Hong Zhu,1,* Yongzheng Guo,2,* Hongchao Chen,3 Lingmei Ni,1 Biao Zhu,2 Tingting Qu4 

1Infection Control Department, the First Affiliated Hospital, Zhejiang University School of Medicine, Hang Zhou, Zhe Jiang, People’s Republic of China; 2The Department of Infectious Diseases, the First Affiliated Hospital, Zhejiang University School of Medicine, Hang Zhou, Zhe Jiang, People’s Republic of China; 3Clinical Laboratory, the First Affiliated Hospital, Zhejiang University School of Medicine, Hang Zhou, Zhe Jiang, People’s Republic of China; 4State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, Zhejiang University School of Medicine, Hang Zhou, Zhe Jiang, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Tingting Qu, The First Affiliated Hospital, Zhejiang University School of Medicine, No. 79, Qingchun East Road, Shangcheng District, Hangzhou, Zhejiang, Email qutingting@zju.edu.cn Biao Zhu, The First Affiliated Hospital, Zhejiang University School of Medicine, No. 79, Qingchun East Road, Shangcheng District, Hangzhou, Zhejiang, Email zhubiao1207@zju.edu.cn

Abstract: 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.

Keywords: AIDS, Rhodococcus equi, rare opportunistic infection, mNGS