John H. Loughrin

United States Department of Agriculture

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Nanh Lovanh

Agricultural Research Service

Thomas R. Hamilton–Kemp

University of Kentucky

Roger A. Andersen

Ondine (Canada)

K. R. Sistani

Agricultural Research Service

Matías B. Vanotti

Agricultural Research Service

Rezaul Mahmood

University of Nebraska–Lincoln

David F. Hildebrand

University of Kentucky

Ariel A. Szögi

Agricultural Research Service

Kimberly Cook

Agricultural Research Service

Getahun E. Agga

Agricultural Research Service

Cooperative Institutions

Agricultural Research Service

United States Department of Agriculture

Technological Institute of Castilla y León

Universitat Politècnica de Catalunya

Universitat de Miguel Hernández d'Elx

Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement

Consejo Superior de Investigaciones Científicas

University of Kentucky

Western Kentucky University

Kentucky State University

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Effect of Continuous In-Feed Administration of Tylosin to Feedlot Cattle on Antimicrobial Resistant Enterococci Using a Randomized Field Trial

Getahun E. Agga Hunter O. Galloway Keerthi Appala Faranak Mahmoudi John Kasumba

Liver abscess causes substantial economic loss to the beef cattle industry through liver condemnation, reduced animal performance, and carcass yield. Continuous in-feed use of tylosin is the most effective and a commonly used practice in beef cattle production to prevent liver abscess. However, such mass medication can increase the level of antimicrobial resistant bacteria. We investigated the effect of continuous in-feed use of tylosin in feedlot cattle on (i) concentrations and prevalence of erythromycin-resistant (ERYr) and tetracycline-resistant (TETr) enterococci; (ii) associated antimicrobial resistance genes (ARGs) for resistance; (iii) species distribution; iv) macrolide and tetracycline resistance gene concentrations; and (v) tylosin concentration.A cohort of weaned calves were randomized to receive tylosin-medicated feed (Tylosin; n=10) or nonmedicated feed (Control; n=10) for a full feedlot cycle. Feces, feed and pen-surface samples were collected and processed by culture, droplet digital PCR, and liquid chromatography/mass spectroscopy for bacterial enumeration, detection and characterization, ARG quantification, and tylosin concentration, respectively. Data were analyzed by multilevel linear- or binary-regression models depending on the outcomes.Tylosin administration significantly increased fecal concentration (P<0.001) and prevalence (P=0.021) of ERYr enterococci and ermB gene concentration (P<0.001), compared to the control group. Interestingly, tylosin administration significantly reduced (P=0.037) fecal TETr enterococci concentration compared to the control group, with no significant effect (P=0.758) on fecal tetM concentration. In both treatment groups, enterococci concentrations increased over time, peaking on 174 days in feed before returning to the baseline. ERYr enterococci concentration was significantly (P=0.012) higher in tylosin medicated feeds, with no significant effect (P=0.321) on TETr enterococci concentration. Pen-surface concentration of ermB was significantly (P=0.024) higher in the tylosin group, with no significant effect (P>0.05) on bacterial concentrations. Increased diversity and a shift in the composition of enterococcal species and ARGs were observed over time, although tylosin use did not significantly affect (P>0.05) their prevalence. Tylosin concentration was significantly higher (P<0.001) in the feces of tylosin administered cattle and medicated feed (P=0.027), with numerically higher pen-surface concentration (P=0.065) in the tylosin group.In conclusion, continuous in-feed use of tylosin in feedlot cattle increases macrolide resistant enterococci and its fecal excretion, while decreasing tetracycline resistance. Two medically important species, E. faecium and E. faecalis, were predominant regardless of resistance status or sample source. Risk-based approaches including label changes to limit tylosin use such as withdrawal period, and development of effective manure treatments are potential areas of research to reduce environmental and public health impacts.

Tylosin

Feedlot

Field trial

10.2139/ssrn.4333079

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Citations (1)

A Gas Chromatographic Method for the Determination of Bicarbonate and Dissolved Gases

Frontiers in Environmental Science (2017)

John H. Loughrin Stacy W. Antle Jason Polk

A gas chromatographic method for the rapid determination of aqueous carbon dioxide and its speciation into solvated carbon dioxide and bicarbonate is presented. One-half mL samples are injected through a rubber septum into 20-mL vials that are filled with 9.5 mL of 0.1 N HCl. A one mL portion of the headspace is withdrawn and injected onto a gas chromatograph equipped with a thermal conductivity detector. Using the dimensionless Henry's constant for carbon dioxide and an adaptation of the Henderson-Hasselbalch equation, carbon dioxide in the samples can be categorized among solvated, bicarbonate, and carbonate forms. Natural water samples as well as wastewater from a municipal sewage treatment plant and a swine rearing operation were analyzed by this method and the results compared favorably to those obtained by titration. Samples stored for up to five weeks showed no significant changes in carbon dioxide concentrations. In addition, using flame ionization and electron capture detectors, methane and nitrous oxide concentrations in the samples were also measured.

Bicarbonate

Flame ionization detector

10.3389/fenvs.2017.00065

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Spatial and temporal changes in the microbial community in an anaerobic swine waste treatment lagoon

Anaerobe (2009)

Kimberly Cook Michael J. Rothrock Nanh Lovanh John K. Sorrell John H. Loughrin

Biogas

10.1016/j.anaerobe.2009.06.003

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Recirculating Swine Waste through a Silicone Membrane in an Aerobic Chamber Improves Biogas Quality and Wastewater Malodors

Transactions of the ASABE (2012)

John H. Loughrin Kimberly Cook N. Lovanh

During the course of experiments designed to lower emission of gases and malodors from swine waste stored in subfloor deep pits, we found that carbon dioxide concentrations in the waste slurry biogas were greatly lowered, resulting in greater relative concentrations of methane. In these experiments, swine waste slurry was circulated through silicone hosing located in an aeration tank, the hose allowing for the passage of small molecules such as methane and malodors. The aeration tank employed a minimal growth medium and chopped silicone to absorb potentially toxic compounds that might slow bacterial growth. Malodors were reduced in treatments. Methane and carbon dioxide were also reduced, especially in the case of carbon dioxide, where concentrations were reduced by almost 80%. The net result of this was methane comprising about 90% of the biogas, as compared to only 70% of the biogas produced by controls. This was due to more bicarbonate buffering in treated slurries, resulting in higher slurry pH. In experiments in which the silicone rubber was omitted from aeration tanks, malodors were still removed efficiently. While carbon dioxide in treated slurry biogas was again greatly reduced, methane concentrations were not. At the end of the experiment control biogas consisted of 75% methane, while in treated biogas methane comprised 95%. In control and treated slurries, Clostridia spp. and Bacteroides spp. comprised over 50% of the total population. Clone sequences from bacterial populations in the aeration tanks grouped with the Proteobacteria and Actinobacteria, two microbial groups with representatives often associated with biodegradation and bioremediation.

Biogas

10.13031/2013.42355

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Reduction of Malodorous Compounds from Liquid Swine Manure by a Multi-Stage Treatment System

Applied Engineering in Agriculture (2006)

John H. Loughrin A. A. Szogi Matías B. Vanotti

A full-scale swine wastewater treatment system was designed and implemented to replace anaerobic lagoon treatment systems with a three-stage process of solids separation, biological nitrogen (N) removal, and phosphorus recovery. Our study had the objectives of evaluating both the system's efficiency for odor control and water quality parameters that better indicate odor reduction. This report presents data on the concentration in liquid of six selected malodorous compounds (phenol, p-cresol, p-ethylphenol, p-propylphenol, indole, and skatole) and 15 water quality parameters measured at the three successive stages of the treatment process. Solid phase extraction of odor compounds showed that the concentrations of malodorous compounds were reduced by almost 98% in the treated effluent as compared to untreated raw flushed manure. The majority of this odor reduction occurred during biological N treatment. No single water quality parameter served as the sole indicator for the levels of all six odor compounds that we measured in wastewater. Except for phenol, the levels of ammonia N and electrical conductivity (EC) measurements were highly correlated with reduction of individual malodorous compounds in wastewater. Seven out of 15 parameters measured (soluble COD, soluble BOD, TKN, ammonia-N, nitrate-N, alkalinity, and EC) were found to be highly related to reduction of total measured malodorous compounds. These results suggest that selected water quality parameters in swine wastewater could assist to evaluate odor control measures when no sensory analysis or appropriate analytical equipment is available. They also indicate that treatment systems incorporating biological N removal can greatly reduce malodorous compounds in liquid swine manure.

Alkalinity

Biofilter

Kjeldahl method

Skatole

10.13031/2013.22258

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Plant Volatiles Inhibit Pollen Germination of Apple and Other Species

HortScience (1992)

Douglas D. Archbold Thomas R. Hamilton–Kemp John H. Loughrin

were collected from field-grown trees ‘at full bloom. With the exception of the rose petals, all tissues were tested either intact or macerated by light grinding in a mortar and pestle. In addition, to determine if ethylene released upon maceration had an effect, intact tomato leaves were dipped in 1000 ppm 2-chloroethyl phosphonic acid (ethephon) before bioassay. After 2 h, microphotographs ( × 40) of the pollen were taken. Four fields from each agar block were photographed. Total and germinated pollen grains were counted from the photographs, recording only single grains on the agar surface. Grains were classified as germinated when the pollen tube length exceeded the diameter of the grain. Percent germination values were derived for each treatment and tested by analysis of variance. After determining that data transformation was not necessary, treatments means were compared by Dunnett’s test.

Maceration (sewage)

10.21273/hortsci.27.3.267

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Abundances of Tetracycline Resistance Genes and Tetracycline Antibiotics during Anaerobic Digestion of Swine Waste

Journal of Environmental Quality (2018)

Melanie Couch Getahun E. Agga John Kasumba Rohan R. Parekh John H. Loughrin

The impact of anaerobic digestion of animal waste on the persistence of antibiotic resistance genes (ARGs) and antibiotics is not widely studied. Two identical, 800-L digesters seeded with swine slurry were followed up to 100 d in three separate trials. The trials received varying amounts of antibiotic-free corn ( L.) mixed with water to maintain the digestion process. Biogas production, seven tetracycline resistance () genes, and three tetracyclines and their transformation products were measured. Biogas production proportionally increased as the feeding loads increased between trials. In Trial 1, log gene copies showed small but statistically significant ( < 0.01) increases during digestion. In Trial 2, anaerobic digestion did not have a significant ( > 0.05) effect except for significant reductions in B ( < 0.0001) and G ( = 0.0335) log gene copies. In Trial 3, which received the highest amount of corn mix, log copies of the 16S ribosomal RNA and the genes significantly ( < 0.0001) reduced over time during digestion. Up to 36 μg L tetracycline, 112 μg L chlortetracycline, 11.9 mg L isochlortetracycline, and 30 μg L 4-epitetracycline were detected both in the liquid and solid digestates. Results of this study revealed that although anaerobic digestion of swine waste can produce useful biogas, it does not result in complete removal of bacteria, ARGs, and antibiotics regardless of differences in the feeding loads between trials. Further effluent and sludge treatments are required prior to their downstream use in crop production to minimize emergence and environmental dissemination of antimicrobial-resistant bacteria through animal manure.

Chlortetracycline

Tetracycline antibiotics

Digestion

Biogas

10.2134/jeq2018.09.0331

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Citations (31)

FLORAL-DERIVED VOLATILE COMPOUNDS: A ROLE IN POLLINATION?

HortScience (1990)

Douglas D. Archbold Thomas R. Hamilton–Kemp John H. Loughrin

Volatile compounds, commonly produced by flowers during bloom, have been described as insect attractants. Some of these compounds stimulate Pinus pollen germination in vitro (French et al., 1979, J. Agric. Fd. Chem., 27184-187), suggesting that such compounds may do the same in vivo. Red Delicious apple pollen was germinated on agar in a simple, enclosed in vitro bioassay system in the presence of a number of plant tissues, including apple, tomato, and chrysanthemum leaves, apple flowers, rose petals, and apple fruit slices. These tissues represent a diversity of types of volatile compounds, Pollen germination was recorded by microphotography after 1 and 2 hours, and percent germination was determined. Although stimulation of germination was not observed, macerated tomato leaves inhibited it. To determine if the volatile characteristics of cultivars differ, flowers of Red Delicious and Golden Delicious apple were harvested at full bloom. Their volatiles were collected, identified, and quantitated by capillary GC-MS. Among 8 major compounds common in the two cultivars, several quantitative differences were observed. These results will be discussed in relation to the potential role of volatiles in pollen germination.

Petal

10.21273/hortsci.25.9.1128d

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Heat Treatment Temporarily Inhibits Aroma Volatile Compound Emission from Golden Delicious Apples

Journal of Agricultural and Food Chemistry (1997)

Elazar Fallik Douglas D. Archbold Thomas R. Hamilton–Kemp John H. Loughrin Randall W. Collins

Volatile compounds were collected by porous polymer trapping from Golden Delicious apples (Malus domestica Borkh.) that had been heat-treated for 4 days at 38 °C, a treatment developed to reduce physiological and pathological disorders during storage, and then stored at 1 °C. Heat treatment of apple fruits markedly inhibited emission of total volatile esters (compounds commonly associated with apple aroma) and total volatiles (comprised principally of the volatile esters and α-farnesene) of apple within 1 day of treatment. However, after an extended refrigerated storage at 1 °C, the heat-treated fruit recovered and produced more total volatiles, increasing from 4% compared to non-heat-treated fruit directly after heat treatment to 145% of non-heat-treated fruit after 6 weeks of storage. Total volatile production of non-heat-treated fruit declined over 5-fold during the 6 weeks of cold storage, while that of heat-treated fruit increased over 6-fold. Total volatile esters from heat-treated fruit declined after 1 week of storage but had increased 4-fold from the initial sampling date after 6 weeks of storage. The heat treatment effect on emission of volatile compounds was observed immediately following heat treatment. The fruit cuticle and epidermis were not barriers to volatile emission by heat-treated fruit since slicing both heat-treated and non-heat-treated fruit after treatment resulted in total volatile yields similar to intact fruit. Heat treatment apparently temporarily inhibited but did not destroy, or destroyed but allowed resynthesis of, the enzyme systems catalyzing volatile compound synthesis as shown by increasing emission over time by heat-treated apples. Keywords: Esters; postharvest storage; flavor; Malus domestica

Malus

10.1021/jf970358n

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Citations (63)

The Effect of Mono- and Di-Saccharides on the Microbiome of Dairy Cow Manure and Its Odor

Microorganisms (2024)

John H. Loughrin Getahun E. Agga

In a previous experiment, we showed that the odor of Bos taurus manure slurries could be improved by anaerobic incubation with the sugars glucose, lactose, and sucrose. This improvement was due to reductions in the concentrations of malodorants, including dimethyl disulfide, p-cresol, p-ethylphenol, indole, and skatole, and a shift to the production of fruity esters, including ethyl butyrate and propyl propanoate. Due to large concentrations of lactic acid produced by the sugar-amended manure slurries, we inferred that lactic acid bacteria were involved in improving the manure slurry odor. Here, through 16S rRNA amplicon sequencing for microbiome analysis, we show that lactic acid bacterial growth was promoted by the addition of all three sugars. Lactobacillus buchneri and an unknown Lactobacillus sp. were the most prominent lactic acid bacteria stimulated by sugar addition. Lactobacillales were found only in trace abundances in unamended manure slurries. The relative abundance of orders such as Clostridiales, Bifidobacteriales, and Erysipelotrichales were not noticeably affected by sugar amendment. However, the disaccharides lactose and sucrose seemed to increase the relative abundance of Bifidobacterium, whereas the monosaccharide glucose did not. We conclude that lactic acid bacteria are the primary bacteria involved in improving odor in dairy cow manure slurries and present strategies to enhance their abundance in animal wastes.

Monosaccharide

Silage

10.3390/microorganisms13010052

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