L. Archer

Pseudomonas aeruginosa colonization of the allograft after lung transplantation and the risk of bronchiolitis obliterans syndrome.

Long-term survival after lung transplantation remains limited by the development of bronchiolitis obliterans syndrome (BOS). Allograft colonization with Pseudomonas aeruginosa is common particularly in recipients with BOS, but a possible etiological relationship remains unexplored. In 155 consecutive lung transplants, the development of allograft colonization with Pseudomonas was strongly associated with the development of BOS within 2 years of transplant (23.4% vs. 7.7% in those colonized and not colonized, respectively, P=0.006). Freedom from BOS was significantly shorter in those patients without any pretransplant bacterial reservoir developing de novo allograft pseudomonal colonization as compared with those remaining free of colonization (Kaplan-Meier log-rank P=0.014). The isolation of Pseudomonas preceded the diagnosis of BOS in 14 of 18 (78%) and by a median of 204 days (95% confidence interval 115–492) in patients developing both these complications. We conclude that de novo colonization of the lung allograft by Pseudomonas is strongly associated with the subsequent development of BOS.

Burkholderia cepacia complex genomovars and pulmonary transplantation outcomes in patients with cystic fibrosis

Burkholderia cepacia is a group of organisms that comprises seven genotypically distinct species (B cepacia genomovars I-VII), which are collectively known as the B cepacia complex. Preoperative infection with B cepacia is associated with a poor prognosis in lung transplant recipients with cystic fibrosis. Many centres do not, therefore, offer transplants to these individuals. Our aim was to ascertain whether or not post-transplant mortality is affected by pretransplant genomovar status. We studied archived isolates with PCR-based methods, and recorded excessive mortality in patients infected with B cepacia genomovar III, but not in those infected with other genomovars.

Prevalence and clonality of Burkholderia cepacia complex genomovars in UK patients with cystic fibrosis referred for lung transplantation

Background: It has previously been reported that patients infected with Burkholderia cenocepacia (genomovar III) before lung transplantation have a poorer outcome than those with other B cepacia complex infections. Methods: An extensive study was conducted to determine the prevalence and clonality of B cepacia complex genomovars isolated from patients referred for transplant assessment between 1989 to the present and, where appropriate, whether strain type was related to transplant outcome. Results: Isolates from 29 patients were identified as B cepacia complex organisms by molecular analysis. Thirteen patients (45%) were infected with the highly transmissible ET-12 strain of B cenocepacia recA lineage III-A, while all remaining patients were infected with genetically unique B cenocepacia, B multivorans, and B vietnamiensis strains. All previously reported deaths following transplantation were associated with ET-12 infection. Conclusions: The ET-12 strain is the predominant cause of B cenocepacia infections in patients with cystic fibrosis referred to our pulmonary transplant centre and is associated with poor transplant outcomes using standard treatment regimens.