Rhodococcus equi infection after reduction mammaplasty in an immunocompetent patient

A Rare Presentation of Rhodococcus Equi Bacteremia as a Result of Right Upper Arm Cellulitis: A Case Report and Literature Review

Rhodococcus equi is an emerging opportunistic pathogen in immunocompromised patients. Owing to its resemblance to Mycobacterium, Nocardia, and Corynebacterium, R. equi is frequently misdiagnosed as a contaminant, which can result in treatment delays. A 65-year-old man with a history of end-stage renal disease (ESRD) presented to the emergency room with pain and increased swelling in his right upper extremity. Shortly after he arrived in the emergency room, his condition deteriorated. Intravenous vancomycin was administered after collecting blood cultures. The blood cultures grew Rhodococcus equi, and oral azithromycin and oral rifampin were added for a 14-day course of treatment. The patient recovered without any further complications and was subsequently discharged home.  R. equi is a partially acid-fast actinomycete that spreads through contact with grazing animals and contaminated soil. R. equi invades macrophages to survive and causes infection within a host. In this particular case, the patient worked on a farm taking care of goats. He was exposed to the bacteria after falling and sustaining multiple lacerations to the right arm. This case is unique due to the development of bacteremia with R. equi, an uncommon cause of bacteremia that led to cardiopulmonary arrest. The treatment with oral azithromycin combined with oral rifampin and intravenous vancomycin was effective for the complete resolution of the infection.

Nadir Bir Etken: Rhodococcus equi, İmmunkompetan Hastalarda Yumuşak Doku Enfeksiyonlarına İlişkin Bir Vaka Sunumu ve Literatür İncelemesi

Rhodococcus equi is a microorganism that was first described in horses and later it had been found out to cause opportunistic infections in immunosuppressed patients. It causes especially pulmonary infections in immunocompromised patients while it rarely causes diseases such as septic arthritis and soft tissue infections. It is important to question epidemiological risk factors for the diagnosis of the disease. Also the clinician-microbiologist relationship is important in the laboratory diagnosis of the microorganism because it is possible to be missed as the part of normal flora or contaminant or to be confused with microorganisms with similar phenotypic features (Nocardia species or rapidly growing mycobacteria). Rarely, it has been reported in immunocompetent patients, as in our case. MEDLINE, SCOPUS, Google Scholar, and Cochrane searches were performed using keywords Rhodococcus equi and Corynebacterium equi from 1945 to July 2021. A total of 582 articles were determined. Articles containing these keywords were then scanned for words "humans", “soft tissue infections”, and “cellulite” and a total of 42 articles were listed in the end. A total of 14 case reports of soft tissue infection/cellulitis in immunocompetent patients related R. equi were detected in the literature In our case, there was a soft tissue infection and R. equi was detected in the abscess culture. Obtaining culture and determining the factor is very important in the treatment of infections. In this report, soft tissue infections caused by R. equi in immunocompetent patients are reviewed.