Antimicrobial Activity of Euplotin C, the Sesquiterpene Taxonomic Marker from the Marine Ciliate Euplotes crassus

Strains of the marine ciliate protist Euplotes crassus produce exclusive terpenoids called euplotins that play an ecological role. Among these derivatives, euplotin C is the main of four secondary metabolites isolated from cultures of this protozoon and represents the sesquiterpene taxonomic marker from E. crassus. Because different terpenoid metabolites of plant origin showed a certain antimicrobial activity, we assessed the compound euplotin C, purified by high-pressure liquid chromatography and solubilized in two solubility enhancers, against the protozoa Leishmania major and Leishmani infantum, the fungus Candida albicans, and nine strains of gram-positive and gram-negative microorganisms. An activity of euplotin C against Leishmania promastigotes was demonstrated (50% lethal doses were 4.6 or 8.1 μg/ml depending on the agent used to solubilize the compound), while the effect was less evident on Candida and nearly absent on bacteria. A nonsignificant cytotoxicity (50% lethal dose, >200 μg/ml) against the J774 cell line was observed. A leishmanicidal activity was also shown by the living, euplotin-producing cells of E. crassus cultured together with promastigotes; this activity increased with time from 10 min to 6 h of incubation. This study provides an initial rationale for the evaluation of euplotin C and other similar natural products as alternative or possibly synergistic compounds for current antiprotozoon chemotherapeutics

Real-time ed end-point Polymerase Chain Reaction per la quantizzazione del DNA di Citomegalovirus: confronto tra metodi e con il test per l’antigene pp65

Quantitave Polymerase Chain Reaction (PCR) for Cytomegalovirus (CMV) DNA provides highly sensitive and specific data for detecting CMV as well as monitoring the infection and determining the appropriate antiviral strategy.To determine the clinical application of a recently introduced real-time (RT) PCR assay for CMV DNA quantitation in peripheral blood leukocytes (PBLs) and defining its correlation with the commercial quantitative end-point (EP) PCR method COBAS AMPLICOR CMV Monitor and pp65 antigen test. Sequential PBL samples (n=158) from 32 liver transplanted patients with CMV asymptomatic infection and positive for CMV DNA by EP-PCR were retrospectively analysed with RT-PCR and studied according to pp65 antigen levels. A good correlation was found between RT-PCR and pp65 antigen test (r=0.691) and between the two PCR assays (r=0.761). RT-PCR data were significantly higher in pre-emptive treated patients (those with >20 pp65+positive cells, median value: 3.8 log10 copies/500,000 PBLs) than in not-treated ones (2.9 logs).According to pp65 levels of 0, 1-10, 11-20, 21-50, 51-100 and >100 positive cells/200,000 PBLs, median CMV DNA load by RT-PCR was 2.6, 3.0, 3.6, 4.0. 4.2 and 4.8, log10 copies/ 500,000 PBLs, respectively (EP-PCR CMV DNA levels: 2. 8, 2.9, 3.8, 3.7, 3.9 and 4.0 logs). For samples with >20 pp65+cells, that is above the level at which pre-emptive therapy was started, RT-PCR values were significantly higher than in groups with less than 20 pp65+cells, whereas EP-PCR values did not significantly differ and showed a slower progression rate. Dilutions of DNA from CMV AD169 strain were used to probe RT-PCR reproducibility (between and intra-assay variability < 2%) and sensitivity (100% detection rate at 10 copies/reaction, 28.5% with EP-PCR). A significant improvement is coming from the introduction of RT-PCR to the study of CMV DNA dynamics in differently CMV infected patients due to a more reliable quantitation of CMV DNA for moderate and high DNA level compared to EP-PCR with better sensitivity and specificity. RTPCR gives more precise informations on viral load kinetics for evaluating the infection progress and assessing antiviral response, significantly simplifying and accelerating the process of producing a reliable quantification of CMV DNA for clinical purposes

COBAS AmpliPrep-COBAS TaqMan Hepatitis B Virus (HBV) Test: a Novel Automated Real-Time PCR Assay for Quantification of HBV DNA in Plasma

Success in antiviral therapy for chronic hepatitis B is supported by highly sensitive PCR-based assays for hepatitis B virus (HBV) DNA. Nucleic acid extraction from biologic specimens is technically demanding, and reliable PCR results depend on it. The performances of the fully automatic system COBAS AmpliPrep-COBAS TaqMan 48 (CAP-CTM; Roche, Branchburg, NJ) for HBV DNA extraction and real-time PCR quantification were assessed and compared to the endpoint PCR COBAS AMPLICOR HBV monitor (CAHBM; Roche). Analytical evaluation with a proficiency panel showed that CAP-CTM quantitated HBV DNA levels in one single run over a wide dynamic range (7 logs) with a close correlation between expected and observed values (r = 0.976, interassay variability below 5%). Clinical evaluation, as tested with samples from 92 HBsAg-positive patients, demonstrated excellent correlation with CAHBM (r = 0.966, mean difference in quantitation = 0.36 log(10) IU/ml). CAP-CTM detected 10% more viremic patients and longer periods of residual viremia in those on therapy. In lamivudine (LAM)-resistant patients, the reduction of HBV DNA after 12 months of Adefovir (ADF) was higher in the combination (LAM+ADF) schedule than in ADF monotherapy (5.1 logs versus 3.5 logs), suggesting a benefit in continuing LAM. CAP-CTM detected HBV DNA in liver biopsy samples from 15% of HBsAg-negative, anti-HBcAg-positive graft donors with no HBV DNA in plasma. The amount of intrahepatic HBV DNA was significantly lower in occult HBV infection than in overt disease. CAP-CTM can improve the management of HBV infection and the assessment of antiviral therapy and drug resistance, supporting further insights in the emerging area of occult HBV infection

HIV-1 detection in the olfactory mucosa of HIV-1 infected participants

OBJECTIVE: Human Immunodeficiency virus (HIV) infection chronically affects the central nervous system (CNS). Olfactory mucosa (OM) is a unique site in the respiratory tract that is directly connected to the CNS, thus we wanted to evaluate OM as a surrogate of CNS sampling. DESIGN: We conducted a preliminary study examining HIV populations and susceptible cells in the OM. METHODS: OM was sampled by minimally invasive brushing. CSF analyses were performed as per routine clinical procedures. OMP, CD4, CD8 and TAT expressions were assessed by immunohistochemistry. Plasma, CSF and OM HIV-RNA were quantified using the CAP/CTM assay, while HIV proviral DNA was evaluated on PBMC and OM. HIV-1 env deep sequencing was performed for phylogenetic analysis. RESULTS: 88.2% of ART naive participants (15/17) and 21.4% of ART treated participants (6/28) had detectable HIV-RNA in samples from their OM; CSF escape was more common in patients with OM escape (50% vs. 7.9%, p\u200a=\u200a0.010). OM samples contained few cells positive for CD4, CD8 or HIV-DNA and no HIV TAT-positive cells, indicating that this approach efficiently samples virions in the OM, but not HIV-infected cells. Yet, using a deep sequencing approach to phylogenetically compare partial HIV env genes in five untreated participants, we identified distinct viral lineages in the OM. CONCLUSIONS: The results of this study suggest that nasal brushing is a safe and useful technique for sampling the olfactory mucosa. HIV RNA was detected in most na\uefve and in some treated patients warranting larger longitudinal studies