The genus Capnocytophaga consists of nine or more gram-negative fastidious species that typically reside as normal flora in the oral cavities of humans and other vertebrates including dogs and cats. Members of this genus can cause serious life-threatening infections in…
Reviewed for currency January 14, 2021 History Legionnaires’ disease (LD) is an acute pneumonic illness caused by gram-negative bacilli of the genus Legionella , the most common of which is Legionella pneumophila (Lp). Pontiac fever (PF) is a febrile, nonpneumonic,…
Rat-bite fever is a rare systemic febrile illness typically transmitted by the bite of a rat or other small rodent. The infection has a worldwide distribution and can be caused by either Streptobacillus moniliformis or Spirillum minus, bacteria commonly found…
History The first epidemic of whooping cough was described in 1578 by de Baillou, who wrote the following: “The lung is so irritated that, in its attempt by every effort to cast forth the cause of the trouble, it can…
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…