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

Bilirubin concentrations significantly increased in both groups during the course of the experiment and peaked at day 49 pi (group A, p F < 0.0001; group B, p F = 0.0036; Additional file 1A). Bilirubin concentrations were lower in group A than in group B at days 0 and 14 pi (p MWU = 0.04) but tended to be higher from day 28 until the end of the experiment, with significance reached at day 91 pi (p MWU = 0.0080; Additional file 1A). The mean bilirubin concentrations in both groups remained within the reference interval (bilirubin concentration <3.5 μmol/L) throughout the study period; bilirubin concentrations exceeding the reference interval were observed in three cats in group A (DHR 1, day 49 pi, JHW1, day 49 pi; JHW5, day 56 pi, bilirubin concentrations, range 4.4-7.7 μmol/L). The total protein concentrations significantly changed over time in groups A (p F < 0.0001) and B (p F = 0.0003; Additional file 1B) and peaked at days 63 and 42 pi, respectively. Higher total protein concentrations were observed in cats in group A compared to cats in group B, with significance reached at days 21, 35 and 49 pi (p MWU = 0.0400; Additional file 1B). When cat JHW3 was excluded from the analyses, total protein concentrations of group A were also higher compared to cats in group B with significance reached at days 3, 21 and 42 pi (P MWU < 0.05). The mean total protein concentrations of both groups remained within the reference interval (total protein, reference interval for 16-30 weeks of age, 33-75 g/L) throughout the study period; total protein concentrations above the reference interval were observed in two cats in group A and one cat in group B (total protein concentrations between 76.2-78.6 g/L). The globulin concentrations significantly increased over time only in group A (p F < 0.0001; Additional file 1C). Compared with cats in group B, cats in group A showed significantly higher globulin concentrations at days 21 and 35 pi (p MWU < 0.05; Additional file 1C).