Effect of a UV-C Automatic Last-Generation Mobile Robotic System on Multi-Drug Resistant Pathogens.

BACKGROUND: Healthcare-associated infections caused by multi-drug resistant (MDR) pathogens are associated with increased mortality and morbidity among hospitalized patients. Inanimate surfaces, and in particular high-touch surfaces, have often been described as the source for outbreaks of nosocomial infections. The present work aimed to evaluate the efficacy of a last-generation mobile (robotic) irradiation UV-C light device R2S on MDR microorganisms in inanimate surfaces and its translation to hospital disinfection. METHODS: The efficacy of R2S system was evaluated in environmental high-touch surfaces of two separate outpatient rooms of Perugia Hospital in Italy. The static UV-C irradiation effect was investigated on both the bacterial growth of S. aureus, MRSA, P. aeruginosa, and K. pneumoniae KPC and photoreactivation. The antimicrobial activity was also tested on different surfaces, including glass, steel, and plastic. RESULTS: In the environmental tests, the R2S system decreased the number of bacteria, molds, and yeasts of each high-touch spot surface (HTSs) compared with manual sanitization. UV-C light irradiation significantly inhibits in vitro bacterial growth, also preventing photoreactivation. UV-C light bactericidal activity on MDR microorganisms is affected by the type of materials of inanimate surfaces. CONCLUSIONS: The last-generation mobile R2S system is a more reliable sanitizing procedure compared with its manual counterpart.

Resveratrol depolarizes the membrane potential in human granulosa cells and promotes mitochondrial biogenesis.

OBJECTIVE: To study the biological effects of resveratrol on the growth, electrophysiology, and mitochondrial function of human granulosa cells (h-GCs). DESIGN: Preclinical study. SETTING: Electrophysiology laboratory and in vitro fertilization unit. PATIENT(S): This study included h-GCs from seven infertile women undergoing assisted reproductive techniques. INTERVENTION(S): Human ovarian Granulosa Cell Tumor (GCT) cell line COV434 and h-GCs obtained after oocyte retrieval were cultured in the absence or presence of resveratrol. MAIN OUTCOME MEASURE(S): Granulosa cells were evaluated for cell viability and mitochondrial activity. Electrophysiological recordings and evaluation of potassium current (IKur) and Ca2+ concentration were also performed. RESULT(S): Resveratrol induced mitochondrial activity in a bell-shaped, dose-effect-dependent manner. Specifically, resveratrol treatment (3 µM, 48 hours) increased ATP production and cell viability and promoted the induction of cellular differentiation. These biological changes were associated with mitochondrial biogenesis. Electrophysiological recordings showed that resveratrol reduced the functional expression of an ultra rapid activating, slow inactivating, delayed rectifier potassium current (IKur) that is associated with a plasma membrane depolarization and that promotes an increase in intracellular Ca2+. CONCLUSION(S): The effects of resveratrol on potassium current and mitochondrial biogenesis in h-GCs could explain the beneficial effects of this polyphenol on the physiology of the female reproductive system. These findings suggest there are therapeutic implications of resveratrol in a clinical setting.

Legionella pneumophila serogroup 3 pneumonia in a patient with low-grade 4 non-Hodgkin lymphoma: a case report.

INTRODUCTION: Nosocomial legionellosis has generally been described in immunodepressed patients, but Legionella pneumophila serogroup 3 has rarely been identified as the causative agent. CASE PRESENTATION: We report the case of nosocomial L. pneumophila serogroup 3 pneumonia in a 70-year-old Caucasian man with non-Hodgkin lymphoma. Diagnosis was carried out by culture and real-time polymerase chain reaction of bronchoalveolar lavage fluid. The results of a urinary antigen test were negative. A hospital environmental investigation revealed that the hospital water system was highly colonized by L. pneumophila serogroups 3, 4, and 8. The hospital team involved in the prevention of infections was informed, long-term control measures to reduce the environmental bacterial load were adopted, and clinical monitoring of legionellosis occurrence in high-risk patients was performed. No further cases of Legionella pneumonia have been observed so far. CONCLUSIONS: In this report, we describe a case of legionellosis caused by L. pneumophila serogroup 3, which is not usually a causative agent of nosocomial infection. Our research confirms the importance of carrying out cultures of respiratory secretions to diagnose legionellosis and highlights the limited value of the urinary antigen test for hospital infections, especially in immunocompromised patients. It also indicates that, to reduce the bacterial load and prevent nosocomial legionellosis, appropriate control measures should be implemented with systematic monitoring of hospital water systems.

Immune response to Candida albicans is preserved despite defect in O-mannosylation of secretory proteins.

The PMT gene family in Candida albicans encodes five isoforms of the protein mannosyltransferases that initiate O-mannosylation of secretory proteins. Mutations at the Pmt level have been associated with differences in pathogenicity, e.g. in contrast to pmt5/pmt5, pmt2/PMT2 mutants showed poor virulence. Our objective was to determine whether these differences were related to the capacity of pmt2/PMT2 and pmt5/pmt5 to (i) express differences in selected virulence factors, and (ii) stimulate the natural immune system. The results show that pmt mutants (i) form hyphae in serum, (ii) show defective production of proteases but not of phospholipases with respect to the parental strain, (iii) undergo mycelial transition in the kidneys of hematogenously infected animals, (iv) are phagocytosed and killed by macrophages similar to the parental strain, although neutrophils are unable to destroy pmt5/pmt5, (v) engage TLR4 and stimulate MyD88 leading to NF-kappaB activation, and (vi) stimulate cytokine production by macrophages. Collectively our findings suggest that the defect in protein O-mannosylation in C. albicans cause attenuation of the virulence although the antigenic factors that retain the capacity to stimulate an efficient immune response are preserved.

Candida albicans mannoprotein influences the biological function of dendritic cells.

Cell wall components of fungi involved in induction of host immune response are predominantly proteins and glycoproteins, the latter being mainly mannoproteins (MP). In this study we analyse the interaction of the MP from Candida albicans (MP65) with dendritic cells (DC) and demonstrate that MP65 stimulates DC and induces the release of TNF-alpha, IL-6 and the activation of IL-12 gene, with maximal value 6 h post treatment. MP65 induces DC maturation by increasing costimulatory molecules and decreasing CD14 and FcgammaR molecule expression. The latter effect is partly mediated by toll-like receptor 2 (TLR2) and TLR4, and the MyD88-dependent pathway is involved in the process. MP65 enables DC to activate T cell response, its protein core is essential for induction of T cell activation, while its glycosylated portion primarily promotes cytokine production. The mechanisms involved in induction of protective response against C. albicans could be mediated by the MP65 antigen, suggesting that MP65 may be a suitable candidate vaccine.

Virulence of the fungal pathogen Candida albicans requires the five isoforms of protein mannosyltransferases.

The PMT gene family in Candida albicans encodes five isoforms of protein mannosyltransferases (Pmt proteins Pmt1p, Pmt2p, Pmt4p, Pmt5p, and Pmt6p) that initiate O mannosylation of secretory proteins. We compared virulence characteristics of pmt mutants in two complex, three-dimensional models of localized candidiasis, using reconstituted human epithelium (RHE) and engineered human oral mucosa (EHOM); in addition, mutants were tested in a mouse model of hematogenously disseminated candidiasis (HDC). All pmt mutants showed attenuated virulence in the HDC model and at least one model of localized candidiasis. The pmt5 mutant, which lacks in vitro growth phenotypes, was less virulent in the EHOM and HDC assays but had no consistent phenotype in the RHE assay. In contrast, the pmt4 and pmt6 mutants were less virulent in the RHE and HDC assays but not in the EHOM assay. The results stress the contribution of all Pmt isoforms to the virulence of C. albicans and suggest that the importance of individual Pmt isoforms may differ in specific host niches. We propose that Pmt proteins may be suitable targets for future novel classes of antifungal agents.

Mannoproteins from Cryptococcus neoformans promote dendritic cell maturation and activation.

Our previous data show that mannoproteins (MPs) from Cryptococcus neoformans are able to induce protective responses against both C. neoformans and Candida albicans. Here we provide evidence that MPs foster maturation and activation of human dendritic cells (DCs). Maturation was evaluated by the ability of MPs to facilitate expression of costimulatory molecules such as CD40, CD86, CD83, and major histocompatibility complex classes I and II and to inhibit receptors such as CD14, CD16, and CD32. Activation of DCs was measured by the capacity of MPs to promote interleukin-12 and tumor necrosis factor alpha secretion. DC-induced maturation and interleukin-12 induction are largely mediated by engagement of mannose receptors and presume MP internalization and degradation. DC activation leads to IkappaBalpha phosphorylation, which is necessary for nuclear factor kappaB transmigration into the nucleus. MP-loaded DCs are efficient stimulators of T cells and show a remarkable capacity to promote CD4 and CD8 proliferation. In conclusion, we have evidenced a novel regulatory role of MPs that promotes their candidacy as a vaccine against fungi.