Chronic infection sustained by a Pseudomonas aeruginosa High-Risk clone producing the VIM-1 metallo-β-lactamase in a cystic fibrosis patient after lung transplantation

Abstract

Background: The significance of chronic lung infection by multidrug-resistant (MDR) pathogens in Cystic Fibrosis (CF) transplanted patients remains controversial, and the available information is overall limited. Here we describe the case of a chronic infection, sustained by a metallo-β-lactamase (MBL)-producing P. aeruginosa strain, in a CF patient following lung transplantation.

Methods: Twelve P. aeruginosa isolates collected from a CF patient over a 15-years follow-up period after lung transplantation were analysed for their antibiotic susceptibility profile, MBL production and clonal relatedness. Available clinical and microbiological records were reviewed.

Results: The transplanted CF patient was chronically infected by an MBL-producing P. aeruginosa strain which harboured a bla_VIM-1 determinant inserted into a novel class 1 integron. The strain exhibited an MDR phenotype and belonged to the globally widespread ST235 epidemic clonal lineage, which however is not a typical CF-associated epidemic clone. Despite the chronic infection, the long-term outcome of this patient during the post-transplant period was characterized by the absence of acute exacerbations and by a mostly stable pulmonary function.

Conclusions: This report provides one of the few descriptions of MBL-producing P. aeruginosa infections in CF patients, and the first description of such an infection after lung transplantation in these patients. Infection with the MBL-producing strain apparently did not significantly affect the patient pulmonary function.

Keywords: Carbapenemase; Chronic infection; Lung transplantation; Multidrug resistance; Pseudomonas aeruginosa; ST235.