1、Antibiotics in the Environment.,Erik J. Rosenfeldt, PhD, PE Assistant Professor University of Massachusetts, Amherst Department of Civil and Environmental Engineering,Me,BS in Chemical Engineering Washington University in St. Louis, MO MS in Civil and Environmental Engineering Duke University, Durha
2、m, NC Thesis: Destruction of Endocrine Disrupting Compounds in Water with Direct UV and UV/H2O2 Advanced Oxidation. PhD in Civil and Environmental Engineering Duke University, Durham, NC Dissertation: UV and UV/H2O2 Advanced Oxidation A theoretical, practical, and comparative examination of UV proce
3、sses used to treat emerging contaminants of concern in drinking water.,Research Interests,Mitigating threats from Endocrine Disrupting Chemicals (EDCs), Pharmaceuticals and Personal Care Products (PPCPs) in drinking water, wastewater, and reuse water, by combining novel adsorption methods and advanc
4、ed oxidation processes. Quantifying advanced oxidation potential in drinking water, wastewater, and reuse water. UV AOP and alternative oxidation technologies for direct potable reuse applications. Evaluate strong oxidizing processes to replace traditionally energy intensive regeneration methods for
5、 spent zeolite adsorption media. Assess the ability of several natural zeolite products for removal of water contaminants Assessing distribution system microbial quality utilizing flow cytometry methods,More about Me,Hobbies include running, hiking, basketball, playing with my wife daughter, son and
6、 dog,Todays Agenda,8:45 9:00 Introduction 9:00 10:30 Antibiotics in the environment 9:00 9:45: Analyzing for antibiotics in water (presentation) 9:45 10:30: Setting up the lab portion of the course 10:30: Samples need to be incubating (need 2 hours) 10:30 10:45 Break 10:45 11:45 Issues with Emerging
7、 Contaminants in Water (presentation) 11:45 12:00 Break 12:00 1:00 Data analysis and discussion Take pictures of samples, process pictures Data Analysis Discussion,Analyzing for Antibiotics in Water,Erik Rosenfeldt, PhD, PE Assistant Professor University of Massachusetts, Amherst,The story begins,Pe
8、nicillin 1928 Alexander Flemming found antimicrobial properties of substance exuded from Penicillium notatum (mold) “might have therapeutic value if it could be produced in quantity.”,The story now,100,000 200,000 tons of antibiotics used worldwide US Production = 22.7 million kilograms In US, 70% o
9、f dispensed antibiotics are given to healthy livestock to prevent infections and/or promote growth This practice is outlawed in EU countries,Categories of Antibiotics,Antibiotics in the Environment,Human Inputs,Excretion of therapeutic antibiotics and metabolites Many discreted directly in amounts 4
10、0% of ingested dose Disposal of unused antibiotics Flushing down the toilet Washing topically applied antibiotics All go to septic systems or municipal WWTPs Inefficient removal Breeding grounds for antibiotic resistant organisms (ARO),Veterinary Inputs,Antibiotics used in livestock operations since
11、 the early 1950s Used to treat infections, or to improve growth and feed efficiency Four “types” of AB use in livestock operations Therapy: Antibiotics for treatment of frank clinical disease Control: Antibiotics administered to a herd or flock in which morbidity and/or mortality has exceeded baseli
12、ne norms Prevention: Antibiotics used in animals considered “at risk”, but where individuals do not show signs of disease Growth Promotion: Antibiotics administered over a period of time, usually as a feed additive, to growing animals,Veterinary Impacts,Antibiotics impact aquatic environment through
13、 manure Large fraction of the medicines present unchanged in animal waste Direct runoff or collection and use as fertilizer,Impacts Human health concern?,Found at 1 ng/L 1 ug/L levels in environment Typical therapeutic doses = 100 250 mg per dose (3x per day?)Need to drinkNot likely an issue,Impacts
14、 Microbial Resistance?,Environmental levels have been found to enhance the ability of microorganisms to develop antibiotic resistance Onan and Lapara (2003), FEMS Microbiology Letters 220: 15 20 Evidence of antibiotic resistant microorganisms has been found in surface wastewater, groundwater, drinki
15、ng water. Schwartz et al. (2003), FEMS Microbiology Ecology 43, 325 - 335,Revisit human health concerns?,MRSA (Methicillin Resistant Staphylococcus aureus) Very difficult to treat First appeared as hospital derived infection 1990s Community associate outbreaks among high risk populations Today, colo
16、nization rates in general population 1.5% Infections account for majority of skin and soft tissue infections treated in US Emergency Rooms. In 2005, MRSA caused more deaths in US than AIDS,Antibiotic Resistance as a human health concern,Enteric pathogens such as Salmonella and EHEC (Enterohaemorrhag
17、ic Escherichia coli) causing illness and treatment failure Other multi-drug resistant organisms: Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa. Relatively few pathogens in nature, but Antibiotic resistance is transferable!,How to detect antibiotics in water?,Very sensitive,
18、low level detection available through GC/MS/MS and LC/MS/MS Example Minimum Reporting Limits (MRLs): Cyprofloxacin: 20 ng/L Erythromycin: 50 ng/L Sulfamethoxazole: 0.25 ng/L Trimethoprim: 140 ng/L Approximately $500 - $700 quoted per sample!,What if we could detect overall “antibiotic activity”,Adva
19、ntages: Much cheaper ($1 per sample) Faster (may get results in a few hours, instead of weeks) Dont have to ship samples Anyone can do it! Activity might be the only thing that matters Questions? Do we really care which antibiotics are in solution? Different antibiotics act on different parts of the
20、 microbe cell Different antibiotics possess different “strength” Are there other “antimicrobial agents” in solution?,Antibiotic Activity,We look at other compounds through “activity”,Yeast Estrogen Screen (YES),YES,Advantages: Cheap ($1 per sample) Fast (Get results in a few days, instead of weeks)
21、Easy for a grad student to do. Activity might be the only thing that matters (Rosenfeldt et al, 2007) Questions: Do we really care about which EDCs are in solution? Synergistic / Competitive effects?,YES Outputs,YES Calibration Curves,My Research Question,Is it possible to make a YES-style assay for
22、 the detection of Antibiotics in water? “Inexpensive” Rapid and convenient Give us good information for occurrence and treatment studies?,The Antibiotic Challenge (ABC) Assay,Smith et al, 2007 “The development of a rapid screening technique to measure antibiotic activity in effluents and surface wat
23、er samples” Utilized the fact that the meat and dairy industry regularly (in EU) and semi-regularly (in US) tests for antibiotic residues. Commercially available kits have been created to ease this process for meat and dairy producers (ie farmers, not cows),Smith et al, 2007,Utilized the Premitest,
24、from DSM food industries (Netherlands) Designed to test meat for the presence of antibiotics Made slight modifications to test water samples Add a little “synthetic meat” Extract and concentrate samples,How does the Premitest work?,Uses a rapidly growing, thermophilic bacteria as the indicator Bacil
25、lus stearothermophilus Responsive to all of the most commonly used antibiotics (ie easy to kill) Provides a measurable color change in the agar substrate when not exposed to antibiotics As Bacillus grow, they release acid products Acid makes color change (just like pH indicators) If Bacillus growth
26、inhibited, less grow, less acid, less color change,Smith et al, 2007 (cont),Identified a qualitative “calibration curve”,Smith et al, 2007 (cont.),Calibration curves Surface Water Samples,Other similar antibiotic activity assays,Our Procedure,“Delvotest P-Mini” Sensitive to many antibiotics Initial
27、kit comes with several boxes worth of tests along with a block heater for $100. Cost of 25 ampules = $30 - $35 Color Change takes 2 2.5 hours Advantages over Premitest Initial tests indicate no additional materials needed Comes with “nutrient pellets”,Procedure,Step 1: Preparation Cut off the requir
28、ed number of ampoules with a pair of scissors. Be careful not to damage the foil of the remaining ampoules. Step 2: Open the seal Open ampoule(s) by punching a hole in the aluminum foil with the syringe. Mark the ampoules for sample identification. Step 3: Take a milk water sample Attach a new dispo
29、sable pipette to the syringe. Depress the plunger completely, dip the tip in the milk sample and allow the plunger to return slowly under pressure of the spring.,Procedure,Step 4: Inoculation Empty the syringe into the correspondingly marked ampoule by slowly depressing the plunger of the syringe. U
30、se a fresh disposable pipette for each sample. Step 5: Incubation Check the temperature of the incubator (64C 0.5C). Put the ampoule(s) into the incubator. Record the time and set timer for 3 hours or use control time. Step 6: Results After 3 hours, remove the samples from the incubator. Read the co
31、lour of the lower 2/3 part of the solid agar in the ampoule(s) after the required incubation time.,Data Analysis,Collect digital image of the vials Digital Photo Image Scanner Create .pdf file Analyse image for color using “colors.exe” http:/ Otaka I, Kumagai K, Inagaki Y, Shimoyama M, Saegusa K, Ha
32、ra T (2002) Simple and inexpensive software designed for the evaluation of color American Journal of Ophthalmology 133 (1): 140 142. Vector Analysis to quantify response,Digital Images,Positive Control,Negative Control,“Real Images”,Full Test (Amoxicillin in DI water)Images of groups of vials,0.5, 1
33、, 1 and 4 g/L,6, 8, 10 and 20 g/L,Positive control,Data Analysis,Data Analysis,Trim the image and analyze the R, G, B contribution of the average image ie, R = 0.74, G = 0.59, B = 0.63,Data Analysis,Create a “3-D” plot of the data point, with Red, Green, Blue as the axes Vector Analysis to analyze d
34、istance from Negative Control to the Data Point (Segment 1) Data Point to Positive Control (Segment 2),Data Analysis,Comparison of Response curve of Pennicillin dissolved in lab water and Quabbin water,Very minimal interference in “pristine, natural water”,Todays Experiment,3 groups 1 group will be
35、creating a calibration curve Positive (50 mg/L Penicillin), Negative (0 Penicillin) 100, 250, 400, 500, 700, 1000 ng/L 1 group will investigate potentially negative activity impact of synthetic estrogen Positive (50 mg/L Penicillin), Negative (0 Penicillin) 1000 ng/L Penicillin + 50, 100, 250, 500,
36、1000, 2000 ng/L EE2) 1 group will investigate potential false positives (H2O2) Positive (50 mg/L Penicillin), Negative (0 Penicillin) 0 ng/L Penicillin + 2, 5, 10, 50, 100, 250 mg/L H2O2,Hypotheses?,Addition of a compound with unrelated activity can negatively impact activity of an antibiotic Addition of an inorganic antimicrobial agent (H2O2) will not interfere with assay at “low” concentrations Optimistic?,
