PACCARB Day 2 Presentation: Drivers of AMR and Antibiotic Metabolites in the Environment

PACCARB Day 2 Presentation: Drivers of AMR and Antibiotic Metabolites in the Environment


>>SO AT THIS POINT I’M GOING TO TURN THE
PROGRAM OVER TO OUR FIRST MODERATOR, DR. RANDY SINGER.
>>GREAT. ARE WE READY?
ALL RIGHT. ON BEHALF OF DR. AILEEN MARTY AND MYSELF I
WOULD LIKE TO WELCOME YOU TO A REALLY EXCITING SYMPOSIUM ON ANTI-MICROBIAL RESISTANCE AND
ANTIBIOTIC RESIDUES IN THE NATURAL ENVIRONMENT. WE HAVE AN INCREDIBLE LINEUP OF SPEAKERS,
MANY HAVE FLOWN A LONG WAY TO BE HERE. WE’RE GOING TO CONTINUE A CONVERSATION WE
STARTED IN MARCH AT OUR PACCARB MEETING, SO AT THAT MEETING WE HAD A ONE HEALTH SYMPOSIUM,
I SPOKE ON ENVIRONMENTAL HEALTH ISSUES, ANTI-MICROBIAL RESISTANCE AND HIGHLIGHTED MANY DATA GAPS
THAT EXIST AS WE STUDY ANTIMICROBIAL RESISTANCE IN THE NATURAL ENVIRONMENT AND LINK TO HUMAN
AND ANIMAL HEALTH. WE’RE GOING TO CONTINUE THAT TODAY WITH THESE
DISTINGUISHED GROUP OF SPEAKERS. THIS SYMPOSIUM WILL BE DIVIDED INTO THREE
SECTIONS, WE’LL START WITH THE SECTION ON THE DRIVERS OF ANTI-MICROBIAL RESISTANCE AND
ANTIBIOTIC METABOLITES IN THE NATURAL ENVIRONMENT. HOW ARE ANTIBIOTICS USED IN HUMANS, ANIMALS
AND CROPS AND HOW DOES RESISTANCE AND ANTIBIOTIC METABOLITE THEN DISSEMINATE INTO THAT NATURAL
ENVIRONMENT. IN THE SECOND SESSION WE’LL MOVE INTO SOME
OF THE CRITICAL ENVIRONMENTAL COMPARTMENTS THAT NEED TO BE EVALUATED, FOCUSING ON WASTEWATER,
MANURE, SOIL, AND WATER. AND THEN WE’LL FINISH WITH THE SESSION ON
SURVEILLANCE ACTIVITIES AND U.S. GOVERNMENT ACTIVITIES IN THIS ARENA STARTING WITH THE
TALK ACTUALLY ON CHEMISTRY OF ANTIBIOTIC METABOLITES BECAUSE IT IS REALLY COMPLICATED TO STUDY
THE ANTIBIOTIC METABOLITES IN THE NATURAL ENVIRONMENT AND PROCEED WITH TALKS FROM EPA,
USGA, AND USDA ARS. I WANT TO APOLOGIZE GOING FORWARD THAT WE
ONLY ARE ABLE TO GIVE EACH SPEAKER TEN MINUTES. I MEAN, IT’S KIND OF RIDICULOUS TO BE HONEST.
THESE EXPERTS COULD SPEAK AND HAVE US CAPTIVATED FOR AN HOUR EASILY ON EACH TOPIC.
WE’RE LIMITING THEIR TIME TO TEN MINUTES AND WE ALSO GAVE THEM SEVERAL QUESTIONS THAT WE’RE
HOPING THEY WILL BE ABLE TO ADDRESS, FIRST BEING HOW SHOULD THIS NATURAL ENVIRONMENT
ISSUE BE ADDRESSED IN CARB OR THE NATIONAL ACTION PLAN GOING FORWARD.
SECOND, WHAT IS THE CONNECTION BETWEEN THIS NATURAL ENVIRONMENT AND HUMAN AND ANIMAL HEALTH,
AND FINALLY HOW SHOULD WE PRIORITIZE SOME OF THESE DATA GAPS THAT WILL BE DISCUSSED
TODAY AS WE MOVE FORWARD IN THIS ARENA. SO THIS IS A REALLY TALL TASK TO DO IN TEN
MINUTES. I’M HOPING THEY WILL SUCCEED.
NOW I WANT TO GIVE ANOTHER APOLOGY HERE THAT I NEED TO INFORM EVERYONE THAT DR. DOUG CALL,
WHO WAS SUPPOSED TO GIVE THE SECOND TALK TODAY ON THE ANIMAL ASPECT, IS UNABLE TO MAKE IT
TODAY. SO I WILL BE DELIVERING HIS PRESENTATION ON
HIS BEHALF. IT WILL BE HIS PRESENTATION WITH HIS OPINIONS,
HIS DATA, HIS CONCLUSIONS AND IT’S NOT MY FIRST CHOICE TO DO IT THIS WAY BUT CIRCUMSTANCES
DICTATED THAT WE DO IT. SO I APOLOGIZE.
OKAY. I’M GOING TO MOVE TO OUR FIRST SPEAKER THEN.
IT IS MY TRUE PLEASURE TO INTRODUCE DR. DAVID GRAHAM, PROFESSOR OF ECOSYSTEMS ENGINEERING
AT NEWCASTLE UNIVERSITY AT THE U.K. AND HAS DONE SOME PHENOMENAL WORK THAT HOPEFULLY HE
WILL BE ABLE TO SUMMARIZE VERY WELL IN TEN MINUTES
>>I WAYS ASKED TO TALK ABOUT RELATIONSHIPS BETWEEN HUMAN USE AND ENVIRONMENTAL DISCHARGE,
I’LL ESTABLISH BASELINE TERMS FOR THE PRESENTATION. ANTIBIOTIC RESISTANCE IS THE MUTATIONS OR
ACQUISITION THAT REDUCE RISK OF ANTIBIOTIC, TWO MAIN DRIVERS OF RESISTANCE, ONE IS USE
WHICH IS THE FOCUS OF MOST PEOPLE’S EFFORTS AND BEING AFFECTED BY INDUSTRIAL ACTIVITY
WHICH I’LL HIGHLIGHT VERY BRIEFLY IN THE MIDDLE OF THE TALK.
ANTIBIOTICS ARE USED, TAKEN INTO THE GUT IN HUMANS AND ANIMALS, IN THE GUT YOU GET THE
SELECTION OF RESISTANCE GENES AND BACTERIA. THAT’S THE CONSEQUENCE OF THE ANTIBIOTIC.
THE PROBLEM IS THAT THAT SELECTION PROCESS THEN RELEASES GENES AND BACTERIA IN THE FECAL
MATTER FROM THE USER. THAT FECAL MATTER ENTERS THE ENVIRONMENT.
NOW, WHEN IT COMES TO THE BACTERIA THAT ARE LIVING IN YOUR GUT THEY LIKE WARM PLACES WITH
LOTS OF ORGANIC MATTER. IN THE REAL WORLD IT’S MORE DILUTE AND WHAT
HAPPENS IS THE BACTERIA TEND TO BE� IN YOUR GET TEND TO BE SELECTED AWAY FROM IN THE ENVIRONMENT
BUT RESISTANCE GENES ARE EXCHANGED, PHAGE IS TRANSMITTED IN THE ENVIRONMENT, BETTER
ADAPTED TO THE ENVIRONMENT. OUR DEFINITION OF THE ENVIRONMENT IS HUMAN
ANIMAL BUT ALSO ECOSYSTEMS. IT’S THE LARGER ENVIRONMENT ON GLOBAL SCALES
WHICH IS A LOT OF THE WORK WE’VE BEEN TRYING TO DO.
NOW, RELATIVE TO THE RELATIONSHIP BETWEEN USE AND EXPOSURE, IT DEPENDS UPON WHERE YOU
ARE IN THE WORLD. IN A DEVELOPED COUNTRY, THE HEADING ON THAT
SLIDE IS INCORRECT, THIS IS THE MODEL FOR A DEVELOPED COUNTRY.
BASICALLY IN A DEVELOPED COUNTRY ANTIBIOTIC USE AND CONSUMPTION IS THE PRIMARY EXPOSURE
PATHWAY. THE WASTE, WASTE WATER SYSTEM THAT GETS TREATED,
EFFLUENTS GO INTO THE WATER SUPPLY WHICH IS TREATED BOTH RELATED TO WATER AND FOOD CONSUMPTION.
NOW, THAT IS VERY DIFFERENT THAN THE DEVELOPING WORLD THAN EMERGING WORLD.
THIS IS WHERE THINGS ARE QUITE DIFFERENT, THIS IS WHERE THINGS ARE QUITE IMPORTANT.
IN THE DEVELOPING AND EMERGING WORLD LEVEL OF WASTE TREATMENT IS MUCH LESS.
AS A CONSEQUENCE FREQUENTLY THE WASTE SITE OF ONE PERSON IS WATER SOURCE FOR THE NEXT
PERSON, WITH HIGH LEVELS OF RESISTANCE GENES, POSSIBLY RESISTANT BACTERIA THEN THE INDIVIDUALS
THAT HAVE NOT BEEN TAKING ANTIBIOTICS BUT ONLY TAKING THE WASTE ARE STARTING TO ACQUIRE
RESISTANCE IN THEIR GUT WITHOUT USE. YOU SEE MUCH, MUCH HIGHER LEVELS OF EXPOSURE
TO RESISTANCE POTENTIAL, PARTICULARLY GENETIC RESISTANCE IN EMERGING COUNTRIES.
THE RELEVANCE TO PLACES LIKE THE UNITED STATES, CONTINENTAL EUROPE AND SO FORTH IS AS COUNTRIES
EMERGE ECONOMIES IMPROVE AND INTERNATIONAL TRAVEL BECOMES WIDER AND THEREFORE YOU’VE
GOT A PATHWAY THROUGH TRAVEL AND OTHER POSSIBLE MECHANISMS LIKE WILDLIFE OF EXTENDING TO THE
WORLD, AND A PAPER OUT OF DENMARK LOOKS AT ADDRESSING THIS INCLUDING POTENTIAL SURVEILLANCE
APPROACHES. NOW IT’S VERY DIFFICULT TO FIND CASES WHERE
YOU DEMONSTRATE WHERE I’M TALKING ABOUT, THE ACTUAL EFFECTS OF THIS ON HEALTH BUT WE DO
SEE THROUGH LOOKING AT LARGE ANIMAL FEED LOTS, THIS IS WORK WE’RE DID TEN YEARS AGO, WE WANTED
TO LOOK AT AN ANALOG SYSTEM FOR HUMAN USE BUT USE ANIMAL FEED LOTS AT OUR MODEL, THIS
WAS IN� WE QUANTIFIED RESISTANCE IN 25 FEED LOT LAGOONS, CATTLE FEED LOTS, SUBCATEGORIZED
INTO LEGALLY OR FUNCTIONAL ORGANIC, RECEIVED ANTIBIOTICS THERAPEUTICALLY, ALMOST ALWAYS
THROUGH QUARANTINING BUT THEN THE ANIMAL MAY BE RETURNED BACK TO THE HERD CONDITIONALLY
VERSUS FEED LOTS WITH THERAPEUTIC AND NONTHERAPEUTIC ANTIBIOTIC USE.
WHAT WAS THE MOST ASTOUNDING THING TO US WAS THAT WE FOUND THAT WE EXPECTED THAT THE NONTHERAPEUTIC
USE WOULD HAVE A MUCH BIGGER EFFECT THAN IT DID.
WE SAW HIGHER LEVELS OF RESISTANCE GENES AND RESISTANT E. COLI WHICH WE MEASURED BUT I
DON’T REPORT. IN THE LAGOONS THAT ONLY HAD THERAPEUTIC USE.
NOW, FOR YEARS WE NEVER UNDERSTOOD WHY THIS WAS THE CASE, IT WASN’T UNTIL WE STARTED WORKING
IN INDIA WE STARTED TO UNDERSTAND, THERAPEUTIC USE WAS OCCURRING AND THE USE WAS DISCONNECTED
FROM THE LARGE PORTION OF THE HERD. THE QUESTION IS WHAT IS ACTUALLY GOING ON?
I’LL TALK ABOUT THAT. THAT’S THE PRIMARY COMPONENT OF MY TALK AT
THE END. I’M GOING TO GO ON ONE VERY BRIEF TANGENT
AND THIS IS RELATED TO INDUSTRIAL USE, THIS IS WORK WE DID IN CUBA.
WE WANTED TO STUDY CUBA AFTER HAVING WORKED ON ANIMAL SYSTEMS IN THE UNITED STATES AND
CANADA BECAUSE CUBA IS VERY, VERY PRUDENT IN TERMS OF ANTIBIOTIC USE.
THEY’VE GOT A VERY CONTAINED MEDICAL SYSTEM RELATIVE TO ANTIBIOTIC USE, AT LEAST THEY
CLAIM ANTIBIOTICS ARE FUNCTIONALLY NOT USED IN AGRICULTURE.
WHAT WE FOUND WAS VERY HIGH LEVELS OF RESISTANCE IN THE ENVIRONMENT BUT ALMOST ALL ASSOCIATED
WITH INDUSTRIAL WASTE, AND HUMAN WASTE. I HIGHLIGHT, THIS IS THE GRAPH THAT REPRESENTS
THE STRETCH OF THE RIVER, THE AMANDARIS RIVER IN HAVANA.
WE SAW BACTERIA, AS A FUNCTION OF DIFFERENT TYPES OF WASTE INPUTS ALONG THE RIVER.
WHAT’S NOTEWORTHY HERE IS THAT THE HEAVY METAL INDUSTRIAL WASTE INPUT, COLLEAGUES AT THE
UNIVERSITY HAVANA DID WORK, THE HUGE MAJORITY OF ISOLATES WERE RESISTANT TO ANTIBIOTIC,
BECAUSE OF THE HARSHNESS OF ENVIRONMENT. SO GETTING TO MY CASE RELATED TO DIRECT HUMAN
EFFECTS, IT’S RELATED TO WORK WE’RE DOING IN INDIA.
THE REASON WHY WE WANTED TO WORK IN THE SITE IN INDIA WAS BECAUSE THE AREA IS PART OF THE
GANGES, EXTREMELY BEAUTIFUL, PRISTINE, WHERE HINDUS PARTICULARLY GO ON ANNUAL PILGRIMAGES,
PARTICULARLY IN MAY AND JUNE. WE WANTED TO CONTRAST ABUNDANCE OF RESISTANCE
GENES IN THE FUNCTIONAL RESISTOMES IN THE GUT OF PEOPLE RESIDENT IN THE PRISTINE AREAS
VERSUS PEOPLE THAT VISIT THEM. THE KEY THING TO REALIZE PRACTICALLY THE POPULATION
OF THIS AREA IS ABOUT 300,000, WASTE TREATMENT CAPACITY IS 150,000, AND FOR THOSE MONTH,
MONTH AND A HALF IN JUNE, MAY AND JUNE, POPULATION GOES TO 1 TO 1.5�MILLION, TYPICAL EVERY
YEAR, AND EVERY 12 YEARS IT GOES UP TO 12�MILLION. SO YOU’VE GOT AN ENVIRONMENT WHERE YOU’VE
GOT A HUGE NUMBER OF PEOPLE COMING FROM AROUND THE WORLD BUT PRIMARILY URBAN INDIA TO A PLACE
THAT’S VERY PRISTINE. WE’VE GOT AN IDEAL WAY OF CONTRASTING THE
FLUENCE OF THE GRANDER ENVIRONMENT ON THE RESISTOME IN THE GUTS OF INDIVIDUALS.
I’M NOT GOING TO PROVIDE YOU ALL THE DATA BECAUSE THAT’S THE OTHER 50 MINUTES OF MY
TALK BUT FOR NOW I’LL PROVIDE YOU A COUPLE HIGHLIGHTS FOR THE SAKE OF CONVERSATION.
WHAT WE’VE FOCUSED ON IN THE WORK WE’VE REPORTED SO FAR IS THE RESISTANT ISOLATES IN BLANDM1.
THE RIVER IN DELHI IS EXCEPTIONALLY POLLUTED AND LOOKED AT ABUNDANCE OF BLANDM1 IN SEASON
VERSUS PILGRIMAGE AND NONPILGRIMAGE. YOU SEE TWO ORDERS IN THE GANGES WHEN THE
PILGRIMS ARE THERE, SOME ELEVATED MORE THAN OTHERS, BUT NO SEASONAL DIFFERENCES IN DELHI
AND THAT’S BECAUSE THERE’S NO PILGRIMAGE OCCURRING THERE.
NOW YOU CAN ARGUE THAT THE REASON WHY YOU SEE THAT GREAT INCREASE IS BECAUSE THERE’S
1 TO 1.5�MILLION PEOPLE THERE, IT’S JUST A FUNCTION OF A LOT OF PEOPLE.
WE FIGURED WE HAD TO TRY AND UNDERSTAND THAT SO WE BASICALLY DID ESTIMATES OF THE ABUNDANCE
OF THE GENE PER CAPITA, ACCOUNTING FOR THE FACT THERE’S PILGRIMS VISITING.
WHEN WE DID THAT IN THE CALCULATION WE FOUND TWO HAVING THINGS.
FIRST FOR MANY RESISTANCE GENES WE LOOKED AT NOT NDM1, IT DIDN’T VARY FROM LOCATION
TO LOCATION. BUT IF YOU LOOK AT BLANDM1, WE SAW HIGHLY
ELEVATED LEVELS FROM THE PEOPLE WHO WERE VISITING RELATIVE TO THE PEOPLE WHO WERE RESIDENT IN
THIS PRISTINE AREA. WHAT WE WERE FUNCTIONALLY SEEING WAS THE REALTIME
MOVEMENT OF ELEVATED RESISTOMES IN THE GUT OF INDIVIDUALS MOVING FROM URBAN POLLUTED
ENVIRONMENTS TO PRISTINE ENVIRONMENTS. THIS DATA IS, WHAT I’VE SHOWN YOU IS GENETIC.
WE’RE NOT JUST LOOKING AT GENES. WE’RE LOOKING AT BACTERIA OF MEDICAL AND HEALTH
RELEVANCE. THIS IS A SUITE OF GRAM NEGATIVE, THE RED
COLUMNS ARE E. COLI, YOU CAN LOOK AT THE DETAILS OF THE OTHERS BUT THE BOTTOM LINE IS THE AREAS
WHERE THERE’S PEAKS, THOSE ARE THE BATHING AREAS FOR PILGRIMS, IN FACT THEY ARE BOTH�
THERE’S HIGH LEVELS OF GENES AND PROSPECTIVELY RESISTANT PATHOGENS IN THE VICINITY AS WELL.
THE KEY IS THE PATHOGENS ARE BEING EXPOSED TO INDIVIDUALS WHO ARE THEN IN THE AREA FOR
A COUPLE WEEKS AND THEN THEY ARE RETURNING HOME WHICH COULD BE ANYWHERE IN THE WORLD.
SO UNTIL SUMMARY THIS IS MY PERSPECTIVE, THESE ARE MY OBSERVATIONS.
ANTIBIOTIC USE IS CENTRAL TO RESISTANCE DEVELOPMENT IN EVOLUTION.
HOWEVER, I THINK POOR WATER QUALITY AND INADEQUATE WASTE MANAGEMENT ON REGIONAL LEVELS IS PROBABLY
THE MAIN DRIVER OF GLOBAL SPREAD OF RESISTANCE. DEVELOPED COUNTRIES LIKE THE U.S., U.K., CONTINENTAL
EUROPE HAVE BECOME COMPLACENT BECAUSE THEY LIVE WHERE THEIR WATER IS CLEAN.
YOU THINK ABOUT VICTORIAN ENGLAND, THE CHOLERA EPIDEMIC WERE WATERBORNE, THOSE DON’T HAPPEN
ANYMORE BECAUSE WE’VE GOT CLEAN WATER AND IT’S CHANGED THE WAY WE THINK ABOUT RESISTANCE
AND HEALTH. A R IS MASSIVELY DISCHARGED WHERE WASTE MANAGEMENT
IS INADEQUATE AND INTERNATIONAL TRAVEL RELATED TO EXPOSED HUMANS AND EXPOSED WILDLIFE MAY
BE THE MAIN REASON WHERE WE’RE SEEING IT SPREAD AT THE RATE AT WHICH WE SEE IT SPREAD.
LOOKING AT ONE OF THE ORIGINAL THINGS FOR THE PARTICULAR MEETING WAS TO LOOK AT ONEHEALTH
AND THE PACCARB POLICY, THERE’S NO MENTION OF WASTE IN THE GULF AND I THINK WASTE POSSIBLY
CONTRIBUTES A HUGE LEVEL OF� HUGE CONTRIBUTORS TO A R SPREAD ON GLOBAL SCALES.
SURVEILLANCE SHOULD NOT BE JUST ASSOCIATED WITH HOSPITALS OR DOMESTIC BUT SHOULD INCLUDE
INTERNATIONAL. I PROVIDE ONE EXAMPLE AS TO HOW YOU MIGHT
CONSIDER DOING THAT. SO THANK YOU.
>>THANK YOU SO MUCH, PROFESSOR GRAM. YOU DID IT.
A LITTLE OVER TEN MINUTES. THANK YOU.
OKAY. WE’RE GOING TO CONTINUE ON BECAUSE WE HAVE
A 20MINUTE Q&A AFTER THESE THREE SPEAKERS. THE NEXT TALK IS BY DOUG CALL WHICH I WILL
DO ON HIS BEHALF. AGAIN, THE SLIDES ARE HIS, DATA ARE HIS, I
WILL BE INTERPRETING BASED ON OUR CONVERSATION, SO OPINIONS AND INTERPRETATIONS ARE ALL OF
DOUG’S. I GET TO KEEP MYSELF TO TEN MINUTES.
I THINK THIS TALK WILL TIE WELL WITH PROFESSOR GRAHAM’S BECAUSE WHAT WE’RE GOING TO TALK
ABOUT ON THE ANIMAL SIDE IS THIS RELATIONSHIP BETWEEN ANTIBIOTIC USE, DOSE THAT YOU WOULD
PROVIDE TO THAT ANIMAL, CONCENTRATION OF THE ANTIBIOTIC METABOLITE THAT YOU MIGHT FIND
IN THAT ANIMAL’S ENVIRONMENT AND ITS EFFECT ON NUMBER OF RESISTANT BACTERIA IN THAT ENVIRONMENT.
IF YOU ASKED THE BEST WAY TO IMPACT, YOU MAY GET A DIVERSITY OF RESPONSES.
DR. CALL’S APPROACH THROUGH THIS TALK WAS REALLY TO FOCUS ON WHAT HE FEELS WOULD BE
THE MOST IMPACTFUL POINT OF INTERVENTION. AGAIN, IT’S GOING TO TIE INTO BOTH DOSE, CONCENTRATION,
AND THE PROPORTION OF RESISTANCE. NEXT SLIDE.
SO IF WE FOCUS ON THE ANTIBIOTIC AND DOSE THAT’S GIVEN TO THE ANIMAL OR THE CONCENTRATION
OF THE ANTIBIOTIC METABOLITE THAT YOU MIGHT FIND IN THE ENVIRONMENT YOU’RE LOOKING AT
A THEORETICAL CONSTRUCT ON THE Y AXIS ANTIBIOTIC CONCENTRATION GOING FROM EXTREMELY LOW TO
EXTREMELY HIGH. IN YOU WERE AT THAT EXTREMELY LOW LEVEL ALL
BACTERIAL POPULATIONS WILL GROW, SUSCEPTIBLE AND RESISTANT.
AS YOU START TO INCREASE THAT CONCENTRATION YOU’LL PUT MORE SELECTIVE PRESSURE ON THAT
POPULATION, SELECTING FOR MORE RESISTANCE. AND THAT WILL CONTINUE ALL THE WAY TO THE
POINT WHERE YOU COMPLETELY SUPPRESS ALL GROWTH OF BACTERIA THAT WOULD BE SUSCEPTIBLE TO THE
ACTION OF THAT ANTIBIOTIC. THE POINT THAT DR. CALL IS MAKING HERE IS
THAT IF YOU WERE TO LOOK IN THE ENVIRONMENT OF THE ANIMAL, DIRECTLY WHERE THAT ANTIBIOTIC
METABOLITE IS GOING TO BE EXCRETED MIGHT BE A CONCENTRATION THAT IS EXTREMELY HIGH, SUPPRESSING
THE GROWTH OF ANY BACTERIA EVEN IF THEY POSSESS RESISTANCE BUT THERE’S GOING TO BE A DIFFUSION
OF THAT METABOLITE OUTWARD. HOW DO YOU BEGIN TO UNDERSTAND WHAT THE IMPACT
IN THE ENVIRONMENT WILL BE OF THIS ENVIRONMENTAL CONCENTRATION?
NEXT SLIDE. NEXT SLIDE.
THANK YOU. SO WHAT WE’RE LOOKING AT HERE NOW IS A THEORETICAL
SPATIAL MODEL, YOU SEE ON THE X AND Y AXIS IT’S IN METERS, 2 DIMENSIONAL SPACE.
ANIMAL POPULATION IS EXCRETING ANTIBIOTIC WITH HIGHEST CONCENTRATION OF METABOLITE AT
THE POINT OF EXCRETION. DEPENDING ON HOW WASTE PRODUCTS ARE BEING
SPREAD, URINE, FECES, THERE’S GOING TO BE A DIFFUSION, THE ANTIBIOTIC CONCENTRATION
WILL DIFFUSE OUTWARD FROM THAT POINT. YOU’RE GOING TO HAVE A DIFFERENTIAL SELECTION
PRESSURE IN THE ENVIRONMENT, SIMILAR TO IF YOU WERE TO DO A KIRBY BAUER ON A PLATE.
THIS IS DIFFERENT THAN IN VITRO STUDY WHERE YOU MAY PUT ANTIBIOTIC IN A TUBE, MIX AND
EVALUATE THE EFFECT, THAT’S NOT WHAT’S GOING TO OCCUR IN THE ENVIRONMENT WHERE YOU HAVE
THIS SPATIAL PATTERN WITH A DIFFUSION OF THAT ANTIBIOTIC.
SO THERE’S GOING TO BE AREAS OF HIGH INTENSE SELECTION PRESSURE ALL THE WAY DOWN TO NO
ELECTION PRESSURE. NEXT SLIDE PLEASE.
SO THE SITUATION WE HAVE THEN WE CAN THINK ABOUT IT IN TERMS OF THE NUMBER OF BACTERIA
AND RESISTANT BACTERIA THAT WOULD BE ABLE TO GROW IN THAT SPATIAL STRUCTURE OF DIFFERING
ANTIBIOTIC CONCENTRATIONS. AT THE POINT OF EXCRETION MAYBE YOU’RE GOING
TO HAVE VERY ALSO GROWTH DUE TO THE HIGH CONCENTRATION, AS YOU SPREAD OUT THERE WILL BE IN THEORY
MORE RESISTANCE AT THE POINT WHERE ONLY THE RESISTANT BACTERIA ARE ABLE TO GROW.
WHAT YOU SEE ON THE Y AXIS HERE IS A PROBABILITY OF TRANSMISSION WHICH DR. CALL IS BASICALLY
SAYING AS THE ABILITY OF ANY OTHER ANIMAL TO PICK UP RESISTANT BACTERIA IN THE ENVIRONMENT
AND ON THE X AXIS IS THE NUMBER OF BACTERIA, WHAT HE’S DEFIND HERE IS ID50, NUMBER OF RESISTANT
BACTERIA THAT NEED TO BE PRESENT IN THE ENVIRONMENT FOR THAT ANIMAL POPULATION TO PICK UP WHAT
IS PRESENT. SO IF WE START TO THINK ABOUT COMBINING THE
ANTIBIOTIC EXCRETION PROFILE THAT ENVIRONMENTAL SPREAD AND AMOUNT OF RESISTANCE THERE WE CAN
BEGIN TO UNDERSTAND HOW AN ANIMAL IN ITS SPATIAL LOCATION, THE RISK OF ACQUIRING AND SPREADING.
ID50 WOULD BE NUMBER OF BACTERIA, RESISTANT BACTERIA THAT MIGHT INFECT OR COLONIZE 50%
OF THE ANIMAL POPULATION. NEXT SLIDE PLEASE.
SO THE STUDY THAT WE’RE GOING TO USE NOW OF DR. CALL’S TO DEMONSTRATE THIS POINT ARE ALL
GOING TO BE BASED ON A DAIRY EXAMPLE AND PRIMARILY AROUND E. COLI.
HERE ARE TWO DIFFERENT STUDIES TO DEMONSTRATE THIS POINT AND ITS RELATIONSHIP OR IMPORTANCE
TO DOSE. IF YOU LOOK ON THE GRAPH UP ON THE TOP LEFT,
WHAT YOU’RE LOOKING AT HERE IS EXPERIMENT WHERE CALVES WERE GIVEN A DISEASE PREVENTION
DOSE OVER THREE WEEKS, THE PLUS COLUMNS REPRESENTED TREATED, MINUS THOSE THAT DID NOT GET TREATMENTED.
THIS IS A LOWER DOSE OF OXY TETRACYCLINE, WHAT IS HAPPENING IN THE ANIMAL POPULATION
IN RESPONSE TO THAT LOWER DOSE? IF YOU FOCUS ON THE BAR THAT SAYS SSUT, THAT
WOULD BE THE E. COLI POPULATION WITH THE RESISTANCE PROFILE TO STREP SULFA TET PATTERN.
THERE WAS NO EFFECT IN THIS STUDY OF THAT LOW DOSE OF OXYTETRACYCLINE ON THE PREVALENCE
OR ENUMERATION OF THOSE RESISTANT E. COLI. IN FACT, THE TM MINUS GROUP HAD A HIGHER PERCENTAGE
OF ISOLATES, LOW DOSE DIDN’T HAVE AS STRONG EFFECT, IF YOU LOOK ON THE LOWER RIGHT THIS
IS A DIFFERENT STUDY, WITH A HIGH DOSE OF A DIFFERENT DRUG IDEALLY THE SAME DRUG AT
HIGHER DOSE, BUT YOU’VE GOT THIS NOW GIVEN TO CALVES TWO MGS/KG OVER TWO DAYS, THE LINE
THAT HAS THE CLOSED CIRCLES REPRESENTS THE TREATED GROUP, OPEN CIRCLES REPRESENT NONTREATMENT
GROUP, Y AXIS WITH RESISTANCE. AFTER TREATMENT YOU SEE PERHAPS A THREE LOG
INCREASE IN THE AMOUNT OF RESISTANT E. COLI BEING SHED FROM THESE TREATED ANIMALS.
IT’S DR. CALL’S CONCLUSION THAT DOSE DOES MAKE A DRAMATIC IMPACT ON THE AMOUNT OF RESISTANCE
THAT’S BEING SHED OUT OF THIS ANIMAL AND SO THAT RAISES THE QUESTION WHAT IS HAPPENING
THEN IN THE ENVIRONMENT OF THE ANIMAL. NEXT SLIDE PLEASE.
SO WHAT HE WANTED TO KNOW THEN WAS WHAT IS HAPPENING IN THE ENVIRONMENT AND WHAT IS HAPPENING
WITH THE ANTIBIOTIC CONCENTRATION OF THESE METABOLITES THAT MIGHT BE EXCRETED?
WHAT HE DID IN THIS STUDY WAS ON THE X AXIS YOU SEE A VARIETY OF ANTIBIOTICS, ALL PREPARED
AT 200 PARTS PER MILLION. THEY WERE MIXED WITH DIFFERENT SOILS.
YOU SEE THREE DIFFERENT SOILS, SILT LOAM, SANDY LOAM AND SAND.
HE EXTRACTED AFTER MIXING AND USED IN THE PRESENCE OF ANTIBIOTIC SENSITIVE STRAINS OF
E. COLI, SO THAT IF THERE WAS ACTIVE ANTIBIOTIC METABOLITE STILL PRESENT IN THIS SOIL MIXTURE,
IT WOULD INHIBIT THE GROWTH OF THE BACTERIA. SO ON THE ANTIBIOTICS WHERE YOU SEE NO BAR,
THAT REPRESENTS COMPLETE SUPPRESSION OF THAT SUSCEPTIBLE E. COLI POPULATION.
YOU CAN SEE THE SUPPRESSED GROWTH OF THE SUSCEPTIBLE E. COLI STRAINS IN ALL OF THE THREE SOIL TYPES.
IF YOU GO TO THE TETRACYCLINE, SUSCEPTIBLE BACTERIA CONTINUE TO GROW, PERHAPS A STATEMENT
TETRACYCLINE IS NOT AS ACTIVE IN CERTAIN SOIL TYPES, REGARDLESS WHAT WE DO KNOW IS THESE
ANTIBIOTIC METABOLITES BEHAVE DIFFERENTLY IN DIFFERENT SOIL TYPES, THAT WILL COME OUT
IN THE OTHER TALKS, BUT THERE IS VARIATION AND IT GIVES US SOME INDICATION OF THE KIND
OF WORK WE NEED TO DO IN THE ENVIRONMENT TO BETTER UNDERSTAND THE RELATIONSHIP BETWEEN
THESE ANTIBIOTIC METABOLITES, SELECTION OF RESISTANCE AND THEN THE SPREAD OF THE BACTERIA.
NEXT SLIDE PLEASE. SO WHAT DOES THIS LOOK LIKE IN THE REAL WORLD?
WHAT YOU’RE LOOKING AT HERE IS A STUDY, AGAIN THE SAME STUDY, DIFFERENT PIECE OF IT, WHERE
ON THE X AXIS WE HAVE TIME SO DAYS AND ON THE Y AXIS WE HAVE THIS COUNT OF E. COLI AND
SO WE’RE LOOKING AT THE LOG NUMBER OF E. COLI OVER TIME RESISTANT TO SEF.
DAY ZERO CALVES TREATED WITH STANDARD DOSE AND WHAT YOU SEE WHEN IT SAYS TREATED SOIL,
THAT’S THE TREATED CALF AND SAMPLE FROM THE SOIL, ELEVATION IN THE AMOUNT OF RESISTANCE
TO E. COLI. THE LINE THAT SAYS TREATED FECES WOULD BE
THE CALVES THAT WERE TREATED. YOU CAN SEE THEIR FECES ARE AN INCREASE IN
RESISTANCE BUT IT BEGAN TO DROP AFTER DAY TEN.
THE SOIL NUMBERS STAYED ELEVATED OVER AN EXTENDED PERIOD OF TIME.
SO REALLY THAT ENDS UP RAISING TWO QUESTIONS. IS THE INCREASE IN THE SOIL BACTERIA THAT
ARE RESISTANT TO THIS COMPOUND, IS THAT DUE TO THE MORE FECAL SHEDDING OF BACTERIA THAT
THEN PERSIST OR IS IT DUE TO THE RESIDUES FROM THESE, URINE WOULD BE THE PRIMARY ROUTE
OF EXCRETION, THAT IS SELECTING FOR RESISTANCE BACTERIA ALREADY IN THE SOIL.
THE SECOND QUESTION, IS THAT RESULTING POPULATION SIZE OF BACTERIA IN THE SOIL SUFFICIENTLY
HIGH TO BE ABLE TO COLONIZE ADDITIONAL ANIMALS. NEXT SLIDE PLEASE.
SO HE CONTINUES THIS WORK TO TRY TO EVALUATE THAT FIRST QUESTION WHICH IS ABOUT IS THE
RESIDUE� THE METABOLITE EXCRETED FROM THESE ANIMALS ACTUALLY SELECTING, AND SO WHAT HE
DID WAS USE A GFP LABELED E. COLI IN THE BEDDING OF THE CALVES, AT DAY ZERO YOU CAN SEE TREATED
BEDDING AND UNTREATED BEDDING AT THE SAME LEVEL, ALL THE BEDDING GOT THE SAME AMOUNT
OF GFP LABELED E. COLI. HE WILL TREAT SOME CALVES, THAT’S THE TREATED
LINE, NOT TREAT OTHERS, THAT’S THE UNTREATED LINE.
WHAT YOU SEE IS THAT THE TREATED ANIMALS ON SAME BETTING SAW INCREASE AMOUNT OVER TIME,
IT BEGAN TO DROP IN THE UNTREATED BEDDING. HIS CONCLUSION HERE WAS THAT THERE WAS AN
INCREASE IN RESISTANT E. COLI POPULATION IN THE BEDDING DUE TO THE EXCRETION OF THE ANTIBIOTIC
METABOLITE ITSELF. BY DAY THREE OR FOUR THERE’S AN INCREASE IN
THE AMOUNT OF THE FECES OF TREATED CALVES THAT COULD BE DUE TO ACQUISITION FROM THE
ENVIRONMENT BUT BY THE TIME YOU GET TO THAT POINT IT’S HARD TO DISTINGUISH THE AMOUNTS
IN THE BEDDING, IS IT DUE TO THE EXCRETION OF THAT GFP E. COLI BY THE CALVES OR IS IT
DUE TO THE CONTINUED SELECTION IN THE ENVIRONMENT. NEXT SLIDE PLEASE.
WHAT HE ALSO WANTED TO KNOW THEN WAS WHAT IS THE INFECTIOUS DOSE, IN THE SAME STUDY
WHAT HE WAS ABLE TO CALCULATE 50% OF CALVES WERE BEING COLONIZED AT 700 CELLS PER GRAM
OF BEDDING OR SOIL. SO NOW WE ACTUALLY HAVE A TARGET.
HE HAS A NUMBER HE CAN USE TO TRY TO FIGURE OUT HOW TO INTERVENE.
SO THIS LED TO THE STUDY HE’S CURRENTLY GOING. I NEED TO SPEED THIS UP.
WHERE HE’S LOOKED AT 14 DAIRIES ACROSS EASTERN WASHINGTON, LOOKED AT DIFFERENT SITES ON THE
DAIRY TO SEE WHERE THESE RESISTANT POPULATIONS ARE HIGH, WHERE THE E. COLI THAT ARE RESISTANT
TO DIFFERENT COMPOUNDS ARE LOCATED ON THE DAIRY AS POINTS OF INTERVENTION AND WHAT YOU’LL
SEE IS FOR THE CALVES IN HEIFER ENVIRONMENTS, THE NUMBERS WOULD BE HIGH TO COLONIZE THE
ANIMALS BUT THAT’S NOT WHERE THE ANTIBIOTIC IS BEING USED.
THAT MIGHT BE OVER IN THE HOSPITAL PENS, ON THE FAR RIGHT.
THERE MAY BE A DISCONNECT BETWEEN WHERE WE DECIDE TO HE CAN TO US INTERVENTION, IT WILL
ENVIRONMENTAL POINTS WHERE ANTIBIOTIC IS USED VERSUS HIGHLY ATRISK POPULATION LIKE CALVES
AND HEIFERS. HE’S USING THIS INFORMATION TO TRY TO DRIVE
WHERE TO DEVELOP INTERVENTIONS. NEXT SLIDE.
IN CONCLUSION I’LL QUICKLY GO THROUGH THESE. NOT ALL ANTIBIOTICS OR ADMINISTRATION PRACTICES
ARE GIVING THE SAME RISK, WHETHER IT’S ABOUT ANTIBIOTIC RESISTANCE OR EXCRETION.
WE NEED TO BE SMARTER ABOUT HOW WE EMPLOY IT, TO THINK ABOUT WHICH DRUGS, WHICH OF THE
DOSES ARE PROVIDING THE SELECTION PRESSURE AND MAKE OUR CHOICES ACCORDING THERE.
THERE SEEM TO BE ROBUST RESERVOIRS OF RESISTANT E. COLI THAT ARISE AFTER EXPOSURE TO EXCRETED
ANTIBIOTICS BUT THIS NEEDS MORE WORK. THE DENSITY OF RESISTANT BACTERIA IN THE ENVIRONMENT
IS OFTEN EXCEEDING THE AMOUNT THAT WOULD BE REQUIRED FOR COLONIZATION BUT NOT EQUAL ACROSS
THAT ENVIRONMENT SO TRYING TO DETERMINE THE HIGH RISK POINT BECOMES CRITICAL AND FINALLY
THE RESERVOIRS OF RESISTANT BACTERIA ARE AT PREDICTABLE LOCATIONS PERHAPS GIVING WAYS
TO TARGET MITIGATION STRATEGIES. OKAY.
THANKS, DOUG.>>WE WILL CONTINUE ON NOW WITH OUR THIRD
SPEAKER, THAT IS GOING TO BE DR. VIRGINIA STOCKWELL, PLANT PATHOLOGY AT USDA ARS, JOINING
US ON THE PHONE.>>YES, GOOD MORNING.
ARE THE SLIDES UP?>>YES, THEY ARE.
>>OKAY, GREAT. I CAN’T SEE THEM ON THE LIVE STREAM.
OKAY. SO GOOD MORNING.
THANK YOU FOR THE OPPORTUNITY TO TALK ABOUT ANTIBIOTIC USE ON CROPS.
I’LL TALK ABOUT WHICH ANTIBIOTICS ARE USED ON PLANTS, HOW AND WHICH PLANTS ARE TREATED,
SAFEGUARDS FOR I’M EXPOSURE AND IMPACT IN THE ENVIRONMENT.
SO FIRST OF ALL, THE U.S. ENVIRONMENTAL PROTECTION AGENCY REGULATES ALL PRODUCTS THAT ARE USED
ON PLANTS, CURRENTLY THREE ANTIBIOTICS ARE PERMITTED BY THE EPA, STREP MY SIN SINCE 1958,
OXYTETRACYCLINE, KOSUGAMYCIN, NO CLINICAL VALUE AND NO CROSS RESISTANCE.
ANTIBIOTICS ARE REGISTERED FOR SPECIFIC CROPS, MAINLY USED ON TREE FRUITS, APPLE, PEAR, PEACH
AND NECTARINE, NOT ON SEVERAL CROPS INCLUDING CORN, RICE, FIBERS LIKE COTTON, OTHER GRAINS
LIKE WHEAT, GRAPES OR BERRIES. SO ANTIBIOTICS ARE APPLIED IN THE ENVIRONMENT,
RESTRICTED MAINLY TO HIGH VALUE TREE FRUITS. NEXT SLIDE.
THIS SHOULD BE THE THIRD SLIDE AT THIS POINT. AN IMAGE OF TWO DISEASES THAT ACCOUNT FOR
MOST OF THE USE OF ANTIBIOTICS ON PLANS, TOLD USED FOR PLANT PROTECTION IS 36,000�KILOGRAMS,
OR ABOUT .25% OF THE TOTAL AMOUNT OF ANTIBIOTICS USED IN AGRICULTURE.
THE DISEASE ON THE LEFT IS BACTERIAL SPOT OF PEACH AND NECTARINE, THIS DISEASE CAUSES
DEFOLIATION OR LOSS OF LEAVES ON PEACH AND NECTARINE, UNSIGHTLY SPOTS ON THE FRUIT, GREATLY
REDUCING VALUE. THREE ANTIBIOTICS USED ON DROPS ONLY TETRACYCLINE
IS REGISTERED FOR BACTERIAL SPOT, USED PRIMARILY IN ORCHARDS IN HUMID SOUTHEAST U.S
THERE’S A LOT OF ACREAGE OF PEACH AND NECTARINE IN CALIFORNIA, GENERALLY NOT TREATED BECAUSE
THE CLIMATE IS TOO DRY FOR BACTERIAL SPOT. OVERALL ABOUT 15% OF THE QUANTITY OF ANTIBIOTICS
USED ON PLANTS IS APPLIED TO PEACH AND NECTARINE OR ABOUT 6�KILOGRAMS.
ON AVERAGE, GROWERS THAT USE OXYTETRACYCLINE APPLY THREE TIMES.
ALL THREE ARE REGISTERED FOR FIRE BLIGHT, USED INDIVIDUALLY OR IN COMBINATION OR ROTATION
TO MITIGATE RESISTANCE. THIS DISEASE IS CONSIDERED A FLORAL DISEASE
ACTUALLY. PATHOGEN COLONIZES FLOWERS, ENTERS THROUGHS
PORES AND KILLS THE FLOWER CLUSTER AS SHOWN ON THE UPPER LEFT PANEL.
THE DISEASE IS CALLED A BLIGHT BECAUSE THE PATHOGEN ENTERS THROUGH THE FLOWERS, RAPIDLY
INVADES THE STEM CAUSING DEATH. ANTIBIOTICS ARE INEFFECTIVE AFTER THE SYMPTOMS
ARE PRESENT. YOUNG TREES ARE PARTICULARLY SENSITIVE TO
FIRE BLIGHT, ON THE LOWER RIGHT IS APPLE ORCHARD IN MICHIGAN KILLED BY THE PATHOGEN.
PEAR TREES ARE MORE SENSITIVE THAN APPLE TREES, SO ANTIBIOTICS ARE USED IN A GREATER PERCENTAGE
OF PEAR ACREAGE THAN APPLE AND SPRAYED MORE FREQUENTLY ON PEAR.
FIRE BLIGHT IS DEVASTATING, IT’S SURPRISING TO ME MAJORITY OF ACRES ARE NOT SPRAYED AT
ALL. WHAT HAPPENS IS SOME GROWERS YOUR ALTERNATIVES
TO MANAGE FIRE BLIGHT, BUT OVERALL GENERALLY GROWERS USE DISEASE RISK MODELS TO DETERMINE
IF THEY NEED TO PROTECT ORCHARD WITH ANTIBIOTICS. BASICALLY IF TEMPERATURES ARE WARM DURING
BLOOM WHEN FLOWERS ARE OPEN, AND THERE’S A HISTORY OF FIRE BLIGHT IN THE ORCHARD RECENTLY,
MEANING THE PATHOGEN LIKELY IS PRESENT, THE GROWERS WILL INTERVENE WITH ANTIBIOTICS.
IF EACH ARE NOT MET THEY DON’T SPRAY. NEXT SLIDE.
THE EPA REGULATES DIRECT EXPOSURE OF WORKERS TO ANTIBIOTICS DURING AND AFTER SPRAYING ORCHARDS.
AND THIS IS REQUIRED ON THE LABELS, PROTECTIVE GEAR IS REQUIRED.
YOU CANNOT ENTER AN ORCHARD WITHIN 12 HOURS AFTER SPRAYING, WASH YOUR HANDS BEFORE DOING
OTHER ACTIVITIES, YOU HAVE TO SPRAY UNDER CONDITIONS THAT MINIMIZE POTENTIAL DRIFT AND
YOU CANNOT APPLY THE ANTIBIOTICS TO WATER OR CONTAMINATE WATER BY CLEANING OF EQUIPMENT.
WHAT HAPPENS TO ANTIBIOTICS WHEN SPRAYED INTO ORCHARDS?
NEXT SLIDE. THE ACTIVITY OF ANTIBIOTICS IS VERY SHORTLIVED
ON PLANT SURFACES. THEY SUPPRESS BACTERIAL GROWTH ON FLOWERS
FOR LESS THAN FIVE DAYS. THIS ACCOUNTS FOR REPEATED APPLICATIONS ESPECIALLY
IF BLOOM PROGRESSION IS CLUE. NUMEROUS FACTORS AFFECT LONGEVITY.
RAIN CAN REDUCE ANTIBIOTIC CONCENTRATION RAPIDLY ON PLANTS.
SUNLIGHT AND ULTRAVIOLET RADIATION CAN DEGRADE ANTIBIOTICS, AND AS SHOWN IN DR. CALL’S ON
SURFACES THEY CAN BE DEGRADED BY SOIL MIGHT BE ROBES.
THEY ARE ACTIVE ON PLANT SURFACES ONLY FOR A SHORT TIME.
THE QUESTION REMAINS DO THEY DISTURB MICROBIAL COMMUNITIES AND ENRICH FOR RESISTANCE GENES
IN ORCHARD ENVIRONMENTS. NEXT SLIDE.
SEVERAL STUDIES HAVE EXAMINED EFFECT OF STREPTOMYCIN. I DON’T HAVE TIME BUT IN THESE STUDIES MICROBIAL
COMMUNITIES OR PREVALENCE OF RESISTANT WERE COMPARED TO NONTREATED TREES.
ONE STUDY COMPARED ORCHARDS NEVER TREATED VERSUS ORCHARDS THAT HAD A TENYEAR HISTORY
OF ANNUAL TREATMENT WITH STREPTOMYCIN. SHORTTERM CHANGES IN MICROBIAL COMMUNITIES
WERE DETECTED BUT THERE’S NO LONGTERM EFFECT ON MICROBIAL COMMUNITIES.
LONGTERM MEANING LESS THAN A MONTH. IT’S NOT SURPRISING ACTUALLY GIVEN THAT ANTIBIOTIC
ACTIVITY HAS A SHORT DURATION ON PLANTS AND THESE ANTIBIOTICS ARE BEING APPLIED IN AN
OPEN ENVIRONMENT WHERE THERE’S AN INFLUX OF MICROBES THAT COULD RAPIDLY COLONIZE THE OPEN
NICHES THAT ARE PRESENT AFTER AN ANTIBIOTIC APPLICATION.
SO OVERALL, ANTIBIOTIC SPRAYS HAVE LITTLE IMPACT ON BACTERIAL COMMUNITIES IN ORCHARDS
AND APPARENTLY DO NOT INCREASE PREVALENCE OF ANTIBIOTIC RESISTANCE GENES IN THE ENVIRONMENT.
SO FINALLY LET’S EXAMINE CHEMICAL RESIDUES OF ANTIBIOTICS ON FRUITS.
NEXT SLIDE. THIS IS A CASE WHERE CONSUMERS COULD BE POTENTIALLY
DIRECTLY EXPOSED TO ANTIBIOTICS, AND WHAT HAPPENS IS THE EPA SPECIFIES THE PREHARVEST
INTERVAL FOR EACH ANTIBIOTIC OR HOW CLOSE TO A HARVEST AN ANTIBIOTIC CAN BE APPLIED.
SO FOR EXAMPLE STREPTOMYCIN ONE MONTH, KASUGAMYCIN THREE MONTHS.
SPRAYED IN
BLOOM ON FLOWERS AND KASUGAMYCIN IS GENERALLY STOPPED AT BLOOM.
THE PREHARVEST INTERVAL FOR STREPTOMYCIN OR TETRACYCLINE PERMITS PROTECTION OF YOUNG FRUITS
OR GREEN STEMS IF WOUNDED BY HAIL OR WIND STORM BUT GENERALLY BLOOM TIME SPRAYS.
THE EPA SETS MAXIMUM PERMISSIBLE RESIDUE ON FRUITS.
THERE’S NO REPORTS OF TREE FRUITS WITH ANTIBIOTIC RESIDUES EXCEEDING MAXIMUM LEVEL OF .35�MILLIGRAMS
PER KILOGRAM FRUIT. ONE STUDY HOWEVER APPLE TREES, SOPHISTICATED
CHEMICAL METHODS, APPLE TREES SPRAYED THREE TIMES, AT HARVEST HIGHEST DETECTION WAS 10FOLD
LESS THAN THE EPA PERMISSIBLE LEVEL. AND IN THAT STUDY MOST OF THE FRUIT HAD NO
DETECTABLE RESIDUES. SO THROUGH REGULATIONS CONSUMER EXPOSURE TO
ANTIBIOTICS WAS LIMITED. THE FINAL SLIDE, SO ANTIBIOTICS HAVE BEEN
USED FOR MORE THAN 60 YEARS IN PLANT AGRICULTURE WITHOUT DETECTED ADVERSE EFFECTS TO THE ENVIRONMENT
OR HUMAN HEALTH. THEY ARE IMPORTANT TOOLS FOR MANAGEMENT OF
BACTERIAL DISEASE OF TREE FRUITS, BECAUSE THEY ARE COST EFFECTIVE PROVIDE CONSISTENT
LEVELS OF DISEASE CONTROL AND THEY DON’T MAR FRUIT FINISH.
NOW, ALTERNATIVES ARE AVAILABLE BUT THE LEVEL OF DISEASE CONTROL CAN BE VARIABLE IN CERTAIN
ENVIRONMENTS AND SOMETIMES THE ALTERNATIVES CAN MAR FRUIT FINISH.
SO CONVENTIONAL GROWERS ARE HESITANT TO RELY WHOLLY ON THESE.
ORGANIC TREE ARE INCREASING IN ACREAGE. THE REAL WORLD EFFICACY OF ALTERNATIVES FOR
EFFECTIVE DISEASE CONTROL ON COMMERCIAL SCALE WILL BE TESTED IN ORGANIC ORCHARDS AND IF
METHODS ARE EFFECTIVE THEY MAY BE BE MORE WIDELY ADOPTED.
THE FOCUS WAS ON STREPTOMYCIN, ADDITIONAL RESEARCH IS NEEDED ON KASUGAMYCIN AND OTHERS.
THANK YOU VERY MUCH.>>THANK YOU.
WE HAVE 20 MINUTES FOR Q&A. DR. CALL IS NOT HERE.
IF THERE ARE QUESTIONS RELATED TO ANIMAL SIDE THOSE OF US ON THE COUNCIL WHO FEEL WE CAN
ANSWER ASSIST WITH THOSE QUESTIONS. LET’S START WITH DR. BLASER.
>>I’D LIKE TO COMPLIMENT ALL THREE PRESENTERS, EXTREMELY INFORMATIVE, CERTAINLY FOR ME.
I WANT TO ASK DR. STOCKWELL TWO QUESTIONS. THE FIRST, HAVE SURVEYS BEEN DONE ON FRUIT
IN THE SUPERMARKET OR AT THE FARM STAND TO LOOK AT NOT JUST RESIDUAL ANTIBIOTICS BUT
ANTIBIOTIC RESISTANT STRAINS OR GENES AND THE SECOND QUESTION IS HOW ABOUT THE IMPORTATION
OF FRUITS INTO THE UNITED STATES? WE IMPORT A LOT OF FRUITS FROM MANY OTHER
COUNTRIES. WHAT ARE THEIR PRACTICES, AND ARE STRAINS
IN GENES COMING THAT WAY?>>VERY GOOD QUESTIONS.
GENERALLY, OKAY, TO SUMMARIZE, GENERALLY FRUIT IN THE SUPERMARKET, AN UNWOUNDED FRUIT IS
VERY WAXY. AND WE GENERALLY DON’T GET MICROBES SURVIVING
ON THE WAXY SURFACE. YOU COULD GET SOME BACTERIA IN THE CALYX END
BUT IF THE FRUIT IS WOUNDED IN PROCESSING AND HANDLING AT THE SUPERMARKET LEVEL I GUESS
THERE COULD BE BACTERIA PRESENT. WE WORKED A LOT ON PEAR AND WE FIND THERE’S
VERY FEW BACTERIA AT ALL ON THE SURFACE OF THE FRUIT.
AS FAR AS RESISTANCE GENES, THEY ARE PRESENT IN THE ENVIRONMENT JUST NATURALLY, THERE’S
A LOT OF RESISTANCE. SOME JUST DUE TO SPONTANEOUS MUTATION, SOME
HAVE TRANSMISSIBLE GENES. IN THE ORCHARD ENVIRONMENT GENERALLY WE DO
NOT FIND HUMAN PATHOGENS UNLESS THE MAJOR ISSUE FOR FRUIT SAFETY IS POTENTIALLY USE
OF MANURES OR FECAL MATERIAL BY WILD ANIMALS AS SEEN WITH SPINACH PROBLEMS.
GENERALLY THE� ESSENTIALLY IF YOU GAVE ME AN APPLE OR PEAR AND SAID, WHAT KIND OF TREATMENT
WAS THIS FRUIT EXPOSED TO DURING PRODUCTION, I WOULDN’T BE ABLE TO TELL YOU IF IT WAS FROM
AN ORGANIC FARM OR AN ANTIBIOTICTREATED CONVENTIONAL FARM BECAUSE THE MICROBIAL COMMUNITIES WOULD
BE SIMILAR AND ANTIBIOTIC RESISTANT DETERMINANTS. THE POINT IS THE USE OF ANTIBIOTICS REALLY
ISN’T IMPACTING WHAT’S PRESENT AT HARVEST. AS FAR AS THE IMPORTATION OF FRUITS, THAT’S
AN INTERESTING QUESTION. GENERALLY IN EUROPE ANTIBIOTICS ARE EITHER
NOT PERMITTED OR HIGHLY RESTRICTED. IT’S DIFFICULT TO GET INFORMATION ON WHAT
IS GOING ON IN CHINA, AS FAR AS ANTIBIOTIC USE.
I’VE TRIED. AND I SEE SOME PAPERS THAT INDICATE ANTIBIOTIC
USE ON OTHER CROPS BUT NOT ON TREE FRUITS. AND GENERALLY WE DO NOT IMPORT FRUIT BUT WE
DO IMPORT THE PROCESSED MATERIALS. SO THAT IS SOMETHING THAT THERE ARE LIMITS
ON THE AMOUNT OF RESIDUES THAT CAN BE PRESENT IN IMPORTED MATERIALS BUT I HAVEN’T HEARD
OF ANYTHING BEING EXCESSIVELY USED. MEXICO DOES PERMIT STREPTOMYCIN AND OXY AND
GENTAMICIN. IT IS A DATA GAP.
>>AS YOU SAY, WE’RE IMPORTING A LOT OF FRUIT FROM MEXICO AND ALSO FROM OTHER PARTS OF CENTRAL
AND SOUTH AMERICA. ANY INDICATION OF THEIR PRACTICES OF SPRAYING
FOR ANTIBIOTICS OR HAVE ACTUAL SURVEYS BEEN DONE LOOKING AT FRUIT IMPORTED INTO THE UNITED
STATES?>>WELL, I WILL BACK UP AND SAY DOWN IN MEXICO
I DO KNOW THAT OXYTETRACYCLINE, STREPTOMYCIN AND GENTAMICIN ARE USED ON PEPPERS, TOMATOES
AND MORE CROPS THAT WE PERMIT IN THE STATES, AND I DO NOT KNOW OF ANYONE WHO HAS DONE A
CONCERTED SURVEY ON WHAT’S COMING IN ON THE FRUITS AND VEGETABLES.
>>THANK YOU. GREAT.
THANK YOU. NEXT WE’LL GO TO JOHN REX.
>>THANKS. THOSE WERE THREE REALLY GOOD TALKS.
TWO QUESTIONS, ONE FOR DR. CALL AND HIS GUISE AND DR. SINGER AND ONE FOR DR. GRAHAM.
DR. CALL, COUNTER INTUITIVE RESPONSE, CALLING IT HIGH AND LOW DOSE, MADE ME WONDER THE DEFINITION
OF HIGH AND LOW. I DID A VERY QUICK LOOKUP AND GIVEN TWO MGS/KG
OF THE DRUG, MAYBE A COUPLE TIMES A DAY, JUST BY ANALOGY TO OTHER THIRD GENERATION CEPHALOSPORINS,
I WOULD HAVE EXPECTED THAT DOSE TO BE 10 TO 30 MGS/KG RATHER THAN 2 MGS/KG.
COULD IT BE SOME IS DOSING AND HOW IS THE DOSING KNOWN TO BE CORRECT?
FOR DR. GRAHAM, REALLY INTERESTED TO THINK ABOUT HAVING 1 1/2 MILLION PEOPLE IN A SPACE
DESIGNED FOR 150,000. IS THERE TECHNOLOGY THAT ENABLE ALSO YOU TO
THINK ABOUT MANAGING HUMAN DISCHARGE, HUMAN WASTE, WITHOUT THE NEED TO BUILD LOTS OF INFRASTRUCTURE?
CAN WE APPLY TECH TO THIS PROBLEM TO MANAGE THIS ISSUE?
THAT’S THE QUESTION.>>I’M GOING TO LET DR. APLEY ADDRESS THE
FIRST QUESTION.>>SEPTOVIR IS AN EXAMPLE, 1.1 TO 2.2 MGS/KG
ONCE PER DAY, OR EVERY 48 HOURS, A SINGLE INJECTION VERSION, 6.6 MGS/KG, ON THE BROKE
POINT ON IN VITRO POTENCY, THAT’S OUR STANDARD THERAPEUTIC DOSE FOR BOVINE DISEASE AND FOOT
ROT, SOME OTHERS.>>I’LL SAY, AGAIN, REAL QUICK THE MICs, I
FOUND A TABLE SHOWING BLOOD LEVELS BARELY GET UP INTO THE SINGLE MICROGRAM PER MIL LEVEL
AT 24 HOURS AFTER THAT DOSE, FROM A HUMAN PK/PD PERSPECTIVE THAT LOOKS WRONG.
I DID NOT GO TO LIBRARYLAND. I LOOKED UP TWO PAPERS REALLY QUICKLY, AND
MY QUESTION WOULD BE JUST SORT OF MAYBE SOMETHING FOR US TO THINK ABOUT, DO WE KNOW WE’RE ACTUALLY�
WHEN WE USE IT SHOULD WE PERHAPS BE USING MORE?
THAT’S MY QUESTION.>>E. COLI IS NOT ON THE LABEL FOR IT AND
SO THE LABEL PATHOGENS, MIC 90, .03 TO .06 PER MIL, YEAH.
>>ACTUALLY THAT’S A REALLY GOOD QUESTION, THE TECHNOLOGY ISSUE, BECAUSE IT’S ONE OF
THE REAL THINGS THAT WE’RE WORKING ON NOW IS WHEN YOU’VE GOT 1.5�MILLION PEOPLE COMING
TO A SMALL STATE FOR A SHORT PERIOD OF TIME YOU CAN’T AFFORD TO BUILD WASTE TREATMENT
PLANT OR SOME TECHNOLOGY THAT’S GOING TO COVER THAT.
THE SOLUTION TO ADDRESS THAT IS THE SOLUTION IS REALLY A COMBINATION OF SOCIAL AND TECHNICAL,
AND YOUR ULTIMATE TECHNICAL SOLUTION MAY NOT BE THE PERFECT SOLUTION BUT IT WILL MAKE THINGS
A BIT BETTER. A SERIES OF ACTIONS ARE HAPPENING IN PLACES
LIKE THE AREA THAT WE’RE LOOKING AT. FIRST AS RATHER THAN TECHNOLOGICAL, THERE’S
A STRONG PUSH BY THE GOVERNMENT TO REDUCE AMOUNT OF OPEN DEFECATION.
YOU’VE GOT ALL THESE PEOPLE DEFECATING BECAUSE THERE’S NO PLACE TO GO TO THE BATHROOM BUT
THE PLAN NOW IS TO PLACE IN AT LEAST PORTABLE TOILETS.
THEY ARE THERE. I DON’T THINK IT’S ENOUGH.
IT’S AN EASY INVESTMENT, TOILETS THAT WILL DELAY THE TRANSMISSION OF RESISTANCE IN FECAL
MATTER TO THE RIVER OR TO OTHER PEOPLE IN CLOSE PROXIMITY.
WHAT WE REALLY ARE WORKING ON NOW, AND WE’RE NOT THE ONLY PEOPLE THAT ARE DOING IT IS LOOKING
AT VERY, VERY LOW ENERGY, LOW TECHNOLOGY WAYS OF REDUCING AND DELAYING TRANSMISSION.
IN THIS PARTICULAR CASE, TIME MATTERS. SO AFTER YOU DEFECATE, BASICALLY THE FRESH
FECAL MATTER IS ABOUT AS RICH AS IT CAN POSSIBLY BE IN THE TYPES OF THINGS YOU’RE CONCERNED
ABOUT, GENES AND BACTERIA. SO THE LONGER YOU CAN HAVE THOSE GENES AND
BACTERIA IN THE ENVIRONMENT BEFORE THE NEXT EXPOSURE, THE BETTER.
SO WE’RE PROMOTING VERY SIMPLE TECHNOLOGIES. I WAS TALKING THE OTHER NIGHT ABOUT TECHNOLOGY
THAT’S BASICALLY A PORTABLE TOILET WITH WORMS IN THE BOTTOM OF IT.
SO YOU BASICALLY DEFECATE ON THE WORMS, THE WORMS EAT THE FECAL MATTER AND REDUCE RESISTANCE
BASED ON THE WORM. I UNDERSTAND IT’S NOW BEING USED IN CHILE.
AND SO THAT’S ONE IDEA. BUT THERE’S A LOT OF OTHER OPTIONS.
WE’RE WORKING ON TECHNOLOGY THAT’S BASED ON SOLAR POWER.
SO WE’RE TRYING TO MAXIMIZE THE PROBABILITY. WE’RE NOT PUTTING IN WASTE TREATMENT PLANTS.
IT’S NOT ECONOMICAL AND IN LOCATIONS LIKE THE AREAS WE’RE LOOKING AT IT’S NOT JUSTIFIED
BECAUSE YOU’RE DEALING WITH A POPULATION OF A MILLION PEOPLE OVER A SHORT TIME.
SORT OF LIKE HAVING PEOPLE ATTEND A ROCK CONCERT SO THEY PUT IN TONS AND TONS OF TOILETS AND
IN THAT CASE THERE’S NOT AS MUCH PROBLEM RELATIVE TO BASAL LEVELS OF RESISTANCE BUT THE SOLUTION
ISN’T HIGH TECHNOLOGY AND THERE’S ACTUALLY A LOT OF DEBATE ABOUT THE BEST SOLUTION BUT
OURS IS TO TRY AND CREATE A CHANGE IN BEHAVIOR AND THEN PUT IN TECHNOLOGIES THAT DELAY CONTACT.
>>WE’LL KEEP MOVING. WE’VE GOT SEVERAL THAT WANT TO ASK QUESTIONS,
TRY TO LIMIT IT TO ONE QUESTION IF YOU CAN. NEXT WE’LL MOVE TO ALICIA COLE.
>>THANK YOU. THANK YOU ALL THREE PRESENTATIONS I THOUGHT
WERE WONDERFUL. I’D LIKE TO DIRECT MY QUESTION TO DR. GRAHAM.
I REALLY APPRECIATE YOU ASKING THAT WE START LOOKING AT WASTE WATER AS PART OF OUR CARB
ACTIONS HERE. WE’RE HAVING A PARTICULAR PROBLEM IN SOUTHERN
CALIFORNIA. 75 OF 100 OF OUR HOSPITALS IN SOUTHERN CALIFORNIA
HAVE HAD CRE, SIGNIFICANT CRE INFECTIONS, AND EACH DAY 2�MILLION�GALLONS OF HOSPITAL
RAW SEWAGE GOES JUST TO THE HYPERION WATER TREATMENT PLAN IN LOS ANGELES, CALIFORNIA.
THEN THAT TREATED SEWAGE IS PIPED FIVE MILES OUT INTO THE OCEAN.
NOW, AS A RESULT RECENT STUDIES SHOWED 689,000 TO 4�MILLION PEOPLE ARE STRUCK WITH GASTROINTESTINAL
ILLNESSES CAUGHT IN SOUTHERN CALIFORNIA BEACHES EACH YEAR AND ADDITIONAL 693,000 ARE SICKENED
WITH RESPIRATORY PROBLEMS. WE RECENTLY HAD TESTING AND FOUND THAT OUR
TREATMENT PLANTS ARE LOADED WITH ANTIBACTERIAL RESISTANT� MULTIDRUG RESISTANT ANTI BACTERIAL
PATHOGENS, CRE BEING A MAIN ONE, AND EPA SCIENTIST DR. JILL HOEL CAME TO DO SOME WORK AND I’VE
LEARNED SHE ALSO DID THE SAME KIND OF TESTING IN SEVEN DIFFERENT STATES AND IN EACH OF THOSE
STATES SHE FOUND THE SAME PROBLEMS WITH HOSPITAL SEWAGE IN OUR WASTEWATER.
AND SO I WOULD LIKE TO GET SOME OF YOUR RECOMMENDATIONS ON ACTIONABLE STEPS OR SOME COLLABORATIVE
EFFORTS THAT WE CAN START TO THINK ABOUT, EFFORTS JOINTLY AND ONE HEALTH PERSPECTIVE
WITH EPA AND CDC AND WHAT WE CAN DO HERE AT CARB.
THANK YOU.>>I CAN REALLY ONLY ANSWER IN GENERALITIES,
WE DON’T HAVE MUCH TIME.>>YES.
>>WHAT WE’VE BEEN PROMOTING AND WE’VE BEEN DOING THIS IN A NUMBER OF DIFFERENT COUNTRIES
IS SMALL SCALE WASTE TREATMENT PLANS IN THE HOSPITALS.
WE DON’T KNOW FOR SURE HOW BIG A CONTRIBUTOR HOSPITALS ARE RELATIVE TO ENVIRONMENTAL RESISTANCE
AND WE’VE GOT A VERY LARGE STUDY GOING ON IN DELHI RIGHT NOW DOING THIS AT A VERY LARGE
SCALE. AND WE STILL DON’T KNOW EXACTLY.
BECAUSE IT’S VERY HARD TO DETERMINE WHERE RESISTANCE COMES FROM ONCE IN THE ENVIRONMENT.
HOWEVER, THE GENERAL RULE IN ENVIRONMENTAL ENGINEERING IS TO TRY AND TREAT THE WASTE
IN ITS MOST CONCENTRATED FORM AT THE POINT OF GENERATION, IT’S MORE ECONOMICAL.
SO JUST FROM A PRACTICAL ENGINEERING CONTEXT THE TREATMENT SHOULD ACTUALLY HAPPEN AS CLOSE
TO THE POINT OF GENERATION AS POSSIBLE. NOW, THEN YOU GET TO THE DEBATE ABOUT WHAT
THE TECHNOLOGY SHOULD BE, AND A LOT OF THE TECHNOLOGIES WE USE AREN’T AS EFFECTIVE AS
THEY COULD BE. THEY ARE NOT TERRIBLE, THEY ARE PRETTY GOOD.
I KNOW TIM LaPara IS GOING TO TALK ABOUT THIS IN DETAIL LATER.
MY BROAD ADVICE IS TO THINK ABOUT TREATING THE WASTE IN THE MOST EFFECTIVE MANNER AS
CLOSE TO THE POINT OF GENERATION, BECAUSE IT WILL BE MORE ECONOMICAL, AND THEN YOU CAN
ACTUALLY CONTROL THE EFFLUENT MORE BECAUSE YOU CONTROL THE TECHNOLOGY.
ONCE THE WASTE GETS INTO THE SEWER SYSTEM IT GETS DILUTED.
AND THINK ABOUT MASS TRANSFER REACTION, ONCE IT GETS DILUTED ALL THE REACTION RATES WILL
BE SLOWER. SO THE SOONER YOU CAN TREAT IT, THE BETTER,
AND IT’S A CONCENTRATIONRELATED EFFECT.>>THANK YOU.
JAY BUTLER.>>THANK YOU.
DR. GRAHAM, YOUR COMMENT ABOUT INTERNATIONAL TRAVEL BY WILDLIFE INTRIGUED ME.
I WAS CURIOUS IF YOU’RE AWARE OF EVIDENCE ABOUT TRANSMISSION OF RESISTANT BACTERIA OR
RESISTANCE ELEMENTS VIA MIGRATORY WATER FOWL?>>WELL, I’M FAMILIAR WITH IT.
THEY FOUND BLONDEM1 THAT TRAVELED. ABOUT SIX MONTHS AGO THEY FOUND THE ORDER
OF 16,000�MILES AWAY THE GULLS HAD MOVED. I DIDN’T TALK ABOUT IT HERE BUT WE DO A LOT
OF WORK IN THE NORTH POLE, AND ONE OF OUR INTERESTS THERE IS LOOKING AT THE ABUNDANCE
OF DIFFERENT TYPES OF RESISTANCE IN AREAS WHERE THE WATERING LOCATIONS, THESE LOCATIONS
WHERE FUNCTIONALLY THERE’S NOTHING. YOU HAVE A SUMMER THAT LASTS A MONTH AND THEN
IT FREEZES UP FOR 11 MORE MONTHS. WE LOOK IN THESE AREAS WHERE THE WATER FOWL
ARRIVE AND WE SEE SOMETHING IN THE ORDER OF THREE TO FOUR HIGHER ORDERS OF MAGNITUDE OF
BLONDEM1 IN THE RESTING AREAS AND WATER AREAS. THERE’S NO POSSIBLE WAY THAT GENE COULD HAVE
GOT THERE ANY OTHER WAY THAN EITHER WATER FOWL OR ASSOCIATED WITH HUMANS AND HUMAN WASTE
THAT ARE RELEASED INTO THE ARCTIC ENVIRONMENT. SO THE TRICKY ONE I THINK IS A REALLY GOOD
QUESTION, BUT THE QUESTION THAT I THINK NOBODY KNOWS.
WE KNOW IT’S HAPPENING. WE DON’T KNOW HOW IMPORTANT IT IS.
AND WATER FOWL IN PARTICULAR ARE TARGET, THE GULLS, BUT THAT’S ALL I KNOW.
>>AS WE THINK ABOUT THE E. COLI SEQUENCE AND IT’S GLOBAL SPREAD HUMAN MIGRATION MAY
PLAY A PART BUT WHAT IS THE ROLE OF MIGRATORY BIRDS.
ONE MORE QUESTION.>>DR. STOCKWELL, ARE THEY MEASURED ON THE
SURFACE OF THE FRUIT, FLESH OF THE FRUIT, AND COULD THERE BE RESIDUAL IN THE FLESH IF
YOU’RE MEASURING THE SURFACE?>>GOOD QUESTION.
THEY HAVE GENERALLY� GENERALLY THEY GRIND THE FRUIT, THEY GENERALLY GRIND THE FRUIT
AND MEASURE THE AMOUNT OF ANTIBIOTIC. THERE HAVE BEEN STUDIES WHERE THEY LOOKED
AT DIFFERENT TISSUES, AND IT’S GENERALLY NOT IN THE FLESH.
WE CALL IT THE BUTT OF THE FRUIT, THE OLD FLOWER END ON THE BOTTOM.
THAT’S WHERE YOU MAINLY FIND RESIDUES BECAUSE AS THE FRUIT HANG DOWN THERE’S LESS WASH FROM
RAIN AND SEPALS SOMETIMES ENCLOSE THAT AREA, SO IF YOU COULD FIND RESIDUES THAT’S WHERE
THEY ARE GOING TO BE. THE FLESH IS ACTUALLY ALL NEW TISSUE, GENERALLY
SINCE AN ANTIBIOTIC WAS SPRAYED, SO GENERALLY WE DON’T EXPECT TO SEE ANTIBIOTICS IN THAT
TISSUE.>>SO JUST REAL QUICKLY I THINK WE HAVE TIME,
YEAH, RICH HAS ONE OF DR. STOCKWELL.>>THANK YOU FOR YOUR PRESENTATION.
A QUICK QUESTION, PART OF YOUR REGION, BUT DO YOU KNOW WHETHER ANTIBIOTICS ARE BEING
USED FOR CITRUS GREENING IN FLORIDA?>>I KNOW THAT� YES, THEY ARE RIGHT NOW.
THERE IS A PROPOSAL INTO THE EPA FOR AN EMERGENCY REGISTRATION TO USE ANTIBIOTIC FOR PREVENTION
OF CITRUS GREENING, AND MY UNDERSTANDING ACCORDING TO WHAT I’VE READ ON THE NEWS IS THAT THE
DEPARTMENT OF AGRICULTURE OF FLORIDA DECLARED AN EMERGENCY EXEMPTION WHICH MEANS THAT THEY
AT THIS POINT UNTIL THE EPA RULES THEY ARE PERMITTING ANTIBIOTIC USE ON CITRUS FOR PREVENTION
OF� WELL, FOR DEPRESSION OF CITRUS GREENING, A DIFFICULT DISEASE.
PERSONALLY I DON’T THINK ANTIBIOTICS WILL BE A LONGTERM SOLUTION FOR CITRUS GREENING,
BUT UNTIL YOU GET SOME OTHER METHODS I THINK ACTUALLY GMO IS PROBABLY GOING TO BE THE BREEDING
FOR RESISTANCE OR GENETIC ENGINEERING FOR RESISTANCE, THE ONLY WAY THEY ARE GOING TO
CONTROL THAT DISEASE. SO, YES, THERE IS.
IT’S NOT REGISTERED BY THE EPA, IT’S HARD TO SAY HOW THE EPA IS GOING TO RULE ON THE
USE OF ANTIBIOTICS ON CITRUS.>>I’D REALLY LIKE TO THANK OUR SPEAKERS.
THIS WAS A GREAT FIRST SESSION AND WE’RE GOING TO QUICKLY MOVE INTO OUR SECOND.
THAT’S GOING TO BE MODERATED BY DR. MARTY.

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