Sequence-based detection and typing procedures for Burkholderia mallei: Assessment and prospects

Abstract

Although glanders has been eradicated in most of the developed world, the disease still persists in various countries such as Brazil, India, Pakistan, Bangladesh, Nepal, Iran, Bahrain, UAE and Turkey. It is one of the notifiable diseases listed by the World Organization for Animal Health. Occurrence of glanders imposes restriction on equestrian events and restricts equine movement, thus causing economic losses to equine industry. The genetic diversity and global distribution of the causing agent, Burkholderia (B.) mallei, have not been assessed in detail and are complicated by the high clonality of this organism. Among the identification and typing methods, PCR-based methods for distinguishing B. mallei from its close relative B. pseudomallei as well as genotyping using tandem repeat regions (MLVA) are established. The advent and continuous advancement of the sequencing techniques and the reconstruction of closed genomes enable the development of genome guided epidemiological tools. For achieving a higher genomic resolution, genotyping methods based on whole genome sequencing data can be employed, like genome-wide single nucleotide polymorphisms. One of the limitations in obtaining complete genomic sequences for further molecular characterization of B. mallei is its high GC content. In this review, we aim to provide an overview of the widely used detection and typing methods for B. mallei and illustrate gaps that still require development. The genomic features of Burkholderia, their high homology and clonality will be first described from a comparative genomics perspective. Then, the commonly used molecular detection (PCR systems) and typing systems (e.g., multilocus sequence typing, variable number of tandem repeat analysis) will be presented and put in perspective with recently developed genomic methods. Also, the increasing availability of B. mallei genomic sequences and evolution of the sequencing methods offers exciting prospects for further refinement of B. mallei typing, that could overcome the difficulties presently encountered with this particular bacterium.

Influence of genomic variations on glanders serodiagnostic antigens using integrative genomic and transcriptomic approaches

“…Other Chinese isolates, such as strain China 5 and ATCC 10399, were found in L5. Interestingly, strains FDAARGOS_587, 2000031063, and KC_1092 were also clustered in L5, an observation which is consistent with previous publications that have pointed out inaccurate metadata for these isolates ( 15 , 54 , 55 ). The majority of isolates from Turkey were grouped into L2.…”

Glanders Diagnosis in an Asymptomatic Mare from Brazil: Insights from Serology, Microbiological Culture, Mass Spectrometry, and Genome Sequencing

“…The fliP pseudogene is described as incomplete, which agrees with a potential disruption caused by an insertion sequence. The genome size can also be used to distinguish B. mallei from B. pseudomallei; B. mallei has a smaller genome size than B. pseudomallei (~7.2 Mb) [32]. Accordingly, B. mallei BAC 86/19 showed an estimated genome size of 5.51 Mb, which is in accordance with other B. mallei strains and smaller than that of B. pseudomallei [32].…”

“…The differentiation of B. mallei from B. pseudomallei has been historically difficult due to their high genomic similarity [32]. A major phenotypic difference between the two species is motility.…”

“…The N50 of scaffolds was found to be 3,324,748 bp, with 2019 spanned gaps and a total ungapped length of 5,305,955 bp. The presence of repetitive sequences in the B. mallei genome has been known to result in a substantial number of contigs during genome assembly using short reads [32]. The estimated genome size was 5,507,851 bp.…”

Practice of standardization of CLSI M45 A3 antimicrobial susceptibility testing of Infrequently Isolated or Fastidious Bacteria strains isolated from blood specimens in Guangdong Province 2017–2021

“…The report by Limmathurotsakul et al showed that diabetes is an important risk factor for Burkholderia pseudomallei infection. The report by Syed et al pointed out that the prevalence of Burkholderia pseudomallei infection is increasing ( Limmathurotsakul et al, 2016 ; Syed and Wooten, 2021 ; Brangsch et al, 2022 ). Brucella spp.…”