Prospective multicenter German study on pulmonary colonization with Scedosporium /Lomentospora species in cystic fibrosis: Epidemiology and new association factors.

BACKGROUND: An increasing rate of respiratory colonization and infection in cystic fibrosis (CF) is caused by fungi of the Scedosporium apiospermum species complex or Lomentospora prolificans (Sac-Lp). These fungi rank second among the filamentous fungi colonizing the CF airways, after Aspergillus fumigatus. However, the epidemiology, clinical relevance and risk of pulmonary colonization with Sac-Lp are rarely understood in CF. The objective of the present prospective multicenter study was to study pathogen distribution and determine association factors of pulmonary Sac-Lp colonization in patients with CF. MATERIAL AND METHODS: Clinical, microbiological and laboratory data of 161 patients aged 6-59 years with CF in Germany were analyzed for Sac-Lp distribution and association factors. The free statistical software R was utilized to investigate adjusted logistic regression models for association factors. RESULTS: Of the 161 patients included in the study, 74 (56%) were male. The median age of the study cohort was 23 years (interquartile range 13-32 years). 58 patients of the total cohort (36%) were < 18 years old. Adjusted multivariate regression analysis revealed that Sac-Lp colonization was associated with younger age (OR 0.8684, 95%CI: 0.7955-0.9480, p<0.005) and less colonization with H. influenzae (OR 0.0118, 95%CI: 0.0009-0.1585, p<0.001). In addition, Sac-Lp-colonized patients had more often allergic bronchopulmonary aspergillosis (ABPA) (OR 14.6663, 95%CI: 2.1873-98.3403, p<0.01) and have been colonized more often with the mucoid phenotype of Pseudomonas aeruginosa (OR 9.8941, 95%CI: 1.0518-93.0705, p<0.05). CONCLUSION: Newly found association of ABPA and Pseudomonas revealed new probable risk factors for Sac-Lp colonization. Allergy might play a role in inducing immunologic host reactions which lead to a less effective response to species of Sac-Lp.

Allergic bronchopulmonary aspergillosis is associated with pet ownership in cystic fibrosis.

BACKGROUND: Late diagnosis of allergic bronchopulmonary aspergillosis (ABPA) is associated with significant lung function decline and morbidity in cystic fibrosis (CF). The association of ABPA and domestic pet ownership in patients with CF has not been elucidated yet. Our objective was to determine the association of ABPA with pet ownership in patients with CF. METHODS: Clinical and microbiological data from certified local patient registry were analyzed for 109 patients with CF aged 1-64 years: 55 pet owner and 54 non-pet owners. The primary outcome of the retrospective observational study was the occurrence of ABPA in pet owners and non-pet owners with CF. The free statistical software R was utilized to investigate logistic regression models for association factors. RESULTS: Of the 109 patients included in the study, 61 (56%) were female. The mean age of the total group was 25.4 ± 13.2 years. Adjusted analysis revealed that ABPA (OR 5.0227, 95% CI: 1.182-21.340, p = 0.029) was associated with pet ownership in patients with CF. Furthermore, ABPA in pet owners with CF was associated with an increased number of exacerbations (OR 6.446, 95% CI: 1.057-39.328, p = 0.043). Other outcomes did not significantly differ. CONCLUSION: Owning a pet was associated with ABPA in patients with CF. Future prospective multicenter longitudinal studies are needed to investigate chronological causality between pet ownership, ABPA development, and pulmonary exacerbations and to determine whether these estimates are generalizable for ABPA susceptible patients beyond CF (asthma, bronchiectasis).

Molecular identification of fungal pathogens in nodular skin lesions of cats.

In a retrospective study, we investigated 52 formalin-fixed, paraffin-embedded (FFPE) samples from cats with histologically confirmed cutaneous and subcutaneous mycoses to determine if the pathogens could be identified by molecular methods. Aim of the study was to obtain a deep understanding of the spectrum of infectious agents, which, as we hypothesized, was not available by histopathology alone. Detection of feline and fungal DNA was achieved in 92.3% and 94.2% of the samples, respectively. Most of the subcutaneous infections in cats were caused by Alternaria spp. (63.5%), followed by Cryptococcus neoformans (7.7%), Histoplasma capsulatum (5.8%), Sporothrix spp. (3.8%), Aspergillus vitricola, Aureobasidium pullulans, Exophiala attenuata, Fusarium oxysporum, Lecythophora cateniformis, Microsporum canis, and Phialophora sp. (1.9% each). The results from molecular identification indicate that correct identifications of the fungal pathogens by histology alone were rarely possible. The spectrum of fungal pathogens identified after DNA extraction from FFPE samples was much broader than that expected by classical histopathology. This was especially noted in alternariosis in that the micromorphological pattern in tissue was misleading and could be confused with that of cryptococcosis. Due to different susceptibilities to antifungal agents, it is important to arrive at a definitive diagnosis, which might be possible by examination of the fungus recovered in culture and/or molecular methods, in addition to the histopathologic techniques.