Teresa Gervasi

Expression and delivery of an endolysin to combat Clostridium perfringens.

Clostridium perfringens is a cause for increasing concern due to its responsibility for severe infections both in humans and animals, especially poultry. To find new control strategies to treat C. perfringens infection, we investigated the activity and delivery of a bacteriophage endolysin. We identified a new endolysin, designated CP25L, which shows similarity to an N-acetylmuramoyl-l-alanine amidase domain and is distinct from other C. perfringens endolysins whose activity has been demonstrated in vitro. The cp25l gene was cloned and expressed in Escherichia coli, and the gene product demonstrated lytic activity against all 25 C. perfringens strains tested. The probiotic strain Lactobacillus johnsonii FI9785 was engineered to deliver the endolysin to the gastrointestinal tract. The integration of the nisRK two-component regulatory system from the Lactococcus lactis nisin A biosynthesis operon into the chromosome of L. johnsonii allowed constitutive expression of the endolysin under the control of the nisA promoter (PnisA), while the use of a signal peptide (SLPmod) led to successful secretion of the active endolysin to the surrounding media. The high specificity and activity of the endolysin suggest that it may be developed as an effective tool to enhance the control of C. perfringens by L. johnsonii in the gastrointestinal tract.

Nero d’Avola and Perricone cultivars: determination of polyphenols, flavonoids and anthocyanins in grapes and wines

Abstract In 2011 vintage, the evolution of monomer and total anthocyanins, as well as of total flavonoids and polyphenols of grapes and wine of Nero d’Avola and Perricone, varieties cultivated in Sicily, was studied. Anthocyanin profiles are commonly used for grapevine cultivar identification because it is currently accepted that this trait is closely related to their genetic characteristics. The concentration of Nero d’Avola and Perricone anthocyanins was determined by HPLC-DAD.

Study of quantitative and qualitative variations in essential oils of Sicilian Rosmarinus officinalis L.

In this study the chemical characterisation of 10 Sicilian Rosmarinus officinalis L. biotypes essential oils is reported. The main goal of this work was to analyse the relationship between the essential oils yield and the geographical distribution of the species plants. The essential oils were analysed by GC-FID and GC-MS. Hierarchical cluster analysis and principal component analysis statistical methods were used to cluster biotypes according to the essential oils chemical composition. The essential oil yield ranged from 0.8 to 2.3 (v/w). In total 82 compounds have been identified, these represent 96.7–99.9% of the essential oil. The most represented compounds in the essential oils were 1.8-cineole, linalool, α-terpineol, verbenone, α-pinene, limonene, bornyl acetate and terpinolene. The results show that the essential oil yield of the 10 biotypes is affected by the environmental characteristics of the sampling sites while the chemical composition is linked to the genetic characteristics of different biotypes.

Mercury accumulation in Mediterranean Fish and Cephalopods Species of Sicilian coasts: correlation between pollution and the presence of Anisakis parasites

Abstract The aim of this study was to investigate mercury accumulation in some species, caught in Mediterranean Sea, in the period between May and December 2015, and to compare it to the presence of Anisakis parasites. The samples were examined by direct mercury analyzer (DMA-80) for their Hg levels. The metal concentration was compared to the presence or the absence of Anisakis parasites. Significant differences in Hg concentration in analysed samples were observed. The low-infested fishes contained 1–6 larvae of parasites whereas the high-infested one had 7–83 larvae.

Complete genome sequence of ΦCP51, a temperate bacteriophage of Clostridium perfringens.

During sequencing of the genome of Clostridium perfringens strain 5147-97, a putative prophage was identified, located within a gene for a proposed flavodoxin oxidoreductase. Mitomycin C induction of this strain released a bacteriophage whose morphological features examined by electron microscopy indicated it belonged to the family Siphoviridae. This phage was hence designated as vB_CpeS-CP51. The 39,108-bp genome includes 50 predicted open reading frames (ORFs), including two that may affect sporulation, and two predicted tRNAs. To determine the ends of the prophage, PCR was performed using primers facing outwards from the proposed end genes. This confirmed the presence of a circularised genome in PEG-precipitated bacteriophage particles.

Production and extraction of astaxanthin from Phaffia rhodozyma and its biological effect on alcohol-induced renal hypoxia in Carassius auratus

The effect of astaxanthin (3,3′-dihydroxy-s-carotene-4,4′-dione) on alcohol-induced morphological changes in Carassius auratus, as an experimental model, was determined. The yeast Phaffia rhodozyma was used as a source of astaxanthin. The animals were divided into three groups for 30 days: one group was treated with ethanol at a dose of 1.5% mixed in water, the second one with EtOH 1.5% and food enriched with astaxanthin from P. rhodozyma, and the third was a control group. After a sufficient experimental period, the samples were processed using light microscopy and evaluated by histomorphological and histochemical staining, and the data were supported by immunohistochemical analysis, using a wide range of antibodies, such as calbindin, vimentin and alpha-smooth muscle actin. The results show that the alcoholic damage in the kidney led to hypoxia. In contrast, the group fed with astaxanthin from P. rhodozyma showed a normal morphological picture, with better glomeruli organisation and the presence of the area of filtration. Furthermore, the immunohistochemistry has confirmed these results.

Does the light influence astaxanthin production in Xanthophyllomyces dendrorhous

Astaxanthin (C40H52O4) is an important natural pigment that has considerable promising applications in human health. Until now, many efforts were made aimed to develop economically sustainable bioprocesses alternative to the chemical synthesis, to satisfy the increasing demand of this ketocarotenoid from feed, food and cosmetic industries. The extraction of natural astaxanthin from the yeast Xanthophyllomyces dendrorhous till now seems to be rather expensive if compared with chemically synthesized astaxanthin. In this article, astaxanthin production by Xanthophyllomyces dendrorhous under two different conditions was studied: a first effort was made using a conventional reactor while a second using an enlightened one. This research was aimed also to optimise astaxanthin production by testing the influence of the light and of some nutrient sources. From fermentation tests, an astaxanthin yield ranging about 970 µg g−1 was obtained after fed batch cultivation in the conventional reactor. In the enlightened reactor lower values, about 930 µg g−1, were found.

Monitoring of neonicotinoid pesticides in beekeeping

Abstract The decline of pollinating species is correlated to the extensive use of neonicotinoids against pest insects for crop protection. In this study, the concentrations of neonicotinoid insecticides were determined in honeybees, honeycomb and honey samples, collected in Spring 2015 (blooming period) from different areas in Sicily (IT), to carry out an evaluation of bees products’ safety and an overview of neonicotinoid contamination in beekeeping. The results obtained showed only the presence of clothianidin in bee samples and these concentrations don’t represent a risk for bees’ vitality and safety. The absence of residue in all honey samples, instead, showed the quality of bee products.

Adherence to the Mediterranean diet in a Sicilian student population

Abstract Since the last decades, socio-economic changes have a key role on eating habits affecting the nutritional status and health of people, in particular children and adolescents. The aim of this study was to compare the diet of student population both normal weight and overweight and obese in order to understand their eating habits by comparing the different diets of the student referring to the Mediterranean diet. The study comprised 337 Sicilian students aged 9 to 13 years, 96 in primary schools and 241 in secondary schools, respectively, in three Sicilian cities namely, Messina, San Piero Patti and Ragusa. The variables studied were height, weight, body mass index (BMI) and adherence to the Mediterranean Adequacy Index (MAI) diet quality indicator. Interestingly, the results highlighted 2.67 MAI mean value for normal weight students while 1.27 MAI mean value indicating a decreased adherence to the Mediterranean diet in overweight students.

PCB-126 effects on aryl hydrocarbon receptor, ubiquitin and p53 expression levels in a fish product (Sparus aurata L.)

Abstract The aim of the present study is to determine if Ahr ligands as PCB-126, a dioxin-like, might contribute to inhibition of the tumour suppressor p53 by promoting its degradation through proteasome-ubiquitin system (UPS). The findings show, in the presence of PCB-126, a significant increase in p53 immunoreactivity in fish compared to the control. Subsequently, there is a decrease in p53 immunoreactivity at 24 h which is maintained even at 72 h. There is also a slight decrease in ubiquitin immunoreactivity to 12 h compared to the control and a marked decrease to 24 and 72 h. It’s very important to underline as in this study we demonstrate a marked decrease in ubiquitin and p53 immunoreactivity at 24 and 72 h. Our result emphasise the need to deeply the role of this receptor in UPS regulation as potential therapeutic target for cancer treatment.