Abstract
Helicobacter pylori is a spiral bacillus that can also adopt a coccoid form, a morphology associated with antibiotic resistance and the ability to withstand unfavorable environmental conditions. The relationship between coccoid forms, virulence, and the development of gastroduodenal diseases remains unclear. Therefore, this study aimed to determine the association between virulence and the induction of coccoid forms in H. pylori isolates from patients in Antioquia, Colombia. DNA from 30 clinical isolates was extracted, and the vacA and cagA genes were amplified to classify strains into high, intermediate, or low virulence groups. Four methodologies-each with specific modifications-were evaluated to induce coccoid forms. Bacterial morphology was assessed by optical microscopy, and coccoid cells were quantified using ImageJ. The association between virulence level and coccoid induction was analyzed using the Mann-Whitney U test. Before induction, cultures contained more than 90% spiral forms. The solid medium protocol under aerobic conditions was identified as the fastest in promoting coccoid conversion. After induction, high-virulence isolates showed a higher proportion of coccoid forms (72.6%) compared with low-virulence isolates (49.6%). A significant association was observed between virulence level and the induction of coccoid forms (p = 0.014). The findings suggest a relationship between the presence of vacA and cagA genes and the ability of H. pylori to adopt coccoid morphologies as an adaptive response. However, variability among induction protocols may introduce methodological biases and contribute to divergent interpretations of the biological role of coccoid forms. Further studies are needed to determine whether recurrences represent recrudescence or reinfection and to clarify the role of coccoid forms.