SA/MRSA isolates used in these studies.

<p>Isolates were confirmed as SA or MRSA as detailed in Methods. Methicillin resistance was tested by growth on MSA plates in the presence of 2μg/mL oxacillin. ATCC = American Type Culture Collection, NS = human nasal swab, HA = hospital acquired, DH = dog hair, CJ = raw chicken, RB = raw beef, TK = raw turkey.</p><p>SA/MRSA isolates used in these studies.</p

Decontamination of lab coats and glass coverslips.

<p>MRSA samples were inoculated onto either lab coat fabric or glass coverslips and then exposed to either a single phage or a mock phage treatment (sterile phage buffer only). The MOI ranged from 50 to 20,000. Bacteria were recovered and viable bacterial counts were determined by serial dilution and growth on LB agar plates. Results are reported as colony-forming units ml^-1 A) MRSA strain M1 treated with either SEW, M1M4, CJ11 or CJ12 recovered from lab coat fabric. B) MRSA strain M1 treated with either SEW, M1M4, CJ11 or CJ12 recovered from glass coverslips. C) MRSA strain DH1 treated with either SEW, M1M4, CJ11 or CJ12 recovered from lab coat fabric. D) MRSA strain DH1 treated with either SEW, M1M4, CJ11, or CJ12 recovered from glass coverslips. Assays were performed in triplicate; standard error is indicated. * p ≤ 0.05 by unpaired, one-tailed student’s t test when evaluating phage-treated vs mock-treated samples. # p ≤ 0.005 by same student’s t test.</p

Decontamination of lab coats and glass coverslips with a phage cocktail.

<p>MRSA samples were inoculated onto either lab coat fabric or glass coverslips and then exposed to a phage cocktail consisting of SEW, M1M4, CJ11, CJ12, or mock phage treatment (sterile phage buffer only). The combined MOI ranged from 300 to 1,300. Bacteria were recovered from treated materials and viable bacterial counts were determined by serial dilution and growth on LB agar plates. A) MRSA strain M1 and DH1 treated with phage cocktail or mock treatment recovered from lab coat fabric. B) MRSA strain M1 and DH1 treated with phage cocktail or mock treatment recovered from glass coverslips. Assays were performed in triplicate; standard error is indicated. * p ≤ 0.05 by unpaired, one-tailed student’s t test when evaluating phage-treated vs mock-treated samples. # p ≤ 0.005 by same student’s t test.</p

Assessment of host range by spot testing.

<p>Following plaque purification, phages were tested for host range by spot testing on lawns of SA and MRSA isolates. Detection of any lawn clearing is indicated by an X. All testing was performed in triplicate, and virus stocks were serially diluted to confirm presence of phage lysis (discreet plaque formation) rather than bacteriocin activity.</p><p>Assessment of host range by spot testing.</p

Assessment of host range by lysis of bacterial cultures.

<p>Phage were added to log phase bacterial cultures to assess host range and to determine the killing efficiency of the phages. Optical density was measured at 600nm to quantify cell density of the culture. A) MRSA strain DH1 infected with phage strain SEW across a time course. B) MRSA strain DH1 infected with phage strain CJ11 across a time course. C) A variety of bacterial strains were challenged with different phage and OD₆₀₀ readings were taken at 4h. Results are reported in ΔOD₆₀₀ units which were calculated as the difference between the OD₆₀₀ of mock-treated cultures (sterile phage buffer only) and phage-treated cultures. D) Various combinations of bacterial strains were treated with either single phage strains or combinations phage. In panels C and D, the percent difference in OD₆₀₀ readings (phage-treated divided by mock-treated) is also shown. All experiments were performed in triplicate; standard error is indicated. * p ≤ 0.002 by student’s t test. # p ≤ 0.01 by student’s t test when evaluating phage treated vs mock treated samples.</p