First discovered in 1894 in Hong Kong by Alexandre Yersin and Shibasaburo Kitasato, the genus Yersinia currently includes 18 species. Of these, only three have been identified as human pathogens: Y. pestis, Y. pseudotuberculosis, and Y. enterocolitica. While Y. pestis…
The genus Yersinia includes at least 19 described species, of which 3 are important human pathogens. Yersinia enterocolitica and Yersinia pseudotuberculosis are enteric pathogens usually acquired through ingestion of contaminated food or water. The third species, Yersinia pestis, causes plague.…
Pasteurella are gram-negative coccobacilli that inhabit the oral cavity and gastrointestinal tract of many animals and cause various infectious problems, including septicemia and pneumonia. In humans infection is most often caused by dog and cat bites, resulting in cellulitis, subcutaneous…
Francisella tularensis is a gram-negative pathogen primarily of animals and occasionally of humans. The disease is now recognized as tularemia in most areas of the world, but it has been called rabbit fever, deer fly fever, Francis disease, and market…
Brucellosis is the most frequently encountered worldwide zoonotic disease, which can be acquired from sheep, goat, cattle, swine, and other animals and transmitted to humans. Each year half a million new human brucellosis cases cause serious consequences on health and…
Haemophilus influenzae Description of the Pathogen H. influenzae is a small, nonmotile, non–spore-forming bacterium and a pathogen of humans found principally in the upper respiratory tract, first reported by Pfeiffer in 1892. The sensational claim that it was the primary…
Revised August 2, 2021 Reviewed for currency January 14, 2021 The term dysentery was used by Hippocrates to indicate a condition characterized by the frequent passage of stool containing blood and mucus, accompanied by straining and painful defecation. It was…
Salmonellae are named for the pathologist Salmon, who was involved in the first isolation (by Theobald Smith) of Salmonella choleraesuis from the porcine intestine. Salmonella are effective commensals and pathogens that cause a spectrum of diseases in humans and animals,…
Acinetobacter, an aerobic, catalase-positive, oxidase-negative, gram-negative coccobacillus, was first described in 1911, but the initial description of the taxonomy of this diverse species was not published until 1986. Ubiquitous in nature, the 54 species of the genus Acinetobacter are associated…
Revised August 10, 2021 The genus Burkholderia is currently composed of many species, but only three are notable pathogens for humans or animals: the former B. cepacia complex (described in Chapter 220 ), B. pseudomallei (the agent of melioidosis), and…