We investigated the possibility of cross-infection among cystic fibrosis patients in two Brazilian reference centers. Achromobacter xylosoxidans isolates (n ‫؍‬ 122) were recovered over a 5-year period from 39 patients. Isolates were genetically heterogeneous, but one genotype was present in 56% of the patients, suggesting that cross-infection may have occurred.

No abstract

BackgroundPulmonary deterioration after B.cepacia complex (BCC) colonization has a heterogeneous pattern. The aim was to investigate the clinical outcome of BCC colonization in CF patients chronically colonized with P. aeruginosa.MethodsCF patients chronically colonized with P. aeruginosa were divided into three groups: intermittent (I), chronic (II) and no colonization (III) with BCC. Body mass index (BMI) percentile and spirometric parameters were analyzed at three different times in each group.ResultsFifty-six patients chronically colonized with P. aeruginosa were included. Of these, 27 also had evidence of BCC colonization (13 intermittent and 14 chronic). BMI percentile was significantly lower among patients chronically colonized by both P. aeruginosa and BCC. Mean values of FEV1 and FVC % were also significantly lower in these patients, both at the time of chronic BCC colonization and 24 months forward.ConclusionsChronic BCC colonization is associated with significant loss of lung function. Lower BMI might be a risk factor for chronic BCC colonization, preceding these events.

No abstract

Cystic fibrosis (CF) is the most frequent life threatening autosomal recessive disease in white subjects. The primary cause of morbidity and mortality in children with CF is chronic pulmonary infection, mainly caused by Pseudomonas aeruginosa. The purpose of this study was to assess the value of the measurement of antibodies to P. aeruginosa in diagnosing lung infection by the bacteria in CF patients. We assessed P. aeruginosa antibody titers in CF patients from Rio de Janeiro, Brazil, using cell lysate antigens as well as recombinant PcrV, a Type III Secretion System protein. Sputum (more than 70% of the specimens) or oropharyngeal swabs were obtained whenever patients were regularly followed for their pulmonary disease. Blood samples were obtained with an average interval of 6 months for a period of 2 years. The ELISA cut-offs were assigned as the positive 95% confidence interval of the mean antibody levels from non-fibrocystic controls. Our data showed that most CF patients (81%) of whom were not chronically infected by P. aeruginosa (Groups I and II), had their first serology positive for rPcrV. Cell-lysate ELISA was able to detect P. aeruginosa antibodies before positive culture in the first serum sample of 44% of the patients from Groups I and II. When serum reactivity to rPcrV and cell lysate were combined, 94% of CF patients from Groups I and II (n = 16) had the first serology positive for P. aeruginosa over a mean time of 20 months before the first isolation of P. aeruginosa. In conclusion, longitudinal P. aeruginosa serology should become part of respiratory care follow-up, in conjunction with other lung parameter functions.

Achromobacter spp. are opportunistic pathogens increasingly recovered from adult patients with cystic fibrosis (CF). We report the characterization of 122 Achromobacter spp. isolates recovered from 39 CF patients by multilocus sequence typing, virulence traits, and susceptibility to antimicrobials. Two species, A. xylosoxidans (77%) and A. ruhlandii (23%) were identified. All isolates showed a similar biofilm formation ability, and a positive swimming phenotype. By contrast, 4·3% and 44·4% of A. xylosoxidans and A. ruhlandii, respectively, exhibited a negative swarming phenotype, making the swimming and swarming abilities of A. xylosoxidans significantly higher than those of A. ruhlandii. A. xylosoxidans isolates from an outbreak clone also exhibited significantly higher motility. Both species were generally susceptible to ceftazidime, ciprofloxacin, imipenem and trimethoprim/sulphamethoxazole and there was no significant difference in susceptibility between isolates from chronic or sporadic infection. However, A. xylosoxidans isolates from chronic and sporadic cases were significantly more resistant to imipenem and ceftazidime than isolates of the outbreak clone.

Knowledge about the virulence mechanisms of species from the Burkholderia cepacia complex (BCC) is still limited. The genomovar heterogeneity and production of different virulence factors are likely to contribute to the variation in the clinical outcome observed in BCC-infected cystic fibrosis (CF) patients. Therefore, in this study we investigated the genetic polimorphism, the presence of genetic makers associated with virulence and transmissibility in BCC, and the profile of exoenzyme production of 59 BCC isolates obtained from 59 CF patients attending the reference CF centre in Rio de Janeiro, Brazil. The DNA sequence analyses of the recA gene allowed us to identify 40 of these 59 BCC species as being B. cenocepacia, 9 as B. vietnamiensis, 6 as B. multivorans and 4 as B. ambifaria. The assessment of the bacterial genetic polymorphism by PFGE revealed that B. cenocepacia and the B. multivorans isolates belonged to four and two different PFGE profiles with prevalence of two clones, A and B, respectively. All B. vietnamiensis and B. ambifaria belonged to only one PFGE profile (J and E, respectively). None of the isolates exhibited the genetic markers cblA and BCESM, assessed by polymerase chain reaction. In contrast, the profile of enzymatic activity, assessed by phenotypic methods, differed among the BCC species: protease activity was detected only in B. cenocepacia and B. ambifaria isolates, whereas only B. vietnamiensis isolates produced hemolysin. Although the phospholipase C activity was similar among the different species, the level of lipase activity produced by B. multivorans was higher than in the other species. We speculate that the differential characteristics of exoenzyme production may account for the differences in the pathogenic potentials of each BCC species.

Objective: To compare HRCT findings in cystic fibrosis (CF) patients chronically colonized with Pseudomonas aeruginosa or Staphylococcus aureus using the modified Bhalla CT scoring system, as well as to evaluate intraobserver and interobserver reliability of the method. Methods: This was a retrospective cross-sectional study involving 41 CF patients, 26 of whom were chronically colonized with P. aeruginosa (Pa group), and 15 of whom were colonized with S. aureus (Sa group).Two independent radiologists evaluated the HRCT scans of these patients using the modified Bhalla CT scoring system in two different moments. Intraobserver and interobserver reliability was calculated using the intraclass correlation coefficient (ICC). Results: There was good intraobserver and interobserver agreement (ICC > 0.8). Scores were higher in the Pa group than in the Sa group for observer 1 (mean, 13.50 ± 3.90; median, 13.5 vs. mean, 5.00 ± 5.28; median, 3.0) and for observer 2 (mean, 11.96 ± 5.07; median, 12.0 vs. mean, 5.07 ± 5.65; median, 5.0). In addition, HRCT findings, such as bronchiectasis, bronchial wall thickening, mucus plugging, generation of bronchial divisions, and mosaic attenuation/perfusion pattern, were more prevalent in the Pa group. Conclusions: The modified Bhalla CT scoring system was reproducible and reliable for use in the evaluation of HRCT scans, allowing distinctions to be drawn between the two groups of patients under study. The higher scores in the Pa group provided evidence of greater pulmonary impairment in that group.Keywords: Cystic fibrosis; Tomography; Staphylococcus aureus; Pseudomonas aeruginosa. ResumoObjetivo: Comparar achados de TCAR em pacientes com fibrose cística (FC) colonizados cronicamente por Pseudomonas aeruginosa ou Staphylococcus aureus, empregando o escore de Bhalla modificado, e avaliar as confiabilidades intraobservador e interobservador do método. Métodos: Estudo transversal retrospectivo incluindo 41 pacientes portadores de FC, 26 dos quais colonizados cronicamente por P. aeruginosa (grupo Pa) e 15 por S. aureus (grupo Sa). Dois radiologistas analisaram independentemente em duas ocasiões, as imagens de TCAR desses pacientes e aplicaram o escore de Bhalla modificado. As confiabilidades intra e interobservador foram avaliadas segundo o coeficiente de correlação intraclasse (CCI). Resultados: Houve boa concordância intraobservador e interobservador (CCI > 0,8). Os resultados dos escores do grupo Pa foram mais elevados que os do grupo Sa para o observador 1 (média de 13,50 ± 3,90 e mediana de 13,5 vs. média de 5,0 ± 5,28 e mediana de 3,0) e para o observador 2 (média de 11,96 ± 5,07 e mediana de 12,0 vs. média de 5,07 ± 5,65 e mediana de 5,0). Alterações tomográficas, como bronquiectasias, espessamento das paredes brônquicas, formação de tampões mucosos, comprometimento de gerações de divisões brônquicas e padrão de atenuação em mosaico, foram mais prevalentes no grupo colonizado por P. aeruginosa. Conclusões: O escore de Bhalla modificado se mostrou reprodutível e confiável p...