Rhamnolipid coating reduces microbial biofilm formation on titanium implants: an in vitro study

Background: Peri-implant mucositis and peri-implantitis are biofilm-related diseases causing major concern in oral implantology, requiring complex anti-infective procedures or implant removal. Microbial biosurfactants emerged as new anti-biofilm agents for coating implantable devices preserving biocompatibility. This study aimed to assess the efficacy of rhamnolipid biosurfactant R89 (R89BS) to reduce Staphylococcus aureus and Staphylococcus epidermidis biofilm formation on titanium. Methods: R89BS was physically adsorbed on titanium discs (TDs). Cytotoxicity of coated TDs was evaluated on normal lung fibroblasts (MRC5) using a lactate dehydrogenase assay. The ability of coated TDs to inhibit biofilm formation was evaluated by quantifying biofilm biomass and cell metabolic activity, at different time-points, with respect to uncoated controls. A qualitative analysis of sessile bacteria was also performed by scanning electron microscopy. Results: R89BS-coated discs showed no cytotoxic effects. TDs coated with 4 mg/mL R89BS inhibited the biofilm biomass of S. aureus by 99%, 47% and 7% and of S. epidermidis by 54%, 29%, and 10% at 24, 48 and 72 h respectively. A significant reduction of the biofilm metabolic activity was also documented. The same coating applied on three commercial implant surfaces resulted in a biomass inhibition higher than 90% for S. aureus, and up to 78% for S. epidermidis at 24 h. Conclusions: R89BS-coating was effective in reducing Staphylococcus biofilm formation at the titanium implant surface. The anti-biofilm action can be obtained on several different commercially available implant surfaces, independently of their surface morphology

Determinants of relapse after a short (12 weeks) course of antiviral therapy and re-treatment efficacy of a prolonged course in patients with chronic hepatitis C virus genotype 2 or 3 infection

In hepatitis C virus (HCV) genotypes 2 and 3 patients, the high rate of relapse after 12 to 16 weeks of antiviral therapy is the main concern for shortening treatment duration. This study was undertaken to delineate predictors of relapse after short treatment in patients with undetectable HCV RNA at treatment week 4 (RVR), and to report in RVR patients with relapse the sustained virological response (SVR) after a second 24-week course of therapy. RVR patients received pegylated interferon (Peg-IFN) alfa-2b (1.5 microg/kg) and ribavirin (1000-1200 mg/day) for 12 weeks; those who relapsed were re-treated with the same drug doses but for the extended standard duration of 24 weeks. Logistic regression analysis was applied to delineate predictors of relapse by using age, sex, route of transmission, body mass index (BMI), serum alanine aminotransferase (ALT), HCV genotypes, serum HCV RNA levels, and platelet counts as covariates. Of 718 patients with genotypes 2 and 3 who were started on therapy, 496 (69.1%) had undetectable HCV RNA at week 4. Of them, 409 patients (82.5%, CI 79.1-85.8) attained SVR, and 67 (14.1%, CI 10.4-16.5) relapsed. At regression analysis, only platelet count less than 140,000 mm(3) [odds ratio, 2.51; confidence interval (CI), 1.49-4.20] and BMI 30 or higher (odds ratio, 1.7; CI, 1.03-2.70) were independently associated with relapse. Forty-three of 67 patients with relapse agreed to be re-treated, and an SVR was achieved in 30 (70.0%) of them. Conclusion: We recommend 12 weeks course of therapy for patients with undetectable HCV RNA at treatment week 4, providing they present with no advanced fibrosis and low BMI

Individualized treatment with combination of Peg-interferon alpha 2b and ribavirin in patients with HCV genotype 3

Background & Aims: The benefit of individualizing treatment for patients with genotype 3 HCV infection on the basis of viral clearance at week 4 (wk4-R) has not been firmly established. Methods: Four hundred and fourteen patients received Peginterferon alpha-2b plus 1000–1200 mg of ribavirin daily according with body weight > or <75 kg. Patients were randomized to standard 24 weeks (Std24) or to a 12 or 36 weeks variable treatment duration (Var12/36). In the variable treatment arm, patients with or without wk4-R were allocated to either 12 or 36 weeks duration. Results: At treatment week 4, HCV RNA was undetectable in 262 patients (63.3%), 136 in the Std24, and 126 in the Var12/36 group (p = 0.41). In patients with wk4-R, end-of-treatment (EOT) responses were 80.4% (CI 85.4–95.3) and 97.6% (CI 94.9–99.9) in the two arms, respectively (p = 0.019). In patients without wk4-R, corresponding rates were 61.9% (50.6–73.2) and 75.3% (CI 65.9–84.6) (p = 0.08). SVR was attained in 302 patients, 71.4% (CI 65.3–77.6) in the St24 group and 74.3% (CI 58.4–80.3) in the variable 12/36 arm. Among patients with wk4-R, SVR was 81.6% (CI 75.1–88.1) and 82.5% (75.9–89.1), respectively. In patients without wk4-R, SVR amounted to 52.1% (CI 40.4–63.7) and 61.7 (CI 51.1–72.3) in the two arms (p = 0.25). Conclusions: HCV genotype 3 patients with week4-R may be treated safely with 12 weeks of therapy, provided that sufficiently high doses of ribavirin are administered. For patients still viremic at treatment week 4, SVR rates were numerically higher after 36 weeks of treatment than after the currently recommended 24 weeks

The aetiology of chronic hepatitis in Italy: results from a multicentre national study

Background: No recent national-level data on the aetiology of chronic hepatitis are available in Italy. Aim: To evaluate the current aetiology of chronic hepatitis in Italy. Patients: A total of 6210 chronic hepatitis patients (both prevalence and incident cases) consecutively admitted to 79 hospitals located throughout Italy were enrolled over a 6-month period in 2001. The hospitals were randomly selected through systematic cluster sampling. Results: The main agent associated with chronic hepatitis was hepatitis C virus, which was found in 76.5% of the patients (in 62.6% it was the only aetiologic factor). Hepatitis B surface antigen was present in the serum of 12.2% of the cases (in 9.2% it was the only aetiologic factor). Hepatitis B e antigen and hepatitis Delta were detected in 16.6% and 7.0%, respectively, of hepatitis B surface antigen-positive patients. A history of alcohol abuse was found in 19.2% of the cases (5.5% without viral infection). Autoimmune hepatitis and inborn metabolic disorders were extremely rare. The prevalence of hepatitis C virus-related cases was significantly lower in incident cases, compared to prevalent cases (55.1% versus 65.0%; p < 0.01). The mean alanine aminotransferase level was significantly higher in hepatitis B surface antigen-positive patients, compared to hepatitis B surface antigen-negative patients. The histology was less severe in non-viral-related cases. Conclusions: Hepatitis C virus is the most important pathogenic factor for chronic hepatitis in Italy; however, the comparison between prevalent and incident cases suggests that this infection will play a less important role in the future. A comparison with previous reports shows that both hepatitis B virus-related and hepatitis Delta virus-related cases are decreasing

Characteristics of HCV positive subjects referring to hospitals in Italy: a multicentre prevalence study on 6,999 cases

In 2001, 6 999 anti-HCV positive subjects referred to 79 Italian hospital in a 6 months enrolment period were evaluated. Of them, 5 632 (80.5%) tested anti-HCV positive alone, 1 163 (16.6%) reported also an excessive alcohol intake, and 204 (2.9%) were also HBsAg positive. Normal biochemistry was observed in 7.8% of cases, chronic hepatitis in 67.9% of cases, liver cirrhosis in 18.9% of cases, and hepatocellular carcinoma in 3.6% cases. HCV positive subjects with excessive alcohol intake were statistically significantly younger, of male sex, and having more severe liver disease than those without excessive alcohol intake. Adjusting for the confounding effect of age and sex by multiple logistic regression analysis, HCV positive chronic hepatitis cases drinking more than four alcoholic drinks daily were 2.2-fold (CI 95% = 1.3-4.0) more likely to progress to liver cirrhosis than teetotallers. These findings indicate that nearly a quarter of HCV positive subjects referred to hospitals in Italy have a severe liver disease causing a remarkable impact on the national health system. Excessive alcohol intake in HCV chronic hepatitis cases increases the risk of progression to liver cirrhosis. © 2005 Blackwell Publishing Ltd