title: Lack of cross-protection against Mycoplasma haemofelis infection and signs of enhancement in "Candidatus Mycoplasma turicensis"-recovered cats.
abstract: "Mycoplasma haemofelis" and "Candidatus Mycoplasma turicensis" are feline hemoplasmas that induce hemolytic anemia. Protection from homologous re-challenge was recently demonstrated in cats recovered from primary infection. Here, we determined if cats recovered from "Cand. M. turicensis" infection were protected against infections with the more pathogenic M. haemofelis. Ten specified pathogen-free cats were exposed to M. haemofelis. Five of the ten cats had recovered from "Cand. M. turicensis" bacteremia (group A), and five cats were naïve controls (group B). No cross-protection was observed. By contrast, the "Cand. M. turicensis"-recovered cats displayed faster M. haemofelis infection onset (earlier PCR-positive and anemic) than the controls. No "Cand. M. turicensis" was detected in any cat. M. haemofelis shedding was observed in saliva, feces and urine. In both groups, evidence of a Th1 response was observed (high IFN-γ, low IL-4), but IL-10 levels were also high. In group A, total, CD4+ and CD8+ T cells increased within days after M. haemofelis exposure. At times of maximal bacteremia, macrocytic hypochromic anemia, neutropenia, monocytosis and a decrease in leukocyte, eosinophil, and lymphocyte counts and subsets thereof (B- and T-cells, CD4+, CD8+ and CD4+CD25+ cells) were particularly significant in group A. Moreover, an increase in protein concentrations, hypoalbuminemia and a polyclonal hypergammaglobulinemia were observed. Five of ten M. haemofelis-infected cats subsequently cleared bacteremia without antibiotic treatment. In conclusion, the study suggests that a previous hemoplasma infection, even when the cat has ostensibly recovered, may influence subsequent infections, lead to an enhancement phenomenon and other differences in infection kinetics.
authors.affiliation: Clinical Laboratory, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland. julia_b@gmx.ch.|Center for Clinical Studies, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland. julia_b@gmx.ch.
authors.forename: Julia
authors.initials: J
authors.lastname: Baumann
authors.affiliation: Clinical Laboratory, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland. mnovacco@vetclinics.uzh.ch.|Center for Clinical Studies, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland. mnovacco@vetclinics.uzh.ch.
authors.forename: Marilisa
authors.initials: M
authors.lastname: Novacco
authors.affiliation: Clinical Laboratory, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland. bwilli@vetclinics.uzh.ch.|Clinic for Small Animal Internal Medicine, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland. bwilli@vetclinics.uzh.ch.
authors.forename: Barbara
authors.initials: B
authors.lastname: Willi
authors.affiliation: Clinical Laboratory, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland. briond@vetclinics.uzh.ch.
authors.forename: Barbara
authors.initials: B
authors.lastname: Riond
authors.affiliation: Clinical Laboratory, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland. mmeli@vetclinics.uzh.ch.|Center for Clinical Studies, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland. mmeli@vetclinics.uzh.ch.
authors.forename: Marina L
authors.initials: ML
authors.lastname: Meli
authors.affiliation: Clinic for Small Animal Internal Medicine, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland. fboretti@vetclinics.uzh.ch.
authors.forename: Felicitas S
authors.initials: FS
authors.lastname: Boretti
authors.affiliation: Clinical Laboratory, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland. rhofmann@vetclinics.uzh.ch.|Center for Clinical Studies, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland. rhofmann@vetclinics.uzh.ch.
authors.forename: Regina
authors.initials: R
authors.lastname: Hofmann-Lehmann
mesh_terms: D000818:Animals; D057138:Bacterial Shedding; D001774:Blood Chemical Analysis / Q000662:veterinary; D002371:Cat Diseases / Q000276:immunology* / Q000382:microbiology; D002415:Cats; D056738:Cross Protection; D016207:Cytokines / Q000276:immunology; D006403:Hematologic Tests / Q000662:veterinary; D016131:Lymphocyte Subsets / Q000276:immunology / Q000382:microbiology; D008297:Male; D009174:Mycoplasma / Q000502:physiology*; D009175:Mycoplasma Infections / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D013045:Species Specificity
chemical_list: D016207:Cytokines