Genotyping of Burkholderia mallei from an Outbreak of Glanders in Bahrain Suggests Multiple Introduction Events

Abstract

BackgroundGlanders, caused by the gram-negative bacterium Burkholderia mallei, is a highly infectious zoonotic disease of solipeds causing severe disease in animals and men. Although eradicated from many Western countries, it recently emerged in Asia, the Middle-East, Africa, and South America. Due to its rareness, little is known about outbreak dynamics of the disease and its epidemiology.Methodology/Principal FindingsWe investigated a recent outbreak of glanders in Bahrain by applying high resolution genotyping (multiple locus variable number of tandem repeats, MLVA) and comparative whole genome sequencing to B. mallei isolated from infected horses and a camel. These results were compared to samples obtained from an outbreak in the United Arab Emirates in 2004, and further placed into a broader phylogeographic context based on previously published B. mallei data. The samples from the outbreak in Bahrain separated into two distinct clusters, suggesting a complex epidemiological background and evidence for the involvement of multiple B. mallei strains. Additionally, the samples from Bahrain were more closely related to B. mallei isolated from horses in the United Arab Emirates in 2004 than other B. mallei which is suggestive of repeated importation to the region from similar geographic sources.Conclusion/SignificanceHigh-resolution genotyping and comparative whole genome analysis revealed the same phylogenetic patterns among our samples. The close relationship of the Dubai/UAE B. mallei populations to each other may be indicative of a similar geographic origin that has yet to be identified for the infecting strains. The recent emergence of glanders in combination with worldwide horse trading might pose a new risk for human infections.

Genome-Wide RNA Sequencing Analysis of Quorum Sensing-Controlled Regulons in the Plant-Associated Burkholderia glumae PG1 Strain

“…These studies analyzed the QS-dependent expression profiles in Burkholderia cenocepacia (27), B. thailandensis (28), Burkholderia gladioli (29), and B. mallei and B. pseudomallei (30). While B. thailandensis is a nonpathogenic tropical soil microorganism, B. cenocepacia, B. mallei, and B. pseudomallei are considered human and animal pathogens (31)(32)(33). Interestingly, the B. thailandensis and B. pseudomallei strains that have been analyzed were found to harbor three AHL-based systems, while the genome of the B. mallei isolate analyzed codes only for two AHL synthases.…”

Development of a rapid and sensitive recombinase polymerase amplification‐lateral flow assay for detection ofBurkholderia mallei

“…Molecular methods viz. randomly amplified polymorphic DNA (RAPD), MLST, BurkDiff, pulse‐field gel electrophoresis, multiple locus variable number of tandem repeats, MLVA and one gene pyrosequencing have also been developed for identification and differentiation of B. mallei and B. pseudomallei (Antonov et al., ; Bowers et al., ; Chantratita et al., ; Gilling, Luna, & Pflugradt, ; Scholz et al., ). Polymerase chain reaction and other molecular assays are laboratory based, time consuming, labour intensive and require complicated instrumentation and technical expertise.…”

Development of a real-time loop-mediated isothermal amplification assay for detection ofBurkholderia mallei

“…In year 2006, A PCR assay and a 5ʹ nuclease real‐time PCR test targeting flagellar biosynthesis protein‐insertion sequence ( fliP‐ IS 407 A) were reported for specific and direct identification of B. mallei (Scholz et al., ; Tomaso et al., ). Other molecular methods for identification and differentiation of B. mallei from B. pseudomallei include pulse‐field gel electrophoresis, 16S rRNA sequencing, MLVA, PCR‐restriction fragment length polymorphism, randomly amplified polymorphic DNA (RAPD), MLST, BurkDiff and one gene pyrosequencing (Antonov et al., , ; Bowers et al., ; Chantratita et al., ; Gilling, Luna, & Pflugradt, ; Harvey & Minter, ; Scholz et al., ; Tanpiboonsak, Paemanee, Bunyarataphan, & Tungpradabkul, ). The described molecular methods are expensive, time‐consuming and labour intensive and require technical expertise, making them non‐viable for many laboratories with resource‐poor settings.…”