Acta Microbiologica Bulgarica

43-44

Authors: Mayer, F.

In recent years more people die each year from cardiovascular diseases (CVDs) than from any other cause and 17.7 million people died from CVDs in 2015, representing about one third of all global deaths ac¬cording to the WHO. Streptokinase is a thrombolytic agent with systemic fibrinolytic effect. It is a non-en¬zymatic protein produced by β haemolytic streptococci and activates the fibrinolytic system indirectly. Streptokinase is used widely and routinely for treatment of acute myocardial infarctions. In this study strep¬tokinase gene from Streptococcus pyogenes C1 was cloned in pET28a vector and transferred to Escherichia coli BL21. Expressed protein was purified by Ni-NTA column and visualized with SDS-PAGE. Streptoki¬nase (SK) coding DNA fragment was amplified from S. pyogenes C1 genomic DNA by PCR. The amplifi¬cation products were inserted into the cloning and expression vector pET28a(+). Recombinant pET28a(+) plasmid with recSK gene were then introduced to E. coli BL21 (DE3) by electroporation. The streptokinase encoded by the plasmid pET28a(+) contains the mature streptokinase with the 6X histidine-tag.

53-58

Authors: Adeogun, O. S., David, O. M., Adesina, A. O., Babalola, T. O.

Hepatitis B virus (HBV) and Hepatitis C virus (HCV) infections cause chronic hepatitis in humans. The co-infections of these viruses with human immunodeficiency virus (HIV) have increased the burden, especially in the resource-poor nations of the world. In this study we determine the burden of HBV and/ or HCV with HIV among pregnant women attending selected General Hospitals in Ondo State, Nigeria. The sera of consented subjects were collected and screened for the presence of HBV using enzyme-linked Immunosorbent Assay (ELISA) kits while HIV was detected using WHO approved rapid kit and its confir-mation was done with Western blot assay. Out of two thousand, nine hundred ninety-eight (2.998) pregnant women screened, the numbers positive for HBV (HBsAg), HCV (antibody) and HIV (antibody) were 60, 54 and 28, respectively. The highest HIV seroprevalence was detected among women in the age group of 35- 39 years. The seroprevalence of co-infections HBV and HCV was 0.07 % while those of HIV and HBV, and HIV and HCV were 0.03 % each. None of the subjects had the three viruses. The difference in demographic characteristics of the study population in the study areas might explain the varying results observed in this study. Pregnant women should not only be screened for HIV but also for both Hepatitis B and C infections during their first ante-natal visit.

63-67

Authors: Shilev, S.

Arsenic is a common contaminant in soils, affecting soil microbiome and all soil organisms. The present study examined arsenate tolerance of two Saccharomyces cerevisiae strains isolated from contami¬nated soil. Their tolerance to sodium arsenate (AsV) was studied in a liquid medium for 24 hours, while the ability of the populations to reduce their intracellular arsenic content was subsequently investigated through kinetic studies of arsenate transport at 33.3, 133.2, and 266.4 μM of AsV. The dependence of tolerance on the efflux system was demonstrated by the use of amiloride hydrochloride, which is known as a suppressor of ion transport through the cell membrane. The maximum concentration tolerated by S. cerevisiae AS09 was found to be about 72.8% lower than that by the tolerant S. cerevisiae AS07. The influx and efflux of arsenate across the cell membranes of both strains were dependent on the concentration of metalloid in the medium and on the anion net balance. Both strains rapidly increased their internal As concentration to a maximum point, although only the tolerant strain was able to decrease it subsequently in all concentrations used. When the highest concentration was applied, the cells of the non-tolerant strain were found to be dead. When amiloride hydrochloride was used it was found that the tolerant cells behaved like sensitive cells, and at 266.4 μM the cells of both strains were found to be dead, because the extrusion of the toxic anion was interrupted. Kinetic differences in arsenate transport through the cell membrane explain the different degrees of tolerance of the studied strains.