ABSTRACT
Hydatid disease is a parasitic disease caused by the larval form of Echinococcus granulosus. Most common sites are liver, lungs, and brain. The disease is rarely present in the mediastinum. We report the rare instance of a 52-year-old female who presented with hydatid disease in the uncommon location of posterior mediastinum.
Subject(s)
Echinococcosis/diagnosis , Mediastinal Cyst/diagnosis , Mediastinal Cyst/parasitology , Female , Humans , Middle AgedABSTRACT
Streptococcus pneumoniae (pneumococcus) is a major cause of morbidity and mortality world-wide. The initial event in invasive pneumococcal disease is the attachment of encapsulated pneumococci to epithelial cells in the upper respiratory tract. This work provides evidence that initial bacterial adhesion and subsequent ability to cause invasive disease is enhanced by pili, long organelles able to extend beyond the polysaccharide capsule, previously unknown to exist in pneumococci. These adhesive pili-like appendages are encoded by the pneumococcal rlrA islet, present in some, but not all, clinical isolates. Introduction of the rlrA islet into an encapsulated rlrA-negative isolate allowed pilus expression, enhanced adherence to lung epithelial cells, and provided a competitive advantage upon mixed intranasal challenge of mice. Furthermore, a pilus-expressing rlrA islet-positive clinical isolate was more virulent than a nonpiliated deletion mutant, and it out-competed the mutant in murine models of colonization, pneumonia, and bacteremia. Additionally, piliated pneumococci evoked a higher TNF response during systemic infection, compared with nonpiliated derivatives, suggesting that pneumococcal pili not only contribute to adherence and virulence but also stimulate the host inflammatory response.
Subject(s)
Fimbriae, Bacterial/physiology , Genes, Bacterial/physiology , Genomic Islands , Pneumonia, Bacterial/microbiology , Streptococcus pneumoniae/genetics , Streptococcus pneumoniae/pathogenicity , Animals , Bacterial Adhesion/genetics , Bacterial Proteins/genetics , Fimbriae, Bacterial/genetics , Fimbriae, Bacterial/ultrastructure , Genes, Bacterial/genetics , Genomic Islands/genetics , Genomic Islands/physiology , Mice , Mice, Inbred C57BL , Mutation , Respiratory Mucosa/microbiology , Streptococcus pneumoniae/ultrastructure , Trans-Activators/genetics , VirulenceABSTRACT
Recognition of cutaneous herpes simplex virus (HSV) in acquired immunodeficiency syndrome (AIDS) can be difficult because of its atypical prsentations. Pneumonia in AIDS is complex with many possible etiologies. Identification of HSV preceded by atypical cutaneous manifestation and pneumonia is critical, given the poor prognosis when treatment is delayed or not prescribed. We report a 62-year-old patient with undiagnosed HIV infection who presented with disseminated cutaneous lesions resembling impetigo as his first presentation of AIDS. Subsequent confirmation that HSV was responsible led to appropriate treatment of this and the complicating HSV pneumonia. This report emphasizes the importance of the early recognition of atypical cutaneous HSV in patients with AIDS.
