scholarly journals Comparative Genomic Analysis of the Foodborne Pathogen Burkholderia gladioli pv. cocovenenans Harboring a Bongkrekic Acid Biosynthesis Gene Cluster

2021 ◽  
Vol 12 ◽  
Author(s):  
Zixin Peng ◽  
Tania Dottorini ◽  
Yue Hu ◽  
Menghan Li ◽  
Shaofei Yan ◽  
...  

The environmental bacterium Burkholderia gladioli pv. cocovenenans (B. cocovenenans) has been linked to fatal food poisoning cases in Asia and Africa. Bongkrekic acid (BA), a mitochondrial toxin produced by B. cocovenenans, is thought to be responsible for these outbreaks. While there are over 80 species in the Burkholderia genus, B. cocovenenans is the only pathovar capable of producing BA and causing human death. However, the genomic features of B. gladioli and the evolution of the BA biosynthesis gene cluster, bon, in B. cocovenenans remain elusive. In this study, 239 whole genome sequences (WGSs) of B. gladioli, isolated from 12 countries collected over 100 years, were used to analyze the intra-species genomic diversity and phylogenetic relationships of B. gladioli and to explore the origin and evolution of the bon gene cluster. Our results showed that the genome-wide average nucleotide identity (ANI) values were above 97.29% for pairs of B. gladioli genomes. Thirty-six of the 239 (15.06%) B. gladioli genomes, isolated from corn, rice, fruits, soil, and patients from Asia, Europe, North America, and South America, contained the bon gene cluster and formed three clades within the phylogenetic tree. Pan- and core-genome analysis suggested that the BA biosynthesis genes were recently acquired. Comparative genome analysis of the bon gene cluster showed that complex recombination events contributed to this toxin biosynthesis gene cluster’s evolution and formation. This study suggests that a better understanding of the genomic diversity and evolution of this lethal foodborne pathovar will potentially contribute to B. cocovenenans food poisoning outbreak prevention.

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Cerith Jones ◽  
Gordon Webster ◽  
Alex J. Mullins ◽  
Matthew Jenner ◽  
Matthew J. Bull ◽  
...  

Burkholderia gladioli is a bacterium with a broad ecology spanning disease in humans, animals and plants, but also encompassing multiple beneficial interactions. It is a plant pathogen, a toxin-producing food-poisoning agent, and causes lung infections in people with cystic fibrosis (CF). Contrasting beneficial traits include antifungal production exploited by insects to protect their eggs, plant protective abilities and antibiotic biosynthesis. We explored the genomic diversity and specialized metabolic potential of 206 B. gladioli strains, phylogenomically defining 5 clades. Historical disease pathovars (pv.) B. gladioli pv. allicola and B. gladioli pv. cocovenenans were distinct, while B. gladioli pv. gladioli and B. gladioli pv. agaricicola were indistinguishable; soft-rot disease and CF infection were conserved across all pathovars. Biosynthetic gene clusters (BGCs) for toxoflavin, caryoynencin and enacyloxin were dispersed across B. gladioli , but bongkrekic acid and gladiolin production were clade-specific. Strikingly, 13 % of CF infection strains characterized were bongkrekic acid-positive, uniquely linking this food-poisoning toxin to this aspect of B. gladioli disease. Mapping the population biology and metabolite production of B. gladioli has shed light on its diverse ecology, and by demonstrating that the antibiotic trimethoprim suppresses bongkrekic acid production, a potential therapeutic strategy to minimize poisoning risk in CF has been identified.


2019 ◽  
Vol 82 (10) ◽  
pp. 1650-1654 ◽  
Author(s):  
JINGHUA LI ◽  
LU ZHOU ◽  
CHAOYANG LONG ◽  
LEI FANG ◽  
QIAOCHANG CHEN ◽  
...  

ABSTRACT Bongkrekic acid (BKA) is a tricarboxylic fatty acid that inhibits adenine nucleotide translocase as a kind of mitochondrial toxins. BKA is produced by the bacterium Burkholderia gladioli pathovar cocovenenans. An investigation was performed to determine the source of possible BKA poisoning of a family in H City, Guangdong Province, People's Republic of China, who consumed a commercially produced rice noodle product that was not fermented or noticeably spoiled. Clinical and food samples were tested. BKA concentration was detected by liquid chromatography–tandem mass spectrometry. We isolated and identified the suspicious strains from the rice noodles and performed toxicity determination through an animal experiment. BKA detected in the cases and the dead dog was 2.15 to about 343 μg/kg. The cases and dead dog shared a unique history of food exposure. The BKA in the factory's food samples was 150 and 160 μg/kg. All mice given the BKA extract by gavage died within 24 h. In conclusion, the food poisoning was caused by the high BKA concentration of expired (4 days over the 24-h shelf life) wet rice noodle products, with corn and wheat starch contaminated by B. gladioli cocovenenans. Different from traditional BKA poisoning caused by fermented and spoiled corn or coconut products, there was no noticeable spoilage because of the nonfermentation process and overused sodium dehydroacetate. The risk of BKA in wet rice noodle products and application of antiseptics, such as sodium dehydroacetate, in such food should be quantitatively evaluated to prevent the recurrence of similar events.


2010 ◽  
Vol 55 (3) ◽  
pp. 974-982 ◽  
Author(s):  
Qiulin Wu ◽  
Jingdan Liang ◽  
Shuangjun Lin ◽  
Xiufen Zhou ◽  
Linquan Bai ◽  
...  

ABSTRACTThe pyrrole polyether antibiotic calcimycin (A23187) is a rare ionophore that is specific for divalent cations. It is widely used as a biochemical and pharmacological tool because of its multiple, unique biological effects. Here we report on the cloning, sequencing, and mutational analysis of the 64-kb biosynthetic gene cluster fromStreptomyces chartreusisNRRL 3882. Gene replacements confirmed the identity of the gene cluster, andin silicoanalysis of the DNA sequence revealed 27 potential genes, including 3 genes for the biosynthesis of the α-ketopyrrole moiety, 5 genes that encode modular type I polyketide synthases for the biosynthesis of the spiroketal ring, 4 genes for the biosynthesis of 3-hydroxyanthranilic acid, anN-methyltransferase tailoring gene, a resistance gene, a type II thioesterase gene, 3 regulatory genes, 4 genes with other functions, and 5 genes of unknown function. We propose a pathway for the biosynthesis of calcimycin and assign the genes to the biosynthesis steps. Our findings set the stage for producing much desired calcimycin derivatives using genetic modification instead of chemical synthesis.


2010 ◽  
Vol 76 (21) ◽  
pp. 7343-7347 ◽  
Author(s):  
Changming Zhao ◽  
Tingting Huang ◽  
Wenqing Chen ◽  
Zixin Deng

ABSTRACT Polyoxins consist of 14 structurally variable components which differentiate at three branch sites of the carbon skeleton. Open reading frame (ORF) SAV_4805 of Streptomyces avermitilis, showing similarity to thymine-7-hydroxylase, was proved to enhance the diversity of polyoxins at the C-5 site of the 1-(5′-amino-5′-deoxy-β-d-allofuranuronosyl) pyrimidine moiety.


2012 ◽  
Vol 78 (7) ◽  
pp. 2393-2401 ◽  
Author(s):  
Gaiyun Zhang ◽  
Haibo Zhang ◽  
Sumei Li ◽  
Ji Xiao ◽  
Guangtao Zhang ◽  
...  

ABSTRACTAmicetin, an antibacterial and antiviral agent, belongs to a group of disaccharide nucleoside antibiotics featuring an α-(1→4)-glycoside bond in the disaccharide moiety. In this study, the amicetin biosynthesis gene cluster was cloned fromStreptomyces vinaceusdrappusNRRL 2363 and localized on a 37-kb contiguous DNA region. Heterologous expression of the amicetin biosynthesis gene cluster inStreptomyces lividansTK64 resulted in the production of amicetin and its analogues, thereby confirming the identity of theamigene cluster.In silicosequence analysis revealed that 21 genes were putatively involved in amicetin biosynthesis, including 3 for regulation and transportation, 10 for disaccharide biosynthesis, and 8 for the formation of the amicetin skeleton by the linkage of cytosine,p-aminobenzoic acid (PABA), and the terminal (+)-α-methylserine moieties. The inactivation of the benzoate coenzyme A (benzoate-CoA) ligase geneamiLand theN-acetyltransferase geneamiFled to two mutants that accumulated the same two compounds, cytosamine and 4-acetamido-3-hydroxybenzoic acid. These data indicated that AmiF functioned as an amide synthethase to link cytosine and PABA. The inactivation ofamiR, encoding an acyl-CoA-acyl carrier protein transacylase, resulted in the production of plicacetin and norplicacetin, indicating AmiR to be responsible for attachment of the terminal methylserine moiety to form another amide bond. These findings implicated two alternative strategies for amide bond formation in amicetin biosynthesis.


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