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[No abstract available]
In this chapter, we provide an overview of antimicrobial resistant (AMR) bacteria in wildlife through the presentation of general trends of occurrence among both captive and free-ranging wild animal populations, discussion of importance to human health and wildlife conservation, and identification of priority areas for future research and monitoring efforts. Once most commonly identified in humans and domestic animals, AMR bacteria have now been reported to be widespread among free-ranging and captive wildlife and the broader environment. Antimicrobial resistance has been identified in wildlife inhabiting nearly every country, region, and habitat type from which samples have been obtained, although occurrence may be more common in animals that occupy anthropogenically impacted environments. Though AMR bacteria identified in free-ranging wildlife have generally not been associated with direct health impacts to the host, specific bacteria and types of resistance found in wildlife may be clinically relevant to humans. Furthermore, AMR bacteria harbored by captive or free-ranging animals may complicate veterinary treatment of captive, rare, or vulnerable wildlife provided care. Future investigations may obtain important information on the acquisition and dissemination of AMR bacteria by wildlife through the comparison of resistance harbored by bacteria from wildlife and the environments they occupy. The identification of specific environmental pathways through which resistance may be acquired would help to guide the development of intervention strategies to interrupt further spread of antimicrobial resistance to, from, and among wildlife. Implications of such strategies may also extend more broadly to promote domestic animal, human, and environmental health.
No abstract available at this time
Antibiotics are used to maintain healthy livestock and to promote weight gain in concentrated animal feed operations. Antibiotics rarely are metabolized completely by livestock and, thus, are often present in livestock waste and in waste-treatment lagoons. The introduction of antibiotics into anaerobic lagoons commonly used for swine waste treatment has the potential for negative impacts on lagoon performance, which relies on a consortium of microbes ranging from fermentative microorganisms to methanogens. To address this concern, the effects of eight common veterinary antibiotics on anaerobic activity were studied. Anaerobic microcosms, prepared from freshly collected lagoon slurries, were amended with individual antibiotics at 10 mg/L for the initial screening study and at 1, 5, and 25 mg/L for the dose-response study. Monitored metabolic indicators included hydrogen, methane, and volatile fatty acid concentrations as well as chemical oxygen demand. The selected antibiotics significantly inhibited methane production relative to unamended controls, thus indicating that antibiotics at concentrations commonly found in swine lagoons can negatively impact anaerobic metabolism. Additionally, historical antibiotic usage seems to be a potential factor in affecting methane production. Specifically, less inhibition of methane production was noted in samples taken from the lagoon with a history of multiple-antibiotic use.
Environmental releases of antibiotics from concentrated animal feeding operations (CAFOs) are of increasing regulatory concern. This study investigates the use and occurrence of antibiotics in dairy CAFOs and their potential transport into first-encountered groundwater. On two dairies we conducted four seasonal sampling campaigns, each across 13 animal production and waste management systems and associated environmental pathways: application to animals, excretion to surfaces, manure collection systems, soils, and shallow groundwater. Concentrations of antibiotics were determined using on line solid phase extraction (OLSPE) and liquid chromatography-tandem mass spectrometry (LC/MS/MS) with electrospray ionization (ESI) for water samples, and accelerated solvent extraction (ASE) LC/MS/MS with ESI for solid samples. A variety of antibiotics were applied at both farms leading to antibiotics excretion of several hundred grams per farm per day. Sulfonamides, tetracyclines, and their epimers/isomers, and lincomycin were most frequently detected. Yet, despite decades of use, antibiotic occurrence appeared constrained to within farm boundaries. The most frequent antibiotic detections were associated with lagoons, hospital pens, and calf hutches. When detected below ground, tetracyclines were mainly found in soils, whereas sulfonamides were found in shallow groundwater reflecting key differences in their physicochemical properties. In manure lagoons, 10 compounds were detected including tetracyclines and trimethoprim. Of these 10, sulfadimethoxine, sulfamethazine, and lincomycin were found in shallow groundwater directly downgradient from the lagoons. Antibiotics were sporadically detected in field surface samples on fields with manure applications, but not in underlying sandy soils. Sulfadimethoxine and sulfamethazine were detected in shallow groundwater near field flood irrigation gates, but at highly attenuated levels.
Antibiotics are used at therapeutic levels to treat disease; at slightly lower levels as prophylactics; and at low, subtherapeutic levels for growth promotion and improvement of feed efficiency. Over 88% of swine producers in the United States gave antimicrobials to grower/finisher pigs in feed as a growth promoter in 2000. It is estimated that ca . 75% of antibiotics are not absorbed by animals and are excreted in urine and feces. The extensive use of antibiotics in swine production has resulted in antibiotic resistance in many intestinal bacteria, which are also excreted in swine feces, resulting in dissemination of resistance genes into the environment. To assess the impact of manure management on groundwater quality, groundwater samples have been collected near two swine confinement facilities that use lagoons for manure storage and treatment. Several key contaminant indicators-including inorganic ions, antibiotics, and antibiotic resistance genes-were analyzed in groundwater collected from the monitoring wells. Chloride, ammonium, potassium, and sodium were predominant inorganic constituents in the manure samples and served as indicators of groundwater contamination. Based on these analyses, shallow groundwater has been impacted by lagoon seepage at both sites. Liquid chromatography-mass spectroscopy (LC-MS) was used to measure the dissolved concentrations of tetracycline, chlortetracycline, and oxytetracycline in groundwater and manure. Although tetracyclines were regularly used at both facilities, they were infrequently detected in manure samples and then at relatively trace concentrations. Concentrations of all tetracyclines and their breakdown products in the groundwater sampled were generally less than 0.5 ??g/L.</ p> Bacterial tetracycline resistance genes served as distinct genotypic markers to indicate the dissemination and mobility of antibiotic resistance genes that originated from the lagoons. Applying PCR to genomic DNA extracted from the lagoon and groundwater samples, four commonly occurring tetracycline (tet) resistance genes-tet(M), tet(O), tet(Q), and tet(W)-were detected. The detection frequency of tet genes was much higher in wells located closer to and down-gradient from the lagoons than in wells more distant from the lagoons. These results suggested that in the groundwater underlying both facilities tetracycline resistance genes exist and are somewhat persistent, but that the distribution and potentially the flux for each tet gene varied throughout the study period.
The U.S. Geological Survey - in cooperation with the Ohio Water Development Authority; National Park Service; Cities of Aurora, Bedford, Bedford Heights, Solon, and Twinsburg; and Portage and Summit Counties - and in collaboration with the Ohio Environmental Protection Agency, did a study to determine the occurrence and distribution of organic wastewater compounds (OWCs) in the Tinkers Creek watershed in northeastern Ohio. In the context of this report, OWCs refer to a wide range of compounds such as antibiotics, prescription and nonprescription pharmaceuticals, personal-care products, household and industrial compounds (for example, antimicrobials, fragrances, surfactants, fire retardants, and so forth) and a variety of other chemicals. Canisters containing polar organic integrative sampler (POCIS) and semipermeable membrane device (SPMD) media were deployed instream for a 28-day period in Mayand June 2006 at locations upstream and downstream from seven wastewater-treatment-plant (WWTP) outfalls in the Tinkers Creek watershed, at a site on Tinkers Creek downstream from all WWTP discharges, and at one reference site each in two nearby watersheds (Yellow Creek and Furnace Run) that drain to the Cuyahoga River. Streambed-sediment samples also were collected at each site when the canisters were retrieved. POCIS and SPMDs are referred to as 'passive samplers' because they sample compounds that they are exposed to without use of mechanical or moving parts. OWCs detected in POCIS and SPMD extracts are referred to in this report as 'detections in water' because both POCIS and SPMDs provided time-weighted measures of concentration in the stream over the exposure period. Streambed sediments also reflect exposure to OWCs in the stream over a long period of time and provide another OWC exposure pathway for aquatic organisms. Four separate laboratory methods were used to analyze for 32 antibiotic, 20 pharmaceutical, 57 to 66 wastewater, and 33 hydrophobic compounds. POCIS and streambed-sediment extracts were analyzed by both the pharmaceutical and wastewater methods. POCIS extracts also were analyzed by the antibiotic method, and SPMD extracts were analyzed by the hydrophobic-compound method. Analytes associated with a given laboratory method are referred to in aggregate by the method name (for example, antibiotic-method analytes are referred to as 'antibiotic compounds') even though some analytes associated with the method may not be strictly classified as such. In addition, some compounds were included in the analyte list for more than one laboratory method. For a given sample matrix, individual compounds detected by more than one analytical method are included independently in counts for each method. A total of 12 antibiotic, 20 pharmaceutical, 41 wastewater, and 22 hydrophobic compounds were detected in water at one or more sites. Eight pharmaceutical and 37 wastewater compounds were detected in streambed sediments. The numbers of detections at reference sites tended to be in the low range of detection counts observed in the Tinkers Creek watershed for a given analytical method. Also, the total numbers of compounds detected in water and sediment at the reference sites were less than the total numbers of compounds detected at sites in the Tinkers Creek watershed. With the exception of hydrophobic compounds, it was common at most sites to have more compounds detected in samples collected downstream from WWTP outfalls than in corresponding samples collected upstream from the outfalls. This was particularly true for antibiotic, pharmaceutical, and wastewater compounds in water. In contrast, it was common to have more hydrophobic compounds detected in samples collected upstream from WWTP outfalls than downstream. Caffeine, fluoranthene, N,N-diethyl-meta-toluamide (DEET), phenanthrene, and pyrene were detected in water at all sites in the Tinkers Creek watershed, irrespective of whether the site was upstream or downs
Concern over the presence of contaminants of emerging concern, such as pharmaceutical compounds, hormones, and organic wastewater compounds (OWCs), in waters of the United States and elsewhere is growing. Laboratory techniques developed within the last decade or new techniques currently under development within the U.S. Geological Survey now allow these compounds to be measured at concentrations in nanograms per liter. These new laboratory techniques were used in a reconnaissance study conducted by the U.S. Geological Survey, in cooperation with the Pennsylvania Department of Environmental Protection, to determine the occurrence of contaminants of emerging concern in streams, streambed sediment, and groundwater of Pennsylvania. Compounds analyzed for in the study are pharmaceuticals (human and veterinary drugs), hormones (natural and synthetic), and OWCs (detergents, fragrances, pesticides, industrial compounds, disinfectants, polycyclic aromatic hydrocarbons, fire retardants and plasticizers). Reconnaissance sampling was conducted from 2006 to 2009 to identify contaminants of emerging concern in (1) groundwater from wells used to supply livestock, (2) streamwater upstream and downstream from animal feeding operations, (3) streamwater upstream from and streamwater and streambed sediment downstream from municipal wastewater effluent discharges, (4) streamwater from sites within 5 miles of drinking-water intakes, and (5) streamwater and streambed sediment where fish health assessments were conducted. Of the 44 pharmaceutical compounds analyzed in groundwater samples collected in 2006 from six wells used to supply livestock, only cotinine (a nicotine metabolite) and the antibiotics tylosin and sulfamethoxazole were detected. The maximum concentration of any contaminant of emerging concern was 24 nanograms per liter (ng/L) for cotinine, and was detected in a groundwater sample from a Lebanon County, Pa., well. Seven pharmaceutical compounds including acetaminophen, caffeine, carbamazepine, and the four antibiotics tylosin, sulfadimethoxine, sulfamethoxazole, and oxytetracycline were detected in streamwater samples collected in 2006 from six paired stream sampling sites located upstream and downstream from animal-feeding operations. The highest reported concentration of these seven compounds was for the antibiotic sulfamethoxazole (157 ng/L), in a sample from the downstream site on Snitz Creek in Lancaster County, Pa. Twenty-one pharmaceutical compounds were detected in streamwater samples collected in 2006 from five paired stream sampling sites located upstream or downstream from a municipal wastewater-effluent-discharge site. The most commonly detected compounds and maximum concentrations were the anticonvulsant carbamazepine, 276 ng/L; the antihistamine diphenhydramine, 135 ng/L; and the antibiotics ofloxacin, 329 ng/L; sulfamethoxazole, 1,340 ng/L; and trimethoprim, 256 ng/L. A total of 51 different contaminants of emerging concern were detected in streamwater samples collected from 2007 through 2009 at 13 stream sampling sites located downstream from a wastewater-effluent-discharge site. The concentrations and numbers of compounds detected were higher in stream sites downstream from a wastewater-effluent-discharge site than in stream sites upstream from a wastewater-effluent-discharge site. This finding indicates that wastewater-effluent discharges are a source of contaminants of emerging concern; these contaminants were present more frequently in the streambed-sediment samples than in streamwater samples. Antibiotic compounds were often present in both the streamwater and streambed-sediment samples, but many OWCs were present exclusively in the streambed-sediment samples. Compounds with endocrine disrupting potential including detergent metabolites, pesticides, and flame retardants, were present in the streamwater and streambed-sediment samples. Killinger Creek, a stream where wastewater-effluent discharges contribute a large percentage of the total flow, stands out as a stream with particularly high numbers of compounds detected and detected at the highest concentrations measured in the reconnaissance sampling. Nineteen contaminants of emerging concern were detected in streamwater samples collected quarterly from 2007 through 2009 at 27 stream sites within 5 miles of a drinking-water intake. The number of contaminants and the concentrations detected at the stream sites within 5 miles of drinking-water intakes were generally very low (concentrations less than 50 ng/L), much lower than those at sites downstream from a wastewater-effluent discharge. The most commonly detected compounds and maximum concentrations were caffeine, 517 ng/L; carbamazepine, 95 ng/L; sulfamethoxazole, 146 ng/L; and estrone, 3.15 ng/L. The concentrations and frequencies of detection of some of the contaminants of emerging concern appear to vary by season, which could be explained by compound use, flow regime, or differences in degradation rates. Concentrations of some contaminants were associated with lower flows as a result of decreased in-stream dilution of wastewater effluents or other contamination sources. Twenty-two contaminants of emerging concern were detected once each in streamwater samples collected in 2007 and 2008 from 16 fish-health stream sites located statewide. The highest concentrations were for the OWCs, including flame retardants tri(2-butoxyethyl)phosphate (604 ng/L) and tri(2-chloroethyl)phosphate (272 ng/L) and the fragrance isoquinoline (330 ng/L). Far fewer numbers of contaminants of emerging concern were detected at the fish-health sites than at the wastewater-effluent-discharge sites. Most of the fish-health sites were not located directly downstream from a wastewater-effluent discharge, but there were multiple wastewater-effluent discharges in the drainage basins upstream from the sampling sites. No distinct pattern of contaminant occurrence could be discerned for the fish-health stream sites
Bacterial kidney disease (BKD) caused by Renibacterium salmoninarum (Rs) occurs nearly worldwide where wild or cultured salmonid fishes are present. Control of BKD is confounded by its two modes of transmission, horizontal (fish-to-fish) and vertical (from female parent to progeny via the eggs). A highly successful BKD control strategy employed in Pacific Northwest hatcheries culturing spring Chinook salmon ( Oncorhynchus tshawytscha ) includes: (1) injecting pre-spawning adults with a macrolide antibiotic to improve survival and reduce Rs infection levels, (2) broodstock culling of highly infected females and (3) improved fish husbandry. However, the future availability of the injectable macrolide antibiotic (erythromycin) used for adults is uncertain. This drug shortage has resulted in an urgent need to identify a replacement injectable antibiotic to ensure continued successful control of BKD. The research conducted was intended to provide information for addressing this need via preliminary tests of the safety and efficacy of a new macrolide antibiotic, injectable tulathromycin, which is sold under the trade name DRAXXIN® (Zoetis Animal Health). A long-term goal is to reduce or eliminate the use of antibiotic treatment in spring Chinook salmon hatchery culture. Non-treated females were included in the study to provide empirical data in support of this goal. A subset of pre-spawning spring Chinook salmon at Leavenworth NFH was injected on July 10, 2014 with DRAXXIN at 5 mg per kg body weight (31 fish, left pelvic fin clip). Another subset of females (30 fish, right pelvic fin clip) was left uninjected. The surviving fish (31 DRAXXIN-injected fish and 28 uninjected fish) were spawned between August 18 and September 2, 2014. Although there were apparent trends toward higher pre-spawn survival and lower Rs prevalence and levels for the DRAXXIN-injected females in comparison to the uninjected females, the differences were not statistically significant for any of the Rs assays used (P > 0.05). Based on USFWS enzyme-linked immnosorbent assay (ELISA) test results of kidney tissue samples from the spawning females, egg lots from DRAXXIN-injected and uninjected females were assigned to Rs vertical transmission risk groups (low, medium or high). A subset of 220 eyed eggs from each female was transferred to the Western Fisheries Research Center (USGS) on October 8, 2014, hatched and reared until the study was terminated on September 22, 2015. The study results provided no evidence that DRAXXIN injection of adult female Chinook salmon affected their fecundity, egg eye-up, or survival and growth of progeny fry. There was little evidence of Rs infection in progeny of either DRAXXIN-injected or uninjected females, so the effect of DRAXXIN injection on vertical transmission of Rs could not be assessed. To adequately evaluate the efficacy of DRAXXIN injection for reducing Rs vertical transmission to progeny, additional studies should be conducted with larger numbers of DRAXXIN-injected and uninjected Chinook salmon females with a greater range of Rs levels.
Stressors such as antibiotics, herbicides, and pollutants are becoming increasingly common in the environment. The effects of stressors on populations are typically studied in homogeneous, nonspatial settings. However, most populations in nature are spatially distributed over environmentally heterogeneous landscapes with spatially restricted dispersal. Little is known about the effects of stressors in these more realistic settings. Here, we combine laboratory experiments with novel mathematical theory to rigorously investigate how a stressor’s physiological effect and spatial distribution interact with dispersal to influence population dynamics. We prove mathematically that if a stressor increases the death rate and/or simultaneously decreases the population growth rate and yield, a homogeneous distribution of the stressor leads to a lower total population size than if the same amount of the stressor was heterogeneously distributed. We experimentally test this prediction on spatially distributed populations of budding yeast ( Saccharomyces cerevisiae ). We find that the antibiotic cycloheximide increases the yeast death rate but reduces the growth rate and yield. Consistent with our mathematical predictions, we observe that a homogeneous spatial distribution of cycloheximide minimizes the total equilibrium size of experimental metapopulations, with the magnitude of the effect depending predictably on the dispersal rate and the geographic pattern of antibiotic heterogeneity. Our study has implications for assessing the population risk posed by pollutants, antibiotics, and global change and for the rational design of strategies for employing toxins to control pathogens and pests.
Recently, our attention has focused on the low level detection of many antibiotics, pharmaceuticals, and other organic chemicals in water resources. The limited studies available suggest that urban or rural streams receiving wastewater effluent are more susceptible to contamination. The purpose of this study was to evaluate the occurrence of antibiotics, pharmaceuticals, and other organic chemicals at 18 sites on seven selected streams in Arkansas, USA, during March, April, and August 2004. Water samples were collected upstream and downstream from the influence of effluent discharges in northwestern Arkansas and at one site on a relatively undeveloped stream in north-central Arkansas. At least one antibiotic, pharmaceutical, or other organic chemical was detected at all sites, except at Spavinaw Creek near Mayesville, Arkansas. The greatest number of detections was observed at Mud Creek downstream from an effluent discharge, including 31 pharmaceuticals and other organic chemicals. The detection of these chemicals occurred in higher frequency at sites downstream from effluent discharges compared to those sites upstream from effluent discharges; total chemical concentration was also greater downstream. Wastewater effluent discharge increased the concentrations of detergent metabolites, fire retardants, fragrances and flavors, and steroids in these streams. Antibiotics and associated degradation products were only found at two streams downstream from effluent discharges. Overall, 42 of the 108 chemicals targeted in this study were found in water samples from at least one site, and the most frequently detected organic chemicals included caffeine, phenol, para -cresol, and acetyl hexamethyl tetrahydro naphthalene (AHTN).
In 2003 a team of scientists from West Virginia Division of Natural Resources and the U. S. Geological Survey found a high incidence of an intersex condition, oocytes in the testes, among smallmouth bass (Micropterus dolomieu) in the South Branch Potomac River and the Cacapon River of West Virginia, indicating the possible presence of endocrine-disrupting compounds (EDCs). Possible sources of EDCs include municipal and domestic wastewater, and agricultural and industrial activities. Several sampling strategies were used to identify emerging contaminants, including potential EDCs, and their possible sources in these river basins and at an out-of-basin reference site. Passive water-sampling devices, which accumulate in-stream organic chemical compounds, were deployed for 40-41 days at 8 sampling sites. Sampler extracts were analyzed for a broad range of polar and non-polar organic compounds including pesticides, flame retardants, pharmaceuticals, and personal-care products. Analysis of passive-sampler extracts found 4 compounds; hexachloro-benzene; pentachloroanisole; 2,2',4,4',5-penta-bromo-diphenyl ether (BDE 47); and 2,2',4,4',6-penta-bromo-diphenyl ether (BDE 99) to be present at every sampled site, including the reference site, and several sites had detectable quantities of other compounds. No detectable quantity of any antibiotics was found in any passive-sampler extract. Effluent samples were analyzed for 39 antibiotics as tracers of human and agricultural waste. Additionally, poultry-processing plant effluent was sampled for roxarsone, an organoarsenic compound used as a poultry-feed additive, and other arsenic species as tracers of poultry waste. Antibiotics were detected in municipal wastewater, aquaculture, and poultry-processing effluent, with the highest number of antibiotics and the greatest concentrations found in municipal effluent. Arsenate was the only arsenic species detected in the poultry-processing plant effluent, at a concentration of 1.0 ?g/L. Water samples were collected from 7 stream sites and analyzed for arsenic species, including roxarsone. Arsenate was detected in samples from 6 of the 7 stream samples, in concentrations ranging from 0.3 to 0.5 ?g/L. Additionally, the analysis of smallmouth bass blood plasma for potential EDCs indicated the presence of several compounds including some found in the passive sampler extracts, specifically BDE 47 and BDE 99. Data from this reconnaissance will help to focus efforts for further studies of the occurrence of emerging contaminants, EDCs, and intersex in smallmouth bass in these Potomac River tributaries.
The Comprehensive Everglades Restoration Plan has identified highly treated wastewater as a possible water source for the restoration of natural water flows and hydroperiods in selected coastal areas, including the Biscayne Bay coastal wetlands. One potential source of reclaimed wastewater for the Biscayne Bay coastal wetlands is the effluent from the South District Wastewater Treatment Plant in southern Miami-Dade County. The U.S. Geological Survey, in cooperation with the Comprehensive Everglades Restoration Plan Wastewater Reuse Technology Pilot Project Delivery Team, initiated a study to assess the presence of emerging contaminants of concern in the South District Wastewater Treatment Plant influent and effluent using current wastewater-treatment methods. As part of the study, 24-hour composite and discrete samples were collected at six locations (influent at plants 1 and 2, effluent pump, reuse train, chlorine dioxide unit, and ultraviolet pilot unit) at the plant during: (1) a dry-season, low-flow event on March 2-3, 2004, with an average inflow rate of 83.7 million gallons per day; (2) a wet-season, average-flow event on July 20-21, 2004, with an average inflow rate of 89.7 million gallons per day; and (3) high-rate disinfection tests on October 5 and 20, 2004, with average flow rates of 84.1 and 119.6 million gallons per day, respectively. During these four sampling events, 26, 27, 29, and 35 constituents were detected, respectively. The following transformations in concentration were determined in the waste stream: -100 to 180 percent at the effluent pump and -100 to 85 percent at the reuse train on March 2-3, 2004, and -100 to 1,609 percent at the effluent pump and -100 to 832 percent at the reuse train on July 20-21, 2004; -100 to -37 percent at the effluent pump, -100 to -62 percent at the reuse train, -100 to -56 percent at the chlorine dioxide unit, and -100 to -40 percent at the ultraviolet pilot unit on October 5, 2004; and -100 to -4 percent at the effluent pump, -100 to 17 percent at the reuse train, -100 to -40 percent at the chlorine dioxide unit, and -100 to -14 percent at the ultraviolet pilot unit on October 20, 2004. Samples were tested for detection of household and industrial (organic) wastewater compounds, pharmaceutical compounds, antibiotic compounds, and hormones in influent. Two 'known' endocrine disrupting compounds?17 beta-estradiol (E2) and diethoxynonylphenol? and four 'suspected' endocrine-disrupting compounds?1,4-dichlorobenzene, benzophenone, tris(2-chloroethyl) phosphate, and tris(dichloroisopropyl) phosphate?were detected during these sampling events. Phenanthrene and indole showed the greatest concentration ranges and highest concentrations for the organic wastewater compounds. Acetaminophen showed the greatest concentration range and highest concentration, and warfarin showed the smallest concentration range for the pharmaceutical compounds. Sulfamethoxazole (a sulfonamide) showed the greatest concentration range and highest concentration, and sulfathiozole (also a sulfonamide) showed the smallest concentration range for the antibiotic compounds. Two hormones, 17 beta-estradiol (E2) and estrone (E1), were detected in influent. Samples were also tested for detection of organic wastewater compounds, pharmaceutical compounds, antibiotic compounds, and hormones in effluent. Indole showed the greatest concentration range and highest concentration, and triphenyl phosphate showed the smallest concentration range for the organic wastewater compounds. Dehydronifedipine showed the greatest concentration range and highest concentration, and warfarin had the smallest concentration range for the pharmaceutical compounds. Anhydro-erythromycin (a macrolide degradation product) showed the greatest concentration range, and sulfadiazine (a sulfonamide) and tetracycline showed the lowest concentration ranges for the antibiotic compounds. One hormone, 17 beta-estradiol (E2), was det
Selected organic wastewater compounds, such as household, industrial, and agricultural-use compounds, sterols, pharmaceuticals, and antibiotics, were measured at eight sites classified as drinking-water supplies in the Triangle Area of North Carolina. From October 2002 through July 2005, seven of the sites were sampled twice, and one site was sampled 28 times, for a total of 42 sets of environmental samples. Samples were analyzed for as many as 126 compounds using three laboratory analytical methods. These methods were developed by the U.S. Geological Survey to detect low levels (generally less than or equal to 1.0 microgram per liter) of the target compounds in filtered water. Because analyses were conducted on filtered samples, the results presented in this report may not reflect the total concentration of organic wastewater compounds in the waters that were sampled. Various quality-control samples were used to quality assure the results in terms of method performance and possible laboratory or field contamination. Of the 108 organic wastewater compounds that met method performance criteria, 24 were detected in at least one sample during the study. These 24 compounds included 3 pharmaceutical compounds, 6 fire retardants and plasticizers, 3 antibiotics, 3 pesticides, 6 fragrances and flavorants, 1 disinfectant, and 2 miscellaneous-use compounds, all of which likely originated from a variety of domestic, industrial, and agricultural sources. The 10 most frequently detected compounds included acetyl-hexamethyl tetrahydronaphthalene and hexahydro-hexamethyl cyclopentabenzopyran (synthetic musks that are widely used in personal-care products and are known endocrine disruptors); tri(2-chloroethyl) phosphate, tri(dichloroisopropyl) phosphate, and tributyl phosphate (fire retardants); metolachlor (herbicide); caffeine (nonprescription stimulant); cotinine (metabolite of nicotine); acetaminophen (nonprescription analgesic); and sulfamethoxazole (prescription antibiotic). The occurrence and distribution of organic wastewater compounds varied considerably among sampling sites, but at least one compound was detected at every location. The most organic wastewater compounds (19) were detected at the Neuse River above U.S. 70 at Smithfield, where two-thirds of the total number of samples were collected. The fewest organic wastewater compounds (1) were detected at the Eno River at Hillsborough. The detection of multiple organic wastewater compounds was common, with a median of 3.5 and as many as 12 compounds observed in individual samples. Some compounds, including acetaminophen, cotinine, tri(2-chloroethyl) phosphate, and metolachlor, were detected at numerous sites and in numerous samples, indicating that they are widely distributed in the environment. Other organic wastewater compounds, including acetyl-hexamethyl tetrahydronaphthalene and hexahydro-hexamethyl cyclopentabenzopyran, were detected in numerous samples but at only one location, indicating that sources of these compounds are more site specific. Results indicate that municipal wastewater may be a source of antibiotics and synthetic musks; however, the three sites in this study that are located downstream from wastewater discharges also receive runoff from agricultural, urban, and rural residential lands. Source identification was not an objective of this study. Concentrations of individual compounds generally were less than 0.5 microgram per liter. No concentrations exceeded Federal drinking-water standards or health advisories, nor water-quality criteria established by the State of North Carolina; however, such criteria are available for only a few of the compounds that were studied. Compared with other surface waters that have been sampled across the United States, the Triangle Area water-supply sites had fewer detections of organic wastewater compounds; however, differences in study design and analytical methods used among studies must be considered when mak
Anaerobic digestion has been suggested as an intervention to attenuate antibiotic resistance genes (ARGs) in livestock manure but supporting data have typically been collected at laboratory scale. Few studies have quantified ARG fate during full-scale digestion of livestock manure. We sampled untreated manure and digestate from seven full-scale mesophilic dairy manure digesters to assess ARG fate through each system. Samples were collected biweekly from December through August (i.e., winter, spring, and summer; n = 235 total) and analyzed by quantitative polymerase chain reaction for intI1 , erm (B), sul1 , tet (A), and tet (W). Concentrations of intI1 , sul1 , and tet (A) decreased during anaerobic digestion, but their removal was less extensive than expected based on previous laboratory studies. Removal for intI1 during anaerobic digestion equaled 0.28 ± 0.03 log 10 units (mean ± SE), equivalent to only 48% removal and notable given intI1 ’s role in horizontal gene transfer and multiple resistance. Furthermore, tet (W) concentrations were unchanged during anaerobic digestion ( p > 0.05), and erm (B) concentrations increased by 0.52 ± 0.03 log 10 units (3.3-fold), which is important given erythromycin's status as a critically important antibiotic for human medicine. Seasonal log 10 changes in intI1 , sul1 , and tet (A) concentrations were ≥50% of corresponding log 10 removals by anaerobic digestion, and variation in ARG and intI1 concentrations among digesters was quantitatively comparable to anaerobic digestion effects. These results suggest that mesophilic anaerobic digestion may be limited as an intervention for ARGs in livestock manure and emphasize the need for multiple farm-level interventions to attenuate antibiotic resistance.
Microorganisms associated with corals are hypothesized to contribute to the function of the host animal by cycling nutrients, breaking down carbon sources, fixing nitrogen, and producing antibiotics. This is the first study to culture and characterize bacteria from Lophelia pertusa, a cold-water coral found in the deep sea, in an effort to understand the roles that the microorganisms play in the coral microbial community. Two sites in the northern Gulf of Mexico were sampled over 2 years. Bacteria were cultured from coral tissue, skeleton, and mucus, identified by 16S rRNA genes, and subjected to biochemical testing. Most isolates were members of the Gammaproteobacteria, although there was one isolate each from the Betaproteobacteria and Actinobacteria. Phylogenetic results showed that both sampling sites shared closely related isolates (e.g. Pseudoalteromonas spp.), indicating possible temporally and geographically stable bacterial-coral associations. The Kirby-Bauer antibiotic susceptibility test was used to separate bacteria to the strain level, with the results showing that isolates that were phylogenetically tightly grouped had varying responses to antibiotics. These results support the conclusion that phylogenetic placement cannot predict strain-level differences and further highlight the need for culture-based experiments to supplement culture-independent studies.
This study, by the U.S. Geological Survey (USGS) in cooperation with the Pennsylvania Department of Environmental Protection (PADEP), provides a compilation of ground-water-quality data for a 28-year period (January 1, 1979, through December 31, 2006) based on water samples from wells and springs. The data are from 14 source agencies or programs—Borough of Carroll Valley, Chester County Health Department, Montgomery County Health Department, Pennsylvania Department of Agriculture, Pennsylvania Department of Environmental Protection 2002 Pennsylvania Water-Quality Assessment, Pennsylvania Department of Environmental Protection Agency Act 537 Sewage Facilities Program, Pennsylvania Department of Environmental Protection-Ambient and Fixed Station Network, Pennsylvania Department of Environmental Protection–North-Central Region, Pennsylvania Department of Environmental Protection–South-Central Region, Pennsylvania Drinking Water Information System, Pennsylvania Topographic and Geologic Survey, Susquehanna River Basin Commission, U.S. Environmental Protection Agency, and the U.S. Geological Survey. The ground-water-quality data from the different source agencies or programs varied in type and number of analyses; however, the analyses are represented by 11 major analyte groups: antibiotics, major ions, microorganisms (bacteria, viruses, and other microorganisms), minor ions (including trace elements), nutrients (predominantly nitrate and nitrite as nitrogen), pesticides, pharmaceuticals, radiochemicals (predominantly radon or radium), volatiles (volatile organic compounds), wastewater compounds, and water characteristics (field measurements, predominantly field pH, field specific conductance, and hardness). For the USGS and the PADEP–North-Central Region, the pesticide analyte group was broken down into fungicides, herbicides, and insecticides. Summary maps show the areal distribution of wells and springs with ground-water-quality data statewide by source agency or program. Summary data tables by source agency or program provide information on the number of wells and springs and samples collected for each of the 35 watersheds and analyte groups. The number of wells and springs sampled for ground-water-quality data varies considerably across Pennsylvania. Of the 24,772 wells and springs sampled, the greatest concentration of wells and springs is in the southeast (Berks, Bucks, Chester, Delaware, Lancaster, Montgomery, and Philadelphia Counties) and in the northwest (Erie County). The number of wells and springs sampled is relatively sparse in north-central (Cameron, Elk, Forest, McKean, Potter, and Warren Counties) Pennsylvania. Little to no data are available for approximately one-fourth of the state. Nutrients and water characteristics were the most frequently sampled major analyte groups—43,025 and 30,583 samples, respectively. Minor ions and major ions were the next most frequently sampled major analyte groups–26,972 and 13,115 samples, respectively. For the remaining 10 major analyte groups, the number of samples collected ranged from a low of 24 samples (antibiotic compounds) to a high of approximately 4,674 samples (microorganisms). The number of samples that exceeded a maximum contaminant level (MCL) or secondary maximum contaminant level (SMCL) by major analyte group also varied. Of the 4,674 samples in the microorganism analyte group, 50.2 percent had water that exceeded an MCL. Of the 4,528 samples collected and analyzed for volatile organic compounds, 23.5 percent exceeded an MCL. Other major analyte groups that frequently exceeded MCLs or SMCLs included major ions (18,343 samples and a 27.7 percent exceedence), minor ions (26,972 samples, 44.7 percent exceedence), pesticides (4,868 samples, 0.7 percent exceedence), water characteristics (30,583 samples, 19.3 percent exceedence), and radiochemicals (1,866 samples, 9.6 percent exceedence). Samples collected and analyzed for antibiotics (24 samples), fungicides (1,273 samples), herbicides (1,470 samples), insecticides (1,424 samples), nutrients (43,025 samples), pharmaceuticals (28 samples), and wastewater compounds (328 samples) had the lowest exceedences of 0.0, 2.4, 1.2, <1.0, 8.3, 0.0, and <1.0 percent, respectively.