3 research outputs found
ANALISIS BAKTERI Escherichia coli PADA MAKANAN SIAP SAJI DI KANTIN RUMAH SAKIT X DAN KANTIN RUMAH SAKIT Y: Analysis of Escherichia coli Bacteria on Fast Food at hospital X and Y cafetaria
No full textThe increasing human activity makes the preference for fast food increases. However, some people do not pay attention to the hygiene conditions of food processed from food stalls. Food handlers, equipment utilization, food processing, clean water, and the packaging are the critical points of bacterial contamination. Escherichia coli is a bacterium that usually used as the indicator of food hygiene. The objective of this study is to examine the contamination of coliform bacteria, especially E. coli at two hospital cafeteria by using MPN method and questionnaire regarding the implementation of the basic principles of hygiene. Stages of tests performed that are the presumption test, confirmation test, complementary test, gram stain test, biochemical test IMViC and supported by a questionnaire. From the two locations tested, some samples showed positive result in a presumption test and confirmation test but negatively complementary to biochemical test. This indicates that the sample does not contain E. coli bacteria in food, but there is the possibility of Citrobacter. The negative results of the IMVIC test showed that it is possible bacteria found in the presumption test and confirmation test not E. coli and non-pathogenic bacteria. Based on the results of the questionnaire, most of restaurant owner has understood to served food. Food at the hospital X and Y cafetaria are safe to consume because it has a negative E.coli
Immunogenic Subviral Particles Displaying Domain III of Dengue 2 Envelope Protein Vectored by Measles Virus
No full textabstract: Vaccines against the arthropod-borne dengue virus (DENV) are still commercially nonexistent. A subunit immunization strategy may be of value, especially if a safe viral vector acts as a biologically active adjuvant. The DENV envelope protein (E), the main target for neutralizing immune responses, has three conformational domains. The immunoglobulin-like and independently folding domain III (DIII) contains epitopes that elicit highly specific neutralizing antibodies. The hepatitis B small surface antigen (HBsAg, S) was used as a scaffold to display DENV 2 DIII on a virus-like particle (VLP). A measles virus (MV) was engineered to vector HBsAg and the hybrid glycoprotein DIII-HBsAg in two different loci (DIII-S). Despite the relatively deleterious effect on replication caused by the insertion of two transcription cassettes, the recombinant virus MVvac2(DIII-S,S)P induced the secretion of DIII-S hybrid VLP with a similar sucrose density as HBsAg particles (1.10-1.12g/ml) and peaked at 48 h post-infection producing 1.3x106 TCID50/ml infectious MV units in vitro. A second recombinant virus, MVvac2(DIII-S)N, was engineered to vector only the hybrid DIII-S. However, it did not induce the secretion of hybrid HBsAg particles in the supernatant of infected cells. The immunogenicity of the recombinant viruses was tested in a MV-susceptible small animal model, the experimental group which received two 105 TCID50 I.P. doses of MVvac2(DIII-S,S)P in a 28 day interval developed a robust immune response against MV (1:1280), HBsAg (787 mIU/ml) and DENV2 (Log10 neutralization index of 1.2) on average. In summary, it is possible to display DENV E DIII on hybrid HBsAg particles vectored by MV that elicit an immune response. This forms the basis for a potential vaccine platform against DENV.Dissertation/ThesisMasters Thesis Biology 201
Display of Domain III from Dengue 2 Envelope Protein on HBsAg Virus-like Particles Vectored by Measles Virus
No full textabstract: Dengue virus infects millions of people every year. Yet there is still no vaccine available to prevent it. Here we use a neutralizing epitope determinant on the dengue envelope (E) protein as an immunogen to be vectored by a measles virus (MV) vaccine. However the domain III (DIII) of the dengue 2 E protein is too small to be immunogenic by itself. In order for it to be displayed on a larger particle, it was inserted into the amino terminus of small hepatitis B surface antigen (HBsAg, S) coding sequence. To generate the recombinant MV vector and verify the efficiency of this concept, a reverse genetics system was used where the MV vectors express one or two additional transcription units to direct the assembly of hybrid HBsAg particles. Two types of recombinant measles virus were produced: pB(+)MVvac2(DIII-S,S)P and pB(+)MVvac2(DIII-S)N. Virus recovered from pB(+)MVvac2(DIII-S,S)P was viable. An ELISA assay was performed to demonstrate the expression and secretion of HBsAg. Supernatant from MVvac2(DIII-S,S)P infected cells confirmed that hybrid HBsAg-domain III particles with a density similar to traditional HBsAg particles were released. Characteristics of the subviral particle have been analyzed for the successful incorporation of domain III. The replication fitness of the recombinant MV was evaluated using multi-step growth kinetics and showed reduced replication fitness when compared to the parental strain MVvac2. This demonstrates that viral replication is hindered by the addition of the two inserts into MV genome. Further analysis of MVvac2(DIII-S)N is needed to justify immune response studies in a small animal model using both of the generated recombinant vectors
