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Introduction to Bacteriology and Bacterial Structure/Function
INTRODUCTION TO BACTERIOLOGY AND BACTERIAL STRUCTURE/FUNCTION LEARNING OBJECTIVES To describe historical landmarks of medical microbiology To describe Koch’s Postulates To describe the characteristic structures and chemical nature of cellular constituents that distinguish eukaryotic and prokaryotic cells To describe chemical, structural, and functional components of the bacterial cytoplasmic and outer membranes, cell wall and surface appendages To name the general structures, and polymers that make up bacterial cell walls To explain the differences between gram negative and gram positive cells To describe the chemical composition, function and serological classification as H antigen of bacterial flagella and how they differ from flagella of eucaryotic cells To describe the chemical composition and function of pili To explain the unique chemical composition of bacterial spores To list medically relevant bacteria that form spores To explain the function of spores in terms of chemical and heat resistance To describe characteristics of different types of membrane transport To describe the exact cellular location and serological classification as O antigen of Lipopolysaccharide (LPS) To explain how the structure of LPS confers antigenic specificity and toxicity To describe the exact cellular location of Lipid A To explain the term endotoxin in terms of its chemical composition and location in bacterial cells INTRODUCTION TO BACTERIOLOGY 1. Two main threads in the history of bacteriology: 1) the natural history of bacteria and 2) the contagious nature of infectious diseases, were united in the latter half of the 19th century. During that period many of the bacteria that cause human disease were identified and characterized. 2. Individual bacteria were first observed microscopically by Antony van Leeuwenhoek at the end of the 17th century. -
Difference Between Hypersensitivity and Autoimmunity Key Difference – Hypersensitivity Vs Autoimmunity
Difference Between Hypersensitivity and Autoimmunity www.differencebetwee.com Key Difference – Hypersensitivity vs Autoimmunity Autoimmunity is an adaptive immune response mounted against self-antigens. In simple terms, when your body is acting against its own cells and tissues, this is called an autoimmune reaction. An exaggerated and inappropriate immune response to an antigenic stimulus is defined as a hypersensitivity reaction. Unlike autoimmune reactions that are triggered only by the endogenous antigens, hypersensitivity reactions are triggered by both endogenous and exogenous antigens. This is the key difference between hypersensitivity and autoimmunity. What is Hypersensitivity? An exaggerated and inappropriate immune response to an antigenic stimulus is defined as a hypersensitivity reaction. The first exposure to a particular antigen activates the immune system and, antibodies are produced as a result. This is called sensitization. Subsequent exposures to the same antigen give rise to hypersensitivity. Few important facts regarding the hypersensitivity reactions are given below They can be elicited by both exogenous and endogenous agents. They are a result of an imbalance between the effector mechanisms and the countermeasures that are there to control any inappropriate execution of an immune response. The presence of a genetic susceptibility increases the likelihood of hypersensitivity reactions. The manner in which hypersensitivity reactions harm our body is similar to the way that the pathogens are destroyed by immune reactions. Figure 01: Allergy According to the Coombs and Gell classification, there are four main types of hypersensitivity reactions. Type I- Immediate Type/ Anaphylactic Mechanism Vasodilation, edema, and contraction of smooth muscles are the pathological changes that take place during the immediate phase of the reaction. -
Ii Vasclitides
ا يمون وپات وژنز واسکوليتھااکلتا Vascliiitides: The Immunopa tho genes is دکتر محمدمھدی محمدی LMD, PhD, MPH ([email protected]) The 7th International 12th National Congress on Quality Improvement in Clinical Laboratories 28 Farvardin 1393 / 17April 2014 , Tehran, Iran A small spoonful of Terminology (in Farsi بيماريزايی) – .path·o·gen·e·sis, n • – the ppp(roduction and development of disease (events and reactions and other pathologic mechanisms) . Also, pa·thog·e·ny !?! (in Farsi بيماريزايی) _ .path·o·ge·nic·i·ty, n • – the disease-producing capacity of a pathogen. [PATHOGENIC + -ITY] • vir·u·lence, n. – the relative ability of a microorganism to cause disease; degree of pathogenicity. • Vasculitis, n. (vasculitides, plural) – a general term for vessel wall inflammation, systemic or localized, immune-mediated or directly invaded by microbes. • Infections may indirectly generate vasculitis, e.g. through IC formation or by X_reaction. Note that immunosuppressive therapy is only appropriate for --?– type! • WHAT R the IMMUNE MECHANISMS in VASCULITIS? افراط تعادل تفريط Immunodeficiency Allergy (& Infection) Defence Immunodeficiency Surveillance Autoimmunity (& Malignancy) Homostasis ?! Some Inter-related Concepts Immunological Vasculitis Hypersensitivity Auoimmunity Tolerance EDUCATION? Tolerance in different classic Txtbks of Immunology (Abbas, Benjamini, Janeway, Kuby, Roitt, Stites …) • Tolerance (by C&M Immunology): – Unresponsiveness of the adaptive immune system to antigens, as a result of inactivation or death of antigen-specific lymphocytes, induced by exposure to the antigens. – (()Active) Unresponsiveness of the (()HEALTHY) adappytive immune system to (selected) antigens, as a result of (i.e. MECHANISMS:) inactivation or death of antigen-specific lymphocytes, induced by exposure to those antigens. • Tolerance to self antigens is a normal feature of the adaptive immune system, but tolerance to foreign antigens may be induced undtiditiftider certain conditions of antigen exposure. -
Hypersensitivity Reactions (Types I, II, III, IV)
Hypersensitivity Reactions (Types I, II, III, IV) April 15, 2009 Inflammatory response - local, eliminates antigen without extensively damaging the host’s tissue. Hypersensitivity - immune & inflammatory responses that are harmful to the host (von Pirquet, 1906) - Type I Produce effector molecules Capable of ingesting foreign Particles Association with parasite infection Modified from Abbas, Lichtman & Pillai, Table 19-1 Type I hypersensitivity response IgE VH V L Cε1 CL Binds to mast cell Normal serum level = 0.0003 mg/ml Binds Fc region of IgE Link Intracellular signal trans. Initiation of degranulation Larche et al. Nat. Rev. Immunol 6:761-771, 2006 Abbas, Lichtman & Pillai,19-8 Factors in the development of allergic diseases • Geographical distribution • Environmental factors - climate, air pollution, socioeconomic status • Genetic risk factors • “Hygiene hypothesis” – Older siblings, day care – Exposure to certain foods, farm animals – Exposure to antibiotics during infancy • Cytokine milieu Adapted from Bach, JF. N Engl J Med 347:911, 2002. Upham & Holt. Curr Opin Allergy Clin Immunol 5:167, 2005 Also: Papadopoulos and Kalobatsou. Curr Op Allergy Clin Immunol 7:91-95, 2007 IgE-mediated diseases in humans • Systemic (anaphylactic shock) •Asthma – Classification by immunopathological phenotype can be used to determine management strategies • Hay fever (allergic rhinitis) • Allergic conjunctivitis • Skin reactions • Food allergies Diseases in Humans (I) • Systemic anaphylaxis - potentially fatal - due to food ingestion (eggs, shellfish, -
Immune Pathology Immune System Functions Reactivity to Tolerance Nonshared Ag to Self-Ag
Immune Pathology Immune system functions reactivity to tolerance nonshared Ag to self-Ag reduction pErVeRsIoN malfunction immunodeficiency hypersensitivity autoimmune diseases Hypersensitivity Hypersensitivity - excessive or inadequate manifestation adaptive immune of reactions Can manifest as local and systemic reactions Hypersensitivity Type Synonym Immunological mechanisms I IgE-mediated, anaphylactic, IgE-mediated degranulation of mast reaginic, HIS (blood cells dyscrasia) II antibody-dependent Cytotoxic antibodies activate cytotoxicity complement, which leads to cell lysis III immune complex Immune complexes activate leukocytes IV cell-mediated, delayed-type Cytokine production by hypersensitivity macrophages and lymphocytes V antibody-dependent Antibodies alter functional state of functional changes cells by interacting with its receptor Type I hypersensitivity • Speed of reaction - seconds or minutes • IgE-mediated • Chemical mediators of damage - vasoactive products of mast cells / basophils (histamine, arachidonic acid derivatives) • Mechanism - accumulation of of neutrophils, unstriated muscle spasm Type I hypersensitivity • bronchial asthma (some forms) • anaphylactic shock • Urticaria • Quincke's edema • dietary allergy • nasal allergy • allergic conjunctivitis Mast cell Аг Synthesis and secretion: leukotrienes (LTC4, LTB4), prostaglandins (PGD2), degranulation: IL-3, 4,5,6 histamine Platelet-activating factor serotonin (PAF) eotoxin Type I hypersensitivity Morphological manifestations IHS: • exudative alterative inflammation -
Medical Bacteriology
LECTURE NOTES Degree and Diploma Programs For Environmental Health Students Medical Bacteriology Abilo Tadesse, Meseret Alem University of Gondar In collaboration with the Ethiopia Public Health Training Initiative, The Carter Center, the Ethiopia Ministry of Health, and the Ethiopia Ministry of Education September 2006 Funded under USAID Cooperative Agreement No. 663-A-00-00-0358-00. Produced in collaboration with the Ethiopia Public Health Training Initiative, The Carter Center, the Ethiopia Ministry of Health, and the Ethiopia Ministry of Education. Important Guidelines for Printing and Photocopying Limited permission is granted free of charge to print or photocopy all pages of this publication for educational, not-for-profit use by health care workers, students or faculty. All copies must retain all author credits and copyright notices included in the original document. Under no circumstances is it permissible to sell or distribute on a commercial basis, or to claim authorship of, copies of material reproduced from this publication. ©2006 by Abilo Tadesse, Meseret Alem All rights reserved. Except as expressly provided above, no part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without written permission of the author or authors. This material is intended for educational use only by practicing health care workers or students and faculty in a health care field. PREFACE Text book on Medical Bacteriology for Medical Laboratory Technology students are not available as need, so this lecture note will alleviate the acute shortage of text books and reference materials on medical bacteriology. -
Hypersensitivity Reactions
Color code: Important in red Extra in blue Hypersensitivity Reactions For team error adjustments, click here Objectives ➤ To know that hypersensitivity reactions are over and excessive immune responses that can be harmful to the body in four different ways ➤ To be familiar with inflammatory processes in Type I hypersensitivity reaction that mediate allergic inflammation ➤ To recognize that Type II hypersensitivity deals with immune responses against antigens that are integral parts of the cell membrane and are usually associated with autoimmune disorders ➤ To know that Type III hypersensitivity reactions are mediated by immune complexes and cause vasculitis ➤ To describe Type IV hypersensitivity is a purely cell mediated immune response associated with chronic inflammation What is hypersensitivity? Hypersensitivity: is an undesirable Protective immunity: desirable reaction by the immune system. reaction. Gell—Coombs Classification of Hypersensitivity Reactions Type I: Type IV: IgE mediated Type II: Type III: IgG mediated IgG mediated T cell (most (destruction (immune mediated allergic of cells) complex) immunity reactions) Type I Hypersensitivity ● Known as immediate hypersensitivity (mins-hrs) or an allergic reaction that may develop into an anaphylactic* reaction (a severe and life-threatening form). Antibody - Allergic (atopic): IgE - Non Allergic: IgG Features Cells Involved - Mast cells - Eosinophils - Basophils Antigen - Allergen (low molecular weight & high solubility) Ex: Pollens, Dust mites, Injected allergen (sting venom from -
Hypersensitive Reactions
Hypersensitive reactions For B.Sc Life Sciences VI Sem Paper Immunology Teacher: Dr. Renu Solanki There Are Several Components of Type I Reactions 1. Allergens: The majority of humans mount significant IgE responses only as a defense against parasitic infections. After an individual has been exposed to a parasite, serum IgE levels increase and remain high until the parasite is successfully cleared from the body. The term allergen refers specifically to nonparasitic antigens capable of stimulating type I hypersensitive responses in allergic individuals. 2. REAGINIC ANTIBODY (IGE): Serum IgE levels in normal individuals fall within the range of 0.1–0.4 µg/ml; even the most severely allergic individuals rarely have IgE levels greater than 1 µg/ml. IgE was found to be composed of two heavy and two light chains with a combined molecular weight of190,000.The higher molecular weight as compared with IgG (150,000) is due to the presence of an additional constant-region domain (see Figure 4- 13). This additional domain (C H 4) contributes to an altered conformation of the Fc portion of the molecule that enables it to bind to glycoprotein receptors on the surface of basophils and mast cells. Although the half-life of IgE in the serum is only 2–3 days, once IgE has been bound to its receptor on mast cells and basophils,it is stable in that state for a number of weeks. IgE Crosslinkage Initiates Degranulation Type I Reactions Can Be Systemic or Localized SYSTEMIC ANAPHYLAXIS LOCALIZED ANAPHYLAXIS (ATOPY) -ALLERGIC RHINITIS: ALLERGIC RHINITIS: Results from the reaction of airborne allergens with sensitized mast cells in the conjunctivae and nasal mucosa to induce the release of pharmacologically active mediators from mast cells; these mediators then cause localized vasodilation and increased capillary perme- ability. -
Biochemistry Hypersensitivity IV and V
Description of Module Paper : 16 Immunology Module : 30 Hypersensitivity IV and V Principal Investigator Dr. Sunil Kumar Khare,Professor Dept. of Chemistry, I.I.T. Delhi Paper Coordinator Dr. M.N.Gupta, Emeritus Professor and Dept. of Biochemical Engg. and Content Writer Biotechnology, I.I.T. Delhi Content Reviewer: Dr. Prashant Mishra, Professor Dept. of Biochemical Engg. and Biotechnology, I.I.T. Delhi 1 Immunology Biochemistry Hypersensitivity IV and V Subject Name Biochemstry Paper Name 16 Immunology Module Name/Title 30 Hypersensitivity IV and V Dr. Vijaya Khader Dr. MC Varadaraj 2 Immunology Biochemistry Hypersensitivity IV and V 1. Objectives To understand the three types of class IV hypersensitivity reaction: contact dermatitis, tuberculin reaction and granulomatous hypersensitivity reaction. To explain how machanistically all the three types follow the same route. To learn how certain diseases caused by infectious agent have involvement of type IV hypersensitivity To understand type V hypersensitivity reactions which occur because of chronic stimulation 2. Concept map 3 Immunology Biochemistry Hypersensitivity IV and V Type IV hypersensitivity is also called delayed type as results are seen from 48 hrs-28 days ! In the three variants of type IV, the delay is of different time periods. We will also look at the type V hypersensitivity which was introduced as a separate class after Coombs and Geller classification. This hypersensitivity is involved in some autoimmune diseases. Contact with some substances can cause contact dermatitis. Injection of some antigens derived from infectious agents can be used as a test for hypersensitivity towards that microbe. When some microbes persist, it causes formation of granulomes. -
5 Allergic Diseases (And Differential Diagnoses)
Chapter 5 5 Allergic Diseases (and Differential Diagnoses) 5.1 Diseases with Possible IgE Involve- tions (combination of type I and type IVb reac- ment (“Immediate-Type Allergies”) tions). Atopic eczema will be discussed in a separate section (see Sect. 5.5.3). There are many allergic diseases manifesting in The maximal manifestation of IgE-mediated different organs and on the basis of different immediate-type allergic reaction is anaphylax- pathomechanisms (see Sect. 1.3). The most is. In the development of clinical symptoms, common allergies develop via IgE antibodies different organs may be involved and symp- and manifest within minutes to hours after al- toms of well-known allergic diseases of skin lergen contact (“immediate-type reactions”). and mucous membranes [also called “shock Not infrequently, there are biphasic (dual) re- fragments” (Karl Hansen)] may occur accord- action patterns when after a strong immediate ing to the severity (see Sect. 5.1.4). reactioninthecourseof6–12harenewedhy- persensitivity reaction (late-phase reaction, LPR) occurs which is triggered by IgE, but am- 5.1.1 Allergic Rhinitis plified by recruitment of additional cells and 5.1.1.1 Introduction mediators.TheseLPRshavetobedistin- guished from classic delayed-type hypersensi- Apart from being an aesthetic organ, the nose tivity (DTH) reactions (type IV reactions) (see has several very interesting functions (Ta- Sect. 5.5). ble 5.1). It is true that people can live without What may be confusing for the inexperi- breathing through the nose, but disturbance of enced physician is familiar to the allergist: The this function can lead to disease. Here we are same symptoms of immediate-type reactions interested mostly in defense functions against are observed without immune phenomena particles and irritants (physical or chemical) (skin tests or IgE antibodies) being detectable. -
Candida Albicans, 152 Ascaris Lumbricoides, 172 Borrelia
Index AIDS, 117 Arteritis C-s (Chiirg-Strauss) syndrome, CDC surveillance case giant cell (GCA), 218-219 213-214 definition for, 119 temporal,218-219 Candida albicans, 152 ocular manifestations of Arthritis Candidiasis, 152-153 infection with, 117-125 psoriatic, 207-208 Cataract surgery, 81-83 retinal manifestations of, rheumatoid, see Rheumatoid CDC surveillance case 119 arthritis definition for AIDS, 119 AKC (atopic keratoconjunc- AS (ankylosing spondylitis), Cell tivitis),188-189 198-200 aqueous, 19 Alkylating drugs, 72-73 Ascariasis, 172 defined,3-4 Amoebiasis, 162-163 Ascaris lumbricoides, 172 Chest radiograph, 50 Anaerobic endophthalmitis, Atopic keratoconjunctivitis Chorioretinitis, defined, 4 chronic, 269-270 (AKC), 188-189 Chorioretinopathy, ANCA autoantibodies, 49-50 Autoimmune uveitis, serpiginous, 248-249 Angle signs, 22-23 experimental (EAU), 241 Choroid disorders, 247-252 Animals causing uveitis, 182- Azathioprine, 73 Choroidal signs, 29 183 Choroiditis, 29 Ankylosing spondylitis (AS), defined,4 198-200 Bacterial diseases causing multifocal, and panuveitis Anterior chamber signs, 19- uveitis, 134-144 (MCP) syndrome, 247-248 20 Bacterial endophthalmitis, punctate inner (PIC), 248 Anterior uveitis, 9 infectious, 267-269 vitiliginous, 240 Antiphospholipid antibodies Band keratopathy, 17, 19 Chiirg-Strauss (C-S) (APLA),49 BARN (bilateral acute retinal syndrome,213-214 APMPPE (acute posterior necrosis syndrome), 115- Cicatricial pemphigoid (CP), multifocal placoid 117 191-193 pigment epitheliopathy), Beh-;et's disease, 200-202 -
LEARNING from LEPROSY Be Enjoyed by 50%Of the Urbanpopulation, but Only 15% Monoclonal Anti-Interferon (IFN)-Y Antibodies
0022- 1767/86/137 1 -0OOiSO2.00/0 THEJOURNAL OF 1MMUNOLoGY Vol. 137. No. 1. July 1, I986 Copyright 0 1986 by The American Association of Immunol~lsts Prlnted In U.S.A. American Associationof Immunologists PRESIDENTIALADDRESS LEARNINGFROM LEPROSY:A PERSPECTIVE ONIMMUNOLOGY AND THE THIRDWORLD BARRY R. BLOOM From the Departmentsof Microbiology and Immunology. andCell Biology, Albert Einstein Collegeof Medicine. Bronx,NY 10461 "If we take the widest and wisest view of a Cause. there is no such thingas a Lost Cause, because there is no such thingas a Gained Cause. We fight for Lost Causes because we know that our defeat and dismay may be the preface to our successors' victory, although that victory itself will be temporary; we fi ht rather to keep somethning alive than in the expectation t fl at anything will triumph. "T.S. Eliot "A Map of the World Without Utopia on It Is not Worth Glancing At." "Oscar Wilde Let mebegin with a case history. notof an individual. tussis,tetanus, tuberculosis, polio, and measles, and but ratherof a country. any of the fortypoorest nations consequently 0.5%of them became lame from polio, 1% on earth. Let me ask you to try to imagine our qualityof died from neonatal tetanus. 2% succumbedto whooping life, if life expectancy at birth in this countrywere 42 yr. cough. and 3%died from measles. We would be living in if infant mortality at birth were 140 per thousand.if 40% a country whose average gross national product per cap- of our children suffered from malnutrition. and if only ita would be $310/yr: in which 37% of males, but only 10%of children were immunized against diphtheria, per-14% of females, would be literate.