• 1.

    McLaughlin BG, Evans CN, McLaughlin PS, et al. An Eperythrozoon-like parasite in llamas. J Am Vet Med Assoc 1990;197:11701175.

  • 2.

    Reagan WJ, Garry F, Thrall MA, et al. The clinicopathologic, light, and scanning electron microscopic features of eperythrozoonosis in four naturally infected llamas. Vet Pathol 1990;27:426431.

    • Search Google Scholar
    • Export Citation
  • 3.

    Messick JB, Walker PG, Raphael W, et al. Candidatus mycoplasma haemodidelphidis' sp. nov., ‘Candidatus mycoplasma haemolamae' sp. nov. and Mycoplasma haemocanis comb. nov., haemotrophic parasites from a naturally infected opossum (Didelphis virginiana), alpaca (Lama pacos) and dog (Canis familiaris): phylogenetic and secondary structural relatedness of their 16S rRNA genes to other mycoplasmas. Int J Syst Evol Microbiol 2002;52:693698.

    • Search Google Scholar
    • Export Citation
  • 4.

    Neimark H, Hoff B, Ganter M. Mycoplasma ovis comb. nov. (formerly Eperythrozoon ovis), an epierythrocytic agent of haemolytic anaemia in sheep and goats. Int J Syst Evol Microbiol 2004;54:365371.

    • Search Google Scholar
    • Export Citation
  • 5.

    Messick JB. Hemotrophic mycoplasma (hemoplasmas): a review and new insights into pathogenic potential. Vet Clin Pathol 2004;33:213.

  • 6.

    Almy FS, Ladd SM, Sponenberg DP, et al. Mycoplasma haemolamae infection in a 4-day-old cria: support for in utero transmision by use of a polymerase chain reaction assay. Can Vet J 2006;47:229233.

    • Search Google Scholar
    • Export Citation
  • 7.

    Barrington GM, Parish SM, Tyler JW. Chronic weight loss in an immunodeficient adult llama. J Am Vet Med Assoc 1997;211:294298.

  • 8.

    Hutchison JM, Garry FB, Belknap EB, et al. Prospective characterization of the clinicopathologic and immunologic features of an immunodeficiency syndrome affecting juvenile llamas. Vet Immunol Immunopathol 1995;49:209227.

    • Search Google Scholar
    • Export Citation
  • 9.

    Fisher DJ, Zinkl JG. Eperythrozoonosis in a one-day-old llama. Vet Clin Pathol 1996;25:9394.

  • 10.

    Messick JB, Berent LM, Cooper SK. Development and evaluation of a PCR-based assay for detection of Haemobartonella felis in cats and differentiation of H. felis from related bacteria by restriction fragment length polymorphism analysis. J Clin Microbiol 1998;36:462466.

    • Search Google Scholar
    • Export Citation
  • 11.

    Berent LM, Messick JB, Cooper SK. Detection of Haemobartonella felis in cats with experimentally induced acute and chronic infections, using a polymerase chain reaction assay. Am J Vet Res 1998;59:12151220.

    • Search Google Scholar
    • Export Citation
  • 12.

    Vandervoort JM, Bourne C, Carson RL, et al. Use of a polymerase chain reaction assay to detect infection with Eperythrozoon wenyoni in cattle. J Am Vet Med Assoc 2001;219:14321434.

    • Search Google Scholar
    • Export Citation
  • 13.

    Gwaltney SM, Hays MP, Oberst RD. Detection of Eperythrozoon suis using the polymerase chain reaction. J Vet Diagn Invest 1993;5:4046.

  • 14.

    Foley JE, Harrus S, Poland A, et al. Molecular, clinical, and pathologic comparison of two distinct strains of Haemobartonella felis in domestic cats. Am J Vet Res 1998;59:15811588.

    • Search Google Scholar
    • Export Citation
  • 15.

    Messick JB. New perspectives about Hemotrophic mycoplasma (formerly, Haemobartonella and Eperythrozoon species) infections in dogs and cats. Vet Clin North Am Small Anim Pract 2003;33:14531465.

    • Search Google Scholar
    • Export Citation
  • 16.

    Braddock JA, Tasker S, Malik R. The use of real-time PCR in the diagnosis and monitoring of Mycoplasma haemofelis copy number in a naturally infected cat. J Feline Med Surg 2004;6:161165.

    • Search Google Scholar
    • Export Citation
  • 17.

    Zachary JF, Smith AR. Experimental porcine eperythrozoonosis: T-lymphocyte suppression and misdirected immune responses. Am J Vet Res 1985;46:821830.

    • Search Google Scholar
    • Export Citation
  • 18.

    Henry SC. Clinical observations of eperythrozoonosis. J Am Vet Med Assoc 1979;174:601603.

  • 19.

    Gulland FM, Doxey DL, Scott GR. Changing morphology of Eperythrozoon ovis. Res Vet Sci 1987;43:8891.

  • 20.

    Sutton RH. The effect of Eperythrozoon ovis infection on the glucose level and some acid-base factors in the venous blood of sheep. Aust Vet J 1977;53:478481.

    • Search Google Scholar
    • Export Citation
  • 21.

    Smith JE, Cipriano JE, Hall SM. In vitro and in vivo glucose consumption in swine eperythrozoonosis. Zentralbl Veterinarmed B 1990;37:587592.

    • Search Google Scholar
    • Export Citation
  • 22.

    Westfall DS, Jensen WA, Reagan WJ, et al. Inoculation of two genotypes of Hemobartonella felis (California and Ohio variants) to induce infection in cats and the response to treatment with azithromycin. Am J Vet Res 2001;62:687691.

    • Search Google Scholar
    • Export Citation
  • 23.

    Tasker S, Caney SM, Day MJ, et al. Effect of chronic FIV infection, and efficacy of marbofloxacin treatment, on Mycoplasma haemofelis infection. Vet Microbiol 2006;117:169179.

    • Search Google Scholar
    • Export Citation
  • 24.

    Ishak AM, Dowers KL, Cavanaugh MT, et al. Marbofloxacin for the treatment of experimentally induced Mycoplasma haemofelis infection in cats. J Vet Intern Med 2008;22:288292.

    • Search Google Scholar
    • Export Citation
  • 25.

    Dowers KL, Olver C, Radecki SV, et al. Use of enrofloxacin for treatment of large-form Haemobartonella felis in experimentally infected cats. J Am Vet Med Assoc 2002;221:250253.

    • Search Google Scholar
    • Export Citation
  • 26.

    Willi B, Boretti FS, Tasker S, et al. From Haemobartonella to hemoplasma: molecular methods provide new insights. Vet Microbiol 2007;125:197209.

    • Search Google Scholar
    • Export Citation

Advertisement

Use of a polymerase chain reaction assay to study response to oxytetracycline treatment in experimental Candidatus Mycoplasma haemolamae infection in alpacas

View More View Less
  • 1 Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331.
  • | 2 Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331.
  • | 3 Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331.
  • | 4 Department of Veterinary Comparative Pathobiology, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907.

Abstract

Objective—To develop a PCR assay for Candidatus Mycoplasma haemolamae (CMhl) infection in alpacas and use it to study the efficacy of oxytetracycline treatment and development of a subclinical carrier state.

Animals—8 healthy adult alpacas.

Procedures—Alpacas initially had negative results for CMhl in blood samples via PCR assay and were experimentally infected with CMhl; 4 were treated with oxytetracycline, and 4 were not treated. All were monitored regularly via PCR assay, blood smear examination, PCV, rectal temperature, and physical examination. At 6 months after treatment, all alpacas were immunosuppressed by administration of dexamethasone and tested for CMhl.

Results—7 of 8 alpacas had positive PCR assay results 4 to 6 days after experimental infection. When organisms were detectable on a blood smear, they were seen 2 to 6 days after positive results of PCR assay. Infection was often associated with mild anemia that was usually transient. No alpacas became hypoglycemic. Oxytetracycline treatment was not associated with faster clearance of organisms or resolution of anemia, and 4 of 4 treated alpacas still had positive results of PCR assay when immunosuppressed 6 months later; 0 of 3 nontreated alpacas had positive results of PCR assay following immunosuppression. Transient fever was detected in 3 alpacas during immunosuppression.

Conclusions and Clinical Relevance—The PCR assay was more sensitive than blood smear examination for detection of infection. Clinical signs, anemia, and fever were not necessarily associated with infection. Oxytetracyline administration did not consistently clear CMhl infection. Although treated with oxytetracycline, infected alpacas remained chronic carriers.

Abstract

Objective—To develop a PCR assay for Candidatus Mycoplasma haemolamae (CMhl) infection in alpacas and use it to study the efficacy of oxytetracycline treatment and development of a subclinical carrier state.

Animals—8 healthy adult alpacas.

Procedures—Alpacas initially had negative results for CMhl in blood samples via PCR assay and were experimentally infected with CMhl; 4 were treated with oxytetracycline, and 4 were not treated. All were monitored regularly via PCR assay, blood smear examination, PCV, rectal temperature, and physical examination. At 6 months after treatment, all alpacas were immunosuppressed by administration of dexamethasone and tested for CMhl.

Results—7 of 8 alpacas had positive PCR assay results 4 to 6 days after experimental infection. When organisms were detectable on a blood smear, they were seen 2 to 6 days after positive results of PCR assay. Infection was often associated with mild anemia that was usually transient. No alpacas became hypoglycemic. Oxytetracycline treatment was not associated with faster clearance of organisms or resolution of anemia, and 4 of 4 treated alpacas still had positive results of PCR assay when immunosuppressed 6 months later; 0 of 3 nontreated alpacas had positive results of PCR assay following immunosuppression. Transient fever was detected in 3 alpacas during immunosuppression.

Conclusions and Clinical Relevance—The PCR assay was more sensitive than blood smear examination for detection of infection. Clinical signs, anemia, and fever were not necessarily associated with infection. Oxytetracyline administration did not consistently clear CMhl infection. Although treated with oxytetracycline, infected alpacas remained chronic carriers.

Contributor Notes

Supported by the Alpaca Research Foundation.

Presented in part at the 47th Annual Meeting of the American College of Veterinary Pathologists, New Orleans, December 2002.

Address correspondence to Dr. Tornquist.