Limits...
Antibiotics, bacteria, and antibiotic resistance genes: aerial transport from cattle feed yards via particulate matter.

McEachran AD, Blackwell BR, Hanson JD, Wooten KJ, Mayer GD, Cox SB, Smith PN - Environ. Health Perspect. (2015)

Bottom Line: Airborne PM derived from feed yards facilitated dispersal of several veterinary antibiotics, as well as microbial communities containing ARG.Microbial communities of PM collected downwind of feed yards were enriched with ruminant-associated taxa and were distinct when compared to upwind PM assemblages.Furthermore, genes encoding resistance to tetracycline antibiotics were significantly more abundant in PM collected downwind of feed yards as compared to upwind.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Toxicology, Texas Tech University, Lubbock, Texas, USA.

ABSTRACT

Background: Emergence and spread of antibiotic resistance has become a global health threat and is often linked with overuse and misuse of clinical and veterinary chemotherapeutic agents. Modern industrial-scale animal feeding operations rely extensively on veterinary pharmaceuticals, including antibiotics, to augment animal growth. Following excretion, antibiotics are transported through the environment via runoff, leaching, and land application of manure; however, airborne transport from feed yards has not been characterized.

Objectives: The goal of this study was to determine the extent to which antibiotics, antibiotic resistance genes (ARG), and ruminant-associated microbes are aerially dispersed via particulate matter (PM) derived from large-scale beef cattle feed yards.

Methods: PM was collected downwind and upwind of 10 beef cattle feed yards. After extraction from PM, five veterinary antibiotics were quantified via high-performance liquid chromatography with tandem mass spectrometry, ARG were quantified via targeted quantitative polymerase chain reaction, and microbial community diversity was analyzed via 16S rRNA amplification and sequencing.

Results: Airborne PM derived from feed yards facilitated dispersal of several veterinary antibiotics, as well as microbial communities containing ARG. Concentrations of several antibiotics in airborne PM immediately downwind of feed yards ranged from 0.5 to 4.6 μg/g of PM. Microbial communities of PM collected downwind of feed yards were enriched with ruminant-associated taxa and were distinct when compared to upwind PM assemblages. Furthermore, genes encoding resistance to tetracycline antibiotics were significantly more abundant in PM collected downwind of feed yards as compared to upwind.

Conclusions: Wind-dispersed PM from feed yards harbors antibiotics, bacteria, and ARGs.

No MeSH data available.


Related in: MedlinePlus

Concentrations (ng/g PM) of five targeted veterinary antibiotics measured in PM collected immediately downwind of feed yards (n = 10). Abbreviations: CTC, chlortetracycline; MON, monensin; OTC, oxytetracycline; TC, tetracycline; TYL, tylosin. Individual data points represent concentrations from each feed yard. Boxes extend from the 25th to the 75th percentile, solid horizontal lines represent the median of each distribution, and dotted horizontal lines represent the mean. Numbers within the graph indicate the specific feed yard. Feed yard 4 had consistently elevated concentrations of antibiotics.
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4383574&req=5

f1: Concentrations (ng/g PM) of five targeted veterinary antibiotics measured in PM collected immediately downwind of feed yards (n = 10). Abbreviations: CTC, chlortetracycline; MON, monensin; OTC, oxytetracycline; TC, tetracycline; TYL, tylosin. Individual data points represent concentrations from each feed yard. Boxes extend from the 25th to the 75th percentile, solid horizontal lines represent the median of each distribution, and dotted horizontal lines represent the mean. Numbers within the graph indicate the specific feed yard. Feed yard 4 had consistently elevated concentrations of antibiotics.

Mentions: Three tetracycline antibiotics (tetracycline, chlortetracycline, and oxytetracycline) were detected together in most PM samples collected downwind of feed yards (60%); oxytetracycline was the most frequently detected of the three and was detected in 100% of PM samples collected downwind of feed yards. Mean concentrations were 280 ± 170 ng/g PM tetracycline, 820 ± 220 ng/g oxytetracycline, and 970 ± 430 ng/g chlortetracycline. In addition, oxytetracycline was detected in 30% of upwind samples at concentrations below the limit of quantitation. Overall, monensin was present at the highest concentrations in downwind PM, followed by chlortetracycline and oxytetracycline (Figure 1). One particular site, feed yard 4, had consistently elevated concentrations of all antibiotics compared with other feed yards.


Antibiotics, bacteria, and antibiotic resistance genes: aerial transport from cattle feed yards via particulate matter.

McEachran AD, Blackwell BR, Hanson JD, Wooten KJ, Mayer GD, Cox SB, Smith PN - Environ. Health Perspect. (2015)

Concentrations (ng/g PM) of five targeted veterinary antibiotics measured in PM collected immediately downwind of feed yards (n = 10). Abbreviations: CTC, chlortetracycline; MON, monensin; OTC, oxytetracycline; TC, tetracycline; TYL, tylosin. Individual data points represent concentrations from each feed yard. Boxes extend from the 25th to the 75th percentile, solid horizontal lines represent the median of each distribution, and dotted horizontal lines represent the mean. Numbers within the graph indicate the specific feed yard. Feed yard 4 had consistently elevated concentrations of antibiotics.
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4383574&req=5

f1: Concentrations (ng/g PM) of five targeted veterinary antibiotics measured in PM collected immediately downwind of feed yards (n = 10). Abbreviations: CTC, chlortetracycline; MON, monensin; OTC, oxytetracycline; TC, tetracycline; TYL, tylosin. Individual data points represent concentrations from each feed yard. Boxes extend from the 25th to the 75th percentile, solid horizontal lines represent the median of each distribution, and dotted horizontal lines represent the mean. Numbers within the graph indicate the specific feed yard. Feed yard 4 had consistently elevated concentrations of antibiotics.
Mentions: Three tetracycline antibiotics (tetracycline, chlortetracycline, and oxytetracycline) were detected together in most PM samples collected downwind of feed yards (60%); oxytetracycline was the most frequently detected of the three and was detected in 100% of PM samples collected downwind of feed yards. Mean concentrations were 280 ± 170 ng/g PM tetracycline, 820 ± 220 ng/g oxytetracycline, and 970 ± 430 ng/g chlortetracycline. In addition, oxytetracycline was detected in 30% of upwind samples at concentrations below the limit of quantitation. Overall, monensin was present at the highest concentrations in downwind PM, followed by chlortetracycline and oxytetracycline (Figure 1). One particular site, feed yard 4, had consistently elevated concentrations of all antibiotics compared with other feed yards.

Bottom Line: Airborne PM derived from feed yards facilitated dispersal of several veterinary antibiotics, as well as microbial communities containing ARG.Microbial communities of PM collected downwind of feed yards were enriched with ruminant-associated taxa and were distinct when compared to upwind PM assemblages.Furthermore, genes encoding resistance to tetracycline antibiotics were significantly more abundant in PM collected downwind of feed yards as compared to upwind.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Toxicology, Texas Tech University, Lubbock, Texas, USA.

ABSTRACT

Background: Emergence and spread of antibiotic resistance has become a global health threat and is often linked with overuse and misuse of clinical and veterinary chemotherapeutic agents. Modern industrial-scale animal feeding operations rely extensively on veterinary pharmaceuticals, including antibiotics, to augment animal growth. Following excretion, antibiotics are transported through the environment via runoff, leaching, and land application of manure; however, airborne transport from feed yards has not been characterized.

Objectives: The goal of this study was to determine the extent to which antibiotics, antibiotic resistance genes (ARG), and ruminant-associated microbes are aerially dispersed via particulate matter (PM) derived from large-scale beef cattle feed yards.

Methods: PM was collected downwind and upwind of 10 beef cattle feed yards. After extraction from PM, five veterinary antibiotics were quantified via high-performance liquid chromatography with tandem mass spectrometry, ARG were quantified via targeted quantitative polymerase chain reaction, and microbial community diversity was analyzed via 16S rRNA amplification and sequencing.

Results: Airborne PM derived from feed yards facilitated dispersal of several veterinary antibiotics, as well as microbial communities containing ARG. Concentrations of several antibiotics in airborne PM immediately downwind of feed yards ranged from 0.5 to 4.6 μg/g of PM. Microbial communities of PM collected downwind of feed yards were enriched with ruminant-associated taxa and were distinct when compared to upwind PM assemblages. Furthermore, genes encoding resistance to tetracycline antibiotics were significantly more abundant in PM collected downwind of feed yards as compared to upwind.

Conclusions: Wind-dispersed PM from feed yards harbors antibiotics, bacteria, and ARGs.

No MeSH data available.


Related in: MedlinePlus