Emergence of livestock-associated MRSA isolated from cystic fibrosis patients: Result of a Belgian national survey.

BACKGROUND: This study aims to determine the prevalence and characteristics of Staphylococcus aureus in Belgian cystic fibrosis (CF) patients. METHODS: Non-duplicate respiratory samples from 510 CF-patients (2012-2013) were examined. One isolate per patient was analysed unless different phenotypes were recovered. Isolates were investigated for mecA/mecC, toxins presence, spa-typing, MLST and SCCmec-typing. Potential livestock-associated (LA) isolates were examined for their immune-evasion-cluster (IEC) genes. RESULTS: S. aureus (n = 380), including 41 small-colony variants (SCVs), were isolated from 66.7% patients. The prevalence of methicillin-resistant S. aureus (MRSA) colonization was 4.9%. Two MRSA isolates carried toxic shock syndrome toxin 1 (TSST-1). Most MRSA (65%) belonged to two nosocomial epidemic clones (CC5, CC8) widespread in Belgium. Methicillin susceptible S. aureus (MSSA) showed great genetic diversity. Five of 33 isolates belonging to potential LA-lineages were IEC negative, including three methicillin-resistant isolates, suggesting an animal origin. CONCLUSIONS: The MRSA-prevalence in Belgian CF-patients remained constant (2001-2013), but SCV-prevalence increased. Most MRSA belonged to health-care-associated clones. Three patients carrying LA-MRSA were found, requiring further investigation to determine the risk factors for LA-MRSA acquisition.

Achromobacter xylosoxidans induced bronchiolitis obliterans in cystic fibrosis.

We report a 12-year-old boy with progressive bronchiolitis obliterans caused by Achromobacter xylosoxidans (Ax) colonization after liver transplantation, resulting in a steep decline in lung function.

Metabolic disregulation in obese adolescents with sleep-disordered breathing before and after weight loss.

OBJECTIVE: Sleep-disordered breathing (SDB) is prevalent in obesity. Weight loss is one of the most effective treatment options. The aim was to assess the association of SDB and metabolic disruption before and after weight loss. DESIGN AND METHODS: Obese adolescents were included when entering an in-patient weight loss program. Fasting blood analysis was performed at baseline and after 4-6 months. Sleep screening was done at baseline and at follow-up in case of baseline SDB. RESULTS: 224 obese adolescents were included. Median age was 15.5 years (10.1-18.0) and mean BMI z-score was 2.74 ± 0.42. About 30% had SDB at baseline (N = 68). High-density lipoprotein (HDL)-cholesterol was associated with mean nocturnal oxygen saturation () (partial r = 0.21; P = 0.002). Aspartate aminotransferase (ASAT) and alanine aminotransferase were related with oxygen desaturation index (partial r = -0.15; P = 0.03 and partial r = -0.15; P = 0.02), but this became insignificant after correction for sex. After weight loss, 24% had residual SDB. Linear regression showed an association between ASAT and (partial r = -0.34; P = 0.002). There were no significant correlations between improvements in laboratory measurements and sleep parameters. HDL-cholesterol improved in relation with the decrease in BMI z-score. CONCLUSION: SDB at baseline was associated with higher levels of liver enzymes and lower HDL-cholesterol concentration. Improvements in sleep parameters were not associated with improvements in laboratory measurements.

The role of acceptance in psychological functioning in adolescents with cystic fibrosis: a preliminary study.

This study explored the role of acceptance in accounting for the heterogeneity in psychological functioning in adolescents suffering from cystic fibrosis. Thirty-four adolescents completed a battery of questionnaires assessing acceptance, anxiety, depression, and disability. Regression analyses revealed that acceptance had a significant and unique contribution in explaining adolescents' anxiety, depression, and disability beyond the effects of demographic variables and parameters of disease severity. Forced expiratory volume, a parameter of disease severity, had a unique contribution in explaining disability, but not in explaining anxiety and depression. Our results support the idea that accepting the limitations imposed by a chronic disease and readjusting life goals has a positive effect upon psychological functioning in adolescents with cystic fibrosis. Acceptance-based therapies might prove useful in promoting well-being in adolescents with cystic fibrosis.

National survey of molecular epidemiology of Staphylococcus aureus colonization in Belgian cystic fibrosis patients.

OBJECTIVES: Epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) is poorly defined in cystic fibrosis (CF) patients, and S. aureus detection may be hampered by the presence of small colony variants (SCVs). We conducted a multicentre survey to determine the prevalence of S. aureus and MRSA colonization in Belgian CF patients and characterize the phenotype and clonal distribution of their staphylococcal strains. METHODS: S. aureus isolated from CF patients attending nine CF centres were collected. Oxacillin resistance was detected by oxacillin agar screen and mecA PCR. Antibiotic susceptibility was tested by microdilution. MRSA strains were genotyped by PFGE and SCCmec typing and compared with hospital-associated MRSA strains. RESULTS: Laboratories used a diversity of sputum culture procedures, many of which appeared substandard. S. aureus was isolated from 275/627 (44%) CF patients (20% to 72% by centre). The prevalence of SCV colonization was 4%, but SCVs were almost exclusively recovered from patients in two centres performing an SCV search. Phenotypically, 14% of S. aureus isolates were oxacillin-resistant: 79% carried mecA and 19% were SCVs lacking mecA. The mean prevalence of 'true' MRSA colonization was 5% (0% to 17% by centre). By PFGE typing, 67% of CF-associated MRSA were related to five epidemic clones widespread in Belgian hospitals. CONCLUSIONS: This first survey of S. aureus colonization in the Belgian CF population indicated a diversity in local prevalence rates and in proportion of oxacillin-resistant and SCV phenotypes, probably related to variation in bacteriological methods. These findings underscore the need for standard S. aureus detection methods and MRSA control policies in Belgian CF centres.

Role of magnesium in the failure of rhDNase therapy in patients with cystic fibrosis.

BACKGROUND: In the management of cystic fibrosis (CF), rhDNase-I inhalation is widely used to facilitate the removal of the highly viscous and elastic mucus (often called sputum) from the lungs. However, an important group of CF patients does not benefit from rhDNase-I treatment. A study was undertaken to elucidate the reason for the failure of rhDNase-I in these patients and to evaluate strategies to overcome this. METHODS: The biochemical properties, physical properties, and degradation by rhDNase-I of sputum obtained from clinical responders and non-responders to rhDNase-I were compared, and the ability of magnesium to reactivate rhDNase-I in DNA solutions and in sputum was investigated. The effect of oral magnesium supplements on magnesium levels in the sputum of patients with CF was also examined. RESULTS: Sputum from clinical responders was extensively degraded in vitro on incubation with rhDNase-I, while sputum from clinical non-responders was not degraded: the median decrease in sputum elasticity in the two groups was 32% and 5%, respectively. Sputum from clinical responders contained significantly higher concentrations of magnesium than sputum from non-responders (2.0 mM v 1.3 mM; p = 0.020). Sputum that could not be degraded by rhDNase-I became degradable after preincubation with magnesium. The effect of magnesium on rhDNase-I activity was mediated through actin. Oral intake of magnesium enhanced the magnesium concentration in the sputum of CF patients. CONCLUSION: Increasing the magnesium concentration in sputum by, for example, oral magnesium supplements may be a promising new strategy to overcome the failure of rhDNase-I in patients with CF.

Epidemiology of Pseudomonas aeruginosa in a cystic fibrosis rehabilitation centre.

Pseudomonas aeruginosa is the leading pathogen in cystic fibrosis (CF) lungs. Since there is great concern about clonal spread in CF centres, this study examined the P. aeruginosa genotypes of colonised residents of a CF rehabilitation centre. The isolates from the sputum of 76 P. aeruginosa-colonised patients were genotyped by fluorescent amplified fragment length polymorphism on arrival and departure. A total of 71 different P. aeruginosa genotypes were identified from 749 isolates. Forty-nine patients had one genotype, 20 had two genotypes and seven had three. Forty-four patients had one or more genotypes in common with other patients (i.e. cluster types). Thirty-two patients were colonised by a single genotype not shared by any other patient. Thirty-eight of the 44 patients with a cluster type already carried their cluster type strain(s) on arrival. Patient-to-patient transmission could not be excluded for eight patients. For five of these, this infection was transient. None of the environmental P. aeruginosa isolates had a genotype similar to the patients' genotypes. In summary, most patients were colonised by only one or two P. aeruginosa genotypes and the risk of persistent patient-to-patient transmission was low during the study period (4%). Most patients with a cluster-type strain carried this strain on arrival, indicating that transmission could have happened in the past. No environmental contamination could be established.

Inhaled steroids compared with disodium cromoglycate in preschool children with episodic viral wheeze.

In school children with atopic asthma the beneficial effects of disodium cromoglycate (DSCG) and beclomethasone dipropionate (BDP) are well-established. In preschool children, wheezing is quite common, and in the majority of cases the symptoms are episodic and reported to be associated with viral infections rather than atopy. We compared the efficacy of regular treatment with DSCG and BDP for prevention of wheezing in preschool children. We were interested to establish whether regular treatment with inhaled anti-inflammatory drugs could lead to a decrease in bronchial responsiveness. In 15 patients (median age, 56 months; range, 43-66 months) bronchial responsiveness was assessed by measuring specific airway resistance (sRaw) during a histamine provocation test. The concentration of histamine eliciting a 100% increase in sRaw (PC100his) was determined. In a double-blind crossover study, patients inhaled either DSCG 10 mg three times a day or BDP 100 microg three times a day for 2 months. After a wash-out period, treatment was changed to BDP or DSCG, respectively. Daily peak flow measurements were carried out, and exacerbations were noted. PC100his was measured at the start and end of each treatment period. No significant decrease in bronchial responsiveness was seen (PC100his DSCG: before 1.3, after 1.66 mg/ml, Pvalue not significant; BDP: before 1.1 after 1.22 mg/ml, Pvalue not significant). Significantly higher morning peak flows were observed on BDP therapy (160 on BDP vs. 150 L/min on DSCG, P < 0.03). BDP treatment resulted in significantly fewer wheezing exacerbations (7 vs. 16, P < 0.005) compared with DSCG therapy. We conclude that in preschool children with episodic virally induced wheezing, BDP therapy was superior to DSCG aerosol treatments for the prevention of exacerbations of wheezing, although no significant effect on bronchial responsiveness was noted during either treatment protocol.

Burkholderia (Pseudomonas) cepacia and cystic fibrosis: the epidemiology in Belgium.

Burkholderia cepacia has become an increasingly recognized pathogen among cystic fibrosis (CF) patients and its potential role in declining pulmonary function or unexpected fatal outcome has caused widespread concern. Direct person-to-person transmission has been documented and a segregation policy of CF patients colonized with B.cepacia from non-colonized CF patients is widely adopted. Since this policy has a dramatic impact on social behaviour of CF patients it is imperative that clinical laboratories accurately isolate and identify B.cepacia in the respiratory secretions. In order to comprehend the epidemiology of B.cepacia in the Belgian CF population a multicentre study was conducted during a period of 1 year (March'93-February'94). B.cepacia was isolated in only 12 of 465 CF patients (2.6%). Routine biochemical tests identified these strains as authentic B.cepacia. However, the combined data from protein and DNA-DNA hybridization analyses revealed that the Belgian CF "B.cepacia" isolates showed patterns different from reference B.cepacia isolates and belong to 3 different, newly identified Burkholderia genomovars, but not to B.cepacia. Comparative analysis of the selective media used for recovery of these "B.cepacia" strains from respiratory secretions indicated that the commercial medium (Mast) containing polymyxin B and ticarcillin as the selective agents was the best and most user-friendly. Molecular typing of these Burkholderia isolates by arbitrarily-primed PCR (AP-PCR) and pulsed-field gel electrophoresis (PFGE) showed that spread of a single strain within a same centre occurred but the mode of transmission remains unknown; inter-centre spread of strains was not observed. Interestingly, neither colonization with a distinct or an epidemic strain (belonging to either of the three newly identified Burkholderia genomovars) nor colonization for a prolonged period of time, led to a rapid deterioration of lung function in these CF patients. It appears essential to determine the prevalence of these "new" Burkholderia genomovars in larger populations of CF patients and to evaluate their virulence and other features as this may have important clinical and practical implications.

Effect of administration of gamma-linolenic acid on the fatty acid composition of serum phospholipids and cholesteryl esters in patients with cystic fibrosis.

This study examined the effects of supplementing patients with cystic fibrosis daily for 4 weeks with 1,500 mg borage oil, containing 330 mg gamma-linolenic acid, on the fatty acid composition of serum phospholipids (PL) and cholesteryl esters (CE). Vital capacity and forced expiratory volume in 1 s were also measured before and after treatment. In serum PL the content of arachidonic acid (AA) increased and that of palmitic acid decreased significantly after borage oil administration. In serum CE dihomogamma-linolenic acid increased whereas docosahexaenoic acid decreased significantly. In this lipid class, AA and the sum of AA plus its precursor, dihomogamma-linolenic acid, increased significantly with the dose fed. A positive correlation was found between change in vital capacity and change in linoleic acid content of serum CE and AA content of serum PL.

Increase of long chain omega-3 fatty acids in the major serum lipid classes of patients with cystic fibrosis.

We studied the effects of supplementing patients with cystic fibrosis for 1 month with 3 g/day of a dietary supplement, containing 911 mg omega 3 fatty acids, on the fatty acid composition of serum cholesterol esters, free fatty acids, phospholipids and triglycerides. At the end of the supplementation period, the content of total omega 3 fatty acids was increased significantly in all lipid classes. The effect on individual omega 3 fatty acids depended on the fatty acid and lipid class studied, increased with the dose fed and decreased with the weight of the patient. One month after the end of the supplementation period, fatty acid levels had returned to pretreatment values. These results demonstrate that enrichment of serum lipid classes with omega 3 fatty acids is feasible in CF patients by dietary supplementation.

Immune complexes and Pseudomonas aeruginosa antibodies in cystic fibrosis.

Serum samples from 57 patients with cystic fibrosis were tested for the presence of IgG, IgA, IgM, IgE, and circulating immune complexes containing IgG, IgA, and IgM. Titres of class specific antibodies to Pseudomonas aeruginosa, and class specific antibodies to Ps aeruginosa in circulating immune complexes, were also measured. According to the Shwachman score the patients were divided into three clinical groups: group 1-moderate and severe disease, group 2-mild disease, and group 3-well. The results of the immunological investigations were correlated with the clinical state of the patients as assessed by the Shwachman score. Serum concentrations of IgG, IgA, and IgM were inversely correlated with the Shwachman score, but the differences between the groups were only significant for IgG and IgA. The same correlations were found for circulating immune complexes containing IgG and IgA. Antibodies to Ps aeruginosa could be detected in most of the patients' serum samples. IgA antibody specific to Ps aeruginosa was the most often raised, even in patients in group 3. It is therefore suggested that IgA antibody specific to Ps aeruginosa could be an early marker of colonisation by Ps aeruginosa and a sensitive measurement of infection with Ps aeruginosa in young children with cystic fibrosis. Moreover, in the circulating immune complexes, class specific antibodies to Ps aeruginosa were found in nearly half the patients. The highest titres of IgG and IgA antibodies specific to Ps aeruginosa in the circulating immune complexes were detected in the patients with the worst clinical state (group 1).

[The effect of swimming on the nasal passages and on tube function in children]. / De invloed van het zwemmen op de neusdoorgankelijkheid en de tubafunktie bij kinderen.

In two studies the authors want to confirm experimentally what is assumed in every day ENT-practice: otitis and sinusitis are not infrequent complications of swimming. The first study, involving 60 children with chronic non-specific lung diseases shows that swimming in a sea water pool increases the nasal airway resistance during two days. In the second study, performed in 32 normal children swimming in a chlorous pool, a negative relationship is found between the number of days after the swimming and the increased nasal airway resistance. Probably other factors also play a part in this phenomenon. Due to the too small number of children showing an otitis media with effusion, the influence of swimming on the function of the Eustachian tube could not be determined.