ABSTRACT
Burkholderia cepacia complex consists of highly antibiotic resistant gram negative bacilli that are plant symbionts and also potential agents of human infection. This bacterial family's claim to fame in clinical medicine is as the scourge of cystic fibrosis patients, in whom it is a notorious respiratory pathogen. Outside of cystic fibrosis, it rarely comes to mind as an etiology of community acquired pneumonia with or without lung cavitation in immunocompetent hosts. We describe a case of an otherwise healthy, community-dwelling man who presented with subacute cavitary lung disease, the causative organism of which turned out to be Burkholderia cepacia complex. Our report is accompanied by a review of the literature, which identified an additional eleven cases in the same category. We analyze all of the available cases for the emergence of any identifiable patterns or peculiarities.
Subject(s)
Burkholderia cepacia complex/isolation & purification , Community-Acquired Infections/microbiology , Onions/microbiology , Plant Diseases/microbiology , Pneumonia/microbiology , Adolescent , Adult , Aftercare , Aged , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/therapeutic use , Bronchoalveolar Lavage/methods , Burkholderia Infections/complications , Burkholderia Infections/immunology , Burkholderia Infections/microbiology , Burkholderia cepacia complex/genetics , Burkholderia cepacia complex/pathogenicity , Community-Acquired Infections/diagnosis , Diagnosis, Differential , Endoscopic Ultrasound-Guided Fine Needle Aspiration/methods , Female , Humans , Immunocompetence/immunology , Male , Middle Aged , Pneumonia/diagnosis , Pneumonia/drug therapy , Pneumonia/pathology , Tomography, X-Ray Computed/methods , Treatment Outcome , Trimethoprim, Sulfamethoxazole Drug Combination/administration & dosage , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic useABSTRACT
Several B. cenocepacia mouse models are available to study the pulmonary infection by this Burkholderia cepacia complex (BCC) species. However, a characterized B. cenocepacia mouse model to evaluate the efficacy of potential new antibacterial therapies is not yet described. Therefore, we optimized and validated the course of infection (i.e. bacterial proliferation in lung, liver and spleen) and the efficacy of a reference antibiotic, tobramycin (TOB), in a mouse lung infection model. Furthermore, the local immune response and histological changes in lung tissue were studied during infection and treatment. A reproducible lung infection was observed when immunosuppressed BALB/c mice were infected with B. cenocepacia LMG 16656. Approximately 50 to 60% of mice infected with this BCC species demonstrated a dissemination to liver and spleen. TOB treatment resulted in a two log reduction in lung burden, prevented dissemination of B. cenocepacia to liver and spleen and significantly reduced levels of proinflammatory cytokines. As this mouse model is characterized by a reproducible course of infection and efficacy of TOB, it can be used as a tool for the in vivo evaluation of new antibacterial therapies.