Publications by authors named "Silvia Arancia"

Article Synopsis
  • - Shiga toxin-producing E. coli (STEC) of the O26 serogroup is a major cause of Hemolytic Uremic Syndrome (HUS) in children, particularly in Europe, with specific clones like Sequence Type (ST) 29 gaining prevalence since the 1990s.
  • - A study analyzing 144 O26 STEC strains from Italy (1989-2020) found that most belonged to ST21 or ST29 and revealed various virulence and antimicrobial resistance genes distributed among these strains.
  • - Hierarchical Clustering identified seven genetic clusters based on accessory virulence and plasmid features, showing that certain ST29 strains are closely related, demonstrating the genetic stability and diversity of these O
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Enteroinvasive (EIEC) cause intestinal illness through the same pathogenic mechanism used by spp. The latter species can be typed through genomic and phenotypic methods used for and have been proposed for reclassification within species. Recently the first appearance of a highly pathogenic EIEC O96:H19 was described in Europe as the causative agent of two large outbreaks that occurred in Italy and in the United Kingdom.

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  • * In a study conducted in 2015, 234 samples of swine caecal content were tested at Italian abattoirs, revealing the presence of stx genes in 52.1% of the samples.
  • * Out of the isolated STEC strains, 74.2% had the stx2a gene subtype, with others showing combinations of subtypes but none showed the eae gene, indicating that while pigs can carry certain STEC strains, they might not be the main source of human
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In February 2017 a case of Hemolytic-Uremic Syndrome (HUS) was reported to the National Registry of HUS in an adult living in Northern Italy. Stool specimens from the patient and his family contacts were collected and the analyses led to the isolation of a Locus of Enterocyte Effacement (LEE)-negative Shiga toxin 2 (Stx2)-producing Escherichia coli. The epidemiological investigations performed brought to collect fecal samples from the animals reared in a farm held by the case's family and a mixture of bovine and swine feces proved positive for Shiga toxin-producing E.

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Aspergillus species are the cause of invasive mold infections in immunocompromised patients: Aspergillus fumigatus, A. flavus and A. terreus account for most cases of invasive aspergillosis (IA).

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The widespread occurrence of vaginal candidiasis and the development of resistance against anti-fungal agents has stimulated interest in understanding the pathogenesis of this disease. The aim of our work was to characterize, in an animal model of vaginal candidiasis, the mechanisms that play a role in the induction of mucosal immunity against C. albicans and the interaction between innate and adaptive immunity.

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Objectives: It has been previously shown that the treatment with the two protease inhibitors APG12 and APG19 confers protection in a rat model of mucosal candidiasis; in this study, we examined whether these peptidomimetic inhibitors are also effective as a cream formulation in reducing Candida albicans vaginal infection.

Methods: These efficacy studies were performed in a rat model of estrogen-dependent rat vaginitis by C. albicans on both azole-susceptible and azole-resistant C.

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The in vitro screening of stereoisomeric bicyclic peptidomimetics towards SAP2 of Candida albicans revealed a constrained chemotype as aspartic protease inhibitor in the micromolar to nanomolar range. The results indicated that the acetal bridge may serve as a transition-state isostere, and that the right match between interactions with subsites and the orientation by hydrogen bonding with Gly85 is the main requisite for inhibitory activity. Molecular docking calculations suggested the bicyclic acetal scaffold to be capable of interacting with the two catalytic aspartic acids, thus resulting in good inhibitory activity with only two hydrophobic groups addressing the enzyme catalytic subsites.

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A novel vaccine (PEV7) consisting of a truncated, recombinant aspartyl proteinase-2 of Candida albicans incorporated into influenza virosomes was studied. This vaccine candidate generated a potent serum antibody response in mouse and rat following intramuscular immunization. Anti-Sap2 IgG and IgA were also detected in the vaginal fluid of rats following intravaginal or intramuscular plus intravaginal administration.

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Synthetic peptides with sequences identical to fragments of the constant region of different classes (IgG, IgM, IgA) of antibodies (Fc-peptides) exerted a fungicidal activity in vitro against pathogenic yeasts, such as Candida albicans, Candida glabrata, Cryptococcus neoformans, and Malassezia furfur, including caspofungin and triazole resistant strains. Alanine-substituted derivatives of fungicidal Fc-peptides, tested to evaluate the critical role of each residue, displayed unaltered, increased or decreased candidacidal activity in vitro. An Fc-peptide, included in all human IgGs, displayed a therapeutic effect against experimental mucosal and systemic candidiasis in mouse models.

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Background: The MP65 gene of Candida albicans (orf19.1779) encodes a putative β-glucanase mannoprotein of 65 kDa, which plays a main role in a host-fungus relationship, morphogenesis and pathogenicity. In this study, we performed an extensive analysis of a mp65Δ mutant to assess the role of this protein in cell wall integrity, adherence to epithelial cells and biofilm formation.

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The feasibility of using high-resolution melting analysis (HRMA) was examined for its rapid and simple detection of 5 clinically relevant Candida species (C. albicans, C. glabrata, C.

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Vulvovaginal candidiasis is a mucosal infection affecting many women, but the immune mechanisms operating against Candida albicans at the mucosal level remain unknown. A rat model was employed to further characterize the contribution of B and T cells to anti-Candida vaginal protection. Particularly, the protective role of vaginal B cells was studied by means of adoptive transfer of vaginal CD3(-) CD5(+) IgM(+) cells from Candida-immunized rats to naïve animals.

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Candida albicans isolates with different genomic background, designed as b and c karyotypes, have been previously shown to differentially modulate their response to macrophage candidacidal activity. While b-type isolates were susceptible to intracellular killing, strains with c karyotype survived upon internalization and were able to replicate inside macrophages. Furthermore, it was also shown that c type strains escape microglial cell mediated growth inhibition, suggesting that these strains form a more virulent cluster.

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Article Synopsis
  • * Two compounds were found to have in vitro inhibitory effects similar to a known inhibitor, pepstatin A, and were as effective as fluconazole in treating vaginal candidiasis.
  • * These compounds remained effective against a strain of Candida albicans that was resistant to fluconazole, supporting the idea that SAP2 could be a target for creating new antifungal drugs.
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This study analyzes the phenotype of vaginal dendritic cells (VDCs), their antigenic presentation and activation of T-cell cytokine secretion, and their protective role in a rat model of Candida vaginitis. Histological observation demonstrated a significant accumulation of OX62(+) VDCs in the mucosal epithelium of Candida albicans-infected rats at the third round of infection. We identified two subsets of OX62(+) VDCs differing in the expression of CD4 molecule in both noninfected and Candida-infected rats.

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Article Synopsis
  • - A new method was developed to detect and measure Candida albicans in biological samples like blood, urine, and serum using Real-Time PCR with specific primers.
  • - Two detection systems were utilized on the LightCycler platform: SYBR green dye with melting analysis and a 5'nuclease probe, both showing high specificity for C. albicans without affecting other Candida or Aspergillus species.
  • - The method proved to be very sensitive, detecting as little as 1 genome in urine and serum, though blood samples had a higher detection limit by ten-fold, and it was applied to patient sera for invasive candidiasis diagnosis.
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Highly active anti-retroviral therapies (HAART) with human immunodeficiency virus (HIV) protease inhibitors (PIs) or nonnucleoside reverse-transcriptase inhibitors (NNRTI) were compared for their effect on prevalence, aspartyl proteinase (Sap) production and the biotypes and anti-mycotic sequential susceptibility of Candida spp. isolates from the oral cavity in a longitudinal prospective study. HAART-PI, but not HAART-NNRTI strongly inhibited Sap expression in the oral cavity without exerting any consistent effect on the role of Candida spp.

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