Mechanistic approach of tannery wastewater and sulfadiazine mutual toxicity in wheat (Triticum aestivum L.) and mitigation through exogenous application of gallic acid

Excessive release of chromium (Cr) from the tanning industry and antibiotics from livestock caused severe hazards to humans. Gallic acid (GA 10 mM) alleviated alone/combined SDZ 30 mg kg-1 and TWW 40, 60, and 100% stress in wheat. GA (10 mM) decreased the TSP 12 and 13%, TFAA 8 and 10%, TSS 14 and 16%, RS 18 and 16%, and NRS 11 and 9% in shoots and grains under SDZ + TWW (30 mg kg-1+100%), compared without foliar. GA (10 mM) declined the MDA 20 and 31, EL 13 and 36%, H2O2 17 and 15%, O2•- 10 and 11% in leaves and roots, under combined SDZ + TWW (30 mg kg-1+100%), compared without foliar. GA (10 mM) improved the POD 106 and 30%, SOD 145 and 31%, CAT 78, and 35%, APX 100 and 25% in leaves and roots under combined SDZ + TWW (30 mg kg-1+100%), compared without foliar application. Considerably GA (10 mM) reduced total Cr 18, CrIII 20, and CrVI 50% in roots and shoots 19, 41, and 48%, and grains 15, 27, and 29% respectively, under combined SDZ + TWW (30 mg kg-1+100%) stress, compared without foliar. Overall, GA boosted the wheat growth, physiology, and defence system by inhibiting the combined SDZ + Cr toxicity.

Tetracycline and sulfadiazine toxicity in human liver cells Huh-7

As typical antibiotics, tetracycline (TC) and sulfadiazine (SDZ) enter the human body through the food chain. Therefore, it is necessary to understand their individual and combined toxicity. In this study, the effects of TC, SDZ, and their mixture on cell viability, cell membrane damage, liver cell damage, and oxidative damage were evaluated in in vitro assays with human liver cells Huh-7. The results showed cytotoxicity of TC, SDZ, and their mixture, which induced oxidative stress and caused membrane and cell damage. The effect of antibiotics on Huh-7 cells increased with increasing concentration, except for lactate dehydrogenase (LDH) activity that commonly showed a threshold concentration response and cell viability, which commonly showed a biphasic trend, suggesting the possibility of hormetic responses where proper doses are included. The toxicity of TC was commonly higher than that of SDZ when applied at the same concentration. These findings shed light on the individual and joint effects of these major antibiotics on liver cells, providing a scientific basis for the evaluation of antibiotic toxicity and associated risks.

The different toxicological effects and removal efficiencies of norfloxacin and sulfadiazine in culturing Arthrospira (Spirulina) platensis

Norfloxacin (NFX) and sulfadiazine (SDZ) are two widely used antibiotics belonging to fluoroquinolone and sulfonamide groups, respectively, and have become the commonly detected micropollutants in aquatic environments. However, only few works have been conducted to investigate the highly probable inhibition of these antibiotic pollutants to Arthrospira platensis, which is an important species of cyanobacteria that is one of primary producers in aquatic ecosystems and should be remarkably sensitive to environmental pollutants due to its prokaryotic characteristics. Hence, the toxicological effects and removal efficiencies of NFX and SDZ in culturing A. platensis were studied by analyzing the biomass growth, photosynthetic pigments, primary biocomponents, and antibiotics concentration. The corresponding variations of these characteristics showed the higher sensitivity of A. platensis to NFX than to SDZ, indicating the specifically targeted effect of NFX on A. platensis, which could be confirmed in silico by the higher binding affinity of NFX with the critical enzyme. The obtained results illustrated the roles of NFX and SDZ on the growth of A. platensis, thus providing the great support in employing A. platensis to reduce hazards from contaminated water and recover biomass resources.

Response of submerged macrophytes and leaf biofilms to different concentrations of oxytetracycline and sulfadiazine

Oxytetracycline and sulfadiazine were widely used and they entered the environment through various channels such as domestic sewage, medical wastewater and agricultural wastewater, causing significant ecological risk. To determine the effects of different antibiotic concentrations on submerged macrophytes, Vallisneria natans was exposed to solutions containing different concentrations of oxytetracycline and sulfadiazine (0.1 mg/L、1 mg/L、10 mg/L、50 mg/L). After 20-days exposure, we found that 10 mg/L groups had a significant effect on Vallisneria natans. Under high antibiotic concentrations, the growth of Vallisneria natans was inhibited, chloroplasts were deformed, the chlorophyll content was reduced, and antioxidant enzyme activities, such as superoxide dismutase and glutathione, were increased. There was no significant difference between the control group and groups with low antibiotic concentrations (≤1 mg/L). The N-acyl-l-homoserine lactone concentration tended to increase with increasing antibiotic concentrations. The presence of antibiotics also affected the microbial community structure of biofilms on the submerged macrophytes. For example, the higher the concentration of antibiotics, the higher the proportion of Proteobacteria. These results suggest that high concentrations of oxytetracycline and sulfadiazine can disrupt homeostasis, induce effective Vallisneria natans defense mechanisms and alter biofilms in aquatic ecosystems.

Insights into the mechanism of the interference of sulfadiazine on soil microbial community and function

The accumulation of sulfonamides in the soil environment possessed the potential to change soil microbial community and function. Metabolomics is capable of providing insights into the carbon metabolic pool and molecular mechanisms associated with external stressors. Here we evaluated alternations in soil bacterial community and soil metabolites profiles under sulfadiazine (SDZ) exposure and proposed a potential mechanism that SDZ accumulation in soil affected soil organic matter (SOM) cycling. Sequencing analysis showed that the relative abundance of bacterial species associated with carbon cycling significantly decreased under high concentrations of SDZ exposure. Untargeted metabolomics analysis showed that 78 metabolites were significantly changed with the presence of SDZ in soil. The combination of functional predictions and pathway analysis both demonstrated that high concentrations of SDZ exposure could cause disturbance in anabolism and catabolism. Moreover, the noticeable decline in the relative content of carbohydrates under high concentrations of SDZ exposure might weaken physical separation and provide more chances for microbes to degrade SOM. The above results provided evidence that SDZ accumulation in soil held the potential to disturb SOM cycling. These findings spread our understanding about the environmental risk of antibiotic in the soil environment beyond the dissemination of antibiotic resistance.

The effect of bio/organic fertilizers on the phytotoxicity of sulfadiazine to Echium amoenum in a calcareous soil

The fate of antibiotics and their effects on plant growth may be changed by the application of fertilizers. The present study was carried out to investigate the effect of sulfadiazine (SDZ), rice husk compost (RHC), rice husk biochar (RHB), and mycorrhiza (MR) on the growth attributes of Iranian Echium amoenum Fisch & C.A. Mey. A greenhouse experiment as a completely randomized design with six treatments of bio/organic-fertilizers (no bio-fertilizer (NF), RHB, RHC, MR, RHB+MR, and RHC+MR) and three levels of SDZ application (0, 100, and 200 mg kg^-1) was performed for 7months with three replicates. Shoot and root SDZ concentrations were determined using high-pressure liquid chromatography-diode array detection (HPLC-DAD) instrumentation. The results revealed that the application of RHC, RHB, and MR had a significant impact on the reduction of the toxicity effects of SDZ on plant properties. The lowest values of growth parameters belonged to the 200 mg kg^-1 of SDZ with no bio-fertilizers, while the highest growth parameters were observed in the treatments of RHB+MR, and RHC+MR with no SDZ application. Also, chlorophyll pigments content was affected by used treatments and the lowest rates of chlorophyll a (4.24), chlorophyll b (2.99), and carotenoids (2.88) were related to the 200 mg kg^-1 of SDZ with no biofertilizers application. The co-application of bio-fertilizers and SDZ (at both levels of 100 and 200 mg kg^-1) decreased SDZ uptake by both shoot and root in comparison with the control. The same results were obtained with macro (NPK) and micro (Fe, Zn, Cu, and Mn) nutrients uptake by the shoot in which the lowest values of nutrients uptake were observed in treatment of 200 mg kg^-1 of SDZ with no bio-fertilizers. Furthermore, in the case of the effect of the used treatments on root colonization, the results showed that the lowest value (7.26%) belonged to the 200 mg kg^-1 application of SDZ with no bio-fertilizers. Generally, this study demonstrated that bio-fertilizers could be considered as an effective strategy in controlling the negative effects of antibiotics on the growth properties and nutrients status of the plants grown in such contaminated soils.

The Toxicity Exerted by the Antibiotic Sulfadiazine on the Growth of Soil Bacterial Communities May Increase over Time

The toxicity exerted by the antibiotic sulfadiazine on the growth of soil bacterial communities was studied in two agricultural soils for a period of 100 days. In the short-term (2 days of incubation), the effect of sulfadiazine on bacterial growth was low (no inhibition or inhibition <32% for a dose of 2000 mg·kg-1). However, sulfadiazine toxicity increased with time, achieving values of 40% inhibition, affecting bacterial growth in both soils after 100 days of incubation. These results, which were here observed for the first time for any antibiotic in soil samples, suggest that long-term experiments would be required for performing an adequate antibiotics risk assessment, as short-term experiments may underestimate toxicity effects.

A proteomic and biochemical investigation on the effects of sulfadiazine in Arabidopsis thaliana

Animal manure or bio-solids used as fertilizers are the main routes of antibiotic exposure in the agricultural land, which can have immense detrimental effects on plants. Sulfadiazine (SDZ), belonging to the class of sulfonamides, is one of the most detected antibiotics in the agricultural soil. In this study, the effect of SDZ on the growth, changes in antioxidant metabolite content and enzyme activities related to oxidative stress were analysed. Moreover, the proteome alterations in Arabidopsis thaliana roots in response to SDZ was examined by means of a combined iTRAQ-LC-MS/MS quantitative proteomics approach. A dose-dependent decrease in leaf biomass and root length was evidenced in response to SDZ. Increased malondialdehyde content at higher concentration (2 μM) of SDZ indicated increased lipid peroxidation and suggest the induction of oxidative stress. Glutathione levels were significantly higher compared to control, whereas there was no increase in ascorbate content or the enzyme activities of glutathione metabolism, even at higher concentrations. In total, 48 differentially abundant proteins related to stress/stimuli response followed by transcription and translation, metabolism, transport and other functions were identified. Several proteins related to oxidative, dehydration, salinity and heavy metal stresses were represented. Upregulation of peroxidases was validated with total peroxidase activity. Pathway analysis provided an indication of increased phenylpropanoid biosynthesis. Probable molecular mechanisms altered in response to SDZ are highlighted.

Negative bottom-up effects of sulfadiazine, but not penicillin and tetracycline, in soil substitute on plants and higher trophic levels

Veterinary antibiotics are widely used in livestock production and can be released to the environment via manure, affecting non-target organisms. Recent studies provide evidence that antibiotics can adversely affect both plants and insects but whether antibiotics in soil also affect trophic interactions is unknown. We tested whether antibiotics grown in sand as soil substitute with environmentally relevant concentrations of penicillin, sulfadiazine and tetracycline affect the survival of aphids feeding on plants (two crop and one non-crop plant species). Apera spica-venti, Brassica napus, and Triticum aestivum individuals were infested with aphids that were monitored over four weeks. We did not observe effects of penicillin or tetracycline on plants or aphids. However, sulfadiazine treatments reduced plant growth and increased mortality in the two tested grass species, but not in B. napus. Sulfadiazine subsequently decreased aphid density indirectly through reduced host plant biomass. We thus show that an antibiotic at realistic concentrations in a soil substitute can affect several trophic levels, i.e. plants and herbivores. This study contributes to the environmental risk assessment of veterinary antibiotics as it implies that their use potentially affects plant-insect interactions at environmentally relevant concentrations.

Bioconcentration and ecotoxicity of sulfadiazine in the aquatic midge Chironomus riparius

Although sulfadiazine (SDZ) is widespread in aquatic environments, information regarding the effects of SDZ on aquatic insects is still limited. In the present study, the bioconcentration and the effects of SDZ on the antioxidant system and the expression of endocrine and stress-related genes in Chironomus riparius larvae were investigated. The larvae were exposed to SDZ at the nominal concentrations of 2, 20 and 200 μg/L for 48 h. The results showed that SDZ was taken up by C. riparius despite presenting low bioconcentration factor values (0.99-3.92). In addition, superoxide dismutase activity was markedly reduced compared with the control group, whereas the levels of malondialdehyde were not significantly affected by SDZ. Moreover, the mRNA expression of genes related to heat shock proteins (Hsp70 and Hsp27) and ecdysone pathway (EcR and E74) were significantly up-regulated following all SDZ treatments. In aggregate, our work provides novel and interesting results regarding the potential biochemical and genetic effects of SDZ on freshwater insects.

Effects of biogas residues containing antibiotics on soil enzyme activity and lettuce growth

To investigate the effects of biogas residues containing antibiotics on lettuce growth and soil enzyme activity, the antibiotics oxytetracycline and sulfadiazine were used as additives; two kinds of feedstocks including pig manure and straw were chosen. Results showed that the higher the concentrations of the antibiotics are, the stronger the inhibition of soil sucrase activity becomes. The activity of sucrose enzyme in the test group with a single concentration of 60 mg/kg was significantly lower than the group that was treated with 0 mg/kg. In the mass, the organic fertilizer containing antibiotics can improve the soil urease activity and increase the urease activity of the soil. In the growth phase, urease activity increased by 27% from 0.85 mg NH3-N/(g day) in the blank group to 1.08 NH3-N/(g day) in the 0-mg test group. During all growing stages of lettuce, though the effects of the biogas residues containing oxytetracycline and sulfadiazine on the soil catalase activity were not obvious, the field application could inhibit the activity of soil catalase to some extent.

Co-exposure of Freshwater Microalgae to Tetrabromobisphenol A and Sulfadiazine: Oxidative Stress Biomarker Responses and Joint Toxicity Prediction

Combined toxicity and oxidative stress biomarker responses were determined for tetrabromobisphenol A (TBBPA) and sulfadiazine (SDZ) to the unicellular green alga Scenedesmus obliquus. Concentration-response analyses were performed for single toxicants and for mixtures containing TBBPA and SDZ with two different mixture ratios. The effect concentrations and the observed effects of the mixtures were compared to the predictions of the joint toxicity by the concentration addition (CA) model and independent action (IA) model. Results showed that the observed joint toxicity was within the scope of the highest (TBBPA) and lowest (SDZ) toxicity observed for the individual components. Furthermore, co-exposure of S. obliquus to TBBPA and SDZ provided preliminary evidence that the mixtures induced oxidative stress leading to cell damage. The CA and IA models proved to be valid for the prediction of the joint toxicity of TBBPA and SDZ. This study highlights a combined environmental risk assessment for two emerging pollutants.

Bioaccumulation of sulfadiazine and subsequent enzymatic activities in Chinese mitten crab (Eriocheir sinensis)

The bioaccumulation of sulfadiazine and subsequent enzymatic activities in Chinese mitten crab (Eriocheir sinensis) were studied in microcosms, by exposing to 50, 100, 500 and 1000ng/L of sulfadiazine for 44days. An effective method for extracting sulfadiazine in crab tissues was established by modifying the cleanup method after ultrasound extraction, with improved recoveries of 61.8%, 93.7% and 100.5% in gill, muscle and liver samples. The results showed that sulfadiazine residues were all <3ng/g dry weight in different tissues, and that sulfadiazine bioaccumulation in crab was not dose-dependent. A significantly negative correlation was observed between acetylcholinesterase activity and the residue concentration of sulfadiazine during exposure to 50ng/L and 1000ng/L, and between alkaline phosphatase and sulfadiazine residues in the 100ng/L exposure group in the gill, suggesting that the two enzymes played an important role in the metabolism of sulfadiazine in crab.

Toxicity of sulfadiazine and copper and their interaction to wheat (Triticum aestivum L.) seedlings

A pot experiment was carried out to investigate the single and combined effect of different concentrations of sulfadiazine (SDZ) (1 and 10mgkg^-1) and copper (Cu) (20 and 200mgkg^-1) stresses on growth, hydrogen peroxide (H₂O₂), malondialdehyde (MDA), antioxidant enzyme activities of wheat seedlings and their accumulation. High SDZ or Cu level significantly inhibited the growth of wheat seedlings, but the emergence rate was only inhibited by high SDZ level. The presence of Cu reduced the accumulation of SDZ, whereas the effect of SDZ on the accumulation of Cu depended on their concentrations. Low Cu level significantly increased the chlorophyll content, while high Cu level or both SDZ concentrations resulted in a significant decrease in the chlorophyll content as compared to the control. Additionally, H₂O₂ and MDA contents increased with the elevated SDZ or Cu level. The activities of superoxide dismutase, peroxidase and catalase were also stimulated by SDZ or Cu except for the aerial part treated by low Cu level and root treated by high SDZ level. The joint toxicity data showed that the toxicity of SDZ to wheat seedlings was generally alleviated by the presence of Cu, whereas the combined toxicity of SDZ and Cu was larger than equivalent Cu alone.

Reaction of antibiotic sulfadiazine with manganese dioxide in aqueous phase: Kinetics, pathways and toxicity assessment

Sulfonamide antibiotics are often detected in terrestrial and aquatic environment, but little is known about abiotic degradation of these antibiotics. In the present study, the degradation of the sulfonamide antibiotic sulfadiazine by a synthesized δ-MnO₂ was investigated. The initial reaction rate of sulfadiazine oxidized by manganese dioxide increased as the solution pH decreased by weakening electrostatic attraction between sulfadiazine and MnO₂ and enhancing the reduction potential of MnO₂. The presence of metal ions (Mn²⁺, Na⁺ and Ca²⁺), especially Mn²⁺, decreased the initial reaction rate by competitively adsorbing and reacting with MnO₂. Two different products were identified during the reaction of sulfadiazine with MnO₂ and the transformation of parent compound started with the formation of sulfadiazine radicals. Furthermore, toxicity assay results showed that the toxicity of products produced by bacteria decreased with elapse of reaction time. Results from the present study indicate that manganese dioxides in environmental matrix could be helpful in dissipation of sulfadiazine released into the environment.

Interspecific differences in growth response and tolerance to the antibiotic sulfadiazine in ten clonal wetland plants in South China

Pollution caused by residual antibiotics is a worldwide environmental issue. Antibiotic residues often occur in aquatic ecosystems, posing threats to the health of aquatic organisms. The effects of antibiotic residues on the growth of crop plants and on human health are reasonably well known. However, less is known about antibiotic effects on wetland plants. Therefore, we studied the response and tolerance of ten clonal wetland plants grown in soil spiked with sulfadiazine at 10 mg kg(-1) (an environmentally relevant concentration) and 100 mg kg(-1). At 10 mg kg(-1), ramet number was the least affected trait, while root number was the most affected among plant species. Plant shoot and total biomass were reduced in all species except in Cyperus malaccensis var. brevifolius and Panicum repens. Chlorophyll content was reduced in Alocasia macrorrhiza, Saururus chinensis, and Commelina diffusa. In general, Panicum paludosum and C. malaccensis var. brevifolius showed the least reduction of growth parameters, whereas growth of both A. macrorrhiza and S. chinensis was severely reduced. At 100 mg kg(-1), negative responses occurred in all species. Comprehensive tolerance analysis revealed that P. paludosum and C. malaccensis var. brevifolius were the species most resistant to sulfadiazine. These species are potential candidates for sulfadiazine polluted wetland restoration. A. macrorrhiza and S. chinensis were the most susceptible species and they should be protected from sulfadiazine pollution. Relative plant shoot biomass and height were the most useful indicators for evaluating plant tolerance to sulfadiazine. Plant tolerance to sulfadiazine was associated with the differences of plants in height and shoot biomass.

Acute Toxicity and Environmental Risks of Five Veterinary Pharmaceuticals for Aquatic Macroinvertebrates

Due to the high use of antibiotics and antiparasitics for the treatment of livestock, there is concern about the potential impacts of the release of these compounds into freshwater ecosystems. In this context, the present study quantified the acute toxicity of two antibiotics (sulfadiazine and sulfadimidine), and three antiparasitic agents (flubendazole, fenbendazole, ivermectin) for nine freshwater invertebrate species. These experiments revealed a low degree of toxicity for the sulfonamide antibiotics, with limited implications in the survival of all test species at the highest test concentrations (50 and 100 mg/L). In contrast, all three antiparasitic agents indicated on the basis of their acute toxicity risks for the aquatic environment. Moreover, chronic toxicity data from the literature for antiparasitics, including effects on reproduction in daphnids, support the concern about the integrity of aquatic ecosystems posed by releases of these compounds. Thus, these pharmaceuticals warrant further careful consideration by environmental risk managers.

Integrated biomarker responses in zebrafish exposed to sulfonamides

Dispersed pharmaceuticals such as sulfonamides pose a threat to aquatic ecosystems. We evaluated potential biomarkers of sulfonamide exposure using an extended zebrafish (Danio rerio) toxicity test. The tested sulfonamides induced obvious effects on spontaneous swimming activity and heartbeat rate in zebrafish. Glutathione S-transferase (GST) and malondialdehyde (MDA) were examined to reflect the biomarker response of zebrafish exposed to three sulfonamides (sulfamethoxazole, sulfadiazine (SDZ) and sulfadimidine). Both GST and MDA showed time-dependent responses to sulfonamide exposure. GST activity was significantly increased after exposure to sulfonamides for 3 days, while MDA concentration reached a maximum during the first day and then declined. These results suggest that MDA may be a more sensitive biomarker of sulfonamide toxicity than GST. These investigations demonstrated that SDZ was a typical inducer of metabolic enzymes, suggesting that it poses a potential ecotoxicological risk to aquatic ecosystems.

Chemical oxidation of sulfadiazine by the Fenton process: kinetics, pathways, toxicity evaluation

This paper investigated sulfadiazine oxidation by the Fenton process under various reaction conditions. The reaction conditions tested in the experiments included the initial pH value of reaction solutions, and the dosages of ferrous ions and hydrogen peroxide. Under the reaction conditions with pH 3, 0.25 mM of ferrous ion and 2 mM of hydrogen peroxide, a removal efficiency of nearly 100% was achieved for sulfadiazine. A series of intermediate products including 4-OH-sulfadiazine/or 5-OH-sulfadiazine, 2-aminopyrimidine, sulfanilamide, formic acid, and oxalic acid were identified. Based on these products, the possible oxidation pathway of sulfadiazine by Fenton's reagent was proposed. The toxicity evaluation of reaction solutions showed increased antimicrobial effects following the Fenton oxidation process. The results from this study suggest that the Fenton oxidation process could remove sulfadiazine, but also increase solution toxicity due to the presence of more toxic products.

Effect of pH on the toxicity and bioconcentration of sulfadiazine on Daphnia magna

The antimicrobial sulfonamide sulfadiazine has in the last decades been detected in environmental water bodies, both surface and ground water. Since pH in the environment may vary considerably, this study examined the toxicity of the amphoter sulfadiazine towards Daphnia magna at pH levels of 6.0, 7.5 and 8.5, thus taking the impact of speciation into consideration, contrary to earlier eco-toxicity studies conducted at standard conditions. Toxicity tests were performed using the standard ISO 6341 test procedure modified to accommodate the three pH levels and the toxicity was expressed as EC50. After 48 h the EC50 was determined to be 27.2, 188 and 310 mg L(-1) at pH 6.0, 7.5 and 8.5, respectively, thus demonstrating a significant effect of pH on the toxicity of sulfadiazine. Furthermore, the bioconcentration factor (dry weight) was determined to be 50 and 36 at pH 6.0 and 8.5, respectively. The higher toxicity at the lower pHs was assumed to be caused by the higher fraction of un-ionized sulfadiazine at the lower pHs. However, the one and a half fold higher bioconcentration at pH 6.0 relative to pH 8.5 does not match the more than ten times higher toxicity at pH 6.0. When comparing the fraction of neutral compound to toxicity and bioconcentration results neither toxicity nor bioconcentration can be ascribed solely to the unionized fraction of sulfadiazine.

Severe hepatotoxicity and probable hepatorenal syndrome associated with sulfadiazine

PURPOSE. The case of a patient who developed hepatorenal syndrome during treatment with sulfadiazine for toxoplasmosis retinitis is reported.

SUMMARY

A 20-year-old Caucasian woman weighing 59 kg was admitted to the infectious diseases ward of a hospital in May 2009 with nausea, vomiting, and jaundice. In March 2009, she was diagnosed with toxoplasmosis retinitis and received sulfadiazine 3 g daily, pyrimethamine 50 mg daily, leucovorin 15 mg daily, and prednisolone 75 mg daily; she continued these medications for three weeks. After the development of gastrointestinal symptoms, she stopped taking the prescribed medications (five days before hospital admission). One day before hospital admission, her skin appeared jaundiced. At the time of admission, the patient had high transaminase levels, hyperbilirubinemia, abnormal prothrombin time and International Normalized Ratio values, and clinical evidence of acute fulminant hepatitis complicated by hepatorenal syndrome. Autoimmune hepatitis was excluded as a cause of her hepatotoxicity, as was Wilson's disease, herpes simplex virus, cytomegalovirus, hepatitis A virus, hepatitis E virus, and Epstein-Barr virus. She was diagnosed with probable drug-related fulminant hepatitis, presumably caused by sulfadiazine treatment. Lactulose 20 g was started for the prevention of encephalopathy. She received phytonadione 10 mg daily for three consecutive days, ranitidine 50 mg thrice daily, ciprofloxacin 250 mg twice daily, and acetylcysteine 600 mg thrice daily. The patient underwent hemodialysis five times during her hospital stay. Her symptoms gradually improved, and she was discharged on hospital day 20.

CONCLUSION

Probable hepatorenal syndrome requiring hemodialysis occurred in a patient receiving sulfadiazine for the treatment of toxoplasmosis retinitis.

Eco-toxic effects of sulfadiazine sodium, sulfamonomethoxine sodium and enrofloxacin on wheat, Chinese cabbage and tomato

Investigation of the toxic effects of three veterinary drugs [sulfadiazine sodium (SDS), sulfamonomethoxine sodium (SMMS), and enrofloxacin (EFLX)] on seed germination, root elongation and shoot elongation of wheat (Triticum aestivum L.), Chinese cabbage (Brassica campestris L.) and tomato (Cyphomandra betacea) was carried out. Significant linear relationships between the root and shoot elongation and the concentration of veterinary drugs addition were observed. The effects of the three veterinary drugs on seed germination of wheat, Chinese cabbages and tomato were not significant (P > 0.05), but on shoot and root elongation they were markedly significant (P < 0.05). The inhibitory rates of veterinary drugs on root and shoot elongation of crops were significantly stronger than that on seed germination. Based on IC(50) (drugs concentration when 50% plants show inhibition) of root elongation, wheat was the most sensitive plant to the toxicity of SDS with a IC(50) value as high as 28.1 mg/kg; Chinese cabbage was the most sensitive plant to the toxicity of SMMS with a IC(50) value as high as 27.1 mg/kg; tomato was the most sensitive plant to the toxicity of EFLX with a IC(50) value as high as 125.7 mg/kg. The toxic effects of sulfadiazine sodium and sulfamonometh-oxine sodium on the three crops were much higher than that of enrofloxacin.

Alterations in soil microbial activity and N-transformation processes due to sulfadiazine loads in pig-manure

Most veterinary drugs enter the environment via manure application. However, it is unclear how these substances interact with soil biota. Therefore, it was the aim of the present study to investigate the effects of manure containing different concentrations of the antibiotic sulfadiazine (SDZ) on the soil microbial communities. It was shown that manure alone has a stimulating effect on microbial activity. Only potential nitrification was negatively influenced by manure application. The addition of SDZ to the manure reduced microbial activity. Depending on the SDZ concentration, levels of activity were in the range of the control soil without manure application. Also, selected processes in nitrogen turnover were negatively influenced by the addition of SDZ to the manure, with nitrification being the only exception. The effects were visible for up to 4 days after application of the manure with or without SDZ and were correlated with the bioavailability of the antibiotic.

Antibiotic Sensitivity Patterns among Indian Strains of Avian Pasteurella multocida

An investigation was carried out to study the antibiotic sensitivity of avian strains of Pasteurella multocida and to select an effective antimicrobial agent for control of avian pasteurellosis in India. A total of 123 strains of P. multocida recently isolated from different avian species (chicken, duck, turkey, quail, and goose), from different regions of India were subjected to antibiotic sensitivity tests using 20 different antibiotics. Absolute resistance was observed against sulfadiazine. The studies indicated that the strains were most sensitive to chloramphenicol (73.98%), followed by enrofloxacin (71.54%), lincomycin (64.23%), norfloxacin (61.79%) and doxycycline-HCl (56.91%). The majority of the strains were found to exhibit intermediate sensitivity. Chloramphenicol was selected and suggested for treatment. Antibiogram studies also revealed the emergence of multidrug-resistant strains of P. multocida among Indian poultry.

Interaction between lead toxicity and some sulphonamides in rabbits: effect on certain blood constituents and serum enzymes

Two main equal groups of clinically healthy, non pregnant rabbits were classified into 4 subgroups (5 rabbits each). The 1st and 2nd subgroups were treated with sulphaquinoxaline or sulphadiazine in a single oral dose of 100 mg/kg b. wt., while the 3rd and 4th subgroups received a repeated oral dose of 100 mg/kg b. wt., daily for 5 successive days, respectively. The second main group received lead acetate in a dose of 4.2 mg/kg b. wt. per day for 2 months, then was classified as in case of the 1st main group and administered the respective sulphonamides in their recommended doses. The experimental lead intoxication was found to decrease the free delta-aminolevulinic acid dehydratase (delta-ALA-D) activity in blood of lead intoxicated rabbits after 4 and 8 weeks. Also, the ratio of free and with glutathione reactivated delta-ALA-D was increased 2.9 and 2.2 after 4 and 8 weeks, respectively as compared with before lead administration (1.19), indicating toxicity. The sulphonamide/creatinine ratio was increased after administration of both sulphonamides but higher in lead intoxicated rabbits as compared with healthy ones. The AST/ALT ratio was decreased 4 and 8 weeks after lead exposure. The AST, ALT and AST/ALT ratio, alkaline phosphatase, urea and creatinine were not altered in healthy rabbits. Repeated oral administration of sulphadiazine caused a significant increase in serum AST, ALT, alkaline phosphatase and creatinine level in healthy and lead intoxicated rabbits. On the other hand, AST/ALT ratio in both healthy and lead intoxicated rabbits was found to decrease 1 h after the last dose as compared with before treatment.

In vitro evaluation of a toxic metabolite of sulfadiazine

We have demonstrated the in vitro production of a potentially toxic metabolite of sulfadiazine Human lymphocytes were incubated with sulfadiazine and a murine hepatic microsomal drug metabolizing system. Toxicity to cells was assessed by trypan blue dye exclusion. Covalent binding of labelled sulfadiazine to microsomes also was studied. Sulfadiazine toxicity to cells was dependent on microsomes and NADPH. Binding and toxicity were decreased when microsomes were boiled or cytochrome P-450 inhibited, and by the addition of N-acetylcysteine or glutathione. The data suggest the production of a toxic intermediate of oxidative metabolism of sulfadiazine which is detoxified by conjugation with glutathione. Covalent binding of such metabolites to cell macromolecules could lead to cell death and, by acting as haptens, to secondary hypersensitivity reactions.

Patch testing with silver sulfadiazine cream

23 patients who had used silver sulfadiazine cream were patch tested. No reactions to the active principle occurred but 2 vehicle components, cetyl alcohol and propylene glycol, were positive. No sulfonamide-sensitive subject reacted to silver sulfadiazine. There is no evidence that silver sulfadiazine has a contact sensitizing potential or that it is contra-indicated for patients with a history of sulfonamide hypersensitivity.

Metal sulfonamides as antibacterial agents in topical therapy

The apparent efficacy of zinc and cerium sulfadiazine and the metabolic role of other trace metals suggested that sulfonamide salts of these might be of therapeutic value. There is also a possibility that metal salts of other sulfonamides might be useful. Accordingly other sulfonamide salts of zinc were prepared and studied in vitro and in vivo. Only zinc sulfathiazole and zinc methoxazole were as effective as zinc sulfadiazine in animal studies. The sulfadiazines of aluminum, chromium, cobalt, copper and iron were prepared and compared in vitro and in vivo. Only cobalt sulfadiazine appeared comparable to zinc and cerium sulfadiazine in healing burn wounds in rats. Studies on the molecular structure of silver sulfonamides disclosed the polymeric structure peculiar to silver sulfadiazine which appears to account for its unique properties. It is not yet known whether other metal sulfadiazines have this attribute.

Zinc sulfadiazine for topical therapy of pseudomonas infection in burns

Zinc sulfadiazine is a new compound which is effective in vitro and in vivo against Pseudomonas aeruginosa infections in burned mice and rats. It contains an important body constituent, zinc, and appears to expedite wound healing, diminish weight loss after infected burns and improve food intake. Like silver sulfadiazine, it prevents the postburn changes in plasma proteins. After topical application, the uptake of the radioactively labeled zinc is significant in the zone of injury and negligible in organs and body fluids. The binding to deoxyribonucleic acid by zinc is similar to, but less than, that by silver. The data indicate that zinc sulfadiazine may be a valuable addition to the therapeutic armamentarium for the control of burn wound sepsis.

Studies in dogs and cats dosed with trimethoprim and sulphadiazine

Serum level studies in cats and dogs dosed with 30 mg per kg per day of either oral or injectable formulations of a 1:5 trimethoprim/sulphadiazine combination showed good absorption by both routes of administration. Toxicity tests with the products demonstrated a high margin of safety in dogs given this dose level; the margin of safety in cats was lower but still adequate. The high success rate in clinical trials against a wide range of bacterial infections confirmed the predictions from the serum level results that a dose rate of 30 mg per kg per day orally or parentally, would be therapeutically efficacious in both species.

In vitro activity of silver sulfadiazine against Herpesvirus hominis

Silver sulfadiazine, at a concentration of 10 mug/ml, inhibits Herpesvirus hominis types 1 and 2 in vitro. The antiviral effect is directly related to concentration of the drug and duration of exposure.

Orally-administered silver sulfadiazine: chemotherapy and toxicology in CF-1 mice; Plasmodium berghei (Malaria) and Pseudomonas aeruginosa

Silver sulfadiazine when administered orally and subcutaneously to CF-1 mice in doses not exceeding 1,050 mg/kg proved to have minimal toxicity. No pathology or abnormal reactions were seen in CF-1 mice after receiving 1,050 mg/kg orally and subcutaneously once a day for 30 days. Silver sulfadiazine in doses of 1,050 mg/kg, once a day for 5 days cured mice of Plasmodium berghei even after splenectomy. Parasitemia was reduced to zero in 1-3 days and antimalarial activity was not inhibited significantly with doses of 313 mg/kg/day of PABA, thereby indicating that silver sulfadiazine's antimalarial mode of action is different from that of the sulfonamides. Doses of 1,050 mg/kg/day had significant activity against systemic infections of Pseudomonas aeruginosa.