Abstract
In the general population, Mycoplasma spp. and Ureaplasma spp. are considered as pathogens with low virulence. Asymptomatic urogenital colonization with genital mycoplasmas is common. M. pneumoniae infections most frequently present as tracheobronchitis. In immunosuppressed individuals, a broad spectrum of invasive diseases has been attributed to these pathogens. After kidney transplantation and hematopoietic stem cell transplantation, Mycoplasma spp. and Ureaplasma spp. have been detected as causative pathogens in urogenital infections. Surgical site infections following solid organ transplantation are rarely caused by Mycoplasma spp. and Ureaplasma spp.. Recently, an association between hyperammonemia syndrome and genital mycoplasmas has been described after lung, kidney, and hematopoietic stem cell transplantation. Hyperammonemia syndrome, characterized by a combination of progressive elevations in plasma ammonium levels and worsening neurological symptoms, is a rare but potentially fatal disorder. Routine cultural approaches are poorly sensitive, and nucleic acid amplification tests should be applied for diagnosis. Commonly used broad-spectrum antibiotics are frequently not active against these cell wall-lacking bacteria. Mycoplasma spp. or Ureaplasma spp. should be considered as etiologic agents if routine diagnostics do not identify relevant pathogens or if response to empiric antibiotic therapy is insufficient.