The EUCAST EDef 9.3.2 procedure recommends visual readings of azole and amphotericin B MICs against
spp. Visual determination of MICs may be challenging. In this work, we aim to obtain and compare ...visual and spectrophotometric MIC readings of azoles and amphotericin B against
isolates. A total of 847
isolates (
= 828 and cryptic species
= 19) were tested against amphotericin B, itraconazole, voriconazole, posaconazole, and isavuconazole using the EUCAST EDef 9.3.2 procedure. Isolates were classified as susceptible or resistant/non-wild type according to the 2020 updated breakpoints. The area of technical uncertainty for the azoles was defined in the updated breakpoints. Visual and spectrophotometric (fungal growth reduction of >95% compared to the control, read at 540 nm) MICs were compared. Essential (±1 2-fold dilution) and categorical agreements were calculated. Overall, high essential (97.1%) and categorical (99.6%) agreements were found. We obtained 100% categorical agreements for amphotericin B, itraconazole, and posaconazole, and consequently, no errors were found. Categorical agreements were 98.7 and 99.3% for voriconazole and isavuconazole, respectively. Most of the misclassifications for voriconazole and isavuconazole were found to be associated with MIC results falling either in the area of technical uncertainty or within one 2-fold dilution above the breakpoint. The resistance rate was slightly lower when the MICs were obtained by spectrophotometric readings. However, all relevant
mutants were correctly classified as resistant. Spectrophotometric determination of azole and amphotericin B MICs against
isolates may be a convenient alternative to visual endpoint readings.
We aimed to assess the percentage of azole resistance in Aspergillus fumigatus in Spain.
Thirty participating Spanish hospitals stored all morphologically identified A. fumigatus sensu lato clinical ...isolates—regardless their clinical significance—from 15 February to 14 May 2019. Isolates showing azole resistance according to the EUCAST 9.3.2 methodology were molecularly identified and the cyp51A gene was studied in A. fumigatus sensu stricto isolates.
Eight hundred and forty-seven isolates from 725 patients were collected in 29 hospitals (A. fumigatus sensu stricto (n = 828) and cryptic species (n = 19)). Isolates were mostly from the lower respiratory tract (94.0%; 797/847). Only cryptic species were amphotericin B resistant. Sixty-three (7.4%) out of the 847 isolates were resistant to ≥1 azole(s). Azole resistance was higher in cryptic species than in A. fumigatus sensu stricto (95%, 18/19 vs. 5.5%, 45/828); isavuconazole was associated to the lowest number of non-wild type isolates. The dominant mechanism of resistance was the presence of TR34-L98H substitutions (n = 24 out of 63). Out of the 725 patients, 48 (6.6%) carried either cryptic species (n = 14) or A. fumigatus sensu stricto (n = 34; 4.7%) resistant isolates. Aspergillus fumigatus sensu stricto harbouring either the TR34-L98H (n = 19) or TR46/Y121F/T289A (n = 1) mutations were detected in patients in hospitals located at 7/24 studied cities.
Of the patients, 6.6% carry azole-resistant A. fumigatus sensu lato isolates in Spain. TR34-L98H is the dominant cyp51A gene substitutions, although its presence is not widespread.
Recent epidemiological surveillance studies have reported an increase in fungaemia caused by non-Candida albicans species, as well as a decrease in fluconazole susceptibility.
To evaluate changes in ...the epidemiology of fungaemia in Spain comparing data from a new surveillance epidemiological study conducted in 2009 with a previous study carried out from 1997 to 1999 (Pemán J, et al. Eur J Clin Microbiol Infect Dis. 2005).
From January 2009 to February 2010, 44 Spanish hospitals participated in a prospective multicentre fungaemia surveillance study to ascertain whether there have been changes in the epidemiology and fluconazole susceptibility. Susceptibility was determined by the colorimetric method Sensititre Yeast One. Demographic and clinical data and the first isolate of each episode were gathered.
A total of 1,377 isolates from 1,357 fungaemia episodes were collected, 46.7% from patients older than 64years and 8.6% from children less than 1 year old. C. albicans (44.7%), Candida parapsilosis (29.1%), Candida glabrata (11.5%), Candida tropicalis (8.2%), and Candida krusei (1.9%) were the most frequent species isolated. Distribution varied with the geographical area. C. albicans incidence has increased significantly in the last 10years in Cataluña (39.1 vs. 54.7%, P=0.03) and decreased in the Valencian Community (49.1 vs. 34.6%, P=0.002) and Extremadura (58.3 vs. 20%, P=0.01). Susceptibility to fluconazole was similar for all geographical areas, although resistance in C. albicans was ten times greater for patients aged more than 64years. The overall rate of fluconazole resistance (MIC > 32 mg/L) has decreased with respect to that obtained 10years ago (3.7 vs. 2.5%) mainly in C. albicans (3 vs. 1.6%).
In the last ten years, species distribution and fluconazole susceptibility have not significantly changed, although a lower rate of fluconazole resistance has been observed. Species distribution varies with hospital, hospitalization Unit and geographical area.
Molecular-based techniques reduce the delay in diagnosing infectious diseases and therefore contribute to better patient outcomes. We assessed the FilmArray blood culture identification (BCID) panel ...(Biofire Diagnostics/bioMérieux) directly on clinical specimens other than blood: cerebrospinal, joint, pleural and ascitic fluids, bronchoscopy samples and abscesses. We compared the results from 88 samples obtained by culture-based techniques. The percentage of agreement between the two methods was 75 % with a Cohen κ value of 0.51. Global sensitivity and specificity using the FilmArray BCID panel were 71 and 97 %, respectively. Sensitivity was poorer in samples with a low bacterial load, such as ascitic and pleural fluids (25 %), whereas the sensitivity for abscess samples was high (89 %). These findings suggest that the FilmArray BCID panel could be useful to perform microbiological diagnosis directly from samples other than positive blood cultures, as it offers acceptable sensitivity and moderate agreement with conventional microbiological methods. Nevertheless, cost-benefit studies should be performed before introducing this method into algorithms for microbiological diagnostics.
The main goal of this study was to accurately detect azole resistance in species of the Aspergillus fumigatus complex by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry ...(MALDI-TOF MS).
Identification of isolates (n = 868) was done with MALDI-TOF MS using both commercial and in-house libraries. To determine azole susceptibility, the EUCAST E.Def. 9.3.2 method was applied as the reference standard. Identification of resistant isolates was confirmed by DNA sequence analysis. Protein spectra obtained by MALDI-TOF MS were analysed to differentiate species within the A. fumigatus complex and to detect azole-resistant A. fumigatus sensu stricto isolates.
Correct discrimination of A. fumigatus sensu stricto from cryptic species was accomplished in 100% of the cases applying principal component analysis (PCA) to protein spectra generated by MALDI-TOF MS. Furthermore, a specific peak (4586 m/z) was found to be present only in cryptic species. The application of partial least squares (PLS) discriminant analysis allowed 98.43% (±0.038) discrimination between susceptible and azole-resistant A. fumigatus sensu stricto isolates. Finally, based on PLS and SVM, A. fumigatus sensu stricto isolates with different cyp51A gene mutations were correctly clustered in 91.5% of the cases.
MALDI-TOF MS combined with peak analysis is a novel tool that allows the differentiation of A. fumigatus sensu stricto from other species within the A. fumigatus complex, as well as the detection of azole-resistant A. fumigatus sensu stricto. Although further studies are still needed, the results reported here show the great potential of MALDI-TOF and machine learning for the rapid detection of azole-resistant Aspergillus fumigatus isolates from clinical origins.
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Background and objective
Secreted mucins play a key role in antibacterial defence in the airway, but have not previously been characterized in non‐cystic fibrosis (CF) bronchiectasis patients. We aim ...to investigate the relationship between secreted mucins levels and the presence of bacterial colonization due to potentially pathogenic microorganisms (PPM) in the airways of stable bronchiectasis patients.
Methods
Clinically stable bronchiectasis patients were studied prospectively at two centres. Patients with other pulmonary conditions were excluded. Spontaneous sputum was subject to bacterial culture, and secreted mucins (MUC2, MUC5AC and MUC5B) were measured in sputum supernatants by ELISA.
Results
A total of 50 patients were included. PPM were identified from sputum samples in 30 (60%), with Pseudomonas aeruginosa (n = 10) and Haemophilus influenzae (n = 10) as the most common PPM. There were no baseline differences among airway colonized and non‐colonized patients. Patients with airways colonized by PPM presented higher levels of airway MUC2. No differences in MUC5AC levels were found among groups, whereas MUC5B levels were undetectable. Patients with P. aeruginosa colonization expressed the highest levels of MUC2. High levels of MUC2 and MUC5AC are also correlated with disease severity using the Bronchiectasis Severity Index.
Conclusions
Airway MUC2 levels were higher in bronchiectasis patients colonized with PPM compared with those without airway colonization, especially in patients with P. aeruginosa. These findings suggest that airway‐secreted mucins levels may play a role in the pathogenesis of airway infection in non‐CF bronchiectasis.
Secreted mucins are important for airway defence. However, their role in airway bacterial colonization in non‐CF bronchietasis has not been studied previously. Our study demonstrates that airway MUC2 levels are higher in patients with non‐CF bronchiectasis and airway bacterial colonization, especially in those with severe disease and Pseudomonas aeruginosa.
Background
Azole resistance screening in Aspergillus fumigatus isolates can be routinely carried out by using azole‐containing plates (E.Def 10.2 method), that requires filtering conidial suspensions ...prior inoculum adjustment.
Objectives
We evaluated whether skipping the filtration step of conidial suspensions negatively influences the performance of the E.Def 10.2.
Patients/Methods
A. fumigatus sensu stricto isolates (n = 92), classified as azole‐susceptible or azole‐resistant according to the EUCAST microdilution E.Def 9.4 method, were studied. Azole‐resistant isolates had either wild type cyp51A gene sequence (n = 3) or the TR34‐L98H (n = 26), G54R (n = 5), TR46‐Y121F‐T289A (n = 1), F46Y‐M172V‐N248T‐D255E‐E427K (n = 1), F165L (n = 1) or G448S (n = 1) cyp51A gene substitutions. In‐house azole‐containing agar plates were prepared according to the EUCAST E.Def 10.2 procedure. Conidial suspensions were obtained by adding distilled water (Tween 20 0.1%). Subsequently, the suspensions were either filtered or left unfiltered prior to inoculum adjustment to 0.5 McFarland. Using microdilution as the gold standard, agreement, sensitivity and specificity of the agar plates inoculated with two inoculums were assessed.
Results
Agreements for the agar screening method with either unfiltered or filtered conidial suspensions were high for itraconazole (100%), voriconazole (100%) and posaconazole (97.8%). Sensitivity (100%) and specificity (98.2%) of the procedure to rule in or out resistance when unfiltered suspensions were used were also high. Isolates harbouring the TR34‐L98H, G54R and TR46‐Y121F‐T289A substitutions were detected with the modified method.
Conclusions
Unfiltered conidial suspensions does not negatively influence the performance of the E.Def 10.2 method when screening for A. fumigatus sensu stricto.