helicobacter pylori infection is a bacterial cause of
Helicobacter pylori Helicobacter pylori, previously Campylobacter pylori, is a gram-negative, microaerophilic bacterium found usually in the stomach. It was identified in 1982 by Australian scientists Barry Marshall and Robin Warren, who found that it was present in a person with chronic gastritis and gastric ulcers, conditions not previously believed to have a microbial cause. It is also linked to the development of duodenal ulcers and stomach cancer. However, over 80% of individuals infected with the bacterium are asymptomatic, and it may play an important role in the natural stomach ecology.[7]
Salmonella Salmonella species are intracellular pathogens:[4] certain serotypes cause illness. Nontyphoidal serotypes can be transferred from animal-to-human and from human-to-human. They usually invade only the gastrointestinal tract and cause Salmonella food poisoning; symptoms resolve without antibiotics. However, in sub-Saharan Africa they can be invasive and cause paratyphoid fever, which requires immediate treatment with antibiotics. Typhoidal serotypes can only be transferred from human-to-human, and can cause Salmonella food poisoning, typhoid fever and paratyphoid fever.[5] Typhoid fever occurs when Salmonella invades the bloodstream—the typhoidal form; or in addition spreads throughout the body, invades organs, and secretes endotoxins—the septic form. This can lead to life-threatening hypovolemic shock and septic shock and requires intensive care including antibiotics.