Authors: Salazar-Rodríguez Daniel, Aleaga-Santiesteban Yamilé, Iglesias Enrique, Plascencia-Hernández Arturo, Pérez-Gómez Héctor R, Calderón Enrique J, Vázquez-Boland José A, de Armas Yaxsier
Journal: Frontiers in veterinary science
Summary
# Editorial Summary: *Rhodococcus equi* Virulence Plasmid Characterisation in Cuban HIV/AIDS Patients *Rhodococcus equi* represents a significant opportunistic pathogen in immunocompromised individuals, with its virulence traditionally attributed to three host-associated plasmids encoding virulence-associated proteins (VAPs); however, the prevalence and distribution of these plasmids in human clinical isolates remains poorly characterised. Researchers applied PCR-based TRAVAP molecular typing to 26 Cuban *R. equi* strains isolated from HIV/AIDS patients between 2010 and 2016, screening for traA (common to all virulent strains) and host-specific markers: vapA (equine-type), vapB (porcine-type), and vapN (ruminant-type). Of the isolates examined, only 15 (57.7%) carried detectable virulence plasmid markers—6 possessed porcine-type plasmids, 4 (15.4%) equine-type, and 1 (3.8%) ruminant-type—whilst 14 isolates (53.8%) lacked any identifiable VAP-encoding plasmid. This work provides the first molecular characterisation of Cuban *R. equi* isolates and suggests that in severely immunosuppressed patients, the traditionally critical virulence plasmid may be dispensable for pathogenesis, implying alternative virulence mechanisms warrant investigation. For equine professionals, these findings underscore the zoonotic potential of equine *R. equi* strains and highlight the need for rigorous biosecurity and hygiene protocols, particularly when handling material from horses with respiratory disease or immunocompromised individuals.
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Practical Takeaways
- •R. equi can cause serious infections in immunocompromised humans; equine practitioners should recognize this as a zoonotic concern, particularly when handling foals with R. equi pneumonia
- •The presence of equine-type virulence plasmids in human isolates confirms horses as potential transmission sources—appropriate biosecurity and hygiene protocols are warranted in equine facilities
- •Virulence plasmids may not be essential for causing disease in severely immunosuppressed patients, complicating diagnosis and control strategies
Key Findings
- •Of 26 R. equi isolates from HIV/AIDS patients in Cuba, 15.4% carried equine-type virulence plasmid (vapA), 23.1% carried porcine-type (vapB), and 3.8% carried ruminant-type (vapN)
- •53.8% of isolates lacked detectable virulence plasmids, suggesting plasmid dispensability in immunosuppressed hosts
- •First molecular characterization of R. equi isolates from Cuba demonstrates zoonotic origins of human infections