title: Bacterial Cytological Profiling (BCP) as a Rapid and Accurate Antimicrobial Susceptibility Testing Method for Staphylococcus aureus.
abstract: Successful treatment of bacterial infections requires the timely administration of appropriate antimicrobial therapy. The failure to initiate the correct therapy in a timely fashion results in poor clinical outcomes, longer hospital stays, and higher medical costs. Current approaches to antibiotic susceptibility testing of cultured pathogens have key limitations ranging from long run times to dependence on prior knowledge of genetic mechanisms of resistance. We have developed a rapid antimicrobial susceptibility assay for Staphylococcus aureus based on bacterial cytological profiling (BCP), which uses quantitative fluorescence microscopy to measure antibiotic induced changes in cellular architecture. BCP discriminated between methicillin-susceptible (MSSA) and -resistant (MRSA) clinical isolates of S. aureus (n = 71) within 1-2 h with 100% accuracy. Similarly, BCP correctly distinguished daptomycin susceptible (DS) from daptomycin non-susceptible (DNS) S. aureus strains (n = 20) within 30 min. Among MRSA isolates, BCP further identified two classes of strains that differ in their susceptibility to specific combinations of beta-lactam antibiotics. BCP provides a rapid and flexible alternative to gene-based susceptibility testing methods for S. aureus, and should be readily adaptable to different antibiotics and bacterial species as new mechanisms of resistance or multidrug-resistant pathogens evolve and appear in mainstream clinical practice.
authors.affiliation: Department of Bioengineering, University of California, San Diego La Jolla, CA, USA; Division of Biological Sciences, University of California, San Diego La Jolla, CA, USA.
authors.forename: D T
authors.initials: DT
authors.lastname: Quach
authors.affiliation: Division of Pediatric Pharmacology & Drug Discovery, University of California, San Diego La Jolla, CA, USA.
authors.forename: G
authors.initials: G
authors.lastname: Sakoulas
authors.affiliation: Division of Pediatric Pharmacology & Drug Discovery, University of California, San Diego La Jolla, CA, USA; Skaggs School of Pharmacy and Pharmaceutical Science, University of California, San Diego La Jolla, CA, USA.
authors.forename: V
authors.initials: V
authors.lastname: Nizet
authors.affiliation: Division of Biological Sciences, University of California, San Diego La Jolla, CA, USA.
authors.forename: J
authors.initials: J
authors.lastname: Pogliano
authors.affiliation: Division of Biological Sciences, University of California, San Diego La Jolla, CA, USA.
authors.forename: K
authors.initials: K
authors.lastname: Pogliano
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques / Q000379:methods*; D017576:Daptomycin / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000166:cytology* / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D017576:Daptomycin
keywords: Antibiotic resistance; Multidrug resistant bacteria; Staphylococcus aureus; Susceptibility tests