Study of the cytoxin-associated gene A [CagA Gene] in helicobacter pylori using gastric biopsies of Iraqi patients

The Helicobacter pylori CagA gene is a major virulence factor that plays an important role in gastric pathologies. The size variation of CagA gene, which is dependent on the 3' repeat region, contains one or more Glu-Pro-Ile-Tyr-Ala [EPIYA] motifs and CagA multimerization [CM] motifs. Four segments flanking the EPIYA motifs, EPIYA A, B, C, or D, were reported to play a crucial role in the pathogenesis of H. pylori infection. The aim was to determine the roles of EPIYA segments and CM motifs in gastroduodenal pathogenesis in an Iraqi population. Gastric biopsies were collected from 210 patients with gastritis, duodenal ulcer [DU], gastric ulcer [GU], and gastric cancer [GC]. The EPIYA motif genotyping was determined by polymerase chain reaction and sequencing. The differences in age, gender, and CagA EPIYA motifs of H. pylori between GC, DU, GU and gastritis patients were analyzed using a 2-test. A total of 22 [45.8%] strains had three copies of EPIYA [ABC type], 2 [4.16%] had four copies [ABCC type], 6 [12.7%] had five copies [ABCCC type], 13 [27.08%] had two copies [AB type], 3 [6.25%] had the BC, and 2 [4.17%] had AC motif. The alignment of the deduced protein sequences confirmed that there were no East Asian type EPIYA-D sequences in Iraqi strains. A significant association was found between increase in number of EPIYA-C motifs and GU [P 0.01] compared with gastritis. The structure of the 3' region of the CagA gene in Iraqi strains was Western type with a variable number of EPIYA-C and CM motifs. A significant association was found between increase in number of EPIYA-C motifs and GU compared with gastritis indicating predictive association with the severity of the disease. The GenBank accession numbers for the partial CagA nucleotide sequences determined in this study are JX164093-JX164112

Effect of sub culturing and lyophilization on viability and antagonistic activity of saccharomyces boulardii against some pathogenic bacteria

The effect of frequent subculturing, freezing and lyophilization in presence of cryoprotectives on antagonistic activity and viability of saccharomyces boulardii was studied. Results indicated that early subculturings led to increasing the antagonistic activity but this activity fell down gradually and diminished after 10 -11 of subculturing which indicated the cytoplasmic responsibility i.e., could be coded by plasmids or virus-like particles. Freezing at -20°C had no effect on the viability in the presence of cryoprotectives like skim milk powder, Mg-stearate or without them, since the cultures recovered at 99-99.2% after [4] days. Lyophilization had very overt effect on viability .Skim milk provided the best protection [8% reduction] followed by using distilled water and Mg-stearate .Saline had the greatest effect and caused [15% reduction]. Storage results of lyophilized samples at room temperature and refrigerator showed that skim milk was the best at both temperatures followed by distilled water, saline and then Mg-stearate which showed the highest reduction in viable count of yeast