Fecal pollution from nonhuman (pets, livestock or wildlife) and human sources is often one of the major factors associated with urbanization that contribute to the degradation of water quality. ...Methods to differentiate animal from human sources of fecal coliform contamination could assist resource managers in developing strategies to protect shellfish harvesting areas and recreational waters. In this study, surface water samples were collected from both a developed and an undeveloped watershed in coastal South Carolina. Influent and effluent samples from several wastewater treatment plants (WWTPs) in the same area were also collected. Most Probable Numbers (MPNs) of fecal coliforms were determined for all samples.
Escherichia coli isolates were analyzed for antibiotic resistance (AR) to 10 antibiotics. Then, AR indices (no. of resistant/total no. of antibiotics tested), were calculated for each isolate and site. Results indicated that MPNs from the WWTP samples were significantly higher than those from the developed watershed which were significantly higher than those from the undeveloped watershed (
p<0.0001). The AR analyses suggested that there was a trend toward increased antibiotic resistance in samples for the urbanized Broad Creek (BC) watershed. In the Okatee River (OR),
E. coli isolates from three sites (20%) showed resistance to a single antibiotic (penicillin) but in BC, isolates from seven sites (47%) were resistant to multiple antibiotics, and the predominant resistance pattern was chlortetracycline–oxytetracycline–tetracycline. Raw sewage isolates from most WWTPs contained
E. coli that exhibited resistance to multiple antibiotics. Cluster analysis indicated that all resistant OR sites had antibiotic resistant isolates that matched AR patterns found in isolates from WWTPs. Similarly, six of the seven sites in BC had AR patterns that matched with resistance patterns in WWTPs. These results suggest that AR testing may be a useful tool for differentiating
E. coli from human and wildlife sources. Further testing of bacterial isolates from known animal sources is necessary to better assess the utility of this approach.
Aptamers can be highly specific for their targets, which implies precise molecular recognition between aptamer and target. However, as small polymers, their structures are more subject to ...environmental conditions than the more constrained longer RNAs such as those that constitute the ribosome. To understand the balance between structural and environmental factors in establishing ligand specificity of aptamers, we examined the RNA aptamer (NEO1A) previously reported as specific for neomycin-B. We show that NEO1A can recognize other aminoglycosides with similar affinities as for neomycin-B and its aminoglycoside specificity is strongly influenced by ionic strength and buffer composition. NMR and 2-aminopurine (2AP) fluorescence studies of the aptamer identified a flexible pentaloop and a stable binding pocket. Consistent with a well-structured binding pocket, docking analysis results correlated with experimental measures of the binding energy for most ligands. Steady state fluorescence studies of 2AP-substituted aptamers confirmed that A16 moves to a more solvent accessible position upon ligand binding while A14 moves to a less solvent accessible position, which is most likely a base stack. Analysis of binding affinities of NEO1A sequence variants showed that the base in position 16 interacts differently with each ligand and the interaction is a function of the buffer constituents. Our results show that the pentaloop provides NEO1A with the ability to adapt to external influences on its structure, with the critical base at position 16 adjusting to incorporate each ligand into a stable pocket by hydrophobic interactions and/or hydrogen bonds depending on the ligand and the ionic environment.
Adult grass shrimp (
Palaemonetes pugio) were exposed to endosulfan or methoprene for 96 h and LC
50 values were calculated. Male and female
P. pugio cohorts were also exposed to endosulfan for 96 h ...in an attempt to determine potential differences in sensitivity between the sexes. Results from the methoprene exposure indicated that this pesticide was not acutely toxic to adult grass shrimp at 1 mg l
−1. Due to the lack of sensitivity, sex specific tests with methoprene were not performed. The calculated LC
50 for a population of grass shrimp, including both males and females exposed to endosulfan, was 0.62 μg l
−1. The LC
50 determinations for the sex specific tests were 0.92 μg l
−1 for males and 1.99 μg l
−1 for females. Following these acute exposures, reproductively active grass shrimp were chronically exposed to 200 ng l
−1 endosulfan or 1 mg l
−1 methoprene and were allowed to produce embryos. The resulting embryos were assessed for potential sublethal toxicity. There were no observed differences in the percent successfully hatching or larval mortality 3-days post hatch among the treatments. However, endosulfan treated embryos had a significantly increased hatching time (9.76 days compared to 8.72 days in controls). Methoprene treated embryos also took longer to hatch (9.55 days), but this delay was not significantly different from controls. These findings suggest that endosulfan may preferentially affect male grass shrimp and exposed female grass shrimp may produce embryos with delayed hatching times.
Toxicity effects of the antifouling compound, Irgarol 1051, were examined using a simulated estuarine salt marsh ecosystem. The 35 day mesocosm exposure incorporated tidal flux and contained ...seawater, sediments, marsh grass, and estuarine biota. Irgarol (10.0 μg/l) caused a significant reduction in phytoplankton biomass and primary productivity. HPLC pigment analysis indicated significant effects of irgarol on both phytoplankton and periphyton community composition, with decreased concentrations of pigments representative of diatom species. There was also a significant decrease in dissolved oxygen levels in the 10.0 μg/l irgarol treatment. Growth of the hard shell clam was significantly reduced in the 1.0 and 10.0 μg/l irgarol treatments. The effects observed occurred at irgarol concentrations greater than those typically measured in the environment. Prolonged exposure, the accumulation of irgarol in sediments, plant, or animal tissues, and the interaction of irgarol with other chemicals in the environment; however, could increase risk.
ABSTRACT
Multiple indicators of water quality, sediment quality, and biological condition were used to assess the status of ecological condition of National Estuarine Research Reserve System (NERRS) ...sites in North Carolina, South Carolina, and Georgia relative to a suite of corresponding scoring criteria. All measurements were made in subtidal aquatic habitats. Calculated scores were integrated into an overall index of habitat quality and used to make comparisons among the various NERR and nonNERR estuaries throughout the region. Sediment quality scores varied considerably among NERR sites, but in most cases were similar between individual NERR and non‐NERR sites in corresponding states. Water quality and biological condition indicators scored consistently higher for NERRs versus non‐NERR sites. Overall habitat quality scores also were consistently higher for NERRS sites, suggesting that these areas are on par with if not in slightly better condition ecologically than neighboring nonNERR estuaries. Portions of individual NERR sites rated as poor with respect to overall habitat quality were limited to relatively small areas (<13% of a reserve's total sampling area). Integr Environ Assess Manag 2015;11:266–275. Published 2014 SETAC. This article is a US Government work and, as such, is in the public domain in the USA.
Key Points
The approach described in this paper provides a method of integrating measurements of multiple indicators of water quality, sediment quality, and biological condition into a single habitat quality index.
The ability to combine a suite of indicators into easily‐interpretable, easy‐to‐understand index represents a powerful management tool.
The results of this study suggest that protected areas such as National Estuarine Research Reserves (NERRs) are in relatively good shape in comparison to neighboring estuaries.
Objective: To examine the effectiveness of respiratory syncytial virus immune globulin administered intravenously (RSV-IGIV) in reducing hospitalization for treatment of RSV in children with ...congenital heart disease (CHD).
Methods: Children younger than 4 years of age were randomly assigned to a treatment group receiving RSV-IGIV, 750 mg/kg, monthly or to a control group not receiving infusions. Surveillance for respiratory tract infections was carried out and management decisions were made by physicians blinded to treatment group.
Results: Hospitalization for treatment of an RSV infection occurred in 32 of 214 (15%) of control children and 21 of 202 (10%) of the children receiving RSV-IGIV, a 31% reduction (
P = .16). However, in infants younger than 6 months of age at study entry, 20 of 82 (24%) in the control group and 10 of 96 (10%) in the RSV-IGIV group had RSV hospitalizations (58% reduction,
P = .01). The incidence of hospitalization for any respiratory tract symptomatology was lower in the RSV-IGIV group (34 of 202, 17%) than in the control group (57 of 214, 27%;
P = .02). There was a significantly higher frequency of unanticipated cyanotic episodes and of poor outcomes after surgery among children with cyanotic CHD in the RSV-IGIV group (22 of 78, 28%) than in the control group (4 of 47, 8.5%;
P = .009).
Conclusion: RSV-IGIV should not be used for prophylaxis of RSV disease in children with cyanotic CHD. RSV-IGIV did not reduce RSV hospitalization in all children with CHD, but it was effective in preventing RSV hospitalization in infants younger than 6 months of age. Further studies in these children are indicated. (J Pediatr 1998;133:492-9)
Background
Vaccination is vital for achieving population immunity to severe acute respiratory syndrome coronavirus 2, but vaccination hesitancy presents a threat to achieving widespread immunity. ...Vaccine acceptance in chronic potentially immunosuppressed patients is largely unclear, especially in patients with asthma. The aim of this study was to investigate the vaccination experience in people with severe asthma.
Methods
Questionnaires about vaccination beliefs (including the Vaccination Attitudes Examination (VAX) scale, a measure of vaccination hesitancy-related beliefs), vaccination side-effects, asthma control and overall safety perceptions following coronavirus disease 2019 (COVID-19) vaccination were sent to patients with severe asthma in 12 European countries between May and June 2021.
Results
660 participants returned completed questionnaires (87.4% response rate). Of these, 88% stated that they had been, or intended to be, vaccinated, 9.5% were undecided/hesitant and 3% had refused vaccination. Patients who hesitated or refused vaccination had more negative beliefs towards vaccination. Most patients reported mild (48.2%) or no side-effects (43.8%). Patients reporting severe side-effects (5.7%) had more negative beliefs. Most patients (88.8%) reported no change in asthma symptoms after vaccination, while 2.4% reported an improvement, 5.3% a slight deterioration and 1.2% a considerable deterioration. Almost all vaccinated (98%) patients would recommend vaccination to other severe asthma patients.
Conclusions
Uptake of vaccination in patients with severe asthma in Europe was high, with a small minority refusing vaccination. Beliefs predicted vaccination behaviour and side-effects. Vaccination had little impact on asthma control. Our findings in people with severe asthma support the broad message that COVID-19 vaccination is safe and well tolerated.
One of the most impacted watersheds in the US in terms of pesticide usage is South Florida, which drains through a series of canals into the Florida Everglades and Florida Bay. Single species ...responses to pesticide exposure are well documented; however, little is known about community level responses to pesticides, especially at lower trophic levels. Microbial assemblages at two sites along the C-111 canal in the Dade County agricultural area in October 1999 (wet season, limited pesticide application) and in February 2000 (dry season, heavy pesticide application) were colonized onto artificial substrates, transported to the laboratory and exposed to atrazine (20 and 200 μg/l), chlorothalonil (2 and 20 μg/l), or endosulfan (1 and 10 μg/l). Structural and functional responses were measured at 24h and 168h post-dose. Regardless of site, season or exposure time, the highest atrazine dose (200 μg/l) significantly reduced chlorophyll a, phototrophic carbon assimilation and bacterial biomass, but stimulated heterotrophic bacterial productivity. Chlorophyll a was also significantly reduced by 20 μg/l atrazine (October only). The lowest endosulfan dose (1 μg/l) significantly increased phototrophic carbon assimilation. The highest chlorothalonil dose (20 μg/l) stimulated heterotrophic bacterial productivity (October only). An overall decrease in the number of protist taxa was observed with all pesticide treatments. Atrazine significantly decreased the relative abundance of chlorophytes and chrysophytes and increased the number of diatom and heterotrophic protist taxa. Chlorothalonil significantly increased the relative abundance of diatoms and chlorophytes, while chrysophytes and heterotrophic protists decreased. Endosulfan also significantly reduced diatom abundance, as well as decreasing the number of chrysophyte, cryptophyte and dinoflagellate taxa. Although previous agricultural pesticide exposure was greater at site C than at site E, the microbial assemblages at site C did not exhibit increased resistance to a subsequent dose of the pesticides.
Grass shrimp (
Palaemonetes pugio) populations exposed to anthropogenic contaminant sources in South Carolina (SC) have reduced densities when compared with populations at SC-reference sites. This ...laboratory study examined the effects of a commonly used agricultural insecticide, endosulfan, on grass shrimp reproduction. Reproductively active grass shrimp were chronically exposed to sublethal concentrations of endosulfan (200 or 400 ng/l) for 43 days. The cumulative number of females that became gravid and the rate at which they became gravid were measured. Endosulfan exposure reduced the cumulative number of gravid females by 31% in the 200 ng/l exposure and 39% in the 400 ng/l exposure. The first appearance of gravid females in the population was significantly delayed in treated populations compared with the control treatment in a dose dependent manner. Clutch size in these gravid females was not significantly different among the treatments. Additionally, there was no difference in the onset of reproduction in the treated populations. These results implicate a population reduction due to a decrease in the overall number of females becoming gravid in a population over time, not a reduction in clutch size per individual. While the mechanisms of action have yet to be defined, these results indicate that sublethal endosulfan concentrations may have a negative effect on grass shrimp reproductive biology.
Freshwater drainage canals in South Florida are utilized to manage water in agricultural, urban, and water conservation areas and, as a result, collect urban and agricultural storm runoff that is ...discharged into the Atlantic Ocean and Gulf of Mexico. Pesticides in this runoff may be toxic to the biota inhabiting these waters. This study evaluated the effects of contaminants in South Florida canals draining into Biscayne Bay on the estuarine grass shrimp (Palaemonetes intermedius), a representative invertebrate species. Results of surface water analysis for pesticides indicated that eight pesticides out of 52 analyzed were detected. The herbicide metolachlor was found at all nine sites in the five canals sampled at concentrations up to 119 ng/L. Atrazine was detected at seven sites at concentrations up to 29 ng/L. Three organophosphate insecticides (chlorpyrifos, malathion, diazinon) were detected at three sites in two canals (Military and North). Grass shrimp from these three sites showed significantly reduced levels of the acetylcholinesterase enzyme as compared to control shrimp. These two canals are similar in the land use areas drained--urban and suburban and agriculture. The results suggest that monitoring organisms for AChE levels can be a means of detecting exposure to organophosphorus pesticide contamination.
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