Failure of antimicrobial therapy to accelerate spontaneous healing of subclinical pulmonary abscesses on a farm with endemic infections caused by Rhodococcus equi.
Abstract: Mass antimicrobial treatment of foals with small ultrasonographic pulmonary lesions is common on farms with endemic disease caused by Rhodococcus equi. The objectives of this study were to compare the relative efficacy of three antimicrobial protocols for the treatment of pulmonary abscesses on a farm with endemic infections caused by R. equi and to determine the frequency of spontaneous resolution of subclinical pulmonary lesions. Foals with ultrasonographic evidence of pulmonary abscesses ≥ 1.0 cm in diameter (n=128) were randomly allocated to one of four equal treatment groups. Animals with respiratory distress or severe pulmonary lesions were excluded from the study. Treatment groups consisted of: (1) tulathromycin intramuscularly; (2) azithromycin monotherapy orally; (3) azithromycin in combination with rifampin orally; and (4) glucose orally as a placebo. Physical examination, thoracic ultrasonography and white blood cell (WBC) counts were performed weekly by individuals unaware of treatment group assignment. Foals that worsened were removed from the study and treated with azithromycin and rifampin. Overall, 14/32 (43.8%) foals in the placebo group recovered without the need for therapy. The proportion of foals that responded to the initial therapy, the duration of therapy, the kinetics of ultrasonographic lesion resolution, the proportion of foals that had to be removed from the study and the number of days to removal from the study did not differ significantly between treatment groups. The study showed that many foals with pulmonary abscesses recover without antimicrobial therapy. Moreover, treatment of sub-clinically affected foals with antimicrobial agents did not significantly hasten recovery.
Copyright © 2011 Elsevier Ltd. All rights reserved.
Publication Date: 2011-09-15 PubMed ID: 21924651DOI: 10.1016/j.tvjl.2011.07.004Google Scholar: Lookup
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- Journal Article
- Randomized Controlled Trial
Summary
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This research investigates the treatment of pulmonary abscesses in foals caused by Rhodococcus equi and reveals that many foals recover without antimicrobial therapy, and that this therapy does not significantly hasten recovery.
Study Design and Objectives
- The research aimed to measure the effectiveness of three different treatment methods for pulmonary abscesses in foals on a farm with endemic infections caused by R. equi.
- The second objective was to determine the frequency of spontaneous resolution of subclinical pulmonary lesions.
- Foals included in the study showed ultrasonographic evidence of pulmonary abscesses, with a diameter equal to or larger than 1.0cm. They were divided evenly into four treatment groups.
Exclusions and Methodology
- Foals with respiratory distress or severe pulmonary lesions were not included in the study.
- The four groups were treated with either tulathromycin intramuscularly, azithromycin monotherapy orally, azithromycin combined with rifampin orally, or with orally administered glucose as a placebo.
- Treatment monitoring was conducted by researchers unaware of the group assignments, and involved physical examination, thoracic ultrasonography, and WBC counts conducted on a weekly basis.
Results and Study Conclusion
- Out of the placebo group, approximately 43.8% of foals recovered without the need for therapy.
- There was no significant difference in the proportion of foals that responded to initial therapy, the length of therapy, the speed of resolution of ultrasonographic lesions, the proportion of foals needing removal from the study, and the number of days until the removal, between treatment groups.
- Crucially, the research concluded that many foals with pulmonary abscesses recover without antimicrobial therapy, and that treating sub-clinically affected foals with these medications didn’t significantly speed up the recovery process.
Cite This Article
APA
Venner M, Rödiger A, Laemmer M, Giguère S.
(2011).
Failure of antimicrobial therapy to accelerate spontaneous healing of subclinical pulmonary abscesses on a farm with endemic infections caused by Rhodococcus equi.
Vet J, 192(3), 293-298.
https://doi.org/10.1016/j.tvjl.2011.07.004 Publication
Researcher Affiliations
- Veterinary Clinic, Trift 4, 38162 Destedt, Germany.
MeSH Terms
- Actinomycetales Infections / drug therapy
- Actinomycetales Infections / veterinary
- Animals
- Anti-Bacterial Agents / administration & dosage
- Anti-Bacterial Agents / therapeutic use
- Azithromycin / administration & dosage
- Azithromycin / therapeutic use
- Disaccharides / administration & dosage
- Disaccharides / therapeutic use
- Double-Blind Method
- Drug Therapy, Combination
- Endemic Diseases / veterinary
- Female
- Heterocyclic Compounds / administration & dosage
- Heterocyclic Compounds / therapeutic use
- Horse Diseases / drug therapy
- Horses
- Lung Abscess / drug therapy
- Lung Abscess / microbiology
- Lung Abscess / veterinary
- Male
- Rhodococcus equi
- Rifampin / administration & dosage
- Rifampin / therapeutic use
- Time Factors
- Treatment Failure
Citations
This article has been cited 24 times.- Cohen ND, Flores-Ahlschewde P, Gonzales GM, Kahn SK, da Silveira BP, Bray JM, King EE, Blair CC, Bordin AI. Fecal concentration of Rhodococcus equi determined by quantitative polymerase chain reaction of rectal swab samples to differentiate foals with pneumonia from healthy foals.. J Vet Intern Med 2022 May;36(3):1146-1151.
- Álvarez-Narváez S, Huber L, Giguère S, Hart KA, Berghaus RD, Sanchez S, Cohen ND. Epidemiology and Molecular Basis of Multidrug Resistance in Rhodococcus equi.. Microbiol Mol Biol Rev 2021 May 19;85(2).
- Aslam MW, Lau SF, Chin CSL, Ahmad NI, Rahman NA, Kuppusamy K, Omar S, Radzi R. Clinicopathological and radiographic features in 40 cats diagnosed with pulmonary and cutaneous Rhodococcus equi infection (2012-2018).. J Feline Med Surg 2020 Aug;22(8):774-790.
- Álvarez-Narváez S, Giguère S, Berghaus LJ, Dailey C, Vázquez-Boland JA. Horizontal Spread of Rhodococcus equi Macrolide Resistance Plasmid pRErm46 across Environmental Actinobacteria.. Appl Environ Microbiol 2020 Apr 17;86(9).
- Álvarez-Narváez S, Berghaus LJ, Morris ERA, Willingham-Lane JM, Slovis NM, Giguere S, Cohen ND. A Common Practice of Widespread Antimicrobial Use in Horse Production Promotes Multi-Drug Resistance.. Sci Rep 2020 Jan 22;10(1):911.
- Saied AA, Bryan LK, Bolin DC. Ulcerative, granulomatous glossitis and enteritis caused by Rhodococcus equi in a heifer.. J Vet Diagn Invest 2019 Sep;31(5):783-787.
- Willingham-Lane JM, Berghaus LJ, Berghaus RD, Hart KA, Giguère S. Effect of Macrolide and Rifampin Resistance on Fitness of Rhodococcus equi during Intramacrophage Replication and In Vivo.. Infect Immun 2019 Oct;87(10).
- Willingham-Lane JM, Berghaus LJ, Berghaus RD, Hart KA, Giguère S. Effect of Macrolide and Rifampin Resistance on the Fitness of Rhodococcus equi.. Appl Environ Microbiol 2019 Apr 1;85(7).
- Huber L, Giguère S, Slovis NM, Carter CN, Barr BS, Cohen ND, Elam J, Erol E, Locke SJ, Phillips ED, Smith JL. Emergence of Resistance to Macrolides and Rifampin in Clinical Isolates of Rhodococcus equi from Foals in Central Kentucky, 1995 to 2017.. Antimicrob Agents Chemother 2019 Jan;63(1).
- Trevisani MM, Hanna ES, Oliveira AF, Cardoso SA, Roque-Barreira MC, Soares SG. Vaccination of Mice with Virulence-Associated Protein G (VapG) Antigen Confers Partial Protection against Rhodococcus equi Infection through Induced Humoral Immunity.. Front Microbiol 2017;8:857.
- Rutenberg D, Venner M, Giguère S. Efficacy of Tulathromycin for the Treatment of Foals with Mild to Moderate Bronchopneumonia.. J Vet Intern Med 2017 May;31(3):901-906.
- Willingham-Lane JM, Berghaus LJ, Giguère S, Hondalus MK. Influence of Plasmid Type on the Replication of Rhodococcus equi in Host Macrophages.. mSphere 2016 Sep-Oct;1(5).
- Giguère S, Berghaus LJ, Miller CD. Clinical Assessment of a Point-of-Care Serum Amyloid A Assay in Foals with Bronchopneumonia.. J Vet Intern Med 2016 Jul;30(4):1338-43.
- Rocha JN, Cohen ND, Bordin AI, Brake CN, Giguère S, Coleman MC, Alaniz RC, Lawhon SD, Mwangi W, Pillai SD. Oral Administration of Electron-Beam Inactivated Rhodococcus equi Failed to Protect Foals against Intrabronchial Infection with Live, Virulent R. equi.. PLoS One 2016;11(2):e0148111.
- Madrigal RG, Shaw SD, Witkowski LA, Sisson BE, Blodgett GP, Chaffin MK, Cohen ND. Use of Serial Quantitative PCR of the vapA Gene of Rhodococcus equi in Feces for Early Detection of R. equi Pneumonia in Foals.. J Vet Intern Med 2016 Mar-Apr;30(2):664-70.
- Fenton CS, Buckley TC. Minimum inhibitory concentrations of erythromycin and rifampin for Rhodococcus equi during the years 2007-2014.. Ir Vet J 2015;68:23.
- Shaw SD, Cohen ND, Chaffin MK, Blodgett GP, Syndergaard M, Hurych D. Estimating the Sensitivity and Specificity of Real-Time Quantitative PCR of Fecal Samples for Diagnosis of Rhodococcus equi Pneumonia in Foals.. J Vet Intern Med 2015 Nov-Dec;29(6):1712-7.
- Whitfield-Cargile CM, Cohen ND, Suchodolski J, Chaffin MK, McQueen CM, Arnold CE, Dowd SE, Blodgett GP. Composition and Diversity of the Fecal Microbiome and Inferred Fecal Metagenome Does Not Predict Subsequent Pneumonia Caused by Rhodococcus equi in Foals.. PLoS One 2015;10(8):e0136586.
- Cohen ND, Slovis NM, Giguère S, Baker S, Chaffin MK, Bernstein LR. Gallium maltolate as an alternative to macrolides for treatment of presumed Rhodococcus equi pneumonia in foals.. J Vet Intern Med 2015 May-Jun;29(3):932-9.
- Prohl A, Lohr M, Ostermann C, Liebler-Tenorio E, Berndt A, Schroedl W, Rothe M, Schubert E, Sachse K, Reinhold P. Enrofloxacin and macrolides alone or in combination with rifampicin as antimicrobial treatment in a bovine model of acute Chlamydia psittaci infection.. PLoS One 2015;10(3):e0119736.
- Hildebrand F, Venner M, Giguère S. Efficacy of gamithromycin for the treatment of foals with mild to moderate bronchopneumonia.. J Vet Intern Med 2015 Jan;29(1):333-8.
- Gressler LT, de Vargas AC, da Costa MM, Pötter L, da Silveira BP, Sangioni LA, de Avila Botton S. Genotypic and phenotypic detection of efflux pump in Rhodococcus equi.. Braz J Microbiol 2014;45(2):661-5.
- Gudeta DD, Moodley A, Bortolaia V, Guardabassi L. vanO, a new glycopeptide resistance operon in environmental Rhodococcus equi isolates.. Antimicrob Agents Chemother 2014;58(3):1768-70.
- Burton AJ, Giguère S, Sturgill TL, Berghaus LJ, Slovis NM, Whitman JL, Levering C, Kuskie KR, Cohen ND. Macrolide- and rifampin-resistant Rhodococcus equi on a horse breeding farm, Kentucky, USA.. Emerg Infect Dis 2013 Feb;19(2):282-5.
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