{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T01:30:30Z","timestamp":1760059830793,"version":"build-2065373602"},"reference-count":41,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2025,7,12]],"date-time":"2025-07-12T00:00:00Z","timestamp":1752278400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100010200","name":"Trakia University","doi-asserted-by":"publisher","award":["B G 7 5 U N C R 7 6 3 0 3 1 0 0 1 1 7 6 2 9"],"award-info":[{"award-number":["B G 7 5 U N C R 7 6 3 0 3 1 0 0 1 1 7 6 2 9"]}],"id":[{"id":"10.13039\/501100010200","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>This case report describes the following scenario: A 56-day-old Arabian filly presented with classical symptoms of respiratory distress and a rapidly deteriorating condition, despite intensive antimicrobial treatment, resulting in death. The post-mortem examination revealed severe bronchopneumonia with characteristic disseminated pus-containing nodules. Microbiological tests and PCR confirmed the presence of R. equi carrying the virulence-associated protein A (VapA) gene. The isolate was sensitive to macrolides and fluoroquinolones but showed resistance or intermediate susceptibility to several commonly used antimicrobials. This case highlights the diagnostic and therapeutic challenges posed by this intracellular pathogen and emphasizes the importance of early detection, targeted therapy, and biosecurity measures\u2014especially in the absence of an effective commercial vaccine.<\/jats:p>","DOI":"10.3390\/ani15142058","type":"journal-article","created":{"date-parts":[[2025,7,14]],"date-time":"2025-07-14T07:54:23Z","timestamp":1752479663000},"page":"2058","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["First Detection of Rhodococcus equi in a Foal in Bulgaria\u2014A Case Report"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0006-2247-7805","authenticated-orcid":false,"given":"Betina","family":"Boneva-Marutsova","sequence":"first","affiliation":[{"name":"Department of Veterinary Microbiology, Infectious and Parasitic Diseases Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Plamen","family":"Marutsov","sequence":"additional","affiliation":[{"name":"Department of Veterinary Microbiology, Infectious and Parasitic Diseases Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Katharina","family":"Kerner","sequence":"additional","affiliation":[{"name":"Laboklin GmbH & Co. KG, 97688 Bad Kissingen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Georgi","family":"Zhelev","sequence":"additional","affiliation":[{"name":"Department of Veterinary Microbiology, Infectious and Parasitic Diseases Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,7,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"755","DOI":"10.1099\/ijs.0.053322-0","article-title":"Rhodococcus defluvii sp. nov., isolated from wastewater of a bioreactor and formal proposal to reclassify [Corynebacterium hoagii] and Rhodococcus equi as Rhodococcus hoagii comb. nov","volume":"64","author":"Kampfer","year":"2013","journal-title":"Int. J. Syst. Evol. Microbiol."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"\u017bychska, M., Witkowski, L., Klementowska, A., Rzewuska, M., Kwiecie\u0144, E., Stefa\u0144ska, I., Czopowicz, M., Szalu\u015b-Jordanow, O., Mickiewicz, M., and Moroz, A. (2021). Rhodococcus equi-Occurrence in Goats and Clinical Case Report. Pathogens, 10.","DOI":"10.3390\/pathogens10091141"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1221","DOI":"10.1111\/j.1939-1676.2011.00804.x","article-title":"Rhodococcus equi: Clinical Manifestations, Virulence, and Immunity","volume":"25","author":"Cohen","year":"2011","journal-title":"J. Vet. Intern. Med."},{"key":"ref_4","first-page":"49","article-title":"Management of Rhodococcus equi pneumonia in foals","volume":"2013","author":"Johns","year":"2013","journal-title":"Vet. Med. Res. Rep."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1016\/j.cveq.2016.11.002","article-title":"Treatment of Infections Caused by Rhodococcus equi","volume":"33","year":"2017","journal-title":"Vet. Clin. N. Am. Equine Pract."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1177\/0300985816650244","article-title":"Rhodococcus equi Infections in Dogs","volume":"54","author":"Bryan","year":"2017","journal-title":"Vet. Pathol."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Lechinski de Paula, C., Silveira Silva, R.O., Tavanelli Hernandes, R., de Nardi Junior, G., Babboni, S.D., Trevizan Guerra, S., Paganini Listoni, F.J., Giuffrida, R., Takai, S., and Sasaki, Y. (2019). First Microbiological and Molecular Identification of Rhodococcus equi in Feces of Nondiarrheic Cats. BioMed Res. Int., 2019.","DOI":"10.1155\/2019\/4278598"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1016\/S0749-0739(02)00065-2","article-title":"Pneumonia in weanlings","volume":"19","author":"Barr","year":"2003","journal-title":"Vet. Clin. Equine Pract."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/S0749-0739(02)00064-0","article-title":"Lower respiratory problems of the neonate","volume":"19","author":"Wilkins","year":"2003","journal-title":"Vet. Clin. Equine Pract."},{"key":"ref_10","unstructured":"Quinin, P.J., Carter, M.E., Markey, B., and Carter, G.R. (2004). Clinical Veterinary Microbiology, Mosby. [2nd ed.]."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"4256","DOI":"10.1128\/AEM.02706-05","article-title":"Internally controlled real-time PCR method for quantitative species-specific detection and vapA genotyping of Rhodococcus equi","volume":"72","author":"Lewis","year":"2006","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1016\/S0378-1135(97)00085-0","article-title":"Epidemiology of Rhodococcus equi infections: A review","volume":"56","author":"Takai","year":"1997","journal-title":"Vet. Microbiol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.cveq.2022.11.002","article-title":"Rhodococcus equi\u2013What is New This Decade?","volume":"39","author":"Sanz","year":"2023","journal-title":"Vet. Clin. Equine Pract."},{"key":"ref_14","first-page":"213","article-title":"Corynebacterium equi infections in horses, 1958\u20131984: A review of 131 cases","volume":"27","author":"Zink","year":"1986","journal-title":"Can. Vet. J."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"470","DOI":"10.2746\/042516407X209217","article-title":"Rhodococcus equi infection in foals: The science of \u2018rattles\u2019","volume":"39","author":"Muscatello","year":"2007","journal-title":"Equine Vet. J."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"510","DOI":"10.2460\/javma.1998.213.04.510","article-title":"Associations between physical examination, laboratory, and radiographic findings and outcome and subsequent racing performance of foals with Rhodococcus equi infection: 115 caes (1984\u20131992)","volume":"213","author":"Ainsworth","year":"1998","journal-title":"J. Am. Vet. Med. Assoc."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"292","DOI":"10.1016\/j.vetmic.2015.01.015","article-title":"Efficacy of liposomal gentamicin against Rhodococcus equi in a mouse infection model and colocalization with R. equi in equine alveolar macrophages","volume":"176","author":"Burton","year":"2015","journal-title":"Vet. Microbiol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"855","DOI":"10.2460\/javma.235.7.855","article-title":"Extrapulmonary disorders associated with Rhodococcus equi infection in foals: 150 cases (1987\u20132007)","volume":"235","author":"Reuss","year":"2009","journal-title":"J. Am. Vet. Med. Assoc."},{"key":"ref_19","first-page":"9","article-title":"Principais doen\u00e7as dos neonatos equinos","volume":"6","author":"Rizzoni","year":"2012","journal-title":"Acta Vet. Bras."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Cywes-Bentley, C., Rocha, J.N., Bordin, A.I., Vinacur, M., Rehman, S., Zaidi, T.S., Meyer, M., Anthony, S., Lambert, M., and Vlock, D.R. (2018). Antibody to Poly-N-acetyl glucosamine provides protection against intracellular pathogens: Mechanism of action and validation in horse foals challenged with Rhodococcus equi. PLoS Pathog., 14.","DOI":"10.1371\/journal.ppat.1007160"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1111\/j.2042-3306.1991.tb04752.x","article-title":"Failure of passive immunisation by colostrum from immunised mares to protect foals against Rhodococcus equi pneumonia","volume":"23","author":"Martens","year":"1991","journal-title":"Equine Vet. J."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"797","DOI":"10.1111\/j.1939-1676.2007.tb03024.x","article-title":"Serum opsonization capacity, phagocytosis, and oxidative burst activity in neonatal foals in the intensive care unit","volume":"21","author":"Gardner","year":"2007","journal-title":"J. Vet. Intern. Med."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"462","DOI":"10.1016\/j.ejmech.2011.11.016","article-title":"Physicochemical profile of macrolides and their comparison with small molecules","volume":"47","author":"Nunhuck","year":"2012","journal-title":"Eur. J. Med. Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"193","DOI":"10.2165\/00003088-198916040-00001","article-title":"Clinical pharmacokinetic properties of the macrolide antibiotics. Effects of age and various pathophysiological states (Part I)","volume":"16","author":"Periti","year":"1989","journal-title":"Clin. Pharmacokinet."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1159\/000094668","article-title":"Principles of antibiotic penetration into abscess fluid","volume":"78","author":"Wagner","year":"2006","journal-title":"Pharmacology"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1111\/j.1365-2885.2011.01292.x","article-title":"Plasma pharmacokinetics, pulmonary distribution, and in vitro activity of gamithromycin in foals","volume":"35","author":"Berghaus","year":"2011","journal-title":"J. Vet. Pharmacol. Therap."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1016\/j.vetmic.2012.05.031","article-title":"In vitro synergy, pharmacodynamics, and postantibiotic effect of 11 antimicrobial agents against Rhodococcus equi","volume":"160","author":"Lee","year":"2012","journal-title":"Vet. Microbiol."},{"key":"ref_28","first-page":"E1","article-title":"Antimicrobial activity of tulathromycin and 14 other antimicrobials against virulent","volume":"11","author":"Carlson","year":"2010","journal-title":"Rhodococcus equi in vitro. Vet. Ther."},{"key":"ref_29","first-page":"423","article-title":"Efficacy of treatment and survival rate of foals with pneumonia: Retrospective comparison of rifampin\/azithromycin and rifampin\/tulathromycin","volume":"35","author":"Venner","year":"2019","journal-title":"Pferdeheilkunde"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"397","DOI":"10.1136\/vr.101867","article-title":"Comparison of tulathromycin, azithromycin and azithromycin-rifampin for the treatment of mild pneumonia associated with Rhodococcus equi","volume":"173","author":"Venner","year":"2013","journal-title":"Vet. Rec."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"337","DOI":"10.1016\/0378-1135(87)90121-0","article-title":"Use of erythromycin-rifampin combination in treatment of Rhodococcus equi pneumonia","volume":"14","author":"Hillidge","year":"1987","journal-title":"Vet. Microbiol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1007\/BF01964420","article-title":"Intracellular distribution and activity of antibiotics","volume":"10","author":"Tulkens","year":"1991","journal-title":"Eur. J. Clin. Microbiol. Infect. Dis."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"S13","DOI":"10.1093\/jac\/12.suppl_C.13","article-title":"Intracellular penetration and antimicrobial activity of antibiotics","volume":"12","author":"Jacobs","year":"1983","journal-title":"J. Antimicrob. Chemother."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Bongers, S., Hellebrekers, P., Leenen, L.P., Koenderman, L., and Hietbrink, F. (2019). Intracellular penetration and effects of antibiotics on Staphylococcus aureus inside human neutrophils: A comprehensive review. Antibiotics, 8.","DOI":"10.3390\/antibiotics8020054"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"100077","DOI":"10.1016\/j.microb.2024.100077","article-title":"Advances in understanding immunity to Rhodococcus equi infection and vaccine development strategies: A comprehensive review","volume":"3","author":"Jhandai","year":"2024","journal-title":"Microbe"},{"key":"ref_36","unstructured":"Wilkins, P.A., and Palmer, J.E. (2001). Rhodococcus equi infections. Recent Advances in Equine Neonatal Care, International Veterinary Information Services."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"313","DOI":"10.1016\/S0378-1135(97)00099-0","article-title":"Clinical manifestations, diagnosis, treatament and prevention of Rhodococcus equi infections in foals","volume":"56","author":"Prescott","year":"1997","journal-title":"Vet. Microbiol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"101","DOI":"10.5152\/actavet.2019.19022","article-title":"Antibacterial Efficacy of Some Antiseptics and Disinfectants against Common Bacterial Agents Isolated from Horses in Turkey","volume":"45","author":"Mete","year":"2019","journal-title":"Acta Vet. Eurasia"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1016\/j.vetmic.2018.07.017","article-title":"Fecal shedding of Rhodococcus equi in mares and foals after experimental infection of foals and effect of composting on concentrations of R. equi in contaminated bedding","volume":"223","author":"Huber","year":"2018","journal-title":"Vet. Microbiol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"734","DOI":"10.1128\/JCM.01395-08","article-title":"Detection of Virulent Rhodococcus equi in Exhaled Air Samples from Naturally Infected Foals","volume":"47","author":"Muscatello","year":"2009","journal-title":"J. Clin. Microbiol."},{"key":"ref_41","unstructured":"Plowright, W., Rossdale, P.D., and Wade, J.F. (1991). The ecology and epidemiology of Rhodococcus equi. Equine Infectious Diseases VI, R&W Publications."}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/15\/14\/2058\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:08:56Z","timestamp":1760033336000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/15\/14\/2058"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,7,12]]},"references-count":41,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2025,7]]}},"alternative-id":["ani15142058"],"URL":"https:\/\/doi.org\/10.3390\/ani15142058","relation":{},"ISSN":["2076-2615"],"issn-type":[{"type":"electronic","value":"2076-2615"}],"subject":[],"published":{"date-parts":[[2025,7,12]]}}}