title: Diffusion and activity of antibiotics against Burkholderia pseudomallei biofilms.
abstract: The diffusion and activity of ceftazidime (CAZ), imipenem (IPM) and trimethoprim/sulfamethoxazole (TMP/SMX) against Burkholderia pseudomallei biofilms were comparatively tested using the high biofilm-producing strain B. pseudomallei 377 and the biofilm-defective mutant B. pseudomallei M6. Biofilms were generated by inoculation of bacteria on polycarbonate membranes placed on the surface of tryptic soy agar plates. The results showed that diffusion of TMP/SMX through B. pseudomallei biofilms was similar for both strains. However, diffusion of CAZ and IPM was significantly faster through strain M6 biofilm in comparison with strain 377 biofilm. The viabilities of strain 377 biofilm were significantly higher than those observed with strain M6 for all antibiotics challenged at 4 h, suggesting that the biofilm-forming capacity may be involved in antibiotic susceptibilities in B. pseudomallei. These results re-emphasise the importance of biofilm for antibiotic resistance in B. pseudomallei.
authors.affiliation: Department of Microbiology and Parasitology, Faculty of Medical Science, Naresuan University, Phitsanulok 65000, Thailand.
authors.forename: Phannarai
authors.initials: P
authors.lastname: Pibalpakdee
authors.forename: Surasakdi
authors.initials: S
authors.lastname: Wongratanacheewin
authors.forename: Suwimol
authors.initials: S
authors.lastname: Taweechaisupapong
authors.forename: Pannika R
authors.initials: PR
authors.lastname: Niumsup
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology*; D018441:Biofilms; D001692:Biological Transport; D016957:Burkholderia pseudomallei / Q000187:drug effects* / Q000502:physiology; D002442:Ceftazidime / Q000378:metabolism / Q000494:pharmacology; D004058:Diffusion; D024901:Drug Resistance, Multiple, Bacterial; D015378:Imipenem / Q000378:metabolism / Q000494:pharmacology; D008826:Microbial Sensitivity Tests / Q000379:methods; D050296:Microbial Viability; D010933:Plankton / Q000187:drug effects / Q000502:physiology; D011076:Polycarboxylate Cement / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D011076:Polycarboxylate Cement; C005506:polycarbonate; D015378:Imipenem; D002442:Ceftazidime