title: Automated image analysis for quantification of filamentous bacteria.
abstract: BACKGROUND
  Antibiotics of the β-lactam group are able to alter the shape of the bacterial cell wall, e.g. filamentation or a spheroplast formation. Early determination of antimicrobial susceptibility may be complicated by filamentation of bacteria as this can be falsely interpreted as growth in systems relying on colorimetry or turbidometry (such as Vitek-2, Phoenix, MicroScan WalkAway). The objective was to examine an automated image analysis algorithm for quantification of filamentous bacteria using the 3D digital microscopy imaging system, oCelloScope.
  
  
  RESULTS
  Three E. coli strains displaying different resistant profiles and differences in filamentation kinetics were used to study a novel image analysis algorithm to quantify length of bacteria and bacterial filamentation. A total of 12 β-lactam antibiotics or β-lactam-β-lactamase inhibitor combinations were analyzed for their ability to induce filamentation. Filamentation peaked at approximately 120 min with an average cell length of 30 μm.
  
  
  CONCLUSIONS
  The automated image analysis algorithm showed a clear ability to rapidly detect and quantify β-lactam-induced filamentation in E. coli. This rapid determination of β-lactam-mediated morphological alterations may facilitate future development of fast and accurate AST systems, which in turn will enable early targeted antimicrobial therapy. Therefore, rapid detection of β-lactam-mediated morphological changes may have important clinical implications.
authors.affiliation: Department of Animal Science, Faculty of Science and Technology, Aarhus University, Blichers Allé 20, 8830, Tjele, Denmark. Marlene.Fredborg@anis.au.dk.|Department of Clinical Microbiology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200, Aarhus, Denmark. Marlene.Fredborg@anis.au.dk.
authors.forename: Marlene
authors.initials: M
authors.lastname: Fredborg
authors.affiliation: Department of Clinical Microbiology, Vejle Hospital, Kabbeltoft 25, 7100, Vejle, Denmark. Flemming.rosenvinge@rsyd.dk.
authors.forename: Flemming S
authors.initials: FS
authors.lastname: Rosenvinge
authors.affiliation: Philips BioCell, Gydevang 42, 3450, Allerød, Denmark. erik.spillum@philips.com.
authors.forename: Erik
authors.initials: E
authors.lastname: Spillum
authors.affiliation: Philips BioCell, Gydevang 42, 3450, Allerød, Denmark. stine.kroghsbo@philips.com.
authors.forename: Stine
authors.initials: S
authors.lastname: Kroghsbo
authors.affiliation: Department of Clinical Microbiology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200, Aarhus, Denmark. mikala.wang@skejby.rm.dk.
authors.forename: Mikala
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, 9000, Aalborg, Denmark. tes@bio.aau.dk.
authors.forename: Teis E
authors.initials: TE
authors.lastname: Sondergaard
mesh_terms: D000465:Algorithms; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001331:Automation; D004926:Escherichia coli / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008826:Microbial Sensitivity Tests; D047090:beta-Lactams / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams