Nosocomial Pneumonia caused by Corynebacterium amycolatum: A report of two cases and review of the literature

Nosocomial pneumonia remains a major public health concern, frequently associated with multidrug-resistant bacteria such as Acinetobacter baumannii, Pseudomonas aeruginosa, or Staphylococcus aureus. In contrast, Corynebacterium amycolatum, a Gram-positive bacillus usually regarded as a skin commensal, is rarely implicated in pulmonary infections. However, in recent years, this species has emerged as an opportunistic pathogen involved in a wide range of human infections, particularly among hospitalized and immunocompromised patients.

We report here two cases of nosocomial pneumonia in intensive care unit (ICU) patients, both under mechanical ventilation, in whom the microbiological diagnosis was confirmed by bronchoalveolar lavage (BAL). Significant growth of multidrug-resistant Corynebacterium amycolatum was obtained, and its pathogenic role was confirmed through clinical and microbiological correlation. These observations highlight the growing importance of this organism—long considered nonpathogenic—and emphasize the need for increased awareness regarding its identification and appropriate therapeutic management.