Remote respiratory sampling and unusual Pseudomonas growths in adults with cystic fibrosis: Is there a link?

ABSTRACT

P71 Table 1 2019 cohort n=20 2021 cohort n=46 p value* Remote samples 0 (0) 31 (67.4) - Age – years, mean (SD) 36.90 (9.65) 36.98 (13.25) NS Sex – Female n (%) 14 (70) 28 (60.9) NS F508del/F508del mutation n (%) 6 (30) 19 (41) NS Maintenance inhaled antibiotic therapy n (%) 13 (65) 27 (58.7) NS CFTR modulator therapy n (%) 7 (35) 40 (87) <0.001 Unusual Pseudomonas species (n) Pseudomonas putida (4)Pseudomonas fluorescens (4)Pseudomonas rhodesiae (2)Pseudomonas synxantha (2)Other (8) Pseudomonas putida (12)Pseudomonas fluorescens (11)PseudomonasMonteilii (4)Pseudomonas libanensis (3)Pseudomonas proteolytica (3)Other (13) <0.001(See text) Clinical intervention n (%)Patient symptomatic and new therapy prescribedPatient well and no action takenPatient well and new therapy prescribedNew long-term prophylaxis initiatedIncomplete data 5 (25)3 (15)7 (35)0 (0)5 (25) 10 (21.7%)15 (32.6)8 (17.4)4 (8.7)13 (28.2) NSNSNSNSNS Regrowth of unusual Pseudomonas species on subsequent samples n (%) 1 (5) 2 (4.3) NS *Tests performed = Mann Whitney Test for processing time,t test for mean age, Chi square for ratios (Yates’ correction where data size less than 5). NS=not significantConclusionDespite nearly 50% reduction in respiratory sampling (likely a result of Covid19 and the introduction of the CFTR modulator ‘Kaftrio’), our study demonstrated more than a 2-fold increase in growths of unusual Pseudomonas species in 2021. We found an association with longer processing times, which were more common with remote sampling. Mechanisms underlying this, such as contamination, require further investigation. Importantly, our data suggest that growths may be transient and treatment not always indicated. Our results suggest caution should be exercised when interpreting samples with long processing times, but further prospective studies are required.