to adhere and colonize human intestinal mucosa/ epithelial cells is a major criterion for selection as probiotic or commensal bacteria. Adhesion to the host tissues is a prerequisite first step of bacterial colonization which is generally mediated by cell surface adhesion proteins . Adhesion of probiotic bacteria not only help in persistence of bacteria in gut but also participate in pathogen exclusion by competition and blocking of their binding sites at the mucosa . This adherence to epithelial cells on mucosal surface is modulated by specific binding of microbial adhesins. Lactobacilli adhesins can be broadly classified according to their targets in the intestinal mucosa (i.e. mucus, extracellular matrix), based on their localization in the bacterial surface (i.e. surface layer proteins) and/or to the way how they are anchored to bacterial surface (i.e. sortase-dependent proteins, N/C terminal anchored).
The movement of the endocytosed protein which is destined for the apical surface to fuse with and also the movement of extracellular materials from one side of the epithelial cells to another can be termed as transcytosis. With respect to concept, transcytosis can be grouped into three processes namely; endocytosis, exocytosis and transcellular transport (Pravda,2011). Though transcytosis is tightly controlled by the cell it also has the potential for transepithelial movement of bacteria and other pathogens, hence it sometimes becomes an etiologic factor in the body(Pravda,2011). Trancytosis occurs in hepatocytes and this phenomenon is a typical example of transcellular transport . Here the apical membrane form bile and the basolateral membrane face blood.
Introduction Our world is composed of many bacteria’s’ that can either help or destroy us. Therefore, its’s imperative to learn and study them. The purpose of the lab was to put into action the methods that have been learned in the laboratory to determine our unknown bacteria. Bacteria’s can have different features, shapes, and or arrangements that help microbiologist determined their role in our life (whether they are good or bad for humans).
A very important example of a ribozyme is the ribosome, a large assembly of proteins and catalytically active RNA molecules responsible for the synthesis of proteins in the cell. The structure of the active site is specific to the reaction that it catalyzes, with groups in the substrate
The term cell membrane was coined by C.Nageli and C.Cramer in 1855 and the term plasmalemma has been given by J.Q.Plowe in 1931. PLASMA MEMBRANE DEFINITION Plasma membrane can be defined as a biological membrane or an outer membrane of a cell, which is composed of two layers of phospholipids and embedded with proteins. It is a thin semi permeable membrane layer, which surrounds the cytoplasm and other constituents of the cell. PLASMA MEMBRANE STRUCTURE 1.
(15 pts) There are three parts of the immune system that consist of the body’s natural barriers, the innate immune response and the adaptive immune response. The skin and mucosal surfaces form barriers against infection. When bacteria enters through a break in the natural barrier of the skin, it is first introduced to antimicrobial peptides under the surface of the skin that is supposed to kill bacteria,
Through the reverse transcription, the viral RNA is transcribed to viral double-stranded DNA. This process is catalyzed by an RNA-dependent DNA polymerase, also known as reverse transcriptase, which is encoded by the viral genome, which is integrated within the cell genome by integrase. This protein cleaves nucleotides of each 3’ ends of the double helix DNA creating two sticky ends, transfers the modified provirus DNA into the cell nucleus and facilitates its integration into the host genome. The integration of proviral DNA and the expression of the provirus require that target cell is in an activated state. Monocytes/macrophages, microglial cells, and latently infected quiescent CD4+ T-cells contain integrated provirus and are important long-living cellular reservoirs of HIV.
Faculty of pharmacy Microbiology Department Assignment Topic: Phage as medical alternative Course Title: General Microbiology and Immunology Course Code: PM204 Lab Group: E1 Prepared By: Ahd Mohamed Abdelmoniem Fahmi-175063 Due Date: 20-10-2017 Definition of phage: Phage is a short for bacteriophage, which is virus that lives inside bacteria, and is a piece of nucleic acid RNA or DNA which is bordered by a coat that consists of capsid proteins.
Natural transformations in which the uptake, integration and expression of extracellular DNA occurs under natural populations of bacteria. Through this mechanism bacteria can acquire DNA from foreign species which are not accessible to mobile genetic elements or bacteriophages. The requirement for this process is that, the bacteria should first develop a physiological state of competence. Some bacterial species, such as Neisseria gonorrhoeae and Haemophilus influenzae, are competent to accept DNA, whereas some others, such as Bacillus subtilis and Streptococcus pneumoniae, become competent after reaching a certain physiological stage in their life cycle (22,15). 2.
Dendritic cells ‘present’ antigens to T cells, causing T cells to proliferate into either helper T cells, which aid B cell activation, or cytotoxic T cells, which leave the lymph node via the efferent vessels (Milling n. d.) to areas of antigenic activity in the body. Juxtaposition of B and T cells with dendritic cells is essential for their activation (Mondino et al 1996). The medulla contains B cells, macrophages, and antibody-producing plasma cells which have migrated from the cortex, all embedded within a reticular fibre and cell network. From the medullary sinuses, the filtered lymph drains into one or two efferent lymphatic vessels located at the hilum (depression in the concave side of the ‘bean shape’) (blood vessels also enter and exit the node here).
Cellular world can be divided into two types, depending on the presence of nuclei inside cells. Eukaryotic cells have a well-defined nucleus surrounded by a nuclear envelope, whereas prokaryotic cells lack this compartment. All bacteria are prokaryotes. Bearze (2015) provided information about the Bacterial Cell Structure and Function. Vibrio cholerae is a gram negative, non-spore forming, curved rod that is oxidase positive.
Inducers bind to the repressors and they also regulate gene expression. In the process of identifying the three strains of E.coli, ONPG (ortho-nitrophenyl b-D galactoside) was used as an indicator. ONPG is a substrate that can detect B-galactosidase, and when it does, it turns yellow. Sarkosyl was also a detergent used in the lab to lyse open cells. In the lab we predicted that the E.coli wild type would be clear for distilled water and sucrose but yellow for lactose.