Chronic cavitary pneumonia by Rhodococcus equi in a highly prevalent tuberculosis country: a diagnosis challenge

Abstract

Rhodococcus equi is a facultative aerobic, intracellular, non-motile, non-spore-forming, Gram-positive, weakly acid-fast coccobacillus belonging to the group of nocardioform actinomycetes. R. equi infections are rare opportunistic illnesses in patients with Acquired Immunodeficiency Syndrome (AIDS), associated with a high mortality rate. The most common clinical presentation of R. equi infections is a chronic cavitary pneumonia. Due to its acid-fastness, R. equi can be mistaken for others acid-fast organisms, as Mycobacterium tuberculosis. In turn, R. equi is also a gram-positive pleomorphic bacteria and can be mistaken for diphtheroids or Micrococcus organisms, being accidentally disregarded as oral contaminants in sputum cultures. Therefore, in Brazil, a highly prevalent tuberculosis (TB) country, pulmonary infections caused by R. equi may mimic pulmonary TB and represent a diagnostic challenge. Here, we report on a case of chronic cavitary pneumonia by R. equi in a Human Immunodeficiency Virus (HIV)-infected patient, focusing on diagnostic aspects.

Rhodococcus equi, primer reporte de un caso de enfermedad diseminada en el Perú

“…Todas estas manifestaciones pueden confundirse con otras infecciones oportunistas causadas por micobacterias, hongos o neoplasias como linfomas, o bien presentarse en el contexto de un síndrome de reconstitución inmune 13 . Por esto, es necesario tener una alta sospecha clínica y descartar adecuadamente otras patologías, sobre todo en un país como Perú donde la tuberculosis tiene una alta prevalencia y ambos cuadros pueden ser indistinguibles 2,14,15 . En nuestro caso clínico, el compromiso principal fue digestivo y cutáneo, con diseminación hematógena e invasión medular, llamando la atención la ausencia de compromiso pulmonar, lo cual es una forma infrecuente de presentación y que se observa principalmente en personas inmunocompetentes 3 .…”

Identification of vaccine candidates against rhodococcus equi by combining pangenome analysis with a reverse vaccinology approach

“…The insidious progression of R. equi pneumonia results in marked pathology by the time clinical signs manifest. Consequently, treatment is generally prolonged, expensive and not always successful [ 3 , 8 , 9 ]. The standard treatment for R. equi pneumonia in foals is dual antimicrobial therapy with a combination of macrolide (erythromycin, azithromycin, or clarithromycin) and rifampin [ 10 ].…”