When the Campylobacter enters the gut the HCl secreation in the gastric acid causes the difficulty for the bacteria to survive at the low PH. C. jejuni is rapidly killed by hydrochloric acid at pH 2.3, indicating that gastric acid is an effective barrier against infection . It can survive for 2 to 5 weeks in bovine milk or unpasteurized milk and water stored at 4 degree celcius and causes the infection when human ingest these substances. The campylobacter lacks fimbriae and finds difficult to attach with the gut mucosa. But it might use adhesins for the attachment.
Campylobacter gets attached to proximal part of the small intestine and secreate the toxins and activating the bowel movements and resulting in initiation of the diarrhoea.
Sometimes the campylobacter enters the epithelial tissue of the intestine and causes dysfunction of the intestine resulting in the bloody diarrhoea and causes inflammation of the gut cell.
They also enters the mesenteric lymph nodes and also lamina propria. the bacteria prevents the integration of the phagolysosomes, and the release of myeloperoxidase. And the bacteria is very much intelligent and it knows the way for its survival within the macrophages and it enters the reticuloendothelial cells that is nothing but the blood cell and causes septicemia.
Campylobacter increases the release of myoelectric potentials and causes the increase in bowel movements. These results in disordered peristalsis and disorderd flow which favour the multiplication of the bacteria.
Bacterial toxins in general have been conveniently classified as either membrane damaging, such as hemolysins and phospholipases, or intracellular acting. The toxins binds to the plasma membrane. The toxins produced by the campylobacter includes enterotoxin and cytotoxins.
The enterotoxin enhances the activity of the adenyl cyclase in the gut mucosa and also disrupts the activity of the ion transport in the small intestine. The enterotoxins are the heat labile proteins that is the action of those proteins are disrupted at the 56 degree celsius for 1 hour and 96 degree Celsius for 10 minutes.