Résumé
Objective To explore inhibitory effects of genome-specific, chemically synthesized siRNAs (small interference RNA) against NS3 gene of hepatitis C virus (HCV) 1a genotype in stable Huh-7 (human hepatoma) cells as well as against viral replication in serum-inoculated Huh-7 cells. Methods Stable Huh-7 cells persistently expressing NS3 gene were produced under antibiotic gentamycin (G418) selection. The cell clones resistant to 1 000 μg antibiotic concentration (G418) were picked as stable cell clones. The NS3 gene expression in stable cell clone was confirmed by RT-PCR and Western blotting. siRNA cell cytotoxicity was determined by MTT cell proliferation assay. Stable cell lines were transfected with sequence specific siRNAs and their inhibitory effects were determined by RT-PCR, real-time PCR and Western blotting. The viral replication inhibition by siRNAs in serum inoculated Huh-7 cells was determined by real-time PCR. Results RT-PCR and Western blot analysis confirmed NS3 gene and protein expression in stable cell lines on day 10, 20 and 30 post transfection. MTT cell proliferation assay revealed that at most concentrated dose tested (50 nmol/L), siRNA had no cytotoxic effects on Huh-7 cells and cell proliferation remained unaffected. As demonstrated by the siRNA time-dependent inhibitory analysis, siRNA NS3-is44 showed maximum inhibition of NS3 gene in stable Huh-7 cell clones at 24 (80%, P = 0.013) and 48 h (75%, P = 0.002) post transfection. The impact of siRNAs on virus replication in serum inoculated Huh-7 cells also demonstrated significant decrease in viral copy number, where siRNA NS3-is44 exhibited 70% (P < 0.05) viral RNA reduction as compared to NS3-is33, which showed a 64% (P < 0.05) decrease in viral copy number. siRNA synergism (NS3-is33 + NS3-is44) decreased viral load by 84% (P < 0.05) as compared to individual inhibition by each siRNA (i.e., 64%–70% (P < 0.05)) in serum-inoculated cells. Synthetic siRNAs mixture (NS5B-is88 + NS3-is33) targeting different region of HCV genome (NS5B and NS3) also decreased HCV viral load by 85% (P < 0.05) as compared to siRNA inhibitory effects alone (70% and 64% respectively, P < 0.05). Conclusions siRNAs directed against NS3 gene significantly decreased mRNA and protein expression in stable cell clones. Viral replication was also vividly decreased in serum infected Huh-7 cells. Stable Huh-7 cells expressing NS3 gene is helpful to develop anti-hepatitis C drug screening assays. siRNA therapeutic potential along with other anti-HCV agents can be considered against hepatitis C.
Résumé
OBJECTIVE@#To explore inhibitory effects of genome-specific, chemically synthesized siRNAs (small interference RNA) against NS3 gene of hepatitis C virus (HCV) 1a genotype in stable Huh-7 (human hepatoma) cells as well as against viral replication in serum-inoculated Huh-7 cells.@*METHODS@#Stable Huh-7 cells persistently expressing NS3 gene were produced under antibiotic gentamycin (G418) selection. The cell clones resistant to 1000 μg antibiotic concentration (G418) were picked as stable cell clones. The NS3 gene expression in stable cell clone was confirmed by RT-PCR and Western blotting. siRNA cell cytotoxicity was determined by MTT cell proliferation assay. Stable cell lines were transfected with sequence specific siRNAs and their inhibitory effects were determined by RT-PCR, real-time PCR and Western blotting. The viral replication inhibition by siRNAs in serum inoculated Huh-7 cells was determined by real-time PCR.@*RESULTS@#RT-PCR and Western blot analysis confirmed NS3 gene and protein expression in stable cell lines on day 10, 20 and 30 post transfection. MTT cell proliferation assay revealed that at most concentrated dose tested (50 nmol/L), siRNA had no cytotoxic effects on Huh-7 cells and cell proliferation remained unaffected. As demonstrated by the siRNA time-dependent inhibitory analysis, siRNA NS3-is44 showed maximum inhibition of NS3 gene in stable Huh-7 cell clones at 24 (80%, P = 0.013) and 48 h (75%, P = 0.002) post transfection. The impact of siRNAs on virus replication in serum inoculated Huh-7 cells also demonstrated significant decrease in viral copy number, where siRNA NS3-is44 exhibited 70% (P < 0.05) viral RNA reduction as compared to NS3-is33, which showed a 64% (P < 0.05) decrease in viral copy number. siRNA synergism (NS3-is33 + NS3-is44) decreased viral load by 84% (P < 0.05) as compared to individual inhibition by each siRNA (i.e., 64%-70% (P < 0.05)) in serum-inoculated cells. Synthetic siRNAs mixture (NS5B-is88 + NS3-is33) targeting different region of HCV genome (NS5B and NS3) also decreased HCV viral load by 85% (P < 0.05) as compared to siRNA inhibitory effects alone (70% and 64% respectively, P < 0.05).@*CONCLUSIONS@#siRNAs directed against NS3 gene significantly decreased mRNA and protein expression in stable cell clones. Viral replication was also vividly decreased in serum infected Huh-7 cells. Stable Huh-7 cells expressing NS3 gene is helpful to develop anti-hepatitis C drug screening assays. siRNA therapeutic potential along with other anti-HCV agents can be considered against hepatitis C.
Résumé
Infection with Campylobacter jejuni is one of the most common causes of gastroenteritis worldwide; it occurs more frequently than do infections caused by Salmonella species, Shigella species, or Escherichia coli O157:H7. In developed countries, the incidence of Campylobacter jejuni infections peaks during infancy and again during early adulthood. Most infections are acquired by the consumption and handling of poultry. Only 3 [1.7%] of stool samples were positive for C. jejuni. Of the chickens 98/120 [81.7%] were contaminated with C. jejuni
This study revealed a high prevalence of Campylobacter. An alarming recent trend is the rapid emergence of antimicrobial agent-resistant Campylobacter strains all over the world. Food-borne diseases represent a major public health problem worldwide. Careful food preparation and cooking practices may prevent some Campylobacter infections
Résumé
Since the discovery of Helicobacter pylori, much progress have been made worldwide in different aspects of the organism. In spite of these advances, many aspects still remain unclear. The present study was carried out to assess the seroprevalence of H. pylori infection among healthy blood donors. A total of 435 blood samples from healthy blood donors from different regions of Makkah Al-Mukkarramah were collected. A questionnaire was completed to obtain epidemiological information such as age, sex, smoking, residence, nationality. Any complains of gastric symptoms from the subjects were obtained from medical records. The age range was between 18 to 52 years, with a mean age of 35 years. Samples were taken to determine IgG antibodies against H. pylori using a commercial ELISA test. Overall results showed 309 individuals [71%] IgG positive for H. pylori antibodies, 126 individuals [29%] IgG negative for H. pylon antibodies comparing this result with result of other studies which revealed [63%] IgG positive for H. pylori antibodies incidence in Makkah. Furthermore the seroprevalence results showed strong positive association with nationality and Makkah regions. However, low socio-economic status negatively affecting the seropositivity. We concluded that commercial IgG serology is one of more modern diagnostic tool for the assessment of present or previous H. pylori infections as well as silent infections since one third of the randomly chosen population of blood donors were found to be seropositive