《环境工程微生物学》课程教学资源（英文教材）Foundations In Microbiology，8Th Edition（Kathleen Park Talaro）Mcgraw Hill 2012（彩色版）.pdf_大学文库

AbouttheAuthorsKathleenPark Talaro is a microbiologist, educator,author,andartist.Shehasbeennurturingherloveofmicrobiology since heryouth growing up on an ldaho farm where shewas first fascinated by tiny creatures she could just barely seeswimming in a pond.This interest in themicrobial world led toabiologymajoratldahoStateUniversitywheresheworkedasa teaching assistant and scientific illustratorfor one of her pro-fessors.Thiswasthebeginningofanavocationwhichshecon-tinuestoday-thatoflendingherartistichandtointerpretationof scientific concepts.She continued her education at ArizonaStateUniversity,Occidental College,California InstituteofTechnology,and California StateUniversityShe has taught microbiology and major's biology courses atPasadena City College for 30 years, during which time she de-veloped new curricula and refined laboratory experiments. SheKathy Talaro (right) and her daughter, Nicole.has been an author of, and contributorto, several publicationsof the William C. Brown Company and McGraw-Hill Publisherssince the early 1980s, first illustrating and writing for laboratorymanuals and later developing this textbook. She has also servedDedicationas acoauthor with KellyCowan on thefirst two editions ofMicrobiology: A Systems Approach.We wishto dedicate this bookto microbes,thoseKathy continues to make microbiology a significant focusof her life and is passionate about conveying the significanceingenious beings that beckon us into another realmand practical knowledge of the subject to everyone, regardlessof theirprofessionor position.Inaddition to herwriting,shethat exists beyond our naked eyes.We marvel at theirkeeps current attending conferences and participating in theAmerican Societyfor Microbiology and its undergraduate edu-fantastic variety and wild,exotic ways of life.Andcational programs. She is gratified by the many supportiveevenaftermany lifetimesofstudy,westill havemuchnotes and letters she has received over the years from bookadoptersandstudentsto learnfromthetiny"animalcules"thatLeeuwenhoekShe lives inAltadena,California withhusbandDave Bedro-sian,and sonDavid.Whenevershecan, she spendstimewithfirst saw over 300 years ago in "such enormousher daughter Nicole, who lives in Wyoming.In her spare timeshe enjoys photography, reading true crime books, music,numbers that all the water seemed to be alive."crossword puzzles, and playing with her seven rescued kitties.iv

iv Kathleen Park Talaro is a microbiologist, educator, author, and artist. She has been nurturing her love of microbiology since her youth growing up on an Idaho farm where she was fi rst fascinated by tiny creatures she could just barely see swimming in a pond. This interest in the microbial world led to a biology major at Idaho State University, where she worked as a teaching assistant and scientifi c illustrator for one of her professors. This was the beginning of an avocation which she continues today—that of lending her artistic hand to interpretation of scientifi c concepts. She continued her education at Arizona State University, Occidental College, California Institute of Technology, and California State University. She has taught microbiology and major’s biology courses at Pasadena City College for 30 years, during which time she developed new curricula and refi ned laboratory experiments. She has been an author of, and contributor to, several publications of the William C. Brown Company and McGraw-Hill Publishers since the early 1980s, fi rst illustrating and writing for laboratory manuals and later developing this textbook. She has also served as a coauthor with Kelly Cowan on the fi rst two editions of Microbiology: A Systems Approach. Kathy continues to make microbiology a signifi cant focus of her life and is passionate about conveying the signifi cance and practical knowledge of the subject to everyone, regardless of their profession or position. In addition to her writing, she keeps current attending conferences and participating in the American Society for Microbiology and its undergraduate educational programs. She is gratifi ed by the many supportive notes and letters she has received over the years from book adopters and students. She lives in Altadena, California with husband Dave Bedrosian, and son David. Whenever she can, she spends time with her daughter Nicole, who lives in Wyoming. In her spare time she enjoys photography, reading true crime books, music, crossword puzzles, and playing with her seven rescued kitties. Dedication We wish to dedicate this book to microbes, those ingenious beings that beckon us into another realm that exists beyond our naked eyes. We marvel at their fantastic variety and wild, exotic ways of life. And even after many lifetimes of study, we still have much to learn from the tiny “animalcules” that Leeuwenhoek fi rst saw over 300 years ago in “such enormous numbers that all the water seemed to be alive.” About the Authors Kathy Talaro (right) and her daughter, Nicole. taL75292_fm_i-xxxii.indd Page iv 12/10/10 11:05 AM user-f469 /Volume/201/MHDQ245/taL75292_disk1of1/0073375292/taL75292_pagefiles /Volume/201/MHDQ245/taL75292_disk1of1/0073375292/taL75292_pagefile

About the AuthorsTheaddition of twoproven educators makes a great learning system even betterWriting a textbooktakes an enormous amount of timeBarry Chesshas been teach-and effort.Notextbook author has the time to write a greating microbiology at Pasadena Citytextbook and also write an entire book's worth of accompa-College for 14 years.He receivednying digital learningtools-at least not with any amountofhis Bachelor's and Master's de-success or accuracy. In the past, this material has often beengreesfromCalifornia StateUniver-builtafterthetextpublishes,buthopefully intimeforclassessity, Los Angeles, and did severalto start. With the new digital era upon us, it is time to beginyears of post-qraduate work at thethinking of digital tools differently.In classrooms across theUniversityof California, Irvine,country,thousands of students who are visual learners and-wherehis research focused on thebeennaveusingcomputersexpression of eukaryotic genes in-videogamessmariphonesvolved in the development of mus-music players, and a variety ofcle and bone.other gadgets since they couldAt Pasadena City College,Barry developed a new coursetalk are begging for an interac-in human genetics and helped to institute a biotechnologytive way to learn their courseprogram. He regularly teaches courses in microbiology,material.Enterthedigitalgeneral biology,and genetics, and works with students com-author. With this eighth edition,pleting independent research projects in biology and micro-weareexcitedtoaddprofessorbiology.Over the past several years, Barry's interests haveHeidi SmithfromFrontRangebequntofocusoninnovativemethodsofteachingthatleaoe.CommunityCollegetotheTalaro/to qreaterstudentunderstandingencasesforHCrItChess team. Heidi teaches microbiology and anatomy & physi-theNational CenterinScienceandforCaseStudyLeachingology and has worked hand-in-hand with the textbook authors,presented talks atnationalmeetinuse.ofcasestudcreating online tools that truly complement and enhance theiesintheclassroomh.Jn2009.hislaboratmanual,Labora-book's content.She ensured that all keytopics in the book havetoryApplicgtionsinMicrobiology:ACgseStudyApproach.wasinteractive, engaging activities spanning levels of Bloom's tax-published. He is thrilled andfortunatetobefeelsveronomy,andtiedtoLearningOutcomesinthebook.InstructorscollaboratingwithKathyTalaro,withwhom.hehas.workedcan now assign material based on what they cover in class, as-intheclassroomfor morethana decade,on thiseighthsess their students on theLearning Outcomes, and run reportsedition. Barry is a member of the American Society forindicating individual and/or class performance on a variety ofMicrobiology and regularly attends meetings in his fields ofdata.Because of Heidi,we can now offeryou a robust digitalinterest, both to keep current of changes in the disciplinelearning program,tied to Learning Outcomes,to enhanceyourand to exchange teaching and learning strategies with oth-lecture and lab, whether you run a traditional, hybrid, or fullyers in the field.online course."I am gratified to introduce Barry Chess, a professorat Pasadena City College,as my coauthor on this new edition.Hepromises to bring afresh eyeto thisprojectalong withhisownexpertise ingenetics and molecularbiology,and acommitmenttocraftingahighqualityproduct.Barryhasaneasy,veryreader-friendlywritingstylethatcomplementsmyown.Heisastute andknowledgeable, witha rare abilityto gettotheheart of complexprinciplesyetkeepthe readerinvolved and interestedalongtheway.Heoften incorporatesanecdotes,mnemonicdevices,casestudies,and analogiesforhelpingstudentstolearnandunderstandmoredifficultandabstractconcepts."KathleenParkTalaro

v Barry Chess has been teaching microbiology at Pasadena City College for 14 years. He received his Bachelor’s and Master’s degrees from California State University, Los Angeles, and did several years of post-graduate work at the University of California, Irvine, where his research focused on the expression of eukaryotic genes involved in the development of muscle and bone. At Pasadena City College, Barry developed a new course in human genetics and helped to institute a biotechnology program. He regularly teaches courses in microbiology, general biology, and genetics, and works with students completing independent research projects in biology and microbiology. Over the past several years, Barry’s interests have begun to focus on innovative methods of teaching that lead to greater student understanding. He has written cases for the National Center for Case Study Teaching in Science and presented talks at national meetings on the use of case studies in the classroom. In 2009, his laboratory manual, Laboratory Applications in Microbiology: A Case Study Approach, was published. He is thrilled and feels very fortunate to be collaborating with Kathy Talaro, with whom he has worked in the classroom for more than a decade, on this eighth edition. Barry is a member of the American Society for Microbiology and regularly attends meetings in his fields of interest, both to keep current of changes in the discipline and to exchange teaching and learning strategies with others in the field. Writing a textbook takes an enormous amount of time and effort. No textbook author has the time to write a great textbook and also write an entire book’s worth of accompanying digital learning tools—at least not with any amount of success or accuracy. In the past, this material has often been built after the text publishes, but hopefully in time for classes to start. With the new digital era upon us, it is time to begin thinking of digital tools differently. In classrooms across the country, thousands of students who are visual learners and have been using computers, video games, smart phones, music players, and a variety of other gadgets since they could talk are begging for an interactive way to learn their course material. Enter the digital author. With this eighth edition, we are excited to add professor Heidi Smith from Front Range Community College to the Talaro/ Chess team. Heidi teaches microbiology and anatomy & physiology and has worked hand-in-hand with the textbook authors, creating online tools that truly complement and enhance the book’s content. She ensured that all key topics in the book have interactive, engaging activities spanning levels of Bloom’s taxonomy, and tied to Learning Outcomes in the book. Instructors can now assign material based on what they cover in class, assess their students on the Learning Outcomes, and run reports indicating individual and/or class performance on a variety of data. Because of Heidi, we can now offer you a robust digital learning program, tied to Learning Outcomes, to enhance your lecture and lab, whether you run a traditional, hybrid, or fully online course. About the Authors The addition of two proven educators makes a great learning system even better “I am gratifi ed to introduce Barry Chess, a professor at Pasadena City College, as my coauthor on this new edition. He promises to bring a fresh eye to this project along with his own expertise in genetics and molecular biology, and a commitment to crafting a high quality product. Barry has an easy, very reader-friendly writing style that complements my own. He is astute and knowledgeable, with a rare ability to get to the heart of complex principles yet keep the reader involved and interested along the way. He often incorporates anecdotes, mnemonic devices, case studies, and analogies for helping students to learn and understand more diffi cult and abstract concepts.” —Kathleen Park Talaro taL75292_fm_i-xxxii.indd Page v 12/10/10 11:05 AM user-f469 /Volume/201/MHDQ245/taL75292_disk1of1/0073375292/taL75292_pagefiles /Volume/201/MHDQ245/taL75292_disk1of1/0073375292/taL75292_pagefile

TheProfileofanExpertlyCraftedLearningToolArt and organization of content make this bookuniqueCarefully crafting a textbook to be a truly useful learning tool forstudents takes time and dedication.Every line of text and everypiece of art in this book is scrutinized for instructional usefulness,placement, and pedagogy,and then reexamined with each revision.In this eighth edition, the authors have gone through the book pagebypage,with more depth than ever before,to make sure it maintainsits instructional quality:fantastic art program; relevant and currentmaterial; and engaging, user-friendly writing style. Since the firstedition,thegoals of this book have been to explain complex topicsclearly and vividly,and to present the material in a straightforwardway that students can understand.The eighth edition continues tomeet these goals with the most digitally integrated, up-to-date, andpedagogically important revision yet.(a)Like a great masterpiece hanging in a museum, Foundations inMicrobiology is not onlybeautiful,but also tells a story, composedofmanypieces.Agreat textbook must becarefully constructed toplace art where it makes the most sense in the flow of the narrative;createprocessfiguresthatbreakdowncomplexprocessesintotheirsimplest parts; provide explanations at the correct level for the stu-dent audience, and offer pedagogical tools that help all types oflearners.Manytextbookauthorswritethenarrativeof theirbookand call it a day.It is the rare author team indeed, who examineseach page and makes changes based on what will help the studentsthe most, so that when the pieces come together, the result is anexpertly crafted learning toola story of themicrobial world."Foundations inMicrobiologyisan excellenttextbook and getting betterall the time."Kathy Talaro introduces new art to a revision by carefully sketchingout-KristineSnow, FoxValleyTechnical Collegewhatsheenvisionsinprecisedetail,withaccompanyinginstructionstothe illustrator. The result is accurate, beautifully rendered art that helpsdifficult concepts cometo life.A unique feature of this text's format is the early survey of microbial groups and their taxonomy (chapters 4,5,6).By using generaland specific names for microbes from the very beginning studentsAnotherdifferentfeatureofthistextischapter17Proceduresfor Identifying Pathogens and Diagnosing Infections"It brings to-developaworkingbackgroundthateasesthemintothelaterchaptersgether in one place the current methods used to diagnose infectiousStudents have a far greater appreciation for later topics of nutrition,metabolism, genetics, and microbial control if they recognizethediseases.Thechapterstartswithcollectingsamplesfromthepatientand details thebiochemical.serological, and molecularmethodsmaincharacters--bacteria.viruses,andeukarvoticmicroorganisms-used to identify causative microbes.and already know significant facts about them

Carefully crafting a textbook to be a truly useful learning tool for students takes time and dedication. Every line of text and every piece of art in this book is scrutinized for instructional usefulness, placement, and pedagogy, and then reexamined with each revision. In this eighth edition, the authors have gone through the book page by page, with more depth than ever before, to make sure it maintains its instructional quality; fantastic art program; relevant and current material; and engaging, user-friendly writing style. Since the first edition, the goals of this book have been to explain complex topics clearly and vividly, and to present the material in a straightforward way that students can understand. The eighth edition continues to meet these goals with the most digitally integrated, up-to-date, and pedagogically important revision yet. Like a great masterpiece hanging in a museum, Foundations in Microbiology is not only beautiful, but also tells a story, composed of many pieces. A great textbook must be carefully constructed to place art where it makes the most sense in the flow of the narrative; create process figures that break down complex processes into their simplest parts; provide explanations at the correct level for the student audience, and offer pedagogical tools that help all types of learners. Many textbook authors write the narrative of their book and call it a day. It is the rare author team indeed, who examines each page and makes changes based on what will help the students the most, so that when the pieces come together, the result is an expertly crafted learning tool—a story of the microbial world. “Foundations in Microbiology is an excellent textbook and getting better all the time.” —Kristine Snow, Fox Valley Technical College A unique feature of this text’s format is the early survey of microbial groups and their taxonomy (chapters 4, 5, 6). By using general and specific names for microbes from the very beginning students develop a working background that eases them into the later chapters. Students have a far greater appreciation for later topics of nutrition, metabolism, genetics, and microbial control if they recognize the main characters—bacteria, viruses, and eukaryotic microorganisms— and already know significant facts about them. x The Profile of an Expertly Crafted Learning Tool Art and organization of content make this book unique Kathy Talaro introduces new art to a revision by carefully sketching out what she envisions in precise detail, with accompanying instructions to the illustrator. The result is accurate, beautifully rendered art that helps difficult concepts come to life. Process Figure 9.6 The Assembly line of DNA replication in a circular bacterial chromosome. (a) A bacterial chromosome showing the overall pattern of replication. There are two replication forks where new DNA is being synthesized. (b) An enlarged view of the left replication fork to show the details of replication. Okazaki fragment 3. The template for the lagging strand runs the opposite direction (3′ to 5′) and must be replicated backwards away from the replication fork so the DNA polymerase can add the nucleotides in the necessary 5′ to 3′ arrangement. 4. Before synthesis of the lagging strand can start, a primase first constructs a short RNA primer to direct the DNA polymerase III. Synthesis can proceed only in short sections and produces segments of RNA primer and new DNA called Okazaki fragments. 5. A second polymerase (DNA polymerase I) acts on the Okazaki fragments by removing the primers. 6. Open spaces in the lagging strand are filled in by a ligase that adds the correct nucleotides. 1. The chromosome to be replicated is continuously unwound by a helicase, forming a replication fork with two template strands. 2. The template for the leading strand (bottom) is correctly oriented for the DNA polymerase III to add nucleotides in the 5′ to 3′ direction towards the replication fork, so it can be synthesized as a continuous strand. Note that direction of synthesis refers to the order of the new strand (red). Template strand New strand RNA primer Helicase Key: Primase DNA polymerase III DNA polymerase I Ligase (b) (a) Replication forks 1 2 3 4 5 6 5′ 3′ 5′ 5′ 3′ 5′ 3′ 5′ 3′ 3′ Leading strand synthesis Lagging strand synthesis taL75292_ch09_254-290.indd Page 261 11/12/10 11:16 PM user-f494 /Volume/201/MHDQ245/taL75292_disk1of1/0073375292/taL75292_pagefiles Another different feature of this text is chapter 17, “Procedures for Identifying Pathogens and Diagnosing Infections.” It brings together in one place the current methods used to diagnose infectious diseases. The chapter starts with collecting samples from the patient and details the biochemical, serological, and molecular methods used to identify causative microbes. taL75292_fm_i-xxxii.indd Page x 12/21/10 6:13 PM user-f469 /Volume/201/MHDQ245/taL75292_disk1of1/0073375292/taL75292_pagefiles /Volume/201/MHDQ245/taL75292_disk1of1/0073375292/taL75292_pagefile

The Structureof anExpertlyCraftedLearning ToolChapter opening casefilesEach chapter opens with a Case File,which helps the students ap-preciate and understand how microbiology impacts their lives. Line3art, micrographs, and quotes have been added to the chapter-openingpage, where appropriate, to help the students pull together the bigpicture and grasp the relevance of the material they're about toToolsofthelearn.ThequestionsthatdirectlyfollowtheCaseFilechallengeLaboratorystudents to begin to think critically about what they are about toMerthods of Studyingread, expecting that they'll be able to answer them once they'veMicroorganismworked through the chapter.A new Continuing the Case featurenow appears within the chapter where relevant,to help students fol-low the real-world application of the case. The Case File Perspec-tive wrapsupthe case at the end of the chapter,pulling together theapplicable content and the chapter's topics.Nearly all Case FilesBattlirare new in the eighth edition, including hot microbiological topicsthat are making news headlines today.NEW!CONTINUINGCASEEBeginning with the first diagnoses in March 2009, the influenzaoutbreakexplodedintoapandemicin onlysixweeks.Casrapidly appeared in Canada, Central and South America, therEuropeandAsia,andeventually.morethan200countries.B"l love the case study intro toCDC estimates, from April to November 2009 in the UnitedSta010.000ewereSomiCethe chapter.Ifeel the studentsdeaths. Deaths were particularly high among young childrennen whosetreatment had beendelayed.Forand(nomatterwhatdiscipline/majortunately, the disease experienced by most people was milderthsal flu, anditceatOcations,Thecommon symptoms arefever,mCASEFILEPERSPECTIVEtheyarepursuing)benefitfromproblems with breathing and coughing thatThe source of the infection in the first case was most likely theinformationpresentedinareal-twoweeks.Themostseriouscomplicationisventilator that controlled the woman's breathing,Medical devicesodtohelosssceptibletogroupthatlife scenario.The information isvirus were people 60 years or older.are readily contaminated by patients and healthcare workers. Anycase acquired during a stay in a hospital is defined as a nosocomialWhat is a pandemic?infection. These infections are most problematic in very compro-more engaging and relevant than Why would some people be more resistanmised patients, but stringent disinfection procedures can greatlyreduucetheirincidenceThesecondcaseprobablycamefromthestraight lecture andoften leadsFora wrop-up, see the CoseFile Perspective on pagesoiled piece of shrapnel rather than thefield hospital.to great group discussions."To say that a microbe has resistance to a drug means that itnaturallypossesses.orhasacguiredageneticmechanismtoavoid the effects of the drug.Usually, its genome carries one or-TraceyM.Steeno,Northeastmore genes that can eliminate thedrug or prevent it fromactWisconsin Technical Collegeing on the cells of the microbe. This leaves themicrobe free togrow and infect even in the presence of that drug."I think the case study at the beginning of each chapter iswonderfulbecauseitintroducesthestudentstothereal lifescenarios they will be involved in when they go into the alliedhealth profession.So in a sense,these are'practice'studies."-CarrollW.Bottoms,CollinCountyCommunityCollegeXi

“I love the case study intro to the chapter. I feel the students (no matter what discipline/major they are pursuing) benefi t from information presented in a reallife scenario. The information is more engaging and relevant than straight lecture and often leads to great group discussions.” —Tracey M. Steeno, Northeast Wisconsin Technical College Chapter opening case files Each chapter opens with a Case File, which helps the students appreciate and understand how microbiology impacts their lives. Line art, micrographs, and quotes have been added to the chapter-opening page, where appropriate, to help the students pull together the big picture and grasp the relevance of the material they’re about to learn. The questions that directly follow the Case File challenge students to begin to think critically about what they are about to read, expecting that they’ll be able to answer them once they’ve worked through the chapter. A new Continuing the Case feature now appears within the chapter where relevant, to help students follow the real-world application of the case. The Case File Perspective wraps up the case at the end of the chapter, pulling together the applicable content and the chapter’s topics. Nearly all Case Files are new in the eighth edition, including hot microbiological topics that are making news headlines today. xi “I think the case study at the beginning of each chapter is wonderful because it introduces the students to the real life scenarios they will be involved in when they go into the allied health profession. So in a sense, these are ‘practice’ studies.” —Carroll W. Bottoms, Collin County Community College The Structure of an Expertly Crafted Learning Tool NEW! The meningococcus: A million of these tiny culprits could fi t on the head of a pin, yet they can knock out a healthy adult in a few hours. Tools of the Laboratory Methods of Studying Microorganisms C H A P T E R 3 revealed no sign of pneumonia, and a blood test indicated an elevated white blood cell count. To rule out a possible brain infection, a puncture of the spinal canal was performed. As it turned out, the cerebrospinal fl uid (CSF) the technician extracted appeared normal, microscopically and macroscopically. Within an hour, she began to drift in and out of consciousness and was extremely lethargic. At one point, the medical team could not fi nd a pulse and noticed dark brown spots developing on her legs. When her condition appeared to be deteriorating rapidly, she was immediately taken to the intensive care unit and placed on intravenous antibiotics. One of the emergency doctors was overheard saying, “Her medical situation was so critical that our intervention was truly a matter of life or death.” Because her symptoms pointed to a possible infection of the central nervous system, a second spinal puncture was performed. This time, the spinal fl uid looked cloudy. A Gram stain was performed right away, and cultures were started. What are signs and symptoms of disease? Give examples from the case that appear to be the most diagnostically signifi cant. Why is so much importance placed on the CSF and its appearance? To continue the case, go to page 74. One Saturday evening in 2007, a 50-year-old woman began to suffer fl ulike symptoms, with fever, aching joints, sore throat, and a headache. Feeling miserable but not terribly concerned, she took some ibuprofen and went to bed. By the following morning, she began to feel increasingly ill and was unstable on her feet, confused, and complaining of light-headedness. Realizing this was more than just the fl u, her husband rushed her immediately to the nearest emergency room. An initial examination showed that most of her vital signs were normal. Conditions that may provide some clues were: rapid pulse and respiration, an infl amed throat, and a stiff neck. A chest X ray CASE FILE 3 Battling a Brain Infection “A matter of life or death” taL75292_ch03_058-088.indd Page 58 11/3/10 6:02 PM user-f468 /Volume/201/MHDQ245/taL75292_disk1of1/0073375292/taL75292_pagefiles CONTINUING CASE FILE 6 Beginning with the fi rst diagnoses in March 2009, the infl uenza outbreak exploded into a pandemic in only six weeks. Cases rapidly appeared in Canada, Central and South America, then Europe and Asia, and eventually more than 200 countries. By CDC estimates, from April to November 2009 in the United States alone, there were 50 million cases and close to 10,000 deaths. Deaths were particularly high among young children and pregnant women whose treatment had been delayed. Fortunately, the disease experienced by most people was milder than the usual seasonal fl u, and it cleared up with few complications. The common symptoms are fever, muscle aches, and problems with breathing and coughing that subside in one or two weeks. The most serious complication is pneumonia. One group that seemed to be less susceptible to H1N1 infl uenza virus were people 60 years or older. ■ What is a pandemic? ■ Why would some people be more resistant to the virus? For a wrap-up, see the Case File Perspective on page 181. taL75292_ch06_158-184.indd Page 169 11/8/10 12:12 PM user-f469 /Volume/201/MHDQ245/taL75292_disk1of1/0073375292/taL75292_pagefiles CASE FILE 9 PERSPECTIVE The source of the infection in the fi rst case was most likely the ventilator that controlled the woman’s breathing. Medical devices are readily contaminated by patients and healthcare workers. Any case acquired during a stay in a hospital is defi ned as a nosocomial infection. These infections are most problematic in very compromised patients, but stringent disinfection procedures can greatly reduce their incidence. The second case probably came from the soiled piece of shrapnel rather than the fi eld hospital. To say that a microbe has resistance to a drug means that it naturally possesses or has acquired a genetic mechanism to avoid the effects of the drug. Usually, its genome carries one or more genes that can eliminate the drug or prevent it from acting on the cells of the microbe. This leaves the microbe free to grow and infect even in the presence of that drug. taL75292_ch09_254-290.indd Page 287 11/12/10 11:18 PM user-f494 /Volume/201/MHDQ245/taL75292_disk1of1/0073375292/taL75292_pagefiles taL75292_fm_i-xxxii.indd Page xi 12/10/10 11:05 AM user-f469 /Volume/201/MHDQ245/taL75292_disk1of1/0073375292/taL75292_pagefiles /Volume/201/MHDQ245/taL75292_disk1of1/0073375292/taL75292_pagefile