Extraction and characterization of collagen from the skin of Amazonian freshwater fish pirarucu

The need to fully exploit fishing resources due to increasing production and consequent waste generation requires research to promote the sustainability of the fishing industry. Fish waste from the industry is responsible for relevant environmental contamination. However, these raw materials contain high amounts of collagen and other biomolecules, being attractive due to their industrial and biotechnological applicability. Thus, to reduce the waste from pirarucu (Arapaima gigas) processing, this study aimed to obtain collagen from pirarucu skin tissue. The extraction process used 0.05 M sodium hydroxide, 10% butyl alcohol, and 0.5 M acetic acid, with extraction temperature of 20°C. The obtained yield was 27.8%, and through sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), it was determined that the collagen obtained was type I. This study showed that collagen solubility was highest at pH 3 and the lowest solubility was at concentrations of 3% sodium chloride. The denaturation temperature of collagen was 38.1°C, and its intact molecular structure was observed using the Fourier transform infrared spectrophotometry technique with an absorption radius of 1. The results showed that it was possible to obtain collagen from pirarucu skin at 20°C, which has the typical characteristics of commercial type I collagen. In conclusion, the procedures used may be considered to be an interesting alternative for collagen extraction, a new product obtained from the processing of fish waste.

Evaluation of the Antimicrobial Activity of Sparfloxacin, Relative to Other Oral Antibiotics Against 1,125 Bacterial Isolates from 10 Medical Centers in Brazil.

A multicenter study was carried out in order to compare the in vitro activity of sparfloxacin to ciprofloxacin, amoxicillin/clavulanic acid, cephalexin, cefuroxine and azithromycin, against 1,125 microorganisms recently isolated from clinical specimens, most of them representative of respiratory tract infections. Sparfloxacin demonstrated potent action and was more active than the beta-lactam agents and azithromycin against most of the bacterial strains tested. Sparfloxacin was more potent (96% and 95% sensitivity, with MIC(90) of 0.19µg/mL and 0.5µg/mL, respectively)than the other antimicrobial agents tested against the Enterobacteriaceae family (Escherichia coli and Elebsiella pneumoniae). It was found to be equivalent in activity to ciprofloxacin (96% and 91% sensitivity and MIC(90) of 0.25 and 0.75µg/mL, respectively). Sparfloxacin was also found to be very active against the most fastidious microorganisms commonly associated to respiratory tract infections such as the penicillin-susceptible and resistant Streptococcus pneumoniae (MIC(90) 0.5µg/mL and 0.38µg/mL, respectively), ampicillin-susceptible and -resistant Haemophilus influenzae (MIC(90) 0.016µg/mL and 0.38µg/mL, respectively), beta-lactamase producing Moraxella catarrhalis (MIC(90) 0.032µg/mL) and non beta-lactamase producing M.catarrhalis (MIC(90) 0.5µg/mL).