title: Assessment of cagE and babA mRNA expression during morphological conversion of Helicobacter pylori from spiral to coccoid.
abstract: Helicobacter pylori (H. Pylori) is an actively dividing spiral bacterium that changes to coccoid morphology under stressful environments. The infectivity of the coccoids is still controversial. The aim of this study was to determine the viability and expression of two important virulence genes (babA and cagE), in antibiotic-induced coccoid forms. Three strains of H. pylori, the standard 26695 and two clinical isolates (p1, p2) were converted to coccoid form by amoxicillin. Coccoids were identified according to Gram-staining and microscopic morphology. The viability of the cells was analyzed by flow cytometry. The expression of cagE and babA in coccoid forms were evaluated and compared to the spirals by quantitative PCR assay. The coccoid forms were developed after 72 h exposure of H. pylori to ½ MIC of amoxicillin, and the conversion form was completed (100 %) at 144 h in all of three isolates. Flow cytometry analyses showed that the majority of the induced coccoids (90-99.9 %) were viable. Expression of cagE and babA was seen in coccoids; however, in lower rate (cagE, ~3-fold and babA, ~10-fold) than these in spiral forms. Coccoid forms of two clinical isolates significantly expressed higher rate of cagE and babA than standard 26695 strain (P = 0.01). These results suggest that the induced coccoid form of H. pylori is not a passive entity but can actively infect the human by expression of the virulence genes for long time in stomach and probably play a role in chronic and severe disease.
authors.affiliation: Department of Microbiology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Farkhondeh
authors.initials: F
authors.lastname: Poursina
authors.forename: Jamshid
authors.initials: J
authors.lastname: Faghri
authors.forename: Sharareh
authors.initials: S
authors.lastname: Moghim
authors.forename: Hamid
authors.initials: H
authors.lastname: Zarkesh-Esfahani
authors.forename: Bahram
authors.initials: B
authors.lastname: Nasr-Esfahani
authors.forename: Hossein
authors.initials: H
authors.lastname: Fazeli
authors.forename: Akbar
authors.initials: A
authors.lastname: Hasanzadeh
authors.forename: Hajieh Ghasemian
authors.initials: HG
authors.lastname: Safaei
mesh_terms: D018829:Adhesins, Bacterial / Q000096:biosynthesis* / Q000235:genetics; D000658:Amoxicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D016481:Helicobacter Infections / Q000382:microbiology; D016480:Helicobacter pylori / Q000166:cytology* / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D006801:Humans; D050296:Microbial Viability / Q000187:drug effects; D008853:Microscopy; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D018829:Adhesins, Bacterial; D000900:Anti-Bacterial Agents; C400429:BabA protein, Helicobacter pylori; D001426:Bacterial Proteins; C103937:PicB protein, Helicobacter pylori; D012333:RNA, Messenger; D000658:Amoxicillin