Rhodococcus infection: a 10-year retrospective analysis of clinical experience and antimicrobial susceptibility profile

A Case of Pulmonary Infection Caused by Rhodococcus equi in an AIDS Patient and Literature Review

Rhodococcus equi is a rare opportunistic Gram-positive bacterium that primarily affects immunocompromised individuals, particularly those with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). The infection often presents as a multisystem, disseminated disease with rapid progression and high mortality if not promptly diagnosed and treated. We report the case of a 34-year-old male AIDS patient who developed pulmonary infection due to Rhodococcus equi. Cultures from bronchoalveolar lavage fluid, metagenomic next-generation sequencing (mNGS), and bronchoscopic brushing all indicated infection with Rhodococcus equi. Following combined anti-infective treatment, the pulmonary infection was controlled, and his condition improved. Clinicians should be alert to the possibility of Rhodococcus equi infection in AIDS patients, emphasizing early diagnosis and targeted therapy to improve patient outcomes.

Rare Bloodstream Infection of Rhodococcus rhodochrous as the Prodromal Signal for Malignancy

Rhodococcus-associated infections are extremely rare, and previous publications have indicated that such infections are primarily observed among individuals with HIV. Limited information is available regarding therapy, and no clear consensus has been reached to guide treatment. Here, we report the first case of bloodstream infection with Rhodococcus rhodochrous in a non-HIV patient with a viral intracranial infection. During follow-up, lymph node biopsy and bone marrow aspiration were performed because superficial lymphadenectasis had failed to regress as expected within 3 months. The patient was newly diagnosed with nodal T-follicular helper cell lymphoma, angioimmunoblastic-type. For cases of rare infection or co-infection, screening for pathogenic microorganisms is the priority, and several methods should be employed, such as microorganism culture, antigen and antibody detection, and metagenomic next-generation sequencing. In retrospect to integrated case management, our case indicated that early malignancy screening is significant for early diagnosis and treatment of occult cancer during patients with rare opportunistic infections.

An elderly male with septic arthritis and bacteremia

Rhodococcus hoagii is a gram positive actinomycete found in horses and cattle. Humans can be infected by ingestion or inhalation through contaminated food or soil. The organism usually infects immunosuppressed hosts with pneumonia being the common presentation. We present a case of an 89 years old, apparently immunocompetent host presenting with fever, encephalopathy and arthritis who grew Rhodococcus hoagii in blood and synovial fluid, The patient responded well to a combination of vancomycin, azithromycin and imipenem-cilastatin. Our case demonstrates that extra-pulmonary manifestations such as septic arthritis and bacteremia can be seen in immune competent hosts.