Virulence Plasmids of Rhodococcus equi Isolates From Cuban Patients With AIDS

Abstract

Rhodococcus equi is an animal pathogen and zoonotic human opportunistic pathogen associated with immunosuppressive conditions. The pathogenicity of R. equi is linked to three animal host-associated virulence plasmids encoding a family of “Virulence Associated Proteins” (VAPs). Here, the PCR-based TRAVAP molecular typing system for the R. equi virulence plasmids was applied to 26 R. equi strains isolated between 2010 and 2016 at the Institute of Tropical Medicine “Pedro Kourí,” Cuba, from individuals living with HIV/AIDS. TRAVAP detects 4 gene markers, traA common to the three virulence plasmids, and vapA, vapB, and vapN specific to each of the host-associated plasmid types (equine pVAPA, porcine pVAPB, and ruminant pVAPN). Of the 26 isolates, six were positive to the vapB (porcine-type) marker, 4 (15.4%) to the vapA (equine-type) marker, and 1 (3.8%) to the vapN (ruminant-type) marker. Most of the isolates 14 (53.8%) were negative to all TRAVAP markers, suggesting they lacked a virulence plasmid. To our knowledge, this work is the first to report the molecular characterization of R. equi isolates from Cuba. Our findings provide insight into the zoonotic origin of R. equi infections in people and the potential dispensability of the virulence plasmid in immunosuppressed patients.

Genomic Characteristics and Pan-Genome Analysis of Rhodococcus equi

“…The pathogenicity of R. equi depends on a variety of virulence factors, including capsular polysaccharide, lipid composition, extracellular enzyme and virulence plasmid ( von Bargen and Haas, 2009 ; Da et al., 2020 ; Salazar-Rodriguez et al., 2021 ). An 80 ~ 90 kb virulence plasmid with host specificity is regarded as an important virulence factor of R. equi , and the virulence-related protein (VAP) encoded by the plasmid is regarded as the key to the survival and proliferation of R. equi in macrophages ( Letek et al., 2008 ).…”

Rhodococcus equi—Occurrence in Goats and Clinical Case Report

“…Additionally, detection of R. equi in 1.1% of investigated goats’ lymph nodes is close to other studies on ruminants. Prevalence of R. equi in slaughtered cattle used to be considered very low (0.008%) [ 53 ], but more recently, R. equi was isolated from 1.3% of lesion-free lymph nodes of cattle carcasses approved for human consumption [ 16 ]. Furthermore, the low prevalence of avirulent, environmental strains of R. equi in red deer (0.7%) and roe deer (0.9%) and lack of tissue lesions indicate an accidental carriage of the pathogen [ 36 ].…”