Biomedical subjects

Vittorio Saba

Publications and source records attributed to Vittorio Saba.

43 records · Page 3Linked to original sources

PubMed2003

RNA III inhibiting peptide inhibits in vivo biofilm formation by drug-resistant Staphylococcus aureus.

Staphylococcus aureus is a prevalent cause of bacterial infections associated with indwelling medical devices. RNA III inhibiting peptide (RIP) is known to inhibit S. aureus pathogenesis by disrupting quorum-sensing mechanisms. RIP was tested in the present study for its ability to inhibit S. aureus biofilm formation in a rat Dacron graft model. The activity of RIP was synergistic with those of antibiotics for the complete prevention of drug-resistant S. aureus infections.

Animals↗

PubMed2002

Cationic peptides combined with betalactams reduce mortality from peritonitis in experimental rat model.

The efficacy of cationic peptides combined with betalactams was investigated in a peritonitis rat model. Intraabdominal sepsis was induced in adult Wistar rats via cecal ligation and single puncture. The study included eight drug-treated groups: each of them received intravenous polymyxin-E (1 mg/kg), buforin II (1 mg/kg), imipenem (20 mg/kg), amoxicillin-clavulanate (50 mg/kg), polymyxin-E (1 mg/kg) plus imipenem (20 mg/kg), or amoxicillin-clavulanate (50 mg/kg), and buforin II (1 mg/kg) plus imipenem (20 mg/kg), or amoxicillin-clavulanate (50 mg/kg). The study included an untreated control group that received intravenous isotonic sodium chloride solution. All compounds significantly reduced the lethality and the number of bacteria in abdominal fluid compared with saline treatment. Among compounds, imipenem showed the highest antimicrobial activity, while buforin II produced the highest reduction in plasma endotoxin and TNF-alpha levels. Overall, buforin II and imipenem association were the most effective therapeutic approach. Data presented here suggest the potential advantages of combining antimicrobial agents and compounds able to neutralize the biological effect of the endotoxin.

Amoxicillin-Potassium Clavulanate Combination↗

PubMed2002

Temporin A as a prophylactic agent against methicillin sodium-susceptible and methicillin sodium-resistant Staphylococcus epidermidis vascular graft infection.

OBJECTIVE: The purpose of this study was to investigate the efficacy of temporin A as a prophylactic agent in a rat model of vascular graft infection from methicillin sodium-susceptible and methicillin sodium-resistant Staphylococcus epidermidis. METHODS: The prospective, randomized, controlled animal study set in a research laboratory in a university hospital used 280 adult male Wistar rats (weight range, 280 to 350 g). Graft infections were established in the back subcutaneous tissue of rats with implantation of 1-cm(2) sterile Dacron grafts followed by topical inoculation with 2 x 10(7) colony-forming units of S epidermidis. The study for each staphylococcal strain included: one control group (no graft contamination), one contaminated group that did not receive any antibiotic prophylaxis, one contaminated group that received temporin A-soaked graft, two contaminated groups that received perioperative intraperitoneal cefazolin (30 mg/kg) or vancomycin hydrochloride prophylaxis (10 mg/kg), and two contaminated groups that received temporin A-soaked graft and perioperative intraperitoneal cefazolin (30 mg/kg) or vancomycin hydrochloride (10 mg/kg) prophylaxis. All grafts were explanted at 7 days after implantation. The main outcome measure was quantification of bacterial contamination. RESULTS: Overall, the perioperative prophylaxis based on soaked grafts was not significantly different to that of parenteral vancomycin hydrochloride. Only the combination between temporin A and vancomycin hydrochloride produced a complete bacterial inhibition for both strains. CONCLUSION: Temporin A showed a similar antibacterial in vitro activity against the two different strains. The in vivo results suggest its potential use in providing prophylaxis to direct graft contamination when used in combination with parenteral vancomycin hydrochloride.

Animals↗

PubMed2002

Therapeutic efficacy of intraperitoneal polymyxin B and polymyxin-like peptides alone or combined with levofloxacin in rat models of septic shock.

The efficacy of two polymyxin-like peptides, KFFKFFKFF and IKFLKFLKFL, alone and combined with levofloxacin, was investigated in a rat model of septic shock. Rats were given an ip injection of 2 x 10(10) cfu of Escherichia coli and randomized to receive ip isotonic sodium chloride solution, 7 mg/kg levofloxacin, 1 mg/kg polymyxin B and 1 mg/kg of each polymyxin-like peptides alone or combined with 7 mg/kg levofloxacin. Polymyxins achieved a significant reduction in plasma endotoxin and tumour necrosis factor alpha (TNF-alpha) concentration. Levofloxacin significantly reduced the bacterial growth and TNF-alpha concentration. The combinations of polymyxin-like peptides and levofloxacin demonstrated the highest efficacy.

Animals↗

PubMed2002

Single-dose intraperitoneal magainins improve survival in a gram-negative-pathogen septic shock rat model.

The therapeutic efficacies of three polycationic peptides selected among the class of the magainins (magainin I, magainin II, and magainin II amide), alone and combined with piperacillin, were investigated in a rat model of septic shock. Rats were given an intraperitoneal injection of 2 x 10(10) CFU of Escherichia coli and randomized to receive intraperitoneally isotonic sodium chloride solution, 60 mg of piperacillin per kg of body weight, and 1 mg of each magainin per kg alone and combined with 60 mg of piperacillin per kg. The main outcome measures were bacterial growth in abdominal exudate and plasma, endotoxin and tumor necrosis factor alpha (TNF-alpha) concentrations in plasma, and lethality. Treatments with the magainins achieved significant reductions of bacterial growth and plasma endotoxin and TNF-alpha concentrations. In general, treatments with the combinations of magainins and piperacillin demonstrated the highest efficacies.

Animals↗

PubMed2002

Potential therapeutic role of cationic peptides in three experimental models of septic shock.

The therapeutic efficacies of buforin II, indolicidin, and KFFKFFKFF were investigated in three rat models of septic shock: (i) rats injected intraperitoneally with 10 microg of Escherichia coli O111:B4 lipopolysaccharide, (ii) rats given an intraperitoneal injection of 2 x 10(10) CFU of Escherichia coli ATCC 25922, and (iii) rats in which intra-abdominal sepsis was induced via cecal ligation and single puncture. All animals were randomized to receive parenterally isotonic sodium chloride solution, 1 mg of buforin II per kg of body weight, 1 mg of indolicidin per kg, 1 mg of KFFKFFKFF per kg, and 20 mg of imipenem per kg. The main outcome measures were bacterial growth in abdominal exudate and plasma, endotoxin and tumor necrosis factor alpha (TNF-alpha) concentrations in plasma, and lethality. Treatment with all peptides resulted in significant reductions in plasma endotoxin and TNF-alpha concentrations compared with those resulting from the imipenem and saline treatments. On the other hand, imipenem treatment significantly reduced the levels of bacterial growth compared with the reductions achieved with the peptide and saline treatments. All compounds reduced the rates of death compared to that for the controls. Although the peptides demonstrated lower levels of antimicrobial activity than imipenem, they exhibited the dual properties of antimicrobial and antiendotoxin agents.

Animals↗

PubMed2002

Efficacy of quinupristin-dalfopristin in preventing vascular graft infection due to Staphylococcus epidermidis with intermediate resistance to glycopeptides.

A rat model was used to investigate the efficacy of quinupristin-dalfopristin (Q-D) in the prevention of vascular prosthetic graft infection due to methicillin-resistant Staphylococcus epidermidis with intermediate resistance to glycopeptides. The in vitro activity of the compound was compared to that of vancomycin by MIC determination and time-kill study. Moreover, the efficacy of collagen-sealed Q-D-soaked Dacron was evaluated in a rat model of graft infection. Graft infections were established in the subcutaneous tissue of the backs of 120 adult male Wistar rats. The in vivo study included a control group, one contaminated group that did not receive any antibiotic prophylaxis, two contaminated groups that received grafts soaked with 10 and 100 micro g of Q-D per ml, respectively, and two contaminated groups that received grafts soaked with 10 and 100 micro g of vancomycin per ml, respectively. Rats that received Dacron grafts soaked with 100 micro g of Q-D per ml showed no evidence of infection (<10 CFU/ml). In contrast, for rats that received Dacron grafts soaked with 10 micro g of Q-D per ml and Dacron grafts soaked with 10 or 100 micro g of vancomycin per ml, the quantitative graft cultures demonstrated 2.2 x 10(2) +/- 1.3 x 10(2), 2.2 x 10(6) +/- 1.9 x 10(5), and 5.6 x 10(2) +/- 0.3 x 10(2) CFU/ml, respectively. Taken together the results of the study demonstrate that the use of Dacron grafts soaked with Q-D can result in significant bacterial growth inhibition and show that this compound is potentially valuable for prevention of vascular prosthetic graft infection.

Animals↗