Original Articles
Copyright ©The Author(s) 2000. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 15, 2000; 6(2): 202-209
Published online Apr 15, 2000. doi: 10.3748/wjg.v6.i2.202
Agglutination of Helicobacter pylori coccoids by lectins
Mar Mar Khin, Jie Song Hua, Han Cong Ng, Torkel Wadström, Bow Ho
Mar Mar Khin, Jie Song Hua, Departments of Microbiology, Faculty of Medicine, National University of Singapore, 5, Science Drive 2, Singapore 117597, Republic of Singapore;
Han Cong Ng, Torkel Wadström, Bow Ho, Department of Medical Microbiology, Lund University, Solvegatan 23, S 22362 Lund, Sweden
Author contributions: All authors contributed equally to the work.
Correspondence to: Dr. Mar Mar Khin, MBBSc, PhD, Department of Biotechnology, School of IT & Applied Science, Temasek polytechnic, 21 Tampines Avenue 1, Singapore 529757. marmar@tp.edu.sg
Telephone: (65)-780-5343, Fax. (65)-789-6872
Received: December 22, 1999
Revised: January 6, 2000
Accepted: January 10, 2000
Published online: April 15, 2000
Abstract

AIM: To study the agglutination pattern of Helicobacter pylori coccoid and spiral forms.

METHODS: Assays of agglutination and agglutination inhibition were applied using fifteen commercial lectins.

RESULTS: Strong agglutination was observed with mannose-specific Concanavalin A (Con A), fucose-specific Tetragonolobus purpureas (Lotus A) and N-acetyl glucosamine-specific Triticum vulgaris (WGA) lectins. Mannose and fucose specific lectins were reactive with all strains of H. pylori coccoids as compared to the spirals. Specific carbohydrates, glycoproteins and mucin were shown to inhibit H. pylori lectin-agglutination reactions. Pre-treatment of the bacterial cells with formalin and sulphuric acid did not alter the agglutination patterns with lectins. However, sodium periodate treatment of bacterial cells were shown to inhibit agglutination reaction with Con A, Lotus A and WGA lectins. On the contrary, enzymatic treatment of coccoids and spirals did not show marked inhibition of H. pylori lectin agglutination. Interes tingly, heating of H. pylori cells at 60 °C for 1 h was shown to augment the agglutination with all of the lectins tested.

CONCLUSION: The considerable differences in lectin agglutination patterns seen among the two differentiated forms of H. pylori might be attributable to the structural changes during the events of morphological transformation, resulting in exposing or masking some of the sugar residues on the cell surface. Possibility of various sugar residues on the cell wall of the coccoids may allow them to bind to different carbohydrate receptors on gastric mucus and epithelial cells. The coccoids with adherence characteristics like the spirals could aid in the pathogenic process of Helicobacter infection. This may probably lead to different clinical outcome of H. pylori associated gastroduodenal disease.

Keywords: Helicobacter pylori; coccoids; lectin; gastric mucosa