Biosafety Levels (BSL-1, BSL-2, BSL-3 and BSL-4)

Biosafety Levels

Definition and Introduction Biosafety is the prevention of risk to human health and safety, and the conservation of the environment and the pathogen, as a result of the use for research and commerce of infectious or genetically modified organisms. Biosafety is an important concept in microbiology as bio-related research activities may involve manipulation of microbial, animal, or plant cells which …

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Phases of Clinical Trials for Drugs and Vaccine Development

Phases of Clinical Trials for Drugs and Vaccine Development

In clinical research, clinical trials are a type of research experiment done on people aiming at finding a solution to a disease. These trials include studies of diagnostic tests, treatments, and monitoring and evaluation of the human health outcomes. The interventions of clinical trials include: Drugs Vaccines Biological products Surgical and radiation procedures Medical devices Preventive treatment (vaccines) Behavioral treatment. …

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Hand washing steps and guidelines by WHO and CDC with video

Introduction basic hygiene practices: Handwashing Basic hygiene is a mechanism of practicing and maintaining cleanliness. Poor hygienic methods have an extreme impact on causing infections ranging from skin infections to respiratory tract infections and gastrointestinal infection.  Most respiratory and gastrointestinal infections have been associated more often than usual that they are transmitted through a lack of or poor hand washing …

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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 agent may be transmitted from …

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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 A/E cytopathology, resembling EPEC strains. …

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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 of the intestines causing them …

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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 defined as any person, animal, …

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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 cells in an AA pattern. …

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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 and clinical outcomes. Most infections …

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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 contains many chemicals from which …

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