067 are similar but also show some striking differences. Repressor proteins differ clearly allowing the phages to form plaques on hosts containing the respective other phage. The tail fiber proteins exhibited some minor deviations in the C-terminal region, which may account for the ability of ΦE058, but not ΦE067, to lyse , , and In addition, the integrases and attachment sites of the phages are not related. While ΦE058 integrates into the chromosome within an intergenic region, the ΦE067 prophage resides in the tRNA gene for selenocysteine. Experiments on the structure of phage DNA isolated from particles suggest that the ΦE058 and ΦE067 genomes have a circular conformation.
PubMed: 32528458
DOI: 10.3389/fmicb.2020.01120 -
Journal of Bacteriology Nov 2014Burkholderia pseudomallei, Burkholderia thailandensis, and Burkholderia mallei (the Bptm group) are close relatives with very different lifestyles: B. pseudomallei is an... (Comparative Study)
Comparative Study
Burkholderia pseudomallei, Burkholderia thailandensis, and Burkholderia mallei (the Bptm group) are close relatives with very different lifestyles: B. pseudomallei is an opportunistic pathogen, B. thailandensis is a nonpathogenic saprophyte, and B. mallei is a host-restricted pathogen. The acyl-homoserine lactone quorum-sensing (QS) systems of these three species show a high level of conservation. We used transcriptome sequencing (RNA-seq) to define the quorum-sensing regulon in each species, and we performed a cross-species analysis of the QS-controlled orthologs. Our analysis revealed a core set of QS-regulated genes in all three species, as well as QS-controlled factors shared by only two species or unique to a given species. This global survey of the QS regulons of B. pseudomallei, B. thailandensis, and B. mallei serves as a platform for predicting which QS-controlled processes might be important in different bacterial niches and contribute to the pathogenesis of B. pseudomallei and B. mallei.
Topics: Bacterial Proteins; Burkholderia; Burkholderia mallei; Burkholderia pseudomallei; Gene Expression Regulation, Bacterial; Quorum Sensing; Regulon; Species Specificity
PubMed: 25182491
DOI: 10.1128/JB.01974-14 -
BMC Infectious Diseases Feb 2013Burkholderia mallei and B. pseudomallei are two closely related species of highly virulent bacteria that can be difficult to detect. Pathogenic Burkholderia are endemic...
BACKGROUND
Burkholderia mallei and B. pseudomallei are two closely related species of highly virulent bacteria that can be difficult to detect. Pathogenic Burkholderia are endemic in many regions worldwide and cases of infection, sometimes brought by travelers from unsuspected regions, also occur elsewhere. Rapid, sensitive methods for identification of B. mallei and B. pseudomallei are urgently needed in the interests of patient treatment and epidemiological surveillance.
METHODS
Signature sequences for sensitive, specific detection of pathogenic Burkholderia based on published genomes were identified and a qPCR assay was designed and validated.
RESULTS
A single-reaction quadruplex qPCR assay for the detection of pathogenic Burkholderia, which includes a marker for internal control of DNA extraction and amplification, was developed. The assay permits differentiation of B. mallei and B. pseudomallei strains, and probit analysis showed a very low detection limit. Use of a multicopy signature sequence permits detection of less than 1 genome equivalent per reaction.
CONCLUSIONS
The new assay permits rapid detection of pathogenic Burkholderia and combines enhanced sensitivity, species differentiation, and inclusion of an internal control for both DNA extraction and PCR amplification.
Topics: Animals; Bacterial Proteins; Burkholderia mallei; Burkholderia pseudomallei; Glanders; Humans; Melioidosis; Molecular Typing; Multiplex Polymerase Chain Reaction; Real-Time Polymerase Chain Reaction; Reproducibility of Results; Sensitivity and Specificity
PubMed: 23409683
DOI: 10.1186/1471-2334-13-86 -
Current Opinion in Microbiology Feb 2016The Burkholderia genus contains a group of soil-dwelling Gram-negative organisms that are prevalent in warm and humid climates. Two species in particular are able to... (Review)
Review
The Burkholderia genus contains a group of soil-dwelling Gram-negative organisms that are prevalent in warm and humid climates. Two species in particular are able to cause disease in animals, B. mallei primarily infects Equus spp. and B. pseudomallei (BPS), that is able to cause potentially life-threatening disease in humans. BPS is naturally resistant to many antibiotics and there is no vaccine available. Although not a specialised human pathogen, BPS possesses a large genome and many virulence traits that allow it to adapt and survive very successfully in the human host. Key to this survival is the ability of BPS to replicate intracellularly. In this review we highlight recent advances in our understanding of the intracellular survival of BPS, including how it overcomes host immune defenses and other challenges to establish its niche and then spread the infection. Knowledge of these mechanisms increases our capacity for therapeutic interventions against a well-armed foe.
Topics: Actins; Animals; Burkholderia pseudomallei; Cytoplasm; DNA Replication; Giant Cells; Host-Pathogen Interactions; Humans; Melioidosis; Type VI Secretion Systems; Virulence; Virulence Factors
PubMed: 26803404
DOI: 10.1016/j.mib.2015.11.007 -
Molecules (Basel, Switzerland) Dec 2019, the causative agent of glanders, and , the causative agent of melioidosis in humans and animals, are genetically closely related. The high infectious potential of both...
, the causative agent of glanders, and , the causative agent of melioidosis in humans and animals, are genetically closely related. The high infectious potential of both organisms, their serological cross-reactivity, and similar clinical symptoms in human and animals make the differentiation from each other and other species challenging. The increased resistance against many antibiotics implies the need for fast and robust identification methods. The use of Raman microspectroscopy in microbial diagnostic has the potential for rapid and reliable identification. Single bacterial cells are directly probed and a broad range of phenotypic information is recorded, which is subsequently analyzed by machine learning methods. were handled under biosafety level 1 (BSL 1) conditions after heat inactivation. The clusters of the spectral phenotypes and the diagnostic relevance of the spp. were considered for an advanced hierarchical machine learning approach. The strain panel for training involved 12 , 13 and 11 other spp. type strains. The combination of top- and sub-level classifier identified the mallei-complex with high sensitivities (>95%). The reliable identification of unknown and strains highlighted the robustness of the machine learning-based Raman spectroscopic assay.
Topics: Bacterial Typing Techniques; Burkholderia mallei; Cluster Analysis; Humans; Machine Learning; Spectrum Analysis, Raman; Workflow
PubMed: 31835527
DOI: 10.3390/molecules24244516 -
Infection and Immunity Aug 2016Burkholderia mallei is the causative agent of glanders, an incapacitating disease with high mortality rates in respiratory cases. Its endemicity and ineffective...
Burkholderia mallei is the causative agent of glanders, an incapacitating disease with high mortality rates in respiratory cases. Its endemicity and ineffective treatment options emphasize its public health threat and highlight the need for a vaccine. Live attenuated vaccines are considered the most viable vaccine strategy for Burkholderia, but single-gene-deletion mutants have not provided complete protection. In this study, we constructed the select-agent-excluded B. mallei ΔtonB Δhcp1 (CLH001) vaccine strain and investigated its ability to protect against acute respiratory glanders. Here we show that CLH001 is attenuated, safe, and effective at protecting against lethal B. mallei challenge. Intranasal administration of CLH001 to BALB/c and NOD SCID gamma (NSG) mice resulted in complete survival without detectable colonization or abnormal organ histopathology. Additionally, BALB/c mice intranasally immunized with CLH001 in a prime/boost regimen were fully protected against lethal challenge with the B. mallei lux (CSM001) wild-type strain.
Topics: Animals; Antibodies, Bacterial; Antigens, Bacterial; Bacterial Vaccines; Burkholderia mallei; Disease Models, Animal; Female; Glanders; Immunization; Immunization, Secondary; Immunocompromised Host; Immunoglobulin G; Mice; Mutation; Vaccines, Attenuated
PubMed: 27271739
DOI: 10.1128/IAI.00328-16