CYSTIC FIBROSIS AND ANTIBIOTIC HYPERSENSITIVITY: PRESENT KNOWLEDGE AND PRACTICAL APPROACH.

Cystic fibrosis is one of the most common fatal genetic diseases (1 in 2500 births). The defect causing the disease is localized on the 7q31 gene, which codifies for the CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) transmembrane protein. CFTR is a chloride channel localized on the epithelial cells of the mucosa of the respiratory tract, pancreatic ducts, biliary tree, intestine, vas deferens and sweat glands. More than 2000 different mutations are currently known; some are prominent or relatively frequent, ranging from one population to another. The most frequent complications of cystic fibrosis are those affecting the bronchial tree. Patients suffer from recurrent lung infections, which involve a progressive loss of lung function. The pulmonary infections are frequent or chronic and limit the quality of life of patients. In addition to being enormously exposed to antibiotics, they have many more opportunities to develop hypersensitivity reactions to these molecules. Only a complete allergy work-up with a detailed analysis of the clinical history, skin tests and provocation test can show if the patient has actually experienced an allergic hypersensitivity reaction. Desensitization is to be considered as a treatment that may help patients benefit from antibiotic treatment in those cases in which they have a proven allergy to a certain molecule.

Prevalence and variability of siderophore production in the Achromobacter genus.

Achromobacter spp. are opportunistic pathogens of environmental origin increasingly isolated in patients with underlying conditions like cystic fibrosis (CF). Despite recent advances, their virulence factors remain incompletely studied, and siderophore production has not yet been investigated in this genus. The aim of this study was to evaluate the production of siderophores in a large collection of Achromobacter spp. and evaluate the variability according to the origin of the strain and species. A total of 163 strains were studied, including 128 clinical strains (CF and non-CF patients) and 35 strains of environmental origin. Siderophores were quantified by the liquid chrome azurol-sulphonate assay. Species were identified by nrdA gene-based phylogeny. Strains were assigned to 20 species, with Achromobacter xylosoxidans being the most represented (51.5% of strains). Siderophore production was observed in 72.4% of the strains, with amounts ranging from 10.1% to 90% siderophore units. A significantly higher prevalence of siderophore-producing strains and greater production of siderophores were observed for clinical strains compared with strains of environmental origin. Highly variable observations were made according to species: A. xylosoxidans presented unique characteristics (one of the highest prevalence of producing strains and highest amounts produced, particularly by CF strains). Siderophores are important factors for bacterial growth commonly produced by members of the Achromobacter genus. The significance of the observations made during this study must be further investigated. Indeed, the differences observed according to species and the origin of strains suggest that siderophores may represent important determinants of the pathophysiology of Achromobacter spp. infections and also contribute to the particular epidemiological success of A. xylosoxidans in human infections. IMPORTANCE: Achromobacter spp. are recognized as emerging opportunistic pathogens in humans with various underlying diseases, including cystic fibrosis (CF). Although their pathophysiological traits are increasingly studied, their virulence factors remain incompletely described. Particularly, siderophores that represent important factors of bacterial growth have not yet been studied in this genus. A population-based study was performed to explore the ability of members of the Achromobacter genus to produce siderophores, both overall and in relevant subgroups (Achromobacter species; strain origin, either clinical-from CF or non-CF patients-or environmental). This study provides original data showing that siderophore production is a common trait of Achromobacter strains, particularly observed among clinical strains. The major species, Achromobacter xylosoxidans, encompassed both one of the highest prevalence of siderophore-producing strains and strains producing the largest amounts of siderophores, particularly observed for CF strains. These observations may represent additional advantages accounting for the epidemiological success of this species.

Utility of the Etest GRD for detecting Staphylococcus aureus with reduced susceptibility to glycopeptides in cystic fibrosis patients.

Glycopeptide-intermediate S. aureus (GISA), particularly heterogeneous GISA (hGISA), remain difficult to detect in the routine practice of medical microbiology. Novel tools have been evaluated comparatively to the population analysis profile-area under the curve (PAP-AUC) reference method for detecting GISA/hGISA. Among them, the Etest GRD showed relatively high specificity (85.8-97%) and negative predictive value (97%) but lower sensibility (57-95%) and positive predictive value (30.8%). We investigated the utility of the Etest GRD for detecting GISA/hGISA among 180 strains isolated from 106 cystic fibrosis (CF) patients. Etest GRD was performed on all isolates, and those exhibiting a GISA/hGISA phenotype were further tested by PAP-AUC and other agar routine assays for GISA/hGISA detection. The Etest GRD allowed the detection of 15 GISA/hGISA strains, of which eight were confirmed by the reference method. Despite the 3.9% level of false positive results, the Etest GRD constitutes a useful routine tool for detecting GISA/hGISA overlooked by other routine assays, two strains being detected by the Etest GRD only. GISA/hGISA represented 7.7% of MRSA and 2.1% of MSSA, and were found in 4.7% of CF patients colonized/infected by S. aureus, which is the highest rate reported to date in this population.

Intragenomic and intraspecific heterogeneity of the 16S rRNA gene in seven bacterial species from the respiratory tract of cystic fibrosis patients assessed by PCR-Temporal Temperature Gel Electrophoresis.

16S rRNA gene-based cultivation-independent methods are increasingly used to study the diversity of microbiota during health and disease. One bias of these methods is the variability of 16S rRNA gene that may exist among strains of a same species (intraspecific heterogeneity) or between rrs copies in a genome (intragenomic heterogeneity). We evaluated the level of intraspecific and intragenomic 16S rDNA variability in seven species frequently encountered in respiratory tract samples in cystic fibrosis (CF). A total of 179 strains were subjected to V3 region 16S rDNA PCR-TTGE. Using this easy-to-perform and rapid method, different levels of V3 region rrs heterogeneity were demonstrated. No intraspecific and intragenomic rrs heterogeneity was demonstrated for Moraxella catarrhalis (n=16), Pseudomonas aeruginosa (n=31) and Streptococcus pneumoniae (n=14) showing a single PCR-TTGE band characteristic of the species. Low level of intraspecific heterogeneity was observed for Staphylococcus aureus (n=30), Stenotrophomonas maltophilia (n=29) and Achromobacter xylosoxidans (n=28), and 17%, 38% and 96% of these strains showed intragenomic heterogeneity (two to four different rrs copies), respectively. Haemophilus influenzae (n=31) displayed the higher level of intraspecific variability with 23 different PCR-TTGE patterns and 61% of the strains showed intragenomic rrs heterogeneity (two to four different rrs copies). Although only one hypervariable region of the 16S rRNA gene was explored, intraspecific and intragenomic rrs heterogeneity was frequently observed in this study and should be taken into consideration for a better interpretation of 16S rRNA gene-based diversity profiles in denaturing gels and to avoid any overestimation of the respiratory microbiota diversity in CF.

[Emerging bacteria in cystic fibrosis and non-cystic fibrosis bronchiectasis from a microbiologist's perspective]. / Bactéries émergentes dans la mucoviscidose et les dilatations des bronches hors mucoviscidose. Le point de vue du microbiologiste.

INTRODUCTION: Common major pathogens like Pseudomonas aeruginosa are identified in the airways of patients with cystic fibrosis (CF) and non-CF bronchiectasis. However, other opportunistic bacterial pathogens like Achromobacter xylosoxidans complex, Stenotrophomonas maltophilia and non-tuberculous mycobacteria are currently emerging in CF and are also reported in non-CF bronchiectasis. BACKGROUND: The emergence of opportunistic bacterial pathogens has been recognized in CF through annual national reports of sputum microbiology data. Despite common factors driving the emergence of bacteria identified in CF and non-CF bronchiectasis patients, bronchiectasis registries have been created more recently and no longitudinal analysis of recorded microbiological data is currently available in the literature, thereby preventing the recognition of emerging bacteria in patients with non-CF bronchiectasis. OUTLOOK: A longitudinal follow-up of microbiological data is still needed in non-CF bronchiectasis to identify emerging opportunistic bacterial pathogens. Homogeneity in practice of sputum microbiological examination is also required to allow comparative analysis of data in CF and non-CF bronchiectasis. CONCLUSION: Bacterial pathogens recognized as emerging in CF have to be more carefully monitored in non-CF bronchiectasis in view of their association with deterioration of the lung disease.

[Measurement of pulmonary inflammation in cystic fibrosis]. / Mesure de l'inflammation pulmonaire dans la mucoviscidose.

Lung inflammation is a pivotal phenomenon in the pathogenesis of cystic fibrosis. Inflammation can be measured and quantified within a research perspective, as well as in daily clinical practice. In this review paper, the "Inflammation Task Force" of the "Société Française de Mucoviscidose" has reviewed the literature regarding the various techniques currently available (bronchoalveolar lavage, sputum analysis, nasal wash and brushing, exhaled breath condensates, carbon monoxide and nitric oxide, and systemic measurements (plasma and urine)). The interpretation of all these determinations in children and adults is also discussed.

[National consensus regarding azithromycin use in cystic fibrosis]. / Consensus national sur la prescription de l'azithromycine dans la mucoviscidose.

AIM: To propose a formalized consensus agreement regarding the prescription of azithromycin in cystic fibrosis (CF). MATERIAL AND METHODS: Application of the Delphi method in 5 thematic fields: indications, contra-indications, dosage, precautions for use and treatment follow-up. RESULTS: Thirty identified French CF centers participated in the process on 49 (61%), which comprised 3 rounds. Experts validated azithromycin as a long-term anti-inflammatory agent in children aged over 6 years, presenting with the classical form of CF, irrespective of the bacteriological status of the patient (except for non-tuberculous mycobacteria). Azithromycin administration should not be routine in the milder forms of the disease, and avoided in the presence of severe hepatic or renal involvement. In children whose weight is below 40 kg, a strong consensus recommended a single daily oral dose, administered three times weekly. However, in adults, the level of agreement was weaker. Minimal duration of treatment is 6 months, after which the drug should be discontinued if no observable effect is noted on clinical parameters, exacerbation rate and/or FEV1. Clinical monitoring of treatment tolerance is recommended (nausea, diarrhea, skin rash, tinnitus, deafness, arthropathy), without increasing the frequency of surveillance of sputum bacteria. However, it is essential to monitor sputum for fungi (expectoration, Aspergillus, broncho-pulmonary allergic aspergillosis). CONCLUSION: This consensus statement defines an area for the prescription of azithromycin in CF, with the aim of better harmonization of its use.

[Anemia and limping in a vegetarian adolescent]. / Anémie et boiterie chez un adolescent végétalien.

UNLABELLED: A vegan diet in the child and adolescent can induce severe bone sequelae by rickets and osteomalacia and megaloblastic anemia by cobalamin deficiency. CASE REPORT: A 15-year-old adolescent was hospitalized because of lameness and pallor. The lameness was explained by femoral epiphysiolysis caused by rickets with severe hypocalcemia. The pallor, jaundice and splenomegalia were due to cobalamin-deficiency megaloblastic anemia. A prolonged supplemental diet with calcium, vitamins D and B12 as well as orthopedic treatment stabilized the bone lesions. The megaloblastic anemia was cured by parenteral cobalamin. The adolescent and his brother were victims of a diet imposed by a cult and a lack of care due to their parents refusing that a vegan diet was the cause of the deficient pathology. Penal proceedings led to the incarceration of the parents and to the placement of the children. COMMENTS: Deficiencies in calcium and vitamins D and B12 may be severe in a child's development with a vegan diet. This case report reveals the social and legal problems of an inappropriate diet in infancy imposed by parents who are followers of a fundamentalist church. Beyond the management of children in cults, health professionals have to prevent, screen and supplement the deficient diet.

[National consensus regarding the prescription of inhaled corticosteroids in cystic fibrosis]. / Consensus national sur les modalités de prescription des corticoïdes inhalés dans la mucoviscidose.

UNLABELLED: The conditions for the prescription of inhaled steroids (ISs) in cystic fibrosis (CF) are not well established. AIM: To propose a formalized consensus agreement regarding the prescription of ISs in this disease. MATERIAL AND METHODS: Application of the Delphi method in five thematic fields: indications, non-indications, dosage, precautions for use, and treatment follow-up. RESULTS: Thirty of forty-nine (61 %) reference CF centers in France participated in the process, which comprised three rounds. Experts strongly agreed that ISs are indicated in the presence of pulmonary manifestations with wheezing, personal history of atopy, and/or bronchial hyper-responsiveness. In contrast, ISs are not indicated as first-line therapy for allergic bronchopulmonary aspergillosis. Strong agreement was reached regarding the daily dose of ISs, which should be similar to what is given in asthma and adapted to control symptoms so as to prescribe the smallest possible dose. Increasing the frequency of bacterial and fungal sputum analyses and eye (cataract) assessments was not deemed necessary. However, in case of prolonged (>6months) use of high-dose ISs, monitoring bone mineral density and the hypothalamic-pituitary-adrenal axis, in particular if itraconazole is concomitantly prescribed, was recommended. CONCLUSION: This consensus statement defines a perimeter for the prescription of ISs in CF, with the aim of limiting their prescription (until new data are available).

Effectiveness of bacteriophages in the sputum of cystic fibrosis patients.

Bacteriophages have been shown to be effective for treating acute infections of the respiratory tract caused by antibiotic-resistant bacteria in animal models, but no evidence has yet been presented of their activity against pathogens in complex biological samples from chronically infected patients. We assessed the efficacy of a cocktail of ten bacteriophages infecting Pseudomonas aeruginosa following its addition to 58 sputum samples from cystic fibrosis (CF) patients collected at three different hospitals. Ten samples that did not contain P. aeruginosa were not analysed further. In the remaining 48 samples, the addition of bacteriophages led to a significant decrease in the levels of P. aeruginosa strains, as shown by comparison with controls, taking two variables (time and bacteriophages) into account (p = 0.024). In 45.8% of these samples, this decrease was accompanied by an increase in the number of bacteriophages. We also tested each of the ten bacteriophages individually against 20 colonies from each of these 48 samples and detected bacteriophage-susceptible bacteria in 64.6% of the samples. An analysis of the clinical data revealed no correlation between patient age, sex, duration of P. aeruginosa colonization, antibiotic treatment, FEV1 (forced expiratory volume in the first second) and the efficacy of bacteriophages. The demonstration that bacteriophages infect their bacterial hosts in the sputum environment, regardless of the clinical characteristics of the patients, represents a major step towards the development of bacteriophage therapy to treat chronic lung infections.

Development of a synchrotron biaxial tensile device for in situ characterization of thin films mechanical response.

We have developed on the DIFFABS-SOLEIL beamline a biaxial tensile machine working in the synchrotron environment for in situ diffraction characterization of thin polycrystalline films mechanical response. The machine has been designed to test compliant substrates coated by the studied films under controlled, applied strain field. Technological challenges comprise the sample design including fixation of the substrate ends, the related generation of a uniform strain field in the studied (central) volume, and the operations from the beamline pilot. Preliminary tests on 150 nm thick W films deposited onto polyimide cruciform substrates are presented. The obtained results for applied strains using x-ray diffraction and digital image correlation methods clearly show the full potentialities of this new setup.

New synthesis of royal jelly acid.

A new synthesis of (E)-10-hydroxy-2-decenoic acid (royal jelly acid) is described, starting from 8-bromo-1-octanol via condensation of malonic acid with 8-hydroxyoctanal or 8-acetoxyoctanal.