Color Perspectives in Aquatic Explorations: Unveiling Innate Color Preferences and Psychoactive Responses in Freshwater Crayfish.

Color preference assay is a test for an animal's innate and adaptive response to differentiate colors and can be used as an endpoint for psychoactive activity evaluation. Several color preference test methods in aquatic animals that can be used to perform behavioral screening have been established. However, the color preference test conditions have yet to be extensively studied and standardized in aquatic invertebrates. This study aimed to replicate and optimize the previously published method to evaluate the potential color preference in freshwater crayfish based on four different approaches: species, life stages, sex, and pharmaceutical exposure. Using the optimized setup, two crayfish species display color preferences to some specific colors. P. clarkii displays more dominant color preference behavior than C. quadricarinatus in terms of color preference ranking and index. P. clarkii prefers the red color compared to other colors (red > green > blue > yellow), while C. quadricarinatus dislikes yellow compared to other colors (blue = green = red > yellow). Since P. clarkii has a more obvious color index ranking and several advantages compared to C. quadricarinatus, we conducted further tests using P. clarkii as an animal model. In the juvenile and adult stages of P. clarkii, they prefer red and avoid yellow. However, the juvenile one did not display a strong color preference like the adult one. Different sex of crayfish displayed no significant differences in their color preference responses. In addition, we also evaluated the potential effect of the antidepressant sertraline on color preference in P. clarkii and found that waterborne antidepressant exposure can significantly alter their color preference. This fundamental information collected from this study supports the crayfish color preference test as a good behavioral test to address environmental pollution.

OpenBloodFlow: A User-Friendly OpenCV-Based Software Package for Blood Flow Velocity and Blood Cell Count Measurement for Fish Embryos.

The transparent appearance of fish embryos provides an excellent assessment feature for observing cardiovascular function in vivo. Previously, methods to conduct vascular function assessment were based on measuring blood-flow velocity using third-party software. In this study, we reported a simple software, free of costs and skills, called OpenBloodFlow, which can measure blood flow velocity and count blood cells in fish embryos for the first time. First, videos captured by high-speed CCD were processed for better image stabilization and contrast. Next, the optical flow of moving objects was extracted from the non-moving background in a frame-by-frame manner. Finally, blood flow velocity was calculated by the Gunner Farneback algorithm in Python. Data validation with zebrafish and medaka embryos in OpenBloodFlow was consistent with our previously published ImageJ-based method. We demonstrated consistent blood flow alterations by either OpenBloodFlow or ImageJ in the dorsal aorta of zebrafish embryos when exposed to either phenylhydrazine or ractopamine. In addition, we validated that OpenBloodFlow was able to conduct precise blood cell counting. In this study, we provide an easy and fully automatic programming for blood flow velocity calculation and blood cell counting that is useful for toxicology and pharmacology studies in fish.

Physiological Effects of Neonicotinoid Insecticides on Non-Target Aquatic Animals-An Updated Review.

In this paper, we review the effects of large-scale neonicotinoid contaminations in the aquatic environment on non-target aquatic invertebrate and vertebrate species. These aquatic species are the fauna widely exposed to environmental changes and chemical accumulation in bodies of water. Neonicotinoids are insecticides that target the nicotinic type acetylcholine receptors (nAChRs) in the central nervous systems (CNS) and are considered selective neurotoxins for insects. However, studies on their physiologic impacts and interactions with non-target species are limited. In researches dedicated to exploring physiologic and toxic outcomes of neonicotinoids, studies relating to the effects on vertebrate species represent a minority case compared to invertebrate species. For aquatic species, the known effects of neonicotinoids are described in the level of organismal, behavioral, genetic and physiologic toxicities. Toxicological studies were reported based on the environment of bodies of water, temperature, salinity and several other factors. There exists a knowledge gap on the relationship between toxicity outcomes to regulatory risk valuation. It has been a general observation among studies that neonicotinoid insecticides demonstrate significant toxicity to an extensive variety of invertebrates. Comprehensive analysis of data points to a generalization that field-realistic and laboratory exposures could result in different or non-comparable results in some cases. Aquatic invertebrates perform important roles in balancing a healthy ecosystem, thus rapid screening strategies are necessary to verify physiologic and toxicological impacts. So far, much of the studies describing field tests on non-target species are inadequate and in many cases, obsolete. Considering the current literature, this review addresses important information gaps relating to the impacts of neonicotinoids on the environment and spring forward policies, avoiding adverse biological and ecological effects on a range of non-target aquatic species which might further impair the whole of the aquatic ecological web.

Acute and Sub-Chronic Exposure to Artificial Sweeteners at the Highest Environmentally Relevant Concentration Induce Less Cardiovascular Physiology Alterations in Zebrafish Larvae.

Artificial sweeteners are widely used food ingredients in beverages and drinks to lower calorie intake which in turn helps prevent lifestyle diseases such as obesity. However, as their popularity has increased, the release of artificial sweetener to the aquatic environment has also increased at a tremendous rate. Thus, our study aims to systematically explore the potential cardiovascular physiology alterations caused by eight commercial artificial sweeteners, including acesulfame-K, alitame, aspartame, sodium cyclamate, dulcin, neotame, saccharine and sucralose, at the highest environmentally relevant concentration on cardiovascular performance using zebrafish (Danio rerio) as a model system. Embryonic zebrafish were exposed to the eight artificial sweeteners at 100 ppb and their cardiovascular performance (heart rate, ejection fraction, fractional shortening, stroke volume, cardiac output, heartbeat variability, and blood flow velocity) was measured and compared. Overall, our finding supports the safety of artificial sweetener exposure. However, several finding like a significant increase in the heart rate and heart rate variability after incubation in several artificial sweeteners are noteworthy. Biomarker testing also revealed that saccharine significantly increase the dopamine level in zebrafish larvae, which is might be the reason for the cardiac physiology changes observed after saccharine exposure.

Interspecies Behavioral Variability of Medaka Fish Assessed by Comparative Phenomics.

Recently, medaka has been used as a model organism in various research fields. However, even though it possesses several advantages over zebrafish, fewer studies were done in medaka compared to zebrafish, especially with regard to its behavior. Thus, to provide more information regarding its behavior and to demonstrate the behavioral differences between several species of medaka, we compared the behavioral performance and biomarker expression in the brain between four medaka fishes, Oryzias latipes, Oryzias dancena, Oryzias woworae, and Oryzias sinensis. We found that each medaka species explicitly exhibited different behaviors to each other, which might be related to the different basal levels of several biomarkers. Furthermore, by phenomics and genomic-based clustering, the differences between these medaka fishes were further investigated. Here, the phenomic-based clustering was based on the behavior results, while the genomic-based clustering was based on the sequence of the nd2 gene. As we expected, both clusterings showed some resemblances to each other in terms of the interspecies relationship between medaka and zebrafish. However, this similarity was not displayed by both clusterings in the medaka interspecies comparisons. Therefore, these results suggest a re-interpretation of several prior studies in comparative biology. We hope that these results contribute to the growing database of medaka fish phenotypes and provide one of the foundations for future phenomics studies of medaka fish.

Exploiting the Freshwater Shrimp Neocaridina denticulata as Aquatic Invertebrate Model to Evaluate Nontargeted Pesticide Induced Toxicity by Investigating Physiologic and Biochemical Parameters.

As a nicotinoid neurotoxic insecticide, imidacloprid (IMI) works by disrupting nerve transmission via nicotinic acetylcholine receptor (nAChR). Although IMI is specifically targeting insects, nontarget animals such as the freshwater shrimp, Neocaridina denticulata, could also be affected, thus causing adverse effects on the aquatic environment. To investigate IMI toxicity on nontarget organisms like N. denticulata, their physiology (locomotor activity, heartbeat, and gill ventilation) and biochemical factors (oxidative stress, energy metabolism) after IMI exposure were examined. IMI exposure at various concentrations (0.03125, 0.0625, 0.125, 0.25, 0.5, and 1 ppm) to shrimp after 24, 48, 72 h led to dramatic reduction of locomotor activity even at low concentrations. Meanwhile, IMI exposure after 92 h caused reduced heartbeat and gill ventilation at high concentrations. Biochemical assays were performed to investigate oxidative stress and energy metabolism. Interestingly, locomotion immobilization and cardiac activity were rescued after acetylcholine administration. Through molecular docking, IMI demonstrated high binding affinity to nAChR. Thus, locomotor activity and heartbeat in shrimp after IMI exposure may be caused by nAChR blockade and not alterations caused by oxidative stress and energy metabolism. To summarize, N. denticulata serves as an excellent and sensitive aquatic invertebrate model to conduct pesticide toxicity assays that encompass physiologic and biochemical examinations.

Cardiovascular Performance Measurement in Water Fleas by Utilizing High-Speed Videography and ImageJ Software and Its Application for Pesticide Toxicity Assessment.

Water fleas are a good model for ecotoxicity studies, and were proposed for this purpose by the United States Environmental Protection Agency, due to their easy culture, body transparency, and high sensitivity to chemical pollution. Cardiovascular function parameters are usually used as an indicator of toxicity evaluation. However, due to the nature of the heart and blood flow, and the speed of the heartbeat, it is difficult to perform precise heartbeat and blood flow measurements with a low level of bias. In addition, the other cardiovascular parameters, including stroke volume, cardiac output, fractional shortening, and ejection fraction, have seldom been carefully addressed in previous studies. In this paper, high-speed videography and ImageJ-based methods were adopted to analyze cardiovascular function in water fleas. The heartbeat and blood flow for three water flea species, Daphnia magna, Daphnia silimis, and Moina sp., were captured by high-speed videography and analyzed using open-source ImageJ software. We found the heartbeat is species-dependent but not size-dependent in water fleas. Among the three water fleas tested, D. magna was identified as having the most robust heartbeat and blood flow rate, and is therefore suitable for the ecotoxicity test. Moreover, by calculating the diameter of the heart, we succeeded in measuring other cardiovascular parameters. D. magna were challenged with temperature changes and a pesticide (imidacloprid) to analyze variations in its cardiovascular function. We found that the heartbeat of D. magna was temperature-dependent, since the heartbeat was increasing with temperature. A similar result was shown in the cardiac output parameter. We also observed that the heartbeat, cardiac output, and heartbeat regularity are significantly reduced when exposed to imidacloprid at a low dose of 1 ppb (parts per billion). The blood flow rate, stroke volume, ejection fraction, and fractional shortening, on the contrary, did not display significant changes. In conclusion, in this study, we report a simple, highly accurate, and cost-effective method to perform physiological and toxicological assessments in water fleas.

Multiple Screening of Pesticides Toxicity in Zebrafish and Daphnia Based on Locomotor Activity Alterations.

Pesticides are widely used to eradicate insects, weed species, and fungi in agriculture. The half-lives of some pesticides are relatively long and may have the dire potential to induce adverse effects when released into the soil, terrestrial and aquatic systems. To assess the potential adverse effects of pesticide pollution in the aquatic environment, zebrafish (Danio rerio) and Daphnia magna are two excellent animal models because of their transparent bodies, relatively short development processes, and well-established genetic information. Moreover, they are also suitable for performing high-throughput toxicity assays. In this study, we used both zebrafish larvae and water flea daphnia neonates as a model system to explore and compare the potential toxicity by monitoring locomotor activity. Tested animals were exposed to 12 various types of pesticides (three fungicides and 9 insecticides) for 24 h and their corresponding locomotor activities, in terms of distance traveled, burst movement, and rotation were quantified. By adapting principal component analysis (PCA) and hierarchical clustering analysis, we were able to minimize data complexity and compare pesticide toxicity based on locomotor activity for zebrafish and daphnia. Results showed distinct locomotor activity alteration patterns between zebrafish and daphnia towards pesticide exposure. The majority of pesticides tested in this study induced locomotor hypo-activity in daphnia neonates but triggered locomotor hyper-activity in zebrafish larvae. According to our PCA and clustering results, the toxicity for 12 pesticides was grouped into two major groups based on all locomotor activity endpoints collected from both zebrafish and daphnia. In conclusion, all pesticides resulted in swimming alterations in both animal models by either producing hypo-activity, hyperactivity, or other changes in swimming patterns. In addition, zebrafish and daphnia displayed distinct sensitivity and response against different pesticides, and the combinational analysis approach by using a phenomic approach to combine data collected from zebrafish and daphnia provided better resolution for toxicological assessment.

Mathematical modeling suggests high potential for the deployment of floating photovoltaic on fish ponds.

Rising energy needs and pressure to reduce greenhouse gas emissions have led to a significant increase in solar power projects worldwide. Recently, the development of floating photovoltaic (FPV) systems offers promising opportunities for land scarce areas. We present a dynamic model that simulates the main biochemical processes in a milkfish (Chanos chanos) pond subject to FPV cover. We validated the model against experimental data collected from ponds with and without cover during two production seasons (winter and summer) and used it to perform a Monte-Carlo analysis of the ecological effects of different extents of cover. Our results show that the installation of FPV on fish ponds may have a moderate negative impact on fish production, due to a reduction in dissolved oxygen levels. However, losses in fish production are more than compensated by gains in terms of energy (capacity of around 1.13 MW/ha). We estimated that, with approximately 40,000 ha of aquaculture ponds in Taiwan, the deployment of FPV on fish ponds in Taiwan could accommodate an installed capacity more twice as high as the government's objective of 20 GW solar power by 2025. We argue that the rules and regulations pertaining to the integration of FPV on fish ponds should be updated to allow realizing the full potential of this new green technology.

Effects of sunlight, microbial activity, and temperature on the declines of antibiotic lincomycin in freshwater and saline aquaculture pond waters and sediments.

The residues of lincomycin (LIN), an antibiotic administered to aquatic animals, are often detected in aquatic environments. This study investigated effects of three environmental factors, sunlight, microbial activity, and temperature, on declines of spiked LIN in waters and sediment slurry samples collected from freshwater tilapia (Oreochromis mossambicus) and marine shrimp (Litopenaeus vannamei) culture ponds. The results showed that sunlight, temperature, and microbial activity all accelerated LIN transformation in the water and slurry samples. In matrixes of all water and slurry samples, LIN transformation was significantly faster under light conditions [half-life (t1/2) = 24-53 days] than under dark conditions (t1/2 = 154-2897 days). Microbial activity also accelerated LIN transformation; the t1/2 of LIN was shorter after nonsterile treatment (t1/2 = 12-809 days) than after sterile treatment (t1/2 = 154-2897 days). Moreover, LIN transformation was faster at 28 °C (t1/2 = 18-38 days) than at 20 and 12 °C (t1/2 = 34 and 462 days, respectively) in both slurry samples. The results revealed that LIN transformation in aquaculture pond water and sediment was either slow or stagnant. Sunlight, microbial activity, and temperature can accelerate LIN transformation to reduce LIN residue levels.

Development and assays estradiol equivalent concentration from prawn (p-EEQ) in river prawn, Macrobrachium nipponense, in Taiwan.

The present study established a fast and convenient bioassay method for aqueous ecosystems using the prawn estradiol equivalent concentration (p-EEQ) of male Macrobrachium nipponense, which produce vitellogenin (VTG) after exposure to xeno-estrogens. This method was then used to determine the concentrations of xeno-estrogen pollutants in the rivers of Taiwan. To establish the calibration curve for the concentrations based on the p-EEQ, the induced VTG content was determined using the alkali-labile phosphate method after male M. nipponense were exposed to 0, 10, 100, 1,000 and 10,000ng/L of 17ß-estradiol for 1, 3, 5, 7, 10 and 14 days, respectively. The results of the experiments showed that the induced VTG content in all of the experimental groups stabilized after 10 days, except for the 10,000ng/L experimental group, in which the induced VTG content decreased after 10 days. A 17ß-estradiol-VTG10day response curve was then established based on the induced VTG content in the 0, 10, 100 and 1000ng/L experimental groups at day 10. After establishing the curve, male M. nipponense were captured from the upper, middle and lower reaches of the Chuo-shui River, the Beigang River, the Jishui River, the Agongdian River and the Sichong River in Taiwan, and the VTG content in these prawns was determined. In addition, the p-EEQ in the waters was determined based on the VTG content, and the estradiol equivalent concentration (EEQ) in the waters was also measured immediately after sampling using the solid-phase extraction-enzyme-linked immunosorbent assay (SPE-ELISA) method. The results showed that the p-EEQ in the middle and lower reaches of the rivers in certain parts of Taiwan ranged from 38 to 400ng/L, and the detection rate was 100%. Moreover, the EEQ ranged from 7.9 to 92.9ng/L, and the detection rate was 42.9%, indicating that most of the middle and lower reaches of the rivers in Taiwan were polluted by xeno-estrogens. The 17ß-estradiol concentrations determined based on the p-EEQ were all higher than those based on the EEQ (SPE-ELISA method). The results of the present study showed that the use of M. nipponense to determine the p-EEQ in environmental waters provided advantages that included a high detection rate, high sensitivity and convenience. However, the p-EEQ cannot be used in waters that do not contain M. nipponense.

Residue Depletion Study of Danofloxacin in Cultured Tilapia (Oreochromis mossambicus).

Danofloxacin is an antibacterial drug of the fluoroquinolone group developed for therapeutic purposes in veterinary medicine. The studies described here include investigations of the residues following a single dose or multiple doses of danofloxacin. Residue depletion studies were performed to determine residues in plasma and tissues of saltwater tilapia fish (Oreochromis mossambicus) after a single oral administration of danofloxacin at the dose of 10 mg/kg body weight and also after daily dose of 10 mg/kg body weight for five consecutive days. Danofloxacin residues were analyzed by HPLC with fluorescence detection. Following a single oral dose, danofloxacin residues in 6 h postdosing tilapia were at a maximum of 1.44, 12.48, and 13.18 µg/g in serum, liver, and kidney samples, respectively, while a peak muscle concentration of 2.15 µg/g was reached at 12 h. From single-dose data, the concentration of danofloxacin in serum, muscle, liver, and kidney samples declined with half-lives of 29, 34, 49, and 44 h, respectively. Based on the maximum residue level (MRL) of 0.1 µg/g in edible tissue for fin fish, the withdrawal times of danofloxacin in muscle were estimated to fall below the MRL after a withdrawal period of 21 days following the multiple-dose administration. These results may be helpful to regulatory agencies as they determine what tissues should be monitored to ensure that the established residue safety tolerance levels are not exceeded.

Toxicity of the veterinary sulfonamide antibiotic sulfamonomethoxine to five aquatic organisms.

The purpose of this study was to investigate the acute and chronic toxicity of sulfamonomethoxine (SMM) to aquatic organisms to evaluate its impact at different trophic levels in the ecosystem. Regarding the growth inhibition of microalgae, SMM exhibited 72-h median effective concentration (EC50) values of 5.9mgL(-1) for freshwater Chlorella vulgaris and 9.7mgL(-1) for marine Isochrysis galbana. In a study on the cladocerans, SMM exhibited acute toxicity and 48-h median lethal concentrations of 48mgL(-1) for Daphnia magna and 283mgL(-1) for D. similis. An examination of chronic toxicity revealed that SMM inhibited the brook production of the cladocerans and exhibited 21-day EC50 values of 14.9mgL(-1) for D. magna and 41.9mgL(-1) for D. similis. This study investigated the potentially adverse effects of SMM on aquatic organisms and revealed that microalgae exhibited higher sensitivity to SMM than cladocerans did. The residue of SMM in water is recommended to be carefully evaluated to reduce ecological impacts after applied to cultured animals.

Application parameters of laccase-mediator systems for treatment of sulfonamide antibiotics.

This is the first study to examine the application parameters for oxidation of two sulfonamide antibiotics (SAs), sulfadimethoxine (SDM) and sulfamonomethoxine (SMM), using a novel laccase and mediators. The optimal conditions in the laccase-mediator system (LMS) were pH 4, 50-60 °C, and 1 mM for 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS); pH 4, 40-60 °C, and 1 mM for violuric acid (VLA); pH 6, 50 °C, and 2 mM for syringaldehyde (SIR). Additionally, the conditions of the 4-hydroxybenzyl alcohol (HBA) mediator were pH 4, 30 °C, and 2 mM in the oxidation of SDM; and the temperature increased to 60 °C for SMM. The laccase coupled with VLA and HBA resulted in the lowest toxicity of the SA solutions during processing, whereas treatments with ABTS and SIR resulted in higher toxicities. Furthermore, the laccase used in this study was stable and resistant to dialysis, thus can be reused for oxidation process.

The implication of mediators for enhancement of laccase oxidation of sulfonamide antibiotics.

In this study, the transformation of sulfonamide antibiotics (SAs, 50 mg L(-1)) was investigated in systems consisting of a fungal laccase (6 IU) and six mediators (1mM). The results illustrate that the laccase had limited effect on the removal of sulfadimethoxine and sulfamonomethoxine. However, laccase oxidation with the mediators (LMS) led to significant declines of the SAs. Two mediators, 2-2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) and violuric acid, provided the fastest transformations of SAs in LMS, with t(1/2)s of 1.8-4.1 min; slower transformations in syringaldehyde and 4-hydroxybenzyl alcohol, with t(1/2)s of 19.0-131 min; and the slowest or no significant decline in 4-hydroxyacetophenone and 4-cyanophenol, with t(1/2)s > 330 min. The decline of the re-added SAs in LMS was slower than that of the first addition. De-aniline and oxidative coupling are the two detectable pathways for the transformation of SAs. The results indicated that some mediators enhanced laccase oxidation of the SAs.

Implication of light sources and microbial activities on degradation of sulfonamides in water and sediment from a marine shrimp pond.

In this study, the effects of natural, visible and ultraviolet lights, microbial activities and aerobic and anaerobic conditions on degradation of four different sulfonamide antibiotics (SAs) were studied. Water and sediment collected from a marine shrimp pond were examined and a factorial design was employed to evaluate the effects of selected parameters. The results showed that all the SAs in water and sediment had significant declines attributed to natural light and microbial activities. The half-lives (t(1/2s)) of SAs in non-sterile water and sediment samples under natural light were 2.0-15.0 and 0.7-7.3 days, respectively, and slowed to 2.9-62.9 and 6.9-85.6 days after sterilized. Moreover, the declines of SAs were significantly faster under ultraviolet than visible light with 36.5-70.9% shorter t(1/2)s. Anaerobic condition was also effective on declines of SAs in sediment. Both sulfate-reducing and methanogenic microbes were directly involved in the decline of SDM, and indirectly contributed to SMX declines.

Effects of light regime and oxygen profile on transformation of oxolinic acid in pond sediment.

This study investigated the effects of light (visible light - 5800 lux, 24h) or dark regime and aerobic or anaerobic condition on the decay of added oxolinic acid (OA) at 5, 10 and 20 mg L(-1) in eel pond sediment. An asymptotic decaying exponential model C(t)=C(min)+C(o) × exp (-k × t) was used to facilitate quantitative approach to OA transformation, where C(t) is the concentration of OA after t days, C(min) the estimated level-off concentration of OA residue, C(o) the concentration of added OA and k the decaying coefficient. OA decayed faster under light (C(min)=4.6 mg L(-1)) than under dark (C(min)=7.8 mg L(-1)) and also decayed faster under aerobic (C(min)=4.0 mg L(-1)) than under anaerobic condition (C(min)=8.5 mg L(-1)). C(min) increased with C(o). Sundrying and tilling eel pond bottom should be able to reduce OA residue significantly.

Effects of light and microbial activity on the degradation of two fluoroquinolone antibiotics in pond water and sediment.

Enrofloxacin (ENR) and ciprofloxacin (CIP) are two fluoroquinolone (FQ) antibiotics widely used to treat diseases of human beings and cultured animals. These two FQs are usually detected in the effluent of municipal sewage plants and related aquatic environments. The purpose of this study was to understand the fates of ENR and CIP in aquaculture pond water and a sediment slurry in a laboratory-scale experiment. Effects of light and microbial activity on the degradation of these two FQs were investigated. Results indicated that natural irradiation plays a major role in the degradation of ENR and CIP in pond water and the sediment slurry. The 50 % dissipation times (DT(50)) with non-sterile treatment were 0.01 and 18.4 d for ENR, and 0.04 and 17.3 d for CIP in the water and sediment slurry, respectively. On the other hand, the degradation of ENR and CIP under dark conditions was slow or even hindered, and all of their DT(50) values exceeded 100 d. These two FQs degraded faster in the sediment slurry than in pond water under dark conditions. Artificial ultraviolet (UV) and fluorescence light had similar effects on the degradation of ENR in the pond water and sediment slurry. Degradation of CIP was faster with UV than with fluorescence light treatment, while no such difference was found for ENR degradation. CIP was a degradation product of ENR under both light and dark conditions, and DT(50) values for both compounds were shorter in the presence of light. The phenomenon of biodegradation was observed during degradation of CIP in the sediment slurry under natural light.

Difference in the regulation of IL-8 expression induced by uropathogenic E. coli between two kinds of urinary tract epithelial cells.

Bacterial adherence to epithelial cells is a key virulence trait of pathogenic bacteria. The type 1 fimbriae and the P-fimbriae of uropathogenic Escherichia coli (UPEC) have both been described to be important for the establishment of urinary tract infections (UTI). To explore the interactions between the host and bacterium responsible for the different environments of UPEC invasion, we examined the effect of pH and osmolarity on UPEC strain J96 fimbrial expression, and subsequent J96-induced interleukin-8 (IL-8) expression in different uroepithelial cells. The J96 strain grown in high pH with low osmolarity condition was favorable for the expression of type 1 fimbriae; whereas J96 grown in low pH with high osmolarity condition was beneficial for P fimbriae expression. Type 1 fimbriated J96 specifically invaded bladder 5637 epithelial cells and induced IL-8 expression. On the contrary, P fimbriated J96 invaded renal 786-O epithelial cells and induced IL-8 expression effectively. Type 1 fimbriated J96-induced IL-8 induction involved the p38, as well as ERK, JNK pathways, which leads to AP-1-mediated gene expression. P fimbriated J96-induced augmentation of IL-8 expression mainly involved p38-mediated AP-1 and NF-kappaB transcriptional activation. These results indicate that different expression of fimbriae in J96 trigger differential IL-8 gene regulation pathways in different uroepithelial cells.

Degradation of oxolinic acid and flumequine in aquaculture pond waters and sediments.

Oxolinic acid (OA) and flumequine (FLU) are two of the quinolone antibiotics (QAs) that are widely used in aquaculture. The purpose of this study was to understand the fates of OA and FLU in waters and sediment slurries from aquaculture ponds in a laboratory experiment. Waters and sediments were sampled from an eel (Anguilla japonica) pond and a shrimp (Penaeus vannamei) pond. The effects of light, microbial activities, and temperature on the degradation of these two QAs were elucidated. Results indicated that light plays a major role in the degradation of OA and FLU in waters and sediment slurries. Under illuminated and non-sterile conditions, the half-lives (t(1/2)) of OA were 2.3-4.8 and 9.5-15.0 days in the waters and sediment slurries, respectively. For FLU, under the same conditions, t(1/2) values were 1.9-2.3 and 3.6-6.4 days, respectively. Photodegradation of OA and FLU was much faster in water than in sediment slurry. In both environments, degradation became very slow or would plateau after only minimal change in the dark. Besides the effect of light, biodegradation had very minor effects on the degradation of the two QAs in the sediment slurries. The only independent biodegradation was found when OA was placed in shrimp pond sediment slurry, but at a much lower rate (t(1/2) of 98.7 days) than in light. Biodegradation of FLU was also found in the eel pond sediment slurry but only through an additional connection with light. Also, re-addition enhanced the degradation of OA in shrimp pond sediment slurry, but slowed the degradation of FLU in the eel pond sediment slurry in the dark. The temperature experiment in this study showed no significant effects on degradation of the two QAs in either pond waters or sediment slurries.