Multidrug resistance and ESBL-producing Salmonella spp. isolated from broiler processing plants

ht t p : / / w w w . b j m i c r o b i o l . c o m . b r /

Food

Microbiology

Multidrug

resistance

and

ESBL-producing

Salmonella

spp.

isolated

from

broiler

processing

plants

Rosangela

Estel

Ziech

_,

_Camila

_Lampugnani

_,

_Ana

_Paula

_Perin

_,

Mallu

Jagnow

Sereno

_,

_Ricardo

_Antônio

_Pilegi

_Sfaciotte

_,

_Cibeli

_Viana

_,

Vanessa

Mendonc¸a

Soares

_,

_José

_Paes

_de

_Almeida

_Nogueira

_Pinto

_,

Luciano

dos

Santos

Bersot

a_{ProgramadePós-Graduac¸ãoemCiênciaAnimal,UniversidadeFederaldoParaná(UFPR),RuaPioneiron}◦_{2153,BairroJardimDallas,}

Palotina,PR85950-000,Brazil

b_{UniversidadeFederaldoParaná(UFPR),RuaPioneiron}◦_{2153,BairroJardimDallas,Palotina,PR85950-000,Brazil}

c_{UniversidadeEstadualPaulistaJúliodeMesquitaFilho(UNESP),FaculdadedeMedicinaVeterináriaeZootecniadeBotucatu,}

DistritodeRubiãoJúniors/n,BotucatuSP18618-000,Brazil

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Articlehistory:

Received16December2014 Accepted24July2015

AssociateEditor:EduardoCesar Tondo

Keywords:

Antimicrobialresistance Salmonellaspp.

Foodbornepathogens

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Theaimofthisstudywastoinvestigatetheoccurrenceofmultidrug-resistant,extended spectrumbeta-lactamase(ESBL)producingSalmonellaspp.isolatedfromconveyorbeltsof broilercuttingroomsinBrazilianbroilerprocessingplants.Ninety-eightstrainsofSalmonella spp.wereanalyzed.Multidrugresistancewasdeterminedbythediskdiffusiontestand the susceptibilityoftheisolated bacteriawasevaluatedagainst18 antimicrobialsfrom sevendifferentclasses.ThedoublediskdiffusiontestwasusedtoevaluateESBL produc-tion.Ofthe98strainstested,84weremultidrugresistant.Thehighestratesofresistance wereagainstnalidixicacid(95%),tetracycline(91%),andthebeta-lactams:ampicillinand cefachlor(45%),followedbystreptomycinandgentamicinwith19%and15%ofstrain resis-tance,respectively.Bycontrast,97%ofthestrainsweresensitivetochloramphenicol.45% ofthestrainswerepositiveforthepresenceofESBLactivity.Inthisstudy,highratesof multidrugresistanceandESBLproductionwereobservedinSalmonellaspp.

©2015SociedadeBrasileiradeMicrobiologia.PublishedbyElsevierEditoraLtda.Thisis anopenaccessarticleundertheCCBY-NC-NDlicense

(http://creativecommons.org/licenses/by-nc-nd/4.0/).

∗ _{Correspondingauthor.}

E-mail:[email protected](R.E.Ziech).

http://dx.doi.org/10.1016/j.bjm.2015.11.021

1517-8382/©2015SociedadeBrasileiradeMicrobiologia.PublishedbyElsevierEditoraLtda.ThisisanopenaccessarticleundertheCC BY-NC-NDlicense(http://creativecommons.org/licenses/by-nc-nd/4.0/).

Introduction

Salmonellaspp.isoneofthemainagentsresponsiblefor sev-eralinfections,e.g.,foodbornegastroenteritis.Mostofthese infections cause self-limiting diarrhea and do not require antimicrobialtreatment.However,incertaincases,suchas when thebacterium is spread via blood stream leading to complicationssuchasmeningitis,antibiotictherapyis nec-essary.Suchcomplicationsaremostcommonlyobservedin childrenandelderlyandimmunecompromisedpatients. Flu-oroquinolonesandcephalosporinsarethedrugsoffirst-choice insuchcases.1

Food ofanimal origin, especially poultryderived items, arethe mainsourcesofinfectionbySalmonellaspp.2 _Given theimportancetoSalmonellaspp.ascausativeagentsinfood bornediseases,reductionofitscontaminationonbroiler car-cassesisofextremelyhigh priority forindustry aswell as regulatoryagencies.3_{TheoccurrenceofSalmonellaspp.onthe} broilercarcassesmight bearesultofcontaminationeither at the farm or cross-contamination within the processing plant.4_{Cross-contaminationcanbeattributedpartlyto} resid-ual bacteria remaining on surfaces and equipment after sanitization.5

Studies on Salmonella spp. are usually focused on ana-lyzing resistance of the bacterium to antimicrobials such as fluoroquinolones; but, in the last decade or so, bac-terial production of large spectrum beta-lactamases has alsobeen evaluated.6,7 _{In Enterobacteriaceae,resistance to} cephalosporins isgenerally attributedto the productionof largespectrumbeta-lactamasessuchasESBL(extended spec-trumbeta-lactamase)andAmpCbeta-lactamase.8_ESBListhe termused forany beta-lactamasethat isacquiredand not intrinsictoaspecies.Suchlactamasesquicklyhydrolyzeand confer resistanceagainst oxyimino-cephalosporins.Mutant beta-lactamasesthathavesimilaractivityarealsoreferredto asESBLs.9,10

ExtensivestudieshavebeenundertakentoanalyzeESBL productionbyKlebsiellaspp.,Enterobacterspp.,andEscherichia coli isolated from human clinical samples. These studies are prompted by the lack of therapeutic success against thesemicroorganisms,whichincludes,butnotrestrictedto, cephalosporins.Treatment isrenderedunsuccessful bythe acquisitionofresistancegenesthatresideonmobilegenetic elements. For example, plasmids that transmit resistance genesforcephalosporinsarefrequentlyfoundtocarry resis-tancetootherantibiotics,suchasfluoroquinolones.11_Some authorshavealsoreportedESBLsinmicroorganismsisolated fromfoodproducts.12–14_{AccordingtoBlancetal.(2006),these} findingsaremorerecentinthecaseofE.coliandSalmonella spp.ascomparedtoKlebsiellaspp.andEnterobacterspp.ESBL productionbySalmonellaspp.isolatedfromanimalshasalso beenreported15,16_{;although,thereportsonESBLfromanimal} originarelessfrequent.17,18

Due tothe public healthrisk ofcross-contamination, it is important to have sufficient information on the occur-renceofpathogens,e.g.,Salmonellaspp.,inthecuttingrooms forbroilerprocessingand slaughteringfacilities.Itis espe-ciallyimportanttohaveknowledgeofthebehaviorofthese strains against antimicrobials. Therefore, the objective of

this study was to determine the occurrence of multidrug resistant in ESBL-producing Salmonella spp. isolated from conveyor belts in the cutting rooms of broiler processing plants.

Materials

and

methods

IsolationandidentificationofSalmonellaspp.

Strains of Salmonella spp. were obtained from the cutting roomsoffourdifferentBrazilianbroilerprocessingand export-ingplantshavingaslaughteringcapacityinexcessof160,000 broilers/day.FortheisolationofSalmonellaspp.fromthe sur-faceoftheconveyorbelts,thesponges(NascoWhirl-PakTM), pre-moistenedwith10mLof0.1%salinepeptonewater,were utilizedona400cm2_{area.Salmonellaspp.detectionwas}

car-riedoutaccordingtotheFoodandDrugAdministration(FDA– USA)methodologyaspublishedintheBacteriological Analyt-icalManual.19_{Subsequenttothesetests,isolatesofSalmonella} spp.wereconfirmedbygenusidentificationusingpolymerase chain reaction (PCR) for the sifB gene as per the protocol describedbyAlmeidaetal.20

Antimicrobialsusceptibilitytest

The susceptibility to antimicrobials was determined using the agar diffusion test as per the documents M31-A321 and M100-S2322 _{of the Clinical and Laboratory Standards} Institute. Eighteen antimicrobial agents from seven dif-ferent classes were tested: (1) Beta-lactams, divided into 3 subclasses: (a) Penicillins: ampicillin (AMP; 10␮g), (b) Cephalosporins: cefachlor (CFC; 30␮g) and ceftiofur (CTF; 30␮g), and (c) Carbapenems: meropenem (MER;10␮g) and imipenem (IPM; 10␮g); (2) Aminoglycosides: streptomycin (EST; 10␮g), tobramycin (TOB; 10␮g), gentamycin (GEN; 10␮g), amikacin (AMI; 30␮g) and neomycin (NEO; 30␮g); (3)Quinolones:enrofloxacin(ENO;5␮g),nalidixicacid(NAL; 30␮g),andciprofloxacin(CIP;5␮g);(4)Sulfamethoxazoleand Trimethoprim:sulfamethoxazole/trimethoprim (SUT; 25␮g); (5)Tetracyclines:tetracycline(TET;30␮g);(6)Phenicols: chlor-amphenicol (CLO;30␮g) and florfenicol(FLF; 30␮g) and (7) Polymyxins:polymyxinB(POL,300UI).Strainswere consid-eredmultidrugresistantiftheywereresistanttoatleastthree classes ofantimicrobials(atleastoneantimicrobialofeach class).23 _{Thequalitycontroltest wasbasedon E.coliATCC} 25922.

ESBLproduction

ESBL productionwasanalyzedbythedoublediskdiffusion test.24_{Thecentraldiskwashavingamoxicillinplusclavulanic} acid(AMX/AC;20/10␮g).Fourotherdiskswereplacedwithin a20mmradiusofthefirstone:ceftazidime(CAZ;30␮g), cef-triaxone(CRO;30␮g),cefepime(CPM,30␮g)and aztreonam (ATM; 30␮g).25 _{Samples were considered positive for ESBL} whentheinhibitionzonearoundanycephalosporinincreased towardthecentraldiskwithAMX/AC,andwhentheinhibition zonearoundatleastoneofthecephalosporinswassmaller than19mm.26

Results

Outofthe98strainsevaluated(26,23,19,and30fromeachof thefourcuttingrooms,respectively),threeweresensitivetoall antimicrobialstested,fourwereresistanttooneclass,seven wereresistanttotwoclasses,and84(86%)wereconsidered multidrugresistant.

Fig.1showstheresistanceprofilesofthemultidrug resis-tant strainsarranged accordingto the roomof origin,and the corresponding percentage profiles in each room. ESBL activitywasdetectedin45%ofthestrains.Fromthestrains positiveforESBLproduction,themostfrequentresistance pro-filewasagainstbeta-lactams,quinolones,and tetracyclines (38/44);theESBL-negativestrainswereresistantto aminogly-cosides,quinolones,andtetracyclines(36/54).Theresultsfor Salmonellaspp.antimicrobialsusceptibilitytestarepresented inFig.2.

Thestrains,sensitivetoallantimicrobials(3/98),originated fromRoom3and represented16% (3/19)ofthe total num-berofstrainsisolatedfromthisroom.Thesamepercentage ofresistancewasobservedforonlyoneortwoantimicrobial classesand52%(10/19)strainsweremultidrugresistant. How-ever,inRooms1,2,and4,100%(26/26),87%(20/23),and93% (28/30),respectively,oftheSalmonellaspp.strainswere mul-tidrugresistant.ThehighestnumbersofESBL-positivestrain wereisolatedfromRoom4,correspondingto54%(24/44)of thepositivestrains.

Room 1 2 3 4 ESBL β -LA C AMI QU I

SUT TET POL No

6

Resistance profile*

Fig.1–ResistanceprofileofmultidrugresistantSalmonella

spp.strainsasperESBLanalysisandcuttingroomof origin.*B-LAC,B-lactams;AMI,aminoglycosides;QUI, quinolones;SUT,sulfamethoxazole/trimethoprim;TET, tetracyclines;POL,polymixin.

Discussion

Recently,incidenceofantimicrobialresistanceinSalmonella spp.isolatedfromfoodsofanimalorigin,especiallypoultry products, has increased.27–29 _{In this study, all strainswere} sensitivetociprofloxacinand95%ofthemwereresistantto nalidixicacid (Fig. 2).Hamidiamet al.30 _{suggestedthat the} lowinvitroresistancetociprofloxacinmaybeduetoa muta-tioninthegyrAgeneandthatinvitroresistancetonalidixic acid maybeusedtodetecttheactuallevelofresistanceto ciprofloxacin.TheCLSI22_{recommendsthatresistancetothis} classofantimicrobialsshouldbeconsideredascollective,that is,resistancetoonedrugimpliesthatthemicroorganismis resistanttothewholeclass.Thisinformationisofgreat impor-tancebecausefluoroquinolonesareconsideredasthedrugof firstchoiceforthetreatmentofinfectionscausedbySalmonella spp.inhuman.31

Highlevelsofresistancewerealsoobservedagainst tetra-cycline(Fig.2).WorldwideincidenceofresistanceinSalmonella spp. isolated from the poultry production chain is vari-able withpercentages rangingfrom 96.6% to 21.8%.32–34 _In Brazil, Oliveira et al.35 _{reported low resistance indexes in} Salmonella Enteritidis isolated from humans, poultry car-casses,poultry-relatedsamples,and fooditemsinvolvedin foodbornedisease outbreaksinthesouthernregionofthe country.

Additionally, 97% ofthe strainstested were sensitiveto chloramphenicol(Fig.2),whichisoneofthefirstdrugsused inveterinarymedicineandwhichhasbeenbannedfrom ani-malproductioninBrazilsince1998.36_{Theuseoftetracycline} asagrowthpromoterinpoultryproductionisalsoprohibited inBrazil.37

All strains were sensitive to the carbapenems tested; this isan importantfinding because carbapenemsare the drugs of first choice in the treatment of ESBL-producing microorganisms.38 _{ESBL production was detected in 45%} (44/98)ofthestrains. TheseESBL-positivestrainswerealso multidrug resistant. Clemente et al.17 _{analyzed 1120} iso-lates of Salmonella spp. from food items of animal origin and found onlyfive ESBL-producing strains. However,they usedamethodologythatwasdifferentfromthepresentone. Nogueira-Mirandaetal.10_{comparedsixmethodologiesforthe} detectionofESBLinEnterobacterspp.andconcludedthatthe double disk diffusion testshowed sensitivity of89.2% and specificityof100%forthisspecies.Duetotheabsenceofa standardmethodologyapprovedbyanyoftheinternational committeesfortheevaluationofSalmonellaspp.,ESBL produc-tionmayresultinunderestimationoftheoccurrenceofthis phenotype.Itisalsodifficulttocomparedifferentstudies.The phenotypicconfirmatorytestsarehighlysensitiveand spe-cificascomparedtothegenotypicconfirmatorytests.39_This study wasaimedtoscreenESBLproducing organisms. Fur-ther researchisrequiredforthe genotypiccharacterization ofESBL-producingSalmonellaspp.foundinbroilerprocessing plants.

Inconclusion,thepresentstudydemonstratedmultidrug resistancein86%andESBLactivityin45%oftheSalmonella spp.isolatedfromthestudiedbroilerprocessingplants.These resultsshouldbetakenasaprecautionarywarningforthe

AMP POL 0% FLF CLO TET SUT CIP NAL ENO NEO AMI GEN TOB EST IPM MER CTF CFC 100% 90% 80% 70% 60% 50% 40% 30% 20% 10%

Susceptible Intermediate Resistant

Fig.2–PercentagesrecordedfortheantimicrobialsusceptibilitytestofSalmonellaspp.strainsisolatedfromcuttingrooms ofbroilerprocessingplants.AMP,ampicillin;CFC,cephachlor;CTF,ceftiofur;MER,meropenem;IPM,imipenem;EST, streptomycin;TOB,tobramycin;GEN,gentamycin;AMI,amikacin;NEO,neomycin;ENO,enrofloxacin;NAL,nalidixicacid; CIP,ciprofloxacin;SUT,sulfamethoxazole/trimethoprim;TET,tetracycline;CLO,chloramphenicol;FLF,florfenicol;POL, polymyxinB.

spreadofmultidrugresistantSalmonellaspp.inbroiler pro-ductionindustry.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

Acknowledgment

WearegratefultoLaboratóriodeInspec¸ãoeControlede Qual-idadedeAlimentoseÁgua,UniversidadeFederaldoParaná (UFPR)forsubsidizingthepurchasematerialsforthisstudy.

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c

e

s

1. MiriagouV,TassiosPT,LegakisNJ,TzouvelekisLS.

Expanded-spectrumcephalosporinresistancein

non-typhoidSalmonella.IntJAntimicrobAgents.

2004;23:547–555.

2. GreigJD,RavelA.Analysisoffoodborneoutbreakdata

reportedinternationallyforsourceattribution.IntJFood

Microbiol.2009;130:77–87.

3. BerrangME,BaileyJS,AltekruseSF,etal.Prevalence,

serotype,andantimicrobialresistanceofSalmonellaon

broilercarcassespostpickandpostchillin20U.S.processing

plants.JFoodProt.2009;72:1610–1615.

4. RasschaertG,HoufK,GodardC,WildemauweC,

Pastuszczak-FrakM,DeZutterL.Contaminationofcarcasses

withSalmonelladuringpoultryslaughter.JFoodProt.

2008;71:146–152.

5.RasschaertG,HoufK,DeZutterL.Impactoftheslaughter

linecontaminationonthepresenceofSalmonellaonbroiler

carcasses.JApplMicrobiol.2007;103:333–341.

6.ThrelfallEJ.AntimicrobialdrugresistanceinSalmonella:

problemsandperspectivesinfood-andwater-borne

infections.FEMSMicrobiolRev.2002;26:141–148.

7.LiXZ,MehrotraM,GhimireS,AdewoyeL.Beta-lactam

resistanceandbeta-lactamasesinbacteriaofanimalorigin.

VetMicrobiol.2007;121:197–214.

8.deJongA,SmetA,LudwigC,etal.Antimicrobial

susceptibilityofSalmonellaisolatesfromhealthypigsand

chickens(2008–2011).VetMicrobiol.2014;171:298–306.

9.LivermoreDM.Defininganextended-spectrum

beta-lactamase.ClinMicrobiolInfect.2008;14(suppl1):3–10.

10.Nogueira-MirandaKS,PalmeiroJK,ConteD,etal.Detection

ofextended-spectrum␤-lactamaseinEnterobacterspp.–

evaluationofsixphenotypictests.MicrobDrugResist.

2012;18:66–70.

11.NogueiraKS,PaganiniMC,ConteA,etal.Emergenceof

extended-spectrum␤-lactamaseproducingEnterobacterspp.

inpatientswithbacteremiainatertiaryhospitalinsouthern

Brazil.EnfermInfeccMicrobiolClin.2014;32:87–92.

12.CohenStuartJ,vandenMunckhofT,VoetsG,ScharringaJ,

FluitA,HallMLV.ComparisonofESBLcontaminationin

organicandconventionalretailchickenmeat.IntJFood

Microbiol.2012;154:212–214.

13.RyuSH,LeeJH,ParkSH,etal.Antimicrobialresistance

profilesamongEscherichiacolistrainsisolatedfrom

commercialandcookedfoods.IntJFoodMicrobiol.

2012;159:263–266.

14.Ojer-UsozE,GonzálezD,VitasAI,etal.Prevalenceof

EnterobacteriaceaeinmeatproductssoldinNavarra,Spain.

MeatSci.2013;93:316–321.

15.ClementeL,CorreiaI,ThemudoP,NetoI,Canic¸aM,Bernardo

F.AntimicrobialsusceptibilityofSalmonellaentericaisolates

fromhealthybreederandbroilerflocksinPortugal.VetJ.

2014;200:276–281.

16.JiangHX,SongL,LiuJ,etal.Multipletransmissiblegenes

encodingfluoroquinoloneandthird-generation

cephalosporinresistanceco-locatedinnon-typhoidal

Salmonellaisolatedfromfood-producinganimalsinChina.

IntJAntimicrobAgents.2014;43:242–247.

17.ClementeL,ManageiroV,FerreiraE,etal.Occurrenceof

extended-spectrum␤-lactamasesamongisolatesof

Salmonellaentericasubsp.entericafromfood-producing

animalsandfoodproducts,inPortugal.IntJFoodMicrobiol.

2013;167:221–228.

18.EgervärnM,BörjessonS,ByforsS,etal.Escherichiacoliwith

extended-spectrumbeta-lactamasesortransferableAmpC

beta-lactamasesandSalmonellaonmeatimportedinto

Sweden.IntJFoodMicrobiol.2014;171:8–14.

19.AndrewsW,HammackT.Salmonella.In:Bacteriological

AnalyticalManual[s.l.].U.S.FoodandDrugAdministration; 2007.

20.deAlmeidaMV,SilvaAJr,NeroLA.Evaluationoftarget

sequencesforthepolymerasechainreaction-based

detectionofSalmonellainartificiallycontaminatedbeef.

FoodbornePathogDis.2014;11:111–118.

21.CLSI.PerformanceStandardsforAntimicrobialDiskandDilution

SusceptibilityTestsforBacteriaIsolatedfromAnimals.Aproved Standard.CLSIDocumentM31-A3.3rded.Wayne,PA:Clinical

andLaboratoryStandardsInstitute;2008.

22.CLSI.PerformanceStandardsforAntimicrobialSusceptibility

Testing.23rdInformationalSupplement.CLSIDocument M100-S23.Wayne,PA:ClinicalandLaboratoryStandards

Institute;2013.

23.NgoiST,ThongKL.Molecularcharacterizationshowed

limitedgeneticdiversityamongSalmonellaEnteritidisisolated

fromhumansandanimalsinMalaysia.DiagnMicrobiolInfect

Dis.2013;77:304–311.

24.PitoutJDD,ReisbigMD,VenterEC,ChurchDL,HansonND.

Modificationofthedouble-disktestfordetectionof

enterobacteriaceaeproducingextended-spectrumand

AmpC␤-lactamases.JClinMicrobiol.2003;41:3933–3935.

25.SousaMAJr,FerreiraEV,Conceic¸ãoGC.Betalactamasede

espectroestendido(ESBL):umimportantemecanismode

resistênciabacterianaesuadetecc¸ãonolaboratórioclínico.

NewsLab.2004;63:152–174.

26.EUCAST.EuropeanCommitteeonAntimicrobialSusceptibility

TestingGuidelinesforDetectionofResistanceMechanismsand SpecificResistancesofClinicaland/orEpidemiologicalImportance.

EuropeanSocietyofClinicalMicrobiologyandInfectious

Diseases:Sweden;2013.

27.AntunesP,RéuC,SousaJC,PeixeL,PestanaN.Incidenceof

Salmonellafrompoultryproductsandtheirsusceptibilityto

antimicrobialagents.IntJFoodMicrobiol.2003;82:97–103.

28.HurJ,KimJH,ParkJH,LeeYJ,LeeJH.Molecularandvirulence

characteristicsofmulti-drugresistantSalmonellaEnteritidis

strainsisolatedfrompoultry.VetJ.2011;189:

306–311.

29.BacciC,BoniE,AlpigianiI,LanzoniE,BonardiS,BrindaniF.

Phenotypicandgenotypicfeaturesofantibioticresistancein

Salmonellaentericaisolatedfromchickenmeatandchicken

andquailcarcasses.IntJFoodMicrobiol.2012;160:

16–23.

30.HamidianM,TajbakhshM,TohidpourA,RahbarM,ZaliMR,

Walther-RasmussenJ.DetectionofnovelgyrAmutationsin

nalidixicacid-resistantisolatesofSalmonellaentericafrom

patientswithdiarrhoea.IntJAntimicrobAgents.

2011;37:360–364.

31.PokharelBM,KoiralaJ,DahalRK,MishraSK,KhadgaPK,

TuladharNR.Multidrug-resistantandextended-spectrum

beta-lactamase(ESBL)-producingSalmonellaenterica

(serotypesTyphiandParatyphiA)frombloodisolatesin

Nepal:surveillanceofresistanceandasearchfornewer

alternatives.IntJInfectDis.2006;10:434–438.

32.ManieT,KhanS,BrözelVS,VeithWJ,GouwsPA.

Antimicrobialresistanceofbacteriaisolatedfrom

slaughteredandretailchickensinSouthAfrica.LettAppl

Microbiol.1998;26:253–258.

33.Carrami ˜nanaJJ,RotaC,AgustínI,HerreraA.Highprevalence

ofmultipleresistancetoantibioticsinSalmonellaserovars

isolatedfromapoultryslaughterhouseinSpain.Vet

Microbiol.2004;104:133–139.

34.ThaiTH,HiraiT,LanNT,YamaguchiR.Antibioticresistance

profilesofSalmonellaserovarsisolatedfromretailporkand

chickenmeatinNorthVietnam.IntJFoodMicrobiol.

2012;156:147–151.

35.DiasdeOliveiraS,SiqueiraFloresF,dosSantosLR,Brandelli

A.AntimicrobialresistanceinSalmonellaenteritidisstrains

isolatedfrombroilercarcasses,food,humanand

poultry-relatedsamples.IntJFoodMicrobiol.2005;97:

297–305.

36.Brasil.Portarian.448,de10desetembrode1998.Dispõe sobreaproibic¸ãodefabricac¸ão,importac¸ão,comercializac¸ão eoempregodepreparac¸õesfarmacêuticasdeuso

veterinário,derac¸ões,edeaditivosalimentaresque especificaerevogaaportariaquemenciona.Ministérioda AgriculturaeAbastecimento,Brasília;1998.

37.Brasil.Portarian◦159,de23dejunhode1992.Dispõesobrea proibic¸ãodousodeclortetraciclina,oxitetraciclinae penicilinacomopromotoresdecrescimento.Ministérioda AgriculturaeAbastecimento,Brasília.

38.ZhanelGG,WiebeR,DilayL,etal.Comparativereviewofthe

carbapenems.Drugs.2007;67:1027–1052.

39.PatersonDL,BonomoRA.Extended-spectrum

beta-lactamases:aclinicalupdate.ClinMicrobiolRev.