Crude peptones from cowtail ray (Trygon sephen) viscera as microbial growth media

In the processing of cowtail ray (Trygon sephen) in Indonesia, viscera (up to 20% body weight) is wasted together with the head, frame and skin. A series of studies have been carried out to investigate the utilization of the viscera, and the present paper reports the conversion of the viscera into microbiological peptones. Ensilation using 3% (v/w) mixture of propionic and formic acids (1:1, v/v), followed by vacuum evaporation, has been used to prepare crude liquid peptones from cowtail ray viscera. These peptones were compared to three commercial peptones in supporting the growth of microorganisms. Mixed populations of microorganisms from foods (beef, egg and milk) and selected pure microorganisms (Aspergillus flavus, Bacillus subtilis, Saccharomyces cerevisiae, Escherichia coli and Staphylococcus aureus) were grown on liquid media containing 0.5 g test peptones/100 ml and the optical densities were monitored. The biomass produced was measured at the end of incubation period. The results show that crude peptones from cowtail ray viscera performed similar to or even better than commercial peptones as nitrogen sources for microorganisms growth. This revised version was published online in July 2006 with corrections to the Cover Date.     

Genotype and subtype analyses of hepatitis B virus (HBV) and possible co-infection of HBV and hepatitis C virus (HCV) or hepatitis D virus (HDV) in blood donors, patients with chronic liver disease and patients on hemodialysis in Surabaya, Indonesia

Four subtypes (adw, adr, ayw, and ayr ) and eight genotypes (A to H) of the hepatitis B virus (HBV) have been identified. They appear to be associated with particular geographic distribution, ethnicity, and possibly clinical outcomes. In this study, hepatitis B surface antigen (HBsAg) subtyping and HBV genotyping were carried out on sera obtained from HBsAg-positive HBV carriers, including healthy blood donors; patients with acute hepatitis, chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma; and patients on hemodialysis all located in Surabaya, Indonesia. We report here that all HBV isolates tested in Surabaya belonged to genotype B, with more than 90% of them being classified into subtype adw. Our results also revealed that prevalence of hepatitis C virus (HCV) co-infection among HBV carriers in Surabaya was approximately 10% for healthy blood donors and patients with chronic liver disease, and approximately 60% for patients on maintenance hemodialysis. Interestingly, HBsAg titers were lower in HBV carriers with HCV co-infection than in those without HCV co-infection. We also found that prevalence of hepatitis D virus (HDV) co-infection was < 0.5% among HBV carriers in Surabaya.