Molecular characterization of clinical isolates of Rhodococcus equi with PCR assay based on virulence plasmid marker
Keywords:
Antimicrobial susceptibility, PCR, Plasmid, Rhodococcus equi, vapA geneAbstract
Rhodococcus equi is one of the most important pathogens of foals, in which it causes a disease manifesting in pyogranulomatous bronchopneumonia, abscesses, lymphadenitis or ulcerative enterocolitis. R. equi can be pathogenic to other domestic and wild animals and humans as well. Although, R. equi is prevalent in India, the work carried out in our country has not gone much beyond isolation of organism from clinical cases of foal pneumonia. Therefore, the present study was carried out for characterization of R. equi strains isolated from clinical cases based on plasmid markers (traA, vapA and vapB genes) and antibiotic sensitivity. In the present study, 298 samples (nasal swab, 136; fecal sample, 130; soil, 28; tissue, 4) were collected and processed for isolation, identification, and characterization of R. equi via biochemical test, antimicrobial susceptibility test and PCR. A total of 28 R. equi isolates could be recovered from clinical samples. All the 28 isolates were found sensitive to chloramphenicol, erythromycin, oxytetracycline, ciprofloxacine, neomycin and rifampin while resistant to ampicillin, trimethoprim, sulphadiazine, cloxacin, amikacin, cephalexin, and kanamycin in in vitro antimicrobial assay. PCR typing based on plasmid gene markers: traA, vapA, and vapB revealed that vapA plasmid was present in 26 isolates whereas it was absent in 2 isolates. Periodic monitoring of horse farm before and after foaling season is recommended for diagnosis of R. equi and initiating requisite bio-security and therapeutic measures.Downloads
References
Anzai T, Wada R, Nakanishi A, Kamada M, Takai S, Shindo Y and Tsubaki S. 1997. Comparison of tracheal aspiration with other test for diagnosis of Rhodococcus equi pneumonia in foals. Veterinary Microbiology 56 (3–4): 335–45. DOI: https://doi.org/10.1016/S0378-1135(97)00100-4
Arriaga J M, Cohen N D, Derr J N, Chaffin M K and Martens R J. 2002. Detection of Rhodococcus equi by polymerase chain reaction using species-specific nonproprietary primers. Journal of Veterinary Diagnostic and Investigation 14 (4): 347–53. DOI: https://doi.org/10.1177/104063870201400416
Benoit S, Benachour A, Taouji S, Auffray Y and Hartke A. 2001. Induction of vap genes encoded by the virulence plasmid of Rhodococcus equi during acid tolerance response. Research in Microbiology 152 (5): 439–49. DOI: https://doi.org/10.1016/S0923-2508(01)01217-7
Buckley T, McManamon E and Stanbridge S. 2007. Resistance studies of erythromycin and rifampin for Rhodococcus equi over a 10-year period. Irish Veterinary Journal 60 (12): 728– 31. DOI: https://doi.org/10.1186/2046-0481-60-12-728
Cisek A A, Rzewuska M, Witkowski L and Binek M. 2014. Antimicrobial resistance in Rhodococcus equi. Acta Biochimica Polonica 61 (4): 633–38. DOI: https://doi.org/10.18388/abp.2014_1824
Cohen N D. 2014. Rhodococcus equi foal pneumonia. Veterinary Clinics of North American Equine Practice 30 (3): 609–22. DOI: https://doi.org/10.1016/j.cveq.2014.08.010
Dias M, Bhat P, Chandrakar S and Pinto H. 2013. Rhodococcus equi: a pathogen in immunocompetent patients. Journal of Family Medicine and Primary Care 2 (3): 291–93. DOI: https://doi.org/10.4103/2249-4863.120770
Giguère S, Cohen N D, Chaffin M K, Slovis N M, Hondalus M K, Hines S A and Prescott J F. 2011. Diagnosis, treatment, control, and prevention of infections caused by Rhodococcus equi in foals. Journal of Veterinary Internal Medicine 25 (6): 1209–20. DOI: https://doi.org/10.1111/j.1939-1676.2011.00835.x
Giguère S, Lee E, Williams E, Cohen ND, Chaffin MK, Halbert N, Martens RJ, Franklin RP, Clark CC, Slovis NM. 2010. Determination of the prevalence of antimicrobial resistance to macrolide antimicrobials or rifampin in Rhodococcus equi isolates and treatment outcome in foals infected with antimicrobial-resistant isolates of R. equi. Journal of the American Veterinary Medical Association 237 (1): 74–81. DOI: https://doi.org/10.2460/javma.237.1.74
Khurana S K, Malik P, Virmani N and Singh B R.2009. Prevalence of Rhodococcus equi infection in foals. Indian Journal of Veterinary Research 18: 20–22.
Ladro´n N, Ferna´ndez M, Agu¨ero J, Zo¨rn B G, Va´zquez-Boland J A and Navas J. 2003. Rapid identification of Rhodococcus equi by a PCR assay targeting the choE gene. Journal of Clinical Microbiology 41 (7): 3241–45. DOI: https://doi.org/10.1128/JCM.41.7.3241-3245.2003
Letek M, Ocampo-Sosa A A, Sanders M, Fogarty U, Buckley T, Leadon D P, Gonza´lez P, Scortti M, Meijer W G, Parkhill J, Bentley S and Va´zquez-Boland J A. 2008. Evolution of the Rhodococcus equi vap pathogenicity island seen through comparison of host-associated vapA and vapB virulence plasmids. Journal of Bacteriology 190 (17): 5797–805. DOI: https://doi.org/10.1128/JB.00468-08
Monego F, Maboni F, Krewer C, Vargas A, Costa M and Loreto E. 2009. Molecular characterization of Rhodococcus equi from horse-breeding farms by means of multiplex PCR for the vap gene family. Current Microbiology 58 (4): 399–403. DOI: https://doi.org/10.1007/s00284-009-9370-6
Morton A C, Begg A P, Anderson G A, Takai S, Lammler C and Browning G F. 2001. Epidemiology of Rhodococcus equi strains on thoroughbred horse farms. Applied and Environmental Microbiology 67 (5): 2167–75. DOI: https://doi.org/10.1128/AEM.67.5.2167-2175.2001
Ocampo-Sosa A A, Lewis D A, Navas J, Quigley F, Callejo R, Scortti M, Leadon D P, Fogarty U and Va´zquez-Boland J A. 2007. Molecular epidemiology of Rhodococcus equi based on traA, vapA, and vapB virulence plasmid markers. Journal of Infectious Disease 196 (5): 763–69. DOI: https://doi.org/10.1086/519688
Pusterla N, Wilson W D, Mapes S and Leutenegger C M. 2007. Diagnostic evaluation of real-time PCR in the detection of Rhodococcus equi in faeces and nasopharyngeal swabs from foals with pneumonia. Veterinary Record 161 (8): 272–75. DOI: https://doi.org/10.1136/vr.161.8.272
Ribeiro M G, Takai S, Guazzelli A, Lara G H, da Silva A V, Fernandes M C, Condas L A, Siqueira A K and Salerno T. 2011. Virulence genes and plasmid profiles in Rhodococcus equi isolates from domestic pigs and wild boars (Sus scrofa) in Brazil. Research in Veterinary Science 91 (3): 478–81. DOI: https://doi.org/10.1016/j.rvsc.2010.09.022
Sambrook J and Russell RW. 2001. Molecular cloning: a laboratory manual, 3rd ed. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.
Saxena V and Narwal P S. 2009. Rhodococcus equi infection in foals. Journal of Remount Veterinary Corps 48: 27–31.
Sellon D C, Besser T E, Vivrette S L and McConnico R S. 2001. Comparison of nucleic acid amplification, serology, and microbiologic culture for diagnosis of Rhodococcus equi pneumonia in foals. Journal of Clinical Microbiology 39 (4): 1289–93. DOI: https://doi.org/10.1128/JCM.39.4.1289-1293.2001
Takai S, Iimori S and Tsubaki S. 1986. Quantitative fecal culture for early diagnosis of Corynebacterium (Rhodococcus) equi enteritis in foals. Canadian Journal of Veterinary Research 50 (4): 479–84.
Takai S, Sekizaki T, Ozawa T, Sugawara T, Watanabe Y and Tsubaki S. 1991. Association between a large plasmid and 15- to 17-Kilodalton antigen in virulent Rhodococcus equi. Infection and Immunity 59 (11): 4056–60. DOI: https://doi.org/10.1128/iai.59.11.4056-4060.1991
Weinstock D M and Brown A E. 2002. Rhodococcus equi: An emerging pathogen. Clinical Infectious Disease 34(10): 1379– 85. DOI: https://doi.org/10.1086/340259
Downloads
Submitted
Published
Issue
Section
License
Copyright (c) 2015 The Indian Journal of Animal Sciences

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
The copyright of the articles published in The Indian Journal of Animal Sciences is vested with the Indian Council of Agricultural Research, which reserves the right to enter into any agreement with any organization in India or abroad, for reprography, photocopying, storage and dissemination of information. The Council has no objection to using the material, provided the information is not being utilized for commercial purposes and wherever the information is being used, proper credit is given to ICAR.