OBJECTIVES The significance of the coccoid forms of H. pylori is still controversial and the questions of whether these forms are viable and infective or degenerative are still open. We induced conversion from rod to coccoid forms and studied morphological changes and antigenic evolutions during this conversion and, thereby, elucidated the viability of coccoid forms. METHODS The H. pylori str...

conclusions induction of coccoid form of p. aeruginosa may be one of the important reasons for antibiotic treatment failure; therefore, prescribed dose of antibiotics should be carefully managed to prevent increasing antibiotic resistance and coccoid bacteria induction. results all used antibiotics at sub mic concentration had capability to induce coccoid bacteria. the highest rate of induced c...

To the Editor-Eaton et al. [1] recently described experiments with coccoid Helicobacter pylori in gnotobiotic piglets. This interesting study examined the colonization and the reversion from coccoid to bacillary H pylori within 2 weeks of inoculation. Piglets colonized with bacillary H pylori had more severe gastritis 2 weeks after inoculation than did those sacrificed 1 week after inoculation....

BACKGROUND Pseudomonas aeruginosa might be converted to coccoid bacteria under antibiotic stress. Bacterial conversion would increase resistance to antibiotics due to changes in cell wall crosslink or decreased metabolic activity. Morphology of P. aeruginosa under stress conditions (presence of antibiotics) can be changed to elongated bacilli, U shape and finally coccoid bacteria. Results of se...

Helicobacter pylori can transform from its normal helical bacillary morphology to a coccoid morphology. Since this coccoid form cannot be cultured in vitro, it has been speculated that it is a dormant form potentially involved in the transmission of H. pylori and in a patient's relapse after antibiotic therapy. In this study we determined the effects of aging, temperature, aerobiosis, starvatio...

To determine the pathological significance of the coccoid form of Helicobacter pylori, its adhesion to and induction of secretion of interleukin-8 (IL-8) by gastric epithelial (MKN45) cells were studied. By flow cytometry, the adhesion of the coccoid form to MKN45 cells was significantly lower than that of the helical form. The monoclonal antibody A20 recognising lipopolysaccharide of H. pylori...

Helicobacter pylori (H. pylori) can infect into the epithelial cell to cause benign or malignant disorders. Under stressful environment, a spiral form of H. pylori is transformed into a coccoid form. The infectivity of the coccoid form is still controversial. Since spiral forms are transformed into two types of coccoid forms via different mechanisms, the infectivity of the two types of coccoid ...

An increasing number of studies support a potential role for coccoid forms in Helicobacter pylori infection. Evidence for this was obtained through scanning microscopy, genetic analysis for virulence traits, examination of the presence and activity of key enzymes, and other methods. We studied the serum immunoglobulin G responses to coccoid H. pylori forms by enzyme-linked immunosorbent assay (...

Helicobacter pylori exists in two distinct forms, rod shaped or coccoid, in stomachs of infected patients. Based on in vitro proteome comparisons, there are no detectable coccoid-specific proteins, which argues against the specific adaptation of coccoid Helicobacter to distinct biological functions, such as enhanced persistence or transmission to other hosts.

Human gastric epithelial immortalized GES-1 cells were infected with spiral and coccoid Helicobacter pylori. Scanning electron microscopy was used to determine the ability of the two forms of H. pylori to adhere to GES-1 cells. GES-1 cell apoptosis induced by coccoid and spiral H. pylori was analysed using flow cytometry. A cDNA microarray for 22,000 human genes was used to identify the gene-ex...