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Chronic "Candidatus Mycoplasma turicensis" infection.

Novacco M, Boretti FS, Wolf-Jäckel GA, Riond B, Meli ML, Willi B, Lutz H, Hofmann-Lehmann R - Vet. Res. (2011)

Bottom Line: The pathogenesis of "Candidatus M. turicensis" chronic infection is poorly understood.All other samples tested PCR-negative.Methylprednisolone administration did not lead to a significant reactivation of the infection.

View Article: PubMed Central - HTML - PubMed

Affiliation: Clinical Laboratory, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland. mnovacco@vetclinics.uzh.ch.

ABSTRACT
"Candidatus Mycoplasma turicensis" infects felids. The pathogenesis of "Candidatus M. turicensis" chronic infection is poorly understood. The goals of the present study were to (1) induce reactivation of the infection in chronic carrier cats by attempted immunosuppression, (2) identify potential tissue sequestration using real-time TaqMan® PCR and (3) monitor the humoral immune response by DnaK enzyme-linked immunosorbent assay (ELISA). Ten specified pathogen-free cats that had ostensibly recovered from experimental "Candidatus M. turicensis" infection were used: five cats (group 1) received high dose methylprednisolone (attempted immunosuppression), while five cats served as untreated controls (group 2). Besides weekly blood samples, tissue samples were collected from bone marrow, kidney, liver and salivary glands at selected time points. The cats in group 1 had significantly lower lymphocyte counts and higher blood glucose levels after methylprednisolone administration than the controls. After methylprednisolone administration one blood and three tissue samples from cats in group 1 tested PCR-positive; before the administration, only one sample was positive. All other samples tested PCR-negative. All cats stayed seropositive; the antibody levels of the cats in group 1 showed a significant transient decrease after methylprednisolone administration. This is the first study to report the presence of "Candidatus M. turicensis" in tissues of chronically infected cats and the persistence of anti-feline hemoplasma antibodies in the absence of detectable bacteremia. Methylprednisolone administration did not lead to a significant reactivation of the infection. Our results enhance the knowledge of "Candidatus M. turicensis" infection pathogenesis and are clinically relevant to the prognosis of hemoplasma-infected cats.

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Antibody levels to DnaK depicted as ELISA signal-to-noise ratio. A) Cats in group 1; methylprednisolone administration (black arrows); B) cats in the untreated control group 2.
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Figure 2: Antibody levels to DnaK depicted as ELISA signal-to-noise ratio. A) Cats in group 1; methylprednisolone administration (black arrows); B) cats in the untreated control group 2.

Mentions: All cats were seropositive at the start of the study (ELISA signal-to-noise ratio ≥1.5). Six cats had high antibody levels (ELISA signal-to-noise ratio >6), three cats had intermediate levels (ELISA signal-to-noise ratio between 2 and 4) and one cat had low antibody levels (ELISA signal-to-noise ratio <2) (Figure 2). There was no significant difference between the antibody levels of groups 1 and 2 at the beginning of the present study. A significant decrease in antibody levels (PFriedman= 0.0018) was observed throughout methylprednisolone administration (from day 0 to 16) in group 1. This decrease was followed by a significant increase (from day 16 to 35, PFriedman = 0.0452), which returned the antibody levels to approximately pretreatment levels (Figure 2A). In the untreated control group, no significant changes in the antibody levels were found during these periods (Figure 2B). Moreover, no significant differences in the antibody levels were observed between groups 1 and 2 at any of the time points tested (17 blood collections throughout the observation period); however, a trend towards difference was found at day 20 when the cats in group 1 had slightly lower antibody levels than the cats in group 2 (PMWU = 0.0952). In addition, when the antibody levels from all ten cats were compared between day 0 and the end of the project (day 154), we found a trend toward a decrease (PWilcoxon = 0.0840). In contrast, in cat S1, which was the only cat that was transiently blood PCR-positive, we found an increase in the antibody levels from day 35 until the end of the experiment, and the antibody level was higher at the end of the experiment than it was at the beginning.


Chronic "Candidatus Mycoplasma turicensis" infection.

Novacco M, Boretti FS, Wolf-Jäckel GA, Riond B, Meli ML, Willi B, Lutz H, Hofmann-Lehmann R - Vet. Res. (2011)

Antibody levels to DnaK depicted as ELISA signal-to-noise ratio. A) Cats in group 1; methylprednisolone administration (black arrows); B) cats in the untreated control group 2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3090992&req=5

Figure 2: Antibody levels to DnaK depicted as ELISA signal-to-noise ratio. A) Cats in group 1; methylprednisolone administration (black arrows); B) cats in the untreated control group 2.
Mentions: All cats were seropositive at the start of the study (ELISA signal-to-noise ratio ≥1.5). Six cats had high antibody levels (ELISA signal-to-noise ratio >6), three cats had intermediate levels (ELISA signal-to-noise ratio between 2 and 4) and one cat had low antibody levels (ELISA signal-to-noise ratio <2) (Figure 2). There was no significant difference between the antibody levels of groups 1 and 2 at the beginning of the present study. A significant decrease in antibody levels (PFriedman= 0.0018) was observed throughout methylprednisolone administration (from day 0 to 16) in group 1. This decrease was followed by a significant increase (from day 16 to 35, PFriedman = 0.0452), which returned the antibody levels to approximately pretreatment levels (Figure 2A). In the untreated control group, no significant changes in the antibody levels were found during these periods (Figure 2B). Moreover, no significant differences in the antibody levels were observed between groups 1 and 2 at any of the time points tested (17 blood collections throughout the observation period); however, a trend towards difference was found at day 20 when the cats in group 1 had slightly lower antibody levels than the cats in group 2 (PMWU = 0.0952). In addition, when the antibody levels from all ten cats were compared between day 0 and the end of the project (day 154), we found a trend toward a decrease (PWilcoxon = 0.0840). In contrast, in cat S1, which was the only cat that was transiently blood PCR-positive, we found an increase in the antibody levels from day 35 until the end of the experiment, and the antibody level was higher at the end of the experiment than it was at the beginning.

Bottom Line: The pathogenesis of "Candidatus M. turicensis" chronic infection is poorly understood.All other samples tested PCR-negative.Methylprednisolone administration did not lead to a significant reactivation of the infection.

View Article: PubMed Central - HTML - PubMed

Affiliation: Clinical Laboratory, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland. mnovacco@vetclinics.uzh.ch.

ABSTRACT
"Candidatus Mycoplasma turicensis" infects felids. The pathogenesis of "Candidatus M. turicensis" chronic infection is poorly understood. The goals of the present study were to (1) induce reactivation of the infection in chronic carrier cats by attempted immunosuppression, (2) identify potential tissue sequestration using real-time TaqMan® PCR and (3) monitor the humoral immune response by DnaK enzyme-linked immunosorbent assay (ELISA). Ten specified pathogen-free cats that had ostensibly recovered from experimental "Candidatus M. turicensis" infection were used: five cats (group 1) received high dose methylprednisolone (attempted immunosuppression), while five cats served as untreated controls (group 2). Besides weekly blood samples, tissue samples were collected from bone marrow, kidney, liver and salivary glands at selected time points. The cats in group 1 had significantly lower lymphocyte counts and higher blood glucose levels after methylprednisolone administration than the controls. After methylprednisolone administration one blood and three tissue samples from cats in group 1 tested PCR-positive; before the administration, only one sample was positive. All other samples tested PCR-negative. All cats stayed seropositive; the antibody levels of the cats in group 1 showed a significant transient decrease after methylprednisolone administration. This is the first study to report the presence of "Candidatus M. turicensis" in tissues of chronically infected cats and the persistence of anti-feline hemoplasma antibodies in the absence of detectable bacteremia. Methylprednisolone administration did not lead to a significant reactivation of the infection. Our results enhance the knowledge of "Candidatus M. turicensis" infection pathogenesis and are clinically relevant to the prognosis of hemoplasma-infected cats.

Show MeSH
Related in: MedlinePlus