RESUMEN
Glanders, a highly contagious and often fatal disease affecting equids, is caused by Burkholderia mallei. Although sporadic cases of equine glanders have recently been documented in Mongolia, genome sequencing and molecular studies of the bacteria within this region are lacking. This study provided the first molecular characterization of B. mallei isolated from four native Mongolian horses from two different provinces in 2019 and 2022 by applying whole-genome sequencing with two SNP types (previously developed genotyping with 15 SNP markers that provide global coverage of the B. mallei population and the core genome coding SNP typing developed in this study). The Mongolian isolates were located within the L3B1 cluster, which was previously associated with the V-120 strain from Russia. Within the L3B1 cluster shared by neighboring countries, they were in a unique subbranch. In this study, specific SNP markers unique to the Mongolian strains were identified to track these strains using a high-resolution melting analysis (HRMA). This study revealed the unique phylogenetic background of Mongolian strains isolated from the eastern part of Mongolia. HRMA specific to the Mongolian subbranch may contribute to the molecular epidemiological monitoring of glanders in Mongolia and surrounding countries.
Asunto(s)
Burkholderia mallei , Muermo , Enfermedades de los Caballos , Filogenia , Polimorfismo de Nucleótido Simple , Animales , Caballos/microbiología , Mongolia , Burkholderia mallei/genética , Burkholderia mallei/clasificación , Burkholderia mallei/aislamiento & purificación , Muermo/microbiología , Enfermedades de los Caballos/microbiología , Secuenciación Completa del Genoma , Genoma BacterianoRESUMEN
Glanders is a highly contagious and potentially serious disease caused by Burkholderia mallei, a Tier 1 select agent. In this study, we raised a monoclonal antibody (mAb) against the lipopolysaccharide (LPS) of B. mallei and developed a competitive enzyme-linked immunosorbent assay (cELISA) for B. mallei infection. Using the titrated optimal conditions of B. mallei-LPS (2 ng) for microtiter plate coating, sample serum dilution at 1:20 and 3.5 ng/µL anti-LPS mAb B5, the cutoff value of the cELISA was determined using serum samples from 136 glanders-free seronegative horses in Hong Kong. All calculated percentage inhibition (PI) values from these seronegative samples were below 39.6% inhibition (1.5 standard deviations above mean PI) and was used as the cutoff value. The diagnostic sensitivity of the developed LPS-based cELISA was first evaluated using sera from donkeys and mice inoculated with B. mallei. An increasing trend of PI values above the defined cELISA cutoff observed in the donkey and mouse sera suggested positive detection of anti-LPS antibodies. The sensitivity and specificity of the LPS-based cELISA was further evaluated using 31 serologically positive horse sera from glanders outbreaks in Bahrain and Kuwait, of which 30 were tested positive by the cELISA; and 21 seronegative horse sera and 20 seronegative donkey sera from Dubai, of which all were tested negative by the cELISA. A cELISA with high sensitivity (97.2%) and specificity (100%) for the detection of B. mallei antibodies in different animals was developed.
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Burkholderia mallei/aislamiento & purificación , Ensayo de Inmunoadsorción Enzimática/métodos , Muermo/diagnóstico , Enfermedades de los Caballos/diagnóstico , Pruebas Serológicas/métodos , Animales , Anticuerpos Antibacterianos/sangre , Burkholderia mallei/inmunología , Equidae , Muermo/sangre , Muermo/microbiología , Enfermedades de los Caballos/sangre , Enfermedades de los Caballos/microbiología , Caballos , Ratones , Sensibilidad y EspecificidadRESUMEN
Glanders is a relatively unknown zoonotic disease caused by Burkholderia mallei. This bacterium affect solipeds and humans, and can be used as a biological warfare. Glanders is characterized as an occupational disease. We report the case of an 11-year-old boy who was presented to an emergency department with chest pain and dyspnea. He evolved into septic shock, pneumonia, and multiple abscesses. B. mallei was found in the exudate culture. Human infection is rare and difficult to confirm. The knowledge on glanders is important for differential diagnosis from other serious illnesses causing pneumonia and multiple abscesses.
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Burkholderia mallei/aislamiento & purificación , Muermo/diagnóstico , Niño , Muermo/tratamiento farmacológico , Humanos , MasculinoRESUMEN
Abstract Glanders is a relatively unknown zoonotic disease caused by Burkholderia mallei. This bacterium affect solipeds and humans, and can be used as a biological warfare. Glanders is characterized as an occupational disease. We report the case of an 11-year-old boy who was presented to an emergency department with chest pain and dyspnea. He evolved into septic shock, pneumonia, and multiple abscesses. B. mallei was found in the exudate culture. Human infection is rare and difficult to confirm. The knowledge on glanders is important for differential diagnosis from other serious illnesses causing pneumonia and multiple abscesses.
Asunto(s)
Humanos , Animales , Niño , Burkholderia mallei/aislamiento & purificación , Muermo/diagnóstico , Muermo/terapiaRESUMEN
Burkholderia (B.) mallei is the causative agent of glanders in Equidae. This study describes the first record of the Turkey 10 strain of B. mallei in glanderous horses in Northeastern of Brazil. This description should contribute to the future actions of diagnosis, control, and eradication of this disease in Brazil.
Asunto(s)
Burkholderia mallei/aislamiento & purificación , Muermo/microbiología , Animales , Brasil , Burkholderia mallei/genética , Burkholderia mallei/fisiología , Genoma Bacteriano , CaballosRESUMEN
BACKGROUND AND AIM: Burkholderia mallei, the etiologic agent of the disease known as glanders. Clinical and bacteriological diagnosis of glanders is difficult in the early stages of the disease. Currently, mallein (allergic hypersensitivity test) is used for the diagnosis of glanders. The mallein test requires an experienced laboratory person and lasts 48 h. Therefore, in order to quickly diagnose the disease, especially in areas (such as the borders of the country) that cannot be kept animals, new methods should be used to identify the disease. The Rose Bengal is a serological diagnostic test and has been recommended by the World Organization for Animal Health (OIE). In this study, the Rose Bengal test (RBT) was evaluated for the diagnosis of equine glanders, and its diagnostic was compared with mallein test. MATERIALS AND METHODS: Sera from 70 naturally infected culture-positive horses, 3 equines that were sensitized by injecting antigen and 110 healthy equines were tested. Specificity and sensitivity of RBT and mallein test when testing culture-positive equines were calculated. RESULTS: Diagnosis of glanders with both methods yield the same results, but Rose Bengal test is much faster than mallein test for diagnosis of equine glanders. CONCLUSION: By comparative RBT with mallein test, it can be considered, RBT test has been used for rapid detection of glanders with features such as, ease of use and can be applicable without specialized equipment and trained personnel. Because the RBT is simpler and rapid to perform, the inclusion of the test as a supplementary test for the diagnosis of glanders in field conditions is recommended.
Asunto(s)
Burkholderia mallei/aislamiento & purificación , Muermo/diagnóstico , Rosa Bengala/química , Pruebas Serológicas/veterinaria , Animales , Burkholderia mallei/química , Caballos , Factores de TiempoRESUMEN
BACKGROUND: Burkholderia mallei is a Gram-negative bacterium that causes glanders, a zoonotic disease, especially in equine populations (e.g. horses, donkeys, and mules). B. mallei usually grows slowly on most culture media, and this property makes it difficult to isolate from clinical specimens. One of the problems is that B. mallei is easily overgrown by other bacteria, especially in animal specimens collected from non-sterile sites. The aim of this study was to develop a new selective agar for the laboratory diagnosis of glanders. We formulated a new agar, named BM agar, to enrich B. mallei growth, but inhibit the growth of other bacteria and fungi based on their antimicrobial profiles. We compared the growth of B. mallei on BM with Xie's and PC agars, the two previously described selective agars for B. mallei. RESULTS: BM agar could sufficiently grow almost all of the tested B. mallei strains within 72 h: only one out of the 38 strains grew scantly after 72 h of incubation. BM agar was further tested with other Burkholderia species and various bacterial species commonly found in the nasal cavities and on the skin of horses. We have found that other Burkholderia species including B. pseudomallei and B. thailandensis can grow on BM agar, but non-Burkholderia species cannot. Furthermore, the specificities of the three selective agars were tested with or without spiking B. mallei culture into clinical specimens of non-sterile sites collected from healthy horses. The results showed that BM agar inhibited growths of fungi and other bacterial species better than PC and Xie's agars. We have also found that growth of B. mallei on BM agar was equivalent to that on 5% horse blood agar and was significantly greater than those on the other two agars (P < 0.05). CONCLUSIONS: We believe that BM agar can be used to efficiently isolate B. mallei from mixed samples such as those typically collected from horses and other contaminated environments.
Asunto(s)
Burkholderia mallei/aislamiento & purificación , Medios de Cultivo/química , Muermo/diagnóstico , Muermo/microbiología , Agar , Animales , Burkholderia mallei/crecimiento & desarrollo , CaballosRESUMEN
Burkholderia mallei, a potential biothreat agent is the aetiological agent of glanders, a zoonotic disease primarily affecting equines. B. mallei shares close genetic proximity with B. pseudomallei, the aetiological agent of melioidosis. Hence, molecular detection of B. mallei and its differentiation from B. pseudomallei has always been challenging. Early diagnosis of glanders is critical for timely treatment in humans and disease containment in animals. In this study a recombinase polymerase amplification-lateral flow (RPA-LF) assay has been developed for early and accurate detection of B. mallei. RPA-LF assay was found to be highly sensitive and detected as low as 10 fg genomic DNA of B. mallei. The assay was highly specific and could differentiate B. mallei and B. pseudomallei. The assay also detected B. mallei in artificially spiked blood, tap water and garden soil. The established assay is simple, rapid and does not require complex instrumentation. The field deployable assay can have better implications in rapid glanders diagnosis and environmental detection of B. mallei over PCR-based detection tools in glanders endemic areas with limited laboratory resources.
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Burkholderia mallei/genética , Burkholderia mallei/aislamiento & purificación , ADN Bacteriano/genética , Técnicas de Amplificación de Ácido Nucleico/veterinaria , Animales , Sangre/microbiología , Caballos , Humanos , Técnicas de Amplificación de Ácido Nucleico/métodos , Recombinasas , Microbiología del Suelo , Microbiología del AguaRESUMEN
Background: Diagnostic tools designed to target Burkholderia pseudomallei, the causative agent of melioidosis that was classified as a Tier 1 Select Agent by the U.S. Centers for Disease Control and Prevention, have typically suffered from false-positive and false-negative results because of a lack of understanding of the genomic diversity of B. pseudomallei and its genetic near neighbors. Objective: In this review, we discuss a strategy for using comparative genomics to guide the design of inclusivity and exclusivity panels for the validation of assays as defined by the Standard Method Performance Requirement (SMPR). Methods: Based upon a literature review, comparative genomic analyses, and hands-on experience with diagnostic development and testing, we describe important factors to consider when developing inclusivity and exclusivity panels for testing diagnostic and/or detection tools. Results: The genomic diversity of B. pseudomallei is substantial, with the genome characterized by horizontal gene transfer, including the acquisition of genomic islands from near-neighbor species. This genomic diversity, core genome reduction, and signal erosion can complicate molecular diagnostic tool development and validation. Conclusions: Accurate diagnostic and/or detection tools targeting B. pseudomallei, an important pathogen from a public health and biodefense perspective, are needed for many applications. Utilizing whole genome sequencing data and comparative genomic techniques can guide the development and validation of such tools. Amplicon sequencing assays and assay redundancy can provide improved assay performance. Highlights: When developing and validating diagnostic and/or detection tools targeting B. pseudomallei, it is important to consider genomic diversity, genome reduction, and signal erosion to reduce the effects of typical diagnostic errors.
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Técnicas de Tipificación Bacteriana/métodos , Burkholderia pseudomallei/aislamiento & purificación , Técnicas de Genotipaje/métodos , Melioidosis/diagnóstico , Técnicas de Tipificación Bacteriana/normas , Burkholderia mallei/genética , Burkholderia mallei/aislamiento & purificación , Burkholderia pseudomallei/genética , Técnicas de Genotipaje/normas , Muermo/diagnóstico , Muermo/microbiología , Humanos , Límite de Detección , Melioidosis/microbiologíaRESUMEN
We present the first molecular characterisation based on MLVA and SNP analysis of a strain of Burkholderia mallei isolated from a mule found dead in Brazil in 2016.
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Burkholderia mallei/clasificación , Burkholderia mallei/genética , Equidae/microbiología , Muermo/epidemiología , Muermo/microbiología , Animales , Brasil/epidemiología , Burkholderia mallei/aislamiento & purificación , Genoma Bacteriano , Genotipo , Tipificación de Secuencias Multilocus , Filogenia , Polimorfismo de Nucleótido Simple , Secuenciación Completa del GenomaRESUMEN
Burkholderia mallei is the aetiological agent of glanders, a highly contagious and re-emerging zoonotic disease. Early diagnosis of glanders is critically important to ensure timely treatment with appropriate antibiotics in humans, and to prevent spread of infection in animals. Molecular detection of B. mallei has always been troublesome because of its genetic similarity with Burkholderia pseudomallei, the causative agent of melioidosis. In present investigation, a set of six B. mallei-specific primers were designed and a simple, rapid, specific and sensitive real-time loop-mediated isothermal amplification (LAMP) assay was developed for detection of B. mallei. The LAMP assay could detect as low as 1 pg of B. mallei genomic DNA and 5.5 × 103 CFU/ml of B. mallei in spiked human blood. The assay was highly specific for B. mallei as it did not cross-react with other bacterial strains used in the study. The established LAMP assay is field adaptable and can be a better and viable alternative to PCR-based techniques for detection of B. mallei in glanders endemic areas with resource-limited settings.
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Burkholderia mallei/aislamiento & purificación , Muermo/diagnóstico , Técnicas de Amplificación de Ácido Nucleico/veterinaria , Animales , Burkholderia mallei/genética , Burkholderia pseudomallei/genética , Burkholderia pseudomallei/aislamiento & purificación , Cartilla de ADN/genética , Muermo/microbiología , Caballos , Humanos , Melioidosis/microbiología , Melioidosis/veterinaria , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Sensibilidad y Especificidad , ZoonosisRESUMEN
Glanders is a disease of horses, donkeys and mules. The causative agent Burkholderia mallei, is a biorisk group 3 pathogen and is also a biothreat agent. Simple and rapid diagnostic tool is essential for control of glanders. Using a proteomic approach and immunoblotting with equine sera, we identified 12 protein antigens that may have diagnostic potential. Various immunoreactive proteins e.g. GroEL, translation elongation factor Tu, elongation factor Ts, arginine deiminase, malate dehydrogenase, DNA directed RNA polymerase subunit alpha were identified on 2-dimentional immunoblots. One of these proteins, GroEL, was cloned and expressed in E. coli and purified using Ni-NTA affinity chromatography. The recombinant GroEL protein was evaluated in ELISA format on a panel of glanders positive (n=49) and negative (n=79) equine serum samples to determine its diagnostic potential. The developed ELISA had a sensitivity and specificity of 96 and 98.7% respectively. The results of this study highlight the potential of GroEL in serodiagnosis of glanders.
Asunto(s)
Anticuerpos Antibacterianos/sangre , Antígenos Bacterianos/inmunología , Burkholderia mallei/inmunología , Chaperonina 60/inmunología , Muermo/diagnóstico , Enfermedades de los Caballos/diagnóstico , Inmunoproteínas/aislamiento & purificación , Animales , Antígenos Bacterianos/sangre , Antígenos Bacterianos/aislamiento & purificación , Burkholderia mallei/aislamiento & purificación , Chaperonina 60/sangre , Chaperonina 60/genética , Ensayo de Inmunoadsorción Enzimática/métodos , Escherichia coli/genética , Muermo/inmunología , Enfermedades de los Caballos/inmunología , Enfermedades de los Caballos/microbiología , Caballos , Hidrolasas/sangre , Hidrolasas/inmunología , Immunoblotting , Inmunoproteínas/química , Malato Deshidrogenasa/sangre , Malato Deshidrogenasa/inmunología , Factor Tu de Elongación Peptídica/sangre , Factor Tu de Elongación Peptídica/inmunología , Factores de Elongación de Péptidos/sangre , Factores de Elongación de Péptidos/inmunología , Proteómica/métodos , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/aislamiento & purificación , Sensibilidad y Especificidad , Pruebas SerológicasRESUMEN
Burkholderia pseudomallei (Bp) and Burkholderia mallei (Bm), the agents of melioidosis and glanders, respectively, are Tier 1 biothreats. They infect humans and animals, causing disease ranging from acute and fatal to protracted and chronic. Chronic infections are especially challenging to treat, and the identification of in vitro phenotypic markers which signal progression from acute to persistent infection would be extremely valuable. First, a phenotyping strategy was developed employing colony morphotyping, chemical sensitivity testing, macrophage infection, and lipopolysaccharide fingerprint analyses to distinguish Burkholderia strains. Then mouse spleen isolates collected 3-180 days after infection were characterized phenotypically. Isolates from long-term infections often exhibited increased colony morphology differences and altered patterns of antimicrobial sensitivity and macrophage infection. Some of the Bp and Bm persistent infection isolates clearly displayed enhanced virulence in mice. Future studies will evaluate the potential role and significance of these phenotypic markers in signaling the establishment of a chronic infection.
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Burkholderia mallei/aislamiento & purificación , Burkholderia pseudomallei/aislamiento & purificación , Muermo/microbiología , Melioidosis/microbiología , Animales , Burkholderia mallei/patogenicidad , Burkholderia pseudomallei/patogenicidad , Línea Celular , Femenino , Lipopolisacáridos/análisis , Macrófagos/microbiología , Ratones , Ratones Endogámicos BALB C , Fenotipo , Bazo/microbiologíaRESUMEN
The Burkholderia pseudomallei complex classically consisted of B. mallei, B. pseudomallei, and B. thailandensis, but has now expanded to include B. oklahomensis, B. humptydooensis, and three unassigned Burkholderia clades. Methods for detecting and differentiating the B. pseudomallei complex has been the topic of recent research due to phenotypic and genotypic similarities of these species. B. mallei and B. pseudomallei are recognized as CDC Tier 1 select agents, and are the causative agents of glanders and melioidosis, respectively. Although B. thailandensis and B. oklahomensis are generally avirulent, both display similar phenotypic characteristics to that of B. pseudomallei. B. humptydooensis and the Burkholderia clades are genetically similar to the B. pseudomallei complex, and are not associated with disease. Optimal identification of these species remains problematic, and PCR-based methods can resolve issues with B. pseudomallei complex detection and differentiation. Currently, no PCR assay is available that detects the major species of the B. pseudomallei complex. A real-time PCR assay in a multiplex single-tube format was developed to simultaneously detect and differentiate B. mallei, B. pseudomallei, and B. thailandensis, and a common sequence found in B. pseudomallei, B. mallei, B. thailandensis, and B. oklahomensis. A total of 309 Burkholderia isolates and 5 other bacterial species were evaluated. The assay was 100% sensitive and specific, demonstrated sensitivity beyond culture and GC methods for the isolates tested, and is completed in about an hour with a detection limit between 2.6pg and 48.9pg of gDNA. Bioinformatic analyses also showed the assay is likely 100% specific and sensitive for all 84 fully sequenced B. pseudomallei, B. mallei, B. thailandensis, and B. oklahomensis strains currently available in GenBank. For these reasons, this assay could be a rapid and sensitive tool in the detection and differentiation for those species of the B. pseudomallei complex with recognized clinical and practical significance.
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Infecciones por Burkholderia/diagnóstico , Infecciones por Burkholderia/microbiología , Burkholderia/genética , Burkholderia/aislamiento & purificación , Burkholderia mallei/genética , Burkholderia mallei/aislamiento & purificación , Burkholderia pseudomallei/genética , Burkholderia pseudomallei/aislamiento & purificación , ADN Bacteriano/aislamiento & purificación , Muermo/microbiología , Humanos , Melioidosis/microbiología , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Sensibilidad y Especificidad , Análisis de Secuencia de ADN/métodosRESUMEN
The present study was conducted to establish a Loop-mediated isothermal amplification (LAMP) technique for the rapid detection of B. mallei the etiologic agent of glanders, a highly contagious disease of equines. A set of six specific primers targeting integrase gene cluster were designed for the LAMP test. The reaction was optimized using different temperatures and time intervals. The specificity of the assay was evaluated using DNA from B.pseudomallei and Pseudomonas aeruginosa. The LAMP products were analyzed both visually and under UV light after electrophoresis. The optimized conditions were found to be at 63ºC for 60 min. The assay showed high specificity and sensitivity. It was concluded that the established LAMP assay is a rapid, sensitive and practical tool for detection of B. mallei and early diagnosis of glanders.
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Burkholderia mallei/genética , Burkholderia mallei/aislamiento & purificación , Técnicas de Amplificación de Ácido Nucleico/métodos , Animales , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Electroforesis en Gel de Agar , Fluorescencia , Caballos , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
Development of the genotyping methods of glanders agent is urgent due to its high pathogenicity, lack of effective preventive measures and threat of the use of Burkholderia mallei as a biological weapon. In this work we proposed a scheme for the typing of the B. mallei strains based on different region analysis (DFR). The choice of variable loci differentially presented in various strains of glanders agents was performed by analyzing annotated whole-genome sequences of the B. mallei strains. Primers and fluorescence probes were designed for 9 selected loci. The amplification conditions for different regions were optimized in two variants: with electrophoretic detection and hybridization-fluorescence detection in the strip format. The possibility of applying the DFR analysis to genetic characterization of strains was assessed in 14 B. mallei strains. The genetic profiles of the studied B. mallei strains revealed that the developed DFR-typing scheme was characterized by high discrimination power (Hunter-Gaston index value was 0.92), reproducibility, rapidity, easy interpretation, and applicability for epidemiological surveillance of glanders.
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Burkholderia mallei/genética , ADN Bacteriano/genética , Técnicas de Genotipaje , Muermo/genética , Reacción en Cadena de la Polimerasa , Animales , Burkholderia mallei/aislamiento & purificación , Humanos , Federación de RusiaRESUMEN
To evaluate the routine complement fixation test (CFT) used to detect Burkholderia mallei antibodies in equine sera, an interlaboratory proficiency test was held with 24 European laboratories, including 22 National Reference Laboratories for glanders. The panels sent to participants were composed of sera with or without B mallei antibodies. This study confirmed the reliability of CFT and highlighted its intralaboratory reproducibility. However, the sensitivity of glanders serodiagnosis and laboratory proficiency may be improved by standardising critical reagents, including antigens, and by developing a standard B mallei serum.
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Anticuerpos Antibacterianos/sangre , Burkholderia mallei/aislamiento & purificación , Pruebas de Fijación del Complemento/veterinaria , Muermo/diagnóstico , Laboratorios/estadística & datos numéricos , Animales , Burkholderia mallei/inmunología , Europa (Continente) , Femenino , Caballos , Reproducibilidad de los ResultadosRESUMEN
The article presents the results of application of developed methodological approach to identifying Burkholderia pseudomallei and Burkholderia mallei using direct mass spectrometry profiling of cellular proteins. The protocol of sampling preparation of cultures of melioidosis and glanders was optimized with taking in account characteristics of observation of requirements of biological safety for operations with pathogenic biological agents of pathogenicity group II. The dependence of quality of mass spectrums (number of individual peaks and their intensity) from medium of fermentation of microorganisms was evaluated. The characteristic mass spectrums of collection strains B.pseudomallei (5) and B.mallei (5) were obtained. The set of reference mass-spectrums was generated for identification data base S.A.R.A.M.I.S.TM (Anagnostec Gmbh.). The mentioned data base was used for identification of 43 strains of pathogenic Burkholderia. The opportunity of reliable identification of taxonomic belonging of examined microorganisms up to species' level. The cluster analysis of obtained mass-spectrums of common cellular proteins of collection strains of pathogenic Burkholderia demonstrated grouping of examined strains according to their species' belonging. The supplemented data base of mass-spectral characteristics hereinafter will permit applying express-identification of isolates suspicious for belonging to agents of melioidosis and glanders. The updated data base will become a basis for developing schemes of hemotyping of strains of Burkholderia using mass spectrometry technique.
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Proteínas Bacterianas/genética , Muermo/diagnóstico , Melioidosis/diagnóstico , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Animales , Proteínas Bacterianas/aislamiento & purificación , Burkholderia mallei/genética , Burkholderia mallei/aislamiento & purificación , Burkholderia pseudomallei/genética , Burkholderia pseudomallei/aislamiento & purificación , Muermo/microbiología , Caballos/microbiología , Humanos , Melioidosis/microbiología , Microbiología del SueloRESUMEN
BACKGROUND: Burkholderia pseudomallei (Bp) and Burkholderia mallei (Bm) are Gram-negative facultative intracellular pathogens, which are the causative agents of melioidosis and glanders, respectively. Depending on the route of exposure, aerosol or transcutaneous, infection by Bp or Bm can result in an extensive range of disease - from acute to chronic, relapsing illness to fatal septicemia. Both diseases are associated with difficult diagnosis and high fatality rates. About ninety five percent of patients succumb to untreated septicemic infections and the fatality rate is 50 % even when standard antibiotic treatments are administered. RESULTS: The goal of this study is to profile murine macrophage-mediated phenotypic and molecular responses that are characteristic to a collection of Bp, Bm, Burkholderia thailandensis (Bt) and Burkholderia oklahomensis (Bo) strains obtained from humans, animals, environment and geographically diverse locations. Burkholderia spp. (N = 21) were able to invade and replicate in macrophages, albeit to varying degrees. All Bp (N = 9) and four Bm strains were able to induce actin polymerization on the bacterial surface following infection. Several Bp and Bm strains showed reduced ability to induce multinucleated giant cell (MNGC) formation, while Bo and Bp 776 were unable to induce this phenotype. Measurement of host cytokine responses revealed a statistically significant Bm mediated IL-6 and IL-10 production compared to Bp strains. Hierarchical clustering of transcriptional data from 84 mouse cytokines, chemokines and their corresponding receptors identified 29 host genes as indicators of differential responses between the Burkholderia spp. Further validation confirmed Bm mediated Il-1b, Il-10, Tnfrsf1b and Il-36a mRNA expressions were significantly higher when compared to Bp and Bt. CONCLUSIONS: These results characterize the phenotypic and immunological differences in the host innate response to pathogenic and avirulent Burkholderia strains and provide insight into the phenotypic alterations and molecular targets underlying host-Burkholderia interactions.