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Cystic fibrosis [keywords]
- Rapid identification of Stenotrophomonas maltophilia by peptide nucleic acid fluorescence in situ hybridization. [Journal Article]
- New Microbes New Infect 2014 May; 2(3):79-81.
The objective of this study was to develop a novel peptide nucleic acid (PNA) probe for Stenotrophomonas maltophilia identification by fluorescence in situ hybridization (FISH). The probe was evaluated using 33 human and veterinary clinical S. maltophilia isolates and 45 reference strains representing common bacterial species in the respiratory tract. The probe displayed 100% sensitivity and 100% specificity on pure cultures and allowed detection in sputum from cystic fibrosis patients. The detection limit was 10(4) CFU/mL in spiked tracheal aspirate and bronchoalveolar lavage from healthy horses. Altogether the study shows that this species-specific PNA FISH probe facilitates rapid detection of S. maltophilia in biological specimens.
- Validation of a novel real-time PCR for detecting Rasamsonia argillacea species complex in respiratory secretions from cystic fibrosis patients. [Journal Article]
- New Microbes New Infect 2014 May; 2(3):72-8.
Members of the recently introduced fungal genus Rasamsonia (formerly included in the Geosmithia genus) have been described as emerging pathogens in immunosuppressed hosts or patients with cystic fibrosis (CF). Rasamsonia species have often been misidentified as Penicillium or Paecilomyces because of similar morphological characteristics. We validated a commercially available real-time PCR assay (Primerdesign™, UK) for accurate detection of species from the Rasamsonia argillacea complex. First, we tested this assay with a collection of 74 reference strains and clinical isolates and then compared the PCR with cultures of 234 respiratory samples from 152 patients with CF from two University Hospitals in Germany and France. The assay reliably detected the three main species within the Rasamsonia argillacea species complex (R. argillacea, R. piperina, R. aegroticola), which are typically encountered in CF patients. The limit of DNA detection was between 0.01 and 1 pg/μL. Analysis of the DNA extracts from respiratory specimens of CF patients revealed that four out of the 153 patients studied (2.6%) were colonized with R. argillacea species complex. Two species from the R. argillacea complex grew in the parallel cultures from the same patients. In one patient the PCR was positive 5 months before culture. The real-time PCR assay is a sensitive and specific method for detecting the three most important species of the R. argillacea species complex encountered in the CF context. Detection of these emerging pathogens in respiratory secretions from CF patients by this novel assay may increase our understanding of the occurrence and epidemiology of the R. argillacea species complex.
- Pandoraea pulmonicola chronic colonization in a cystic fibrosis patient, France. [Journal Article]
- New Microbes New Infect 2013 Nov; 1(2):27-9.
Pandoraea are considered emerging multidrug resistant pathogens in the context of cystic fibrosis. We report herein for the first time the case of a 30-year-old woman with cystic fibrosis, living in France, who was chronically infected with Pandoraea pulmonicola and who died of Pseudomonas aeruginosa sepsis 3 weeks after bilateral lung transplantation.
- Purification and characterization of a mycelial catalase from Scedosporium boydii, a useful tool for specific antibody detection in patients with cystic fibrosis. [JOURNAL ARTICLE]
- Clin Vaccine Immunol 2014 Oct 29.
Scedosporium boydii is an opportunistic filamentous fungus which may be responsible for a wide variety of infections in immunocompetent as well as immunocompromised individuals. This fungus belongs to the Scedosporium apiospermum species complex which usually ranks second among the filamentous fungi colonizing the airways of patients with cystic fibrosis (CF) and that may lead to allergic broncho-pulmonary mycoses, sensitization or respiratory infections. Upon microbial infection, host phagocytic cells release reactive oxygen species (ROS), such as hydrogen peroxide, as part of the antimicrobial response. Catalases are known to protect pathogens against ROS by detoxification of the hydrogen peroxide. Here, we investigated the catalase equipment of S. boydii, one of the major pathogenic species in the S. apiospermum species complex. Three catalases were identified and the mycelial catalase A1 was purified to homogeneity by a three-step chromatographic process. This enzyme is a monofunctional tetrameric protein, of 460 kDa, consisting of four 82-kDa glycosylated subunits. The potential interest of this enzyme in serodiagnosis of S. apiospermum infections was then investigated by ELISA, using 64 sera from CF patients. Whatever the species involved in the S. apiospermum complex, sera from infected patients were clearly differentiated from sera from patients with an Aspergillus fumigatus infection, or from CF patients without clinical and biological signs of a fungal infection and without any fungus recovered from sputum samples. These results suggest that catalase A1 is a good candidate for the development of an immunoassay for serodiagnosis of infetions caused by the S. apiospermum complex in patients with CF.
- The clinical spectrum of pulmonary aspergillosis. [REVIEW]
- Thorax 2014 Oct 29.
The clinical presentation of Aspergillus lung disease is determined by the interaction between fungus and host. Invasive aspergillosis develops in severely immunocompromised patients, including those with neutropenia, and increasingly in the non-neutropenic host, including lung transplant recipients, the critically ill patients and patients on steroids. A high index of suspicion is required in patients without the classical risk factors as early presentation is usually silent and non-specific, pyrexia uncommon and timely treatment is crucial for survival. Invasive aspergillosis has also been diagnosed in normal hosts after massive exposure to fungal spores. Chronic pulmonary aspergillosis affects patients without obvious immune compromise, but with an underlying lung condition such as COPD or sarcoidosis, prior or concurrent TB or non-tuberculous mycobacterial disease. Aspergillus bronchitis may be responsible for persistent respiratory symptoms in patients with Aspergillus detected repeatedly in sputum without evidence of parenchymal Aspergillus disease, especially in patients with bronchiectasis and cystic fibrosis. Allergic bronchopulmonary aspergillosis affects patients with asthma and cystic fibrosis, and is important to recognise as permanent lung or airways damage may accrue if untreated. Changes in the classification of Aspergillus allergic lung disease have been proposed recently. Cases of extrinsic allergic alveolitis and chronic pulmonary aspergillosis have been observed after Aspergillus exposure. Asymptomatic colonisation of the respiratory tract needs close monitoring as it can lead to clinical disease especially with ongoing immunosuppression. The various syndromes should be viewed as a semicontinuous spectrum of disease and one form may evolve into another depending on the degree of ongoing immunosuppression.
- Exhaled Breath Condensate Pepsin: Potential Noninvasive Test for Gastroesophageal Reflux in COPD and Bronchiectasis. [JOURNAL ARTICLE]
- Respir Care 2014 Oct 28.
Acid gastroesophageal reflux is a common problem in non-cystic fibrosis bronchiectasis and COPD. Invasive methods are used to diagnose gastroesophageal reflux, but the ability to detect pulmonary microaspiration of gastric contents using this method is unclear. A noninvasive option to detect pulmonary microaspiration is to measure pepsin in exhaled breath condensate (EBC), but this has not been related to esophageal pH monitoring in these lung conditions. This study aimed to measure pepsin concentrations and pH in EBC and to determine the relationship to gastroesophageal reflux in bronchiectasis or COPD.Subjects with bronchiectasis (n = 10) or COPD (n = 10) and control subjects (n = 10) completed 24-h esophageal pH monitoring for detection of acid gastroesophageal reflux, measuring the percentage of reflux time in the proximal esophagus and the DeMeester score (DMS). Concurrently, 3 samples of EBC were collected from each subject, and pH was measured and pepsin concentrations were analyzed by enzyme-linked immunosorbent assay.EBC pepsin was detected in subjects with bronchiectasis (44%) or COPD (56%) and in control subjects (10%). A diagnosis of gastroesophageal reflux was not associated with a higher concentration of EBC pepsin in bronchiectasis (P = .21) or COPD (P = .11). EBC pepsin concentration did not correlate with DMS (rs = 0.36) or proximal reflux index (rs = 0.25) in subjects with bronchiectasis or with DMS (rs = 0.28) or proximal reflux index (rs = 0.21) in patients with COPD. EBC and sputum pepsin concentrations were moderately correlated in bronchiectasis (rs = 0.56) and in COPD (rs = 0.43).Pepsin is detectable in EBC samples in bronchiectasis and COPD. Although no association was found between pepsin concentrations and a diagnosis of gastroesophageal reflux, a moderate relationship between sputum and EBC pepsin concentrations suggests that EBC pepsin may be a useful noninvasive marker of pulmonary microaspiration.
- Comparison of virulence properties of Pseudomonas aeruginosa exposed to water and grown in rich broth. [JOURNAL ARTICLE]
- Can J Microbiol 2014 Sep 22.:1-5.
Pseudomonas aeruginosa is an opportunistic pathogen that can infect susceptible patients suffering from cystic fibrosis, immunosuppression, and severe burns. Nosocomial- and community-acquired infection is likely due to contact with water sources contaminated with P. aeruginosa. Most of what is known about the virulence properties of P. aeruginosa was derived from studies using fairly rich broths, which do not represent conditions found in water, such as low nutrient concentrations. Here, we compare biofilm production, invasion of epithelial cells, cytotoxicity, and pyocyanin production of P. aeruginosa in water with P. aeruginosa grown in rich broth. Since tap water is variable, we used a defined water medium, Fraquil, to ensure reproducibility of the results. We found that P. aeruginosa does not readily form biofilm in Fraquil. Pseudomonas aeruginosa is equally able to attach to and invade epithelial cells but is more cytotoxic after incubation in water for 30 days than when it is grown in rich broth. Moreover, P. aeruginosa produces less pyocyanin when exposed to water. Our results show that P. aeruginosa seems to have different properties when exposed to water than when grown in rich broth.
- Contrast-enhanced ultrasound (CEUS) in nephrology: Has the time come for its widespread use? [JOURNAL ARTICLE]
- Clin Exp Nephrol 2014 Oct 29.
Grey-scale ultrasound has an important diagnostic role in nephrology. The absence of ionizing radiations and nephrotoxicity, rapidity of execution, excellent repeatability, the possibility to perform the test at the patient's bed and the low cost represent important advantages of this technique. Paired with real-time sonography and colour-power-Doppler contrast-enhanced ultrasound (CEUS) reduces the diagnostic gap with computed tomography (CT) and magnetic resonance (MR) and represents a major step in the evolution of clinical ultrasound. Although there are several situations in which contrast-enhanced CT and MR are indicated (i.e. evaluation of cystic or ischemic lesions, traumatisms and ablative therapies of the native and transplanted kidney), the use of CT contrast media presents a high risk of contrast-induced nephropathy (i.e. in elderly people, subjects with comorbidities and those with renal dysfunction), while gadolinium-based RM contrast agents are contraindicated for the risk of nephrogenic systemic fibrosis (i.e. in patients with severe renal dysfunction). In these situations, CEUS may be a viable alternative, however, as any technique associated with the infusion of pharmacological substances, the potential advantages and risks of CEUS should be critically evaluated. In this regard, the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) has published the guidelines for the use of CEUS for the kidney imaging and the International Contrast Ultrasound Society (ICUS) has been recently founded. The aim of this review is to offer an updated overview of the potential applications of CEUS in nephrology, reporting some indications and possible risks associated to its use.
- An easy test but a hard decision: ethical issues concerning non-invasive prenatal testing for autosomal recessive disorders. [JOURNAL ARTICLE]
- Eur J Hum Genet 2014 Nov 5.
Prenatal testing based on cell-free fetal DNA in maternal serum is now possible for specific monogenic conditions, and studies have shown that the use of non-invasive testing is supported by prospective parents and health professionals. However, some ethical issues have been raised concerning informed consent and paternal rights. The objective of this study was to explore ethical aspects of the use of non-invasive prenatal diagnostic testing for autosomal recessive disorders. We used a qualitative cross-sectional design, based on Thematic Analysis, and recruited 27 individuals of reproductive age who were carriers of one of four conditions: thalassaemia, sickle cell disease, cystic fibrosis or spinal muscular atrophy. Data were collected via focus groups or interviews. Participants were aware of the potential for such tests to be viewed as routine and suggested that obtaining written consent and allowing time for consideration is needed to facilitate autonomous choice and informed consent. All participants felt that mothers should be able to request such tests, but fathers who declined carrier testing should be made aware that fetal test results may reveal their status. We suggest that a written record of consent for non-invasive prenatal diagnosis should be used as a standard to help reinforce the serious nature of the test results. Where the father's carrier status could be revealed through fetal testing, he should be made aware of this before the results are available. Health professionals should discuss with the pregnant woman the best way to manage unsought information about the father's carrier status to minimise family disruption.European Journal of Human Genetics advance online publication, 5 November 2014; doi:10.1038/ejhg.2014.238.
- Prenatal and preconception population carrier screening for cystic fibrosis in Australia: Where are we up to? [JOURNAL ARTICLE]
- Aust N Z J Obstet Gynaecol 2014 Oct 28.
To describe prenatal and preconception population carrier screening for cystic fibrosis (CF) in Australia and consider progress towards establishing a universal program.Medline and Embase databases (1989-2013) were searched for all publications with Australian data. Existing programs for CF carrier screening in Australia were reviewed and professional peak body websites accessed to determine recommendations.Twenty-two studies met the inclusion criteria. Key stakeholder groups believe that prenatal and preconception carrier screening for CF should be available. Health-economic analyses support that CF carrier screening can be cost-effective. There are small programs for CF carrier screening, in Victoria, New South Wales and Queensland. The Human Genetics Society of Australasia (HGSA) specifically recommend that screening be offered to women and couples planning a pregnancy and in the early stages of pregnancy. Other peak bodies indirectly endorse the availability of CF carrier screening. Barriers to screening include not being offered screening, the cost of testing, inequity of access and an incorrect perception that not having a family history of CF lowers risk.There is support for prenatal and preconception CF carrier screening by the community, health professionals and peak professional bodies in Australia. The barriers to development of a national screening program could be overcome with greater physician engagement and government support.In the interest of equity, government funded testing should be routinely offered to all pregnant women and couples planning a pregnancy.