title: Antimicrobial susceptibility testing using high surface-to-volume ratio microchannels.
abstract: This study reports the use of microfluidics, which intrinsically has a large surface-to-volume ratio, toward rapid antimicrobial susceptibility testing at the point of care. By observing the growth of uropathogenic Escherichia coli in gas permeable polymeric microchannels with different dimensions, we demonstrate that the large surface-to-volume ratio of microfluidic systems facilitates rapid growth of bacteria. For microchannels with 250 microm or less in depth, the effective oxygenation can sustain the growth of E. coli to over 10(9) cfu/mL without external agitation or oxygenation, which eliminates the requirement of bulky instrumentation and facilitates rapid bacterial growth for antimicrobial susceptibility testing at the point of care. The applicability of microfluidic rapid antimicrobial susceptibility testing is demonstrated in culture media and in urine with clinical bacterial isolates that have different antimicrobial resistance profiles. The antimicrobial resistance pattern can be determined as rapidly as 2 h compared to days in standard clinical procedures facilitating diagnostics at the point of care.
authors.affiliation: Department of Aerospace and Mechanical Engineering, P.O. Box 210119, University of Arizona, 1703 East Mabel Street, Tucson, Arizona 85721, USA.
authors.forename: Chia Hsiang
authors.initials: CH
authors.lastname: Chen
authors.forename: Yi
authors.initials: Y
authors.lastname: Lu
authors.forename: Mandy L Y
authors.initials: ML
authors.lastname: Sin
authors.forename: Kathleen E
authors.initials: KE
authors.lastname: Mach
authors.forename: Donna D
authors.initials: DD
authors.lastname: Zhang
authors.forename: Vincent
authors.initials: V
authors.lastname: Gau
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Liao
authors.forename: Pak Kin
authors.initials: PK
authors.lastname: Wong
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests / Q000295:instrumentation* / Q000379:methods; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D010100:Oxygen / Q000737:chemistry; D013499:Surface Properties; D014552:Urinary Tract Infections / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D004129:Dimethylpolysiloxanes; C013830:baysilon; D010100:Oxygen