Plesiomonas shigelloides is a Gram-negative, rod-shaped bacterium as observed through microscopy using a microscope such as biological compound microscope. It has been isolated from freshwater, freshwater fish and shellfish and from numerous types of animals comprising of cattle, swine, cats, monkeys, vultures, and toads among others. Majority of human Plesiomonas shigelloides contaminations are alleged to be waterborne. The organism may be emergent in unsanitary water, as examined by means of microscopy under a microscope such as biological compound microscope that has been utilized as drinking water, recreational water, or water utilized to rinse foods that are eaten without cooking or heating. The consumed Plesiomonas shigelloides organism does not always initiate disease in the host animal but can inhabit temporarily as a transitory, noninfectious member of the intestinal flora as examined using microscopy under a biological compound microscope. It has been isolated from the feces of patients with diarrhea, but is also at times isolated from healthy persons. It cannot yet be considered a specific factor of human disease, although its linkage with human diarrhea and the virulence aspects it displays make it a prime candidate, which have been viewed by means of microscopy using a microscope like the biological compound microscope. Gastroenteritis is the illness with which Plesiomonas shigelloides has been incriminated. Plesiomonas shigelloides gastroenteritis is typically a mild self-limiting illness with fever, abdominal pain, chills, nausea, diarrhea, or regurgitation; signs may start from twenty to twenty-four hours after ingestion of infected food or water. Diarrhea is watery, non-mucoid, and non-bloody as examined through microscopy under a microscope such as biological compound microscope. In serious cases, diarrhea may be greenish-yellow, foamy, and blood tinged. Duration of disease in healthy people may be one to seventeen days. The infectious dose is assumed to be moderately high, at least higher than one million organisms. The pathogenesis of Plesiomonas shigelloides contamination is not known. The organism is alleged of being toxigenic and intrusive. Its importance as an enteric or intestinal pathogen is assumed because of its predominant isolation from feces of patients with diarrhea as examined by means of microscopy using a microscope such as biological compound microscope. It is determined by common bacteriological analysis, serotyping, and antibiotic sensitivity analysis. Majority of Plesiomonas shigelloides contaminations take place in the summer months and correlate with ecological infection of freshwater. The typical route of transference of the organism in sporadic or epidemic instances is by consumption of infected water or raw shellfish. Majority of Plesiomonas shigelloides strains connected with human gastrointestinal disease have been from feces of diarrheic patients living in tropical and subtropical regions. Such contaminations are rarely noted in the U.S. or Europe because of the self-limiting nature of the illness. Plesiomonas shigelloides contamination may cause diarrhea of one to two days duration in healthy adults. Nevertheless, there may be high fever and chills and protracted dysenteric manifestations in babies and children below fifteen years of age. Extra- intestinal complications such as septicemia and death may happen in people who are immunocompromised or severely ill with cancer, blood disorders, or hepatobiliary illness.