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.

Non-classic cystic fibrosis associated with D1152H CFTR mutation.

BACKGROUND: Limited knowledge exists on phenotypes associated with the D1152H cystic fibrosis transmembrane conductance regulator (CFTR) mutation. METHODS: Subjects with a D1152H allele in trans with another CFTR mutation were identified using the French Cystic Fibrosis Registry. Phenotypic characteristics were compared with those of pancreatic insufficient (PI) and pancreatic sufficient (PS) cystic fibrosis (CF) subjects in the Registry (CF cohort). RESULTS: Forty-two subjects with D1152H alleles were identified. Features leading to diagnosis included chronic sinopulmonary disease (n = 25), congenital absence of the vas deferens (n = 11), systematic neonatal screening (n = 4), and genetic counseling (n = 2). Median age at diagnosis was 33 [interquartile range (IQR, 24-41)] years in D1152H subjects. Median sweat chloride concentrations were 43.5 (39-63) mmol/l in D1152H subjects and were markedly lower than in PI and PS CF subjects (p < 0.05). Bronchiectasis was present in 67% of D1152H subjects, but Pseudomonas aeruginosa colonization and pancreatic insufficiency were present in <30% of subjects. Estimated rates of decline in forced expiratory volume in 1 s (FEV(1)) were lower in D1152H subjects vs PI CF subjects (p < 0.05). None of the D1152H subjects identified since 1999 had died or required lung transplantation. CONCLUSIONS: When present in trans with a CF-causing mutation, D1152H causes significant pulmonary disease, but all subjects had prolonged survival.

New surfactant protein C gene mutations associated with diffuse lung disease.

BACKGROUND: Mutations in the surfactant protein C gene (SFTPC) have been recently associated with the development of diffuse lung disease, particularly sporadic and familial interstitial lung disease (ILD). OBJECTIVE: We have investigated the prevalence and the spectrum of SFTPC mutations in a large cohort of infants and children with diffuse lung disease and suspected with surfactant dysfunction. METHOD AND RESULTS: 121 children were first screened for the common SFTPC mutation, p.Ile73Thr (I73T). Ten unrelated patients were shown to carry this mutation. The I73T mutation was inherited in six cases, and appeared de novo in four. The 111 patients without the I73T mutation were screened for the entire coding sequence of SFTPC. Of these, eight (seven unrelated) subjects were shown to carry a novel mutant allele of SFTPC. All these seven new mutations are located in the BRICHOS domain except the p.Val39Ala (V39A) mutation, which is in the surfactant protein C (SP-C) mature peptide. CONCLUSIONS: Our results confirm that SFTPC mutations are a frequent cause of diffuse lung disease, and that I73T is the most frequent SFTPC mutation associated with diffuse lung disease.

[Respiratory function testing in infants: recommendations on normal values]. / EFR du nourrisson: le point sur les valeurs normales.

The present document is being produced on behalf of the French Society of the Physiology Task Force on standards for Infant Respiratory Function Testing whose aim is to provide guidelines for good laboratory practices according to the latest international recommendations. Application of such recommendations could be of particular value when attempting to develop standardized protocols in the scope of multi-centre trials. The first part resume these recommendations about apparatus, acquisition system and software for Infant Respiratory Function Testing. The second part focuses on physiological principles and practical considerations: calibration procedure, infant conditioning, tidal breathing measurements, and occlusion techniques for assessing passive respiratory mechanics, plethysmographic measurements of lung volume and airway resistance and forced expiratory flows measurements. The major problem when collecting lung function data is that of predicted values. Valid reference data, set up according to these recommendations, are, to date, still to be established. The last part of the document provides a review of the literature concerning infant respiratory function reference data and a resume of the most used of them. This document will clearly need to be updated regularly in response to advances in knowledge in this field.

[Exercise capacity in children with mild sleep-disordered breathing]. / Capacité physique de l'enfant présentant un syndrome d'apnée du sommeil léger.

INTRODUCTION: While the association between sleep-disordered breathing (SDB) and low physical activity has been reported in children, little information is available on the impact of SDB on exercise capacity. The aim of this study was to assess exercise capacity in children with SDB in order to estimate the relevance of exercise training intervention. METHODS: Twelve young patients with suspected SDB matched with 11 presumably healthy subjects of same age range (aged 13±0.5yr) were investigated. Both groups underwent physical activity assessment, full night polysomnography, incremental and all-out exercise tests. RESULTS: The respiratory disturbance index was higher in the patient group (4.6±4.7 vs 0.8±0.6; P=0.02). Children with SDB had lower VO2max (32.0±9.9 vs 42.3±5.7mL.kg-1.min-1, P=0.007) and lower peak power (8.6±3.4 vs 11.8±1.9W.kg-1, P=0.009). A significant correlation between VO2max and weekly physical activity only was found in the SDB group (P=0.005). CONCLUSION: Mild SDB may be associated with impairment of both aerobic and anaerobic exercise capacity in children, related to poor physical activity. Exercise training could bring clinical benefit in this population.

[Cystic fibrosis: how to use pulmonary function tests]. / Mucoviscidose: du bon usage des explorations fonctionnelles respiratoires.

INTRODUCTION: Neonatal screening for cystic fibrosis (CF) leads to early dedicated specialist care for all patients. BACKGROUND: Pulmonary function tests (PFT) are mandatory for routine monitoring of CF patients. The aim of this article is to review the current guidelines for PFTs in CF, particularly the type of test, the age and the clinical status of the patient. VIEWPOINT: The regular use of spirometry is generally accepted. Many other tests are used but their clinical value in the routine follow-up of CF patients remains to be established. CONCLUSION: Further efforts should be made to evaluate the value of PFTs in CF, particularly in very young children.

[Physical fitness in children with asthma]. / Aptitude à l'effort de l'enfant asthmatique.

The exercise limitation in a child with asthma is the result of several factors: the lack of ventilatory reserve, muscle deconditioning, and cardiac limitation. The severity of the airway obstruction is a major determinant of physical fitness. Aerobic and anaerobic fitness are equally affected. Both types of fitness can be improved by specific training programs.

Anaerobic fitness in children with asthma: adaptation to maximal intermittent short exercise.

Nineteen asthmatic boys (aged 13.4 years, 25-75 percentile: 11.5-15.1 years) performed short bouts of maximal exercise (force-velocity test) to test their anaerobic fitness and tolerance of maximal anaerobic exercise. Fourteen healthy boys (aged 13.9 years, 25-75 percentile: 11.6-15.7 years) matched for anthropometric characteristics including lean body mass (LBM), pubertal stage, and weekly physical activity formed a control group. The maximal anaerobic power (W(ana)) was measured during the force-velocity test. The maximal oxygen uptake (V'(O2max)) was assessed during a standard graded exercise test. Pre- and post-exercise pulmonary function was measured by body plethysmography. The asthmatic children exhibited lower W(ana) than the control group (8.2 watt.kg(-1) LBM, 25-75 percentile: 7.55-10.6 vs. 11.3 watt.kg(-1) LBM, 25-75 percentile: 9.46-14.1; P = 0.01). V'(O2max) was also diminished in the asthmatic group (P = 0.01). Multiple stepwise regression models revealed that Tanner's score (P < 0.001) and the diagnosis of asthma (P < 0.01) were the best predictors of W(ana). In conclusion, a diminished anaerobic fitness could contribute to the overall exercise limitation in asthmatic children.

Wingate test performance in children with asthma: aerobic or anaerobic limitation?

To investigate the anaerobic capacity in children with bronchial asthma, eight male children with atopic asthma (age: 12 +/- 1.7 yr) and seven healthy control subjects (age: 12 +/- 1 yr) performed a 30-s all-out exercise test: the Wingate anaerobic test (WanT). Post-exercise plasma epinephrine (E), norepinephrine (NE), venous blood lactate (La), and blood pH levels were determined. Peak power (Ppeak), mean power (Pm), and total energy expenditure (Wtot) during the WanT were assessed. The relative importance of aerobic (WO2) and anaerobic (Wana) energy release during the WanT was also evaluated. In comparison with control subjects, the children with asthma exhibited lower Ppeak (W.kg-1): 6 +/- 1.14 vs 7.3 +/- 0.5, P < 0.05; lower Pm (W.kg-1): 4.7 +/- 0.8 vs 5.9 +/- 0.5, P < 0.05; and lower Wtot (Jg-1): 140.3 +/- 25 vs 176.9 +/- 19, P < 0.05. The relative contribution of WO2 (26%) and Wana (74%) to the Wtot was identical in both groups. Blood lactate and pH kinetics revealed significantly lower La values and less acidosis in the asthmatic group (P < 0.001). Lastly, E (pg.ml-1) concentrations were lower in the asthmatic group: 274.96 +/- 84.58 vs 901.28 +/- 604.76, P < 0.05. These results suggest a reduced anaerobic capacity in children with asthma. A diminished adrenergic response to exhausting exercise, leading to a decreased anaerobic glycolysis, could partly account for this phenomenon.

Ideal timing of thoracoscopic decortication and drainage for empyema in children.

BACKGROUND: Thoracoscopy may be required for resistant empyema in children. This study aimed to determine the advantages of thoracoscopy performed soon after diagnosis and its ideal timing. METHODS: Between 1996 and 2002, 21 children who had undergone thoracoscopy as an initial procedure or after failure of medical treatment were retrospectively reviewed. The study compared outcome of early thoracoscopy (fewer than 4 days after diagnosis) and that of later surgery. The 4-day limit was chosen for physiopathologic reasons (organization of pleuresia in 72 h). RESULTS: In the early thoracoscopy group, the findings showed shorter operative time (p = 0.03) and postoperative hospital stay (p < 0.05), fewer technical difficulties, fewer complications, and no recourse to other surgical procedures. CONCLUSIONS: Early thoracoscopy is greatly beneficial for children with empyema by shortening disease progression. An initial short trial of medical treatment for nonorganising empyema may be attempted on the condition that thoracoscopy not be delayed more than 4 days.

[Cardiac adaptation to muscular exercise in children after complete repair of tetralogy of Fallot]. / Adaptation cardiaque à l'exercice musculaire chez l'enfant après réparation complète de tétralogie de Fallot.

The aim of this study was to assess cardiac adaptation to muscular exercise in children operated for tetralogy of Fallot. Eight children with a history of tetralogy of Fallot were studied and compared with ten control children. The basal evaluation consisted of an electrocardiogram, spirometry in all cases. Chest X-ray and echocardiography in all operated children. A muscular exercise stress test with incremental load on a bicycle ergometer was carried out with measurement of the cardiac output by CO2 rebreathing (experimental method). Under resting conditions, the two groups were comparable with respect to anthropometrical parameters and respiratory function. The cardiovascular data confirmed the good postoperative results of the children with a history of tetralogy of Fallot; cardiothoracic index of 0.49 to 0.55; sinus rhythm on the electrocardiogram; right ventricular pressures within normal limits; residual instantaneous right ventricular-pulmonary artery pressure gradient less than 25 mmH. On exercise, there was no significant difference with respect to VO2max, maximal heart rate, maximal cardiac output and maximal ventilation. The relationship between cardiac output and oxygen consumption was linear in two groups: y = 8.17x + 1.95 in the control group, y = 8.57x + 2.82 in the operated children. The change in cardiac output on exercise was comparable in the two groups. These observations seemed to be related to the good postoperative haemodynamic result: absence of pulmonary sequellae and right ventricular dysfunction. Despite the normality of the results obtained in this series, exercise stress testing with analysis of cardiac and respiratory adaptation would seem to be necessary in the follow-up of children operated for tetralogy of Fallot to exclude a ventilatory or circulatory limitation.

[Association of severe bronchial disease (bronchial casts, bronchiectasis) and partial abnormal pulmonary venous drainage in 2 children with Turner's syndrome]. / Association d'une bronchopathie sévère (moules bronchiques, dilatation des bronches) et d'un retour veineux pulmonaire anormal partiel à un syndrome de Turner chez deux enfants.

UNLABELLED: The prevalence of cardiovascular malformation is high in Turner's syndrome. We report two cases of partial anomalous pulmonary venous drainage associated with a severe bronchial disease. CASE REPORTS: Case 1: a 5-year-old girl with monosomy X presented with acute respiratory failure. The chest X-ray showed an atelectasis of the left lower lobe. The patient improved following bronchoscopic removal of a bronchial cast. During hospitalization, an anomalous pulmonary venous drainage of the right lung was discovered. In spite of complete surgical repair of the cardiac malformation, several episodes of respiratory failure occurred several years after the operation. Case 2: a 9-year-old girl with monosomy X and coarctation of the aorta underwent pre-operative cardiac catheterization. She had a history of bronchiectasis, leading to a lobectomy. Her respiratory condition improved following surgery. A partial anomalous pulmonary venous return was discovered during the cardiac angiography. The coarctation was repaired surgically. The correction of the left-to-right shunt was not necessary. CONCLUSION: The partial anomalous pulmonary venous return is frequently reported in Turner's syndrome. The possible respiratory disease associated with this cardiac malformation is usually described as a consequence of the increase in pulmonary blood flow. Our two cases did not match this hypothesis.

[Flexible bronchoscopy in children. Experience at French centers of pediatric pneumology]. / La fibroscopie bronchique chez l'enfant. Expertise des centres français de pneumologie pédiatrique.

INTRODUCTION: Fibreoptic bronchoscopy (FB) is an important diagnostic examination in paediatric pulmonology. In 2002 the Paediatric Pulmonology and Allergy Club undertook a retrospective study to establish the current status of fibreoptic bronchoscopy among its members. METHODS: In 2001 sixty five paediatric pulmonologists carried out an average of 116 examinations (+/- 111) in 35 paediatric centres. FB was performed either in an operating theatre (15 centres), a dedicated bronchoscopy suite (6 centres) or an endoscopy suite shared with gastro-enterologists (7 centres). Other examinations were performed in areas dedicated to, or associated with intensive care. General anaesthesia was routinely used in 18 centres. The others used sedation including an equimolar mixture of oxygen and nitrous oxide in 14 centres. Ten centres performed less than 50 examinations, 12 between 51 and 100, 4 between 101 and 200 and 8 centres more than 200 in the year. Seventy two per cent of the children were less than 6 years old. The washing and disinfection procedures were manual in 20 centres and automatic in 15. RESULTS: Three principal indications were reported: persistent wheezing, suspicion of a foreign body and ventilatory difficulties. Cough, desaturation and fever were the most frequently reported side effects. CONCLUSIONS: This is the first survey in paediatric pulmonology in France. It shows a wide variation in the practice of fibreoptic bronchoscopy in children.

Cyanosis revealing hepatopulmonary syndrome in a child with dyskeratosis congenita.

We report the case of a 5-year-old child with dyskeratosis congenita who presented cyanosis and dyspnea at exertion. He had severe hypoxemia with elevated alveolar-arterial oxygen gradient in the setting of liver disease. Technetium-99m-labeled macroaggregated albumin scan showed abnormally high uptake in the brain, confirming hepatopulmonary syndrome.

[Materno-fetal infections caused by unusual germs. Apropos of 9 cases]. / Infections materno-foetales à germes inhabituels. A propos de neuf observations.

A retrospective study carried out from January 1981 through August 1988 identified nine cases of materno-fetal infections (Staphylococcus aureus, 1 case; Klebsiella pneumoniae, 3 cases; enterococcus, 3 cases; Hemophilus influenzae, 1 case; and Pneumococcus, 1 case) in six girls and three boys; four premature infants developed respiratory distress requiring mechanical ventilation. In four cases, maternal history found risk factors for infection. All patients developed circulatory failure and one had purulent meningitis. Diagnosis was confirmed upon recovery of the microorganism from a central sample in six cases; in three cases, only the peripheral cultures were positive but diagnosis was supported by the positive maternal history and by clinical findings. Bacterial species were not associated with specific clinical or biological features, but infections due to Hemophilus influenzae, Klebsiella pneumoniae and pneumococcus were particularly severe (two deaths and two infants with neurologic sequelae). In some studies, unusual microorganisms account for 46% of septicemias and 36% of purulent meningitis. Group D streptococci are the most common bacteria in this category and may account for 10% to 15% of early neonatal septicemias. Organism-specific features are analyzed on the basis of data from the literature. Concerning therapy, this epidemiologic aspect of materno-fetal infections complicates the choice of the initial antimicrobial agents; because third-generation cephalosporins are not effective on listeria and group D streptococci, we advocate more widespread use of the ureidopenicillins instead of ampicillin.

Cells and mediators from pharyngeal secretions in infants with acute wheezing episodes.

An acute wheezing episode is the most common feature of severe lower respiratory tract infection during infancy. Respiratory syncytial virus (RSV) is the major causative agent. In order to study inflammation during acute wheezing episodes in infants, we wanted to assess the feasibility and contribution of induction of pharyngeal secretions. We therefore compared inflammatory markers in the pharyngeal secretions of 27 infants suffering from acute wheezing episodes with an RSV infection (RSV+) and 18 infants suffering with acute wheezing episodes without RSV infection (RSV-). Pharyngeal secretions were recovered by physiotherapy using isotonic saline. The safety of the procedure was carefully checked. Pharyngeal secretions were homogenized with dithiothreitol. Total cells and eosinophils were counted and levels of eosinophil cationic protein (ECP) and histamine were measured. Induction of pharyngeal secretion was always well tolerated. Eosinophils were present in five RSV+ and seven RSV- patients. ECP levels were not significantly different between the groups. Histamine levels after protein adjustment were significantly increased in RSV+ patients (p<0.01) in comparison to RSV- patients. In this study, we have shown, that pharyngeal secretion can be safely recovered from infants suffering from acute wheezing episodes, and that it can be analysed for enumeration of inflammatory cells and measurement of inflammatory mediators.