Microbiology for Nurses by V. Deepa Parvathi, R. Sumitha, S. Smitha.

Microbiology for Nurses by V. Deepa Parvathi, R. Sumitha, S. Smitha. Microbiology for Nurses V.Deepa Parvathi Department of Human Genetics College of Biomedical Sciences, Technology and Research Sri Ramachandra University Porur, Chennai Tamil Nadu R. Sumitha Department of Biomedical Sciences College of Biomedical Sciences, Technology and Research Sri Ramachandra University Porur, Chennai Tamil Nadu S. Smitha C M Manguli Degree College Sindagi, Bijapur Karnataka Chennai • Delhi No part of this eBook may be used or reproduced in any manner whatsoever without the publisher’s prior written consent. Copyright © 2014 Dorling Kindersley (India) Pvt. Ltd. This eBook may or may not include all assets that were part of the print version. The publisher reserves the right to remove any material in this eBook at any time. ISBN 978-93-325-2527-6 eISBN 978-93-325-4066-8 First Impression Head Office: 7th Floor, Knowledge Boulevard, A-8(A) Sector 62, Noida 201 309, India. Registered Office:11 Community Centre, Panchsheel Park, New Delhi 110 017, India. Dedicated to our beloved Parents and Friends Foreword xxi Preface xxiii UNIT 1: INTRODUCTION 1 1Importance and Relevance of Microbiology to Nursing 3 2Role of a Nurse in Microbiology 4 3Historical Perspective 6 UNIT 2: GENERAL CHARACTERISTICS OF MICROBES 11 4Structure and Classification of Microbes 13 5Morphology—Size and Forms 28 6Flagella and Motility—Hanging Drop Technique 46 7Colonization, Nutrition, and Growth of Microbes 51 8Culture Media 72 9Laboratory Methods for the Identification of Microorganisms 82 10Staining Techniques 97 UNIT 3: INFECTION CONTROL 111 11Sources, Portals, and Transmission of Infections 113 12Asepsis, Disinfection, and Sterilization—Types and Methods 119 13Chemotherapy and Antibiotics 137 14Standard Safety Measures and Biomedical Waste Management 152 15Hospital Acquired Infection and Hospital Infection Control Programme 163 UNIT 4: PATHOGENIC ORGANISMS 175 16Bacteria 177 17Viruses 231 18Fungi 258 19Parasites 275 20Rodents and Vectors 285 UNIT 5: IMMUNOLOGY 295 21Immunity—Classification 297 22Antigen and Antibody Reaction 304 23Hypersensitivity Reaction 311 24Serological Tests 322 25Immunoprophylaxis 326 Glossary 333 Illustrations 341 Index 373 Foreword Preface xxi xxiii UNIT 1: INTRODUCTION 1 1 Importance and Relevance of Microbiology to Nursing 3 2 Role of a Nurse in Microbiology 4 3 Historical Perspective 6 3.1 Immunity and Vaccination 8 Multiple Choice Questions 9 Short Notes 10 Essay 10 UNIT 2: GENERAL CHARACTERISTICS OF MICROBES 11 4Structure and Classification of Microbes 13 4.1Introduction 13 4.1.1Overview of Prokaryotic Cell Structure 14 4.1.2Overview of Eukaryotic Cell Structure 14 4.2Structure of Prokaryotic Cell 14 4.2.1Intracellular Structures 14 4.2.2Extracellular Structures 15 4.3Shapes of Microbes 16 4.3.1Advantages of Shape to the Cell 16 4.4Structures Involved in Attachment 16 4.5Classification of Microbes 17 4.5.1Scientific Nomenclature (Binomial Nomenclature) 17 4.5.2Taxonomic Hierarchy of Escherichia coli 17 4.5.3Two-Kingdom Classification 18 4.5.4Three-Kingdom System 18 4.5.5Four-Kingdom System 18 4.5.6Five-Kingdom System 18 4.5.7Carl Woese’s Three-Domain System 20 4.6Universal Tree of Life 22 4.7Morphological Classification 23 4.8Nutritional Classification 23 4.9Biochemical Classification 24 4.10Classification Based on Staining Reaction 24 4.11Serological or Antigenic Classification 24 Multiple Choice Questions 24 Short Notes 26 Essays 27 5 Morphology—Size and Forms 28 5.1 Introduction 28 5.2 Bacterial Morphology 28 5.2.1 Size of Bacterial Cells 28 5.2.2 Shape of Bacterial Cells 29 5.2.3 Colony Morphology 30 5.3 Microscopy 31 5.3.1 Types of Microscopes 31 5.4 Anatomy of Bacteria 34 5.4.1 Architecture of a Bacterial Cell 35 5.4.2 Cell Wall-Deficient Bacteria 43 Multiple Choice Questions 43 Short Notes 44 Essays 45 6 Flagella and Motility—Hanging Drop Technique 46 6.1 Bacterial Motility 46 6.1.1 Types of Bacterial Motility 46 6.2 Detection of Bacterial Motility 48 6.2.1 Flagellar Staining 48 6.2.2 Motility Test 48 6.2.3 Direct Microscopic Examination 48 6.3 Importance of Bacterial Motility 49 6.3.1 Chemotactic Behaviour 49 6.3.2 Root Colonization 49 6.3.3 Pathogenesis 49 6.3.4 Twitching Motility 49 Multiple Choice Questions 49 Short Notes 50 Essays 50 7 Colonization, Nutrition, and Growth of Microbes 51 7.1 Colonization of Bacteria 51 7.1.1 Invasiveness 51 7.1.2 Toxigenesis 51 7.1.3 Adherence of Bacteria 52 7.1.4 Pathogenicity 52 7.1.5 Wound Colonization 52 7.2 Microbial Nutrition 53 7.2.1 Autotrophic Bacteria 53 7.2.2 Heterotrophic Bacteria 54 7.2.3 Symbiotic Bacteria 54 7.2.4 Parasitic Bacteria 54 7.2.5 Major Elements 55 7.3 Microbial Growth 56 7.3.1 Growth Factors 57 7.3.2 Uptake of Nutrients by Bacteria 57 7.3.3 Growth Curve 60 7.3.4 Continuous Culture 62 7.3.5 Synchronous Growth 63 7.4 Influence of Environmental Factors on Microbial Growth 64 7.4.1 Water Acidity and Solutes 64 7.4.2 Temperature 65 7.4.3 Oxygen Requirement 67 7.4.4 pH 68 7.4.5 Pressure 68 7.4.6 Radiation 68 Multiple Choice Questions 69 Short Notes 71 Essays 71 8Culture Media 72 8.1Introduction 72 8.2History of Culture Media 72 8.3Importance of Culture Media 73 8.4Common Components Used in Culture Media 73 8.4.1 Agar 73 8.4.2 Peptones 73 8.4.3 Water 73 8.4.4 Extracts 74 8.4.5 Body Fluids 74 8.5Classification of Culture Media 74 8.5.1Classification Based on Consistency 75 8.5.2Classification Based on Nutritional Components 76 8.5.3Classification Based on Functional Use 76 8.6Preparation and Storage of Culture Media 79 Multiple Choice Questions 80 Short Notes 81 Essays 81 9Laboratory Methods for the Identification of Microorganisms 82 9.1Good Laboratory Practices (GLP) 82 9.2Five I’s in a Microbiology Laboratory 83 9.2.1Inoculation 83 9.2.2Incubation 83 9.2.3Isolation 83 9.2.4Inspection 86 9.2.5Identification 86 9.3Molecular Techniques and Typing 86 9.3.1Species Identification 86 9.3.2Typing 87 9.3.3Genotyping 88 9.4Biochemical Identification Techniques 89 9.4.1Biochemical Tests 89 Multiple Choice Questions 95 Short Notes 95 Essays 96 10Staining Techniques 97 10.1Definition and Protocol 97 10.1.1Uses of Stains 98 10.1.2Some Commonly Used Stains 98 10.1.3Staining Bacteria 100 10.2Simple Staining 100 10.2.1Staining of Bacteria fromthe Colony 100 10.2.2Staining of Bacteria fromthe Broth 100 10.3Differential Staining 101 10.3.1Gram Staining 101 10.3.2Acid-Fast Staining 103 10.3.3Endospore Staining 104 10.3.4Capsule Staining 105 10.3.5Metachromatic Granule Staining (Albert’s Staining) 106 10.3.6Flagella Staining 106 10.3.7Calcofluor White Staining 107 Multiple Choice Questions 107 Short Notes 109 Essays 109 UNIT 3: INFECTION CONTROL 111 11Sources, Portals, and Transmission of Infections 113 11.1Introduction 113 11.2Classification of Infections 113 11.3Sources of Infections 114 11.3.1 Humans 114 11.3.2 Animals 114 11.3.3 Insects 115 11.3.4 Soil and Water 115 11.3.5 Food 115 11.4Portals of Entry and Exit 115 11.5Modes of Transmission of Infections 116 Multiple Choice Questions 117 Short Notes 118 Essays 118 12Asepsis, Disinfection, and Sterilization—Types and Methods 119 12.1Introduction 119 12.2Asepsis 119 12.2.1Practice of Aseptic Techniques 120 12.3Sterilization and Disinfection 120 12.4Types of Sterilization 120 12.4.1Physical Sterilization 121 12.5Types of Disinfection 131 Conclusion 134 Multiple Choice Questions 134 Short Notes 136 Essays 136 13 Chemotherapy and Antibiotics 137 13.1 Introduction 137 13.2 History of Antibiotics 138 13.3 General Properties of an Ideal Antibiotic 138 13.4 Classification of Antibiotics 139 13.4.1 Based on Target Organism 139 13.4.2 Based on Spectrum of Action 140 13.4.3 Based on Cidal and Static Activity 140 13.4.4 Based on Origin 140 13.4.5 Based on Mode of Action 141 13.5 Antifungal Drugs 145 13.6 Antiviral Drugs 146 13.7 Antiprotozoal Drugs 147 13.8 Antibiotic Resistance 149 Multiple Choice Questions 150 Short Notes 151 Essays 151 14 Standard Safety Measures and Biomedical Waste Management 152 14.1 Biomedical Waste Management 152 14.1.1 Collection and Segregation of Wastes 153 14.1.2 Containment and Labelling 154 14.1.3 Transportation 155 14.1.4 Treatment of Biomedical Waste 155 14.1.5 Disposal 156 14.1.6 Record Maintenance 157 14.2 Risk Assessment 157 14.2.1 Pathogenicity 157 14.2.2 Route of Transmission 157 14.2.3 Infectious Agent Stability 157 14.2.4 Infectious Dose 157 14.2.5 Susceptibility of the Host 157 14.2.6 Concentration and Volume of the Pathogen 158 14.3 Standard Safety Measures 158 14.3.1 Containment 158 14.3.2 Personal Protective Equipment 158 14.3.3Biological Safety Cabinets 159 14.3.4Facility as a Barrier 159 14.3.5Biosafety Levels 160 Multiple Choice Questions 161 Short Notes 161 Essays 162 15 Hospital Acquired Infection and Hospital Infection Control Programme 163 15.1 Introduction 163 15.1.1 Occurrence of Infections 163 15.1.2 Microbial Causes 165 15.2 Epidemiology of Nosocomial Infections 165 15.2.1 Nosocomial Infection Sites 165 15.2.2 Urinary Tract Infections 165 15.2.3 Surgical Site Infections 166 15.2.4 Nosocomial Pneumonia 166 15.2.5 Nosocomial Bloodstream Infections 166 15.2.6 Skin and Soft Tissue Infections 167 15.2.7 Other Nosocomial Infections 167 15.3 Infection Control Programmes: Protocols 167 15.3.1 National Programmes 167 15.3.2 Hospital Programmes 168 15.3.3 Infection-Controlling Responsibility 168 15.4 Nosocomial Infection Surveillance 170 15.4.1 Objectives 170 Multiple Choice Questions 170 Short Notes 172 Essays 173 UNIT 4: PATHOGENIC ORGANISMS 175 16Bacteria 177 16.1Staphylococcus 177 16.1.1General Properties 177 16.1.2Cultural Characteristics 177 16.1.3Biochemical Properties 178 16.1.4Mode of Transmission 178 16.1.5Virulence Factor 178 16.1.6Pathogenesis 179 16.1.7 Laboratory Diagnosis 180 16.1.8 Prevention and Treatment 181 16.2 Streptococcus 182 16.2.1 Introduction 182 16.2.2 General Properties 182 16.2.3 Cultural Characteristics 182 16.2.4 Biochemical Properties 182 16.2.5 Mode of Transmission 182 16.2.6 Pathogenesis 183 16.2.7 Laboratory Diagnosis 183 16.2.8 Treatment 183 16.3 Neisseria 184 16.3.1 Introduction 184 16.3.2 Neisseria gonorrhoeae 184 16.3.3 Neisseria meningitidis 187 16.4 Corynebacterium 189 16.4.1 General Properties 189 16.4.2 Cultural Characteristics 189 16.4.3 Biochemical Properties 189 16.4.4 Mode of Transmission 189 16.4.5 Pathogenesis 189 16.4.6 Laboratory Diagnosis 190 16.4.7 Treatment 190 16.5 Enterobacteriaceae 191 16.5.1 Introduction 191 16.5.2 Escherichia 191 16.5.3 Klebsiella 194 16.5.4 Proteus 196 16.5.5 Shigella 198 16.5.6 Salmonella typhi 199 16.6 Mycobacterium 201 16.6.1 General Properties 201 16.6.2 Mycobacterium tuberculosis 201 16.6.3 Mycobacterium leprae 205 16.7 Vibrio cholerae 207 16.7.1 General Properties 207 16.7.2 Cultural Characteristics 208 16.7.3 Biochemical Properties 208 16.7.4 Mode of Transmission 208 16.7.5 Pathogenesis 208 16.7.6 Laboratory Diagnosis 209 16.7.7 Prophylaxis and Treatment 209 16.8 Spirochaetes 209 16.8.1 Introduction 209 16.8.2 Size and Structure 210 16.8.3 Habitat 211 16.9 Mycoplasma 211 16.9.1 Introduction 211 16.9.2 Morphology and General Characteristics 212 16.9.3 Cultural Characteristics 213 16.9.4 Biochemical Reactions 213 16.9.5 Susceptibility to Physical and Chemical Agents 213 16.9.6 Antigenic Properties 214 16.9.7 Pathogenicity 214 16.9.8 Laboratory Diagnosis 215 16.9.9 Treatment and Prophylaxis 215 16.10 Rickettsia 216 16.10.1 General Characteristics 216 16.10.2 Cultural Characteristics 216 16.10.3 Pathogenesis 216 16.10.4 Laboratory Diagnosis 217 16.10.5 Treatment 217 16.11 Chlamydia 217 16.11.1 Classification 217 16.11.2 General Characteristics 217 16.11.3 Developmental Cycle 218 16.11.4 Cultural Characteristics 219 16.11.5 Pathogenesis 219 16.11.6 Laboratory Diagnosis 220 16.11.7 Treatment 220 Multiple Choice Questions 221 Short Notes 227 Essays 229 17Viruses 231 17.1General Properties of Viruses 231 17.1.1Introduction 231 17.1.2Structure of Viruses 231 17.1.3Replication of Viruses 232 17.1.4Classification of Viruses 236 17.2 Herpesviridae 237 17.2.1 Morphology 237 17.2.2 Herpes Simplex Virus 238 17.2.3 Varicella Zoster Virus 239 17.2.4 Epstein–Barr Virus 240 17.2.5 Cytomegalovirus 241 17.3 Picornaviridae 242 17.3.1 Enteroviruses 242 17.3.2 Rhinoviruses 244 17.3.3 Hepatovirus (Hepatitis A Virus) 245 17.4 Rhabdoviridae 245 17.4.1 Rabies Virus 245 17.4.2 Host Range and Growth Characteristics 246 17.4.3 Pathogenesis 247 17.4.4 Clinical Features 247 17.4.5 Immune Response 247 17.4.6 Laboratory Diagnosis 247 17.4.7 Post-exposure Treatment and Prophylaxis 248 17.4.8 Rabies Vaccine 248 17.5 Retroviridae 249 17.5.1 Human Immunodeficiency Viruses 249 17.5.2 Laboratory Diagnosis 252 Multiple Choice Questions 253 Short Notes 256 Essays 257 18Fungi 258 18.1Introduction 258 18.2Morphological Classification 258 18.2.1Moulds 258 18.2.2Yeasts 259 18.2.3Dimorphic Fungi 260 18.3Taxonomical Classification 261 18.4Cell Wall of Fungi 262 18.5Fungal Reproduction 262 18.6Mycoses 263 18.6.1Superficial Mycosis 263 18.6.2Subcutaneous Mycosis 266 18.6.3Deep Mycosis 269 18.6.4Opportunistic Mycosis 270 Multiple Choice Questions 273 Short Notes 274 Essays 274 19 Parasites 275 19.1 Introduction 275 19.2 Entamoeba histolytica 275 19.2.1 Life Cycle 276 19.2.2 Pathogenesis 277 19.2.3 Laboratory Diagnosis 277 19.2.4 Treatment 277 19.3 Plasmodium sp. 278 19.3.1 Life Cycle 278 19.3.2 Pathogenesis 279 19.3.3 Laboratory Diagnosis 280 19.3.4 Treatment 280 19.4 Parasitic Helminths 280 19.4.1 Taenia solium 280 19.4.2 Wuchereria bancrofti 282 Multiple Choice Questions 283 Short Notes 284 Essays 284 20Rodents and Vectors 285 20.1Rodents 285 20.1.1Introduction 285 20.1.2Yersinia pestis 285 20.2Vectors 287 20.2.1Introduction 287 20.2.2Ticks 288 20.2.3Lice 290 20.2.4Mites 291 Multiple Choice Questions 292 Short Notes 293 Essays 293 UNIT 5: IMMUNOLOGY 295 21Immunity—Classification 297 21.1Introduction 297 21.1.1Recognition 297 21.1.2 Response 297 21.2 Types of Immunity 298 21.2.1 Innate Immunity 298 21.2.2 Adaptive Immunity 299 21.3 Cells of the Immune System 299 21.3.1 B Lymphocytes 300 21.3.2 T Lymphocytes 300 21.4 Humoral Immunity 301 21.5 Cell-Mediated Immunity 302 Multiple Choice Questions 302 Short Notes 303 Essay 303 22 Antigen and Antibody Reaction 304 22.1 Introduction 304 22.1.1 Antigens 304 22.1.2 Antibodies 304 22.2 Antigen–Antibody Interactions 305 22.3 Types of Antigen–Antibody Interactions 305 22.3.1 Precipitation Reactions 305 22.3.2 Agglutination Reactions 308 22.3.3 Enzyme-Linked Immunosorbent Assay 308 Multiple Choice Questions 309 Short Notes 310 Essays 310 23 Hypersensitivity Reaction 311 23.1 Introduction 311 23.1.1 Allergens 311 23.1.2 Inclination to Allergic Reaction 311 23.2 Classification of Hypersensitivity Reaction 312 23.2.1 Anaphylactic Hypersensitivity 312 23.2.2 Type II Hypersensitivity Reaction 316 23.2.3 Type III Hypersensitivity Reaction 317 23.2.4 Cell-Mediated Hypersensitivity 319 Multiple Choice Questions 321 Short Notes 321 Essay 321 24 Serological Tests 322 24.1 Introduction 322 24.2 Precipitation 322 24.3 Agglutination 323 24.3.1 Widal Test 323 24.3.2 Anti-Streptolysin OTest 324 Multiple Choice Questions 325 Short Notes 325 Essay 325 25 Immunoprophylaxis 326 25.1 Introduction 326 25.2 Active and Passive Immunity 326 25.3 Adjuvants 327 25.3.1 Functions of Adjuvants 327 25.4 Vaccines and Its Types 328 25.4.1 Live or Attenuated Vaccine 328 25.4.2 Killed Vaccines 328 25.4.3 Recombinant Subunit Vaccine 329 25.4.4 Conjugate Vaccine 329 25.4.5 Toxoid 330 25.5 Vaccination Schedule 330 25.6 Current Approaches in Vaccines 331 Multiple Choice Questions 331 Short Notes 332 Essay 332 Glossary 333 Illustrations 341 Index 373 As an academician who has taught biological sciences for forty years, few experiences are more gratifying than examining and evaluating scholarly write-ups of young authors. One such experience was when Deepa requested me to review her book Microbiology for Nurses jointly written with Ms R. Sumitha and Ms S. Smitha. This book is different from the many books already available on the subject in its radical approach to the topic and the innate charm of its script. It showcases the authors’ exemplary writing skills and subject knowledge with which they have, chapter by chapter, endeavored to present the elements of microbiology in a style that is comprehensible to students and health care professionals alike. The book will serve not only as a textbook for nursing students but also as a ready-reckoner to which they can turn to at any point in their career. Divided into five units for the learner’s convenience, the chapters of the book are succinctly illustra- tive and supported by a rich question bank. Unit 1 introduces microbiology from a historical perspective in three chapters; Unit 2 has seven chapters that illustrate the general characteristics of microbes; Unit 3 expounds on infection control in five chapters; Unit 4 focuses on pathogenic organisms in five chap- ters; Unit 5 is on immunology, which is covered in five chapters. A glossary of terms and acronyms used in the text has been added for the student’s benefit. The book also presents selected images in colored plates, explicit in their detail thanks to the characteristic meticulousness of Pearson Education. These plates enable the learner to appreciate the structural intricacies laid out in the illustrations. I strongly recommend Microbiology for Nurses by V. Deepa Parvathi, R. Sumitha and S. Smitha, not just for nursing students and the faculty who mentor them but for all health care professionals and students of medical microbiology, biotechnology and laboratory technicians. I am sure the approach the book has adopted as well as the method it espouses will help the reader to appreciate the relevance of microbiology to health care. I congratulate the authors for their magnificent and sustained effort to lay down the essentials of the subject in a manner that is forthright in its attempt to reach the reader with clarity. The concerted effort of the team at Pearson Education in bringing out this book is indeed laudable. SULTAN AHMED ISMAIL Former Head, Department of Biotechnology The New College, Chennai Director Ecoscience Research Foundation Chennai The science of microbiology has evolved and emerged as an important field in biomedicine and clinical practice. The emergence and re-emergence of various infectious agents, antimicrobial drug resistance and nosocomial infections have stirred remarkable advances in the understand- ing of concepts and hypotheses and kindled the development of various identification strategies and diagnostic tools. It is important for biologists to understand the fundamentals, analyze theoretical concepts and explore new avenues through observation and scientific enquiry. Microbiology for Nurses has been developed for students of nursing who study the subject as a part of their curriculum. It provides a simple, logical and comprehensive approach to learning the essentials of the subject. To this end, the objectives listed at the beginning of each chapter encapsulate the topics to be discussed and give the students an effective overview. An exhaus- tive glossary in simple sentences has been compiled to help students comprehend intricate biological terms and phrases. Every chapter concludes with pedagogical elements that consist of an array of multiple choice, short notes and essay questions designed to enable the students perform a progressive self-assessment of their understanding of the subject. The content of this book has been based on the curriculum framed by the Nursing Council of India and classified into five distinct units. It builds on the science of microbiology from its introductory concepts, probing first into the history and roles of nurses, and progressing gradu- ally to delineate the various methods used to classify and identify microorganisms. The book also expounds on the different techniques of sterilization, antibiotic therapy, biomedical waste management and nosocomial infections, which are of prime relevance in a clinical scenario. In addition, the book presents a detailed account of various pathogenic organisms and the role of immunology and vaccination in prophylaxis. It presents an assortment of diagrammatic illustra- tions, rendered conspicuous in color, to enhance clarity to the elucidations. The chapters have been conceptualized and written by three authors, each contributing topics in their respective areas of expertise and confidence in a student friendly and teacher recommendable manner. ACKNOWLEDGEMENTS This book is indeed the culmination of our combined effort and contributions in our respective areas of specialization and confidence. Our mutual encouragements, constructive criticisms and suggestions were vital in designing the table of contents and bringing about an overall depth xxiv | Preface to the discussions in the book. We take this opportunity to thank a few people without whose support and motivation, we could not have completed this book. We thank R. Dheepika, the acquisitions editor of the book, for her immense involve- ment and professionalism with which she followed up on the book’s progress. Her sugges- tions and inputs at every stage contributed to its overall development. We also commend C. Purushothaman and his team of the production department for their keen eye for detail in the proofs and for developing our hand-drawn images booking an impressive layout. We are obliged to Dr Gautham Annappa, Assistant Professor, Department of Studies & Research in Microbiology, Mangalore University, for his significant contributions to Unit 3. We appreciate the efforts of Ms S. Smitha, who rendered the book’s images as neat hand- drawn figures to accompany the manuscript. We are indebted to all our teachers for imparting in us the confidence and for all their words of happiness and encouragement. We are grateful to Sri. V. R. Venkataachalam, Chancellor of Sri. Ramachandra University, and the university’s management for their support and encouragement. We thank Dr Sultan Ismail for perusing the entire book and also for writing the foreword. We thank Ms Betty Lincoln, our dear friend, for all her prayers and words of strength. I express my gratitude to my dear father Mr A. Ravindran and my mother Dr Mallika Ravindran for being my pillars of strength. I am thankful to my husband Mr A. Madhu for his encouraging words and support. I am obliged to my children, M. Harini and M. Pragadesh, for their unconditional love. I specially thank Harini for helping us with a few hand-drawn images. I thank Dr T. S. Lokeswari, Head of the Department of Biomedical Sciences, for instilling in me the confidence with her words of motivation and appreciation. R. SUMITHA I am indebted to my beloved parents, Dr B. R. Shankar and Smt. Devibai, for their uncon- ditional love and support; and to my dear brothers, Chidanand and Gopal, for their help and encouragement. I specially thank my soul-mate and sister Bhagyalakshmi and my brother-in-law Mr Sagar for their endless motivation. I am indebted to my husband Dr K. Srinivas Naik for his undaunted support and help in all my endeavors. Most importantly, I thank my sons for their beautiful smiles which kept my energy levels from sinking while I was working on this book. S. SMITHA I thank the Almighty for showering his blessings on us and helping us to bring this project to fruition. I take this opportunity to thank my beloved parents, Mr V. Venkatachalam and Dr Raji Venkatachalam, and my brother Vishnu, for their unconditional love and support in all my academic and personal endeavors. Preface | xxv I am indebted to my dear husband Mr Koushik, and my parents-in-law, Dr Ramesh Rao and Mrs Padmini Ramesh, for their encouraging words and without whose support I could not have completed this project. My little son Ishaan is a source of happiness and energy in my life. He drives the best out of me by flashing his dimples! I am grateful to Ms V. Priyanka for her contribution towards the chapter on sources and portals of infection. My mentors, Dr Solomon FD Paul and Dr M. Ravi, have inculcated in me the art of scientific writing. I thank them for their support in all my professional accomplishments. V. DEEPA PARVATHI Unit 1 INTRODUCTION Microbiology is the study of microscopic organisms and involves the handling, identification, and manipulation of organisms of microscopic size (not visible to the naked eye). These organ- isms possess a simple anatomic structure with differentiation of cells and tissues. The microbial world includes prokaryotic and eukaryotic cells, which fundamentally differ from each other in the organization of the nucleus. In addition, the microbial world includes acellular obligatory parasites—viruses—as well. Microorganisms are diverse and play an important role in eco- system. They are also considered as one of the first living organisms to have evolved on earth. Many scientists across the globe have been working on the discovery of various microorgan- isms and the understanding of their implications on health, infections, and treatment modules. The important contributions of various scientists in the field of microbiology and the landmarks in microbiological research have been detailed in Chapter 3. Apart from understanding the role of microorganisms with respect to their modes of entry, routes of transmission, pathogenesis, and treatment in various infectious diseases, much has gone into the development of various aseptic culture techniques for the isolation and charac- terization of microorganisms. The concepts of asepsis, sterilization, and disinfection provide an understanding to the control of infectious diseases, especially in a hospital set-up. Care must also be taken with respect to sanitary conditions to control infections. Microbiology has utmost relevance in health care units, and it is important for health care professionals to understand the pathogenesis and control of infectious diseases. The mode of action of various antibiotics, the concept of antibiotic resistance, and multi-drug resistance are important apart from the methods of vaccination, types of vaccines, and schedules involved in vaccination. Understanding of the pathogenesis of virulent organisms, their epidemiology, host defense, and treatment strategies is an important aspect of medical microbiology. In addition, the role of the normal flora as opportunistic pathogens is critical. Health care professionals need to understand that microorganisms do not limit their role to infectious diseases alone. They play a vital role in the ecosystem, in the degradation of organic materials, recycling, and bioremediation. Microorganisms have been employed as model organisms in genetics and recombinant DNA technology to engineer agents for pest control, and they have also been widely used in the fermentation industry. In addition, many bacteria and viruses have also been used in gene therapy strategies and drug development. This chapter deals with the role of a nurse in relation to the condition of the patient, disease stage, diagnosis, treatment module, and hospital environment in a microbiological perspective. The role of a nurse is varied, and it is important for a nurse to multitask intellectually with fundamental knowledge, decisive thinking, and application. Nurses dedicate a lot of their time and energy on the patients. This chapter focuses on evolving nurses with a conceptual clinical approach towards the following: 1.Asepsis, sterilization, and disinfection 2.Recognition of infection 3.Infection control—pathogenesis and transmission 4.Nosocomial infection 5.Immune system 6.Clinical thought process It is important for nurses to learn the concepts and gain the knowledge and skills required to analyse and explore clinical situations. Their fundamental aim of providing quality patient care with professional ethics shall be strengthened if they think critically, plan strategies, and work with skill and effective communication. They need to understand the science of microbiology, from basic sciences to evidence-based nursing care. The theoretical learning process of nurses shall include understanding the biology of microbes from their fundamental evidence of discovery (including various historical contribu- tions of scientists across the globe and their experiments), their diversity in structure and patho- genesis, role of microbes in causing a disease, mechanisms involved in pathogenesis, routes of transmission, immune system of the host, infection control strategies adopted in hospitals, and various methods of asepsis and disinfection in terms of hospital equipment. The various tools and chemicals and their appropriate usage in asepsis, sterilization, and disinfection are of significance in patient care and hospital management. In addition, the different methods of sample collection, handling, storage, and transport of microbiological specimens and samples are considered vital in nursing education. Application towards the identification of microorgan- isms using laboratory tests (culture techniques and biochemical and serological tests) shall help a nurse read laboratory reports and understand the course of diagnosis and treatment strate- gies directed by the physician. Apart from this, it is important for nurses and other health care professionals (ward technicians, laboratory technicians, sanitary workers, etc.) to be educated adequately about self care and protective measures. Role of a Nurse in Microbiology | 5 It is important for nurses to learn the pathogenesis of microorganisms towards understanding the anatomy of bacteria; the presence of capsules, fimbriae, and virulence factors; and cell wall anatomy. Knowledge of physical and chemical methods of controlling microbial infections through radiation and various chemical agents is essential to control nosocomial infections. Nurses also need to be familiar with the compositions and routes of administration of various vaccines and antibiotics along with their preparations and formulation data sheets. Mechanisms of action of antibiotics and allergic reactions apart from antibiotic resistance have to be criti- cally understood. Moreover, knowledge of zoonoses, their reservoirs, and methods of transmis- sion is vital in medical microbiology. Understanding the host immune system in terms of types of immunities and various immune molecules such as interferons, cytokines, and complement proteins aids a nurse in deciphering the defence mechanism involved and generation of antibodies and establishment of immunity (active and passive). Apart from understanding clinical and medical microbiology, it is also an added advantage for nurses to realize the importance of microorganisms in food, agricul- ture, industries, and environment. Owing to the properties demonstrated and many advantages offered by microorganisms, they have been used as model organisms of research in genetics and recombinant DNA technology. The flow of information in the forthcoming chapters has been designed in such a way as to help nurses understand fundamental microbiology with critical thinking and application as well as perform their role effectively. Microbiology is the study of living organisms of microscopic size. The term microbiology was introduced by Louis Pasteur, who is referred to as the ‘father of microbiology’. Microbiology has various sub-disciplines of which medical microbiology deals with the aetiology of infec- tious diseases in human beings and animals, their pathogenesis, methods of diagnosis, treat- ment modules available, and preventive measures involved. Microorganisms of medical or clinical interest include bacteria, viruses, fungi, and proto- zoa. Most microorganisms can be observed with suitable magnification and staining techniques under light microscopes. The size of viruses, is generally less than 0.2 μm, and hence, they can- not be observed under conventional microscopes. Infections and diseases have been a major challenge to the society and the clinical community as they cause high morbidity and health risks worldwide. Many serious infectious diseases like AIDS have posed a major threat to the health of individuals. It is here that the applications of microbiology have contributed significantly to the practice of medicine in terms of diagnosis and prevention and providing better health care to the society as a whole. The science of microbiology has evolved greatly with the advancement of various molecular and biochemical tools coupled with automation to increase the efficiency and accuracy of diagnosis. The technology in vaccine development has seen tremendous growth in terms of developing vaccines against a plethora of infectious diseases, with high success rates in preventing and controlling epidemics as well. Microbiology has grown multifold because of simple observations and inventions made by early scientists. Anton van Leeuwenhoek, a Dutch lens maker, won the credit for devising a simple appa- ratus to aid the observation of microbial forms (e.g., shapes of bacteria—spherical, rod, and spiral). Though his effort was not initially recognized, two centuries later his contribution to the evolution of microscopy was acknowledged, and he is now referred to as the ‘father of bacteriology’. Louis Pasteur, in 1865, was consulted for the contamination of raw materials used for alcohol fermentation. His involvement in exploring the cause led him to focus on the role of microorganisms in the fermentation and spoilage of alcohol. Pasteur demonstrated that undesirable life forms could be destroyed by heating at 55°C–60°C for a short period of time. Subsequently, this process was modified and is now referred to as pasteurization. John Tyndall (1820–1893) demonstrated that prolonged heating was required for com- pletely eliminating life forms. He explained that bacteria existed in two forms: heat-stable and heat-sensitive. Prolonged or intermittent heating is required to destroy heat-stable forms. Tyndallization, is a process of intermittent heating which kills both forms. Joseph Lister (1827–1912) appreciated the emerging germ theory of disease. He advocated the use of carbolic acid as an aerosol during surgeries and impregnation of dressings to reduce the risk of post-operative infections. He established the fundamental principles of antisepsis for good surgical practice and hence is known as the ‘father of antiseptic surgery’. The science of microbiology evolved with the introduction of sterilization techniques by Pasteur and perfection of bacteriological techniques, staining procedures, and cultures by Robert Koch. The causative agents of various diseases were reported by different investigators. The disease-causing organisms discovered by various scientists along with the year of discov- ery are provided in Table 3.1. Table 3.1 Various Disease-causing Organisms Discovered by Scientists S.no. Scientist Organism Discovered Year 1 Robert Koch Bacillus of anthrax 1876 Bacillus of tuberculosis 1882 Vibrio cholerae 1883 2 Hansen Leprosy bacillus 1874 3 Neisser Gonococcus 1879 4 Alexander Ongston Staphylococci 1880 5 Eberth Typhoid bacillus 1880 6 Klebs and Loeffler Corynebacterium diphtheriae 1884 7 Rosenbach Staphylococcus 1886 8 Weichselbaum Meningococcus 1887 9 David Bruce Malta fever - Brucella 1887 10 Schaudinn and Hoffman Spirochaetes - Treponema pallidum 1905 The discovery of various microorganisms made it important to have a definite criterion to identify a microorganism as the causative agent of a disease. A microorganism is accepted as the causative agent of an infectious disease only if it follows Koch’s postulates, which are as follows: 1.The organism must be present in the lesions in every case of the infectious disease. 2.It should be possible to isolate the organism in pure culture from the lesions. 3.Inoculation of the pure culture into suitable laboratory animals should produce a similar disease. 4.It should be possible to re-isolate the organism in pure culture from the lesions pro- duced in experimental animals. 5.Specific antibodies to the organism should be demonstrable in the serum of the patient suffering from the disease. 3.1IMMUNITY AND VACCINATION Thucydides (464–404 BC), a Greek historian, observed during a plague epidemic in Athens that the sick and dying were able to recover because of the care provided by those who were already affected and knew that they would not contract the disease again. Immunization of healthy individuals with dried crusts of small pox was common in India and China. This would produce a mild form of small pox (variolation), and then the individual would recover and become resistant to the severe forms of the pox. Edward Jenner (1749–1823) tested the hypothesis that milkmaids who had been exposed to cowpox (vaccinia) from their herd never got infected with the dreaded small pox (variola) by inoculating them with the fluid from cow pox pustules. The vaccinated individuals reacted mildly and after recovery did not contract small pox when exposed to the virus. Louis Pasteur discovered that certain bacteria lost their virulence after extensive culturing in the laboratory, and he suggested that such bacteria might be capable of offering immunity. He demonstrated experiments with attenuated bacilli of anthrax on sheep, goat, and cow and challenged them with virulent forms of anthrax. He observed that all the vaccinated animals survived whereas the controls did not. Pasteur’s development of a vaccine against rabies was a significant breakthrough in vaccinations. He administered an attenuated suspension of rabies virus to Joseph Meister, a 13-year-old boy, who was bitten by a rabid dog, and saved him from the dreaded disease. The Pasteur Institute of Paris was built by public contribution during his lifetime for investigations on infectious diseases and preparation of vaccines. The important landmarks in the field of microbiology are highlighted in Table 3.2. Table 3.2 Important Landmarks in Microbiology 1676 Anton van Leewenhoek first described bacteria. 1765 Abbe Lazzaro Spallanzani conducted experiments to disprove the theory of spontaneous generation. 1796 Edward Jenner introduced the small pox vaccine. 1861 Louis Pasteur disproved the theory of spontaneous generation. 1863–1865 Pasteur devised pasteurization. 1865 Joseph Lister introduced antisepsis to treat wound infections. 1873 William Budd described the role of milk and water in the transmission of typhoid. (continued) Table 3.2 (continued) 1876 Robert Koch reported the isolation of pure culture of anthrax bacillus. 1880 Alphonse Laveran discovered the malarial parasite. 1881 Pasteur developed the anthrax vaccine. 1882 Robert Koch discovered Mycobacterium tuberculosis. 1884 Koch’s postulates were published. 1884 Metchnikoff announced the phagocytic theory of immunity. 1884 Hans Christian Gram introduced Gram staining. 1885 Louis Pasteur offered the first vaccination against rabies. 1888 Roux and Yersin discovered the diphtheria toxin. 1889 Brieger discovered the tetanus toxin. 1890 Kitasato and Von Behring discovered the tetanus antitoxin. 1890 Robert Koch discovered tuberculin. 1892 Ziehl and Neelsen developed acid fast staining. 1896 Paul Ehrlich introduced the methods of standardizing antitoxins and toxins. 1898 Paul Ehrlich expounded the side chain theory of immunity. 1900 Karl Landsteiner discovered blood groups. 1901 Bordet and Gengou described complement fixation. 1928 Alexander Fleming discovered penicillin. 1940 Karl Landsteiner and Wiener discovered the Rh factor. 1941 Albert Coons developed the fluorescent antibody test. 1943 Selman Waksman discovered streptomycin. 1948–1951 Three types of polio viruses were established. 1953 Jonas Salk and team devised the polio vaccine. 1954–1963 Jon Enders and Thomas Peebles developed the measles vaccine. 1956 Sabin developed the first oral polio vaccine. 1.The early microscope was invented by (a)Louis Pasteur (b)Anton van Leeuwenhoek (c)Robert Koch (d)Edward Jenner Ans. b 2. Tyndallization was named in honour of . (a)Robert Koch (b)Edward Jenner (c)Joseph Lister (d)John Tyndall Ans. d 3.Who is referred to as the father of antiseptic surgery? (a)Robert Koch (b) Edward Jenner (c) Joseph Lister (d) John Tyndall Ans. c 4.Koch’s postulates were proposed by . 7. Blood groups were discovered by . (a)Alexander Fleming (b)Paul Ehrlich (c)Karl Landsteiner (d)Ziehl and Neelsen Ans. c (a)Louis Pasteur (b)Anton van Leeuwenhoek (c)Robert Koch (d)Edward Jenner 5.Tuberculin was discovered by . (a)Louis Pasteur (b)Anton van Leeuwenhoek (c)Robert Koch (d)Edward Jenner 6.Penicillin was discovered by . (a)Alexander Fleming (b)Paul Ehrlich (c)Karl Landsteiner (d)Ziehl and Neelsen Ans. c Ans. c Ans. a 8. Research on pox vaccination was done by . (a)Edward Jenner (b)Louis Pasteur (c)Alexander Fleming (d)Paul Ehrlich Ans. a 9.Vaccination against rabies was offered by . (a)Edward Jenner (b)Louis Pasteur (c)Alexander Fleming (d)Paul Ehrlich Ans. b 10.Sabin and Salk are vaccines against . (a)Tuberculosis (b) Polio (c) Rabies (d) Cholera Ans. b SHORT NOTES 1.Mention 10 important landmarks in microbiological research. 2.What are Koch’s postulates? 3.Why is Louis Pasteur known as the father of microbiology? 4.What is the role of a nurse in microbiology? ESSAY 1. Give an overview of the history of microbiology. Add a note on the important landmarks and contributions of Louis Pasteur. Unit 2 GENERAL CHARACTERISTICS OF MICROBES 4.1Introduction 4.2Structure of Prokaryotic Cell 4.3Shapes of Microbes 4.4Structures Involved in Attachment 4.5Classification of Microbes 4.6Universal Tree of Life 4.7Morphological Classification 4.8Nutritional Classification 4.9Biochemical Classification 4.10Classification Based on Staining Reaction 4.11Serological or Antigenic Classification 4.1INTRODUCTION Microorganisms are those that scale to micro level in terms of measurement and dimen- sions. They are made up of one cell (unicellular) or a few cells (multicellular). They are diverse, exist abundantly on Earth, and can survive in the most extreme environmental conditions. Microorganisms can be divided into several categories based on their distinct characteristics. The studies on microorganisms focus on their beneficial effects and also their pathogenic impact. In addition, microbes play an important role in maintaining the ecological balance in ways of decomposing organic wastes, in agriculture, and in industries. The application of microbes in research is diverse and challenging. This chapter focuses primarily on the structure and classification of microbes in terms of their morphology and then proceeds towards varied classification methods. Cells are divided into two basic types, which are as follows: 1.Prokaryotic cells 2.Eukaryotic cells 4.1.1Overview of Prokaryotic Cell Structure (Figure 4.1) Prokaryotic cells are smaller when compared with eukaryotic cells. In these cells, the cytoplasm is enclosed by the cell membrane, and the cell organelles freely float, without any membrane, in this cytoplasm. Nucleus is called nucleoid as it lacks the membrane surrounding it; that is, it contains a naked DNA molecule. Blue green algae and bacteria are examples of prokaryotes. Flagella DNA Ribosome Cytoplasm Pili Cell Wall Capsule Cell Membrane Figure 4.1 Structure and Contents of a Typical Prokaryotic (Bacterial) Cell (See page 341 for the colour image) 4.1.2Overview of Eukaryotic Cell Structure Eukaryotic cells have a true nucleus, that is, the nucleus is membrane bound. The DNA is divided among many chromosomes and resides in the nucleolus. These cells are larger and are well defined with a central membrane-bound nucleus, and a variety of intracellular structures and membrane-bound organelles in the cytoplasm. This cytoplasm is surrounded by the cell membrane. In case of plants, a cell wall is present protecting the membrane that lies next to it. Protists, fungi, animals, and higher plants are examples of eukaryotes. 4.2STRUCTURE OF PROKARYOTIC CELL 4.2.1Intracellular Structures The bacterial cell is surrounded by the cell membrane, which is also called the plasma membrane. This membrane acts as a protecting shield for the cell; it encloses all the essential belongings of the cell within it. The cell comprises the cytoplasm, cell organelles, chromosome, essential nutrients, proteins, and other necessary components of cytoplasm. Generally, prokaryotes do not have membrane-bound organelles and a membrane-bound nucleus; rather, they have few intracellular structures. They do not have mitochondrion and chloroplasts. Bacterial hyperstruc- tures are nothing but the cytoskeletal structures seen in prokaryotes. Protein-bound bacterial organelles are called carboxysomes. Nucleoid, which is a single circular chromosome sus- pended in the cytoplasm in an irregular fashion, can be seen in prokaryotes. The chromosome is associated with protein and RNA. The ribosomes are different from that of Archaea and Eubacteria. Intracellular nutrient storage granules are constructed by the bacteria for storing essential nutrients, which can be used by the bacteria when needed. Glycogen, polyphosphate, sulphur, and polyhydroxyalkanoates are some of the storehouse materials of the cell. Some photosynthetic bacteria like Cyanobacteria synthesize internal gas vesicles. These gas vesicles help them to float by providing buoyancy to the cell. 4.2.2Extracellular Structures Cell Envelope In some bacteria, the cell wall can be seen lying just outside the cytoplasmic membrane. The cell wall is mainly made up of murein (also called peptidoglycan), which is a polysaccharide chain cross-linked by peptides containing D-amino acids. Cell wall content will differ with organism; for example, bacterial cell wall is made up of peptidoglycan, fungi cell wall of chitin, and plant cell wall of cellulose. Archaea differ from bacteria by lacking peptidoglycan in their cell wall. In bacteria, two different types of cell wall composition can be seen, one in Gram- positive bacteria and the other in Gram-negative bacteria (Figure 4.2). Gram Positive Gram Negative Peptidoglycan Periplasmic Space Plasma Membrane Cytoplasm Lipopolysaccharide [outer membrane] Periplasmic Space Peptidoglycan Plasma Membrane Cytoplasm Figure 4.2 Cell Wall Differences between Gram-Positive and Gram-Negative Bacteria (See page 341 for the colour image) Gram-positive bacteria possess a thick cell wall that contains many layers of peptidoglycan and teichoic acids. Gram-negative bacteria have a relatively thin cell wall that is made up of a few layers of peptidoglycan surrounded by a second lipid membrane containing lipopolysac- charides and lipoproteins. S Layer In many bacteria, an S layer covers the outside of the cell. This S layer is made up of a crystal- line protein. It provides chemical and physical shield for the cell surface and acts as a macromo- lecular diffusion barrier. The S layer has diverse effects but its functions are poorly understood. 4.3SHAPES OF MICROBES Microbes exhibit different shapes (Figure 4.3), and they are as follows: 1.Spherical: Cells that are spherical are called cocci. If the cell divides once in one axis, it produces diplococci. If it divides more than once to produce a chain, then it is called streptococci. If it divides regularly in two planes at right angles or at different angles to produce a cuboidal packet, then it is called staphylococci. 2.Rod: Cells that are cylindrical are called rods or bacilli. 3.Spiral: Cells that are coiled are called spiral or spirilla. Diplococci Staphylococci Bacillus [Rod] Coccus Spirillum Vibrio Streptococci Figure 4.3 Shapes of Microbes (See page 342 for the colour image) 4.3.1Advantages of Shape to the Cell Spirochaete 1.Cocci shape offers more resistance to drying when compared with bacilli. 2.Bacilli shape helps the intake of dilute nutrients into the cell from the environment as the surface area of rods is higher. 4.4STRUCTURES INVOLVED IN ATTACHMENT 1.Glycocalyx: Glycocalyx forms multicellular aggregates by binding the cells together. Few bacterial cells adhere to solid surfaces using this structure; for example, some aquatic bacteria adhere to rocks. Some bacteria are involved in plaque formation leading to dental caries. 2.Fimbriae: Possession of fimbriae is an inherited trait. Fimbriae arise from the cytoplasmic membrane or sometimes from just below the membrane. Fimbriae are not involved in motility. Fimbriae are numerous and shorter when compared with flagella. 3.Pili: Pili are similar to fimbriae but are fewer (sometimes only one per cell) and longer. There are three functional types of bacterial pili, which are as follows (a)Pili that act as receptor sites for attachment of some phages (b)Pili that act as sex pili for bacterial conjugation processes (c)Pili that help in the attachment of pathogenic bacteria to human tissues