Hyaluronic acid (HA) has several clinical applications (aesthetic surgery, dermatology, orthopaedics and ophtalmology). Following recent evidence, suggesting antimicrobial and antiviral properties for HA, we investigated its effects on 15 ATCC strains, representative of clinically relevant bacterial and fungal species. The in vitro system employed allowed to assess optical density of broth cultures as a measure of microbial load in a time-dependent manner. The results showed that different microbial species and, sometimes, different strains belonging to the same species, are differently affected by HA. In particular, staphylococci, enterococci, Streptococcus mutans, two Escherichia coli strains, Pseudomonas aeruginosa, Candida glabrata and C. parapsilosis displayed a HA dose-dependent growth inhibition; no HA effects were detected in E. coli ATCC 13768 and C. albicans; S. sanguinis was favoured by the highest HA dose. Therefore, the influence of HA on bacteria and fungi warrants further studies aimed at better establishing its relevance in clinical applications.

The hyphal wall protein 1 (HWP1) gene of Candida albicans encodes for a fungal cell wall protein, required for hyphal development and yeast adhesion to epithelial cells; yet, its role in pathogenesis remains largely unknown. In the present study, we analyzed two C. albicans laboratory strains, the DAY286 (HWP1/HWP1) and the null mutant FJS24 (hwp1/hwp1) and six clinical isolates [3 harbouring the homozygous HWP1 gene (HWP1/HWP1) and 3 the heterologous gene (HWP1/hwp1)]. Biofilm production, fungal HWP1 mRNA levels and ultrastructural morphology were investigated; also, the susceptibility of these strains to microglial cells was evaluated, in terms of fungal damage and immune cell-mediated secretory response. When comparing the two laboratory strains, biofilm was produced to a similar extent independently on the genetic background, while the susceptibility to microglial cell-mediated damage was higher in the hwp1/hwp1 mutant than in the HWP1/HWP1 counterpart. Also, transmission electron microscopy revealed differences between the two in terms of abundance in surface adhesin-like structures, fungal cell wall shape and intracellular granules. When comparing the clinical isolates grouped according to their HWP1 genotype, reduced biofilm production and increased susceptibility to microglial cell-mediated damage occurred in the HWP1/hwp1 isolates with respect to the HWP1/HWP1 counterparts; furthermore, upon exposure to microglial cells, the HWP1/HWP1 isolates, but not the HWP1/hwp1 counterpart, showed enhanced HWP1 mRNA levels. Finally, both laboratory and clinical isolates exhibited reduced ability to stimulate TNFα and nitric oxide production by microglial cells in the case of heterozygous or null mutant HWP1 genotype. Overall, these data indicate that C. albicans HWP1 genotype influences pathogen morphological structure as well as its interaction with microglial cells, while fungal biofilm production results unaffected, thus arguing on its role as virulence factor that directly affects host mediated defences.

Aims: To generate protein microarrays by printing microbial antigens on slides to enable the simultaneous determination in human sera of antibodies directed against Toxoplasma gondii, rubella virus,...

The incidence of VVC by non- albicans Candida (NAC) species, such as C. parapsilosis , is increasing. Treatment failure is common in NAC-VVC because some species are resistant or poorly susceptible to the antifungal agents normally employed.

Allergy is estimated to be the sixth leading cause of chronic disease in the US, and the number of people exhibiting symptoms of an allergic response to various natural and synthetic compounds has increased dramatically in the last decade ( 1). The prevalence of food allergies is particularly evident in children; some reports estimate that the frequency of food allergies in infants is 2–5% ( 2). The identification of the specific IgE responsible for the clinical symptoms can be a costly and lengthy procedure. Various immunoassays, such as ELISA ( 3), the Radio Allergo Sorbent Test ( 4), and high-capacity solid-phase tests, e.g., the CAP system (Pharmacia) ( 5), are currently used in the diagnosis of allergies and have the inherent sensitivity and specificity to detect IgE in human serum. However, all of these assays are time-consuming, require large quantities of serum samples, and use poorly characterized antigen preparations. Moreover, none of the assays currently used in the diagnosis of allergies has the throughput to screen for the most common allergens, which are estimated to exceed 300.