Introduction: There are 5 identified DEC including EAEC, EHEC, EIEC, EPEC and ETEe. Virulent genes (for adherrnee, toxin, antibiotic resistance ...) play important roles in pathogenesis of DEe. Detection of DEC is very important in diagnosis, epidemiology survey and vaccine development. \r\n', u'Objectives: Detection of virulent gene distribution of DEC and non - DEe.\r\n', u'Object and methods: 161 strains of DEC (EAEC, EIEC, EPEC, TEC) and 100 strains of non - DEC were subjected to this study. PCR with specific primers were used to test these genes. \r\n', u'Results: EAEC that accounted for 50% of DEC, was identified and isolated. Aap gene was the highest prevalence in EAEC (96.5%), followed by aggR (79.1 %) and astA (60.5%). 37.2% of the strains harbor all three genes. None of strains had PCR results negative for these 3 genes. ETEC, EPEC and EIEC had aap, and astA gene at the prevalence from 7% to 72.7%. The highest prevalence of aap was seen in EIEC 72.7%), aggR in EIEC (45.5%), and astA in ETEC (50%). 14% of non - DEC had aggR and more than 30% of E. coli had aap and astA gene. \r\n', u'Conclusion: EAEC is prevalent at 50% among Diarreagenic E. coli. Aap is the most prevalent and the most commonly seen among EAEC isolates. The other three genes are at different prevalence. The findings contribute towards the vaccine development against diarrhea caused by E. coli. \r\n', u'
Distribution ; Virulent gene ; E.coli

Background: To distinguish the different types of pathogenic E. coli with other non-pathogenic E.coli in the intestine is extremely important in diagnosis. Up to date there are at least six types of E. coli that causes diarrhea. Objectives: We have designed a multiplex PCR assay for the direct detection of 6 categories of diarrheagenic Escherichia coli. Subjects and method: This techniques proved to be specific and rapid for detecting virulence genes from Shiga toxin-producing (stx and eae), enteropathoogenic (eae), enterotoxigenic (elt, est), ennteroinvasive (ipaH), enteroaggregative (aggR), and diffuse adherent (daaE) Esscherichia coli. The technique was applied to 295 clinical stool specimens. Results: The highest prevalence is EAggEC with 51 positive samples.(17.29%), 48 EIEC (16.27%), 17 EPEC (5.76%), 8 ETEC (LT) (2.71%), 5 ETEC (ST) (1.69%), 1 DAEC (0.34%), no STEC positive and 19 mix infections (6.44%). Conclusion: Multiplex PCR assay is a quick and highly accuurate technique. It is not only specific but can also amplify 7 virulence genes of diarrrheagenic E.coli at the same time. This method would offer an effective alternative to traditional culture methods for the identification and differentiation of human diarrhaegenic Escherichia coli.
direct PCR ; E.coli

Introduction: There are thousands of diabetes sufferers worldwide. In addition, there is an increased trend in Vietnam due to economic development, increased population, lifespan, and changing lifestyle. Insulin is a hormone, which is a natural protein. It plays an important role in the transformation of glucose in human and animal blood. Note, while insulin has not been produced in Vietnam, the production of recombinant Proinsulin is a premise for insulin. This study is based on a successful design of pET - 28a (+) Vector with recombinant Proinsulin codified gene.\r\n', u'Objectives: To define the human proinsulin codified gene and study the optimum conditions for the expression of proinsulin. \r\n', u'Subjects and method: To discover the appropriate conditions for the expression of proinsulin, including initial cell density, cultural temperature, IPTG concentration, and expression time. The product of the expression was confirmed by Sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SOS - PAGE) and reconfirmed by Western blotting with His - Tag antibody. \r\n', u'Results: Proinsulin expression was successfully proved by SOS - PAGE and Western blotting. Four appropriate conditions for the expression were confirmed as highlighted in the Conclusion. \r\n', u'Conclusion: The appropriate conditions for expression of proinsulin: cell density was 00600 0.6 - 1.0; the cultural temperature was 300C; IPTG concentration was 0.4 mM; the length of the culture time was 20 hours. \r\n', u'
Expression ; Proinsulin ; E.Coli ; Appropriate conditions