Unfortunately, the antibiotic treatment was not effective so the patient was subsequently subjected to successful phage therapy. This is a typical S. aureus strain producing beta-hemolysin.

The lethal dose of this strain for CBA mice pretreated with 350 mg/kg b.w. of CP was 4 × 108 (LD100). Both S. aureus strain and S. aureus A5/L bacteriophages are deposited in the Bacteriophage CX-6258 mw Laboratory of the Institute of Immunology and Experimental Therapy, Wrocław. The preparation and purification of specific bacteriophages were described by us elsewhere [30]. LPS contamination of the phage preparation was negligible as determined by Limulus amebocyte lysate (LAL) (1.8 E.U. per 106 phages). Cyclophosphamide (CP) was from ASTA Medica, Frankfurt, Germany. Treatment of mice with cyclophosphamide,

4SC-202 in vitro S. aureus and bacteriophages Mice were injected with CP (200 or 350 mg/kg b.w.) intraperitoneally (i.p.) as indicated in the figure legends. Bacteria were administered intravenously (i.v.), into lateral tail vein, four days after CP, at a dose of 5 × 106/mouse. Bacterial cell numbers were determined colorimetrically at a wavelength of 600 nm according to previously prepared standards. Virulent S. aureus A5/L bacteriophages were administered i.p. 30 minutes before infection, at a dose of 1 × 106/mouse. Control mice received 0.2 ml of 0.9% NaCl instead of bacteria and phages. In some experimental protocols control mice were given phages or bacteria only. Determination of S. aureus in the organs Twenty four hours after infection, the mice were sacrificed, the organs (spleens, livers and kidneys) were https://www.selleckchem.com/products/prt062607-p505-15-hcl.html isolated and homogenized using a plastic syringe piston and a plastic screen, in sterile PBS (1 g of wet tissue per 25 ml of PBS). Five- and fifty-fold dilutions of cell suspension were applied onto Chapmann agar plates and incubated overnight and the colony-forming

units (CFU) were enumerated. The number of colonies was expressed as the number of CFU per milligram of the organ. Analysis of cell types in the circulating blood and bone marrow Samples of blood were taken on day 0, just before administration 4-Aminobutyrate aminotransferase of CP, 4 days after administration of CP, just before administration of phages and bacteria (day 4) and at 24 h following infection (day 5). The bone marrow was isolated on days 0 and 5. Blood and bone marrow smears were prepared and stained with May-Grünwald and Giemsa reagents. The preparations were reviewed microscopically by a histologist at 1000× magnification. Determination of serum TNF-α and IL-6 levels The activities of TNF-α and IL-6 in sera were determined by bioassays using WEHI 164.13 and 7TD1 cell lines, respectively [31, 32]. Determination of serum antibody titer to S. aureus and sheep red blood cells (SRBC) Mice were given CP (200 mg/kg b.w.). After four days the mice were infected i.v. with S. aureus at a dose of 5 × 106/mouse and administered i.p.