# Presentation: 731245

## Veterinary Pharmaceuticals: Potential Environmental Impact and Treatment Strategies

-                         **presented at the**
-      **Emerging Pollutants Workshop**
-                             **hosted by**
**           ****US EPA  Region  5**
-      John L. Cicmanec, DVM, MS, ACLAM
-         NRMRL, US EPA, Cincinnati, OH

## Acknowledgements

- Dr. Craig Adams, Univ. of Missouri-Rolla
- Dr. Lars Angenent, Washington Univ.
- Dr. Thorsen Christian, University of Bonn
- Dr. Thomas Heberer, Technical Univ. Berlin
- Dr. Barry Hooberman, FDA
- Kenneth Loftin, Univ.of Missouri-Rolla
- Dr. David Sedlak, Univ. California, Berkeley
- Zhimin Qiang, Univ. of Missouri-Rolla

## A Beef Cattle CAFO Operation

**Notes:**
Point Sources and Non Point Sources

Human Sewage - onsite systems; wastewater treatment plants - effluent

Grazing domestic and wild animals

Application of wastewater treatment plant effluent; treated sludge; animal manure.

Wet Weather Flows - CSOs; SSOs; +

Confined Animal Feeding Operations
Much greater quantities of wastes produced compared to humans.  Pathogen densities are 10 to 100 times greater.

## A Typical Poultry CAFO Operation

**Notes:**
Point Sources and Non Point Sources

Human Sewage - onsite systems; wastewater treatment plants - effluent

Grazing domestic and wild animals

Application of wastewater treatment plant effluent; treated sludge; animal manure.

Wet Weather Flows - CSOs; SSOs; +

Confined Animal Feeding Operations
Much greater quantities of wastes produced compared to humans.  Pathogen densities are 10 to 100 times greater.

## Groups of Compounds

- Antibiotics
- Anthelmintics
- Hormones; steroids and bovine ST
- Pesticides
- Vaccines
- X-Ray contrast media, iodine & barium based

## Potential Endocrine Disrupting Chemicals

- Trenbolone acetate (Revalor**R****, **Finiplex**R**)
- Melengestrol acetate
- Estradiol benzoate
- Ractopamine (Prolean**R**)
- Testosterone proprionate
- Human chorionic gonadotropin
- Prostaglandins

## Trenbolone & Melengestrol

**Little is known about their fate after excretion by the animal**
**Trenbolone half-life when stored as liquid manure is **_**267 days**_
**In farm field studies ****Trenbolone**** was detected at the end of fertilization period and ****Melengestrol **** was detected at harvest**

## Where Does RactopamineFit In?

****** ****adrenergic agonist;**
**Partitions energy from fat growth to lean growth;**
**Increases protein accretion and muscle growth;**
**Increases muscle fiber diameter**

## Impacts of Improved Feed Efficiency

**RAC -fed pigs require less feed for equivalent lean gain (12.7%)**
**Fewer natural resources are needed for crop production for the swine industry when utilizing RAC (Carroll, et al., 2001).**
**RAC-fed pigs take 4 less days to a constant market weight.**

## Swine Units

_**Gestation building**_
_**Growth/Finishing**_**  **_**buildings**_

## Hog Heaven

## Humans and Farm Animal Waste as a Source of Steroid Hormones

|  | Estradiol (ppb) | Testosterone (ppb) |
| --- | --- | --- |
| Cattle | 19 ± 3.5 | n.d. |
| Swine | 152 ± 2.4 | 21 ± 18 |
| Municipal | 31 ± 5.4 | 29 ± 7.3 |

***Humans and Farm Animal Waste as a Source of Steroid Hormones***

## Categories of Antibiotics 

**Sulfonamides –    sulfamethoxazole, etc**
**Quinolones-         Ciprofloxacin**
**Beta-lactams-       penicillins,             **
**                               ****cephalosporins**
**Aminoglycosides- streptomycin, **
**                                ****gentamycin**
**Macrolides –         erythromycin, tylosin**

## Injectable Form of 2 Antibiotics

## Relative Antibiotic Use for Animals & Humans

_**Europe**_
**3902 tons used for farm animals; 7000 tons used for humans (1998)**
**Europe’s human population is 390 million people**
**Cattle –   19.8 million**
**Swine -     8.8 million**
**Sheep -     6.4 million**
**Poultry -    1  **_** billion**_** **

_**United**_** **_**States**_
**15,100 tons used for farm animals; 4800 tons used for humans (1997)**
**USA human population is 270 million people**
**Cattle -   97 million**
**Swine –  59 million**
**Sheep –   7.8 million**
**Poultry – **_**1.8 billion**_

## Relative Antibiotic Use Humans & Animals (continued)

- * In Europe the ratio is _7:4 in favor of humans_
- Because of relatively low animal populations
- In the United States the ratio is _15:5 in favor of_ _animals_ because of larger animal numbers
- Note: For all animal populations an adjustment was made for body size –
-                                              4 pigs =  1 cow
-                                  100 chickens  =  1 cow

## Use of Antibiotics as Growth Promoters in Europe

**In 1997, before controls, annual use was **_**1599 tons**_** (separate from treatment of microbial diseases)**
**In 1999, after controls were introduced the annual use dropped to **_**786 tons**_

## Animal Antibiotics in the Environment

- Presently in Europe only 4 antibiotics - monensin, avilamycin, flavomycin, & salinomycin are approved for animal use
- Primarily the macrolides & sulfonamides persist in the environment
- Tetracyclines, penicillins & fluoroquinolones rapidly degrade
- Concentrations found-usual 1-5 ng/L but can range up to 300 ng/L

## Tylosin as a feed-additive for swine

-  macrolide antibiotic
-  Tylan by Eli Lilly & Co
-  20 g / ton dry feed
-  mechanism and resistance similar to lincosamide 	and streptogramin B type

## Slide 20

## Anaerobic degradation of Tylosin

**Swine waste: **
**  ****1.6 mg/liter tylosin +  dehydroxi-tylonolide (breakdown product)**
** ****Digester (effluent): always <0.26 mg/liter + often breakdown product**
** ****Result - tylosin degradation, no performance loss**

## Solution

- Full-scale ASBR Nevada, IACrawford Swine Farm: 2800 head

## .

## Results of Screening Study -Lincomycin -10 mg/L (α=0.05)

## Results of Screening StudyTylosin Tartrate -10 mg/L (α=0.05)

## Slide 26

## Species Comparisons of Resistance in E. coli

**Notes:**
Animal isolates exhibit a much higher prevalence of tetracycline resistance than human isolates
The patterns observed among the resident geese (who have access to lagoons and feed) are very similar to those observed among the swine isolates
Human isolates exhibit a higher prevalence of trimethoprim and florfenicol resistance than animal isolates

## E. coli Resistance in Surface Waters

**Notes:**
The higher prevalence of streptomycin and tetracycline resistance observed in surface waters downstream from swine AFOs suggests off-farm transport of resistance patterns
The predominant resistance patterns observed in downstream E. coli are also among clinical isolates reported by NARMS

## Enterococcus Resistance among Waste Sources

**Enterococcus Resistance among Waste Sources**

## Emerging pathogen-recognized in 1985
Multiple antibiotic resistance-ampicillin, chloramphenicol, tetracycline, streptomycin, & sulfonamides
Watery diarrhea & loss of condition-40% mortality in affected cattle
Can affect many other mammals and birds

- Multiple **antibiotic resistance**-ampicillin, chloramphenicol, tetracycline, streptomycin, & sulfonamides
- Watery diarrhea & loss of condition-40% mortality in affected cattle
- Can affect many other mammals and birds

***Salmonella typhimurium**** *Phage-type DT 104

## Generic Conceptual Models

- Resistant
- Pathogen

- Contamination of Food Supply

- AR Disease: Food-borne Illness

- Resistant
- Commensal

- Contamination of Food Supply

- AR Disease: Opportunistic AR Infection

- Human AR Carriers

*Human Populations*

*Food Animals*

- Relapsed
- AR Disease

- Food-borne Illness

**Pathogenic Bacteria**

**Commensal Bacteria**

## Antibiotic Resistance on the Farm

**Bacterial samples were collected from animals, bedding, transport cages**
**Chickens: ~60% have resistance streptogramin-resistant E.faecium (SREF)**
**Some geographical variation but present at all sites tested**

## European and U. S. Data

**Resistance in Retail Meat**
**Poultry: 30 - 60% have SREF**
**Also present in Pork and Beef products**
**Incidence among Humans**
**US: 0.4 - 1% have SREF**
**Europe: up to ~10% reported**

## Linking Animal & Human Use

- Animal Drug - Virginiamycin
- Streptogramin (Group B)
- Used in animals for > 26 years
- Used as growth promoter at sub-therapeutic levels
- Human Drug - Synercid
- Streptogramin - Quinupristin/Dalfopristin combination
- Approved for therapy in US (1999)
- Active against Gram-positive bacteria  - “drug of last resort”

## Danish Study

## Effect of Antibiotics on Field Crops (Jjemba)

**Pharmaceuticals such as chlorotetracycline, metronidazole, and sulfamethoxine are ****toxic to plants**** such as soybeans, poinsettia, and corn at concentrations of 10-160 ppm **

**Notes:**
Identify possible sources of pathogens
	grazing animals
	homes/ people
	park / camps

## Processes to Remove Pharmaceuticals

**Sorption to particles**
**Ultraviolet light**
**Bacterial degradation**
**Reverse osmosis**
**Others**

## Occurrence of Pharmaceuticals in Surface Water and Ground Water in Germany (Heberer, 2001)

- _Compound_       _Surface_ μg/L      _Ground_ μg/L
- Clofibric acid             4.6                     0.7
- Diclofenac                 3.0                     0.3
- Ibuprofen                   0.8                     0.2
- Salicylic acid              3.4                    1.2

## Occurrence of Pharmaceuticals in Wastewater (U.S.)

-  _**Compound   **_   _** Concentration    **_    _**Excretion**_
**Acetominophen   61 ug/L             conjugates**
**Ibuprofen              37 ug/L            conjugates**
**Amoxicillin           27 ug/L            original form**
**Cephalexin           14 ug/L            original form**
**Penicillin                 4 ug/L            original form**
**Gemfibrozil             3 ug/L            original form**
**Ranitidine               3 ug/L          no information**

## Sorption Data for Selected VPs

- _Compound_        log _K__**ow**__** **_**         **_** **__pK__**a**__ _
- Tetracycline         -1.19         3.3, 7.7, 9.7
- Cipro                     0.4            5.9, 8.9
- Avermectin            3.19
- Tylosin                   3.5           7.1
- Sulfamethazine     0.89          2.6, 7.6
- Metronidazole       0.02          2.4
- Chloramphenicol   1.14

## Ceftiofur (NaxcelR)

**Approved by FDA for treating respiratory disease in cattle with **_**no**_** withholding time for milk**
***Bacillus stearothermophilus ***** test will detect levels of 50 ppb in milk; but when used according to directions none is detected in the milk**

## What we can Learn from Studies of Human Pharmaceuticals

**Most persistent drugs are ****diazepam, carbamazepine, bezafibrate,& iopromide**
- Elimination from wastewater depends primarily upon _sludge retention time_
- For activated sludge systems _4-5 days_ are needed; for nitrogen removal _8-20 days_

## Summary

- Presently antibiotic-resistance and Endocrine Disrupting Chemicals have been shown to have the greatest potential for causing environmental damage
- The vast quantities of compounds  and wide-spread distribution make Veterinary Pharmaceuticals a significant environmental challenge
- Product control and distribution is more complex than for Human Pharmaceuticals