Cytopathic effect of coccoid forms of Helicobacter pylori in Albino rats and Swiss mice

The effect of coccoid forms of a vaculating cytotoxin A positive Helicobacter pylori strain on Mus musculus (Swiss mice) and Rattus norvegicus (Albino rats) was studied. Two groups of Swiss mice and Albino rats were used. The first group of mice and rats was orally inoculated with coccoid forms of Helicobacter pylori, whereas, the second group of mice and rats were untreated and used as a control. The animals that had been orally inoculated with a total count of 7.0x10 bacterial cell / ml died after 5-7 days of inoculation (mice), whereas, rats died after 7-9 days. Symptoms of mouth ulcers, darkening of the ventral part and peripheries and loss of weight were apparent, in addition to slow movement and general weakness compared to the control group. Histological examination of the stomach of the inoculated animals showed marked degeneration of the epithelial lining membrane and dark dense bodies most probably coccoid forms inside gastric glands. In addition dialated blood vessel, degenerated, vacuolated fused cells with coccoid forms and intravascular haemolysis were observed. These findings may indicate the toxicity of coccoid forms of Helicobacter pylori and hence their possible pathogenic role in humans. [Rajaa M. Milyani. Cytopathic effect of coccoid forms of Helicobacter pylori in Albino rats and Swiss mice. Journal of American Science 2011; 7(6):1087-1092]. (ISSN: 1545-1003). http://www.americanscience.org.