Antibiotics and Antibiotic Resistance - PowerPoint Presentation

1. Antibiotics and Antibiotic Resistance

2. OutlineHistory of antibiotics and typesAntibiotic resistances and MSRA Methicillin-resistant Staphylococcus aureus Methodologies for detectionCase StudiesConclusions

3. Antibiotics Have Transformed Human Medicine

4. What is an Antibiotic?An antibiotic is a selective poisonIt has been chosen so that it will kill the desired bacteria, but not the cells in your body. Each different type of antibiotic affects different bacteria in different waysSubstances produced by various species of microorganisms: bacteria, fungi, actinomycetes - to suppress the growth of other microorganisms and to destroy them

5. Different modes of actionMode of ActionExamplesTypical UsesInhibit Bacterial Cell WallBiosynthesisb-lacatams, cephalosporins,glycopeptides, everninomycinsHuman therapeutic and animal therapeutic/ subtherapeuticBlock 30S or 50SRibosomes (inhibit protein synthesis)Macrolides, streptogramins,chloramphenicol, fusidic acid, tetracyclines, lincosamides, aminoglycosides, oxazolidinones, Human therapeutic and animal therapeutic/ subtherapeuticBlock Replication of DNAQuinolines, rifamycinesTreat urinary tract, systemic, and respiratory infectionsDisrupt Integrity of CellMembranesAntifungal azoles, polyenesTreat fungal infections, topicalapplication for EczemaAntagonize MetabolicProcessesSulfonamides, trimethoprim (TMP)Humans, livestock, aquaculture; TMP and sulfamethoxazole often prescribed together

6. The story begins…Penicillin – 1928Alexander Flemming found antimicrobial properties of substance exuded from Penicillium notatum (mold)“might have therapeutic value if it could be produced in quantity.”

7. HistoryPenicillin was isolated in 1939, and in 1944 Selman Waksman and Albert Schatz, American microbiologists, isolated streptomycin and a number of other antibiotics from Streptomyces griseus.

8. The story now…100,000 – 200,000 tons of antibiotics used worldwideUS Production = 22.7 million kilogramsAntibioticCAS NumberRankAmoxicillin26787-78-05Azithromycin83905-01-5 15Cephalexin15686-71-2 34Clavulanate Potassium61177-45-547Ofloxacin83380-47-665Levofloxacin100986-85-480Trimethoprim738-70-5 85Sulfamethoxazole723-46-686Ciprofloxacin 85721-33-1103http://products.coastalscience.noaa.gov/peiar/default.aspx

9. Livestock TherapyHuman TherapyOtherLivestockNon-Therapeutic%681570U.S. antimicrobial use Half from classes used in human medicine

10. Prospects for new antibiotics?New antibiotic development slowed in 80’s/90’sSelective drugs have lower market value5-15 yr time frame to get new drugs to physiciansRecent increase in new antibiotic development is encouraging

11. Antibiotic Resistance

12. Antibiotic Resistant Superbugs

13. History of Antibiotic Resistant Superbugs 1928 Fleming discovers penicillin1946 Penicillin resistant Staphylococci1969 US Surgeon General “Its time to close the book on Infectious Diseases”2010 Superbugs winning the raceRubinstein and Zhanel. Lancet Infect Dis 2007. Gin and Zhanel. 1996.EARSS Report 2009

14. How do bacteria become resistantPlasmids and moreReadily transferredEven to distantly related bacteriaConfirmed in human gut, mouthBacteria “teach” each other to outwit antibiotics

15. Resistance Mechanisms Inside the Bacterial CellAlteration in target site (eg. MRSA, VRE, PRSP)Inactivation/alteration of antibiotic (eg. B-Lactamases)Decreased uptake (eg. P. aeruginosa)Efflux (eg. S.aureus and fluoroquinolones)Murray B. 1998; Gin and Zhanel 1996.

16. Causes of Antibiotic Resistance Overuse/abuse of antibiotics in humansOveruse/abuse of antibiotics in non-humansDeveloping countriesWorld travel Critically ill patientsIndustry advertising/promotingZhanel. Treat Resp Med 2005.Gin and Zhanel. Annals Pharmacother 1996.Gin and Zhanel. Can Pharm J 2001.

17. Is antibiotic resistance new?No.It is natural, ancient and hard wired into microorganismsFound in cave system isolated from human activitiesBhullar et al. PLOS one. 7 (2012) e34953.

18. MRSAMRSA (Methicillin Resistant Staphylococcus aureus) Very difficult to treatFirst appeared as hospital derived infection1990s – Community associate outbreaks among high-risk populationsToday, colonization rates in general population ~ 1.5%Infections account for majority of skin and soft tissue infections treated in U.S. Emergency RoomsIn 2005, MRSA caused more deaths in US than AIDS

19. Presentation of MRSAMRSA presentation can include any of several disease manifestations However, the most common presentation are soft tissue infections such as boils, abscesses, furuncles, carbuncles etc.

20. Antibiotic Resistance as a Human Health ConcernEnteric pathogens such as Salmonella and EHEC (Enterohaemorrhagic Escherichia coli) causing illness and treatment failure Other multi-drug resistant organisms: Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosaRelatively few pathogens in nature, but…Antibiotic resistance is transferable!!!New antibiotics, not anytime soonCost of antibiotic resistance in the U.S. estimated in 2006 at $95 billion

21. Sources of Antibiotics and Antibiotic Resistances

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23. Where are antibiotic resistance genes (ARG) found?Hospital wastewaterAnimal production Sewage and leaking sewer pipesWWTPSurface waterGroundwaterDrinking water

24. Detection of ARGZhang et al., Appl Microbiol. Biotechnol. 2009. 82:397-414.Red: aminoglycoside; brown: chloramphenicol, + b lactam; blue: microlide; violet: sulfonamide; green: tetracycline; indigo: trimethoprim

25. Antibiotic Use in Developing CountriesAntibiotics available OTCPoor patient compliance (1-2 days)Cost (take subtherapeutic course)Antibiotic quality is lowcounterfeitadulteratedpoor quality (potency)Isteriz R. ICAAC 20003/2011: can’t purchase Antibiotic without Rx in Mexico

26. Human InputsExcretion of therapeutic antibiotics and metabolitesMany discrete directly in amounts > 40% of ingested doseDisposal of unused antibioticsFlushing down the toiletWashing topically applied antibioticsAll go to septic systems or municipal WWTPsInefficient removalBreeding grounds for antibiotic resistant organisms

27. 1 or more antibiotics found in 48% of streams sampled14 of 22 antibiotics detected at least onceConcentrations generally low (<0.5 ppb)Most frequently detected antibiotics: trimethoprim (27.4%), erythromycin-H2O (21.5%), lincomycin (19.2%), sulfamethoxazole (19.0%), tylison (13.5%)Antibiotics found in streams downstream of both intensive urban (68%) and livestock (39%) activityAntibiotics in Surface WaterKolpin et al. Environ Sci Technol 2002. 36:1202

28. Veterinary InputsAntibiotics used in livestock operations since the early 1950sUsed to treat infections, or to improve growth and feed efficiencyFour “types” of antibiotics use in livestock operationsTherapy: Antibiotics for treatment of frank clinical diseaseControl: Antibiotics administered to a herd or flock in which morbidity and/or mortality has exceeded baseline normsPrevention: Antibiotics used in animals considered “at risk”, but where individuals do not show signs of diseaseGrowth Promotion: Antibiotics administered over a period of time, usually as a feed additive, to growing animals

29. Antibiotics impact aquatic environment through manureLarge fraction of the medicines present unchanged in animal wasteDirect runoff or collection and use as fertilizerTetracyclines are used in humans and cattle/poultry/swineEstimated 3 million pounds of tetracyclines used annually for growth stimulation in livestock! 25-75% of tetracyclines administered to animals are excreted in the active formHileman, B. “Resistance is on the Rise” Chem. Eng. News 2001, February 19, 47.Kulshrestha, P.; Giese, R. F. Aga, D.S. Environ. Sci. Technol. 2004, 38, 4097.Boxall, A. B. A. EMBO Reports 2004, 5, 1110.Simon, N. S. Environ. Sci. Technol. 2005, 39, 3480.Oxytetracycline (OTC)

30. Antibiotic Use in Animals Source: CAHI 2005* Bacitracin, Bambermycins, Chloramphenicol, Florfencil, Nitrofurantoin, Nitrofurasone, Novobiocin, Polymyxin, Sodium Iodide, Virginiamycin

31. Decreasing concentration of antibiotics in environmentComposting of animal manure decrease concentration of antibioticsAbiotic processes rather than biodegradationAdsorption to soil componentshttp://www.nature.com/nchembio/journal/v8/n1/fig_tab/nchembio.745_F3.html

32. Methods for detection

33. How to detect antibiotics in water?Very sensitive, low-level detection available through GC/MS/MS and LC/MS/MSExample Minimum Reporting Limits (MRLs):Cyprofloxacin: 20 ng/LErythromycin: 50 ng/LSulfamethoxazole: 0.25 ng/LTrimethoprim: 140 ng/LApproximately $500 - $700

34. Common MethodUS EPA Method # 1694Pharmaceuticals and Personal Care Products in Water, Soil, Sediment, and Biosolids by HPLC/MS/MSDecember 2007http://www.epa.gov/waterscience/methods/method/files/1694.pdf

35. How do you determine antibiotic resistance?Isolate microorganisms thenMinimum inhibitory concentration (MIC)96 well platesClinical and Laboratory Standards Institute (CLSI). (2009). Performance standards for antimicrobial susceptibility testing; Vol. 29, No. 3Agar diffusion test against different AntibioticsMolecular tools to look for genes in water samples - filter, DNA extraction, PCR

36. Case Studies

37. Antibiotics occurrence in river, COWater Research 37 (2003) 4645-4656OTC= oxytetracylineCTC= chlortetracyclineDMC= demeclocyclineTC=tetracyclineDXC= doxycyclineMNC=minocyclineMCC=melocyclineS-- = Sulfonamides

38. Antibiotics in WWTP, WISci TotalEnv 361 (2006) 196-207

39. Reducing Antibiotics concentrations with veg buffersJ. Env. Qual. doi:10.2134/jeq2010.0141

40. The CAFO (Concentrated Animal Feeding Operation): Changes in Food Animal Production since 1930Factory farms – integrated production modelConcentrated, high volume housing and processingHighly intensive localizationBroad integration of food production and distributionRoutinely give antibiotics for prophylaxis

41. Swine CAFO increase ARGManure stored in deep pits or outdoor lagoons then applied to ag fieldsSurface water from run off Groundwater for leaksDown-gradient higher MIC in surface water and groundwater for erythromycin, tetracyclineHigher concentration of the AntibioticsSapkota et al. Env Health Per. 115 (2007) 1040-1045

42. Antibiotic Resistance Source TrackingE. coli from 2 spring in karstDifferent resistance of subpopulations linked to source of contamination (run-off vs. WWTP effluent)Ribeiro et al. FEMS Microbiol Ecol. 81 (2012) 267-280.

43. Antibiotics resistance in WWTP and GW below leaking sewerIsolates from WWTP and GW wells near leaking sewer linesWWTP: resistant to pencillin, ampicillin, vancomycin, erythromycin, sulfmethoxazoleGW: More variable but also included resistance to chloramphenicol Antibiotic-producing Actinomyces in soils increase resistanceMultiply resistance in bothAppl. Micro Biotech (2005) 69:106-112

44. Conclusions

45. Antibiotic Use in US: Animals vs. HumansCurrent estimated use/yearAnimals: 26.6 million lbsHumans: 3 million lbsReasonable estimate ~70% of all antimicrobials in North America are given to animalsSame classes of AntibioticsUnlike human waste, waste generated on farms does not undergo tertiary treatmentConcentration of antibiotics entering environment is higherFDA doesn’t limit amount of Antibiotics used by livestock producersMellon, et al. Union of Concerned Scientists, 2001Gorbach. 2001. NEJM. 345:1202

46. Antibiotic Use in US: Animals vs HumansCompare and ContrastAnimalsHumansIndividual TreatmentYes, by vet or caretakerYes, by MDMass TreatmentYes, oftenVery rarePreventive TreatmentOftenSeldom“Growth Promotion”YesNoDuration / doseLong / lowShort / high

47. Government Policy and Marketplace InitiativesGovernment policyPhaseouts of antibiotic feed additives in Sweden, Denmark, and then EU US – FDA, CongressMarketplaceRestaurant chains, suppliersMarket opportunities

48. Danish Growth Promoter Withdrawal ExperienceComplete withdrawal of antimicrobials for growth promotion or disease prevention but not therapeutics by end of 1999Antimicrobial use decreased 54% from 1994 to 2001Some increase in therapeutic use in pigs but not poultryDramatically reduced food animal reservoir AR enterococciNo measurable change in food-borne pathogen AR in humans (illness or commensal)Minimal impact on animal welfareEconomic impact: Modest decreased feed efficiency in weaners and poultry. GDP 0.03% decrease. (~1 euro/pig)WHO/CDS/CPE/2FK/2003.1

49. Antibiotics & resistance found in environmentSurface waterGroundwaterDrinking waterEmerging Contaminant and issueSources:WWTPCAFOSeptic Tanks

50. Impacts – Human health concern?Found at 1 ng/L – 1 ug/L levels in environmentTypical therapeutic doses = 100 – 250 mg per dose (3x per day?)Need to drinkNot likely an issue

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52. Questions