title: Real-time optical detection of methicillin-resistant Staphylococcus aureus using lytic phage probes.
abstract: Staphylococcus aureus (S. aureus)-specific bacteriophage was used as a probe for detection of methicillin-resistant S. aureus (MRSA) in aqueous solution using a novel optical method. Biorecognition phage monolayers transferred to glass substrates using Langmuir-Blodgett (LB) technique were exposed individually to MRSA in solution at logarithmic concentrations ranging from 10(6) to 10(9)cfu/ml, and observed for real-time binding using a CytoViva optical light microscope system. Results indicate that LB monolayers possessed high levels of elasticity (K), measuring 22 and 29 mN/m for 10(9) and 10(11)pfu/ml phage concentrations, respectively. Near-instantaneous MRSA-phage binding produced 33+/-5%, 10+/-1%, 1.1+/-0.1%, and 0.09+/-0.01% coverage of the substrate that directly correlated to a decrease in MRSA concentrations of 10(9), 10(8), 10(7), and 10(6)cfu/ml. The exclusive selectivity of phage monolayers was verified with Salmonella enterica subsp. enterica serovar typhimurium (S. typhimurium) and Bacillus subtilis.
authors.affiliation: Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, United States.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Guntupalli
authors.forename: Iryna
authors.initials: I
authors.lastname: Sorokulova
authors.forename: April
authors.initials: A
authors.lastname: Krumnow
authors.forename: Oleg
authors.initials: O
authors.lastname: Pustovyy
authors.forename: Eric
authors.initials: E
authors.lastname: Olsen
authors.forename: Vitaly
authors.initials: V
authors.lastname: Vodyanoy
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D016106:Methicillin Resistance; D008853:Microscopy; D015336:Molecular Probe Techniques; D013204:Staphylococcus Phages / Q000502:physiology*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification*