40KarlWeiss,MD,MSc;andGlennS.Tillotson,MS,FCCP(CAP)(80%)120%CAP1β-12003CAPCAPCAP(β-32)CAPCAP()()41β-1131CAPCAP1CAPCAP(community-acquiredpneumonia);(singlevsdualantibiotictherapy)41(Dr.Weiss),Maisonneuve-RosemontHospital,UniversityofMontreal,Montreal,QC,Canada;andOscientPharmaceuticals,Waltham,MA(Mr.Tillotson).Correspondenceto:KarlWeiss,MD,MSc,DepartmentofMicrobiologyandInfectiousDiseases,Maisonneuve-RosemontHospital,5415L'Assomption,Montreal,QC,CanadaH1T2M4;e-mail:weisscan@aol.com(community-acquiredpneumonia,CAP)CAP(80%)20%[1]Marrie[2]CAP10%60%12CAP[3]2935330(11%)67%CAP2/3[4](HIV)(COPD)[5,6]CAP[1,7]CAPβ-32β-2[8][9]2mg/L[10~12]Austrian[5]17%CAPCAP(amoxicillin)[13](levofloxacin)[1,7](efflux-mediated)[14]42[15][(moxifloxacin)(gemi-floxacin)]0.5%[16]Scheld[17][15,17~19]CAP72h72h2(NationalCommitteeforClinicalLaboratoryStandards)()()CAP[20]CAP,[5,6][21,22][23]()(COPD)(HIV)?(β-)CAPCAP[24]7(ICU)43[25~28]CAPCAP[29]4[25~28]CAP108CAP[30]24.1%CAP[31~32][32]8hGleason[31]30d111[(ciprofloxacin)]1β-CAP2(β-)-8-α[33]β-[34]A1964[5][35](cefotaxime)CAP1?Waterer[25]1(551)1β-1[27]44β-1409β-logistic(OR)0.4(95%0.17~0.92)[27][28](β-)(β-1)[26%(11/42)7.5%(4/53)P=0.02](113114)[36]()[10%(1/10)16.4%(14/85)]1β-[12,37]Moroney[37]ICU(Fine)[38][(gemifloxacin)trovafloxacin]92.5%87.3%Marrie[39][40]CAP1[(gatifloxacin)]CAPCAPCAPCAPFine4545[36]CURB-656[41]DNA45[42][43]1β-1131CAPCAPCAP[44]CAPCAP113131()1MandellLA,etal.ClinInfectDis2000;31,383−4212MarrieTJ.ClinInfectDis1994;18,501−5133BartlettJG,etal.NEnglJMed1995;333,1618−16244FineMJ,etal.JAMA1996;275,134−1415AustrianR,etal.AnnInternMed1964;60,759−7766TorresJM,etal.Chest1998;113,387−3907BartlettJG,etal.ClinInfectDis1998;26,811−8388JacobsMR,etal.JAntimicrobChemother2003;52,229−2469PallaresR,etal.IntJAntimicrobAgents2203;22,S15−S2410PallaresR.SeminRespirInfect1999;14,276−28411FeikinDR,etal.AmJPublicHealth2000;90,223−22912QuachC,etal.IntJAntimicrobAgents2002;20,113−11813BritishThoracicSociety.Thorax2001;56(Suppl),1−6414AmsdenGW.JAntimicrobChemother1999;4,1−615LonksJR,etal.ClinInfectDis2002;35,556−56416PowisJ,etal.AntimicrobAgentsChemother2004;48,3305−331117ScheldWM.EmergInfectDis2003;9,1−918DavidsonR,etal.NEnglJMed2002;346,747−75019WeissK,etal.ClinInfectDis2001;33,517−52220LodeH,etal.RespirMed2003;97,1134−114221FenollA,etal.JAntimicrobChemother2002;50(Suppl),13−1922WeissK,etal.JAntimicrobChemother2001;48,407−40923GillespieSH.IntJAntimicrobAgents2001;17,171−17624MandellLA,etal.ClinInfectDis2003;37,1405−143325WatererGW,etal.ArchInternMed2001;161,1837−184226MufsonMA,etal.AmJMed1999;107,34S−43S27MartinezJA,etal.ClinInfectDis2003;36,389−39528WeissK,etal.CanRespirJ2004;11,589−59329LiebermanD,etal.Thorax1996;51,179−18430WatanakunakornC,etal.ArchInternMed1997;157,1965−197131GleasonPP,etal.ArchInternMed1999;159,2562−257232MeehanTP,etal.JAMA1997;278,2080−208433TakizawaH,etal.AmJRespirCritCareMed1997;156,266−27134KaulR,etal.ClinInfectDis1999;4,800−80735LinE,etal.AntimicrobAgentsChemother2003;47,1151−115336FineMJ,etal.NEnglJMed1997;336,243−25037MoroneyJF,etal.ClinInfectDis2001;33,797−80538FileTM,etal.JAntimicrobChemother2001;48,67−7439MarrieTJ,etal.JAMA2000;283(6),749−75540DresserLD,etal.Chest2001;119,1439−144841LimWS,etal.Thorax2003;58,377−38242ZhangY,etal.JClinMicrobiol1995;33,596−60143MurdochDR,etal.JClinMicrobiol2001;39,3495−349844LodeH,etal.ClinTher2002;24,1915−1936CHEST2005;128:940−946