Decontamination and Lung Transplantation of a Patient With Cystic Fibrosis With Resistant Infections

In Vitro Screening of a 1280 FDA-Approved Drugs Library against Multidrug-Resistant and Extensively Drug-Resistant Bacteria

Alternative strategies against multidrug-resistant (MDR) bacterial infections are suggested to clinicians, such as drug repurposing, which uses rapidly available and marketed drugs. We gathered a collection of MDR bacteria from our hospital and performed a phenotypic high-throughput screening with a 1280 FDA-approved drug library. We used two Gram positive (Enterococcus faecium P5014 and Staphylococcus aureus P1943) and six Gram negative (Acinetobacter baumannii P1887, Klebsiella pneumoniae P9495, Pseudomonas aeruginosa P6540, Burkholderia multivorans P6539, Pandoraea nosoerga P8103, and Escherichia coli DSM105182 as the reference and control strain). The selected MDR strain panel carried resistance genes or displayed phenotypic resistance to last-line therapies such as carbapenems, vancomycin, or colistin. A total of 107 compounds from nine therapeutic classes inhibited >90% of the growth of the selected Gram negative and Gram positive bacteria at a drug concentration set at 10 µmol/L, and 7.5% were anticancer drugs. The common hit was the antiseptic chlorhexidine. The activity of niclosamide, carmofur, and auranofin was found against the selected methicillin-resistant S. aureus. Zidovudine was effective against colistin-resistant E. coli and carbapenem-resistant K. pneumoniae. Trifluridine, an antiviral, was effective against E. faecium. Deferoxamine mesylate inhibited the growth of XDR P. nosoerga. Drug repurposing by an in vitro screening of a drug library is a promising approach to identify effective drugs for specific bacteria.

The Impact of Resistant Bacterial Pathogens including Pseudomonas aeruginosa and Burkholderia on Lung Transplant Outcomes

Pseudomonas and Burkholderia are gram-negative organisms that achieve colonization within the lungs of patients with cystic fibrosis, and are associated with accelerated pulmonary function decline. Multidrug resistance is a hallmark of these organisms, which makes eradication efforts difficult. Furthermore, the literature has outlined increased morbidity and mortality for lung transplant (LTx) recipients infected with these bacterial genera. Indeed, many treatment centers have considered Burkholderia cepacia infection an absolute contraindication to LTx. Ongoing research has delineated different species within the B. cepacia complex (BCC), with significantly varied morbidity and survival profiles. This review considers the current evidence for LTx outcomes between the different subspecies encompassed within these genera as well as prophylactic and management options. The availability of meta-genomic tools will make differentiation between species within these groups easier in the future, and will allow more evidence-based decisions to be made regarding suitability of candidates colonized with these resistant bacteria for LTx. This review suggests that based on the current evidence, not all species of BCC should be considered contraindications to LTx, going forward.

Fatal Pandoraea nosoerga infection after combined liver-lung transplantation for cystic fibrosis: a recontamination by the pre-transplantation strain

A 26-year-old girl with a longstanding colonization by Pandoraea nosoerga underwent liver-lung transplantation for cystic fibrosis (CF) in 2018. Her brother also suffering from CF was also colonized by P. nosoerga. Despite appropriate perioperative antibiotic therapy, she had post-transplant bacteremic pneumonia caused by extensively drug-resistant P. nosoerga. Drug repurposing was used to optimize treatment options. The cause of post-transplant contamination was studied by comparative whole-genome sequencing including pre- and post-transplant strains and her brother's strains. Post-transplant contamination appeared to be due to her own pre-transplant strain, emphasizing the urgent need to study and implement effective decontamination protocols before transplantation.

Effects of Multidrug-resistant Bacteria in Donor Lower Respiratory Tract on Early Posttransplant Pneumonia in Lung Transplant Recipients Without Pretransplant Infection

BACKGROUND

Multidrug-resistant (MDR) bacteria in the lower respiratory tracts of allografts may be risk factors for early posttransplant pneumonia (PTP) that causes detrimental outcomes in lung transplant recipients (LTRs). We evaluated the effects of immediate changes in MDR bacteria in allografts on early PTP and mortality rates in LTRs.

METHODS

We reviewed 90 adult bilateral LTRs without pretransplant infections who underwent lung transplantation between October 2012 and May 2018. Quantitative cultures were performed with the bronchoalveolar lavage fluids of the allografts preanastomosis and within 3 days posttransplant. The International Society for Heart and Lung Transplantation consensus defines early PTP as pneumonia acquired within 30 days posttransplant and not associated with acute rejection.

RESULTS

MDR Acinetobacter baumannii (11/34, 32.4%) and Staphylococcus aureus (9/34, 26.5%) were identified in 24.4% (22/90) of the preanastomosis allografts. Four LTRs had the same MDR bacteria in allografts preanastomosis and posttransplant. Allograft MDR bacteria disappeared in 50% of the LTRs within 3 days posttransplant. Early PTP and all-cause in-hospital mortality rates were not different between LTRs with and without preanastomosis MDR bacteria (P = 0.75 and 0.93, respectively). MDR bacteria ≥10 CFU/mL in the lungs within 3 days posttransplant was associated with early PTP (odds ratio, 5.8; 95% confidence interval, 1.3-27.0; P = 0.03).

CONCLUSIONS

High levels of preexisting MDR bacteria in allografts did not increase early PTP and mortality rates in LTRs. Despite the small and highly selective study population, lung allografts with MDR bacteria may be safely transplanted with appropriate posttransplant antibiotic therapy.

Worldwide clinical practices in perioperative antibiotic therapy for lung transplantation

Background

Infection is the most common cause of mortality within the first year after lung transplantation (LTx). The management of perioperative antibiotic therapy is a major issue, but little is known about worldwide practices.

Methods

We sent by email a survey dealing with 5 daily clinical vignettes concerning perioperative antibiotic therapy to 180 LTx centers around the world. The invitation and a weekly reminder were sent to lung transplant specialists for a single consensus answer per center during a 3-month period.

Results

We received a total of 99 responses from 24 countries, mostly from Western Europe (n = 46) and the USA (n = 34). Systematic screening for bronchial recipient colonization before LTx was mostly performed with sputum samples (72%), regardless of the underlying lung disease. In recipients without colonization, antibiotics with activity against gram-negative bacteria resistant strains (piperacillin / tazobactam, cefepime, ceftazidime, carbapenems) were reported in 72% of the centers, and antibiotics with activity against methicillin-resistant Staphylococcus aureus (mainly vancomycin) were reported in 38% of the centers. For these recipients, the duration of antibiotics reported was 7 days (33%) or less (26%) or stopped when cultures of donor and recipients were reported negatives (12%). In recipients with previous colonization, antibiotics were adapted to the susceptibility of the most resistant strain and given for at least 14 days (67%).

Conclusion

Practices vary widely around the world, but resistant bacterial strains are mostly targeted even if no colonization occurs. The antibiotic duration reported was longer for colonized recipients.

Noteworthy Literature Published in 2018 for Thoracic Organ Transplantation

Publications of note from 2018 are reviewed for the cardiothoracic transplant anesthesiologist. Strategies to expand the availability of donor organs were highlighted, including improved donor management, accumulating experience with increased-risk donors, ex vivo perfusion techniques, and donation after cardiac death. A number of reports examined posttransplant outcomes, including outcomes other than mortality, with new data-driven risk models. Use of extracorporeal support in cardiothoracic transplantation was a prominent theme. Major changes in adult heart allocation criteria were implemented, aiming to improve objectivity and transparency in the listing process. Frailty and prehabilitation emerged as targets of comprehensive perioperative risk mitigation programs.