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PubMed2006

Effect of low-level helium-neon laser therapy on the healing of third-degree burns in rats.

This paper presents the results of a study on the effects of low-level helium-neon laser therapy (LL He-Ne LT) on the healing of burns. Seventy-eight adult male rats, having been subjected to third-degree burns, were randomly divided into four groups: two laser treated groups (n=20, each), one control group (n=19) and one nitrofurazone treated group (n=19). In the two laser treated groups, the burns were treated on a daily basis with LL He-Ne LT with an energy density of 1.2 and 2.4 J/cm(2), respectively. The response to treatment was assessed histologically at 7, 16 and 30 days after burning, and microbiologically at day 15. Analysis of variance showed that the mean of blood vessel sections in the 1.2J/cm(2) laser group was significantly higher than those in the other groups and the mean of the depth of new epidermis in the 2.4 J/cm(2) laser group on day 16 was significantly lower than in the nitrofurazone treated group (P=0.025, P=0.047, respectively). When Staphylococcus aureus and Pseudomonas aeruginosa grew in more than 50% of samples obtained from control group, there were no S. aureus and P. aeruginosa in the samples of 2.4 J/cm(2) laser group. It is concluded that LL He-Ne LT induced the destruction of S. aureus and P. aeruginosa in third-degree burns of rats, yet at the same time our histological findings showed that LL He-Ne LT caused a significant increase in the mean of blood vessel sections on day 7 after third degree burns and a decrease in the mean of the depth of new epidermis on day 16 after the same burns in rats.

Animals↗
PubMed2000

Xenobiotic-mediated production of superoxide by primary cultures of rat cerebral endothelial cells, astrocytes, and neurones.

Previous works of our group demonstrated that xenobiotic metabolism by brain microsomes or cultured cerebral cells may promote the formation of reactive oxygen species. In order to characterise the risk of oxidative stress to both the central nervous system and the blood-brain barrier, we measured in the present work the release of superoxide in the culture medium of rat cerebrovascular endothelial cells during the metabolism of menadione, anthraquinone, diquat or nitrofurazone. Assays were run in the same experimental conditions on primary cultures of rat neurones and astrocytes. Quinone metabolism efficiently produced superoxide, but the production of radicals during the metabolism of diquat or nitrofurazone was very low, as a probable result of their reduced transport inside the cells. In all cell types assayed, superoxide production was time- and concentration-dependent, and cultured astrocytes always produced the highest amounts of radicals. Superoxide formation by microsomes prepared from the cultured cells was decreased by immunoinhibition of NADPH-cytochrome P450 reductase or by its irreversible inhibition by diphenyliodonium chloride, suggesting the involvement of this flavoprotein in radical production. Cerebrovascular endothelial cells cultured on collagen-coated filters produced equivalent amounts of superoxide both at their luminal side and through the artificial basement membrane, suggesting that in vivo, endothelial superoxide production may endanger adjacent astrocytes and neurones.

Animals↗
PubMed2005

Transfer of nitrofuran residues from parent broiler breeder chickens to broiler progeny.

The use of nitrofuran antibiotics in food-producing animals is prohibited within the EU. Countries in the EU, as well those intending to export food to the EU, must ensure that their products are free from nitrofuran residues. As a result of recent global problems where chicken meat from a wide range of countries has been contaminated with nitrofuran metabolites, an investigation was performed to discover whether or not residues of the nitrofurans might be transferred from parent breeder chickens to their offspring broilers. Four groups of broiler breeders were each treated with one of the nitrofurans: furazolidone, nitrofurazone, nitrofurantoin or furaltadone. Residues of their side-chain metabolites, AOZ, SEM, AHD and AMOZ, were detected in the fertilised eggs at concentrations up to 1567 microg/kg. However, in the chicks that subsequently hatched from these eggs, residue concentrations of SEM, for example, were only found up to 26.6 and 32.5 microg/kg in liver and muscle, respectively, for 1-d-old chicks. Residue concentrations in tissues had fallen below the detection limit of the analytical method for 40-d-old broiler chicks, for all compounds except for semicarbazide (SEM, the nitrofurazone metabolite). Relatively high concentrations of nitrofurans are available to the newly hatched chick through the egg yolk. However, most of these residues are neither utilised nor deposited in the liver or muscle.

Aging↗
PubMedDate not supplied

Cytotoxicity testing of topical antimicrobial agents on human keratinocytes and fibroblasts for cultured skin grafts.

Cultured epidermal skin has become an adjunctive therapy for treatment of major burn injuries, but its effectiveness is greatly limited because of destruction by microbial contamination. To evaluate candidate antimicrobial agents for use with cultured skin, a combined cytotoxicity-antimicrobial assay system was developed for determination of toxicity to cultured human keratinocytes and fibroblasts and for determination of susceptibility or resistance of common burn wound organisms. Candidate agents including chlorhexidine gluconate, polymyxin B, mupirocin, sparfloxacin, or nitrofurazone were tested separately for inhibition of growth of human cells and for inhibitory activity to microorganisms with the wet disk assay. The data showed that (1) chlorhexidine gluconate (0.05%) was uniformly toxic to both cultured human cells and microorganisms; (2) nitrofurazone (0.02%) had dose-dependent toxicity to human cells and limited effectiveness against gram-negative microorganisms; (3) sparfloxacin (30 micrograms/ml) had low toxicity to human cells and retained antimicrobial activity against both gram-positive and gram-negative bacteria; (4) polymyxin B (400 U/ml) was not toxic to human cells and had intermediate effectiveness on gram-negative bacteria; and (5) mupirocin (48 micrograms/ml) had no toxicity to skin cells and had uniform effectiveness against Staphylococcus aureus including methicillin-resistant Staphylococcus aureus. Selection of topical antimicrobial drugs by these assays may improve effectiveness of cultured skin for burns and may be used to control other surgical wound infections.

Administration, Topical↗
PubMed1981

Type I nitroreductases of Escherichia coli.

Analysis of partially purified crude extract of Escherichia coli K12 by chromatography and gel electrophoresis has resulted in the separation of three distinct activities which catalyse the reduction of nitrofurazone (semicarbazone of 5-nitro-2-furaldehyde) in the presence of oxygen (type I nitroreductases). The major enzymatic activity (type IA), which was dependent solely on NADPH as a cofactor, was absent from nitrofurazone-resistant strains NFR 402 and NFR 502, but present in SIL 41, a strain which is only marginally resistant to the nitrofuran. The remaining nitroreductase activities (IB1 and IB2) utilize either NADH or NADPH as a cofactor. These activities coelute from DEAE-cellulose at pH 7.2, but may be differentiated by their behaviour on CM-cellulose at pH 5.8. The reductase activity missing in SIL 41 was observed in extracts of strain NFR 402 but not NFR 502. This enzyme (IB1) though retained by DEAE-cellulose had no affinity for CM-cellulose. The only reductase present in extracts of NFR 502 (a nitrofuran-resistant strain selected after two mutational events) was type IB2. This activity, also detectable in SIL 41 and NFR 402, has not been mapped genetically. An interesting feature of the type IB2 enzyme is its apparent inactivation by MnCl2 which has been routinely used as a partial purification step in the past.

Cell-Free System↗
PubMedDate not supplied

[Antimicrobial drugs in poultry nutrition: resistance levels in Escherichia coli].

In a battery experiment, a hundred of day old broiler chicks (Hubbard) divided into ten groups, were fed for eight weeks with 50, 75 or 100mg/Kg of ration of chloramphenicol and tetraciclyne; 40, 80 or 120mg/ 2 liters of drinking water of nitrofurazone. During three months defecated feces from each bird were sampled and analysed at intervals of 15 days for the isolation of Escherichia coli strains which were submitted to the determination of drug resistance. The results showed that utilization of antimicrobial drugs selected a resistant population of Escherichia coli at 300 microgram/ml of chloramphenicol tetraciclyne and 30 microgram/ml of nitrofurazone, during the dietary period. In addition the characterization of the R factor made by conjugation against apropriated recepient strains, demonstrated it's presence in some of the tested strains has only been noted the mobilization of the tetraciclyne marker.

Animal Feed↗
PubMed1976

Outpatient burns: a prospective study.

1) There is no significant difference in overall wound healing rates between non-antibacterial and antibacterial impregnated dressings used in this study. 2) The burn wound is not sterile. 3) Ease of dressing removal was similar during the first 7 days; thereafter the nitrofurazone dressings were more adherent; however, patient acceptance as subjectively evaluated at the time of dressing change and from the description of intervals between dressing changes did not vary significantly between the two dressings. 4) Pathogenic flora, both gram-positive and gram-negative, were significantly less prevalent in wounds treated with nitrofurazone dressings when the closed technique for burn treatment was utilized.

Adolescent↗
PubMed1994

Mutagenicity testing in Salmonella typhimurium strains possessing both the His reversion and Ara forward mutation systems and different levels of classical nitroreductase or O-acetyltransferase activities.

The induction of forward mutations to L-arabinose resistance (AraR) and of reversions to histidine prototrophy (His+) can be quantitatively compared in Salmonella typhimurium BA strains. The BA bacteria carry the araD531 allele required for the Ara assay and a his auxotrophy (hisD3052 or hisG46) required for the His assay. In this study, 2 new sets of BA indicator strains have been constructed in order to combine the Ara forward and the His reverse mutation assays of S. typhimurium with deficiency, or over-production, in either classical nitroreductase or O-acetyltransferase for mutagenicity testing of nitro-containing chemicals. Nine mutagens with different chemical structures were tested to compare the specific mutagenic sensitivities of the new constructions with those of the parental and of the conventional TA indicator bacteria. The Ara test, which responded with high sensitivity to all chemicals tested, revealed important differences between the standard tester strains TA98 and TA100 with respect to the activation of mutagens considered to be dependent on classical nitroreductase activity. Total correspondence was found between the specific mutagenic sensitivities of the defective and the overproducing bacteria in the genetic background of TA98 but not in that of TA100. In the genetic background of TA100, chemicals such as nitrofurantoin and nitrofurazone displayed 10-fold reduced mutagenicity to the "classical nitroreductase" defective strain without increasing mutagenicity to the corresponding overproducing bacteria. This discrepancy might be attributed to the greater nitroreduction capability of strain TA100 (68.12 nmole/min/mg protein) as compared to TA98 (24.42 nmole/min/mg protein), by assuming that nitrofurantoin and nitrofurazone are such good substrates for classical nitroreductase that the additional enzyme activity produced from the corresponding overexpressing plasmid when present in TA100 no longer affected their metabolic activation. We propose that the Ara forward mutation test carried out in the set of over-producing bacteria constructed in the genetic background of TA98 might play a role for routine testing of large number of samples. The isogenic defective strains could be used in cases of uncertain results with the corresponding over-producing bacteria. Finally, the reversion of the his alleles accompanying the Ara assay in the BA strains could play a role in assessing the presence of mixtures of chemicals with different mutagenic specificity in samples of environmental relevance such as urban air, foods, and water.

Arabinose↗
PubMed1984

Nitroheterocycle metabolism in mammalian cells. Stimulation of the hexose monophosphate shunt.

Misonidazole, SR-2508, nitrofurazone and other nitroheterocycles stimulated release of 14CO2 from [1-14C]glucose but not from [6-14C]glucose when incubated with mouse Ehrlich ascites cells or human A549 lung carcinoma cells in vitro. This demonstrated that the nitro compounds activated the hexose monophosphate shunt and is evidence that an important pathway of nitro reduction in these cell lines is electron transfer from NADPH-dependent cytochrome c reductase to the nitro group. Shunt activity was stimulated under both aerobic and anaerobic conditions. For catalase-free Ehrlich cells, aerobic effects were greater than anaerobic, indicating that NADPH was used for reduction of H2O2, via GSH peroxidase and reductase, as well as for one-electron nitro reduction, under aerobic conditions. Several of the compounds tested stimulated 14CO2 release from [2-14C]glucose as well as from [1-14C]-glucose. This shows that the cellular requirement for NADPH, in the presence of nitro drug, was great enough to cause recycling of pentose phosphates. Recycling could decrease the availability of ribose-5-P needed for nucleic acid synthesis, which could partly explain the inhibition of DNA synthesis observed upon prolonged aerobic incubation of cells with nitro compounds. Comparison of the rate of disappearance of nitrofurazone from anaerobic A549 cell suspensions with the rate of 14CO2 release suggests that the drug reduction in this cell line was catalyzed almost entirely by NADPH-requiring enzymes.

Anaerobiosis↗
PubMed1991

Inhibition of T cell mitogenesis by nitrofurans.

A group of nitrofurans (5-nitro-2-furaldehyde, nifuroxime, nitrofurazone, nitrofurantoin, 5-nitro-2-furoic acid and 2-nitrofuran) were evaluated for inhibition of mitogenesis (DNA synthesis) in human peripheral blood T cells. T cells, either triggered by phorbol myristate acetate (PMA) or in the presence of accessory cells, were activated with a specified mitogen [phytohemagglutin (PHA), concanavalin A (ConA), or anti-CD3] and the amount of tritiated thymidine incorporated into DNA was determined. The results obtained indicate that nitrofurans inhibit mitogenesis irrespective of activator. 5-Nitro-2-furaldehyde was much more inhibitory than the other compounds, while 2-nitrofuran was less inhibitory. When the aldehyde group (5-nitro-2-furaldehyde) was replaced by a carboxyl group (5-nitro-2-furoic acid), the inhibitory activity was also reduced greatly. These results show that while the nitro group alone confers inhibitory activity to the furan ring, the group at the 2 position is crucial. In general, the mitogenic response of purified T cells (lacking accessory cells) triggered by PMA (phorbol ester) was inhibited less than that of the T cell-accessory cell system. With the latter, 50% inhibition of T cell mitogenesis was achieved by nifuroxime, nitrofurazone, and nitrofurantoin at 45-51 and 34-39 microM with PHA and ConA respectively. When purified T cells were used, the values were 71-85 and 55-60 microM respectively. For a given drug concentration, mitogenesis was more inhibited when induced by ConA or anti-CD3 than by PHA. The importance of using a single cell system (purified T cells) was emphasized by the interesting finding that only this system showed enhancement of mitogenesis, up to 35-40% at low drug levels. With the exception of the nitrofuraldehyde, the nitrofurans at strongly inhibitory levels were only moderately cytotoxic, exhibiting 62-85% cell survival after exposure to drug for 68 hr. Our results suggest that nitrofurans inhibit T cell mitogenesis by a relatively non-toxic mechanism; these results are comparable to those obtained for mammalian cells under aerobic conditions.

Adult↗
PubMed1992

Evaluation of the penetration strength, bactericidal efficacy and spectrum of action of several antimicrobial creams against isolated microorganisms in a burn centre.

The antibacterial activity of eight antiseptic creams: 1 per cent silver sulphadiazine; 0.2 per cent nitrofurazone; 0.1, 0.5 and 1 per cent chlorhexidine; 2.2 per cent cerium nitrate; 10 per cent povidone iodine; and 1 per cent silver sulphadiazine with 2.2 per cent cerium nitrate were evaluated in vitro. The evaluation included the minimum inhibitory concentration (MIC) against 100 microorganisms isolated from burn patients, the chronology of the bacterial activity against Ps. aeruginosa and Staph. aureus and the penetration strength of the creams through a novel in vitro model contaminated with 17 microorganisms of different species isolated from burn patients. The results revealed that 0.5 per cent or 1 per cent chlorhexidine, 2.2 per cent cerium nitrate, and 1 per cent silver sulphadiazine with 2.2 per cent cerium nitrate were the creams which were effective at the highest dilutions. 0.5 per cent chlorhexidine and 10 per cent povidone iodine had the greater bactericidal activity. Finally, 0.2 per cent nitrofurazone showed greater penetration strength within the eschar model in comparison with the weaker penetration of 0.5 per cent and 1 per cent chlorhexidine and the absence of penetration by the rest of the antibacterial creams.

Administration, Topical↗
PubMed1998

Drug metabolizing enzyme activities and superoxide formation in primary and immortalized rat brain endothelial cells.

The activities of several enzymes involved in drug metabolism, NADPH-cytochrome P450 reductase, cytochrome P450 isoforms CYP1A and CYP2B, and uridine diphosphate glucuronosyltransferase (UGT) have been measured in primary cultures of rat cerebrovascular endothelial cells and in the immortalized rat brain endothelial cell line RBE4. These drug metabolizing activities were similar in the microsomes prepared from both cell types, even after 20 passages for RBE4 cells. These results were confirmed by Western immunoblotting analysis, using polyclonal antibodies raised against rat liver enzymes. The superoxide production observed during NADPH-cytochrome P450 reductase-dependent monoelectronic reduction of four xenobiotics, menadione, anthraquinone, nitrofurazone and diquat, was also investigated in these cultured cells at confluence. The rates of radical production were concentration-dependent. The superoxide formation induced by quinone metabolism was comparable in both cell cultures, and high amounts of superoxide radicals were produced even after 20 passages of RBE4 cells. On the other hand, nitrofurazone and diquat metabolism produced weak amounts of superoxide radicals in both cell types. Taken together, these results suggest that RBE4 cell line seems to constitute a valuable in vitro model for studies on the activity of some enzymatic systems involved in drug metabolism at the blood-brain barrier and the functional consequences of their activity.

Animals↗
PubMed1997

A new stable pluronic F68 gel carrier for antibiotics in contaminated wound treatment.

Pluronic F68 was selected as the gel carrier for antimicrobial agents because of its extensive use as a wound cleanser in humans without discernable side effects. When the concentration of this surfactant is increased to 46%, it forms a water soluble gel that can serve as a carrier for antimicrobial agents. The stability of this gel can be enhanced by immediately cooling (-15 degrees C) the gel for 24 hours before storage and subsequent application. Immediate cooling of the gel causes hydration of the surfactant that is associated with gel strengthening and prolonged shelf life stability. In experimental animals, this stable gel carrier containing 0.2% nitrofurazone significantly reduces the bacterial concentration of Staphylococcus aureus in wounds to a greater degree than silver sulfadiazine. This antimicrobial gel has the same antimicrobial activity as polyethylene glycol carriers containing 0.2% nitrofurazone, but does not carry the potential risk of polyethylene glycol intoxication.

Animals↗
PubMed2001

Induction of rat liver cytochrome P450 isoenzymes CYP 1A and CYP 2B by different fungicides, nitrofurans, and quercetin.

The genotoxic activity of environmental xenobiotics is manifested either in their direct interaction with cellular genetic material or in provoking secondary events, among which reactive oxygen species (ROS) production is a common phenomenon. Both pathways can be mediated by the activity of the cytochrome P450 monooxygenase system. We studied induction of the CYP 1A or CYP 2B monooxygenases in rat liver by the fungicides: thiram, captan, captafol, dodine and the drugs: nitrofurazone, furazolidone and the plant flavonoid: quercetin. A cytochrome P450 induction assay (CYPIA test) was used. S9 prepared from livers of rats treated with the test compounds were used to activate ethidium bromide (EtBr) (CYP 1A isoenzyme) or cyclophosphamide (CPA) (CYP 2B isoenzyme) in the Ames test. It was found that among the tested compounds, the most potent inducer of CYP 1A was furazolidone (3 x 80 mg/kg). Less potent was thiram (1 x 100mg/kg), as well as quercetin (3 x 80 mg/kg), and captafol (1 x 30 mg/kg). On the other hand, thiram (1 x 100 mg/kg), captafol (1 x 30 mg/kg), and quercetin (3 x 80 mg/kg) were most potent in the CYP 2B isoenzyme induction, while furazolidone (3 x 80 mg/kg), and nitrofurazone (3 x 80 mg/kg) appeared to be less potent in this respect. Captan and dodine (3 x 80 mg/kg) did not affect the activity of any of the cytochrome P450 isoenzymes.

Animals↗
PubMed2006

Application of a microfluidic reactor for screening cancer prodrug activation using silica-immobilized nitrobenzene nitroreductase.

The nitroreductase-catalyzed conversion of a strong electron-withdrawing nitro group to the corresponding electron-donating hydroxylamine is useful in a variety of biotechnological applications. Activation of prodrugs for cancer treatments or antibiotic therapy are the most common applications. Here, we show that a bacterial nitrobenzene nitroreductase (NbzA) from Pseudomonas pseudoalcaligenes JS45 activates the dinitrobenzamide cancer prodrug CB1954 and the proantibiotic nitrofurazone. NbzA was purified by affinity chromatography and screened for substrate specificity with respect to prodrug activation. To facilitate screening of alternate potential prodrugs, polyethyleneimine-mediated silica formation was used to immobilize NbzA with high immobilization yields and high loading capacities. Greater than 80% of the NbzA was immobilized, and enzyme activity was significantly more stable than NbzA in solution. The resulting silica-encapsulated NbzA was packed into a microfluidic microreactor that proved suitable for continuous operation using nitrobenzene, CB1954, and the proantibiotic nitrofurazone. The flow-through system provides a rapid and reproducible screening method for determining the NbzA-catalyzed activation of prodrugs and proantibiotics.

Antineoplastic Agents↗
PubMed1976

Chemistry and antibacterial activity of nitrobenzofurans.

Thirteen 2-methylbenzofurans were synthesized and their antibacterial activity was investigated. 2-Methyl-3-nitrobenzofuran and analogs containing 7-NO2, 5-NO2, 7-Br, 7-CONH2, and 7-CF3 substituents are bacteriostatic. The spectrum of activity of these compounds is similar to nitrofurazone; however, a strain of E. coli Br which has increased resistance to nitrofurazone did not show increased resistance to 3,7-dinitro-2-methylbenzofuran (1). The 3-nitro-2-methylbenzofurans are labile in solution (T1/2 0.8-3.5 hr at 37 degrees, pH 7.0). The solvolysis product of 1 was identified as alpha,6-dinitro-o-cresol (15). The 3-nitrobenzofurans are more potent in minimal media than in Penassay broth. This greater potency can be abolished by addition of casamino acids and tryptophan to the minimal media.

Anti-Bacterial Agents↗
PubMed1998

Nitroreduction of nitrated and C-9 oxidized fluorenes in vitro.

Widespread environmental pollution with mutagenic and carcinogenic nitrofluorenes contributes to human health risks. Since nitroreduction leads to activation of many nitro compounds, nitroreduction of the nitrofluorene (NF) derivatives by one- and two-electron reductants was examined. Rates of nitroreduction catalyzed by xanthine oxidase (XO)/hypoxanthine and measured via stimulation of acetylated cytochrome c reduction increased with the number of nitro groups and oxidation at C-9: 9-oxo-2,4,7-triNF > 9-oxo-2,7-diNF > 2,7-diNF > 9-oxo-2-NF = 2,5-diNF > 9-hydroxy-2-NF > 2-NF. Ascorbate catalyzed one-electron reduction to nitro anion radicals which reacted with molecular O2 to yield superoxide. Rates of O2 uptake with 9-oxo-2,4,7-triNF and 9-oxo-2,7-diNF were 63 and 0.17 times those, respectively, with equivalent concentrations of nitrofurazone, a classical substrate. Superoxide formation was indicated by the approximately 75% regeneration of O2 upon addition of superoxide dismutase and catalase. 9-Oxo-2,4,7-triNF stimulated O2 uptake in the presence of XO/NADH with typical Michaelis-Menten kinetics with an apparent Km of 0.476 +/- 0.054 microM versus a Km of 6.18 +/- 0.719 microM for nitrofurazone. HPLC analyses of products from reduction catalyzed by XO or diaphorase of Clostridium with NADH showed the following trends for the rates of amine formation from 9-oxo-2,7-diNF > 2,7-diNF; 9-oxo-2-NF > 9-hydroxy-2-NF > 2-NF; 2,7-diNF > 2-NF; and 9-oxo-2,7-diNF > 9-oxo-2-NF. Little or no amine was formed in 95% O2, suggesting O2-labile intermediates. The data herein suggest that oxidation at C-9 and multiple nitro groups increase the potential for nitroreduction of the nitrofluorenes in vivo which may lead to genotoxic effects.

Acetylation↗
PubMed2005

The occurrence of nitrofuran metabolites in the tissues of chickens exposed to very low dietary concentrations of the nitrofurans.

The global problem of food products contaminated by residues of the banned carcinogenic nitrofuran drugs has prompted research into how such residues accumulate in tissues. In the study described here, two aspects have been investigated where the nitrofurans accumulate in tissues from chickens exposed to either a dietary or an environmental source of contamination. Twenty groups of broilers were fed a diet containing one of the nitrofurans: furazolidone, nitrofurazone, nitrofurantoin or furaltadone at concentrations of 30, 100, 300, 1000 and 3000 microg kg(-1). At the lowest concentration of furazolidone contamination (0.01% of the therapeutic dose) tissue bound AOZ metabolite residues were detected in liver (1.1 +/- 0.2 microg kg(-1)) and in muscle (0.33 +/- 0.03 microg kg(-1)). Similar results were obtained for AMOZ (0.6 +/- 0.2 microg kg(-1) in liver), the tissue bound metabolite of furaltadone. There was no appreciable accumulation of nitrofurantoin in chicken muscle. The AHD metabolite was not detected in muscle from birds fed nitrofurantoin at either 30 or 100 microg kg(-1). For nitrofurazone the concentrations of the SEM metabolite were higher in muscle than in liver for all dietary concentrations. The potential for a contaminated environment to cause nitrofuran residues in chickens was investigated. Six chickens were placed in a pen that was previously occupied by birds fed a diet containing 3000 microg kg(-1) of furazolidone. After 24 hours' exposure of the chickens to the litter in the pen, AOZ residues of 0.13 +/- 0.04 and 0.10 +/- 0.03 microg kg(-1) were detected in liver and muscle, respectively. The results of both experiments have implications for the poultry industry in trying to eliminate nitrofurans from their production systems, and for regulatory analysts faced with the detection of low concentrations of the drugs, both in tissues and in feedingstuffs.

Animal Feed↗