The genus Kingella belongs to the Neisseriaceae family in the β-subclass of the Proteobacteria, and the genus currently comprises five recognized species. Kingella potus has been isolated from an infected animal bite in an adult, the recently described K. negevensis…
Since the discovery of Helicobacter pylori and the demonstration of its causal relationship with human gastroduodenal disease, investigators have identified numerous non− Helicobacter pylori Helicobacter (NHPH) species. These other Helicobacter spp. are frequently found in domestic and wild animals and…
Helicobacter pylori infection is ubiquitous among humans. , Despite declining prevalence in developed countries, H. pylori continues to be one of the most common human infections worldwide, affecting up to 90% of the population in developing nations. Transmission primarily occurs…
Of the Haemophilus species, H. influenzae causes by far the most human disease. Several other members of this genus, however, cause clinical illness. These include H. influenzae biogroup aegyptius , H. ducreyi, H. parainfluenzae, H. pittmaniae, H. sputorum, H. haemolyticus,…
Haemophilus influenzae was first isolated by Pfieffer during the 1889 influenza pandemic. For a time, H. influenzae was believed to be the causative agent of influenza and originally was called the influenza bacillus. However, subsequent studies demonstrated the fallacy of…
Description of Pathogen and Epidemiology Francisella tularensis, the etiologic agent of tularemia, is a small, fastidious, non−spore-forming, strictly aerobic gram-negative coccobacillus, which is nonmotile and nonpiliated and has a thin capsule composed mostly of lipid. Tularemia is a zoonotic disease;…
Description of the Pathogens The family Anaplasmataceae is classified in the order Rickettiales and currently contains five genera and two candidate genera of obligate intracellular bacteria. Four of the genera contain members that are known to infect humans: Anaplasma ,…
The Pathogen Q fever (or “query” fever) is caused by the intracellular bacterium Coxiella burnetii, which belongs to the order Legionellales, family Coxiellaceae. C. burnetii primarily is a zoonotic pathogen. The organism can be present in high concentrations in the…
The Pathogen Chlamydia psittaci (also known as Chlamydophila psittaci ) is a gram-negative obligate intracellular zoonotic bacterium that causes both systemic infection and pneumonia, often referred to as psittacosis or ornithosis ( Fig. 168.1 ). Originally named parrot fever because…
The Pathogen and Pathogenesis Chlamydiae are obligate, intracellular, nonmotile, gram-negative bacteria with a unique biphasic developmental cycle consisting of extra- and intracellular forms. Chlamydiae have an outer membrane that contains lipopolysaccharide (LPS) and membrane proteins. Peptidoglycan is present in the…