Investigation and sequencing of urease gene of H. pylori cocoid forms after exposure to different environmental conditions

Abstract number: 1734_88

Can F., Karahan Z.C., Dolapci I., Demirbilek M., Tekeli A., Arslan H.

Objectives: The aim of this study was to investigate whether convertion to the coccoid form under different environmental conditions resulted in sequence differences in the Urease A gene in H. pylori strains

Methods:Helicobacter pylori standart strain NTCC 11637 was used in this study. Transformation of the bacteria from helical to coccoid form was carried out with different techniques; exposure to amoxicillin, cold starvation, aerobiosis and aging of the culture. Urease activity was measured by rapid urea test. DNA was extracted from all samples by using Nucleospin DNA extraction kit (Clontech, CA). Urease A gene was amplified by using the primers HPU1 (GCC AAT GGT AAA TTA GTT CC) and HPU2 (GTA AAA ACA ATT AAG GAG). Bi-directional sequence analysis was performed by using one of the primers in each run by ABI Prism 310 DNA sequencer.

Results: Urease activity was determined in spiral and coccoid forms of H.  pylori. All samples yielded 411 bp amplimer by polymerase chain reaction. For all sequence comparisons, spiral form of H. pylori 11637 was used as the Standard. The sequence of the Standard strain was compared to the sequence in GenBank (accession number M60398). The standard strain had 6 silent mutations when compared to the Genbank sequence. All the sequences of the coccoid forms had the same silent mutations with the spiral shaped standard strain and the sequences of all the samples were identical.

Conclusion: Coccoid forms of H. pylori had urease activity. Convertion to coccoid form in various environmental conditions did not result in any change in the amplified region of the Urease A gene of the H. pylori.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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