Mode of Transmission of Diseases

Mode of Transmission of Diseases

Mode of Transmission of Diseases The traditional epidemiologic triad model holds that infectious diseases result from the interaction of agent, host, and environment. More specifically, transmission occurs when the agent leaves its reservoir or host through a portal of exit, is conveyed by some mode of transmission, and enters through an appropriate portal of entry to infect a susceptible host.  An infectious … Read moreMode of Transmission of Diseases

Shiga toxin-producing Escherichia coli (STEC)

Shiga toxin-producing Escherichia coli (STEC)

Shiga toxin-producing Escherichia coli (STEC) The Shiga toxin-producing E. coli (STEC), is also alternatively referred to as verocytotoxin-producing E. coli (VTEC), and enterohemorrhagic E. coli (EHEC). All members of this group are defined by the presence of Shiga toxin 1 (Stx1) or 2 (Stx2). Some but not all EHEC strains are LEE positive and form … Read moreShiga toxin-producing Escherichia coli (STEC)

Enterotoxigenic E. coli (ETEC)

Enterotoxigenic E. coli (ETEC)

Enterotoxigenic E. coli (ETEC) Enterotoxigenic E. coli (ETEC) is defined as containing the E. coli strains that elaborate at least one member of two defined groups of enterotoxins: heat-stable toxin (ST) and heat-stable toxin (LT). Enterotoxigenic Escherichia coli, or ETEC, is thus the name given to a group of E. coli that produces special toxins that stimulate the lining … Read moreEnterotoxigenic E. coli (ETEC)

Source and Reservoir of Infection

Source and Reservoir of Infection

Source and Reservoir of Infection The starting point for the occurrence of a communicable disease is the existence of a reservoir or source of infection. The source of infection is defined as “the person, animal, object or substance from which an infectious agent passes or is disseminated to the host (immediate source).” The reservoir is … Read moreSource and Reservoir of Infection

Enteroaggregative E. coli (EAEC)

Stages of pathogenesis of EAEC

Enteroaggregative E. coli (EAEC) Enteroaggregative E.  coli (EAEC) are a heterogeneous collection of strains characterized by their autoagglutination in a “stacked-brick” arrangement over the epithelium of the small intestine and, in some cases, the colon. EAEC strains are currently defined as  E. coli strains that do not secrete enterotoxins LT or ST and that adhere to HEp-2 … Read moreEnteroaggregative E. coli (EAEC)

E. coli Pathotypes- ETEC, EPEC, EHEC, EAEC, EIEC, DAEC

E. coli Pathotypes

E. coli Pathotypes- ETEC, EPEC, EHEC, EAEC, EIEC, DAEC Escherichia coli (commonly abbreviated E. coli) is a Gram-negative, facultative anaerobic, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms (endotherms). Human Escherichia coli strains are classified as commensal microbiota E. coli, enterovirulent E. coli, and extraintestinal pathogenic E. coli (ExPEC) on the basis of their genetic features … Read moreE. coli Pathotypes- ETEC, EPEC, EHEC, EAEC, EIEC, DAEC

Types of Crystals in Urine

Types of Crystals in Urine

Types of Crystals in Urine Urine contains a large number of different chemicals. Under some circumstances, these chemicals may solidify into salt crystals. This is called crystalluria. Crystals have a characteristic refractile appearance. Testing for crystals in urine test is often part of a urinalysis, a test that measures different substances in the urine.  Normal urine … Read moreTypes of Crystals in Urine

Urinary Tract Infection (UTI)

Urinary Tract Infection

Urinary Tract Infection (UTI)- Types, Causative Agents, Pathogenesis, Symptoms, Complications, Risk Factors, Diagnosis, Treatment and Prevention A urinary tract infection (UTI) is an infection that affects part of the urinary tract. The urinary system is made up of the kidneys, ureters, the urinary bladder, and the urethra. Most UTIs are restricted to infection of the bladder (cystitis), though infection may occur in any area of … Read moreUrinary Tract Infection (UTI)