Tania Wrobel Folescu

Achromobacter xylosoxidans: Characterization of Strains in Brazilian Cystic Fibrosis Patients

ABSTRACT 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.

Panton-Valentine leukocidin (PVL) gene carriage among Staphylococcus aureus strains with SCCmec types I, III, IV, and V recovered from cystic fibrosis pediatric patients in Brazil

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) is increasing in patients with cystic fibrosis (CF). We report a molecular characterization, antimicrobial resistance, and Panton-Valentine leukocidin (PVL) toxin gene detection of MRSA strains from 28 Brazilian pediatric CF patients (1 strain per patient). A significant proportion (50%) of MRSA SCCmec IV isolates was observed. Nearly half of MRSA strains harboring the PVL genes distributed in all SCCmec types detected. Multilocus sequence typing (MLST) analyses showed majority (57.1%) of the isolates belonged to known epidemic lineages, such as UK/EMRSA-3, Pediatric/USA 800, Southwest Pacific clone, and Brazilian/Hungarian clone. To our knowledge, this is the first Brazilian study of molecular epidemiology based on MLST and SCCmec typing and the first description of PVL genes in MRSA from CF patients.

Escore tomográfico em pacientes com fibrose cística colonizados por Pseudomonas aeruginosa ou Staphylococcus aureus

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.

Influence of biofilm formation in the susceptibility of Pseudomonas aeruginosa from Brazilian patients with cystic fibrosis.

Ferreira AG, Leão RS, Carvalho‐Assef APD, Folescu TW, Barth AL, Marques EA. Influence of biofilm formation in the susceptibility of Pseudomonas aeruginosa from Brazilian patients with cystic fibrosis. APMIS 2010; 118: 606–12.

Low‐level resistance and clonal diversity of Pseudomonas aeruginosa among chronically colonized cystic fibrosis patients

A prospective study was conducted in Brazil to evaluate antimicrobial resistance patterns and molecular epidemiology of Pseudomonas aeruginosa isolates from cystic fibrosis (CF) patients with chronic lung infection. All isolates were obtained between May 2009 and June 2010 from 75 patients seen in four reference centers in Brazil: HCPA (20 patients) and HEOM (15 patients), located in southern and northeastern Brazil, respectively; IFF (20 patients) and HUPE (20 patients), both in southwestern Brazil. Antimicrobial susceptibility testing, PCR for detection of carpapenemases, and pulsed‐field gel electrophoresis (PFGE) were performed in 274 isolates. A total of 224 PFGE types were identified and no clones were found circulating among the centers or within the same center. Despite the chronic infection, most patients were colonized by intermittent clones. Only three patients (4%) maintained the same clone during the study. The resistance rates were lower than 30% for the majority of antimicrobials tested in all centers and only 17% of isolates were multiresistant. Isolates (n = 54) with reduced susceptibility to imipenem and/or meropenem presented negative results for blaSPM‐1, blaIMP−1, blaVIM, and blaKPCgenes. Our results indicate an unexpected low level of antimicrobial resistance and a high genotypic diversity among P. aeruginosa from Brazilian chronic CF patients.