Passive immunization does not provide protection against experimental infection with Mycoplasma haemofelis

Sugiarto, Sarah; Spiri, Andrea M.; Riond, Barbara; Novacco, Marilisa; Oestmann, Angelina; de Miranda, Luisa H. Monteiro; Meli, Marina L.; Boretti, Felicitas S.; Hofmann-Lehmann, Regina; Willi, Barbara

For plasma preparation, whole blood was collected from the donor cats from the jugular vein under shortduration general anesthesia (10 mg/kg ketamine, Narketan ® , Vétoquinol AG, Belp, Switzerland; 0.1 mg/kg midazolam, Dormicum ® , Roche Pharma AG, Reinach, Switzerland); the blood was anti-coagulated with acidcitrate-dextrose (ACD) to a final concentration of 3.5%. Plasma was separated from RBCs by centrifugation at 3000g for 10 min and stored at −80 °C until use. Prior to transfusion, the plasma was thawed, pooled (pool A: plasma from the Mhf-recovered cats HBU2, HBZ2 and HCD2; pool B: plasma from the naïve SPF cats GCN5 and JCR4), and filtered through a 0.22 µm pore-size filter (JET BIOFIL, Madrid, Spain), and 9 mL aliquots were prepared. Before freezing and after thawing and filtration, the plasma was tested in triplicate with a Mhf-specific qPCR assay for the absence of Mhf organisms [12] .