Helicobacter pylori is also a curved, flagellated, small gram-negative rod that is distinguished by being catalase, oxidase, and ureaase positive. The illness resolves spontaneously after a few days to 1 week. The diarrhea may be watery or dysenteric, with blood and pus in the stool. Clinical disease with C jejuni typically begins with lower abdominal pain, which evolves into diarrhea over a matter of hours. Despite the profound physiologic effects, there is no fever, inflammation, or direct injury to the bowel mucosa.Ĭampylobacter jejuni is the most common of the pathogenic Campylobacter species all of which are curved, motile gram-negative rods. The pathogenesis is solely due to the action of cholera enterotoxin secreted by V cholerae in the bowel lumen. Intestinal fluids pour out in voluminous bowel movements, which untreated rapidly leads to dehydration and electrolyte imbalance. Although many infections are asymptomatic, epidemic cholera produces the most dramatic watery diarrhea known. Reheated fried rice is the classic source.Vibrio cholerae is a motile (flagellated), comma-shaped oxidase-positive gram-negative rod that grows best on specialized media. Therefore, they may survive refrigerator temperatures or heating. These spore forming organisms can survive in harsh environments. īacillus cereus is a cause for food poisoning, with prominent vomiting.Many of them have become antibiotic resistant. Įnterococcal species within a genus of Streptococcus are gut commensals that are not ordinarily a problem until there is perforation of a viscus.parahemolyticus produces a less severe diarrhea, and contaminated shellfish are often implicated as the source. The organism is not invasive, but the toxin is powerful, and treatment requires prompt fluid and electrolyte replacement. cholera that elaborates a toxin causing a profuse watery diarrhea. Vibrio species involving the GI tract include the highly virulent V. Mesenteric lymph node involvement may occur, from where sepsis may originate. It often involves the terminal ileum, resulting in signs and symptoms resembling appendicitis.

Yersinia enterocolitica is a less common organisms in the family Enterobacteriaceae that can cause diarrhea (bloody if severe), abdominal pain, and vomiting. Aninmals are often implicated as the source. Ĭampylobacter jejuni can cause watery, and sometimes bloody, diarrhea and abdominal pain.Shigella organisms are virulent and can produce a necrotizing colitis and cause dysentery (a bloody diarrhea). The more common Salmonella enterica produces cramping abdominal pain and diarrhea it is often found in contaminated poultry products. Salmonella typhi starts as a gastrointestinal infection, but can become a systemic disease. coli constitutes a substantial amount of gut flora, then specific serotypes known to cause illness must be identified, such as serotype O157:H7 producing a shiga-like toxin that can lead to hemolytic-uremic syndrome (HUS). A standard stool culture identifies Salmonella, Shigella, Campylobacter, and Yersinia enterocolitica. Stool culture must be performed to identify specific pathogens, because stool contains an abundance of commensal bacteria.

Gram negative rods in stool