Mycoplasma haemofelis

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Regina Hofmann-lehmann - One of the best experts on this subject based on the ideXlab platform.

  • Consecutive antibiotic treatment with doxycycline and marbofloxacin clears bacteremia in Mycoplasma haemofelis-infected cats.
    Veterinary microbiology, 2018
    Co-Authors: Marilisa Novacco, Sarah Sugiarto, Andrea M. Spiri, Barbara Willi, Barbara Riond, Felicitas S. Boretti, Angelina Oestmann, Julia Baumann, Hanspeter Naegeli, Regina Hofmann-lehmann
    Abstract:

    Mycoplasma haemofelis is the most pathogenic feline hemoplasma species and a causative agent of infectious hemolytic anemia in cats. Current treatment protocols are effective in reducing M. haemofelis blood loads and clinical signs but consistent bacteremia clearance is rarely achieved. The aim of this study was to develop an antibiotic treatment protocol capable of clearing M. haemofelis bacteremia. Doxycycline and marbofloxacin treatment protocols were evaluated in chronically M. haemofelis infected cats in two pre-experiments and a controlled treatment study (main experiment) using five treated and four untreated cats. The blood bacterial loads in the main experiment were monitored weekly by real-time PCR for 203 days. Cats were treated with doxycycline (5 mg/kg bid orally) for 28 days. Cats that remained M. haemofelis PCR-positive or became positive again (all 5 cats in the main experiment) were switched to marbofloxacin treatment (2 mg/kg sid orally) for 14 days; then, all cats were PCR-negative. Immunosuppression after the antibiotic treatment did not lead to reactivation of bacteremia. Fine needle aspirates of different organs and bone marrow collected before and after immunosuppression were PCR-negative. Overall, 5 cats cleared bacteremia with doxycycline alone (showing lower bacterial loads at the treatment start), while 10 cats needed to be switched to marbofloxacin. Based on our results, we recommend doxycycline treatment (10 mg/kg up to 28 days) for clearance of M. haemofelis infection and monitoring bacterial loads by real-time PCR. Only if bacteremia persists or reoccurs, antibiotic treatment should be switched to marbofloxacin (2 mg/kg sid for 14 days).

  • Passive immunization does not provide protection against experimental infection with Mycoplasma haemofelis
    Veterinary Research, 2016
    Co-Authors: Sarah Sugiarto, Andrea M. Spiri, Luisa H.monteiro De Miranda, Barbara Riond, Regina Hofmann-lehmann, Felicitas S. Boretti, Marina L Meli, Marilisa Novacco, Angelina Oestmann, Barbara Willi
    Abstract:

    Mycoplasma haemofelis (Mhf) is the most pathogenic feline hemotropic Mycoplasma. Cats infected with Mhf that clear bacteremia are protected from Mhf reinfection, but the mechanisms of protective immunity are unresolved. In the present study we investigated whether the passive transfer of antibodies from Mhf-recovered cats to naïve recipient cats provided protection against bacteremia and clinical disease following homologous challenge with Mhf; moreover, we characterized the immune response in the recipient cats. Ten specified pathogen-free (SPF) cats were transfused with pooled plasma from cats that had cleared Mhf bacteremia; five control cats received plasma from naïve SPF cats. After homologous challenge with Mhf, cats were monitored for 100 days using quantitative PCR, hematology, blood biochemistry, Coombs testing, flow cytometry, DnaK ELISA, and red blood cell (RBC) osmotic fragility (OF) measurement. Passively immunized cats were not protected against Mhf infection but, compared to control cats, showed significantly higher RBC OF and B lymphocyte (CD45R/B220(+)) counts and occasionally higher lymphocyte, monocyte and activated CD4(+) T lymphocyte (CD4(+)CD25(+)) counts; they also showed higher bilirubin, total protein and globulin levels compared to those of control cats. At times of peak bacteremia, a decrease in eosinophils and lymphocytes, as well as subsets thereof (B lymphocytes and CD5(+), CD4(+) and CD8(+) T lymphocytes), and an increase in monocytes were particularly significant in the passively immunized cats. In conclusion, passive immunization does not prevent bacteremia and clinical disease following homologous challenge with Mhf, but enhances RBC osmotic fragility and induces a pronounced immune response.

  • Lack of cross-protection against Mycoplasma haemofelis infection and signs of enhancement in “Candidatus Mycoplasma turicensis”-recovered cats
    Veterinary Research, 2015
    Co-Authors: Julia Baumann, Barbara Willi, Barbara Riond, Felicitas S. Boretti, Marina L Meli, Marilisa Novacco, Regina Hofmann-lehmann
    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.

  • Protective immunity against infection with Mycoplasma haemofelis
    Clinical and Vaccine Immunology, 2015
    Co-Authors: Chelsea A.e. Hicks, Barbara Willi, Christopher R Helps, Barbara Riond, Regina Hofmann-lehmann, Christopher R. Stokes, Marina L Meli, Marilisa Novacco, Sybil Tasker
    Abstract:

    Hemoplasmas are potentially zoonotic Mycoplasmal pathogens, which are not consistently cleared by antibiotic therapy. Mycoplasma haemofelis is the most pathogenic feline hemoplasma species. The aim of this study was to determine how cats previously infected with M. haemofelis that had recovered reacted when rechallenged with M. haemofelis and to characterize the immune response following de novo M. haemofelis infection and rechallenge. Five specific-pathogen-free (SPF)-derived naive cats (group A) and five cats that had recovered from M. haemofelis infection (group B) were inoculated subcutaneously with M. haemofelis. Blood M. haemofelis loads were measured by quantitative PCR (qPCR), antibody response to heat shock protein 70 (DnaK) by enzyme-linked immunosorbent assay (ELISA), blood lymphocyte cell subtypes by flow cytometry, and cytokine mRNA levels by quantitative reverse transcriptase PCR. Group A cats all became infected with high bacterial loads and seroconverted, while group B cats were protected from reinfection, thus providing the unique opportunity to study the immunological parameters associated with this protective immune response against M. haemofelis. First, a strong humoral response to DnaK was only observed in group A, demonstrating that an antibody response to DnaK is not important for protective immunity. Second, proinflammatory cytokine interleukin-6 (IL-6) mRNA levels appeared to increase rapidly postinoculation in group B, indicating a possible role in protective immunity. Third, an increase in IL-12p35 and -p40 mRNA and decrease in the Th2/Th1 ratio observed in group A suggest that a Th1-type response is important in primary infection. This is the first study to demonstrate protective immunity against M. haemofelis reinfection, and it provides important information for potential future hemoplasma vaccine design.

  • Establishment and characterization of a low-dose Mycoplasma haemofelis infection model.
    Veterinary microbiology, 2013
    Co-Authors: Julia Baumann, Barbara Riond, Felicitas S. Boretti, Marilisa Novacco, Regina Hofmann-lehmann
    Abstract:

    Hemotropic Mycoplasma are small, cell-wall-free bacteria that can infect various mammalian species, including humans. They cannot be cultured in vitro; therefore, animal models play an important role, e.g. for pathogenesis studies. Mycoplasma haemofelis (Mhf) is the most pathogenic of the three feline hemotropic Mycoplasma species; it is known to induce severe hemolytic anemia in infected cats. The aims of this study were to establish and characterize a low-dose Mhf transmission model. Five specified pathogen-free cats were subcutaneously exposed to 1000 copies of Mhf per cat corresponding to 0.05 μL of infectious blood with 2×10(7) copies/mL as determined by real-time PCR. All cats became PCR-positive within 34 days post-exposure and reached a maximum blood Mhf load of 10(9) copies/mL, similar to previously reported high-dose infections. In a selected sample of modified Wright-stained blood smears, small epicellular coccoid structures on the surface of the red blood cells were identified by light microscopy. Additionally, using an Mhf rDnaK ELISA, seroconversion was demonstrated in all cats within 4-5 weeks after Mhf exposure. Four out of five cats developed anemia. While three cats showed only mild clinical signs of hemoplasmosis, one cat developed severe anemia and required antibiotic treatment. Our study demonstrated that minimal contact with Mhf infectious blood was sufficient for transmission of the infection and the induction of hemoplasmosis. This low-dose Mhf infection might more accurately mirror the natural route of infection, i.e., by arthropod vectors or aggressive interaction among cats. We therefore recommend this protocol for use in future animal model studies.

Barbara Willi - One of the best experts on this subject based on the ideXlab platform.

  • Consecutive antibiotic treatment with doxycycline and marbofloxacin clears bacteremia in Mycoplasma haemofelis-infected cats.
    Veterinary microbiology, 2018
    Co-Authors: Marilisa Novacco, Sarah Sugiarto, Andrea M. Spiri, Barbara Willi, Barbara Riond, Felicitas S. Boretti, Angelina Oestmann, Julia Baumann, Hanspeter Naegeli, Regina Hofmann-lehmann
    Abstract:

    Mycoplasma haemofelis is the most pathogenic feline hemoplasma species and a causative agent of infectious hemolytic anemia in cats. Current treatment protocols are effective in reducing M. haemofelis blood loads and clinical signs but consistent bacteremia clearance is rarely achieved. The aim of this study was to develop an antibiotic treatment protocol capable of clearing M. haemofelis bacteremia. Doxycycline and marbofloxacin treatment protocols were evaluated in chronically M. haemofelis infected cats in two pre-experiments and a controlled treatment study (main experiment) using five treated and four untreated cats. The blood bacterial loads in the main experiment were monitored weekly by real-time PCR for 203 days. Cats were treated with doxycycline (5 mg/kg bid orally) for 28 days. Cats that remained M. haemofelis PCR-positive or became positive again (all 5 cats in the main experiment) were switched to marbofloxacin treatment (2 mg/kg sid orally) for 14 days; then, all cats were PCR-negative. Immunosuppression after the antibiotic treatment did not lead to reactivation of bacteremia. Fine needle aspirates of different organs and bone marrow collected before and after immunosuppression were PCR-negative. Overall, 5 cats cleared bacteremia with doxycycline alone (showing lower bacterial loads at the treatment start), while 10 cats needed to be switched to marbofloxacin. Based on our results, we recommend doxycycline treatment (10 mg/kg up to 28 days) for clearance of M. haemofelis infection and monitoring bacterial loads by real-time PCR. Only if bacteremia persists or reoccurs, antibiotic treatment should be switched to marbofloxacin (2 mg/kg sid for 14 days).

  • Passive immunization does not provide protection against experimental infection with Mycoplasma haemofelis
    Veterinary Research, 2016
    Co-Authors: Sarah Sugiarto, Andrea M. Spiri, Luisa H.monteiro De Miranda, Barbara Riond, Regina Hofmann-lehmann, Felicitas S. Boretti, Marina L Meli, Marilisa Novacco, Angelina Oestmann, Barbara Willi
    Abstract:

    Mycoplasma haemofelis (Mhf) is the most pathogenic feline hemotropic Mycoplasma. Cats infected with Mhf that clear bacteremia are protected from Mhf reinfection, but the mechanisms of protective immunity are unresolved. In the present study we investigated whether the passive transfer of antibodies from Mhf-recovered cats to naïve recipient cats provided protection against bacteremia and clinical disease following homologous challenge with Mhf; moreover, we characterized the immune response in the recipient cats. Ten specified pathogen-free (SPF) cats were transfused with pooled plasma from cats that had cleared Mhf bacteremia; five control cats received plasma from naïve SPF cats. After homologous challenge with Mhf, cats were monitored for 100 days using quantitative PCR, hematology, blood biochemistry, Coombs testing, flow cytometry, DnaK ELISA, and red blood cell (RBC) osmotic fragility (OF) measurement. Passively immunized cats were not protected against Mhf infection but, compared to control cats, showed significantly higher RBC OF and B lymphocyte (CD45R/B220(+)) counts and occasionally higher lymphocyte, monocyte and activated CD4(+) T lymphocyte (CD4(+)CD25(+)) counts; they also showed higher bilirubin, total protein and globulin levels compared to those of control cats. At times of peak bacteremia, a decrease in eosinophils and lymphocytes, as well as subsets thereof (B lymphocytes and CD5(+), CD4(+) and CD8(+) T lymphocytes), and an increase in monocytes were particularly significant in the passively immunized cats. In conclusion, passive immunization does not prevent bacteremia and clinical disease following homologous challenge with Mhf, but enhances RBC osmotic fragility and induces a pronounced immune response.

  • Lack of cross-protection against Mycoplasma haemofelis infection and signs of enhancement in “Candidatus Mycoplasma turicensis”-recovered cats
    Veterinary Research, 2015
    Co-Authors: Julia Baumann, Barbara Willi, Barbara Riond, Felicitas S. Boretti, Marina L Meli, Marilisa Novacco, Regina Hofmann-lehmann
    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.

  • lack of cross protection against Mycoplasma haemofelis infection and signs of enhancement in candidatus Mycoplasma turicensis recovered cats
    Veterinary Research, 2015
    Co-Authors: Julia Baumann, Barbara Willi, Barbara Riond, Felicitas S. Boretti, Marina L Meli, Marilisa Novacco, Regina Hofmannlehmann
    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 naive 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.

  • Protective immunity against infection with Mycoplasma haemofelis
    Clinical and Vaccine Immunology, 2015
    Co-Authors: Chelsea A.e. Hicks, Barbara Willi, Christopher R Helps, Barbara Riond, Regina Hofmann-lehmann, Christopher R. Stokes, Marina L Meli, Marilisa Novacco, Sybil Tasker
    Abstract:

    Hemoplasmas are potentially zoonotic Mycoplasmal pathogens, which are not consistently cleared by antibiotic therapy. Mycoplasma haemofelis is the most pathogenic feline hemoplasma species. The aim of this study was to determine how cats previously infected with M. haemofelis that had recovered reacted when rechallenged with M. haemofelis and to characterize the immune response following de novo M. haemofelis infection and rechallenge. Five specific-pathogen-free (SPF)-derived naive cats (group A) and five cats that had recovered from M. haemofelis infection (group B) were inoculated subcutaneously with M. haemofelis. Blood M. haemofelis loads were measured by quantitative PCR (qPCR), antibody response to heat shock protein 70 (DnaK) by enzyme-linked immunosorbent assay (ELISA), blood lymphocyte cell subtypes by flow cytometry, and cytokine mRNA levels by quantitative reverse transcriptase PCR. Group A cats all became infected with high bacterial loads and seroconverted, while group B cats were protected from reinfection, thus providing the unique opportunity to study the immunological parameters associated with this protective immune response against M. haemofelis. First, a strong humoral response to DnaK was only observed in group A, demonstrating that an antibody response to DnaK is not important for protective immunity. Second, proinflammatory cytokine interleukin-6 (IL-6) mRNA levels appeared to increase rapidly postinoculation in group B, indicating a possible role in protective immunity. Third, an increase in IL-12p35 and -p40 mRNA and decrease in the Th2/Th1 ratio observed in group A suggest that a Th1-type response is important in primary infection. This is the first study to demonstrate protective immunity against M. haemofelis reinfection, and it provides important information for potential future hemoplasma vaccine design.

Marina L Meli - One of the best experts on this subject based on the ideXlab platform.

  • Passive immunization does not provide protection against experimental infection with Mycoplasma haemofelis
    Veterinary Research, 2016
    Co-Authors: Sarah Sugiarto, Andrea M. Spiri, Luisa H.monteiro De Miranda, Barbara Riond, Regina Hofmann-lehmann, Felicitas S. Boretti, Marina L Meli, Marilisa Novacco, Angelina Oestmann, Barbara Willi
    Abstract:

    Mycoplasma haemofelis (Mhf) is the most pathogenic feline hemotropic Mycoplasma. Cats infected with Mhf that clear bacteremia are protected from Mhf reinfection, but the mechanisms of protective immunity are unresolved. In the present study we investigated whether the passive transfer of antibodies from Mhf-recovered cats to naïve recipient cats provided protection against bacteremia and clinical disease following homologous challenge with Mhf; moreover, we characterized the immune response in the recipient cats. Ten specified pathogen-free (SPF) cats were transfused with pooled plasma from cats that had cleared Mhf bacteremia; five control cats received plasma from naïve SPF cats. After homologous challenge with Mhf, cats were monitored for 100 days using quantitative PCR, hematology, blood biochemistry, Coombs testing, flow cytometry, DnaK ELISA, and red blood cell (RBC) osmotic fragility (OF) measurement. Passively immunized cats were not protected against Mhf infection but, compared to control cats, showed significantly higher RBC OF and B lymphocyte (CD45R/B220(+)) counts and occasionally higher lymphocyte, monocyte and activated CD4(+) T lymphocyte (CD4(+)CD25(+)) counts; they also showed higher bilirubin, total protein and globulin levels compared to those of control cats. At times of peak bacteremia, a decrease in eosinophils and lymphocytes, as well as subsets thereof (B lymphocytes and CD5(+), CD4(+) and CD8(+) T lymphocytes), and an increase in monocytes were particularly significant in the passively immunized cats. In conclusion, passive immunization does not prevent bacteremia and clinical disease following homologous challenge with Mhf, but enhances RBC osmotic fragility and induces a pronounced immune response.

  • Lack of cross-protection against Mycoplasma haemofelis infection and signs of enhancement in “Candidatus Mycoplasma turicensis”-recovered cats
    Veterinary Research, 2015
    Co-Authors: Julia Baumann, Barbara Willi, Barbara Riond, Felicitas S. Boretti, Marina L Meli, Marilisa Novacco, Regina Hofmann-lehmann
    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.

  • lack of cross protection against Mycoplasma haemofelis infection and signs of enhancement in candidatus Mycoplasma turicensis recovered cats
    Veterinary Research, 2015
    Co-Authors: Julia Baumann, Barbara Willi, Barbara Riond, Felicitas S. Boretti, Marina L Meli, Marilisa Novacco, Regina Hofmannlehmann
    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 naive 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.

  • Protective immunity against infection with Mycoplasma haemofelis
    Clinical and Vaccine Immunology, 2015
    Co-Authors: Chelsea A.e. Hicks, Barbara Willi, Christopher R Helps, Barbara Riond, Regina Hofmann-lehmann, Christopher R. Stokes, Marina L Meli, Marilisa Novacco, Sybil Tasker
    Abstract:

    Hemoplasmas are potentially zoonotic Mycoplasmal pathogens, which are not consistently cleared by antibiotic therapy. Mycoplasma haemofelis is the most pathogenic feline hemoplasma species. The aim of this study was to determine how cats previously infected with M. haemofelis that had recovered reacted when rechallenged with M. haemofelis and to characterize the immune response following de novo M. haemofelis infection and rechallenge. Five specific-pathogen-free (SPF)-derived naive cats (group A) and five cats that had recovered from M. haemofelis infection (group B) were inoculated subcutaneously with M. haemofelis. Blood M. haemofelis loads were measured by quantitative PCR (qPCR), antibody response to heat shock protein 70 (DnaK) by enzyme-linked immunosorbent assay (ELISA), blood lymphocyte cell subtypes by flow cytometry, and cytokine mRNA levels by quantitative reverse transcriptase PCR. Group A cats all became infected with high bacterial loads and seroconverted, while group B cats were protected from reinfection, thus providing the unique opportunity to study the immunological parameters associated with this protective immune response against M. haemofelis. First, a strong humoral response to DnaK was only observed in group A, demonstrating that an antibody response to DnaK is not important for protective immunity. Second, proinflammatory cytokine interleukin-6 (IL-6) mRNA levels appeared to increase rapidly postinoculation in group B, indicating a possible role in protective immunity. Third, an increase in IL-12p35 and -p40 mRNA and decrease in the Th2/Th1 ratio observed in group A suggest that a Th1-type response is important in primary infection. This is the first study to demonstrate protective immunity against M. haemofelis reinfection, and it provides important information for potential future hemoplasma vaccine design.

  • Molecular detection of haemotropic Mycoplasma species in Rhipicephalus sanguineus tick species collected on lions (Panthera leo) from Ngorongoro Crater, Tanzania
    South African Journal of Wildlife Research, 2008
    Co-Authors: Robert D. Fyumagwa, Barbara Willi, Regina Hofmann-lehmann, Marina L Meli, Pascale Simmler, Armin Sutter, Richard Hoare, Gottfried Dasen, Hans Lutz
    Abstract:

    Abstract Haemotropic Mycoplasma species are pathogens that can cause haemolytic anaemia in susceptible mammalian species worldwide. The cause of haemolysis is due to membrane damage through stimulation of IgM cold agglutinins production, which induces autoimmune haemolysis of infected erythrocytes. A study was conducted to establish the prevalence of Mycoplasma haemofelis, ‘Candidatus Mycoplasma haemominutum’ and ‘Candidatus M. turicensis’in ticks and the diversity of tick species that are possible vectors of the pathogens that can transmit the infection to wildlife in Ngorongoro Crater. Three real-time PCR assays were used for the analysis of DNA pools (n = 507) derived from 11 tick species. Mycoplasma haemofelis and ‘Candidatus M. haemominutum’ were detected in Rhipicephalus sanguineus. On average 19.7% and 12.9% of R. sanguineus were PCR-positive for M. haemofelis and ‘Candidatus M. haemominutum’, respectively. This tick species therefore represent an important reservoir for feline haemotropic Mycoplas...

Séverine Tasker - One of the best experts on this subject based on the ideXlab platform.

  • Acute phase response to Mycoplasma haemofelis and 'Candidatus Mycoplasma haemominutum' infection in FIV-infected and non-FIV-infected cats.
    Veterinary Journal, 2012
    Co-Authors: Rachel M Korman, Emily N. Barker, Toby G Knowles, José J. Cerón, Peter David Eckersall, Séverine Tasker
    Abstract:

    The pathogenicity of Haemoplasma spp. in cats varies with 'Candidatus Mycoplasma haemominutum' (CMhm) causing subclinical infection while Mycoplasma haemofelis (Mhf) often induces haemolytic anaemia. The aims of this study were to characterise the acute phase response (APR) of the cat to experimental infection with Mhf or CMhm, and to determine whether chronic feline immunodeficiency virus (FIV) infection influences this response. The acute phase proteins serum amyloid A (SAA), haptoglobin (Hp) and α-1-acid glycoprotein (AGP) concentrations were measured pre-infection and every 7-14 days up to day 100 post-infection (pi) in cats infected with either Mhf or CMhm. Half of each group of cats (6/12) were chronically and subclinically infected with FIV. Marbofloxacin treatment was given on days 16-44 pi to half of the Mhf-infected cats, and on days 49-77 pi to half of the CMhm-infected cats. FIV-infected animals had significantly lower AGP concentrations, and significantly greater Hp concentrations than non-FIV-infected cats when infected with CMhm and Mhf, respectively. Both CMhm and Mhf infection were associated with significant increases in SAA concentrations, while AGP concentrations were only significantly increased by Mhf infection. Mhf-infected cats had significantly greater SAA concentrations than CMhm-infected animals. Both Mhf and CMhm infections were associated with an APR, with Mhf infection inducing a greater response. Chronic FIV infection appeared to modify the APR, which varied with the infecting Haemoplasma species.

  • Molecular characterization of the uncultivatable hemotropic bacterium Mycoplasma haemofelis
    Veterinary Research, 2011
    Co-Authors: Emily N. Barker, Christopher R Helps, Iain R. Peters, Kate J. Heesom, Christopher J. Arthur, Alistair C. Darby, Alan D Radford, Ben Crossett, Margaret A Hughes, Séverine Tasker
    Abstract:

    Mycoplasma haemofelis is a pathogenic feline hemoplasma. Despite its importance, little is known about its metabolic pathways or mechanism of pathogenicity due to it being uncultivatable. The recently sequenced M. haemofelis str. Langford 1 genome was analysed and compared to those of other available hemoplasma genomes. Analysis showed that in hemoplasmas genes involved in carbohydrate metabolism are limited to enzymes of the glycolytic pathway, with glucose appearing to be the sole energy source. The majority of the pentose phosphate pathway enzymes that catalyze the de novo synthesis of ribonucleotides were absent, as were cell division protein FtsZ and chaperonins GroEL/ES. Uncharacterized protein paralogs containing putative surface expression motifs, comprised 62% of M. haemofelis and 19% of Mycoplasma suis genome coverage respectively, the majority of which were present in a small number of unstructured islands. Limited mass spectrometry and immunoblot data matched a number of characterized proteins and uncharacterized paralogs, confirming their expression and immunogenicity in vivo. These data have allowed further characterization of these important pathogens, including their limited metabolic capabilities, which may contribute to their uncultivatable status. A number of immunogenic proteins, and a potential mechanism for host immune system evasion, have been identified.

  • Complete Genome Sequence of Mycoplasma haemofelis, a Hemotropic Mycoplasma
    Journal of bacteriology, 2011
    Co-Authors: Emily N. Barker, Christopher R Helps, Iain R. Peters, Alistair C. Darby, Alan D Radford, Séverine Tasker
    Abstract:

    Here, we present the genome sequence of Mycoplasma haemofelis strain Langford 1, representing the first hemotropic Mycoplasma (hemoplasma) species to be completely sequenced and annotated. Originally isolated from a cat with hemolytic anemia, this strain induces severe hemolytic anemia when inoculated into specific-pathogen-free-derived cats. The genome sequence has provided insights into the biology of this uncultivatable hemoplasma and has identified potential molecular mechanisms underlying its pathogenicity.

  • Detection of humoral response using a recombinant heat shock protein 70, DnaK, of Mycoplasma haemofelis in experimentally and naturally hemoplasma-infected cats.
    Clinical and Vaccine Immunology, 2010
    Co-Authors: Emily N. Barker, Christopher R Helps, Regina Hofmann-lehmann, Iain R. Peters, Kate J. Heesom, Christopher J. Arthur, Séverine Tasker
    Abstract:

    Hemoplasmas is the trivial name given to a group of erythrocyte-parasitizing bacteria of the genus Mycoplasma. Of the feline hemoplasmas, Mycoplasma haemofelis is the most pathogenic, while "Candidatus Mycoplasma haemominutum" and "Candidatus Mycoplasma turicensis" are less pathogenic. Shotgun libraries of fragmented M. haemofelis genomic DNA were constructed, and random colonies were selected for DNA sequencing. In silico-translated amino acid sequences of putative open reading frames were compared to mass spectrometry data from M. haemofelis protein spots identified as being immunogenic by two-dimensional gel electrophoresis and Western blotting. Three of the spots matched the predicted sequences of a heat shock protein 70 (DnaK) homolog, elongation factor Ts, and a fragment of phosphoglycerate kinase found during library screening. A full-length copy of the M. haemofelis dnaK gene was cloned into Escherichia coli and recombinantly expressed. Recombinant M. haemofelis DnaK was purified and then used in Western blotting and an enzyme-linked immunosorbent assay (ELISA) to investigate the humoral immune response during acute infection in cats experimentally infected with M. haemofelis, "Ca. Mycoplasma haemominutum," or "Ca. Mycoplasma turicensis". The recombinant M. haemofelis DnaK ELISA also was used to screen clinical samples submitted for hemoplasma PCR testing to a commercial laboratory (n = 254). Experimentally infected cats became seropositive following infection, with a greater and earlier antibody response seen in cats inoculated with M. haemofelis than those seen in cats inoculated with "Ca. Mycoplasma haemominutum" or "Ca. Mycoplasma turicensis," by both Western blotting and ELISA. Of the clinical samples, 31.1% had antibodies detected by the ELISA but only 9.8% were positive by PCR for one or more hemoplasmas.

  • Antigen Specificity of the Humoral Immune Response to Mycoplasma haemofelis Infection
    Clinical and vaccine immunology : CVI, 2010
    Co-Authors: Iain R. Peters, Christopher R Helps, Michael J. Day, Tim Gruffydd-jones, Séverine Tasker
    Abstract:

    The aim of the present study was to characterize the antigenic specificity of the humoral immune response made by cats infected with the feline hemoplasma, Mycoplasma haemofelis. A crude M. haemofelis antigen preparation was prepared from red blood cells (RBCs) collected from a cat at the time of a high level of bacteremia. Plasma samples were collected from six cats before and after experimental infection with M. haemofelis, with regular sampling being performed from 15 to 149 or 153 days postinfection (dpi). Preinfection RBC membrane ghosts were prepared from these six cats and used to identify erythrocyte proteins that may have contaminated the M. haemofelis antigen preparation. The M. haemofelis antigen preparation comprised 11 protein bands. The immunodominant bands on Western blotting with infected cat plasma had molecular masses of 78, 68, 60, 48, and 38 kDa. Most cats (n = 5) had plasma antibody that reacted with at least one band (always including the one of 68 kDa) at 15 dpi, and all cats were seroreactive by 29 dpi. The maximum number of antibodies from an individual animal specific for an antigen was identified in plasma collected from 57 to 99 dpi. Contamination of the M. haemofelis antigen preparation with RBC membrane proteins was observed. The contaminating RBC proteins had molecular masses of from 71 to 72 kDa (consistent with band 4.2) and 261 and 238 kDa (consistent with spectrin), and these were recognized by all plasma samples. A range of M. haemofelis antigens is recognized by cats infected experimentally with the organism. These represent possible targets for immunoassays, but care must be taken to prevent false-positive results due to host protein contamination.

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  • Amplification of Mycoplasma haemofelis DNA by a PCR for point-of-care use.
    Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians Inc, 2017
    Co-Authors: Jennifer R. Hawley, Tal Yaaran, Sarah Maurice, Michael R. Lappin
    Abstract:

    We compared a qualitative in-clinic (IC)-PCR for the detection of Mycoplasma haemofelis DNA with the results of a commercial qualitative laboratory-based, conventional (c)PCR. In order to determine the specificity of both tests, Bartonella spp. samples were included. Forty-three previously tested blood samples with known PCR results for hemoplasmas and Bartonella spp. were selected. The samples were split between 2 laboratories. At the first laboratory, DNA was purified and run on 2 cPCR assays for the detection of hemoplasmas and Bartonella spp. At the second laboratory, DNA was purified using 2 purification protocols and both run in the IC-PCR assay. The cPCR results confirmed that 18 samples were positive for M. haemofelis, 5 for ' Candidatus M. haemominutum', 8 for Bartonella henselae, 2 for Bartonella clarridgeiae, and 10 were negative for both genera. No mixed infections were observed. The IC-PCR assay for the detection of M. haemofelis had a sensitivity of 94.4% and specificity of 96%, when using the same DNA purification method as the first laboratory. Using the second purification method, the sensitivity of the IC-PCR assay was 77.8% and specificity was 96%. Bartonella species were not detected by the IC-PCR M. haemofelis assay. The IC-PCR assay decreased the amount of time to final result compared to a cPCR assay.

  • Assessment of the ability of Aedes species mosquitoes to transmit feline Mycoplasma haemofelis and ' Candidatus Mycoplasma haemominutum'.
    Journal of Feline Medicine and Surgery, 2016
    Co-Authors: Krystle L. Reagan, Lorelei L. Clarke, Jennifer R. Hawley, Phillip Lin, Michael R. Lappin
    Abstract:

    ObjectivesThe objective of this study was to evaluate wild-caught mosquitoes for evidence of hemotropic Mycoplasma species DNA and to determine whether the feline hemoplasmas, Mycoplasma haemofelis (Mhf) and ‘Candidatus Mycoplasma haemominutum’ (Mhm), can be transmitted by Aedes aegypti mosquitoes in a laboratory setting.MethodsWild-caught mosquito pools (50 mosquitoes per pool, 84 pools) utilized in routine public health department disease surveillance programs were tested for hemotropic Mycoplasma species DNA using PCR with primers designed to amplify all known hemoplasmas. Additionally, mosquitoes were trapped in the vicinity of known feral cat colonies, pooled (50 mosquitoes per pool) and tested (84 pools). Purpose-bred cats housed in a research facility were infected with Mhf or Mhm and then colonized laboratory A aegypti were fed upon the bacteremic cats. After a 7 day incubation period, mosquitoes previously fed on infected cats were allowed to feed again on naive cats, which were monitored for bac...

  • Marbofloxacin for the Treatment of Experimentally Induced Mycoplasma haemofelis Infection in Cats
    Journal of veterinary internal medicine, 2008
    Co-Authors: A.m. Ishak, Jennifer R. Hawley, Kristy L. Dowers, M.t. Cavanaugh, Cynthia C. Powell, Steven V. Radecki, Michael R. Lappin
    Abstract:

    Background: Administration of tetracyclines or fluoroquinolones is associated with improvement in clinical and laboratory abnormalities in cats infected with Mycoplasma haemofelis. No treatment protocol has consistently eliminated the organism, and antimicrobial susceptibility may vary among M. haemofelis isolates. Continued search for effective therapies is warranted. Hypothesis: Marbofloxacin administered at the onset of clinical illness will be safe and effective for the treatment of M. haemofelis. Animals: Fourteen young adult, laboratory-reared cats housed together in a specific pathogen-free facility. Methods: Twelve cats were inoculated IV with 2.0 mL of blood from 2 M. haemofelis positive cats. Clinical parameters were assessed daily. CBC and hemoplasma polymerase chain reaction (PCR) assay were performed before inoculation, weekly for 1–3 weeks postinoculation (PI) and twice weekly 3–6 weeks PI. Treatment with marbofloxacin (2.75 mg/kg PO daily for 14 days) was initiated in 6 randomly selected cats when PCV was 102.5°F (39.2 °C). Cats that were PCR positive on day 7 of therapy were treated for 28 days. Cats that were PCR negative on day 42 PI were treated with 20 mg/kg methylprednisolone acetate IM on day 50 PI. Results: Significant differences between groups on some days after inoculation included higher PCV and red blood cell counts, lower mean cell volume, and higher mean cell hemoglobin content in marbofloxacin-treated cats. No differences in PCR assay results were noted between groups. Conclusions and Clinical Importance: Marbofloxacin was safe and resulted in more rapid hematologic improvement in M. haemofelis-infected cats, but did not change clinical scores and did not consistently eliminate infection.

  • Prevalence of DNA of Mycoplasma haemofelis, ‘Candidatus Mycoplasma haemominutum,’ Anaplasma phagocytophilum, and species of Bartonella, Neorickettsia, and Ehrlichia in cats used as blood donors in the United States
    Javma-journal of The American Veterinary Medical Association, 2006
    Co-Authors: Timothy B. Hackett, Wayne A. Jensen, Tracy L. Lehman, Anne E. Hohenhaus, P. Cynda Crawford, Urs Giger, Michael R. Lappin
    Abstract:

    Objective—To identify the prevalence of DNA of Mycoplasma haemofelis; ‘Candidatus Mycoplasma haemominutum’; Anaplasma phagocytophilum; and species of Bartonella, Neorickettsia, and Ehrlichia in blood of cats used as blood donors in the United States. Design—Prospective study. Animals—146 cats that were active blood donors. Procedures—Environmental history was requested for each blood-donor cat from which a blood sample (mixed with EDTA) was available. Polymerase chain reaction assays capable of amplifying the DNA of the microorganisms of interest following DNA extraction from blood were performed. Results—Overall, DNA of one or more of the infectious agents was detected in blood samples from 16 of 146 (11%) feline blood donors. Twenty-eight laboratory-reared cats housed in a teaching hospital had negative results for DNA of all organisms investigated. The DNA of at least 1 infectious agent was amplified from blood samples collected from 16 of 118 (13.6%) community-source cats; assay results were positive ...

  • prevalence of dna of Mycoplasma haemofelis candidatus Mycoplasma haemominutum anaplasma phagocytophilum and species of bartonella neorickettsia and ehrlichia in cats used as blood donors in the united states
    Javma-journal of The American Veterinary Medical Association, 2006
    Co-Authors: Timothy B. Hackett, Wayne A. Jensen, Tracy L. Lehman, Anne E. Hohenhaus, Urs Giger, Cynda P Crawford, Michael R. Lappin
    Abstract:

    Objective—To identify the prevalence of DNA of Mycoplasma haemofelis; ‘Candidatus Mycoplasma haemominutum’; Anaplasma phagocytophilum; and species of Bartonella, Neorickettsia, and Ehrlichia in blood of cats used as blood donors in the United States. Design—Prospective study. Animals—146 cats that were active blood donors. Procedures—Environmental history was requested for each blood-donor cat from which a blood sample (mixed with EDTA) was available. Polymerase chain reaction assays capable of amplifying the DNA of the microorganisms of interest following DNA extraction from blood were performed. Results—Overall, DNA of one or more of the infectious agents was detected in blood samples from 16 of 146 (11%) feline blood donors. Twenty-eight laboratory-reared cats housed in a teaching hospital had negative results for DNA of all organisms investigated. The DNA of at least 1 infectious agent was amplified from blood samples collected from 16 of 118 (13.6%) community-source cats; assay results were positive ...

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