Biomedical subjects

X Vilanova

Publications and source records attributed to X Vilanova.

16 recordsLinked to original sources

PubMed2007

Use of a MS-electronic nose for prediction of early fungal spoilage of bakery products.

A MS-based electronic nose was used to detect fungal spoilage (measured as ergosterol concentration) in samples of bakery products. Bakery products were inoculated with different Eurotium, Aspergillus and Penicillium species, incubated in sealed vials and their headspace sampled after 2, 4 and 7 days. Once the headspace was sampled, ergosterol content was determined in each sample. Different electronic nose signals were recorded depending on incubation time. Both the e-nose signals and ergosterol levels were used to build models for prediction of ergosterol content using e-nose measurements. Accuracy on prediction of those models was between 87 and 96%, except for samples inoculated with Penicillium corylophilum where the best predictions only reached 46%.

Aspergillus↗

PubMed2004

The composition and persistence of faecal coliforms and enterococcal populations in sewage treatment plants.

AIMS: The changes in structure and composition of faecal coliforms and enterococcal populations in sewage from different treatment plants, and the elimination of vancomycin- and erythromycin-resistant enterococci (VRE and ERE, respectively) in these treatment plants was analysed to determine any selective reduction. METHODS AND RESULTS: Faecal coliforms, enterococci, VRE, ERE and spores of sulphite-reducing bacteria were enumerated using standard methods. Samples were enriched where necessary in order to isolate antibiotic resistant strains. The structure and composition of these bacterial populations were determined by biochemical fingerprinting and clustering analysis. High diversity and similarity indexes were detected among all the bacterial populations in raw and treated sewage, independently of their origin and the treatment processes employed. Antibiotic resistant strains were detected in all sewage tested and no selective reduction was observed. CONCLUSIONS: The faecal coliforms and enterococci populations did not differ in the sewage samples studied. The vancomycin and erythromycin resistances of the enterococcal populations were similar in the sewage samples. Resistance to both antibiotics persisted after the treatment process independently of raw sewage flow, faecal origin or size of the human population contributing to sewage. However, sewage of mixed origin (human and animal) presented a lower similarity index for the two bacterial populations compared with that of the other human sewage analysed. SIGNIFICANCE AND IMPACT OF THE STUDY: Although a significant reduction in bacterial populations was observed, the persistence of VRE and ERE strains in the same proportions in sewage suggests that there is no selective elimination of bacterial populations during the treatment processes. The ability of antibiotic resistance strains to survive sewage treatment systems should be considered in certain water reuse programmes.

Anti-Bacterial Agents↗

PubMed2003

Comparison of enterococcal populations related to urban and hospital wastewater in various climatic and geographic European regions.

AIMS: Scarce knowledge about the distribution of enterococci species in wastewaters limits any statement on their reliability as faecal indicators or the implications of antibiotic resistance transmission by these organisms through the water cycle. Enterococci have been involved in nosocomial infections and the spreading of antibiotic resistance through the food chain. The species distribution of enterococci and the presence of resistant strains to vancomycin and erythromycin were analysed in more than 400 raw and treated urban wastewaters, surface waters receiving these treated wastewaters and hospital wastewaters from three European countries. METHODS AND RESULTS: A total of 9296 strains were isolated and biochemically phenotyped. The species identification was based on the comparison of biochemical profiles with those of more than 20000 enterococci isolates from an international study. The prevalence of enterococcal isolates resistant to erythromycin (ERE) and vancomycin (VRE) was also analysed. ERE strains were present in a high proportion in all the studied samples. VRE strains were also isolated in all studied countries despite the time elapsed since the use of antimicrobial glycopeptides in animal production was banned in the European Union. CONCLUSIONS: Enterococcus faecalis and Ent. faecium were the most abundant species in all the studied wastewaters. All the studied wastewaters demonstrated high diversity and similar population structure and composition. ERE and VRE isolates were detected in most of the wastewaters. SIGNIFICANCE AND IMPACT OF THE STUDY: Urban and hospital wastewaters are useful targets for the evaluation of the prevalence of ERE and VRE isolates in the environment. It appears that these bacteria could pass through wastewater treatment plants and be transferred to surface waters.

Cities↗

PubMed2002

Quantitative analysis of NO2 in the presence of CO using a single tungsten oxide semiconductor sensor and dynamic signal processing.

We demonstrate that NO2 can be quantitatively analysed in the presence of CO using a single tungsten oxide based resistive gas sensor. The working temperature of the sensor was modulated between 190 and 380 degrees C and its dynamic response to different concentrations of CO, NO2, and CO + NO2 mixtures was monitored. Either the fast Fourier transform (FFT) or the discrete wavelet transform (DWT) was used to extract important features from the sensor response. These features were then input to different (statistical and neural) pattern recognition methods. The species considered can be discriminated with a success rate higher than 90% using a Fuzzy ARTMAP or a radial basis function neural network. The concentrations of the gases studied can be accurately predicted, by using the DWT coupled to partial least squares (PLS) models. The correlation coefficients of the predicted versus real concentrations were 0.923, 0.870 and 0.866 for CO, NO2, and NO2 in CO + NO2 mixtures, respectively.

Journal Article↗

PubMed1982