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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

Mean fold increase in abundance of tetracycline resistance genes (TetB, TetL, TetM, TetO, TetQ, and TetW) in PM collected immediately downwind of feed yards relative to samples collected upwind (n = 10/group). All six targeted tetracycline resistance genes were significantly more abundant in PM downwind of feed yards than upwind, with fold change values ranging from 100 to 1,000. Resistance gene TetM had the highest fold increase in abundance between PM collected downwind and upwind.*p < 0.002.
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f3: Mean fold increase in abundance of tetracycline resistance genes (TetB, TetL, TetM, TetO, TetQ, and TetW) in PM collected immediately downwind of feed yards relative to samples collected upwind (n = 10/group). All six targeted tetracycline resistance genes were significantly more abundant in PM downwind of feed yards than upwind, with fold change values ranging from 100 to 1,000. Resistance gene TetM had the highest fold increase in abundance between PM collected downwind and upwind.*p < 0.002.

Mentions: Abundance of antibiotic resistance genes. Abundances of six targeted tetracycline resistance genes were significantly (all p < 0.002) more abundant in PM collected downwind of feed yards compared with those collected upwind (Figure 3). TetQ and TetW were most prevalent across all feed yards (see Supplemental Material, Figure S7). We observed no significant correlation between tetracycline concentrations in PM and tetracycline resistance gene abundance.


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)

Mean fold increase in abundance of tetracycline resistance genes (TetB, TetL, TetM, TetO, TetQ, and TetW) in PM collected immediately downwind of feed yards relative to samples collected upwind (n = 10/group). All six targeted tetracycline resistance genes were significantly more abundant in PM downwind of feed yards than upwind, with fold change values ranging from 100 to 1,000. Resistance gene TetM had the highest fold increase in abundance between PM collected downwind and upwind.*p < 0.002.
© Copyright Policy - public-domain
Related In: Results  -  Collection

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

f3: Mean fold increase in abundance of tetracycline resistance genes (TetB, TetL, TetM, TetO, TetQ, and TetW) in PM collected immediately downwind of feed yards relative to samples collected upwind (n = 10/group). All six targeted tetracycline resistance genes were significantly more abundant in PM downwind of feed yards than upwind, with fold change values ranging from 100 to 1,000. Resistance gene TetM had the highest fold increase in abundance between PM collected downwind and upwind.*p < 0.002.
Mentions: Abundance of antibiotic resistance genes. Abundances of six targeted tetracycline resistance genes were significantly (all p < 0.002) more abundant in PM collected downwind of feed yards compared with those collected upwind (Figure 3). TetQ and TetW were most prevalent across all feed yards (see Supplemental Material, Figure S7). We observed no significant correlation between tetracycline concentrations in PM and tetracycline resistance gene abundance.

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