title: Burkholderia paludissp. nov., an Antibiotic-Siderophore Producing NovelBurkholderia cepaciaComplex Species, Isolated from Malaysian Tropical Peat Swamp Soil.
abstract: A novel Gram negative rod-shaped bacterium, designated strain MSh1T, was isolated from Southeast Pahang tropical peat swamp forest soil in Malaysia and characterized using a polyphasic taxonomy approach. The predominant cellular fatty acids (>10.0%) were C16:0(31.7%), C17:0cyclo (26.6%), and C19:0cyclo ω8c (16.1%). The polar lipids detected were phosphatidylglycerol, phosphatidylethanolamine, and diphosphatidylglycerol. The predominant ubiquinone was Q-8. This revealed that strain MSh1Tbelongs to the genusBurkholderia. The type strain MSh1Tcan be differentiated from otherBurkholderia cepaciacomplex (Bcc) species by phylogenetic analysis of 16S rRNA gene sequence, multilocus sequence analysis (MLSA), average nucleotide identity (ANI) and biochemical tests. DNA-DNA relatedness values between strain MSh1Tand closely related type strains were below the 70% threshold value. Based on this polyphasic study of MSh1T, it can be concluded that this strain represents a novel species within the Bcc, for which the nameBurkholderia paludissp. nov. is proposed. The type strain is MSh1T(= DSM 100703T= MCCC 1K01245T). The dichloromethane extract of MSh1Texhibited antimicrobial activity against four Gram positive bacteria (Enterococcus faecalisATCC 29212,E. faecalisATCC 700802,Staphylococcus aureusATCC 29213,S. aureusATCC 700699) and a Gram negative bacteria (Escherichia coliATCC 25922). Further purification work has led to the isolation of Compound 1, pyochelin. Pyochelin demonstrated antimicrobial activity against fourS. aureusstrains and threeE.faecalisstrains with MIC-values of 3.13 μg/ml and 6.26 μg/ml, respectively. SEM analysis showed that the cellular morphology ofE. faecalisATCC 700802 was not affected by pyochelin; suggesting that it might target the intracellular components. Pyochelin, a siderophore with antimicrobial activity might be useful in treating bacterial infections caused byS. aureusandE. faecalis, however further work has to be done.
authors.affiliation: School of Science, Monash University MalaysiaBandar Sunway, Malaysia; Tropical Medicine and Biology Multidisciplinary Platform, Monash University MalaysiaBandar Sunway, Malaysia.
authors.forename: Kuan Shion
authors.initials: KS
authors.lastname: Ong
authors.affiliation: School of Science, Monash University MalaysiaBandar Sunway, Malaysia; Tropical Medicine and Biology Multidisciplinary Platform, Monash University MalaysiaBandar Sunway, Malaysia.
authors.forename: Yoong Kit
authors.initials: YK
authors.lastname: Aw
authors.affiliation: Novel Bacteria and Drug Discovery Research Group, School of Pharmacy, Monash University MalaysiaBandar Sunway, Malaysia; Center of Health Outcomes Research and Therapeutic Safety (Cohorts), School of Pharmaceutical Sciences, University PhayaoPhayao, Thailand.
authors.forename: Learn Han
authors.initials: LH
authors.lastname: Lee
authors.affiliation: School of Science, Monash University MalaysiaBandar Sunway, Malaysia; Tropical Medicine and Biology Multidisciplinary Platform, Monash University MalaysiaBandar Sunway, Malaysia.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Yule
authors.affiliation: School of Science, Monash University Malaysia Bandar Sunway, Malaysia.
authors.forename: Yuen Lin
authors.initials: YL
authors.lastname: Cheow
authors.affiliation: School of Science, Monash University MalaysiaBandar Sunway, Malaysia; Tropical Medicine and Biology Multidisciplinary Platform, Monash University MalaysiaBandar Sunway, Malaysia.
authors.forename: Sui Mae
authors.initials: SM
authors.lastname: Lee
keywords: Burkholderia cepacia complex; antimicrobial; multilocus sequence analysis (MLSA); polyphasic taxonomy; tropical peat swamp forest