Autor: |
Ong KS; School of Science, Monash University MalaysiaBandar Sunway, Malaysia; Tropical Medicine and Biology Multidisciplinary Platform, Monash University MalaysiaBandar Sunway, Malaysia., Aw YK; School of Science, Monash University MalaysiaBandar Sunway, Malaysia; Tropical Medicine and Biology Multidisciplinary Platform, Monash University MalaysiaBandar Sunway, Malaysia., Lee LH; 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., Yule CM; School of Science, Monash University MalaysiaBandar Sunway, Malaysia; Tropical Medicine and Biology Multidisciplinary Platform, Monash University MalaysiaBandar Sunway, Malaysia., Cheow YL; School of Science, Monash University Malaysia Bandar Sunway, Malaysia., Lee SM; School of Science, Monash University MalaysiaBandar Sunway, Malaysia; Tropical Medicine and Biology Multidisciplinary Platform, Monash University MalaysiaBandar Sunway, Malaysia. |
Abstrakt: |
A novel Gram negative rod-shaped bacterium, designated strain MSh1 T , 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 C 16:0 (31.7%), C 17:0 cyclo (26.6%), and C 19:0 cyclo ω8c (16.1%). The polar lipids detected were phosphatidylglycerol, phosphatidylethanolamine, and diphosphatidylglycerol. The predominant ubiquinone was Q-8. This revealed that strain MSh1 T belongs to the genus Burkholderia . The type strain MSh1 T can be differentiated from other Burkholderia cepacia complex (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 MSh1 T and closely related type strains were below the 70% threshold value. Based on this polyphasic study of MSh1 T , it can be concluded that this strain represents a novel species within the Bcc, for which the name Burkholderia paludis sp. nov. is proposed. The type strain is MSh1 T (= DSM 100703 T = MCCC 1K01245 T ). The dichloromethane extract of MSh1 T exhibited antimicrobial activity against four Gram positive bacteria ( Enterococcus faecalis ATCC 29212, E. faecalis ATCC 700802, Staphylococcus aureus ATCC 29213, S. aureus ATCC 700699) and a Gram negative bacteria ( Escherichia coli ATCC 25922). Further purification work has led to the isolation of Compound 1, pyochelin. Pyochelin demonstrated antimicrobial activity against four S. aureus strains and three E . faecalis strains with MIC-values of 3.13 μg/ml and 6.26 μg/ml, respectively. SEM analysis showed that the cellular morphology of E. faecalis ATCC 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 by S. aureus and E. faecalis , however further work has to be done. |