Biomedical subjects

Gianluigi Cardinali

Publications and source records attributed to Gianluigi Cardinali.

9 recordsLinked to original sources

PubMed2006

Biodegradation of the fungicide iprodione by Zygosaccharomyces rouxii strain DBVPG 6399.

Iprodione is a contact fungicide used to control several pathogens such as Botrytis cinerea, Monilia, and Sclerotinia. This paper reports the ability of an iprodione-resistant strain of Zygosaccharomyces rouxii to degrade iprodione at a concentration of 1 mg L(-1). The yeast Z. rouxii was chosen also for its ability to grow at high osmolarity. Also of note is that in bioremediation situations and in the food industry such resistance could be important. The kinetic and metabolic behaviors of the fungicide in the media are described. The results show a new transformation pathway of iprodione by the yeast leading to the formation of N-(3,5-dichlorophenyl)-2,4-dioxoimidazoline, 3-isopropylhydantoin, and 3,5-dichloroaniline. These compounds were identified by 1H NMR, 13C NMR, and GC-MS analyses. This study provides a basis to employ yeast strains in biodegradation studies in relation to their ability in the disappearance and degradation of xenobiotics into simpler molecules.

Aminoimidazole Carboxamide↗

PubMed2006

General evidence supporting the hypothesis that Saccharomyces cerevisiae vaginal isolates originate from food industrial environments.

Saccharomyces cerevisiae strains isolated from pregnant women were identified and characterized by molecular techniques which disclosed a wide chromosomal variability and possible segregations due to sporulation. The morphological analysis showed that very few strains were able to sporulate and generate pseudohyphae, whereas none produced proteases, raising some doubts on the importance of these characters in strain pathogenicity. The analysis of ethanol production revealed that these strains are quite similar to those found in fermentative plants, suggesting a possible derivation from the food industrial environment. Since the absence of relevant amounts of sugar does not confer selective advantage to strong fermentative metabolisms, these findings suggest that a metabolic adaptation to the vaginal environment did not occur yet.

Adaptation, Physiological↗

PubMed2005

Pulsed field gel electrophoresis and random amplified polymorphic DNA molecular characterization of Ralstonia pickettii isolates from patients with nosocomial central venous catheter related bacteremia.

Over a period of 18 months 3 clusters of central venous catheter-related Ralstonia pickettii bacteremia occurred in 3 different units of the same hospital. In order to investigate the relatedness of the clinical isolates we studied 15 strains using pulsed-field gel electrophoresis (PFGE) and randomly amplified polymorphic DNA (RAPD) techniques. The combined analysis of the results obtained by these two methods led us to conclude that all the patients except one were infected by a single clone comprising two variants circulating in the units. Only one case was due to a different strain, probably originating outside the ward. PFGE and RAPD appear to be discriminatory techniques to study the clonal relationship among the isolates and can represent a good tool to perform the epidemiological investigation of an outbreak.

Bacteremia↗

PubMed2004

Correlations among measures of phenotypic and genetic variation within an oligotrophic asexual yeast, Candida sonorensis, collected from Opuntia.

Many descriptions of yeast species are based on a limited number of strains collected at one time from a single locale. Often, little is known of phenotypic or genotypic variation and covariation within species. We compare 36 strains of an asexual cactophilic yeast, Candida sonorensis, collected from Opuntia cacti. Comparisons were based on geographical distances between collection locales, responses to physiological assimilation and stress tests, random amplified polymorphic DNA (RAPD) profiles, partial Lage Subunit (LSU) rDNA sequences, relative DNA-DNA hybridization values, and electrokaryotypes. There was significant variation among strains in all types of data collected. Comparisons among the different data types found significant positive associations between RAPD profiles, geographical distances, physiologies, reassociation values, and electrokaryotypes. No significant associations were found between rDNA sequences and any other type of variation measured. Based on RAPD, reassociation, electrokaryotype, and physiological data, the 36 strains could be divided into two groups: those collected in West Texas (nine strains) and all others. RAPD data indicated that 10 (of 12) Australian strains also formed a distinct clade. The taxonomic and phylogenetic status of these clades is discussed. Evidence that new genotypes can sweep through large geographic areas is also discussed.

Candida↗

PubMed2003

Electrophoretic data classification for phylogenetics and biostatistics.

SUMMARY: This paper presents ClassMaker, a macro of MS Excel able to classify continuous data of molecular weight data as binary (1/0) values. The output is represented by a binary matrix, which can be introduced in every software application for phylogenetics or multivariate statistics. This application is designed in order to be a link between image analysis programs and statistical or phylogenetic applications, in order to produce a complete series of free programs able to carry out the complete analysis from the gel to the dendrogram. AVAILABILITY: ClassMaker is freely available from http://www.agr.unipg.it/cardinali/index.html, where a list of the URLs from which programs of image analysis, statistics and phylogenetics can be freely downloaded.

Algorithms↗

PubMed2003

Variability of HXT2 at the protein and gene level among the Saccharomyces sensu stricto group.

Variability of HXT2 at the protein and gene level was investigated among Saccharomyces sensu stricto and other yeast species. Results showed that the HXT2 gene is probably present in yeast genera other than Saccharomyces, suggesting that this gene is widely distributed in the yeast world. Chromosomal analyses indicated the stable location of HXT2 on the same chromosome and with the same copy number throughout the entire sensu stricto group. Results of the immunoblotting assay demonstrated that all strains tested (with the exception of S. cerevisiae DBVPG 6042) exhibited a lower level of Hxt2p expression than that shown by laboratory wild-type. Moreover, Hxt2p expression seems to reinforce the taxonomical differences between the two pairs of species (S. cerevisiae and S. paradoxus vs. S. pastorianus and S. bayanus) within the sensu stricto group of the genus of Saccharomyces that also reflect their different ecological niche.

Chromosomes, Fungal↗

PubMed2002

Multicenter comparison of three different analytical systems for evaluation of DNA banding patterns from Cryptococcus neoformans.

The enormous improvement of molecular typing techniques for epidemiological and clinical studies has not always been matched by an equivalent effort in applying optimal criteria for the analysis of both phenotypic and molecular data. In spite of the availability of a large collection of statistical and phylogenetic methods, the vast majority of commercial packages are limited by using only the unweighted pair group method with arithmetic mean algorithm to construct trees and by considering electrophoretic pattern only as migration distances. The latter method has serious drawbacks when different runs (separate gels) of the same molecular analysis are to be compared. This work presents a multicenter comparison of three different systems of banding pattern analysis on random amplified polymorphic DNA, (GACA)(4), and contour-clamped homogeneous electric field patterns from strains of Cryptococcus neoformans var. neoformans isolated in different clinical and geographical situations and a standard Saccharomyces cerevisiae strain employed as an outgroup. The systems considered were evaluated for their actual ability to(i) recognize identities, (ii) define complete differences (i.e., the ability to place S. cerevisiae out of the C. neoformans cluster), and (iii) estimate the extent of similarity among different strains. The ability to cluster strains according to the patient from which they were isolated was also evaluated. The results indicate that different algorithms do indeed produce divergent trees, both in overall topology and in clustering of individual strains, thus suggesting that care must be taken by individual investigators to use the most appropriate procedure and by the scientific community in defining a consensus system.

Algorithms↗

PubMedDate not supplied

Measure of species variability for a microbial taxonomy based on the relative resemblance.

The concept of species currently in use in microbial taxonomy is based on sex because derives from that developed in zoology and botany. The absence of sex as the only system to reproduce does not allow to use the hybridization as the test to assess the conspecificity of microbial strains, forcing microbial taxonomists to use relative resemblance among strains as the only tool to define microbial species and to classify new microorganisms. Relative resemblance can be intuitively defined as the situation in which two strains of the same species must be more similar than each of them with a strain of any other species. Unfortunately, there are several algorithms to define the similarity between two strains, but none can be used to estimate the average distance between several members of the same species. This paper describes the problems inherent with the definition of species without hybridization tests and proposes two algorithms for a standard estimation of the overall variability of a species with the data obtained from a sample of strains. These measures will allow the non-subjective determination of the overall similarity among members of the same species using results from both phenotypic and molecular analyses. Both algorithms are based on a bootsrapping procedure implemented by RHO and SMA, two software applications freely available from the internet. These applications allow an easy evaluation of parameters such as the overall variability and levels of confidence associated with the sample of strains and the panel of characters under study.

Animals↗

PubMedDate not supplied

Correlation among phenotypical and molecular techniques in comparing ascomycetous yeast type strains.

Different phenotypical or molecular techniques can be used to describe and classify microorganisms for taxonomic, phylogenetic or genetic purposes. In yeast taxonomy the official hierarchic classification, based on morphological and physiological characters, is used together with more convenient molecular techniques such as the DNA sequencing. The question on whether these procedures produce coherent classifications is critical both to interpret taxonomic data consistently and to outline species correctly. In this paper, a set of type strains from the major genera of the budding hemiascomycetes yeast is examined with a series of physiological and molecular techniques, widely employed in taxonomy, in order to compare the among-strains correlations obtained with different methods. Results showed that the level of correlation among different techniques is relatively low, showing that different classifications and species organization could be obtained with diverse approaches. This is particularly interesting, considering that the official description of the yeast species is based on characters different from those becoming increasingly popular in the routine identification.

Animals↗