Tetracycline as a selector for resistant bacteria in activated sludge

Tetracycline, one of the most widely used antibiotics, is excreted into wastewater after consumption by humans and animals. The focus of this research was to evaluate the fate of tetracycline resistant bacteria in the activated sludge process as a function of tetracycline loading. The studies were conducted with aerobic biological sequencing batch reactors (SBRs). When comparing 250 microgl(-1) tetracycline fed SBRs with parallel SBRs having a background influent wastewater tetracycline concentration of approximately 1 microgl(-1), tetracycline fed reactors were found to have increased concentrations and production rates of tetracycline resistant bacteria, higher net growth rates of resistant bacteria, and higher percentages of tetracycline resistant bacteria, which were amplified by increase in organic loading and growth rates.     

Evaluation of manometric respiration tests to assess the effects of veterinary antibiotics in soil

Extensive use of antimicrobials in veterinary medicine results in environmental exposure. Of major concern are microbial effects; including effects on nutrient soil cycles and antibiotic resistance. There is a need to assess the effects of these compounds in the environment. The application of standardized guidelines is relevant in studying many compounds. However there is a lack of special test methods designed for antibiotics. We validate manometric test flasks using glucose and a recalcitrant herbicide. The suitability of these tests for studying antibacterial agents is then investigated using two target functions (aerobic biodegradation and carbon transformation). Compound stability is quantified using HPLC techniques. Effects on total soil respiration in the biodegradation test are immediate and differ significantly from background. We show that compounds do not function as substrates, so effects are due to other soil processes, correlate well to sorption characteristics and are not dose dependent. This test provides details of relative antimicrobial potency towards soil microorganisms and can be used to rank compounds. However the test does not provide details on the nature or extent of specific microbial effects. In contrast, the carbon transformation test is more specific and provides a reproducible indication of dose effect relationships, which is more suitable in assessing the effects of these compounds in the environment. Presently, standard guidelines do not take into account the normal input of antibiotics into soils via contaminated sludge or manure. This should be corrected in future guidelines as these inputs alter microbial composition, organic matter, ionic strength and pH affect sorption and overall impact the test results.     

Use of monitoring data to support conservation management and policy decisions in Micronesia

Adaptive management implies a continuous knowledge‐based decision‐making process in conservation. Yet, the coupling of scientific monitoring and management frameworks remains rare in practice because formal and informal communication pathways are lacking. We examined 4 cases in Micronesia where conservation practitioners are using new knowledge in the form of monitoring data to advance marine conservation. These cases were drawn from projects in Micronesia Challenge jurisdictions that received funding for coupled monitoring‐to‐management frameworks and encompassed all segments of adaptive management. Monitoring in Helen Reef, Republic of Palau, was catalyzed by coral bleaching and revealed evidence of overfishing that led to increased enforcement and outreach. In Nimpal Channel, Yap, Federated States of Micronesia (FSM), monitoring the recovery of marine food resources after customary restrictions were put in place led to new, more effective enforcement approaches. Monitoring in Laolao Bay, Saipan, Commonwealth of the Northern Mariana Islands, was catalyzed by observable sediment loads from poor land‐use practices and resulted in actions that reduced land‐based threats, particularly littering and illegal burning, and revealed additional threats from overfishing. Pohnpei (FSM) began monitoring after observed declines in grouper spawning aggregations. This data led to adjusting marine conservation area boundaries and implementing market‐based size class restrictions. Two themes emerged from these cases. First, in each case monitoring was conducted in a manner relevant to the social and ecological systems and integrated into the decision‐making process. Second, conservation practitioners and scientists in these cases integrated culturally appropriate stakeholder engagement throughout all phases of the adaptive management cycle. More broadly, our study suggests, when describing adaptive management, providing more details on how monitoring and management activities are linked at similar spatial scales and across similar time frames can enhance the application of knowledge.     

The structure of work values: A cross cultural comparison

Several years ago a research project on work values was originated. The study strived to examine the relative importance of work value items and to analyze the structure of the domain for samples from various cultural environments. A facet definition of work values was suggested that provided guidelines for constructing the Work Values Questionnaire and the formulation of hypotheses regarding the structure of relationships among components of work values. Based on data collected from 2280 respondents in eight countries the hypotheses were tested by means of Guttman's Smallest Space Analysis. The results support the hypotheses. An empirical double-ordered conceptual system, a radex structure, was obtained in each of the samples reflecting the facets of the definition: modality of outcome — cognitive, affective and instrumental, and system - performance contingency — reward, resource. In terms of the issue of cultural differences the results indicate the presence of cultural differences in the rating of a limited number of specific values. These differences are only minor variations within a much broader pattern of structural similarity. The fact that essentially the same structure was obtained in eight independent samples lends substantial support to the definitional framework of work values suggested.     

Experience with first trimester prenatal diagnosis of Menkes disease

We have performed 28 first trimester diagnoses for Menkes disease in 27 high risk pregnancies by direct copper measurement on chorionic villi (c.v.) Two male fetuses were found to be affected because of significantly increased copper content. In one male fetus a slightly increased copper content was observed indicating an exogenous copper contamination of the sample. This view was supported by normal results observed after abortion. Three out of 15 diagnostic c.v. samples with a female karyotype showed increased copper levels. In two of these cases, part of the copper content might have been released from the cannulae used for these particular biopsies. Histochemical visualization of copper accumulation in fixed chorionic villi of two affected fetuses and one female fetus was observed. [⁶⁴Cu]-uptake studies have been performed on 11 diagnostic and 10 control c.v. samples. As the control samples in some cases were found to incorporate more [⁶⁴Cu] than the corresponding diagnostic sample, this method cannot at present be used for diagnosis. Compiled results on newborn females gave evidence that two carriers expressed the paternal X-chromosome, and two carriers expressed the maternal X-chromosome in chorionic villi.     

Identification of acetylcholinesterase and cholinesterase in amniotic fluid by immune absorption technique

A method for immunological detection of acetylcholinesterase (AChE) and cholinesterase (ChE) in amniotic fluid is described. By addition of a small amount of antihuman-erythrocyte membrane antibody or anti-pseudocholinesterase antibody to the sample before electrophoresis the two esterase bands on polyacrylamide gel (PAG) can be absorbed away. Similar staining results can also be obtained by specific inhibition of the two esterases with either BW 284C51 (AChE inhibitor) or Lysivane (ChE inhibitor). In cases with a faint AChE band and in cases with blood contamination the immune absorption technique makes interpretation easier. Nearly identical staining results have been obtained by the immune absorption technique and the inhibition technique in the following samples with an AChE band: 34 samples from pregnancies with severe fetal malformation or intrauterine death (2 cases), 4 fetal serum samples, 4 samples of cerebrospinal fluid, 4 samples of fetal erythrolysate and 4 samples of adult erythrolysate. It can be concluded that an antibody prepared against erythrocyte AChE cross-reacts with AChE in cerebrospinal fluid, and that this antibody can be used for demonstration of AChE in amniotic fluid.     

Glial fibrillary acidic protein in amniotic fluids from pregnancies with fetal neural tube defects

The glial fibrillary acidic protein (GFAP) is the subunit protein of intermediate filaments in astrocytes and closely related cell types. By means of an enzyme immunoassay we have determined the concentration of GFAP in amniotic fluids from normal pregnancies and from pregnancies complicated by various fetal malformations. The group of 20 cases of fetal anencephaly had a significantly higher mean amniotic fluid GFAP concentration (115 μg/1±133.6 (S.D.), range 6–378 μg/1) than the control group of 117 normal pregnancies (13 μg/1k±5.5 (S.D.), range 0–31 μg/1), (P<0.001). Two cases of fetal encephalocele likewise had very high amniotic fluid GFAP concentrations. None of the other cases of fetal malformations investigated, including 12 cases of spina bifida, had increased amniotic fluid GFAP concentrations. We conclude that determination of the amniotic fluid GFAP concentration may give additional information in the prenatal diagnosis of fetal nervous system malformations.