Definition Shigellosis results from inflammation of the large intestine due to infection with bacteria of the genus Shigella . Clinical presentation is either with acute watery diarrhea or bloody diarrhea, known as dysentery, and is commonly accompanied by fever. Shigellosis…
Definition Many of the more than 2500 serovars (also called serotypes) of Salmonella enterica subspecies enterica infect humans and cause a range of clinical conditions from asymptomatic intestinal carriage to intestinal infection to invasive disease with extraintestinal complications. Each serovar…
Acinetobacter Spp Definition The Pathogen Acinetobacter spp are gram-negative, aerobic, coccobacillary bacteria, which are generally non–lactose-fermenting, nonfastidious, catalase positive, oxidase negative, and nonmotile, though their description of being “nonmotile” is questioned. The Gram stain appearance of Acinetobacter spp is highly…
Pseudomonas Infection Definition Infections due to Pseudomonas spp are caused by members of the family Pseudomonadaceae. The Pseudomonadaceae is a group of gram-negative rods, including P. aeruginosa , the most frequently recovered human pathogen in the family. Other Pseudomonas s…
Definition The Enterobacterales are an order of gram-negative bacilli that are responsible for a broad range of infections in humans and in animals. They may be motile or nonmotile, depending on the species. They are aerobic or facultatively anaerobic in…
Definition Bacteria belonging to the species Escherichia coli are a normal component of the intestinal microbiota ( Chapter 257 ). The majority of E. coli are harmless commensals, but specific isolates have acquired pathogenicity genes that enable them to cause…
Definition Campylobacter jejuni is one of the most commonly recognized bacterial causes of diarrhea in developed and underresourced nations. More than 95% of campylobacter isolated in developed countries are C. jejuni or C. coli . However, other Campylobacter species are…
Cholera Definition Cholera is a dreaded epidemic diarrheal disease caused by Vibrio cholerae serogroup O1 and, since 1992, by the new serogroup O139. The disease is characterized by acute, large-volume watery diarrhea. In its more severe form, a person may…
Haemophilus Influenzae Definition Haemophilus refers to the bacteria’s requirement for specific blood components for growth. In the respiratory tract, which is the primary site of colonization for most Haemophilus species, the most common infections include otitis media, sinusitis, bronchitis, and…
Definition Chancroid is a sexually transmitted disease that is characterized by painful genital ulcers and inguinal lymphadenitis caused by Haemophilus ducreyi . H. ducreyi also is a major cause of nonsexually transmitted cutaneous ulcers in children who live in regions…