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Sample records for activate metronidazole nitroreductases

  1. Giardia, Entamoeba, and Trichomonas enzymes activate metronidazole (nitroreductases) and inactivate metronidazole (nitroimidazole reductases).

    PubMed

    Pal, Dibyarupa; Banerjee, Sulagna; Cui, Jike; Schwartz, Aaron; Ghosh, Sudip K; Samuelson, John

    2009-02-01

    Infections with Giardia lamblia, Entamoeba histolytica, and Trichomonas vaginalis, which cause diarrhea, dysentery, and vaginitis, respectively, are each treated with metronidazole. Here we show that Giardia, Entamoeba, and Trichomonas have oxygen-insensitive nitroreductase (ntr) genes which are homologous to those genes that have nonsense mutations in metronidazole-resistant Helicobacter pylori isolates. Entamoeba and Trichomonas also have nim genes which are homologous to those genes expressed in metronidazole-resistant Bacteroides fragilis isolates. Recombinant Giardia, Entamoeba, and Trichomonas nitroreductases used NADH rather than the NADPH used by Helicobacter, and two recombinant Entamoeba nitroreductases increased the metronidazole sensitivity of transformed Escherichia coli strains. Conversely, the recombinant nitroimidazole reductases (NIMs) of Entamoeba and Trichmonas conferred very strong metronidazole resistance to transformed bacteria. The Ehntr1 gene of the genome project HM-1:IMSS strain of Entamoeba histolytica had a nonsense mutation, and the same nonsense mutation was present in 3 of 22 clinical isolates of Entamoeba. While ntr and nim mRNAs were variably expressed by cultured Entamoeba and Trichomonas isolates, there was no relationship to metronidazole sensitivity. We conclude that microaerophilic protists have bacterium-like enzymes capable of activating metronidazole (nitroreductases) and inactivating metronidazole (NIMs). While Entamoeba and Trichomonas displayed some of the changes (nonsense mutations and gene overexpression) associated with metronidazole resistance in bacteria, these changes did not confer metronidazole resistance to the microaerophilic protists examined here.

  2. Biomimetic sensor based on molecularly imprinted polymer with nitroreductase-like activity for metronidazole detection.

    PubMed

    Gu, Yue; Yan, Xiaoyi; Li, Cong; Zheng, Bo; Li, Yaru; Liu, Weilu; Zhang, Zhiquan; Yang, Ming

    2016-03-15

    The utility of molecularly imprinted polymer (MIP) as electrochemical sensor often suffers from its limited catalytic efficiency. Here, we proposed an alternative approach by combining the concept of MIP with the use of mimetic enzyme. A metronidazole imprinted polymer with nitroreductase-like activity was successfully achieved via an electrochemical method, where melamine served two purposes: functional monomer of MIP and component of mimetic enzyme. During the imprinting process, the redox-active center, which is responsible for catalysis, was introduced into the imprinted cavities. Accordingly, the imprinted polymer, having both catalysis centers and recognition sites, exhibited enhanced electrocatalytic activity and selectivity. The sensing performances of this metronidazole imprinted biomimetic sensor were evaluated in detail. Results revealed that the response to metronidazole was linear in the concentration range of 0.5-1000 μM, and the detection limit was 0.12 μM (S/N=3). In addition, we applied the proposed sensor to detect metronidazole in an injection solution and the results implied its feasibility for practical application. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Structure of RdxA: an oxygen insensitive nitroreductase essential for metronidazole activation in Helicobacter pylori

    PubMed Central

    Martínez-Júlvez, Marta; Rojas, Adriana L.; Olekhnovich, Igor; Angarica, Vladimir Espinosa; Hoffman, Paul S.; Sancho, Javier

    2012-01-01

    The RdxA oxygen insensitive nitroreductase of the human gastric pathogen Helicobacter pylori is responsible for the susceptibility of this organism to the redox active prodrug metronidazole (MTZ). Loss-of-function mutations in rdxA are primarily responsible for resistance to this therapeutic. RdxA exhibits potent NADPH oxidase activity under aerobic conditions and metronidazole reductase activity under strictly anaerobic conditions. Here we report the crystal structure of RdxA, which is a homodimer exhibiting domain swapping and containing two molecules of FMN bound at the dimer interface. We have found a gap between the side chain of Tyr47 and the isoalloxazine ring of FMN that seems appropriate for substrate binding. The structure does not include residues 97–128, which corresponds to a locally unstable part of the NTR from E. coli, and might be involved in cofactor binding. Comparison of H pylori RdxA to other oxidoreductases of known structure suggests RdxA may belong to a new subgroup of oxidoreductases in which a cysteine sidechain close to the FMN cofactor could be involved in the reductive activity. In this respect, mutation of C159 to A or S (C159A/S) has resulted in loss of MTZ reductase activity, but not NADPH oxidase activity. The RdxA structure allows interpretation of the many loss-of-function mutations previously described, including those affecting C159, a residue whose interaction with FMN is required for nitroreduction of MTZ. Our studies provide unique insights into the redox behavior of the flavin in this key enzyme for metronidazole activation, and with potential use in gene therapy. PMID:23039228

  4. Lon protease affects the RdxA nitroreductase activity and metronidazole susceptibility in Helicobacter pylori.

    PubMed

    Tu, I-Fan; Liao, Jiahn-Haur; Yang, Feng-Ling; Lin, Nien-Tsung; Chan, Hong-Lin; Wu, Shih-Hsiung

    2014-10-01

    The lon gene of Helicobacter pylori strains is constitutively expressed during growth. However, virtually nothing is understood concerning the role of Lon in H. pylori. This study examined the function and physiological role of Lon in H. pylori (HpLon) using a trapping approach to identify putative Lon binding partners in the bacterium. Protease-deficient Lon was expressed and served as the bait in trapping approach to capture the interacting partners in H. pylori. The antibiotic susceptibility of wild-type and lon derivative mutants was determined by the E test trips and the disc diffusion assay. The effect of HpLon on RdxA activity was detected the change in NADPH oxidation and metronidazole reduction by spectrophotometer. Lon in Helicobacter pylori (HpLon) interacting partners are mostly associated with metronidazole activation. lon mutant presents more susceptible to metronidazole than that of the wild type, and this phenotype is recovered by complementation of the wild-type Lon. We found that the ATPases associated with a variety of cellular activities (AAA(+) ) module of HpLon causes a decrease in both NADPH oxidase and Mtz reductase activity in RdxA, a major Mtz-activating enzyme in H. pylori. Metronidazole resistance of H. pylori causes the serious medical problem worldwide. In this study, HpLon is involved in metronidazole susceptibility among H. pylori strains. We provide the evidence that HpLon alters RdxA activity in vitro. The decrease in metronidazole activation caused by HpLon is possibly prior to accumulate mutation in rdxA gene before the metronidazole-resistant strains to be occurred. © 2014 John Wiley & Sons Ltd.

  5. [Frequency of Helicobacter pylori nitroreductase RdxA mutations for metronidazole activation in a population in the Cauca Department, Colombia].

    PubMed

    Acosta, Claudia Patricia; Quiroga, Andrés Javier; Sierra, Carlos H; Trespalacios, Alba Alicia

    2017-06-01

    Resistance to metronidazole is a key factor associated with Helicobacter pylori treatment failure. Even though resistance is mostly associated with RdxA nitroreductase mutations, studies of this H. pylori protein in Popayán (Colombia) are still incipient. To evaluate the frequency of mutations in the RdxA nitroreductase in a population of patients with H. pylori-positive gastrointestinal disease. We amplified the DNA of 170 gastric biopsies by PCR to detect mutations in the RdxA nitroreductase. An analysis of DNA sequences translated into amino acid sequences was done and then compared to the reference strain 26695. The frequency of RdxA nitroreductase mutations in this study population was 78%. Its most frequent distribution was found in positions D59N (153 samples), R131K (101 samples), R90K (97 samples), A118T (42 samples), I160F (32 samples) and H97T (26 samples), and meaningful stop codons Q50*, D59*; E75*, C159* and I160* in five, one, three, ten and six samples, respectively. The most common virulence genotype was vacAs1/m1 cagA negative (48.6 %). The high frequency of RdxA nitroreductase mutations in H. pylori isolates in Popayán (Colombia) indicates that empirical therapy with metronidazole may not be a valid option for the eradication of H. pylori in patients of the studied population.

  6. Characterization of the NAD(P)H Oxidase and Metronidazole Reductase Activities of the RdxA Nitroreductase of Helicobacter pylori

    PubMed Central

    Olekhnovich, Igor N.; Goodwin, Avery; Hoffman, Paul S.

    2009-01-01

    Metronidazole (MTZ) is widely used in combination therapies against the human gastric pathogen Helicobacter pylori. Resistance to this drug is common among clinical isolates and results from loss of function mutations in rdxA, which encodes an oxygen insensitive nitroreductase (NTR). The RdxA-associated MTZ-reductase activity of H. pylori is lost upon cell disruption. Here we provide a mechanistic explanation for this phenomenon. Under aerobic conditions, His6-tagged RdxA protein (purified from Escherichia coli), catalyzed NAD(P)H-dependent reductions of nitroaromatic and quinone substrates including: nitrofurazone, nitrofurantoin, furazolidone, CB1954, and 1,4 benzoquinone, but not MTZ. Unlike other NTRs, His6-RdxA exhibited potent NAD(P)H oxidase activity (kcat = 2.8 s−1) which suggested two possible explanations for the role of oxygen in MTZ reduction: 1) NAD(P)H oxidase activity promotes cellular hypoxia (nonspecific reduction of MTZ); and 2) molecular oxygen out-competes MTZ for reducing equivalents. The first hypothesis was eliminated upon finding that rdxA expression, while increasing MTZ toxicity in both E. coli and H. pylori constructs, did not increase paraquat toxicity even though both are of similar redox potential. The second hypothesis was confirmed by demonstrating NAD(P)H-dependent MTZ-reductase activity (apparent Km = 122 ± 58 μM, kcat = 0.24 s−1) under strictly anaerobic conditions. The MTZ reductase activity of RdxA was 60-times greater than for NfsB (E. coli NTR), but 10 times lower than the NADPH-oxidase activity. Whether molecular oxygen directly competes with MTZ or alters the redox state of the FMN cofactors is discussed. PMID:19438716

  7. Comparative characterisation of two nitroreductases from Giardia lamblia as potential activators of nitro compounds.

    PubMed

    Müller, Joachim; Rout, Samuel; Leitsch, David; Vaithilingam, Jathana; Hehl, Adrian; Müller, Norbert

    2015-08-01

    Giardia lamblia is a protozoan parasite that causes giardiasis, a diarrhoeal disease affecting humans and various animal species. Nitro drugs such as the nitroimidazole metronidazole and the nitrothiazolide nitazoxanide are used for treatment of giardiasis. Nitroreductases such as GlNR1 and GlNR2 may play a role in activation or inactivation of these drugs. The aim of this work is to characterise these two enyzmes using functional assays. For respective analyses recombinant analogues from GlNR1 and GlNR2 were produced in Escherichia coli. E. coli expressing GlNR1 and GlNR2 alone or together were grown in the presence of nitro compounds. Furthermore, pull-down assays were performed using HA-tagged GlNR1 and GlNR2 as baits. As expected, E. coli expressing GlNR1 were more susceptible to metronidazole under aerobic and semi-aerobic and to nitazoxanide under semi-aerobic growth conditions whereas E. coli expressing GlNR2 were susceptible to neither drug. Interestingly, expression of both nitroreductases gave the same results as expression of GlNR2 alone. In functional assays, both nitroreductases had their strongest activities on the quinone menadione (vitamin K3) and FAD, but reduction of nitro compounds including the nitro drugs metronidazole and nitazoxanide was clearly detected. Full reduction of 7-nitrocoumarin to 7-aminocoumarin was preferentially achieved with GlNR2. Pull-down assays revealed that GlNR1 and GlNR2 interacted in vivo forming a multienzyme complex. These findings suggest that both nitroreductases are multifunctional. Their main biological role may reside in the reduction of vitamin K analogues and FAD. Activation by GlNR1 or inactivation by GlNR2 of nitro drugs may be the consequence of a secondary enzymatic activity either yielding (GlNR1) or eliminating (GlNR2) toxic intermediates after reduction of these compounds.

  8. Nitroreductase-triggered activation of a novel caged fluorescent probe obtained from methylene blue.

    PubMed

    Bae, Jungeun; McNamara, Louis E; Nael, Manal A; Mahdi, Fakhri; Doerksen, Robert J; Bidwell, Gene L; Hammer, Nathan I; Jo, Seongbong

    2015-08-18

    A near-infrared fluorescent probe based on methylene blue (p-NBMB) was developed for the detection of nitroreductase. Conjugating methylene blue with a p-nitrobenzyl moiety enables it to be activated by nitroreductase-catalyzed 1,6-elimination, resulting in the release of an active methylene blue fluorophore.

  9. Trichomonas vaginalis Metronidazole Resistance Is Associated with Single Nucleotide Polymorphisms in the Nitroreductase Genes ntr4Tv and ntr6Tv

    PubMed Central

    Paulish-Miller, Teresa E.; Augostini, Peter; Schuyler, Jessica A.; Smith, William L.; Mordechai, Eli; Adelson, Martin E.; Gygax, Scott E.; Secor, William E.

    2014-01-01

    Metronidazole resistance in the sexually transmitted parasite Trichomonas vaginalis is a problematic public health issue. We have identified single nucleotide polymorphisms (SNPs) in two nitroreductase genes (ntr4Tv and ntr6Tv) associated with resistance. These SNPs were associated with one of two distinct T. vaginalis populations identified by multilocus sequence typing, yet one SNP (ntr6Tv A238T), which results in a premature stop codon, was associated with resistance independent of population structure and may be of diagnostic value. PMID:24550324

  10. Contingency nature of Helicobacter bizzozeronii oxygen-insensitive NAD(P)H-nitroreductase (HBZC1_00960) and its role in metronidazole resistance

    PubMed Central

    2013-01-01

    Genomic analysis of a metronidazole resistant H. bizzozeronii strain revealed a frame length extension of the oxygen-insensitive NAD(P)H-nitroreductase HBZC1_00960 (RdxA), associated with the disruption of the C-terminal cysteine-containing conserved region (IACLXALGK). This was the result of the extension (from C8 to C9) of a simple sequence cytosine repeat (SSCR) located in the 3’ of the gene. A 3' SSCR is also present in the rdxA homolog of H. heilmannii sensu stricto, but not in H. pylori. We showed that in the majority of in vitro spontaneous H. bizzozeronii metronidazole resistant mutants, the extension of the 3′ SSCR of rdxA was the only mutation observed. In addition, we observed that H. bizzozeronii ΔrdxA mutant strain showed the same MIC value of metronidazole observed in the spontaneous mutants. These data indicate that loss of function mutations in rdxA and in particular the disruption of the conserved region IACLXALGK is associated with reduced susceptibility to metronidazole in H. bizzozeronii. Slipped-strand mispairing of the SSCR located in the 3′ of the H. bizzozeronii rdxA appears to be the main mechanism. We also observed that H. bizzozeronii acquires resistance to metronidazole at high mutation rate, and that serial passages in vitro without selection induced an increased level of susceptibility. In conclusion, contrary to what was previously described in H. pylori, the H. bizzozeronii rdxA appears to be a contingency gene which undergoes phase variation. The contingency nature of rdxA should be carefully considered when metronidazole is used in the treatment of H. heilmannii-associated gastritis. PMID:23865636

  11. Application of a Microfluidic Reactor for Screening Cancer Prodrug Activation Using Silica-Immobilized Nitrobenzene Nitroreductase

    DTIC Science & Technology

    2006-01-01

    the corresponding electron- donating hydroxylamine is useful in a variety of biotechnological applications. Activation of prodrugs for cancer...withdrawing nitro group to the correspond- ing electron-donating hydroxylamine results in a very large electronic change, providing an effective enzyme... hydroxylamine derivative by bacterial nitroreductases.2-4 DEPT using Escherichia coli ni- troreductase and CB1954 has been demonstrated to be an

  12. Resistance to nitrophenolic herbicides and metronidazole in the cyanobacterium Synechocystis sp. PCC 6803 as a result of the inactivation of a nitroreductase-like protein encoded by drgA gene.

    PubMed

    Elanskaya, I V; Chesnavichene, E A; Vernotte, C; Astier, C

    1998-05-29

    Dinoseb is a herbicide known to inhibit photosystem II electron transfer like DCMU, triazine and phenolic-type herbicides. The mutant Din7 of the cyanobacterium Synechocystis sp. PCC 6803, selected for resistance to dinoseb, and the mutant Ins2, constructed by the insertion of the kanamycin resistance cassette into the drgA gene, were cross-resistant to other nitrophenolic herbicides (DNOC, 2,4-dinitrophenol) and to the cell inhibitor metronidazole but not to the photosystem II inhibitors DCMU or ioxynil. The Din7 mutant had the same characteristics of photosystem II inhibition by dinoseb as the wild type. This result suggested the existence of another site for dinoseb inhibition. The wild type cells modified dinoseb to a non-toxic product that gave an absorption spectrum similar to that of dithionite treated dinoseb containing reduced nitro groups. In contrast, the Din7 mutant did not modify dinoseb. These phenomena were controlled by the drgA gene encoding a protein which showed similarity to several enzymes having nitroreductase activity. The addition of superoxide dismutase to the medium relieved the toxic effect of dinoseb in wild type cells but not in Din7. It is proposed that in wild type cells of Synechocystis sp. PCC 6803 the DrgA protein is involved in detoxification of dinoseb via the reduction of the nitro group(s) and this process is accompanied by the formation of toxic superoxide anions. Mutations blocking the activity of the DrgA protein lead to the development of resistance to nitrophenolic herbicides and metronidazole.

  13. Nifurtimox Activation by Trypanosomal Type I Nitroreductases Generates Cytotoxic Nitrile Metabolites*

    PubMed Central

    Hall, Belinda S.; Bot, Christopher; Wilkinson, Shane R.

    2011-01-01

    The prodrug nifurtimox has been used for more than 40 years to treat Chagas disease and forms part of a recently approved combinational therapy that targets West African trypanosomiasis. Despite this, its mode of action is poorly understood. Detection of reactive oxygen and nitrogen intermediates in nifurtimox-treated extracts led to the proposal that this drug induces oxidative stress in the target cell. Here, we outline an alternative mechanism involving reductive activation by a eukaryotic type I nitroreductase. Several enzymes proposed to metabolize nifurtimox, including prostaglandin F2α synthase and cytochrome P450 reductase, were overexpressed in bloodstream-form Trypanosoma brucei. Only cells with elevated levels of the nitroreductase displayed altered susceptibility to this nitrofuran, implying a key role in drug action. Reduction of nifurtimox by this enzyme was shown to be insensitive to oxygen and yields a product characterized by LC/MS as an unsaturated open-chain nitrile. This metabolite was shown to inhibit both parasite and mammalian cell growth at equivalent concentrations, in marked contrast to the parental prodrug. These experiments indicate that the basis for the selectivity of nifurtimox against T. brucei lies in the expression of a parasite-encoded type I nitroreductase. PMID:21345801

  14. Transcriptomics Indicates Active and Passive Metronidazole Resistance Mechanisms in Three Seminal Giardia Lines

    PubMed Central

    Ansell, Brendan R. E.; Baker, Louise; Emery, Samantha J.; McConville, Malcolm J.; Svärd, Staffan G.; Gasser, Robin B.; Jex, Aaron R.

    2017-01-01

    Giardia duodenalis is an intestinal parasite that causes 200–300 million episodes of diarrhoea annually. Metronidazole (Mtz) is a front-line anti-giardial, but treatment failure is common and clinical resistance has been demonstrated. Mtz is thought to be activated within the parasite by oxidoreductase enzymes, and to kill by causing oxidative damage. In G. duodenalis, Mtz resistance involves active and passive mechanisms. Relatively low activity of iron-sulfur binding proteins, namely pyruvate:ferredoxin oxidoreductase (PFOR), ferredoxins, and nitroreductase-1, enable resistant cells to passively avoid Mtz activation. Additionally, low expression of oxygen-detoxification enzymes can allow passive (non-enzymatic) Mtz detoxification via futile redox cycling. In contrast, active resistance mechanisms include complete enzymatic detoxification of the pro-drug by nitroreductase-2 and enhanced repair of oxidized biomolecules via thioredoxin-dependent antioxidant enzymes. Molecular resistance mechanisms may be largely founded on reversible transcriptional changes, as some resistant lines revert to drug sensitivity during drug-free culture in vitro, or passage through the life cycle. To comprehensively characterize these changes, we undertook strand-specific RNA sequencing of three laboratory-derived Mtz-resistant lines, 106-2ID10, 713-M3, and WB-M3, and compared transcription relative to their susceptible parents. Common up-regulated genes encoded variant-specific surface proteins (VSPs), a high cysteine membrane protein, calcium and zinc channels, a Mad-2 cell cycle regulator and a putative fatty acid α-oxidase. Down-regulated genes included nitroreductase-1, putative chromate and quinone reductases, and numerous genes that act proximal to PFOR. Transcriptional changes in 106-2ID10 diverged from those in 713-r and WB-r (r ≤ 0.2), which were more similar to each other (r = 0.47). In 106-2ID10, a nonsense mutation in nitroreductase-1 transcripts could enhance passive

  15. [Metronidazole].

    PubMed

    Martinez, V; Caumes, E

    2001-09-01

    Metronidazole was first introduced for the treatment of trichomoniasis. Now, its therapeutics use has subsequently been expanded to include protozoal and anaerobic infections. Oral administration is recommended: rosacea, perioral dermatitis, Helicobacter pylori, Trichomonas vaginalis and Giardia lamblia infections and bacterial vaginosis. Metronidazole given orally is absorbed almost completely. Metronidazole has limited plasma protein binding but can reach very favourable tissue distribution, including central nervous system and placenta. This drug is extensively metabolised by the liver to form 5 oxydative metabolites. The majority of this drug and metabolites are excreted in urine and feces. The half-life is 6 to 10 hours. The recommended dose is 500 mg three time per day and an adaptation is necessary in renal insufficiency. Metronidazole is well tolerated when administered in dosages of less than 2 g per day. Some adverse reactions appear to be related to the high dosages and treatment duration. Drug interactions with alcohol, warfarin and phenytoin have been reported. Mutagenesis and cancerogenesis is only described in mouse. Resistance, both clinical and microbiological, has been described only rarely.

  16. Activation of Benznidazole by Trypanosomal Type I Nitroreductases Results in Glyoxal Formation

    PubMed Central

    Hall, Belinda S.

    2012-01-01

    Benznidazole, a 2-nitroimidazole, is the front-line treatment used against American trypanosomiasis, a parasitic infection caused by Trypanosoma cruzi. Despite nearly 40 years of use, the trypanocidal activity of this prodrug is not fully understood. It has been proposed that benznidazole activation leads to the formation of reductive metabolites that can cause a series of deleterious effects, including DNA damage and thiol depletion. Here, we show that the key step in benznidazole activation involves an NADH-dependent trypanosomal type I nitroreductase. This catalyzes an oxygen-insensitive reaction with the interaction of enzyme, reductant, and prodrug occurring through a ping-pong mechanism. Liquid chromatography/mass spectrometry (LC/MS) analysis of the resultant metabolites identified 4,5-dihydro-4,5-dihydroxyimidazole as the major product of a reductive pathway proceeding through hydroxylamine and hydroxy intermediates. The breakdown of this product released the reactive dialdehyde glyoxal, which, in the presence of guanosine, generated guanosine-glyoxal adducts. These experiments indicate that the reduction of benznidazole by type I nitroreductase activity leads to the formation of highly reactive metabolites and that the expression of this enzyme is key to the trypanocidal properties displayed by the prodrug. PMID:22037852

  17. APPLICATION OF 6-NITROCOUMARIN AS A SUBSTRATE FOR THE FLUORESCENT DETECTION OF NITROREDUCTASE ACTIVITY IN Sporothrix schenckii

    PubMed Central

    Stopiglia, Cheila Denise Ottonelli; Carissimi, Mariana; Daboit, Tatiane Caroline; Stefani, Valter; Corbellini, Valeriano Antonio; Scroferneker, Maria Lúcia

    2013-01-01

    Introduction Sporothrix schenckii is a thermal dimorphic pathogenic fungus causing a subcutaneous mycosis, sporotrichosis. Nitrocoumarin represents a fluorogenic substrate class where the microbial nitroreductase activity produces several derivatives, already used in several other enzyme assays. The objective of this study was the analysis of 6-nitrocoumarin (6-NC) as a substrate to study the nitroreductase activity in Sporothrix schenckii. Methods Thirty-five samples of S. schenckii were cultivated for seven, 14 and 21 days at 35 °C in a microculture containing 6-nitrocoumarin or 6-aminocoumarin (6-AC) dissolved in dimethyl sulfoxide or dimethyl sulfoxide as a negative control, for posterior examination under an epifluorescence microscope. The organic layer of the seven, 14 and 21-day cultures was analyzed by means of direct illumination with 365 nm UV light and by means of elution on G silica gel plate with hexane:ethyl acetate 1:4 unveiled with UV light. Results All of the strains showed the presence of 6-AC (yellow fluorescence) and 6-hydroxylaminocoumarin (blue fluorescence) in thin layer chromatography, which explains the green fluorescence observed in the fungus structure. Conclusion The nitroreductase activity is widely distributed in the S. schenckii complex and 6-NC is a fluorogenic substrate of easy access and applicability for the nitroreductase activity detection. PMID:24037291

  18. Metronidazole-triazole conjugates: activity against Clostridium difficile and parasites.

    PubMed

    Jarrad, Angie M; Karoli, Tomislav; Debnath, Anjan; Tay, Chin Yen; Huang, Johnny X; Kaeslin, Geraldine; Elliott, Alysha G; Miyamoto, Yukiko; Ramu, Soumya; Kavanagh, Angela M; Zuegg, Johannes; Eckmann, Lars; Blaskovich, Mark A T; Cooper, Matthew A

    2015-08-28

    Metronidazole has been used clinically for over 50 years as an antiparasitic and broad-spectrum antibacterial agent effective against anaerobic bacteria. However resistance to metronidazole in parasites and bacteria has been reported, and improved second-generation metronidazole analogues are needed. The copper catalysed Huigsen azide-alkyne 1,3-dipolar cycloaddition offers a way to efficiently assemble new libraries of metronidazole analogues. Several new metronidazole-triazole conjugates (Mtz-triazoles) have been identified with excellent broad spectrum antimicrobial and antiparasitic activity targeting Clostridium difficile, Entamoeba histolytica and Giardia lamblia. Cross resistance to metronidazole was observed against stable metronidazole resistant C. difficile and G. lamblia strains. However for the most potent Mtz-triazoles, the activity remained in a therapeutically relevant window. Copyright © 2015 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

  19. Metronidazole-triazole conjugates: Activity against Clostridium difficile and parasites

    PubMed Central

    Jarrad, Angie M.; Karoli, Tomislav; Debnath, Anjan; Tay, Chin Yen; Huang, Johnny X.; Kaeslin, Geraldine; Elliott, Alysha G.; Miyamoto, Yukiko; Ramu, Soumya; Kavanagh, Angela M.; Zuegg, Johannes; Eckmann, Lars; Blaskovich, Mark A.T.; Cooper, Matthew A.

    2015-01-01

    Metronidazole has been used clinically for over 50 years as an antiparasitic and broad-spectrum antibacterial agent effective against anaerobic bacteria. However resistance to metronidazole in parasites and bacteria has been reported, and improved second-generation metronidazole analogues are needed. The copper catalysed Huigsen azide-alkyne 1,3-dipolar cycloaddition offers a way to efficiently assemble new libraries of metronidazole analogues. Several new metronidazole-triazole conjugates (Mtz-triazoles) have been identified with excellent broad spectrum antimicrobial and antiparasitic activity targeting Clostridium difficile, Entamoeba histolytica and Giardia lamblia. Cross resistance to metronidazole was observed against stable metronidazole resistant C. difficile and G. lamblia strains. However for the most potent Mtz-triazoles, the activity remained in a therapeutically relevant window. PMID:26117821

  20. Concentrations and in vivo antibacterial activity of spiramycin and metronidazole in patients with periodontitis treated with high-dose metronidazole and the spiramycin/metronidazole combination.

    PubMed

    Poulet, Pierre-Pascal; Duffaut, Danielle; Barthet, Pierre; Brumpt, Ivan

    2005-03-01

    Previous studies have shown that metronidazole, alone or in combination with spiramycin (250 mg/1 500 000 units, three times/day), is an effective treatment for active periodontitis, although the dose of metronidazole currently used (750 mg/day) could provide concentrations in gingival crevice fluid that are too low for the MICs of the involved pathogens. This study tested the in vivo antibacterial efficacy of the currently used metronidazole dose (as contained in the fixed spiramycin/metronidazole combination) in patients with an active periodontitis, and of a high dose (1500 mg/day) of metronidazole alone. We measured the MICs of spiramycin and metronidazole for the recovered pathogens and the gingival crevice fluid antibiotic concentrations of both antibiotics, and attempted to correlate them with bacterial eradication. The concentrations of metronidazole consistently exceeded the MICs for the pathogens isolated in the corresponding sites, even at the usual metronidazole (250 mg three times/day) dose. All the bacterial species were eradicated during treatment and at follow-up, although Fusobacterium spp. eradicated during treatment reappeared in a majority of the cases at follow-up, 30 days after treatment, in both groups. The results of antibiotic therapy with metronidazole or the spiramycin/metronidazole combination are consistent with their in vitro antibacterial activity and with the local antibiotic concentrations; they suggest that the currently used metronidazole dose (250 mg, three times/day) alone or as part of the spiramycin/metronidazole combination, could be sufficient for the treatment of active periodontitis.

  1. Activation of Bicyclic Nitro-drugs by a Novel Nitroreductase (NTR2) in Leishmania

    PubMed Central

    Patterson, Stephen; Read, Kevin D.

    2016-01-01

    Drug discovery pipelines for the “neglected diseases” are now heavily populated with nitroheterocyclic compounds. Recently, the bicyclic nitro-compounds (R)-PA-824, DNDI-VL-2098 and delamanid have been identified as potential candidates for the treatment of visceral leishmaniasis. Using a combination of quantitative proteomics and whole genome sequencing of susceptible and drug-resistant parasites we identified a putative NAD(P)H oxidase as the activating nitroreductase (NTR2). Whole genome sequencing revealed that deletion of a single cytosine in the gene for NTR2 that is likely to result in the expression of a non-functional truncated protein. Susceptibility of leishmania was restored by reintroduction of the wild-type gene into the resistant line, which was accompanied by the ability to metabolise these compounds. Overexpression of NTR2 in wild-type parasites rendered cells hyper-sensitive to bicyclic nitro-compounds, but only marginally to the monocyclic nitro-drugs, nifurtimox and fexinidazole sulfone, known to be activated by a mitochondrial oxygen-insensitive nitroreductase (NTR1). Conversely, a double knockout NTR2 null cell line was completely resistant to bicyclic nitro-compounds and only marginally resistant to nifurtimox. Sensitivity was fully restored on expression of NTR2 in the null background. Thus, NTR2 is necessary and sufficient for activation of these bicyclic nitro-drugs. Recombinant NTR2 was capable of reducing bicyclic nitro-compounds in the same rank order as drug sensitivity in vitro. These findings may aid the future development of better, novel anti-leishmanial drugs. Moreover, the discovery of anti-leishmanial nitro-drugs with independent modes of activation and independent mechanisms of resistance alleviates many of the concerns over the continued development of these compound series. PMID:27812217

  2. Reduction of beta-glucuronidase and nitroreductase activity by yoghurt in a murine colon cancer model.

    PubMed

    de Moreno de LeBlanc, A; Perdigón, G

    2005-04-01

    Yoghurt feeding inhibits induced colon cancer in mice. Several studies showed the immunomodulatory effect of yoghurt which can explain this inhibition. It is possible that yoghurt bacteria can also affect gut flora enzymes related to colon carcinogenesis as reported for other probiotics in different animal tumours. The aim of this work was to evaluate the role of yoghurt starter bacteria and their cell-free fermentation products on the reduction of procarcinogen enzyme activities (beta-glucuronidase and nitroreductase). Mice injected with 1,2-dimethylhydrazine (DMH) and fed with yoghurt were used for this study. Mice given milk or yoghurt supernatant (cell free extract) were used to evaluate if the yoghurt antitumour effect is due to the starter bacteria or other components released during fermentation, that could inhibit these enzymes. We determined that yoghurt by itself maintained enzymes activities similar or lower than non-treatment control group, and the enzyme activity was also lower than milk or yoghurt supernatant groups. DMH increased the activity of the enzymes. Mice injected with DMH and fed cyclically with yoghurt presented lower enzymes activities than the tumour control group. Feeding yoghurt decreased procarcinogenic enzyme levels in the large intestine contents of mice bearing colon tumour. The results of this study provide another mechanism by which yoghurt starter bacteria interact with the large intestine of the mice and prevent colon cancer.

  3. Metronidazole activation and isolation of Clostridium acetobutylicum electron transport genes.

    PubMed Central

    Santangelo, J D; Jones, D T; Woods, D R

    1991-01-01

    An Escherichia coli F19 recA, nitrate reductase-deficient mutant was constructed by transposon mutagenesis and shown to be resistant to metronidazole. This mutant was a most suitable host for the isolation of Clostridium acetobutylicum genes on recombinant plasmids, which activated metronidazole and rendered the E. coli F19 strain sensitive to metronidazole. Twenty-five E. coli F19 clones containing different recombinant plasmids were isolated and classified into five groups on the basis of their sensitivity to metronidazole. The clones were tested for nitrate reductase, pyruvate-ferredoxin oxidoreductase, and hydrogenase activities. DNA hybridization and restriction endonuclease mapping revealed that four of the C. acetobutylicum insert DNA fragments on recombinant plasmids were linked in an 11.1-kb chromosomal fragment. DNA sequencing and amino acid homology studies indicated that this DNA fragment contained a flavodoxin gene which encoded a protein of 160 amino acids that activated metronidazole and made the E. coli F19 mutant very sensitive to metronidazole. The flavodoxin and hydrogenase genes which are involved in electron transfer systems were linked on the 11.1-kb DNA fragment from C. acetobutylicum. Images PMID:1991710

  4. Effects of metronidazole and its metabolites on histamine immunosuppression activity.

    PubMed

    Elizondo, G; Ostrosky-Wegman, P

    1996-01-01

    We have previously reported that metronidazole treatment increases human lymphocyte proliferation showing individual differences. This drug and its metabolites are imidazole compounds like histamine and cimetidine. The first is an endogenous amine that inhibits T-helper lymphocyte proliferation, and the second is a histamine antagonist. We presently report the in vitro effects of histamine, cimetidine, imidazole, metronidazole and its two principal metabolites (the acetic acid and hydroxy forms), on the mitogenic response to phytohemagglutinin (PHA) stimulation of human peripheral blood lymphocytes. Histamine decreased lymphocyte proliferation while (in order of potency) cimetidine, the hydroxy metabolite of metronidazole, imidazole and metronidazole, increased the mitogenic response to PHA in a dose-response fashion. The acetic acid metabolite lacked immunomodulatory effects. Competitive studies showed that cimetidine, metronidazole, and the hydroxy metabolite blocked the inhibitory effect of histamine on lymphocyte proliferation in a dose-related manner. This blockage was non-competitive, suggesting that the target of the imidazole compounds was not the active site of the H2 receptor.

  5. [Metronidazole effect on active oxygen production by human blood neutrophils].

    PubMed

    Shchepetkin, I A

    1997-01-01

    The in vitro effect of metronidazole on production of active oxygen by neutrophila and in the enzymatic system of glucose-glucose oxidase-peroxidase was studied by luminol-dependent chemiluminescence. An increase in the spontaneous and zymozan-stimulated chemiluminescence and a decrease in the phorbolmyristate acetate (PMA)-stimulated chemiluminescence after 2-hour preincubation of the neutrophils with 8.5 mM of metronidazole were observed. In concentrations of 0.9 to 8.7 mM metronidazole (without washing) dose-dependently lowered the neutrophil chemiluminescence in response to the effect of PMA and ionophore A23187 and to a lesser degree to that of zymozan. In doses of 20 to 100 mM the drug had an insignificant effect on production of active oxygen by the neutrophils in response to the cell stimulation by PMA, ionophore A23187 and zymozan. The data are in conformity with the scavenger effect of metronidazole on active oxygen radicals generating in the cell-free enzymatic system both in the presence and in the absence of superoxide dismutase.

  6. The aerobic activity of metronidazole against anaerobic bacteria.

    PubMed

    Dione, Niokhor; Khelaifia, Saber; Lagier, Jean-Christophe; Raoult, Didier

    2015-05-01

    Recently, the aerobic growth of strictly anaerobic bacteria was demonstrated using antioxidants. Metronidazole is frequently used to treat infections caused by anaerobic bacteria; however, to date its antibacterial activity was only tested in anaerobic conditions. Here we aerobically tested using antioxidants the in vitro activities of metronidazole, gentamicin, doxycycline and imipenem against 10 common anaerobic and aerobic bacteria. In vitro susceptibility testing was performed by the disk diffusion method, and minimum inhibitory concentrations (MICs) were determined by Etest. Aerobic culture of the bacteria was performed at 37°C using Schaedler agar medium supplemented with 1mg/mL ascorbic acid and 0.1mg/mL glutathione; the pH was adjusted to 7.2 by 10M KOH. Growth of anaerobic bacteria cultured aerobically using antioxidants was inhibited by metronidazole after 72h of incubation at 37°C, with a mean inhibition diameter of 37.76mm and an MIC of 1μg/mL; however, strains remained non-sensitive to gentamicin. No growth inhibition of aerobic bacteria was observed after 24h of incubation at 37°C with metronidazole; however, inhibition was observed with doxycycline and imipenem used as controls. These results indicate that bacterial sensitivity to metronidazole is not related to the oxygen tension but is a result of the sensitivity of the micro-organism. In future, both culture and antibiotic susceptibility testing of strictly anaerobic bacteria will be performed in an aerobic atmosphere using antioxidants in clinical microbiology laboratories. Copyright © 2015 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  7. Effects of metronidazole on hepatic CYP3A4 activity.

    PubMed

    Haas, C E; Kaufman, D C; DiCenzo, R C

    2001-10-01

    To evaluate the effect of a short course of oral metronidazole, commonly used for bowel-preparation regimens, on hepatic cytochrome P450 (CYP) 3A4 activity, as measured by the [14C N-methyl]-erythromycin breath test (ERMBT) in healthy volunteers. Prospective, nonrandomized, interventional study University-affiliated, community, teaching hospital. Five healthy male volunteers. Subjects underwent a baseline ERMBT in the morning before receiving three oral doses of metronidazole 500 mg administered at 3 P.M., 7 P.M., and 11 P.M. Repeat ERMBTs were performed at 24, 72, and 96 hours after the initial ERMBT. Changes in ERMBT values were compared with baseline results using Freidman's repeated-measures analysis of variance on ranks. The ERMBT values did not change significantly compared with baseline (p=0.82). Median (range) ERMBT values expressed as a percentage of baseline at 24, 72, and 96 hours were 110.3 (96.2-136.9), 101.3 (99.3-115.0), and 101.8 (95.5-116.3), respectively A short course of oral metronidazole does not result in a significant change in hepatic CYP3A4 activity as measured by the ERMBT.

  8. 2-(Nitroaryl)benzothiazole and benzoxazole derivatives as fluorogenic substrates for the detection of nitroreductase activity in clinically important microorganisms.

    PubMed

    Cellier, Marie; Gignoux, Amandine; James, Arthur L; Orenga, Sylvain; Perry, John D; Robinson, Shaun N; Stanforth, Stephen P; Turnbull, Graeme

    2015-12-15

    A series of carboxy-substituted 2-(nitroaryl)benzothiazole derivatives and carboxy-substituted 2-(nitroaryl)benzoxazole derivatives were prepared and evaluated as potential nitroreductase substrates for the purpose of detecting clinically important microorganisms. Several of the substrates produced highly fluorescent colonies with the majority of a panel of 10 Gram-negative bacteria and also with two of a panel of 8 Gram-positive bacteria.

  9. Application of Salmonella strains with altered nitroreductase and O-acetyltransferase activities to the evaluation of the mutagenicity of airborne particles.

    PubMed

    Adamiak, W; Jadczyk, P; Kucharczyk, J

    1999-01-01

    The Ames test was applied to evaluation of the mutagenicity of month's samples of airborne particles from the center of Wrocław (SW Poland) collected in August and December 1997. The strains used for the study were TA 98, TA 100 and their derivatives: TA 98 NR, YG 1021, YG 1024, YG 1026, YG 1029, YG 1041, YG 1042. Both studied samples were mutagenic for almost all tested strains, with the exception of the August sample which did not influence the strain TA 100 without the metabolic activation with the S9 fraction. The December sample exhibited higher genotoxic activity than the August sample. Mutagenicity ratios of the strains with reduced nitroreductase and O-acetyltransferase activities were higher, and of the strain without the nitroreductase--lower than those of the parent strains. This indicates that nitro and amino derivatives of PAHs are responsible for the significant proportion of total mutagenicity of the studied samples of particulates. Metabolic activation with the S9 fraction caused the increase of the mutagenic activity of the samples, which indicates the presence of promutagens. The GC-MS analysis revealed the presence of known indirect mutagens from the PAHs group.

  10. Microparticles containing propolis and metronidazole: in vitro characterization, release study and antimicrobial activity against periodontal pathogens.

    PubMed

    de Souza Ferreira, Sabrina Barbosa; de Assis Dias, Bruno Rafael; Obregón, Clarissa Silva; Gomes, Carla Carolina; de Araújo Pereira, Raphaela Regina; Ribeiro Godoy, Janine Silva; Estivalet Svidzinski, Terezinha Inez; Bruschi, Marcos Luciano

    2014-03-01

    Ethylcellulose microparticles containing metronidazole and propolis extractive solution were prepared and evaluated in vitro against periodontal pathogens. Scanning electron microscopy, particle size analysis, drug entrapment efficiency and drug release of microparticles were determined. The antimicrobial activity of microparticles was evaluated against microorganisms of periodontal importance (Enterococcus faecalis, Streptococcus pyogenes, Streptococcus mutans, Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli). It was obtained particles with regular morphology, mean diameter of 1.23 µm, and entrapment efficiency for propolis and metronidazole were 91.41% and 22.23%, respectively. In vitro release studies of propolis and metronidazole from microparticles showed prolonged drug release and controlled by Fickian diffusion. Both propolis and metronidazole displayed activity against the tested strains. Moreover, the results showed that the strains of E. faecalis, S. pyogenes and S. mutans were more susceptible to the propolis and E. faecalis to the metronidazole. It was also observed that the amount of metronidazole to inhibit the microorganism strains in the physical mixture with propolis was smaller than in the metronidazole alone, suggesting potentiation effect between propolis and metronidazole. These microparticles would be useful for developing intermediary or eventual dosage form to be administered into the periodontal pocket more easily and safely.

  11. Cytogenetic study of metronidazole and three metronidazole analogues in cultured human lymphocytes with and without metabolic activation.

    PubMed

    Gómez-Arroyo, Sandra; Melchor-Castro, Sara; Villalobos-Pietrini, Rafael; Camargo, Estela Meléndez; Salgado-Zamora, Héctor; Campos Aldrete, Maria Elena

    2004-06-01

    Metronidazole (MTZ) and other nitroimidazole derivatives have been extensively used to treat infections caused by protozoa and anaerobic bacteria. However, the need for new derivatives with similar therapeutic activity but lower toxicity to human beings prevails. On this purpose, three metronidazole analogues were synthesized, namely: 1-(p-methylphenacyl)-2-methyl-4-nitro imidazole (CPMe), 1-(p-methoxyphenacyl)-2-methyl-4-nitroimidazole (CPMeO), and 1-(p-fluorphenacyl)-2-methyl-4-nitroimidazole (CPF), which at low concentrations (0.5-2 microg/ml) showed a higher activity against Entamoeba histolytica than MTZ (3-6 microg/ml). The aim of this work was to investigate the cytogenetic effect of the three MTZ analogues on human lymphocyte cultures with and without metabolic activation in vitro, using the sister chromatid exchange test (SCE), comparatively with MTZ. The effect of the compounds on the cell proliferation kinetics (CPK) measured by the replication index (RI) and the cytotoxic effect in the mitotic index (MI) was evaluated as well. The SCE frequencies with and without S9 metabolic activation in treated and control lymphocytes showed no significant statistical differences. However when metabolic activation was involved a significant increase in the amount of third division metaphases provoked the CPK increased significantly with all the tested compounds. The RI showed similar behaviour, except for compound CPF.

  12. Trichomonas vaginalis: metronidazole and other nitroimidazole drugs are reduced by the flavin enzyme thioredoxin reductase and disrupt the cellular redox system. Implications for nitroimidazole toxicity and resistance.

    PubMed

    Leitsch, David; Kolarich, Daniel; Binder, Marina; Stadlmann, Johannes; Altmann, Friedrich; Duchêne, Michael

    2009-04-01

    Infections with the microaerophilic parasite Trichomonas vaginalis are treated with the 5-nitroimidazole drug metronidazole, which is also in use against Entamoeba histolytica, Giardia intestinalis and microaerophilic/anaerobic bacteria. Here we report that in T. vaginalis the flavin enzyme thioredoxin reductase displays nitroreductase activity with nitroimidazoles, including metronidazole, and with the nitrofuran drug furazolidone. Reactive metabolites of metronidazole and other nitroimidazoles form covalent adducts with several proteins that are known or assumed to be associated with thioredoxin-mediated redox regulation, including thioredoxin reductase itself, ribonucleotide reductase, thioredoxin peroxidase and cytosolic malate dehydrogenase. Disulphide reducing activity of thioredoxin reductase was greatly diminished in extracts of metronidazole-treated cells and intracellular non-protein thiol levels were sharply decreased. We generated a highly metronidazole-resistant cell line that displayed only minimal thioredoxin reductase activity, not due to diminished expression of the enzyme but due to the lack of its FAD cofactor. Reduction of free flavins, readily observed in metronidazole-susceptible cells, was also absent in the resistant cells. On the other hand, iron-depleted T. vaginalis cells, expressing only minimal amounts of PFOR and hydrogenosomal malate dehydrogenase, remained fully susceptible to metronidazole. Thus, taken together, our data suggest a flavin-based mechanism of metronidazole activation and thereby challenge the current model of hydrogenosomal activation of nitroimidazole drugs.

  13. Evaluation of Nitrofurantoin Combination Therapy of Metronidazole-Sensitive and -Resistant Helicobacter pylori Infections in Mice

    PubMed Central

    Jenks, Peter J.; Ferrero, Richard L.; Tankovic, Jacques; Thiberge, Jean-Michel; Labigne, Agnès

    2000-01-01

    The main objectives of this study were to determine whether the nitroreductase enzyme encoded by the rdxA gene of Helicobacter pylori was responsible for reductive activation of nitrofurantoin and whether a triple-therapy regimen with nitrofurantoin was able to eradicate metronidazole-sensitive and -resistant H. pylori infections from mice. The susceptibilities to nitrofurantoin of parent and isogenic rdxA mutant strains (three pairs), as well as a series of matched metronidazole-sensitive and -resistant strains isolated from mice (30) and patients (20), were assessed by agar dilution determination of the MIC. Groups of mice colonized with the metronidazole-sensitive H. pylori SS1 strain or a metronidazole-resistant rdxA SS1 mutant were treated with either metronidazole or nitrofurantoin as part of a triple-therapy regimen. One month after the completion of treatment the mice were sacrificed and their stomachs were cultured for H. pylori. The nitrofurantoin MICs for all strains tested were between 0.5 and 4.0 μg/ml. There was no significant difference between the susceptibility to nitrofurantoin of the parental strains and those of respective rdxA mutants or between those of matched metronidazole-sensitive and -resistant H. pylori isolates. The regimen with metronidazole eradicated infection from all eight SS1-infected mice and from one of eight mice inoculated with the rdxA mutant (P ≤ 0.001). The regimen with nitrofurantoin failed to eradicate infection from any of the six SS1-infected mice (P ≤ 0.001) and cleared infection from one of seven mice inoculated with the rdxA mutant. These results demonstrate that, despite the good in vitro activity of nitrofurantoin against H. pylori and the lack of cross-resistance between metronidazole and nitrofurantoin, eradication regimens involving nitrofurantoin are unable to eradicate either metronidazole-sensitive or -resistant H. pylori infections from mice. PMID:10991835

  14. Synthesis and evaluation of sulfate conjugated metronidazole as a colon-specific prodrug of metronidazole.

    PubMed

    Kim, Hyunjeong; Lee, Yonghyun; Yoo, Hansun; Kim, Jihye; Kong, Hyesik; Yoon, Jeong-Hyun; Jung, Yunjin; Kim, Young Mi

    2012-04-01

    For an effort to improve therapeutic property of metronidazole (MTZ) which is a drug of choice for protozoal infections such as luminal amoebiasis, sulfate conjugated metronidazole (MTZS) was prepared and evaluated as a colon-specific prodrug of MTZ. The apparent partition coefficient of MTZ was greatly reduced by the sulfate conjugation. While (bio)chemically stable in the contents of the upper intestine, MTZS was rapidly cleaved to liberate MTZ on incubation with the cecal contents of rats. MTZ liberated from MTZS metabolized quickly at least partly by a microbial nitroreductase, suggesting the relevance of the metabolism to bioactivation of MTZ for antimicrobial action. Consistent with the hypothesis, MTZS elicited antibacterial activity in the cecal contents, which was as potent as free MTZ. The systemic absorption of MTZS was very low after oral administration of MTZS. In parallel with this, whereas MTZ disappeared mostly during the transit of the proximal small intestine, a substantial amount of MTZS remained in the small intestine, moving down to the large intestine where it metabolized rapidly. In addition to the efficient colonic delivery of MTZS, MTZS markedly reduced the systemic absorption of MTZ. Taken together, MTZS may be a potential colon-specific prodrug of MTZ which possesses improved therapeutic and toxicological properties.

  15. A comparative study of metronidazole and sulfasalazine for active Crohn's disease: the cooperative Crohn's disease study in Sweden. II. Result.

    PubMed

    Ursing, B; Alm, T; Bárány, F; Bergelin, I; Ganrot-Norlin, K; Hoevels, J; Huitfeldt, B; Järnerot, G; Krause, U; Krook, A; Lindström, B; Nordle, O; Rosén, A

    1982-09-01

    Seventy-eight patients with active Crohn's disease participated in a randomized, double-blind, cross-over trial. The study comprised two 4-mo period. The purpose was to test the efficacy of metronidazole in comparison with that of sulfasalazine. As the main evaluation criteria the Crohn's Disease Activity Index and plasma levels of orosomucoid were chosen. In the first period no difference in efficacy as measured by Crohn's Disease Activity Index was found between the treatment groups. The reduction of the plasma orosomucoid level was significantly more pronounced in the metronidazole group. The hemoglobin concentration increased more in this group than in the sulfasalazine group, possibly due to a toxic effect of sulfasalazine. The erythrocyte sedimentation rate decreased similarly with both drugs. In 15 patients who had active disease throughout the first period, Crohn's Disease Activity Index decreased significantly in the second period for those who switched to metronidazole, but not for those who switched to sulfasalazine. After crossover, no apparent further change in Crohn's Disease Activity Index occurred in either of the treatment groups among patients who had responded favorably in the first period. The plasma concentration of orosomucoid increased significantly among the patients in the sulfasalazine group but not in the metronidazole group. It is therefore concluded that metronidazole is slightly more effective than sulfasalazine in the treatment of crohn's disease. It is worthwhile switching the drug regimen from sulfasalazine, when it fails, to metronidazole, but not from metronidazole to sulfasalazine.

  16. Synergic activity, for anaerobes, of trovafloxacin with clindamycin or metronidazole: chequerboard and time-kill methods.

    PubMed

    Ednie, L M; Credito, K L; Khantipong, M; Jacobs, M R; Appelbaum, P C

    2000-05-01

    Chequerboard titrations were used to test the activity of trovafloxacin, alone and in combination with clindamycin or metronidazole, against 156 Gram-positive or Gram-negative anaerobes, including 47 Bacteroides fragilis group, 36 Prevotella spp., 26 fusobacteria, 21 peptostreptococci and 26 clostridia. MIC50/MIC90 values (mg/L) of each drug alone against all 156 strains were: trovafloxacin, 0.5/1; clindamycin, 0.25/2; metronidazole, 1/2. Synergy (FIC indices metronidazole. All other combinations were additive (FIC indices >0. 5-2.0); no antagonism (FIC indices >4.0) was seen. In addition, synergy was tested by time-kill methodology for each of the above combinations against 12 Gram-positive or Gram-negative strains. Results indicated that synergy (defined as a >/= 2 log(10) decrease in cfu/mL at 48 h compared with the more active drug alone) was found between trovafloxacin at or below the MIC and both clindamycin and metronidazole at or below the MIC in one strain each of Bacteroides fragilis, Bacteroides thetaiotaomicron, Prevotella intermedia, Fusobacterium varium, Peptostreptococcus asaccharolyticus and Clostridium bifermentans. Synergy between trovafloxacin (metronidazole alone was seen in one strain each of Bacteroides distasonis, Prevotella bivia, Fusobacterium mortiferum, P. asaccharolyticus and C. bifermentans. In many cases of synergy, including those at the trovafloxacin MIC, regrowth after 48 h, which was commonly seen with trovafloxacin alone, was inhibited, and 99.9% killing was observed with the combination after 48 h, but not with trovafloxacin alone.

  17. Highly sensitive umu test system for the detection of mutagenic nitroarenes in Salmonella typhimurium NM3009 having high O-acetyltransferase and nitroreductase activities

    SciTech Connect

    Oda, Yoshimitsu; Yamazaki, Hiroshi; Watanabe, Masahiko; Nohmi, Takehiko; Shimada, Tsutomu )

    1993-01-01

    A highly sensitive umu test system for the detection of genotoxic activities of a variety of mutagenic nitroarenes has been developed using a new tester strain, Salmonella typhimurium NM3009 having high O-acetyltransferase (O-AT) and nitroreductase (NR) activities. The NM3009 was constructed by subcloning both the O-AT and NR genes into plasmid vector pACYC184, and the resulting plasmid was introduced into the parent tester strain S. typhimurium TA1535/pSK1002 harboring an umuC[prime]-[prime]lacZ fusion gene. The induction of umuC gene expression could be monitored by measuring the cellular [beta]-galactosidase activity produced by fusion gene. The purpose of the study was to evaluate whether the newly developed strain NM3009 is highly sensitive toward nitroarene compounds. The sensitivity of the strain NM3009 was compared with those of the parent TA1535/pSK1002 strain, the NR-overexpressing strain NM1011, the NR-deficient strain NM1000, the O-AT-overexpressing strain NM2009, and the O-AT-defective strain NM2000. The newly developed NM3009 strain had about 13-fold and 3-fold higher activities for N-AT and NR, respectively, than the original S. typhimurium TA1535/pSK1002 strain. Among six strains tested, NM3009 showed the highest sensitivity toward such chemicals as 1-nitronaphthalene, 2-nitrofluorene, 3,7-dinitro-fluoranthene, 3-nitrofluoranthene, 5-nitroacenaphthene, 2-nitronaphthalene, 1-nitropyrene, 1,6-dinitropyrene, 3,9-dinitrofluoranthene, 4,4[prime]-dinitrobiphenyl, 1,8-dinitropyrene, m-dinitrobenzene, 2,4-dinitrotoluene, and 1,3-dinitropyrene. The authors have also found that the order of sensitivities to induce umuC gene expression toward a variety of nitroarenes was NM3009 > NM2009 > NM1011 > TA1535/pSK1002 > NM2000 > NM1000. 40 refs., 3 figs., 3 tabs.

  18. Metronidazole lacks activity against Mycobacterium tuberculosis in an in vivo hypoxic granuloma model of latency

    PubMed Central

    Klinkenberg, Lee G.; Sutherland, Lesley A.; Bishai, William R.; Karakousis, Petros C.

    2009-01-01

    During human latent tuberculosis (TB) infection, dormant bacilli putatively reside within the hypoxic environment of caseating lung granulomas. The anaerobic drug metronidazole has antituberculous activity under hypoxic conditions in vitro, but lacks activity against murine TB. In this study, we used the hypoxia marker pimonidazole to demonstrate the presence of tissue hypoxia in a novel in vivo granuloma model of M. tuberculosis latency. We also used a high-throughput, microarray-based technique to identify hypoxia-essential mycobacterial genes, and showed that this in vivo model correctly identified 51% of hypoxia-attenuated mutants, a significantly larger percentage than that identified by the mouse (29%) and guinea pig (29%) aerosol models of TB. Although isoniazid showed activity during the first 28 days of therapy, and rifampin was active against dormant bacilli after the establishment of tissue hypoxia, metronidazole showed no antituberculous activity in this in vivo hypoxic granuloma model of M. tuberculosis dormancy. PMID:18491971

  19. Metronidazole Oral

    MedlinePlus

    Metronidazole eliminates bacteria and other microorganisms that cause infections of the reproductive system, gastrointestinal tract, skin, vagina, ... Metronidazole comes as a tablet to take by mouth. It is usually taken two or three times ...

  20. Synthesis and QSAR study of novel anti-inflammatory active mesalazine-metronidazole conjugates.

    PubMed

    Naumov, Roman N; Panda, Siva S; Girgis, Adel S; George, Riham F; Farhat, Michel; Katritzky, Alan R

    2015-06-01

    Novel, mesalazine, metronidazole conjugates 6a-e with amino acid linkers were synthesized utilizing benzotriazole chemistry. Biological data acquired for all the novel bis-conjugates showed (a) some bis-conjugates exhibit comparable anti-inflammatory activity with parent drugs and (b) the potent bis-conjugates show no visible stomach lesions. 3D-pharmacophore and 2D-QSAR modeling support the observed bio-properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Enhanced cell-specific ablation in zebrafish using a triple mutant of Escherichia coli nitroreductase.

    PubMed

    Mathias, Jonathan R; Zhang, Zhanying; Saxena, Meera T; Mumm, Jeff S

    2014-04-01

    Transgenic expression of bacterial nitroreductase (NTR) facilitates chemically-inducible targeted cell ablation. In zebrafish, the NTR system enables studies of cell function and cellular regeneration. Metronidazole (MTZ) has become the most commonly used prodrug substrate for eliciting cell loss in NTR-expressing transgenic zebrafish due to the cell-specific nature of its cytotoxic derivatives. Unfortunately, MTZ treatments required for effective cell ablation border toxic effects, and, thus, likely incur undesirable nonspecific effects. Here, we tested whether a triple mutant variant of NTR, previously shown to display improved activity in bacterial assays, can solve this issue by promoting cell ablation in zebrafish using reduced prodrug treatment regimens. We generated several complementary transgenic zebrafish lines expressing either wild-type or mutant NTR (mutNTR) in specific neural cell types, and assayed prodrug-induced cell ablation kinetics using confocal time series imaging and plate reader-based quantification of fluorescent reporters expressed in targeted cell types. The results show that cell ablation can be achieved in mutNTR expressing transgenic lines with markedly shortened prodrug exposure times and/or at lower prodrug concentrations. The mutNTR variant characterized here can circumvent problematic nonspecific/toxic effects arising from low prodrug conversion efficiency, thus increasing the effectiveness and versatility of this selective cell ablation methodology.

  2. Pharmacokinetics and serum bactericidal activities of quinolones in combination with clindamycin, metronidazole, and ornidazole.

    PubMed Central

    Boeckh, M; Lode, H; Deppermann, K M; Grineisen, S; Shokry, F; Held, R; Wernicke, K; Koeppe, P; Wagner, J; Krasemann, C

    1990-01-01

    To enhance the antimicrobial spectrum of the quinolones against anaerobic organisms and gram-positive bacteria, we investigated in two studies the parenteral combinations of ciprofloxacin (200 mg) and ofloxacin (200 mg) with metronidazole (500 mg) or clindamycin (600 mg) and the oral combinations of enoxacin (400 mg) and fleroxacin (400 mg) with metronidazole (400 mg), clindamycin (300 mg), or ornidazole (500 mg) (only with fleroxacin). The pharmacokinetics and serum bactericidal activities (SBAs) against 5 aerobic and 2 anaerobic species (total, 58 strains) were determined in two groups of 10 healthy volunteers by using a randomized crossover study design. The additions of metronidazole, clindamycin, and ornidazole did not affect the pharmacokinetics of the quinolones. The combination of clindamycin with ciprofloxacin, ofloxacin, and, to a lesser extent, fleroxacin resulted in an increase of the SBA against gram-positive strains (mean peak titers): Staphylococcus aureus, ciprofloxacin alone, 1:5.5; ciprofloxacin-clindamycin, 1:19.9; ofloxacin alone, 1:3.6; ofloxacin-clindamycin, 1:17.5; fleroxacin alone, 1:4.3; fleroxacin-clindamycin, 1:8.1; Streptococcus pneumoniae (fleroxacin and enoxacin were not tested), ciprofloxacin alone, 1:2.0; ciprofloxacin-clindamycin, 1:53; ofloxacin alone, 1:2.6; and ofloxacin-clindamycin, 1:49.2. The high SBA of quinolones against gram-negative bacteria was not affected by the combinations; however, relatively low activities against Pseudomonas aeruginosa were detected. In general, against anaerobic bacteria, low bactericidal activities were determined in both studies (mean peak titers ranged from 1:2.1 to 1:3.1; mean trough titers range from 1:2.0 to 1:2.9). In clinical settings with severe mixed infections, a parenteral therapy consisting of modern quinolones together with clindamycin or imidazole derivatives seems to be active and offers no obvious interactions. PMID:2088195

  3. Genotoxic effects of metronidazole.

    PubMed

    Elizondo, G; Gonsebatt, M E; Salazar, A M; Lares, I; Santiago, P; Herrera, J; Hong, E; Ostrosky-Wegman, P

    1996-09-13

    Metronidazole (MTZ) is an effective agent used in the treatment of parasitic infections. Its genotoxic effects have been shown in a variety of prokaryotic systems; however, negative results have been reported in human in vivo studies. Due to its wide spread use, a study was performed to evaluate the chromosomal aberration frequencies in peripheral blood lymphocyte cultures from 10 individuals, before and after metronidazole treatment. A significant increase in the percentage of cells with chromatid and isochromatid breaks was observed after metronidazole treatment (1500 mg per day for 10 days). The percentages of cells with aberrations did not correlate with the levels of MTZ found in plasma. Individual variability was observed with respect to both the induction of aberrations and the concentration of MTZ in plasma. They could represent differences at the metabolic level, since metronidazole is known to be biotransformed by a polymorphic P450 cytochrome, and its metabolites have shown mutagenic activity.

  4. In vitro activity of nitazoxanide against some metronidazole-resistant and susceptible Trichomonas vaginalis isolates.

    PubMed

    Abdel-Magied, Aida A; Hammouda, Marwa M; Mosbah, Alaa; El-Henawy, Abeer A

    2017-04-01

    Trichomonas vaginalis cases refractory to metronidazole (MTZ) treatment had been reported. This study aimed to the assessment of in vitro metronidazole resistance among Trichomonas positive cases with treatment failure by determination of metronidazole minimal lethal concentration (MLC), and to the evaluation of the in vitro efficacy of nitazoxanide (NTZ) as compared to metronidazole (MTZ) in both resistant and susceptible isolates. Drug testing was carried out by an aerobic tube assay where suspension of Trichomonas trophozoites was exposed for 24 and 48 h to serial dilution of metronidazole and nitazoxanide. In refractory isolates n = 30, median MLC conc. for MTZ was 100 μg/ml versus 50 μg/ml for NTZ (P < .0001). After 48 h median MLC conc. for MTZ was 25 μg/ml versus 12 μg/ml for NTZ (P < .0001). NTZ against resistant isolates was twice as active as MTZ at 24 h and increased to 2.5 times at 48 h while in susceptible isolates, NTZ was twice as active as MTZ at both 24 h and 48 h. MTZ was about 8 times more active in susceptible than in resistant isolates. So, high doses of metronidazole in resistant cases will likely increase side effects. The study proved the activity of NTZ against trichomoniasis especially in cases with MTZ resistance. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  5. Evaluation of antitumor activity and development of solid lipid nanoparticles of metronidazole analogue.

    PubMed

    Lages, Eduardo Burgarelli; de Freitas, Maria Betânia; Gonçalves, Isadora Marques Brum; Alves, Ricardo José; Vianna-Soares, Cristina Duarte; Ferreira, Lucas Antônio Miranda; de Oliveira, Mônica Cristina; de Oliveira, Renata Barbosa

    2013-11-01

    Nitroheterocyclic compounds have received considerable interest as hypoxia-selective cytotoxins (HSC) for cancer treatment. In the present study, we investigated antitumor activity of an iodide analogue of metronidazole, 1-(2-iodoethyl)-2-methyl-5-nitroimidazole (MTZ-I), using Swiss mice bearing solid Ehrlich tumor. MTZ-I showed potent anti-cancer activity at a dose of 40 mg/kg. MTZ-I loaded solid lipid nanoparticles (SLN) were developed as an alternative colloidal carrier system to enhance tumor drug uptake. SLN were characterized for particle size, polydispersity index, zeta potential and entrapment efficiency. In addition, the influence of presence of the cationic lipid stearylamine (STE) on stability of formulation was assessed. The results of DSC study showed that MTZ-I exhibited interaction with STE.

  6. Metronidazole Topical

    MedlinePlus

    ... a moisturizer (if your skin is dry) and cosmetics. Ask your doctor for advice on what cosmetics to use.Metronidazole gel for the vagina comes ... not swallow it. Do not apply dressings, bandages, cosmetics, lotions, or other skin medications to the area ...

  7. Combined antitumor activity of the nitroreductase/CB1954 suicide gene system and γ-rays in HeLa cells in vitro

    PubMed Central

    Teng, Geling; Ju, Yuanrong; Yang, Yepeng; Hua, Hu; Chi, Jingyu; Mu, Xiuan

    2016-01-01

    Escherichia coli nitroreductase (NTR) may convert the prodrug CB1954 (5-(aziridin-1-yl)-2,4-dinitrobenzamide) into a bifunctional alkylating agent, which may lead to DNA crosslinks and the apoptosis of cancer cells. NTR/CB1954 has been demonstrated to be an effective gene therapy in cancer cells. The present study examined whether the NTR/CB1954 suicide gene system had cytotoxic effects on HeLa cells and may improve the radiosensitivity of HeLa cells to γ-rays. It was observed that the NTR/CB1954 suicide gene system exerted marked cytotoxic effects on HeLa cells. The combined therapeutic effects of NTR/CB1954 and γ-rays on HeLa cells demonstrated a synergistic effect. CB1954 at concentrations of 12.5 and 25 µmol/l increased the sensitization enhancement ratio of HeLa cells to 1.54 and 1.66, respectively. Therefore, when compared with monotherapy, the combined therapy of NTR/CB1954 and γ-rays may increase the apoptotic rate and enhance the radiosensitivity of HeLa cells. The combined therapy of γ-ray radiation and the NTR/CB1954 suicide gene system may be a novel and potent therapeutic method for the treatment of cervical carcinoma. PMID:27840931

  8. Combined antitumor activity of the nitroreductase/CB1954 suicide gene system and γ-rays in HeLa cells in vitro.

    PubMed

    Teng, Geling; Ju, Yuanrong; Yang, Yepeng; Hua, Hu; Chi, Jingyu; Mu, Xiuan

    2016-12-01

    Escherichia coli nitroreductase (NTR) may convert the prodrug CB1954 (5-(aziridin-1-yl)-2,4-dinitrobenzamide) into a bifunctional alkylating agent, which may lead to DNA crosslinks and the apoptosis of cancer cells. NTR/CB1954 has been demonstrated to be an effective gene therapy in cancer cells. The present study examined whether the NTR/CB1954 suicide gene system had cytotoxic effects on HeLa cells and may improve the radiosensitivity of HeLa cells to γ‑rays. It was observed that the NTR/CB1954 suicide gene system exerted marked cytotoxic effects on HeLa cells. The combined therapeutic effects of NTR/CB1954 and γ‑rays on HeLa cells demonstrated a synergistic effect. CB1954 at concentrations of 12.5 and 25 µmol/l increased the sensitization enhancement ratio of HeLa cells to 1.54 and 1.66, respectively. Therefore, when compared with monotherapy, the combined therapy of NTR/CB1954 and γ‑rays may increase the apoptotic rate and enhance the radiosensitivity of HeLa cells. The combined therapy of γ‑ray radiation and the NTR/CB1954 suicide gene system may be a novel and potent therapeutic method for the treatment of cervical carcinoma.

  9. Anti-anaerobic activity of levofloxacin alone and combined with clindamycin and metronidazole.

    PubMed

    Credito, K L; Jacobs, M R; Appelbaum, P C

    2000-11-01

    Microdilution MICs of levofloxacin against twelve anaerobes ranged between 0.5-8.0 microg/ml and those of clindamycin and metronidazole between 0.008-2.0 and 0.25->16.0 microg/ml, respectively. Combination of levofloxacin with clindamycin and/or metronidazole in time-kill tests led to synergy at levofloxacin concentrations at or below the MIC in 7/12 strains.

  10. Megazol and its bioisostere 4H-1,2,4-triazole: comparing the trypanocidal, cytotoxic and genotoxic activities and their in vitro and in silico interactions with the Trypanosoma brucei nitroreductase enzyme

    PubMed Central

    de Carvalho, Alcione Silva; Salomão, Kelly; de Castro, Solange Lisboa; Conde, Taline Ramos; Zamith, Helena Pereira da Silva; Caffarena, Ernesto Raúl; Hall, Belinda Suzette; Wilkinson, Shane Robert; Boechat, Núbia

    2014-01-01

    Megazol (7) is a 5-nitroimidazole that is highly active against Trypanosoma cruzi and Trypanosoma brucei, as well as drug-resistant forms of trypanosomiasis. Compound 7 is not used clinically due to its mutagenic and genotoxic properties, but has been largely used as a lead compound. Here, we compared the activity of 7 with its 4H-1,2,4-triazole bioisostere (8) in bloodstream forms of T. brucei and T. cruzi and evaluated their activation by T. brucei type I nitroreductase (TbNTR) enzyme. We also analysed the cytotoxic and genotoxic effects of these compounds in whole human blood using Comet and fluorescein diacetate/ethidium bromide assays. Although the only difference between 7 and 8 is the substitution of sulphur (in the thiadiazole in 7) for nitrogen (in the triazole in 8), the results indicated that 8 had poorer antiparasitic activity than 7 and was not genotoxic, whereas 7 presented this effect. The determination of Vmax indicated that although 8 was metabolised more rapidly than 7, it bounds to the TbNTR with better affinity, resulting in equivalent kcat/KM values. Docking assays of 7 and 8 performed within the active site of a homology model of the TbNTR indicating that 8 had greater affinity than 7. PMID:24676659

  11. Metronidazole. A therapeutic review and update.

    PubMed

    Freeman, C D; Klutman, N E; Lamp, K C

    1997-11-01

    The nitroimidazole antibiotic metronidazole has a limited spectrum of activity that encompasses various protozoans and most Gram-negative and Gram-positive anaerobic bacteria. Metronidazole has activity against protozoans like Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis, for which the drug was first approved as an effective treatment. Anaerobic bacteria which are typically sensitive are primarily Gram-negative anaerobes belonging to the Bacteroides and Fusobacterium spp. Gram-positive anaerobes such as peptostreptococci and Clostridia spp. are likely to test sensitive to metronidazole, but resistant isolates are probably encountered with greater frequency than with the Gram-negative anaerobes. Gardnerella vaginalis is a pleomorphic Gram-variable bacterial bacillus that is also susceptible to metronidazole. Helicobacter pylori has been strongly associated with gastritis and duodenal ulcers. Classic regimens for eradicating this pathogen have included metronidazole, usually with acid suppression medication plus bismuth and amoxicillin. The activity of metronidazole against anaerobic bowel flora has been used for prophylaxis and treatment of patients with Crohn's disease who might develop an infectious complication. Treatment of Clostridium difficile-induced pseudomembraneous colitis has usually been with oral metronidazole or vancomycin, but the lower cost and similar efficacy of metronidazole, coupled with the increased concern about imprudent use of vancomycin leading to increased resistance in enterococci, have made metronidazole the preferred agent here. Metronidazole has played an important role in anaerobic-related infections. Advantages to using metronidazole are the percentage of sensitive Gram-negative anaerobes, its availability as oral and intravenous dosage forms, its rapid bacterial killing, its good tissue penetration, its considerably lower chance of inducing C. difficile colitis, and expense. Metronidazole has notable

  12. The underappreciated in vitro activity of tedizolid against Bacteroides fragilis species, including strains resistant to metronidazole and carbapenems.

    PubMed

    Goldstein, Ellie J C; Citron, Diane M; Tyrrell, Kerin L; Leoncio, Elisa S; Merriam, C Vreni

    2017-02-01

    Because Bacteroides fragilis has the ability to develop mechanisms of resistance to almost all antibiotics, we studied the comparative in vitro activity of tedizolid against 124 Bacteroides group species clinical isolates, including carbapenem, metronidazole and piperacillin-tazobactam resistant strains. Tedizolid had an MIC90 of 2 μg/ml (range, 0.5-4 μg/ml) and was 1-4 times more active than linezolid that had an MIC90 of 8 μg/ml (range, 2-16 μg/ml). It was also active (MICs 0.5-2 μg/ml) against the 27 ertapenem, 2 metronidazole and 12 piperacillin-tazobactam resistant strains tested. This suggests that tedizolid may be useful treating infections, including bacteremias, due to resistant B. fragilis group species, as well as, mixed skin and soft tissue infections such as diabetic foot infections caused by Gram-positive aerobes and B. fragilis group species. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Quinone- and nitroreductase reactions of Thermotoga maritima peroxiredoxin-nitroreductase hybrid enzyme.

    PubMed

    Anusevičius, Žilvinas; Misevičienė, Lina; Šarlauskas, Jonas; Rouhier, Nicolas; Jacquot, Jean-Pierre; Čėnas, Narimantas

    2012-12-01

    Thermotoga maritima peroxiredoxin-nitroreductase hybrid enzyme (Prx-NR) consists of a FMN-containing nitroreductase (NR) domain fused to a peroxiredoxin (Prx) domain. These domains seem to function independently as no electron transfer occurs between them. The reduction of quinones and nitroaromatics by NR proceeded in a two-electron manner, and follows a 'ping-pong' scheme with sometimes pronounced inhibition by quinone substrate. The comparison of steady- and presteady-state kinetic data shows that in most cases, the oxidative half-reaction may be rate-limiting in the catalytic cycle of NR. The enzyme was inhibited by dicumarol, a classical inhibitor of oxygen-insensitive nitroreductases. The reduction of quinones and nitroaromatic compounds by Prx-NR was characterized by the linear dependence of their reactivity (logk(cat)/K(m)) on their single-electron reduction potentials E(7)(1), while the reactivity of quinones markedly exceeded the one with nitroaromatics. It shows that NR lacks the specificity for the particular structure of these oxidants, except their single-electron accepting potency and the rate of electron self-exchange. It points to the possibility of a single-electron transfer step in a net two-electron reduction of quinones and nitroaromatics by T. maritima Prx-NR, and to a significant diversity of the structures of flavoenzymes which may perform the two-electron reduction of quinones and nitroaromatics.

  14. Bismuth, Metronidazole, and Tetracycline

    MedlinePlus

    Helidac® (as a kit containing Bismuth Subsalicylate, Metronidazole, Tetracycline) ... Bismuth, metronidazole, and tetracycline is used along with other ulcer medications to treat duodenal ulcers. It is in a ...

  15. Metronidazole (Flagyl) and Pregnancy

    MedlinePlus

    Metronidazole (Flagyl®) In every pregnancy, a woman starts out with a 3-5% chance of having a ... risk. This sheet talks about whether exposure to metronidazole may increase the risk for birth defects over ...

  16. Metronidazole (Flagyl) and Pregnancy

    MedlinePlus

    ... than 40 years, and is sold under the brand name Flagyl®. Can taking metronidazole during early pregnancy ... previously raised some concerns. Older studies suggested an association between metronidazole and an increase in various birth ...

  17. Identification of novel nitroreductases from Bacillus cereus and their interaction with the CB1954 prodrug.

    PubMed

    Gwenin, Vanessa V; Poornima, Paramasivan; Halliwell, Jennifer; Ball, Patrick; Robinson, George; Gwenin, Chris D

    2015-12-01

    Directed enzyme prodrug therapy is a form of cancer chemotherapy in which bacterial prodrug-activating enzymes, or their encoding genes, are directed to the tumour before administration of a prodrug. The prodrug can then be activated into a toxic drug at the tumour site, reducing off-target effects. The bacterial nitroreductases are a class of enzymes used in this therapeutic approach and although very promising, the low turnover rate of prodrug by the most studied nitroreductase enzyme, NfnB from Escherichia coli (NfnB_Ec), is a major limit to this technology. There is a continual search for enzymes with greater efficiency, and as part of the search for more efficient bacterial nitroreductase enzymes, two novel enzymes from Bacillus cereus (strain ATCC 14579) have been identified and shown to reduce the CB1954 (5-(aziridin-1-yl)-2,4-dinitrobenzamide) prodrug to its respective 2'-and 4'-hydroxylamine products. Both enzymes shared features characteristic of the nitro-FMN-reductase superfamily including non-covalently associated FMN, requirement for the NAD(P)H cofactor, homodimeric, could be inhibited by Dicoumarol (3,3'-methylenebis(4-hydroxy-2H-chromen-2-one)), and displayed ping pong bi bi kinetics. Based on the biochemical characteristics and nucleotide alignment with other nitroreductase enzymes, one enzyme was named YdgI_Bc and the other YfkO_Bc. Both B. cereus enzymes had greater turnover for the CB1954 prodrug compared with NfnB_Ec, and in the presence of added NADPH cofactor, YfkO_Bc had superior cell killing ability, and produced mainly the 4'-hydroxylamine product at low prodrug concentration. The YfkO_Bc was identified as a promising candidate for future enzyme prodrug therapy.

  18. Overall adsorption rate of metronidazole, dimetridazole and diatrizoate on activated carbons prepared from coffee residues and almond shells.

    PubMed

    Flores-Cano, J V; Sánchez-Polo, M; Messoud, J; Velo-Gala, I; Ocampo-Pérez, R; Rivera-Utrilla, J

    2016-03-15

    This study analyzed the overall adsorption rate of metronidazole, dimetridazole, and diatrizoate on activated carbons prepared from coffee residues and almond shells. It was also elucidated whether the overall adsorption rate was controlled by reaction on the adsorbent surface or by intraparticle diffusion. Experimental data of the pollutant concentration decay curves as a function of contact time were interpreted by kinetics (first- and second-order) and diffusion models, considering external mass transfer, surface and/or pore volume diffusion, and adsorption on an active site. The experimental data were better interpreted by a first-order than second-order kinetic model, and the first-order adsorption rate constant varied linearly with respect to the surface area and total pore volume of the adsorbents. According to the diffusion model, the overall adsorption rate is governed by intraparticle diffusion, and surface diffusion is the main mechanism controlling the intraparticle diffusion, representing >90% of total intraparticle diffusion.

  19. Purification and characterization of NAD(P)H-dependent nitroreductase I from Klebsiella sp. C1 and enzymatic transformation of 2,4,6-trinitrotoluene.

    PubMed

    Kim, Hyoun-Young; Song, Hong-Gyu

    2005-10-01

    Three NAD(P)H-dependent nitroreductases that can transform 2,4,6-trinitrotoluene (TNT) by two reduction pathways were detected in Klebsiella sp. C1. Among these enzymes, the protein with the highest reduction activity of TNT (nitroreductase I) was purified to homogeneity using ion-exchange, hydrophobic interaction, and size exclusion chromatographies. Nitroreductase I has a molecular mass of 27 kDa as determined by SDS-PAGE, and exhibits a broad pH optimum between 5.5 and 6.5, with a temperature optimum of 30-40 degrees C. Flavin mononucleotide is most likely the natural flavin cofactor of this enzyme. The N-terminal amino acid sequence of this enzyme does not show a high degree of sequence similarity with nitroreductases from other enteric bacteria. This enzyme catalyzed the two-electron reduction of several nitroaromatic compounds with very high specific activities of NADPH oxidation. In the enzymatic transformation of TNT, 2-amino-4,6-dinitrotoluene and 2,2',6,6'-tetranitro-4,4'-azoxytoluene were detected as transformation products. Although this bacterium utilizes the direct ring reduction and subsequent denitration pathway together with a nitro group reduction pathway, metabolites in direct ring reduction of TNT could not easily be detected. Unlike other nitroreductases, nitroreductase I was able to transform hydroxylaminodinitrotoluenes (HADNT) into aminodinitrotoluenes (ADNT), and could reduce ortho isomers (2-HADNT and 2-ADNT) more easily than their para isomers (4-HADNT and 4-ADNT). Only the nitro group in the ortho position of 2,4-DNT was reduced to produce 2-hydroxylamino-4-nitrotoluene by nitroreductase I; the nitro group in the para position was not reduced.

  20. Comparison of the in vitro activities of fenticonazole, other imidazoles, metronidazole, and tetracycline against organisms associated with bacterial vaginosis and skin infections.

    PubMed Central

    Jones, B M; Geary, I; Lee, M E; Duerden, B I

    1989-01-01

    The in vitro antibacterial activity of the antifungal compound fenticonazole was compared with those of clotrimazole, miconazole, tetracycline, and metronidazole against 177 strains of bacterial species associated with either bacterial vaginosis (BV) or skin infections by agar dilution MIC determinations. BV-associated Bacteroides isolates of the Bacteroides melaninogenicus-B. oralis group, Gardnerella vaginalis, Mobiluncus spp., and anaerobic, gram-positive cocci were highly susceptible to fenticonazole, clotrimazole, and miconazole; but Bacteroides spp. not associated with BV, Bacteroides ureolyticus and the Bacteroides fragilis group, were resistant. All Bacteroides strains were susceptible to metronidazole, but the susceptibility of G. vaginalis and Mobiluncus spp. varied. Among the skin bacteria, Staphylococcus aureus, coryneforms, and streptococci were highly susceptible to the imidazoles; but Staphylococcus epidermidis strains were generally resistant. This antibacterial activity may give fenticonazole a useful role in the topical treatment of vaginal discharge and in mycotic skin infections that are superinfected with bacteria. PMID:2764547

  1. Proteomic Analysis of a NAP1 Clostridium difficile Clinical Isolate Resistant to Metronidazole

    PubMed Central

    Chong, Patrick M.; Lynch, Tarah; McCorrister, Stuart; Kibsey, Pamela; Miller, Mark; Gravel, Denise; Westmacott, Garrett R.; Mulvey, Michael R.

    2014-01-01

    Background Clostridium difficile is an anaerobic, Gram-positive bacterium that has been implicated as the leading cause of antibiotic-associated diarrhea. Metronidazole is currently the first-line treatment for mild to moderate C. difficile infections. Our laboratory isolated a strain of C. difficile with a stable resistance phenotype to metronidazole. A shotgun proteomics approach was used to compare differences in the proteomes of metronidazole-resistant and -susceptible isolates. Methodology/Principal Findings NAP1 C. difficile strains CD26A54_R (Met-resistant), CD26A54_S (reduced- susceptibility), and VLOO13 (Met-susceptible) were grown to mid-log phase, and spiked with metronidazole at concentrations 2 doubling dilutions below the MIC. Peptides from each sample were labeled with iTRAQ and subjected to 2D-LC-MS/MS analysis. In the absence of metronidazole, higher expression was observed of some proteins in C. difficile strains CD26A54_S and CD26A54_R that may be involved with reduced susceptibility or resistance to metronidazole, including DNA repair proteins, putative nitroreductases, and the ferric uptake regulator (Fur). After treatment with metronidazole, moderate increases were seen in the expression of stress-related proteins in all strains. A moderate increase was also observed in the expression of the DNA repair protein RecA in CD26A54_R. Conclusions/Significance This study provided an in-depth proteomic analysis of a stable, metronidazole-resistant C. difficile isolate. The results suggested that a multi-factorial response may be associated with high level metronidazole-resistance in C. difficile, including the possible roles of altered iron metabolism and/or DNA repair. PMID:24400070

  2. Proteomic analysis of a NAP1 Clostridium difficile clinical isolate resistant to metronidazole.

    PubMed

    Chong, Patrick M; Lynch, Tarah; McCorrister, Stuart; Kibsey, Pamela; Miller, Mark; Gravel, Denise; Westmacott, Garrett R; Mulvey, Michael R

    2014-01-01

    Clostridium difficile is an anaerobic, Gram-positive bacterium that has been implicated as the leading cause of antibiotic-associated diarrhea. Metronidazole is currently the first-line treatment for mild to moderate C. difficile infections. Our laboratory isolated a strain of C. difficile with a stable resistance phenotype to metronidazole. A shotgun proteomics approach was used to compare differences in the proteomes of metronidazole-resistant and -susceptible isolates. NAP1 C. difficile strains CD26A54_R (Met-resistant), CD26A54_S (reduced- susceptibility), and VLOO13 (Met-susceptible) were grown to mid-log phase, and spiked with metronidazole at concentrations 2 doubling dilutions below the MIC. Peptides from each sample were labeled with iTRAQ and subjected to 2D-LC-MS/MS analysis. In the absence of metronidazole, higher expression was observed of some proteins in C. difficile strains CD26A54_S and CD26A54_R that may be involved with reduced susceptibility or resistance to metronidazole, including DNA repair proteins, putative nitroreductases, and the ferric uptake regulator (Fur). After treatment with metronidazole, moderate increases were seen in the expression of stress-related proteins in all strains. A moderate increase was also observed in the expression of the DNA repair protein RecA in CD26A54_R. This study provided an in-depth proteomic analysis of a stable, metronidazole-resistant C. difficile isolate. The results suggested that a multi-factorial response may be associated with high level metronidazole-resistance in C. difficile, including the possible roles of altered iron metabolism and/or DNA repair.

  3. Synthesis, characterization and antimicrobial activity of water-soluble silver(i) complexes of metronidazole drug and selected counter-ions.

    PubMed

    Kalinowska-Lis, Urszula; Felczak, Aleksandra; Chęcińska, Lilianna; Zawadzka, Katarzyna; Patyna, Emilia; Lisowska, Katarzyna; Ochocki, Justyn

    2015-05-07

    A series of water-soluble silver(i) complexes of the type [Ag(MTZ)2X] [MTZ = 1-(2-hydroxyethyl)-2-methyl-5-nitro-1H-imidazole (metronidazole drug); X = NO3(-), ClO4(-), CF3COO(-), BF4(-) and CH3SO3(-)] was synthesised by the reactions of various Ag(i) salts with metronidazole (MTZ). All the complexes were characterized by ESI-MS spectrometry, solution NMR ((1)H and (13)C) and IR spectroscopy, and elemental analysis. Further evidence for the formation and molecular structure of all the complexes was provided by X-ray single-crystal crystallography. The different counter ions affect the crystal packing of the complexes and thus have an impact on the final geometries. The antimicrobial activities of the complexes against two Gram-positive strains: Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, three Gram-negative strains: Pseudomonas aeruginosa ATCC 15442, Escherichia coli ATCC 25922, Proteus hauseri ATCC 13315 and yeast Candida albicans ATCC 10231 were evaluated and compared with antibacterial and antifungal properties of appropriate silver salts, metronidazole and silver sulfadiazine drugs. The newly synthesized compounds exhibited significant antibacterial activity against Gram-positive bacteria, better than the referenced silver sulfadiazine. The best active silver(i)-metronidazole complex contains a methanesulphonate counter-ion. Moreover, the complex inhibited the growth of yeast Candida albicans at a concentration 3-fold lower than that required for silver sulfadiazine. In addition, the complexes containing a tetrafluoroborate and a perchlorate as counter-ions were characterized as effective antibacterial agents against the tested Gram-negative bacteria.

  4. Targeted ablation of beta cells in the embryonic zebrafish pancreas using E.coli nitroreductase

    PubMed Central

    Pisharath, Harshan; Rhee, Jerry M.; Swanson, Michelle A.; Leach, Steven D.; Parsons, Michael J.

    2007-01-01

    In order to generate a zebrafish model of β cell regeneration, we have expressed an E.coli gene called nfsB in the β cells of embryonic zebrafish. This bacterial gene encodes a nitroreductase (NTR) enzyme, which can convert prodrugs such as metronidazole (Met) to cytotoxins. By fusing nfsB to mCherry, we can simultaneously render β cells susceptible to prodrug and visualize Met dependent cell ablation. We show that the neighboring α and δ cells are unaffected by prodrug treatment and that ablation is β cell specific. Following drug removal and 36hrs of recovery, β cells regenerate. Using ptf1a morphants, it is clear that this β cell recovery occurs independently of the presence of the exocrine pancreas. Also, by using photoconvertible Kaede to cell lineage trace and BrdU incorporation to label proliferation, we investigate mechanisms for β regeneration. Therefore, we have developed a unique resource for the study of β cell regeneration in a living vertebrate organism, which will provide the opportunity to conduct large-scale screens for pharmacological and genetic modifiers of β cell regeneration. PMID:17223324

  5. The NprA nitroreductase required for 2,4-dinitrophenol reduction in Rhodobacter capsulatus is a dihydropteridine reductase.

    PubMed

    Pérez-Reinado, Eva; Roldán, María Dolores; Castillo, Francisco; Moreno-Vivián, Conrado

    2008-11-01

    The Rhodobacter capsulatus nprA gene codes for a putative nitroreductase. A recombinant His(6)-NprA protein was overproduced in Escherichia coli and purified by affinity chromatography. This protein contained FMN and showed nitroreductase activity with a wide range of nitroaromatic compounds, such as 2-nitrophenol, 2,4-dinitrophenol, 2,6-dinitrophenol, 2,4,6-trinitrophenol (picric acid), 2,4-dinitrobenzoate and 2,4-dinitrotoluene, and with the nitrofuran derivatives nitrofurazone and furazolidone. NADPH was the main electron donor and the ortho nitro group was preferably reduced to the corresponding amino derivative. The apparent K(m) values of NprA for NADPH, 2,4-dinitrophenol, picric acid and furazolidone were 40 microM, 78 microM, 72 microM and 83 microM, respectively, at pH and temperature optima (pH 6.5, 30 degrees C). Escherichia coli cells overproducing the NprA protein were much more sensitive to the prodrug 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB1954) used in cancer therapy than non-transformed cells. NprA showed the highest activity with the quinonoid form of 6,7-dimethyl-7,8-dihydropterine as substrate, so that NprA may be involved in the synthesis of tetrahydrobiopterin in R. capsulatus. Expression of a transcriptional nprA-lacZ gene fusion was induced by phenylalanine or tyrosine, but not by other amino acids like glutamate or alanine. Furthermore, both nitroreductase activity and phenylalanine assimilation were inhibited in vivo by ammonium. A mutant defective in the nprA gene showed better growth rate with Phe or Tyr as nitrogen source than the wild-type strain, although both strains showed similar growth in media with Glu or without added nitrogen. These results suggest that the NprA nitroreductase may act in vivo as a dihydropteridine reductase involved in aromatic amino acids metabolism.

  6. The redox-active drug metronidazole and thiol-depleting garlic compounds act synergistically in the protist parasite Spironucleus vortens.

    PubMed

    Williams, C F; Vacca, A R; Dunham, L; Lloyd, D; Coogan, M P; Evans, G; Graz, M; Cable, J

    2016-01-01

    Spironucleus vortens is a protozoan parasite associated with significant mortalities in the freshwater angelfish, Pterophyllum scalare. Control of this parasite is especially problematic due to restrictions on the use of the drug of choice, metronidazole (MTZ), on fish farms. Use of garlic (Allium sativum) is undergoing a renaissance following experimental validations of its antimicrobial efficiency. Ajoene ((E,Z)-4,5,9-trithiadodeca-1,6,11-triene 9-oxide), is a stable transformation product of allicin, the primary biologically active component of garlic. In the current study, an ajoene oil crude extract had a minimum inhibitory concentration (MIC) of 40μg/ml against S. vortens. GC-MS and NMR spectroscopy revealed this ajoene extract contained a mixture of the (E) and (Z)-ajoene isomers along with diallyl disulphide (DADS) and diallyl trisulphide (DATS). The only component of the ajoene crude oil found to substantially inhibit S. vortens growth by optical density monitoring (Bioscreen C Reader) was (Z)-ajoene (MIC 16μg/ml). Ajoene oil acted in synergy with MTZ in vitro, reducing the individual MIC of this drug (4μg/ml) by 16-fold, and that of ajoene oil by 200-fold with a fractional inhibitory concentration (FIC) index of 0.263. This synergistic interaction was confirmed in vivo. S. vortens-infected Pterophyllum scalare angelfish dosed orally with 0.5% (v/w) MTZ combined with 0.05% (v/w) ajoene displayed a significant reduction in faecal trophozoite count, whilst those fed on 0.5% MTZ flakes (half the recommended oral dose) alone did not. This study demonstrates for the first time the synergistic interaction between the synthetic drug MTZ and natural ajoene oil both in vitro and in vivo. Future work should evaluate the potential synergy of ajoene and MTZ against MTZ-resistant bacteria and protists. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  7. PnrA, a new nitroreductase-family enzyme in the TNT-degrading strain Pseudomonas putida JLR11.

    PubMed

    Caballero, Antonio; Lázaro, Juan J; Ramos, Juan L; Esteve-Núñez, Abraham

    2005-08-01

    Nitroreductases are a group of proteins that catalyse pyridine nucleotide-dependent reduction of nitroaromatics compounds, showing significant human health and environmental implications. In this study we have identified the nitroreductase-family enzymes PnrA and PnrB from the TNT-degrading strain Pseudomonas putida. The enzyme encoded by the pnrA gene was expressed in Escherichia coli, purified to homogeneity and shown to be a flavoprotein that used 2 mol of NADPH to reduce 1 mol of 2,4,6-trinitrotoluene (TNT) to 4-hydroxylamine-2,6-dinitrotoluene, using a ping-pong bi-bi mechanism. The PnrA enzyme also recognized as substrates as a number of other nitroaromatic compounds, i.e. 2,4-dinitrotoluene, 3-nitrotoluene, 3- and 4-nitrobenzoate, 3,5-dinitrobenzamide and 3,5-dinitroaniline expanding the substrates profile from previously described nitroreductases. However, TNT resulted to be the most efficient substrate examined according to the Vmax/Km parameter. Expression analysis of pnrA- and pnrB-mRNA isolated from cells growing on different nitrogen sources suggested that expression of both genes was constitutive and that its level of expression was relatively constant regardless of the growth substrate. This is in agreement with enzyme-specific activity determined with cells growing with different N-sources.

  8. Chloramphenicol Is a Substrate for a Novel Nitroreductase Pathway in Haemophilus influenzae▿

    PubMed Central

    Smith, Arnold L.; Erwin, Alice L.; Kline, Toni; Unrath, William C. T.; Nelson, Kevin; Weber, Allan; Howald, William N.

    2007-01-01

    The p-nitroaromatic antibiotic chloramphenicol has been used extensively to treat life-threatening infections due to Haemophilus influenzae and Neisseria meningitidis; its mechanism of action is the inhibition of protein synthesis. We found that during incubation with H. influenzae cells and lysates, chloramphenicol is converted to a 4-aminophenyl allylic alcohol that lacks antibacterial activity. The allylic alcohol moiety undergoes facile re-addition of water to restore the 1,3-diol, as well as further dehydration driven by the aromatic amine to form the iminoquinone. Several Neisseria species and most chloramphenicol-susceptible Haemophilus species, but not Escherichia coli or other gram-negative or gram-positive bacteria we examined, were also found to metabolize chloramphenicol. The products of chloramphenicol metabolism by species other than H. influenzae have not yet been characterized. The strains reducing the antibiotic were chloramphenicol susceptible, indicating that the pathway does not appear to mediate chloramphenicol resistance. The role of this novel nitroreductase pathway in the physiology of H. influenzae and Neisseria species is unknown. Further understanding of the H. influenzae chloramphenicol reduction pathway will contribute to our knowledge of the diversity of prokaryotic nitroreductase mechanisms. PMID:17526758

  9. Identification of a type I nitroreductase gene in non-virulent Trypanosoma rangeli.

    PubMed

    Montenegro, Marjorie; Cuervo, Claudia; Cardenas, Constanza; Duarte, Silvia; Díaz, Jenny R; Thomas, M Carmen; Lopez, Manuel C; Puerta, Concepcion J

    2017-07-01

    Trypanosomatid type I nitroreductases (NTRs), i.e., mitochondrial enzymes that metabolise nitroaromatic pro-drugs, are essential for parasite growth, infection, and survival. Here, a type I NTR of non-virulent protozoan Trypanosoma rangeli is described and compared to those of other trypanosomatids. The NTR gene was isolated from KP1(+) and KP1(-) strains, and its corresponding transcript and 5' untranslated region (5'UTR) were determined. Bioinformatics analyses and nitro-drug activation assays were also performed. The results indicated that the type I NTR gene is present in both KP1(-) and KP1(+) strains, with 98% identity. However, the predicted subcellular localisation of the protein differed among the strains (predicted as mitochondrial in the KP1(+) strain). Comparisons of the domains and 3D structures of the NTRs with those of orthologs demonstrated that the nitroreductase domain of T. rangeli NTR is conserved across all the strains, including the residues involved in the interaction with the FMN cofactor and in the tertiary structure characteristics of this oxidoreductase protein family. mRNA processing and expression were also observed. In addition, T. rangeli was shown to be sensitive to benznidazole and nifurtimox in a concentration-dependent manner. In summary, T. rangeli appears to have a newly discovered functional type I NTR.

  10. Metronidazole and 5-aminosalicylic acid enhance the contractile activity of histaminergic agonists on the guinea-pig isolated ileum

    SciTech Connect

    Winbery, S.L.; Barker, L.A.

    1986-03-01

    The effects of metronidazole and 5-aminosalicylic acid (5-ASA) on histamine receptor-effector systems in the small intestine and right atrium of the guinea pig were studied. In an apparently all-or-none manner, both caused a sinistral shift in dose-response curves for the phasic component of the contractile response to histamine at H1 receptors on the ileum. In the presence of either, the EC50 value for histamine was reduced from 0.07 to about 0.03 microM. Similarly, in an apparently all-or-none fashion, both produced an elevation in the dose-response curve for the actions of dimaprit at H2-receptors in the ileum; the response to all doses was increased about 30% with no significant change in the EC50 value. Metronidazole and 5-ASA did not alter dose-response curves for the tonic contractile response to histamine or curves generated by the cumulative addition of histamine. Also, neither altered the positive chronotropic response on isolated right atria or the phasic contractile response on isolated segments of jejunum and duodenum to histamine or dimaprit. Likewise, neither altered dose-response curves for the direct action of carbamylcholine at muscarinic receptors or for the indirect actions of dimethylphenylpiperazinium on the ileum. The effects of 5-ASA or metronidazole on the response to histamine could be prevented as well as reversed by scopolamine or tetrodotoxin. The results suggest that metronidazole and 5-ASA enhance the actions of histamine and dimaprit on the ileum by an action on myenteric plexus neurons.

  11. The role of two putative nitroreductases, Frm2p and Hbn1p, in the oxidative stress response in Saccharomyces cerevisiae.

    PubMed

    de Oliveira, Iuri Marques; Zanotto-Filho, Alfeu; Moreira, José Cláudio Fonseca; Bonatto, Diego; Henriques, João Antonio Pêgas

    2010-02-01

    The nitroreductase family is comprised of a group of FMN- or FAD-dependent enzymes that are able to metabolize nitrosubstituted compounds using the reducing power of NAD(P)H. These nitroreductases can be found in bacterial species and, to a lesser extent, in eukaryotes. There is little information on the biochemical functions of nitroreductases. Some studies suggest their possible involvement in the oxidative stress response. In the yeast Saccharomyces cerevisiae, two nitroreductase proteins, Frm2p and Hbn1p, have been described. While Frm2p appears to act in the lipid signalling pathway, the function of Hbn1p is completely unknown. In order to elucidate the functions of Frm2p and Hbn1p, we evaluated the sensitivity of yeast strains, proficient and deficient in both oxidative stress proteins, for respiratory competence, antioxidant-enzyme activities, intracellular reactive oxygen species (ROS) production and lipid peroxidation. We found reduced basal activity of superoxide dismutase (SOD), ROS production, lipid peroxidation and petite induction and higher sensitivity to 4-nitroquinoline-oxide (4-NQO) and N-nitrosodiethylamine (NDEA), as well as higher basal activity of catalase (CAT) and glutathione peroxidase (GPx) and reduced glutathione (GSH) content in the single and double mutant strains frm2Delta and frm2Delta hbn1Delta. These strains exhibited less ROS accumulation and lipid peroxidation when exposed to peroxides, H(2)O(2) and t-BOOH. In summary, the Frm1p and Hbn1p nitroreductases influence the response to oxidative stress in S. cerevisae yeast by modulating the GSH contents and antioxidant enzymatic activities, such as SOD, CAT and GPx.

  12. Controlled synthesis of uniform BiVO4 microcolumns and advanced visible-light-driven photocatalytic activity for the degradation of metronidazole-contained wastewater.

    PubMed

    Yu, Chongfei; Dong, Shuying; Feng, Jinglan; Sun, Jingyu; Hu, Limin; Li, Yukun; Sun, Jianhui

    2014-02-01

    Well-defined, uniform bismuth vanadate (BiVO4) microcolumns were synthesized through a refined hydrothermal route. During the fabrication process, a detailed orthogonal design on the synthetic conditions was performed, aiming to optimize the experimental parameters to produce BiVO4 materials (BiVO4 (Opt.)) with the most prominent visible-light-driven photocatalytic efficiency, where the catalytic activities of the synthesized materials were evaluated via the decolorization of methylene blue under visible light irradiation. The BiVO4 (Opt.) were then targetedly produced according to the determined optimal conditions and well characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, ultraviolet and visible diffuse-reflectance spectroscopy and photoluminescence spectroscopy. Compared with the commercial P25-TiO2 photocatalysts, the as-synthesized BiVO4 (Opt.) displayed superior visible-light-driven photocatalytic activities for the degradation of metronidazole-contained wastewater with the presence of H2O2. The degradation efficiency of metronidazole reached up to 70 % within 180 min, leading to a brief speculation on the possibly major steps of the visible-light-driven photocatalytic process. The current study provides a distinctive route to design novel shaped BiVO4 architectures with advanced photocatalytic capacities for the treatment of organic pollutants in the aqueous environment.

  13. Mechanical and thermal studies of metronidazole crystals

    NASA Astrophysics Data System (ADS)

    Ramukutty, S.; Jeyasudha, R.; Ramachandran, E.

    2013-10-01

    Single crystals of metronidazole have been synthesized natural evaporation method. The grown crystal has been confirmed using single crystal X-ray diffraction analysis. Mechanical behavior has been determined using Vickers hardness measurement. Work-hardening coefficient and Newtonian resistance pressure of the crystal have been estimated. Kinetic analysis of the thermogravimetric data has been carried out by using Coats-Redfern relation. Activation energy, frequency factor and order of reaction have been also calculated. The Arrhenius equation for metronidazole is k = 0.38 × 108 e-76.679/ RT mol-1 s-1. Thermodynamic parameters have been also determined.

  14. Metabolism and metronidazole uptake in Trichomonas vaginalis isolates with different metronidazole susceptibilities.

    PubMed Central

    Müller, M; Gorrell, T E

    1983-01-01

    Three Trichomonas vaginalis isolates with low in vivo susceptibilities to metronidazole (95% curative dose, greater than 3 X 100 mg kg-1 in subcutaneous infections in mice) were compared with strain ATCC 30001 and with four isolates exhibiting high in vivo susceptibilities (95% curative dose, less than 3 X 15 mg kg-1). Activity of pyruvate:ferredoxin oxidoreductase, anaerobic fermentation, and anaerobic intracellular accumulation of [14C]metronidazole label showed no significant isolate-dependent differences which could be correlated with drug susceptibility. The results suggest that processes providing electrons for metronidazole activation are not defective in the resistant strains. Aerobiosis, known to inhibit the antimicrobial action of metronidazole, inhibited accumulation of label more strongly in resistant isolates than in susceptible ones. No differences were detected, however, between resistant and susceptible isolates in respiration, aerobic fermentation, and the specific activity of NADH and NADPH oxidases, the main terminal oxidases of T. vaginalis. These findings suggest that the production of electrons is not diminished under aerobic conditions. The inhibitory effect of aerobic conditions on metronidazole activation, possibly due to competition for the electrons, is markedly enhanced in the resistant isolates compared to the susceptible ones. The mechanism of this effect, however, remains unknown. PMID:6607028

  15. Efficacy of New 5-Nitroimidazoles against Metronidazole-Susceptible and -Resistant Giardia, Trichomonas, and Entamoeba spp.

    PubMed Central

    Upcroft, Jacqueline A.; Campbell, Raymond W.; Benakli, Kamel; Upcroft, Peter; Vanelle, Patrice

    1999-01-01

    The efficacies of 12 5-nitroimidazole compounds and 1 previously described lactam-substituted nitroimidazole with antiparasitic activity, synthesized via SRN1 and subsequent reactions, were assayed against the protozoan parasites Giardia duodenalis, Trichomonas vaginalis, and Entamoeba histolytica. Two metronidazole-sensitive lines and two metronidazole-resistant lines of Giardia and one line each of metronidazole-sensitive and -resistant Trichomonas were tested. All except one of the compounds were as effective or more effective than metronidazole against Giardia and Trichomonas, but none was as effective overall as the previously described 2-lactam-substituted 5-nitroimidazole. None of the compounds was markedly more effective than metronidazole against Entamoeba. Significant cross-resistance between most of the drugs tested and metronidazole was evident among metronidazole-resistant lines of Giardia and Trichomonas. However, some drugs were lethal to metronidazole-resistant Giardia and had minimum lethal concentrations similar to that of metronidazole for drug-susceptible parasites. This study emphasizes the potential in developing new nitroimidazole drugs which are more effective than metronidazole and which may prove to be useful clinical alternatives to metronidazole. PMID:9869568

  16. Method of controlled reduction of nitroaromatics by enzymatic reaction with oxygen sensitive nitroreductase enzymes

    DOEpatents

    Shah, Manish M.; Campbell, James A.

    1998-01-01

    A method for the controlled reduction of nitroaromatic compounds such as nitrobenzene and 2,4,6-trinitrotoluene by enzymatic reaction with oxygen sensitive nitroreductase enzymes, such as ferredoxin NADP oxidoreductase.

  17. Method of controlled reduction of nitroaromatics by enzymatic reaction with oxygen sensitive nitroreductase enzymes

    DOEpatents

    Shah, M.M.; Campbell, J.A.

    1998-07-07

    A method is described for the controlled reduction of nitroaromatic compounds such as nitrobenzene and 2,4,6-trinitrotoluene by enzymatic reaction with oxygen sensitive nitroreductase enzymes, such as ferredoxin NADP oxidoreductase. 6 figs.

  18. Response to Metronidazole and Oxidative Stress Is Mediated through Homeostatic Regulator HsrA (HP1043) in Helicobacter pylori

    PubMed Central

    Olekhnovich, Igor N.; Vitko, Serhiy; Valliere, Meaghan

    2014-01-01

    Metronidazole (MTZ) is often used in combination therapies to treat infections caused by the gastric pathogen Helicobacter pylori. Resistance to MTZ results from loss-of-function mutations in genes encoding RdxA and FrxA nitroreductases. MTZ-resistant strains, when cultured at sub-MICs of MTZ (5 to 20 μg/ml), show dose-dependent defects in bacterial growth; depressed activities of many Krebs cycle enzymes, including pyruvate:ferredoxin oxidoreductase (PFOR); and low transcript levels of porGDAB (primer extension), phenotypes consistent with an involvement of a transcriptional regulator. Using a combination of protein purification steps, electrophoretic mobility shift assays (EMSAs), and mass spectrometry analyses of proteins bound to porG promoter sequences, we identified HP1043, an essential homeostatic global regulator (HsrA [for homeostatic stress regulator]). Competition EMSAs and supershift analyses with HsrA-enriched protein fractions confirmed specific binding to porGDAB and hsrA promoter sequences. Exposure to MTZ resulted in >10-fold decreases in levels of HsrA and in levels of the HsrA-regulated gene products PFOR and TlpB. Exposure to paraquat (PQ), hydrogen peroxide, or organic peroxides showed near equivalence with MTZ, revealing a common oxidative stress response pathway. Finally, direct superoxide dismutase (SOD) assays showed an inverse relationship between HsrA levels and SOD activity, suggesting that HsrA may serve as a repressor of sodB. As a homeostatic sentinel, HsrA appears to be ideally positioned to enable rapid shutdown of genes associated with metabolism and growth while activating (directly or indirectly) oxidative defense genes in response to low levels of toxic metabolites (MTZ or oxygen) before they reach DNA-damaging levels. PMID:24296668

  19. The effects of metronidazole on Cytochrome P450 Activity and Expression in rats after acute exposure to high altitude of 4300m.

    PubMed

    Wang, Rong; Sun, Yuhuan; Yin, Qiang; Xie, Hua; Li, Wenbin; Wang, Chang; Guo, Jiankui; Hao, Ying; Tao, Rui; Jia, Zhengping

    2017-01-01

    The purpose is to observe the changes of CYP450 enzyme activity expression as well as the physiological and pathological states of Wistar rats given metronidazole drug intervention after acute exposure to high altitude of 4300m. Thirty healthy adult male Wistar rats of average weight 200 ± 20 g were randomly assigned into three groups of 10 rats per group as follows: Group A (55m), Group B (4300m) and Group C (metronidazole intervention, 4300m). After three days, the main blood gas levels were detected and the liver tissue pathological slices were observed. The enzymatic activity of CYP1A2 and 3A1 as well as the total protein, total CYP450, cytochrome b5 and the protein expression of CYP450 isoforms CYP1A2 and 3A1 were detected. Compared with Group A and Group B, the expression of total CYP450 and CYP1A2 was significantly reduced (P<0.01or P<0.05), the enzymatic activity of CYP1A2 and CYP3A1 were significantly reduced (P<0.05, P<0.01), respectively and CYP3A1 had no significant changes (P>0.05). Compared with Group B and Group C the enzymatic activity of CYP1A2 had no significant changes (P>0.050), the enzymatic activity of CYP3A1 was significantly reduced (P<0.01). The total cytochrome p450, CYP1A2 and cytochrome b5 were significantly reduced (P<0.01 and P<0.05), respectively and CYP3A1 had no significant changes (P>0.05). Pathological observation showed that rats in Group A were normal with no significant pathological changes in their livers; rats in Group B suffered from liver injuries and edema with a few of them caught inflammatory cell infiltration; rats in Group C caught liver cell edema, inflammatory diseases and lobular vena cava expansion. Acute exposure to high altitude CYP450 isoform expression and the enzymatic activity were significantly reduced, both the physiology and pathology of rats were substantially impaired, and which maybe resulted from the hypoxia and drug intervention interrelated effected in plateau filed test. Copyright © 2016

  20. Delamanid is not metabolized by Salmonella or human nitroreductases: A possible mechanism for the lack of mutagenicity.

    PubMed

    Hanaki, Erina; Hayashi, Mikayo; Matsumoto, Makoto

    2017-03-01

    Nitro-containing compounds such as nitrofuran and nitroimidazole are drugs used for the treatment of infectious diseases. However, many of these nitro-containing drugs are positive in the bacterial reverse mutation assay (Ames test). The recently approved anti-multidrug-resistant tuberculosis (MDR-TB) drug, delamanid (Deltyba™; OPC-67683), a derivative of 4-nitroimidazole, was negative for mutagenicity in the Ames assay. In Salmonella typhimurium, mutagenicity of nitro compounds has been closely associated with the ability of nitroreductase to metabolize (degradation)these compounds. To explore the lack of mutagenicity for delamanid, we examined the initial metabolic rate and mutagenic-specific activity of a series of nitro compounds in S. typhimurium TA100. The order of maximum mutagenic-activity was nitrofuran > 2-nitroimidazole > 5-nitroimidazole ≥ 4-nitroimidazole, which is very similar to the order of initial metabolic rate, i.e., the Pearson's correlation coefficient (r = 0.85) showed a correlation between metabolic rate and mutagenic-activity. No metabolism of delamanid was detected even after 60 h of treatment. In addition, delamanid was not reduced by two human nitroreductases. These facts may explain the absence of genotoxicity of delamanid in both in vitro and in vivo tests.

  1. Crystal Structure of Reduced MsAcg, a Putative Nitroreductase from Mycobacterium smegmatis and a Close Homologue of Mycobacterium tuberculosis Acg

    PubMed Central

    Chauviac, François-Xavier; Bommer, Martin; Yan, Jun; Parkin, Gary; Daviter, Tina; Lowden, Philip; Raven, Emma L.; Thalassinos, Konstantinos; Keep, Nicholas H.

    2012-01-01

    This paper presents the structure of MsAcg (MSMEG_5246), a Mycobacterium smegmatis homologue of Mycobacterium tuberculosis Acg (Rv2032) in its reduced form at 1.6 Å resolution using x-ray crystallography. Rv2032 is one of the most induced genes under the hypoxic model of tuberculosis dormancy. The Acg family turns out to be unusual flavin mononucleotide (FMN)-binding proteins that have probably arisen by gene duplication and fusion from a classical homodimeric nitroreductase such that the monomeric protein resembles a classical nitroreductase dimer but with one active site deleted and the other active site covered by a unique lid. The FMN cofactor is not reduced by either NADH or NADPH, but the chemically reduced enzyme is capable of reduction of nitro substrates, albeit at no kinetic advantage over free FMN. The reduced enzyme is rapidly oxidized by oxygen but without any evidence for a radical state commonly seen in oxygen-sensitive nitroreductases. The presence of the unique lid domain, the lack of reduction by NAD(P)H, and the slow rate of reaction of the chemically reduced protein raises a possible alternative function of Acg proteins in FMN storage or sequestration from other biochemical pathways as part of the bacteria's adaptation to a dormancy state. PMID:23148223

  2. Biochemical characterization of NfsA, the Escherichia coli major nitroreductase exhibiting a high amino acid sequence homology to Frp, a Vibrio harveyi flavin oxidoreductase.

    PubMed Central

    Zenno, S; Koike, H; Kumar, A N; Jayaraman, R; Tanokura, M; Saigo, K

    1996-01-01

    We identified the nfsA gene, encoding the major oxygen-insensitive nitroreductase in Escherichia coli, and determined its position on the E. coli map to be 19 min. We also purified its gene product, NfsA, to homogeneity. It was suggested that NfsA is a nonglobular protein with a molecular weight of 26,799 and is associated tightly with a flavin mononucleotide. Its amino acid sequence is highly similar to that of Frp, a flavin oxidoreductase from Vibrio harveyi (B. Lei, M. Liu, S. Huang, and S.-C. Tu, J. Bacteriol. 176:3552-3558, 1994), an observation supporting the notion that E. coli nitroreductase and luminescent-bacterium flavin reductase families are intimately related in evolution. Although no appreciable sequence similarity was detected between two E. coli nitroreductases, NfsA and NfsB, NfsA exhibited a low level of the flavin reductase activity and a broad electron acceptor specificity similar to those of NfsB. NfsA reduced nitrofurazone by a ping-pong Bi-Bi mechanism possibly to generate a two-electron transfer product. PMID:8755878

  3. Successful treatment of refractory Trichomonas vaginalis infection using intravenous metronidazole.

    PubMed

    Hawkins, Isobel; Carne, Christopher; Sonnex, Christopher; Carmichael, Andrew

    2015-08-01

    Trichomonas vaginalis is a sexually transmitted protozoan infection resulting in a vulvo-vaginitis and altered vaginal discharge in symptomatic women. Since its introduction in the 1960 s, metronidazole has been the first-line drug for trichomonal infection. Other nitroimidazoles, such as tinidazole, are used as alternative regimens with similar activity but at a greater expense. Treatment failure usually represents patient non-compliance or reinfection, although metronidazole resistance has previously been documented. Sensitivity testing is currently not available in the UK. Patients with disease unresponsive to first-line treatments pose a major challenge, as therapeutic options are limited. This case looks at a patient with refractory disease over an 18-month period, where intravenous infusion of metronidazole resulted in cure after multiple previous therapy failures. There is limited evidence to endorse the use of intravenous metronidazole, and this case report provides further support for its efficacy. © The Author(s) 2014.

  4. Metronidazole-Induced Cerebellar Toxicity

    PubMed Central

    Agarwal, Amit; Kanekar, Sangam; Sabat, Shyam; Thamburaj, Krishnamurthy

    2016-01-01

    Metronidazole is a very common antibacterial and antiprotozoal with wide usage across the globe, including the least developed countries. It is generally well-tolerated with a low incidence of serious side-effects. Neurological toxicity is fairly common with this drug, however majority of these are peripheral neuropathy with very few cases of central nervous toxicity reported. We report the imaging findings in two patients with cerebellar dysfunction after Metronidazole usage. Signal changes in the dentate and red nucleus were seen on magnetic resonance imaging in these patients. Most of the cases reported in literature reported similar findings, suggesting high predilection for the dentate nucleus in metronidazole induced encephalopathy. PMID:27127600

  5. Reduction of quinones and nitroaromatic compounds by Escherichia coli nitroreductase A (NfsA): Characterization of kinetics and substrate specificity.

    PubMed

    Valiauga, Benjaminas; Williams, Elsie M; Ackerley, David F; Čėnas, Narimantas

    2017-01-15

    NfsA, a major FMN-associated nitroreductase of E. coli, reduces nitroaromatic compounds via consecutive two-electron transfers. NfsA has potential applications in the biodegradation of nitroaromatic environment pollutants, e.g. explosives, and is also of interest for the anticancer strategy gene-directed enzyme prodrug therapy. However, the catalytic mechanism of NfsA is poorly characterized. Here we examined the NADPH-dependent reduction of quinones (n = 16) and nitroaromatic compounds (n = 12) by NfsA. We confirmed a general "ping-pong" reaction scheme, and preliminary rapid reaction studies of the enzyme reduction by NADPH showed that this step is much faster than the steady-state turnover number, i.e., the enzyme turnover is limited by the oxidative half-reaction. The reactivity of nitroaromatic compounds (log kcat/Km) followed a linear dependence on their single-electron reduction potential (E(1)7), indicating a limited role for compound structure or active site flexibility in their reactivity. The reactivity of quinones was lower than that of nitroaromatics having similar E(1)7 values, except for the significantly enhanced reactivity of 2-OH-1,4-naphthoquinones, consistent with observations previously made for the group B nitroreductase of Enterobacter cloacae. We present evidence that the reduction of quinones by NfsA is most consistent with a single-step (H(-)) hydride transfer mechanism.

  6. Indirect electroreduction as pretreatment to enhance biodegradability of metronidazole.

    PubMed

    Saidi, I; Soutrel, I; Floner, D; Fourcade, F; Bellakhal, N; Amrane, A; Geneste, F

    2014-08-15

    The removal of metronidazole, a biorecalcitrant antibiotic, by coupling an electrochemical reduction with a biological treatment was examined. Electroreduction was performed in a home-made flow cell at -1.2V/SCE on graphite felt. After only one pass through the cell, analysis of the electrolyzed solution showed a total degradation of metronidazole. The biodegradability estimated from the BOD5/COD ratio increased from 0.07 to 0.2, namely below the value usually considered as the limit of biodegradability (0.4). In order to improve these results, indirect electrolysis of metronidazole was performed with a titanium complex known to reduce selectively nitro compounds into amine. The catalytic activity of the titanium complex towards electroreduction of metronidazole was shown by cyclic voltammetry analyses. Indirect electrolysis led to an improvement of the biodegradability from 0.07 to 0.42. To confirm the interest of indirect electroreduction to improve the electrochemical pretreatment, biological treatment was then carried out on activated sludge after direct and indirect electrolyses; different parameters were followed during the culture such as pH, TOC and metronidazole concentration. Both electrochemical processes led to a more efficient biodegradation of metronidazole compared with the single biological treatment, leading to an overall mineralization yield for the coupling process of 85%. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Metronidazole neurotoxicosis in two cats.

    PubMed

    Caylor, K B; Cassimatis, M K

    2001-01-01

    Two cats were presented for neurological dysfunction from suspected metronidazole toxicity. One cat was receiving 111 mg/kg body weight per day of metronidazole for 9 weeks. After 9 weeks, the dose was increased to 222 mg/kg body weight per day, and 2 days later the cat began to experience progressive neurological signs that culminated in generalized seizures. The second cat was receiving metronidazole at a total dose of 58 mg/kg body weight per day for 6 months. This cat experienced acute onset of ataxia and alteration in mentation. Laboratory evaluations in both cases were without significant findings. The neurological signs in both cats resolved within days of initiating supportive therapy and withdrawal of the drug. This report describes the two cases and discusses the etiology of metronidazole neurotoxicosis.

  8. Absence of Strand Breaks in Deoxyribonucleic Acid Treated with Metronidazole

    PubMed Central

    LaRusso, Nicholas F.; Tomasz, Maria; Kaplan, David; Müller, Miklós

    1978-01-01

    The deoxyribonucleic acid (DNA)-degrading potential of metronidazole was evaluated in vitro by three techniques: determination of melting curve, measurement of viscosity, and centrifugation in neutral or alkaline sucrose gradients. Studies were performed on calf thymus DNA and on 3H-labeled or unlabeled pneumococcal and T7 phage DNA after treatment with metronidazole alone or metronidazole reduced by sodium dithionite in the presence of DNA. This latter process is known to elicit covalent binding of metronidazole to DNA. Reduced or unreduced metronidazole had no effect on the melting properties, viscosity, or sedimentation velocity of the nucleic acids studied. Sodium dithionite alone, however, caused a 25% decrease in the intrinsic viscosity of pneumococcal DNA, and decreased the sedimentation velocity of pneumococcal and T7 phage DNA in both neutral and alkaline sucrose gradients. These data suggest that degradation of DNA is not important in the interaction of metronidazole with nucleic acids, an interaction assumed relevant to the cytotoxic, radiosensitizing, and mutagenic activities of this compound. PMID:626487

  9. A comparative study of metronidazole and sulfasalazine for active Crohn's disease: the cooperative Crohn's disease study in Sweden. I. Design and methodologic considerations.

    PubMed

    Rosén, A; Ursing, B; Alm, T; Bárány, F; Bergelin, I; Ganrot-Norlin, K; Hoevels, J; Huitfeldt, B; Järnerot, G; Krause, U; Krook, A; Lindström, B; Nordle, O

    1982-09-01

    The design and execution of the Cooperative Crohn's Disease Study in Sweden are described in this paper. A double-blind, double-dummy, crossover (2 X 4 mo) technique was used to compare the suppressive efficacy of metronidazole (0.4 g b.i.d.) and sulfasalazine (1.5 g b.i.d.). The number of randomized patients (78) presented approximately one-third of the available population. The Crohn's Disease Activity Index and the plasma level of orosomucoid were the main variables for clinical evaluation. Results were analyzed primarily in the first treatment period by ranking the clinical outcome of every patient according to a uniform and detailed scheme and applying Wilcoxon nonparametric statistics. The cross-over data only served as additional information. Thirty-six patients had had earlier and mostly positive experience with sulfasalazine. Repeated plasma drug analysis indicated good compliance. The blindness of the trial was tested and appeared satisfactory. The coordination of the trial proceeded as planned. A lack of full conformity in the electroimmunoassay of orosomucoid was taken care of satisfactorily.

  10. Surface orientation control of site-specifically immobilized nitro-reductase (NfsB).

    PubMed

    Shen, Lei; Schroeder, McKenna; Ogorzalek, Tadeusz L; Yang, Pei; Wu, Fu-Gen; Marsh, E Neil G; Chen, Zhan

    2014-05-27

    We demonstrate the control of enzyme orientation for enzymes chemically immobilized on surfaces. Nitro-reductase (NfsB) has the ability to reduce a broad range of nitro-containing compounds and has potential applications in a broad range of areas including the detection and decomposition of explosives. The enzyme was tethered through unique surface cysteine residues to a self-assembled monolayer (SAM) terminated with maleimide groups. One cysteine was introduced close to the active site (V424C), and the other, at a remote site (H360C). The surface-tethered NfsB variants were interrogated by a combination of surface-sensitive sum frequency generation (SFG) vibrational spectroscopy and attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) to determine how the mode of attachment altered the enzyme's orientation. The activities of the two immobilized NfsB variants were measured and can be well correlated to the deduced orientations. The relationships among enzyme engineering, surface immobilization, enzyme orientation, and enzyme activity were revealed.

  11. Structural and Mechanistic Insights into the Pseudomonas fluorescens 2-Nitrobenzoate 2-Nitroreductase NbaA

    PubMed Central

    Song, Wooseok; Kim, Jin-Sik; Jiao, Li; Lee, Kangseok

    2015-01-01

    The bacterial 2-nitroreductase NbaA is the primary enzyme initiating the degradation of 2-nitrobenzoate (2-NBA), and its activity is controlled by posttranslational modifications. To date, the structure of NbaA remains to be elucidated. In this study, the crystal structure of a Cys194Ala NbaA mutant was determined to a 1.7-Å resolution. The substrate analog 2-NBA methyl ester was used to decipher the substrate binding site by inhibition of the wild-type NbaA protein. Tandem mass spectrometry showed that 2-NBA methyl ester produced a 2-NBA ester bond at the Tyr193 residue in the wild-type NbaA but not residues in the Tyr193Phe mutant. Moreover, covalent binding of the 2-NBA methyl ester to Tyr193 reduced the reactivity of the Cys194 residue on the peptide link. The Tyr193 hydroxyl group was shown to be essential for enzyme catalysis, as a Tyr193Phe mutant resulted in fast dissociation of flavin mononucleotide (FMN) from the protein with the reduced reactivity of Cys194. FMN binding to NbaA varied with solution NaCl concentration, which was related to the catalytic activity but not to cysteine reactivity. These observations suggest that the Cys194 reactivity is negatively affected by a posttranslational modification of the adjacent Tyr193 residue, which interacts with FMN and the substrate in the NbaA catalytic site. PMID:26025888

  12. Optimization of Metronidazole Emulgel

    PubMed Central

    Rao, Monica; Sukre, Girish; Aghav, Sheetal; Kumar, Manmeet

    2013-01-01

    The purpose of the present study was to develop and optimize the emulgel system for MTZ (Metronidazole), a poorly water soluble drug. The pseudoternary phase diagrams were developed for various microemulsion formulations composed of Capmul 908 P, Acconon MC8-2, and propylene glycol. The emulgel was optimized using a three-factor, two-level factorial design, the independent variables selected were Capmul 908 P, and surfactant mixture (Acconon MC8-2 and gelling agent), and the dependent variables (responses) were a cumulative amount of drug permeated across the dialysis membrane in 24 h (Y 1) and spreadability (Y 2). Mathematical equations and response surface plots were used to relate the dependent and independent variables. The regression equations were generated for responses Y 1 and Y 2. The statistical validity of the polynomials was established, and optimized formulation factors were selected. Validation of the optimization study with 3 confirmatory runs indicated a high degree of prognostic ability of response surface methodology. Emulgel system of MTZ was developed and optimized using 23 factorial design and could provide an effective treatment against topical infections. PMID:26555982

  13. Drug repurposing strategy against Trypanosoma cruzi infection: in vitro and in vivo assessment of the activity of metronidazole in mono- and combined therapy.

    PubMed

    Simões-Silva, M R; De Araújo, J S; Oliveira, G M; Demarque, K C; Peres, R B; D'Almeida-Melo, I; Batista, D G J; Da Silva, C F; Cardoso-Santos, C; Da Silva, P B; Batista, M M; Bahia, M T; Soeiro, M N C

    2017-09-01

    Metronidazole (Mtz) is a commercial broad-spectrum nitroimidazolic derivative with relevant antimicrobial activity and relative safety profile. Therefore, it is fair to consider Mtz a candidate for drug repurposing for other neglected conditions such as Chagas disease (CD), a parasitic pathology caused by Trypanosoma cruzi. CD is treated only with benznidazole (Bz) and nifurtimox, both introduced in clinics decades ago despite important limitations, including low efficacy on the later disease stage (chronic form) and severe side effects. New cheap and fast alternative treatments for CD are needed, thus the repurposing of Mtz was assessed in vitro and in vivo in mono- and combined therapy. In vitro assays demonstrated EC50 > 200 µM for Mtz, while for Bz the values ranged from 2.51 µM (intracellular forms) to 11.5 µM (bloodstream trypomastigotes). When both drugs were combined in fixed-ratio proportions, Mtz promoted Bz potency (lower EC50 values). In vivo toxicity assays for Mtz in mice showed no adverse effects neither histopathological alterations up to 2000 mg/kg. Regarding experimental T.cruzi infection, Bz 100 mg/kg suppressed parasitemia while Mtz (up to 1000 mg/kg) in monotherapy did not, but prolonged animal survival at 250 and 500 regimen doses. The combination of both drugs (Bz 10 + Mtz 250) prevented mortality (70%) besides protected against electric cardiac alterations triggered by the parasite infection. Although not able to reduce parasite load, the combination therapy prevented animal mortality; this was possibly due to a protection of the electric cardiac physiology that is normally altered in experimental infection of T. cruzi. It also suggested that the interaction with Mtz could have improved the pharmacokinetics of Bz. Our study emphasizes the importance of drug repurposing and combined therapy for CD to contribute to alternative therapies for this neglected and silent pathology. Copyright © 2017. Published by Elsevier Inc.

  14. Metronidazole hydrazone conjugates: Design, synthesis, antiamoebic and molecular docking studies.

    PubMed

    Ansari, Mohammad Fawad; Siddiqui, Shadab Miyan; Agarwal, Subhash M; Vikramdeo, Kunwar Somesh; Mondal, Neelima; Azam, Amir

    2015-09-01

    Metronidazole hydrazone conjugates (2-13) were synthesized and screened in vitro for antiamoebic activity against HM1: IMSS strain of Entamoeba histolytica. Six compounds were found to be better inhibitors of E. histolytica than the reference drug metronidazole. These compounds showed greater than 50-60% viability against HeLa cervical cancer cell line after 72 h treatment. Also, molecular docking study was undertaken on E. histolytica thioredoxin reductase (EhTHRase) protein which showed significant binding affinity in the active site. Out of the six actives, some of the compounds showed lipophilic characteristics. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Down-regulation of flavin reductase and alcohol dehydrogenase-1 (ADH1) in metronidazole-resistant isolates of Trichomonas vaginalis

    PubMed Central

    Leitsch, David; Drinić, Mirjana; Kolarich, Daniel; Duchêne, Michael

    2012-01-01

    The microaerophilic parasite Trichomonas vaginalis is a causative agent of painful vaginitis or urethritis, termed trichomoniasis, and can also cause preterm delivery or stillbirth. Treatment of trichomoniasis is almost exclusively based on the nitroimidazole drugs metronidazole and tinidazole. Metronidazole resistance in T. vaginalis does occur and is often associated with treatment failure. In most cases, metronidazole-resistant isolates remain susceptible to tinidazole, but cross resistance between the two closely related drugs can be a problem. In this study we measured activities of thioredoxin reductase and flavin reductase in four metronidazole-susceptible and five metronidazole-resistant isolates. These enzyme activities had been previously found to be downregulated in T. vaginalis with high-level metronidazole resistance induced in the laboratory. Further, we aimed at identifying factors causing metronidazole resistance and compared the protein expression profiles of all nine isolates by application of two-dimensional gel electrophoresis (2DE). Thioredoxin reductase activity was nearly equal in all strains assayed but flavin reductase activity was clearly down-regulated, or even absent, in metronidazole-resistant strains. Since flavin reductase has been shown to reduce oxygen to hydrogen peroxide, its down-regulation could significantly contribute to the impairment of oxygen scavenging as reported by others for metronidazole-resistant strains. Analysis by 2DE revealed down-regulation of alcohol dehydrogenase 1 (ADH1) in strains with reduced sensitivity to metronidazole, an enzyme that could be involved in detoxification of intracellular acetaldehyde. PMID:22449940

  16. Characterization of catabolic meta-nitrophenol nitroreductase from Cupriavidus necator JMP134.

    PubMed

    Yin, Ying; Xiao, Yi; Liu, Hai-Zhou; Hao, Fuhua; Rayner, Simon; Tang, Huiru; Zhou, Ning-Yi

    2010-08-01

    Cupriavidus necator JMP134 utilizes meta-nitrophenol (MNP) as a sole source of carbon, nitrogen, and energy. The metabolic reconstruction of MNP degradation performed in silico suggested that the mnp cluster might have played important roles in MNP degradation. In order to experimentally confirm the prediction, we have now characterized mnpA-encoded meta-nitrophenol nitroreductase involved in the initial reaction of MNP degradation. Real-time PCR analysis indicated that mnpA played an essential role in MNP degradation. MnpA was purified to homogeneity as His-tagged proteins and was considered to be a dimer as determined by gel filtration. MnpA was an MNP nitroreductase with a tightly bound flavin mononucleotide (FMN), catalyzing the partial reduction of MNP to meta-hydroxylaminophenol via meta-nitrosophenol in the presence of NADPH and oxygen. The accumulation of meta-nitrosophenol was confirmed with the results of liquid chromatography-diode array detection and time-of-flight mass spectrometry for the first time. The low K (m) and high k (cat) of MnpA as well as MNP-inducible transcription of mnpA suggested that MNP was the physiological substrate for this nitroreductase. In addition, the phylogenetic analysis revealed that nitroreductases of known physiological function including MnpA constituted a new clade in the nitro-FMN-reductase superfamily.

  17. Real time detection of live microbes using a highly sensitive bioluminescent nitroreductase probe.

    PubMed

    Wong, Roger H F; Kwong, Thomas; Yau, Kwok-Hei; Au-Yeung, Ho Yu

    2015-03-14

    A highly sensitive and selective nitroreductase probe, showing a rapid and strong bioluminescence enhancement (>100-fold in 5 minutes), and its initial application in the real time detection of both Gram positive and Gram negative live bacteria and monitoring of their growth has been reported.

  18. Two Atypical l-Cysteine-regulated NADPH-dependent Oxidoreductases Involved in Redox Maintenance, l-Cystine and Iron Reduction, and Metronidazole Activation in the Enteric Protozoan Entamoeba histolytica*

    PubMed Central

    Jeelani, Ghulam; Husain, Afzal; Sato, Dan; Ali, Vahab; Suematsu, Makoto; Soga, Tomoyoshi; Nozaki, Tomoyoshi

    2010-01-01

    We discovered novel catalytic activities of two atypical NADPH-dependent oxidoreductases (EhNO1/2) from the enteric protozoan parasite Entamoeba histolytica. EhNO1/2 were previously annotated as the small subunit of glutamate synthase (glutamine:2-oxoglutarate amidotransferase) based on similarity to authentic bacterial homologs. As E. histolytica lacks the large subunit of glutamate synthase, EhNO1/2 were presumed to play an unknown role other than glutamine/glutamate conversion. Transcriptomic and quantitative reverse PCR analyses revealed that supplementation or deprivation of extracellular l-cysteine caused dramatic up- or down-regulation, respectively, of EhNO2, but not EhNO1 expression. Biochemical analysis showed that these FAD- and 2[4Fe-4S]-containing enzymes do not act as glutamate synthases, a conclusion which was supported by phylogenetic analyses. Rather, they catalyze the NADPH-dependent reduction of oxygen to hydrogen peroxide and l-cystine to l-cysteine and also function as ferric and ferredoxin-NADP+ reductases. EhNO1/2 showed notable differences in substrate specificity and catalytic efficiency; EhNO1 had lower Km and higher kcat/Km values for ferric ion and ferredoxin than EhNO2, whereas EhNO2 preferred l-cystine as a substrate. In accordance with these properties, only EhNO1 was observed to physically interact with intrinsic ferredoxin. Interestingly, EhNO1/2 also reduced metronidazole, and E. histolytica transformants overexpressing either of these proteins were more sensitive to metronidazole, suggesting that EhNO1/2 are targets of this anti-amebic drug. To date, this is the first report to demonstrate that small subunit-like proteins of glutamate synthase could play an important role in redox maintenance, l-cysteine/l-cystine homeostasis, iron reduction, and the activation of metronidazole. PMID:20592025

  19. Structural and Mechanistic Insights into the Pseudomonas fluorescens 2-Nitrobenzoate 2-Nitroreductase NbaA.

    PubMed

    Kim, Yong-Hak; Song, Wooseok; Kim, Jin-Sik; Jiao, Li; Lee, Kangseok; Ha, Nam-Chul

    2015-08-01

    The bacterial 2-nitroreductase NbaA is the primary enzyme initiating the degradation of 2-nitrobenzoate (2-NBA), and its activity is controlled by posttranslational modifications. To date, the structure of NbaA remains to be elucidated. In this study, the crystal structure of a Cys194Ala NbaA mutant was determined to a 1.7-Å resolution. The substrate analog 2-NBA methyl ester was used to decipher the substrate binding site by inhibition of the wild-type NbaA protein. Tandem mass spectrometry showed that 2-NBA methyl ester produced a 2-NBA ester bond at the Tyr193 residue in the wild-type NbaA but not residues in the Tyr193Phe mutant. Moreover, covalent binding of the 2-NBA methyl ester to Tyr193 reduced the reactivity of the Cys194 residue on the peptide link. The Tyr193 hydroxyl group was shown to be essential for enzyme catalysis, as a Tyr193Phe mutant resulted in fast dissociation of flavin mononucleotide (FMN) from the protein with the reduced reactivity of Cys194. FMN binding to NbaA varied with solution NaCl concentration, which was related to the catalytic activity but not to cysteine reactivity. These observations suggest that the Cys194 reactivity is negatively affected by a posttranslational modification of the adjacent Tyr193 residue, which interacts with FMN and the substrate in the NbaA catalytic site. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  20. Ablation of central nervous system progenitor cells in transgenic rats using bacterial nitroreductase system.

    PubMed

    Kwak, Seung P; Malberg, Jessica E; Howland, David S; Cheng, Ke-Yi; Su, Jianying; She, Yin; Fennell, Myles; Ghavami, Afshin

    2007-05-01

    Specific ablation of central nervous system (CNS) progenitor cells in the brain of live animals is a powerful method to determine the functions of these cells and to reveal novel avenues for the treatment of several CNS-related disorders. To achieve this goal, we generated a line of transgenic rats expressing a bacterial enzyme, Escherichia coli nitroreductase gene (NTR), under control of the nestin promoter. In this system, NTR(+) cells are selectively eliminated upon application of prodrug CB1954, through activation of programmed cell death machineries. At 5 days of age, which is a time when cerebellar development is occurring, transgenic rats bearing the nestin-NTR/green fluorescent protein (GFP) gene are overtly normal and express NTR/GFP in neuronal stem cells, without any toxicity in these cells. The functional consequence of progenitor cell ablation was demonstrated by administering prodrug CB1954 into the cerebellum at this 5-day time point. Stem cell ablation in these neonates resulted in sensorimotor abnormalities, cerebellar degeneration, overall reduction in cerebellar seize, and manifestation of ataxia. In adult rats, GFP expression was not seen in the hippocampal progenitor cells and seen only at very low levels in the lateral ventricles, indicating a different NTR/GFP expression pattern between neonates and adults. In addition, application of CB1954 by intraventricular delivery reduced the number of 5-bromo-2'-deoxyuridine-labeled proliferating cells in the lateral ventricle but not hippocampus of NTR/GFP rats. These findings shows that targeted expression of NTR under a specific promoter might be of significant value in addressing the function of distinct cell population in vivo.

  1. Purification and characterization of nitrobenzene nitroreductase from Pseudomonas pseudoalcaligenes JS45.

    PubMed Central

    Somerville, C C; Nishino, S F; Spain, J C

    1995-01-01

    Pseudomonas pseudoalcaligenes JS45 grows on nitrobenzene as a sole source of carbon, nitrogen, and energy. The catabolic pathway involves reduction to hydroxylaminobenzene followed by rearrangement to o-amino-phenol and ring fission (S. F. Nishino and J. C. Spain, Appl. Environ. Microbiol. 59:2520, 1993). A nitrobenzene-inducible, oxygen-insensitive nitroreductase was purified from extracts of JS45 by ammonium sulfate precipitation followed by anion-exchange and gel filtration chromatography. A single 33-kDa polypeptide was detected by denaturing gel electrophoresis. The size of the native protein was estimated to be 30 kDa by gel filtration. The enzyme is a flavoprotein with a tightly bound flavin mononucleotide cofactor in a ratio of 2 mol of flavin per mol of protein. The Km for nitrobenzene is 5 microM at an initial NADPH concentration of 0.5 mM. The Km for NADPH at an initial nitrobenzene concentration of 0.1 mM is 183 microM. Nitrosobenzene was not detected as an intermediate of nitrobenzene reduction, but nitrosobenzene is a substrate for the enzyme, and the specific activity for nitrosobenzene is higher than that for nitrobenzene. These results suggest that nitrosobenzene is formed but is immediately reduced to hydroxylaminobenzene. Hydroxylaminobenzene was the only product detected after incubation of the purified enzyme with nitrobenzene and NADPH. Hydroxylaminobenzene does not serve as a substrate for further reduction by this enzyme. The products and intermediates are consistent with two two-electron reductions of the parent compound. Furthermore, the low Km and the inducible control of enzyme synthesis suggest that nitrobenzene is the physiological substrate for this enzyme. PMID:7601851

  2. Oxygen-Insensitive Nitroreductases NfsA and NfsB of Escherichia coli Function under Anaerobic Conditions as Lawsone-Dependent Azo Reductases

    PubMed Central

    Rau, Jörg; Stolz, Andreas

    2003-01-01

    Quinones can function as redox mediators in the unspecific anaerobic reduction of azo compounds by various bacterial species. These quinones are enzymatically reduced by the bacteria and the resulting hydroquinones then reduce in a purely chemical redox reaction the azo compounds outside of the cells. Recently, it has been demonstrated that the addition of lawsone (2-hydroxy-1,4-naphthoquinone) to anaerobically incubated cells of Escherichia coli resulted in a pronounced increase in the reduction rates of different sulfonated and polymeric azo compounds. In the present study it was attempted to identify the enzyme system(s) responsible for the reduction of lawsone by E. coli and thus for the lawsone-dependent anaerobic azo reductase activity. An NADH-dependent lawsone reductase activity was found in the cytosolic fraction of the cells. The enzyme was purified by column chromatography and the amino-terminal amino acid sequence of the protein was determined. The sequence obtained was identical to the sequence of an oxygen-insensitive nitroreductase (NfsB) described earlier from this organism. Subsequent biochemical tests with the purified lawsone reductase activity confirmed that the lawsone reductase activity detected was identical with NfsB. In addition it was proven that also a second oxygen-insensitive nitroreductase of E. coli (NfsA) is able to reduce lawsone and thus to function under adequate conditions as quinone-dependent azo reductase. PMID:12788749

  3. Efficient Two-Photon Fluorescent Probe for Nitroreductase Detection and Hypoxia Imaging in Tumor Cells and Tissues.

    PubMed

    Zhang, Jing; Liu, Hong-Wen; Hu, Xiao-Xiao; Li, Jin; Liang, Li-Hui; Zhang, Xiao-Bing; Tan, Weihong

    2015-12-01

    Hypoxia plays an important role in tumor progression, and the development of efficient methods for monitoring hypoxic degree in living systems is of great biomedical importance. In the solid tumors, the nitroreductase level is directly corresponded with the hypoxic status. Many one-photon excited fluorescent probes have been developed for hypoxia imaging in tumor cells via the detection of nitroreductase level. However, two-photon excited probes are more suitable for bioimaging. In this work, a two-photon probe 1 for nitroreductase detection and hypoxic status monitoring in living tumor cells and tissues was reported for the first time. The detection is based on the fact that the nitro-group of probe 1 could be selectively reduced to an amino-group by nitroreductase in the presence of reduced NADH, following by a 1,6-rearrangement-elimination to release the fluorophore, resulting in the enhancement of fluorescence. The probe exhibited both one-photon and two-photon excited remarkable fluorescence enhancement (∼70-fold) for nitroreductase, which afforded a high sensitivity for nitroreductase, with a detection limit of 20 ng/mL observed. Moreover, the applications of the probe for fluorescent bioimaging of hypoxia in living cells and two-photon bioimaging in tissues were carried out, with tissue-imaging depths of 70-160 μm observed, which demonstrates its practical application in complex biosystems.

  4. Metronidazole and the immune system.

    PubMed

    Shakir, L; Javeed, A; Ashraf, M; Riaz, A

    2011-06-01

    Metronidazole (MTZ) is a nitroimidazole antibiotic used mainly for the treatment of infections caused by susceptible organisms, particularly anaerobic bacteria and protozoa. Distinct from its antibiotic, amoebicidal, and antiprotozoal effects, MTZ displays immunopharmacological behaviour. This review outlines multiple effects of MTZ on different aspects of immunity, including innate and acquired immunity, and also highlights the immunopharmacological behaviour of MTZ in terms of its relevance to inflammation, delayed type hypersensitivity (DTH) and graft versus host disease (GVHD).

  5. Formulation development and evaluation of metronidazole magnetic nanosuspension as a magnetic-targeted and polymeric-controlled drug delivery system

    NASA Astrophysics Data System (ADS)

    Latha, Subbiah; Selvamani, Palanisamy; Kumar, Chelladurai Senthil; Sharavanan, Palaniappan; Suganya, Govindan; Beniwal, Vijender Singh; Rao, Poduri Rama

    2009-05-01

    A nanosuspension of magnetically tagged metronidazole was developed by the solvent displacement method coupled with ultrasonication and was evaluated for its physicochemical properties. The drug release from metronidazole magnetic nanosuspension at pH 1.2 and 7.0 shows maximum correlation coefficient for zero order and Higuchi model, respectively. The anthelmintic activity of the formulated metronidazole magnetic nanosuspension was evaluated on Indian earthworms (Pheretima poi). Metronidazole magnetic nanosuspension at a dose of 10 and 50 mg/ml shortened by 31% and 34%, respectively, the mean time to death of the earthworms when compared against a non-magnetic metronidazole suspension. Thus, the developed metronidazole magnetic nanosuspension showed potent, controlled and targeted drug action and might be a good therapeutic avenue in combating infectious GI disorders.

  6. Effects of metronidazole (Flagyl) on the determination of serum ASAT on the SMA 12/60 Auto Analyser.

    PubMed

    Karlsen, R L; Kristiansen, G; Solberg, J H

    1983-04-01

    Therapeutic serum concentrations of metronidazole will lead to under-estimation of ASAT activity when a SMA 12/60 Auto Analyser is used. This interference is due to metronidazole entering the colorimeter through the dialyser membrane in the SMA 12/60 Auto Analyser. This drug is one of the few with a relatively high therapeutic serum concentration, absorbing light in the 340 nm range. Metronidazole will similarily affect other 340 nm methods (LDH, ALAT) available on the SMA 12/60. This interference with metronidazole on the SMA 12/60 can easily be solved by the introduction of a separate serum blank channel for the 340 nm methods.

  7. Treatment of trichomoniasis with metronidazole rectal suppositories

    PubMed Central

    Panja, S K

    1982-01-01

    Since a single dose of metronidazole in suppository form is very effective in the prevention of postoperative Gram-negative anaerobic infections, 84 patients with vaginal trichomoniasis were treated with metronidazole suppositories (two 1-g suppositories in a single dose). The cure rate in this series was 94%. PMID:7104657

  8. Toxic metronidazole-induced MRI changes.

    PubMed

    Horlen, C K; Seifert, C F; Malouf, C S

    2000-11-01

    To report a case of changes documented by magnetic resonance imaging (MRI) of the head probably due to accumulation of metronidazole in a patient with liver dysfunction. A 34-year-old Hispanic man with cirrhosis and hepatitis C being treated with metronidazole for Bacteroides fragilis meningitis and bacteremia developed ataxia, disorientation, and peripheral neuropathy. An MRI at the time meningitis was diagnosed was negative. After the patient received > 60 g of metronidazole, an MRI revealed increased signal intensity below, behind, and lateral to the fourth ventricle. Concomitant metronidazole serum concentration was toxic at 35.1 micrograms/mL. This is the second reported case of metronidazole-induced MRI changes. Metronidazole is known to accumulate in patients with liver dysfunction and can cause peripheral neuropathy and central nervous system (CNS) dysfunction; these effects may take up to two years to completely resolve. Metronidazole dosages should be reduced in patients with liver dysfunction to prevent the accumulation of metronidazole, which can lead to CNS dysfunction and peripheral neuropathy.

  9. [Is combining metronidazole and alcohol really hazardous?].

    PubMed

    Fjeld, Hilde; Raknes, Guttorm

    2014-09-16

    It is common practice to warn against intake of alcohol (ethanol) when taking metronidazole because of the risk of an effect similar to disulfiram (Antabuse). In this article we investigate whether such a warning has any real basis. KNOWLEDGE BASE: The article is based on a review of relevant literature retrieved through a search in PubMed. A search was also made in the WHO's database on adverse effects. No in-vitro studies, animal models, reports of adverse effects or clinical studies provide any convincing evidence of a disulfiram-like interaction between ethanol and metronidazole. The warning against simultaneous use of alcohol and metronidazole appear to be based on laboratory experiments and individual case histories in which the reported reactions are equally likely to have been caused by ethanol alone or by adverse effects of metronidazole. Recent research does not confirm a clinically relevant interaction between ethanol and metronidazole.

  10. The Nitroreductase System of Inducible Targeted Ablation Facilitates Cell-specific Regenerative Studies in Zebrafish

    PubMed Central

    White, David T.; Mumm, Jeff S.

    2013-01-01

    At the turn of the 20th century, classical regenerative biology – the study of organismal/tissue/limb regeneration in animals such as crayfish, snails, and planaria – garnered much attention. However, scientific luminaries such as Thomas Hunt Morgan eventually turned to other fields after concluding that inquiries into regenerative mechanisms were largely intractable beyond observational intrigues. The field of regeneration has enjoyed a resurgence in research activity at the turn of the 21st century, in large part due to “the promise” of cultured stem cells regarding reparative therapeutic approaches. Additionally, genomics-based methods that allow sophisticated genetic/molecular manipulations to be carried out in nearly any species have extended organismal regenerative biology well beyond observational limits. Throughout its history, complex paradigms such as limb regeneration – involving multiple tissue/cell types, thus, potentially multiple stem cell subtypes – have predominated the regenerative biology field. Conversely, cellular regeneration – the replacement of specific cell types – has been studied from only a few perspectives (predominantly muscle and mechanosensory hair cells). Yet, many of the degenerative diseases that regenerative biology hopes to address involve the loss of individual cell types; thus, a primary emphasis of the embryonic/induced stem cell field is defining culture conditions which promote cell-specific differentiation. Here we will discuss recent methodological approaches that promote the study of cell-specific regeneration. Such paradigms can reveal how the differentiation of specific cell types and regenerative potential of discrete stem cell niches are regulated. In particular, we will focus on how the nitroreductase (NTR) system of inducible targeted cell ablation facilitates: 1) large-scale genetic and chemical screens for identifying factors that regulate regeneration and, 2) in vivo time-lapse imaging

  11. The nitroreductase system of inducible targeted ablation facilitates cell-specific regenerative studies in zebrafish.

    PubMed

    White, David T; Mumm, Jeff S

    2013-08-15

    At the turn of the 20th century, classical regenerative biology--the study of organismal/tissue/limb regeneration in animals such as crayfish, snails, and planaria--garnered much attention. However, scientific luminaries such as Thomas Hunt Morgan eventually turned to other fields after concluding that inquiries into regenerative mechanisms were largely intractable beyond observational intrigues. The field of regeneration has enjoyed a resurgence in research activity at the turn of the 21st century, in large part due to "the promise" of cultured stem cells regarding reparative therapeutic approaches. Additionally, genomics-based methods that allow sophisticated genetic/molecular manipulations to be carried out in nearly any species have extended organismal regenerative biology well beyond observational limits. Throughout its history, complex paradigms such as limb regeneration--involving multiple tissue/cell types, thus, potentially multiple stem cell subtypes--have predominated the regenerative biology field. Conversely, cellular regeneration--the replacement of specific cell types--has been studied from only a few perspectives (predominantly muscle and mechanosensory hair cells). Yet, many of the degenerative diseases that regenerative biology hopes to address involve the loss of individual cell types; thus, a primary emphasis of the embryonic/induced stem cell field is defining culture conditions which promote cell-specific differentiation. Here we will discuss recent methodological approaches that promote the study of cell-specific regeneration. Such paradigms can reveal how the differentiation of specific cell types and regenerative potential of discrete stem cell niches are regulated. In particular, we will focus on how the nitroreductase (NTR) system of inducible targeted cell ablation facilitates: (1) large-scale genetic and chemical screens for identifying factors that regulate regeneration and (2) in vivo time-lapse imaging experiments aimed at

  12. Efficacy and Safety of Metronidazole for Pulmonary Multidrug-Resistant Tuberculosis

    PubMed Central

    Carroll, Matthew W.; Jeon, Doosoo; Mountz, James M.; Lee, Jong Doo; Jeong, Yeon Joo; Zia, Nadeem; Lee, Myungsun; Lee, Jongseok; Via, Laura E.; Lee, Soyoung; Eum, Seok-Yong; Lee, Sung-Joong; Goldfeder, Lisa C.; Cai, Ying; Jin, Boyoung; Kim, Youngran; Oh, Taegwon; Chen, Ray Y.; Dodd, Lori E.; Gu, Wenjuan; Dartois, Veronique; Park, Seung-Kyu; Kim, Cheon Tae

    2013-01-01

    Pulmonary lesions from active tuberculosis patients are thought to contain persistent, nonreplicating bacilli that arise from hypoxic stress. Metronidazole, approved for anaerobic infections, has antituberculosis activity against anoxic bacilli in vitro and in some animal models and may target persistent, nonreplicating bacilli. In this double-blind, placebo-controlled trial, pulmonary multidrug-resistant tuberculosis subjects were randomly assigned to receive metronidazole (500 mg thrice daily) or placebo for 8 weeks in addition to an individualized background regimen. Outcomes were measured radiologically (change on high-resolution computed tomography [HRCT]), microbiologically (time to sputum smear and culture conversion), and clinically (status 6 months after stopping therapy). Enrollment was stopped early due to excessive peripheral neuropathies in the metronidazole arm. Among 35 randomized subjects, 31 (15 metronidazole, 16 placebo) were included in the modified intent-to-treat analysis. There were no significant differences by arm in improvement of HRCT lesions from baseline to 2 or 6 months. More subjects in the metronidazole arm converted their sputum smear (P = 0.04) and liquid culture (P = 0.04) to negative at 1 month, but these differences were lost by 2 months. Overall, 81% showed clinical success 6 months after stopping therapy, with no differences by arm. However, 8/16 (50%) of subjects in the metronidazole group and 2/17 (12%) of those in the placebo group developed peripheral neuropathy. Subjects who received metronidazole were 4.3-fold (95% confidence interval [CI], 1.1 to 17.1) more likely to develop peripheral neuropathies than subjects who received placebo. Metronidazole may have increased early sputum smear and culture conversion but was too neurotoxic to use over the longer term. Newer nitroimidazoles with both aerobic and anaerobic activity, now in clinical trials, may increase the sterilizing potency of future treatment regimens. PMID

  13. Efficacy and safety of metronidazole for pulmonary multidrug-resistant tuberculosis.

    PubMed

    Carroll, Matthew W; Jeon, Doosoo; Mountz, James M; Lee, Jong Doo; Jeong, Yeon Joo; Zia, Nadeem; Lee, Myungsun; Lee, Jongseok; Via, Laura E; Lee, Soyoung; Eum, Seok-Yong; Lee, Sung-Joong; Goldfeder, Lisa C; Cai, Ying; Jin, Boyoung; Kim, Youngran; Oh, Taegwon; Chen, Ray Y; Dodd, Lori E; Gu, Wenjuan; Dartois, Veronique; Park, Seung-Kyu; Kim, Cheon Tae; Barry, Clifton E; Cho, Sang-Nae

    2013-08-01

    Pulmonary lesions from active tuberculosis patients are thought to contain persistent, nonreplicating bacilli that arise from hypoxic stress. Metronidazole, approved for anaerobic infections, has antituberculosis activity against anoxic bacilli in vitro and in some animal models and may target persistent, nonreplicating bacilli. In this double-blind, placebo-controlled trial, pulmonary multidrug-resistant tuberculosis subjects were randomly assigned to receive metronidazole (500 mg thrice daily) or placebo for 8 weeks in addition to an individualized background regimen. Outcomes were measured radiologically (change on high-resolution computed tomography [HRCT]), microbiologically (time to sputum smear and culture conversion), and clinically (status 6 months after stopping therapy). Enrollment was stopped early due to excessive peripheral neuropathies in the metronidazole arm. Among 35 randomized subjects, 31 (15 metronidazole, 16 placebo) were included in the modified intent-to-treat analysis. There were no significant differences by arm in improvement of HRCT lesions from baseline to 2 or 6 months. More subjects in the metronidazole arm converted their sputum smear (P = 0.04) and liquid culture (P = 0.04) to negative at 1 month, but these differences were lost by 2 months. Overall, 81% showed clinical success 6 months after stopping therapy, with no differences by arm. However, 8/16 (50%) of subjects in the metronidazole group and 2/17 (12%) of those in the placebo group developed peripheral neuropathy. Subjects who received metronidazole were 4.3-fold (95% confidence interval [CI], 1.1 to 17.1) more likely to develop peripheral neuropathies than subjects who received placebo. Metronidazole may have increased early sputum smear and culture conversion but was too neurotoxic to use over the longer term. Newer nitroimidazoles with both aerobic and anaerobic activity, now in clinical trials, may increase the sterilizing potency of future treatment regimens.

  14. Possible nephotoxic interaction of lithium and metronidazole

    SciTech Connect

    Teicher, M.H.; Altesman, R.I.; Cole, J.O.; Schatzberg, A.F.

    1987-06-26

    Several classes of drugs can promote renal retention of lithium and, occasionally, can induce lithium intoxication. The antimicrobial agent metronidazole hydrochloride (Flagyl I.V.) was also implicated in producing such a reaction in one woman. The authors describe two patients who experienced toxic reactions to lithium following brief use of metronidazole. However, in these two patients, in contrast to the previous case, the degree of acute intoxication was less severe and treatment with metronidazole was completed without apparent suspicion, but persistent signs of renal damage later emerged.

  15. Metronidazole-induced encephalopathy after prolonged metronidazole course for treatment of C. difficile colitis.

    PubMed

    Godfrey, Mark S; Finn, Arkadiy; Zainah, Hadeel; Dapaah-Afriyie, Kwame

    2015-01-16

    A 65-year-old woman with a diagnosis of Clostridium difficile colitis undergoing prolonged treatment with metronidazole was admitted to hospital for altered mentation, slurred speech and weakness. She was diagnosed with metronidazole-induced encephalopathy, confirmed with brain MRI and improved when the offending agent was removed. This case report highlights encephalopathy as a complication of prolonged metronidazole treatment, which has become more common in clinical practice for the treatment of C. difficile infection.

  16. Metronidazole-induced encephalopathy after prolonged metronidazole course for treatment of C. difficile colitis

    PubMed Central

    Godfrey, Mark S; Finn, Arkadiy; Zainah, Hadeel; Dapaah-Afriyie, Kwame

    2015-01-01

    A 65-year-old woman with a diagnosis of Clostridium difficile colitis undergoing prolonged treatment with metronidazole was admitted to hospital for altered mentation, slurred speech and weakness. She was diagnosed with metronidazole-induced encephalopathy, confirmed with brain MRI and improved when the offending agent was removed. This case report highlights encephalopathy as a complication of prolonged metronidazole treatment, which has become more common in clinical practice for the treatment of C. difficile infection. PMID:25596288

  17. Potential of bisbenzimidazole-analogs toward metronidazole-resistant Trichomonas vaginalis isolates.

    PubMed

    Korosh, Travis; Bujans, Emmanuel; Morada, Mary; Karaalioglu, Canan; Vanden Eynde, Jean Jacques; Mayence, Annie; Huang, Tien L; Yarlett, Nigel

    2017-10-01

    A bisoxyphenylene-bisbenzimidazole series with increasing aliphatic chain length (CH2 to C10 H20 ) containing a meta- (m) or para (p)-benzimidazole linkage to the phenylene ring was tested for ability to inhibit the growth of metronidazole-susceptible (C1) and metronidazole-refractory (085) Trichomonas vaginalis isolates under aerobic and anaerobic conditions. Compound 3m, 2,2'-[α,ω-propanediylbis(oxy-1,3-phenylene)]bis-1H-benzimidazole, displayed a 5.5-fold lower minimum inhibitory concentration (MIC) toward T. vaginalis isolate 085 than metronidazole under aerobic growth conditions, (26 μm compared to 145 μm). A dose of 25 mg/kg per day for four days of compound 3m cured a subcutaneous mouse model infection using T. vaginalis isolates 286 (metronidazole susceptible) and 085 (metronidazole refractory). Compound 3m was weakly reduced by pyruvate:ferredoxin oxidoreductase, but unlike metronidazole was not dependent upon added ferredoxin. It is concluded from structure-activity relationships that there was no obvious trend based on the length of the central aliphatic chain, or the steric position of the bisbenzimidazole enabling prediction of biological activity. The compounds generally fulfill Lipinski's rile of five, indicating their potential as drug leads. © 2017 John Wiley & Sons A/S.

  18. PHARMACOKINETICS OF A SINGLE DOSE OF METRONIDAZOLE AFTER RECTAL ADMINISTRATION IN CAPTIVE ASIAN ELEPHANTS (ELEPHAS MAXIMUS).

    PubMed

    Sander, Samantha J; Siegal-Willott, Jessica L; Ziegler, Jessie; Lee, Elizabeth; Tell, Lisa; Murray, Suzan

    2016-03-01

    Metronidazole is a nitroimidazole antibacterial and antiprotozoal drug with bacteriocidal activity against a broad range of anaerobic bacteria. It is a recognized treatment for elephants diagnosed with anaerobic bacterial infection or protozoal disease or exhibiting signs of colonic impaction, diarrhea, and colic. This study evaluated the pharmacokinetics of rectally administered metronidazole (15 mg/kg) in five adult female Asian elephants (Elephas maximus). Serum samples were collected from each animal for 96 hr after rectal administration of metronidazole. Serum concentrations of metronidazole and its primary metabolite, hydroxymetronidazole, were measured via ultraperformance liquid chromatography. Data were analyzed via a noncompartmental pharmacokinetic approach. Results indicated that serum levels of metronidazole were quantifiable at the 0.25 hr time point and absent in all elephants by the 96 hr time point. The serum peak concentration (mean ± SD, 13.15 ± 2.59 μg/ml) and area under the curve from time 0 to infinity (mean ± SD, 108.79 ± 24.77 hr × μg/ml) were higher than that reported in domestic horses after similar usage. Concurrently, the time of maximum serum concentration (mean ± SD, 1.2 ± 0.45 hr) and terminal elimination half-life (harmonic mean ± pseudo-SD, 7.85 ± 0.93 hr) were longer when compared to equine reports. Rectal administration of metronidazole was well tolerated and rapidly absorbed in all study elephants. Based on the findings in this study, metronidazole administered at a single dose of 15 mg/kg per rectum in the Asian elephant is likely to result in serum concentrations above 4 μg/ml for 8 hr and above 2 μg/ml for 24 hr after treatment is administered. Dosing recommendations should reflect the mean inhibitory concentration of metronidazole for each pathogen.

  19. A case of metronidazole-resistant Trichomonas vaginalis in pregnancy.

    PubMed

    Forbes, Georgina L; Drayton, Rachel; Forbes, Gavin D

    2016-09-01

    Trichomonas vaginalis is a sexually transmitted protozoan infection resulting in vulvo-vaginitis and altered vaginal discharge in symptomatic women. Trichomoniasis has been implicated in causing adverse pregnancy outcomes such as low birth weight and pre-term labour. Metronidazole is the recommended first-line treatment for trichomonal infection. Other nitroimidazoles, such as tinidazole, are used as alternative regimens with similar activity but at a greater expense. Treatment failure usually represents patient non-compliance or re-infection, although metronidazole resistance has previously been documented. Antimicrobial susceptibility testing for T. vaginalis is currently not available in the UK. Patients with disease unresponsive to first-line treatments pose a major challenge, as therapeutic options are limited. We present the case of a patient with presumed resistant infection during pregnancy, and the additional treatment issues that this presented. © The Author(s) 2015.

  20. Evaluation of polycaprolactone matrices for the intravaginal delivery of metronidazole in the treatment of bacterial vaginosis.

    PubMed

    Pathak, Meenakshi; Turner, Mark; Palmer, Cheryn; Coombes, Allan G A

    2014-09-01

    Microporous, poly (ɛ-caprolactone) (PCL) matrices loaded with the antibacterial, metronidazole were produced by rapidly cooling suspensions of drug powder in PCL solutions in acetone. Drug incorporation in the matrices increased from 2.0% to 10.6% w/w on raising the drug loading of the PCL solution from 5% to 20% w/w measured with respect to the PCL content. Drug loading efficiencies of 40-53% were obtained. Rapid 'burst release' of 35-55% of the metronidazole content was recorded over 24 h when matrices were immersed in simulated vaginal fluid (SVF), due to the presence of large amounts of drug on matrix surface as revealed by Raman microscopy. Gradual release of around 80% of the drug content occurred over the following 12 days. Metronidazole released from PCL matrices in SVF retained antimicrobial activity against Gardnerella vaginalis in vitro at levels up to 97% compared to the free drug. Basic modelling predicted that the concentrations of metronidazole released into vaginal fluid in vivo from a PCL matrix in the form of an intravaginal ring would exceed the minimum inhibitory concentration of metronidazole against G. vaginalis. These findings recommend further investigation of PCL matrices as intravaginal devices for controlled delivery of metronidazole in the treatment and prevention of bacterial vaginosis. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  1. Trichomonas vaginalis Flavin Reductase 1 and its Role in Metronidazole Resistance

    PubMed Central

    Leitsch, David; Janssen, Brian D.; Kolarich, Daniel; Johnson, Patricia J.; Duchêne, Michael

    2015-01-01

    Summary The enzyme flavin reductase 1 (FR1) from Trichomonas vaginalis, formerly known as NADPH oxidase, was isolated and identified. Flavin reductase is part of the antioxidative defense in T. vaginalis and indirectly reduces molecular oxygen to hydrogen peroxide via free flavins. Importantly, a reduced or absent flavin reductase activity has been reported in metronidazole-resistant T. vaginalis, resulting in elevated intracellular oxygen levels and futile cycling of metronidazole. Interestingly, FR1 has no close homologue in any other sequenced genome, but seven full-length and three truncated isoforms exist in the T. vaginalis genome. However, out of these, only FR1 has an affinity for flavins, i.e. FMN, FAD, and riboflavin, which is high enough to be of physiological relevance. Although there are no relevant changes in the gene sequence or any alterations of the predicted FR1-mRNA structure in any of the strains studied, FR1 is not expressed in highly metronidazole-resistant strains. Transfection of a metronidazole-resistant clinical isolate (B7268), which does not express any detectable amounts of FR, with a plasmid bearing a functional FR1 gene nearly completely restored metronidazole sensitivity. Our results indicate that FR1 has a significant role in the emergence of metronidazole resistance in T. vaginalis. PMID:24256032

  2. Trichomonas vaginalis flavin reductase 1 and its role in metronidazole resistance.

    PubMed

    Leitsch, David; Janssen, Brian D; Kolarich, Daniel; Johnson, Patricia J; Duchêne, Michael

    2014-01-01

    The enzyme flavin reductase 1 (FR1) from Trichomonas vaginalis, formerly known as NADPH oxidase, was isolated and identified. Flavin reductase is part of the antioxidative defence in T. vaginalis and indirectly reduces molecular oxygen to hydrogen peroxide via free flavins. Importantly, a reduced or absent flavin reductase activity has been reported in metronidazole-resistant T. vaginalis, resulting in elevated intracellular oxygen levels and futile cycling of metronidazole. Interestingly, FR1 has no close homologue in any other sequenced genome, but seven full-length and three truncated isoforms exist in the T. vaginalis genome. However, out of these, only FR1 has an affinity for flavins, i.e. FMN, FAD and riboflavin, which is high enough to be of physiological relevance. Although there are no relevant changes in the gene sequence or any alterations of the predicted FR1-mRNA structure in any of the strains studied, FR1 is not expressed in highly metronidazole-resistant strains. Transfection of a metronidazole-resistant clinical isolate (B7268), which does not express any detectable amounts of FR, with a plasmid bearing a functional FR1 gene nearly completely restored metronidazole sensitivity. Our results indicate that FR1 has a significant role in the emergence of metronidazole resistance in T. vaginalis.

  3. Bi-functionalization of a calcium phosphate-coated titanium surface with slow-release simvastatin and metronidazole to provide antibacterial activities and pro-osteodifferentiation capabilities.

    PubMed

    Liu, Yunsong; Zhang, Xiao; Liu, Yang; Jin, Xiaoxiao; Fan, Cong; Ye, Hongqiang; Ou, Meng'en; Lv, Longwei; Wu, Gang; Zhou, Yongsheng

    2014-01-01

    Coating the surface of titanium implants or other bone graft substitute materials with calcium phosphate (Ca-P) crystals is an effective way to enhance the osteoconduction of the implants. Ca-P coating alone cannot confer pro-osteodifferentiation and antibacterial capabilities on implants; however, it can serve as a carrier for biological agents which could improve the performance of implants and bone substitutes. Here, we constructed a novel, bi-functional Ca-P coating with combined pro-osteodifferentiation and antibacterial capabilities. Different concentrations of metronidazole (MNZ) and simvastatin (SIM) were integrated into biomimetic Ca-P coatings on the surface of titanium disks. The biological effects of this bi-functional biomimetic coating on human bone marrow mesenchymal stem cells (hBMMSCs), human adipose derived stromal cells (hASCs), and Porphyromonas gingivalis were assessed in vitro. We observed that Ca-P coatings loaded with both SIM and MNZ display favorable release kinetics without affecting cell proliferation or attachment. In the inhibition zone test, we found that the bi-functional coating showed lasting antibacterial effects when incubated with Porphyromonas gingivalis for 2 and 4 days. Moreover, the osteodifferentiation of hBMMSCs and hASCs were increased when cultured on this bi-functional coating for 7 and 14 days. Both drugs were loaded onto the Ca-P coating at specific concentrations (10(-5) M SIM; 10(-2) M MNZ) to achieve optimal release kinetics. Considering the safety, stability and low cost of SIM and MNZ, this novel bi-functional Ca-P coating technique represents a promising method to improve the performance of metal implants or other bone substitute materials, and can theoretically be easily translated to clinical applications.

  4. Deficiency of the ferrous iron transporter FeoAB is linked with metronidazole resistance in Bacteroides fragilis.

    PubMed

    Veeranagouda, Yaligara; Husain, Fasahath; Boente, Renata; Moore, Jane; Smith, C Jeffrey; Rocha, Edson R; Patrick, Sheila; Wexler, Hannah M

    2014-10-01

    Metronidazole is the most commonly used antimicrobial for Bacteroides fragilis infections and is recommended for prophylaxis of colorectal surgery. Metronidazole resistance is increasing and the mechanisms of resistance are not clear. A transposon mutant library was generated in B. fragilis 638R (BF638R) to identify the genetic loci associated with resistance to metronidazole. Thirty-two independently isolated metronidazole-resistant mutants had a transposon insertion in BF638R_1421 that encodes the ferrous transport fusion protein (feoAB). Deletion of feoAB resulted in a 10-fold increased MIC of metronidazole for the strain. The metronidazole MIC for the feoAB mutant was similar to that for the parent strain when grown on media supplemented with excess iron, suggesting that the increase seen in the MIC of metronidazole was due to reduced cellular iron transport in the feoAB mutant. The furA gene repressed feoAB transcription in an iron-dependent manner and disruption of furA resulted in constitutive transcription of feoAB, regardless of whether or not iron was present. However, disruption of feoAB also diminished the capacity of BF638R to grow in a mouse intraperitoneal abscess model, suggesting that inorganic ferrous iron assimilation is essential for B. fragilis survival in vivo. Selection for feoAB mutations as a result of metronidazole treatment will disable the pathogenic potential of B. fragilis and could contribute to the clinical efficacy of metronidazole. While mutations in feoAB are probably not a direct cause of clinical resistance, this study provides a key insight into intracellular metronidazole activity and the link with intracellular iron homeostasis. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy 2014. This work is written by US Government employees and is in the public domain in the US.

  5. Deficiency of the ferrous iron transporter FeoAB is linked with metronidazole resistance in Bacteroides fragilis

    PubMed Central

    Veeranagouda, Yaligara; Husain, Fasahath; Boente, Renata; Moore, Jane; Smith, C. Jeffrey; Rocha, Edson R.; Patrick, Sheila; Wexler, Hannah M.

    2014-01-01

    Background Metronidazole is the most commonly used antimicrobial for Bacteroides fragilis infections and is recommended for prophylaxis of colorectal surgery. Metronidazole resistance is increasing and the mechanisms of resistance are not clear. Methods A transposon mutant library was generated in B. fragilis 638R (BF638R) to identify the genetic loci associated with resistance to metronidazole. Results Thirty-two independently isolated metronidazole-resistant mutants had a transposon insertion in BF638R_1421 that encodes the ferrous transport fusion protein (feoAB). Deletion of feoAB resulted in a 10-fold increased MIC of metronidazole for the strain. The metronidazole MIC for the feoAB mutant was similar to that for the parent strain when grown on media supplemented with excess iron, suggesting that the increase seen in the MIC of metronidazole was due to reduced cellular iron transport in the feoAB mutant. The furA gene repressed feoAB transcription in an iron-dependent manner and disruption of furA resulted in constitutive transcription of feoAB, regardless of whether or not iron was present. However, disruption of feoAB also diminished the capacity of BF638R to grow in a mouse intraperitoneal abscess model, suggesting that inorganic ferrous iron assimilation is essential for B. fragilis survival in vivo. Conclusions Selection for feoAB mutations as a result of metronidazole treatment will disable the pathogenic potential of B. fragilis and could contribute to the clinical efficacy of metronidazole. While mutations in feoAB are probably not a direct cause of clinical resistance, this study provides a key insight into intracellular metronidazole activity and the link with intracellular iron homeostasis. PMID:25028451

  6. Possible pharmacokinetic interaction with quinidine: ciprofloxacin or metronidazole?

    PubMed

    Cooke, C E; Sklar, G E; Nappi, J M

    1996-04-01

    To discuss a potential pharmacokinetic interaction between quinidine, ciprofloxacin, and metronidazole. A 51-year-old black woman was admitted for shortness of breath, abdominal pain, and atrial fibrillation. Procainamide and diltiazem were begun for the atrial fibrillation and ciprofloxacin and metronidazole for suspected diverticulitis. The therapy was switched to quinidine on day 5 because of adverse events associated with procainamide. A trough serum quinidine concentration (SQC) on day 7 was 6.3 micrograms/mL (normal 2-5) with normal QT and QTc intervals. On day 8, the patient was discharged in normal sinus rhythm. She took her last doses of antibiotics on day 15 and a follow-up SQC on day 18 was 2.3 micrograms/mL. The possible explanations for the changes in SQCs include: (1) laboratory error, (2) compliance with medication regimen, and (3) altered hepatic metabolism. The first two are not likely in this case. The laboratory verified the elevated SQC and the patient had her prescriptions refilled within appropriate time limits. The third explanation seems more plausible. Quinidine is metabolized by the hepatic mixed-function oxidase system, specifically cytochrome P450 (CYP) 3A4. We found that metronidazole has been shown to inhibit CYP3A activity and ciprofloxacin has been shown to inhibit certain isozymes in the cytochrome P450 system as well. When metronidazole and ciprofloxacin are administered concomitantly with quinidine, clinicians should be aware of this potential interaction. Quinidine concentrations should be monitored and patients should be assessed for signs and symptoms of quinidine toxicity.

  7. Scavenging properties of metronidazole on free oxygen radicals in a skin lipid model system.

    PubMed

    Narayanan, Sabrina; Hünerbein, Andreas; Getie, Melkamu; Jäckel, Andreas; Neubert, Reinhard H H

    2007-08-01

    production through modulation of neutrophil activity and decrease in ROS concentration by exhibiting ROS scavenging properties. The remarkable clinical efficacy of metronidazole in the treatment of rosacea is probably due to its ability to decrease ROS via different mechanisms, thereby protecting skin components from induced damage.

  8. Metronidazole for the treatment of vaginal infections.

    PubMed

    Sobel, Ryan; Sobel, Jack D

    2015-05-01

    Metronidazole , undoubtedly the most widely known and used member of the nitroimidazole drug class, remains not only first line therapy for bacterial vaginosis (BV) and trichomoniasis, but serves as drug of first choice. Available and used both orally and topically with high efficacy rates, especially for trichomoniasis, nevertheless numerous unanswered questions remain regarding mechanism of action. Given the extraordinary global frequency of vaginitis due to BV and trichomoniasis, especially the high recurrence rate observed in BV, it is timely to critically examine the therapeutic role of metronidazole in management decisions. Search methodology used PUBMED literature review. In spite of many years of successful use, multiple questions exist regarding optimal dose and duration of therapy especially in the management of BV. Antimicrobial drug resistance remains uncommon in spite of extensive use. The use of metronidazole for vaginitis is reviewed in this article together with challenges to improving its more effective administration. Currently metronidazole or the family of nitroimidazoles, represent the drugs of first choice for trichomonas vaginitis and first line therapy for BV. Drug resistance for both entities remains uncommon; however, in contrast to trichomoniasis where relapse is rare, high recurrence rates are common in women with BV. Metronidazole appears to allow persistence of vaginal microbiome microorganisms which translate into frequent relapses. In the absence of new therapeutic alternatives, strategies are being developed to enhance drug cure rates.

  9. Artifactual Depression of Serum Glutamic Oxaloacetic Transaminase by Metronidazole

    PubMed Central

    Rissing, J. Peter; Newman, Cheryl; Moore, William L.

    1978-01-01

    Eighteen patients developed abnormally low serum glutamic oxaloacetic transaminase values during metronidazole therapy. Metronidazole absorbs at 340 nm, simulating reduced nicotinamide adenine dinucleotide, which is the final colorimetric product of the serum glutamic oxaloacetic transaminase assay. PMID:214030

  10. Bacteremia Caused by a Metronidazole-Resistant Prevotella sp. Strain

    PubMed Central

    Mory, Francine; Carlier, Jean-Philippe; Alauzet, Corentine; Thouvenin, Maxime; Schuhmacher, Hélène; Lozniewski, Alain

    2005-01-01

    Metronidazole resistance among Prevotella spp. is rare. We report here the first case of bacteremia due to a high-level metronidazole-resistant Prevotella sp. responsible for treatment failure. PMID:16208024

  11. Pendimethalin Nitroreductase Is Responsible for the Initial Pendimethalin Degradation Step in Bacillus subtilis Y3

    PubMed Central

    Ni, Hai-yan; Wang, Fei; Li, Na; Yao, Li; Dai, Chen; He, Qin; He, Jian

    2016-01-01

    ABSTRACT Pendimethalin [N-(1-ethylpropyl)-2,6-dinitro-3,4-xylidine] is a selective preemergence dinitroaniline herbicide. Several fungi and bacteria have been reported to degrade pendimethalin, but the enzymes or genes involved in this process have not been characterized. Nitroreduction is the initial degradation and detoxification step for pendimethalin. In this study, a pendimethalin nitroreductase (PNR), responsible for the nitroreduction of pendimethalin, was purified from the pendimethalin-degrading strain Bacillus subtilis Y3. Based on a comparison of its mass fingerprints with all of the deduced proteins from the draft genome of strain Y3, a protein annotated as a nitroreductase was identified, and its corresponding encoding gene was termed pnr. PNR was a functional homodimer with a subunit molecular mass of approximately 23 kDa. PNR reduced the C-6 nitro group of the aromatic ring of pendimethalin, yielding 2-nitro-6-amino-N-(1-ethylpropyl)-3,4-xylidine. PNR could also catalyze the nitroreduction of three other major varieties of dinitroaniline herbicides, including butralin, oryzalin, and trifluralin. However, the number of reduced nitro groups was two instead of one, which differed from the nitroreduction of pendimethalin by PNR and which may be due to the symmetry in the chemical structures of the two nitro groups. A detoxification assay revealed that 2-nitro-6-amino-N-(1-ethylpropyl)-3,4-xylidine (PNR-reduced pendimethalin) showed no inhibitory effect on the growth of Saccharomyces cerevisiae BY4741, whereas pendimethalin showed an obvious inhibitory effect on its growth, indicating the detoxification effect of pendimethalin by PNR. Therefore, PNR has potential in pendimethalin detoxification applications. This report describes an enzyme (and corresponding gene) involved in the biodegradation of pendimethalin and dinitroaniline herbicides. IMPORTANCE Pendimethalin [N-(1-ethylpropyl)-2,6-dinitro-3,4-xylidine] is a widely used selective preemergence

  12. Metronidazole removal in powder-activated carbon and concrete-containing graphene adsorption systems: Estimation of kinetic, equilibrium and thermodynamic parameters and optimization of adsorption by a central composite design.

    PubMed

    Manjunath, S V; Kumar, S Mathava; Ngo, Huu Hao; Guo, Wenshan

    2017-09-18

    Metronidazole (MNZ) removal by two adsorbents, i.e., concrete-containing graphene (CG) and powder-activated carbon (PAC), was investigated via batch-mode experiments and the outcomes were used to analyze the kinetics, equilibrium and thermodynamics of MNZ adsorption. MNZ sorption on CG and PAC has followed the pseudo-second-order kinetic model, and the thermodynamic parameters revealed that MNZ adsorption was spontaneous on PAC and non-spontaneous on CG. Subsequently, two-parameter isotherm models, i.e., Langmuir, Freundlich, Temkin, Dubinin-Radushkevich and Elovich models, were applied to evaluate the MNZ adsorption capacity. The maximum MNZ adsorption capacities ([Formula: see text]) of PAC and CG were found to be between 25.5-32.8 mg/g and 0.41-0.002 mg/g, respectively. Subsequently, the effects of pH, temperature and adsorbent dosage on MNZ adsorption were evaluated by a central composite design (CCD) approach. The CCD experiments have pointed out the complete removal of MNZ at a much lower PAC dosage by increasing the system temperature (i.e., from 20°C to 40°C). On the other hand, a desorption experiment has shown 3.5% and 1.7% MNZ removal from the surface of PAC and CG, respectively, which was insignificant compared to the sorbed MNZ on the surface by adsorption. The overall findings indicate that PAC and CG with higher graphene content could be useful in MNZ removal from aqueous systems.

  13. Metronidazole in prevention and treatment of bacteroides infections after appendicectomy.

    PubMed Central

    Willis, A T; Ferguson, I R; Jones, P H; Phillips, K D; Tearle, P V; Berry, R B; Fiddian, R V; Graham, D F; Harland, D H; Innes, D B; Mee, W M; Rothwell-Jackson, R L; Sutch, I; Kilbey, C; Edwards, D

    1976-01-01

    The frequency of non-clostridial anaerobic infection was studied in 95 patients who had undergone acute appendicectomy: 49 received prophylactic metronidazole and 46 received placebo. Anaerobic infection did not develop in any of the metronidazole-treated patients, but infections did develop in nine (19%) of the 46 controls. Metronidazole is conveniently administered by suppository to patients who cannot take oral drugs. Five patients with intra-abdominal infections caused by non-clostridial anaerobes were successfully treated with metronidazole. PMID:764935

  14. Plasma hydroxy-metronidazole/metronidazole ratio in hepatitis C virus-induced liver disease.

    PubMed

    Marchioretto, M A M; Ecclissato, C; da Silva, C M F; Cassiano, N M; Calafatti, S A; Mendonça, S; Ribeiro, M L; Bernasconi, G C R; Degger, M F; Piovesan, H; Pedrazzoli, J

    2005-03-01

    It has been suggested that the measurement of metronidazole clearance is a sensitive method for evaluating liver function. The aim of this study was to evaluate the usefulness of plasma hydroxy-metronidazole/metronidazole ratios as indicators of dynamic liver function to detect changes resulting from the various forms of chronic hepatitis C virus (HCV) infection. A total of 139 individuals were studied: 14 healthy volunteers, 22 healthy, asymptomatic, consecutive anti-HCV-positive HCV-RNA negative subjects, 81 patients with chronic hepatitis C (49 with moderate/severe chronic hepatitis and 34 with mild hepatitis), and 20 patients with cirrhosis of the liver. HCV status was determined by the polymerase chain reaction. Plasma concentrations of metronidazole and its hydroxy-metabolite were measured by reverse-phase high-performance liquid chromatography with ultraviolet detection in a blood sample collected 10 min after the end of a metronidazole infusion. Anti-HCV-positive HCV-RNA-negative individuals demonstrated a significantly reduced capacity to metabolize intravenously infused metronidazole compared to healthy individuals (0.0478 +/- 0.0044 vs 0.0742 +/- 0.0232). Liver cirrhosis patients also had a reduced plasma hydroxy-metronidazole/metronidazole ratio when compared to the other groups of anti-HCV-positive individuals (0.0300 +/- 0.0032 vs 0.0438 +/- 0.0027 (moderate/severe chronic hepatitis) vs 0.0455 +/- 0.0026 (mild chronic hepatitis) and vs 0.0478 +/- 0.0044 (anti-HCV-positive, HCV-RNA-negative individuals)). These results suggest an impairment of the metronidazole metabolizing system induced by HCV infection that lasts after viral clearance. In those patients with chronic hepatitis C, this impairment is paralleled by progression of the disease to liver cirrhosis.

  15. Putative metronidazole neurotoxicosis in a cat.

    PubMed

    Olson, E J; Morales, S C; McVey, A S; Hayden, D W

    2005-09-01

    A presumptive case of metronidazole toxicity in a 3.4-kg adult cat is described. The cat had been treated for suspected inflammatory bowel disease with an anti-inflammatory dose of prednisone and metronidazole (73.5-147 mg/kg PO q24h) for approximately 40 days prior to presentation. Clinical signs were primarily related to the central nervous system, including acute tetraparesis, unresponsiveness, tremors, and vocalization. The patient was euthanatized after 12 days of supportive care. Necropsy revealed no significant macroscopic lesions. Histologic evaluation revealed multifocal, fairly well-demarcated foci of necrosis in the brainstem, extending from the diencephalon to the medulla oblongata. To our knowledge, this is the first report to document histologic lesions associated with metronidazole administration in a cat.

  16. Pyruvate Decarboxylase, the Target for Omeprazole in Metronidazole-Resistant and Iron-Restricted Tritrichomonas foetus

    PubMed Central

    Sutak, Róbert; Tachezy, Jan; Kulda, Jaroslav; Hrdý, Ivan

    2004-01-01

    The substituted benzimidazole omeprazole, used for the treatment of human peptic ulcer disease, inhibits the growth of the metronidazole-resistant bovine pathogen Tritrichomonas foetus in vitro (MIC at which the growth of parasite cultures is inhibited by 50%, 22 μg/ml [63 μM]). The antitrichomonad activity appears to be due to the inhibition of pyruvate decarboxylase (PDC), which is the key enzyme responsible for ethanol production and which is strongly upregulated in metronidazole-resistant trichomonads. PDC was purified to homogeneity from the cytosol of metronidazole-resistant strain. The tetrameric enzyme of 60-kDa subunits is inhibited by omeprazole (50% inhibitory concentration, 16 μg/ml). Metronidazole-susceptible T. foetus, which expresses very little PDC, is only slightly affected. Omeprazole has the same inhibitory effect on T. foetus cells grown under iron-limited conditions. Similarly to metronidazole-resistant cells, T. foetus cells grown under iron-limited conditions have nonfunctional hydrogenosomal metabolism and rely on cytosolic PDC-mediated ethanol fermentation. PMID:15155220

  17. Metronidazole and spiramycin therapy of mixed Bacteroides spp. and Neisseria gonorrhoeae infection in mice.

    PubMed

    Brook, I

    1989-01-01

    The in vitro and in vivo activity of metronidazole and spiramycin, used singly or in combination, was tested in the eradication of infection caused by Bacteroides spp. and Neisseria gonorrhoeae alone or in combination. The in vitro tests consisted of determinations of the minimal inhibitory concentrations (MIC), carried out with or without the addition of a constant amount of the other antimicrobials. The MIC of both Bacteroides bivius and Bacteroides fragilis for metronidazole were significantly reduced by the addition of spiramycin (from 0.5 to 0.125 micrograms/ml). The in vivo tests were carried out in mice and consisted of measurements of the effects of the antimicrobial agents on the bacterial contents of abscesses induced by subcutaneous injection of bacterial suspension. Synergism between metronidazole and spiramycin was noted against Bacteroides spp. in abscesses caused by either Bacteroides spp. alone, or in combination with N. gonorrhoeae. Furthermore, an additional reduction in the number of N gonorrhoeae was noted in mixed infection with Bacteroides that was treated with metronidazole alone. This study demonstrates the in vitro and in vivo efficacy of the combination of metronidazole and spiramycin in the treatment of infections caused by either Bacteroides spp. alone or in combination with N. gonorrhoeae.

  18. [Metronidazole-induced reversible cerebellar lesions and peripheral neuropathy].

    PubMed

    Toumi, S; Hammouda, M; Essid, A; Medimagh, L; Slamia, L Ben; Laouani-Kechrid, C

    2009-12-01

    Metronidazole is a widely prescribed treatment for amoebic and anaerobic germ infections. Its neurologic toxicity is rare but can be serious. We report the case of a 27-year-old male patient, treated with metronidazole for a cerebral abscess. He presented with a cerebellar syndrome and peripheral neuropathy at a cumulative metronidazole dose of 60g. The MRI aspect of the cerebellar lesions in addition to their reversibility after treatment cessation led to the diagnosis of metronidazole induced neurologic toxicity. The occurrence of neurologic disorders in patients treated with metronidazole must suggest drug toxicity and lead to cessation of treatment.

  19. Metronidazole: newly recognized cause of autonomic neuropathy.

    PubMed

    Hobson-Webb, Lisa D; Roach, E Steve; Donofrio, Peter D

    2006-05-01

    Metronidazole is a commonly used antibiotic prescribed for the treatment of anaerobic and protozoal infections of the gastrointestinal and genitourinary tracts. It is associated with numerous neurologic complications, including peripheral neuropathy. Neuropathy is typically detected in patients on chronic therapy, although it has been documented in those taking large doses for acute infections. Numerous case reports have been published describing motor and sensory neuropathy, yet autonomic neuropathy has not been described with metronidazole use. A previously healthy 15-year-old girl presented with complaints of burning pain in her feet following a short course of metronidazole for vaginitis. She could obtain pain relief only by submerging her feet in ice water. Examination revealed cold and swollen lower extremities that became erythematous and very warm when removed from the ice water. Temperature perception was reduced to the upper third of the shin bilaterally. Deep tendon reflexes and strength were preserved. Nerve conduction studies demonstrated a peripheral neuropathy manifested by reduced sensory nerve and compound muscle action potentials. Reproducible sympathetic skin potential responses could not be obtained in the hand and foot, providing evidence of a concurrent autonomic neuropathy. A thorough evaluation revealed no other cause for her condition. Repeated nerve conduction studies and sympathetic skin potentials returned to normal over the course of 6 months, paralleling the patient's clinical improvement. Metronidazole is a potential cause of reversible autonomic neuropathy.

  20. Characterization of a nitroreductase with selective nitroreduction properties in the food and intestinal lactic acid bacterium Lactobacillus plantarum WCFS1.

    PubMed

    Guillén, Hugo; Curiel, Jose Antonio; Landete, José María; Muñoz, Rosario; Herraiz, Tomás

    2009-11-11

    Nitroreductases reduce nitroaromatic compounds and other oxidants in living organisms, having interesting implications in environmental and human health. A putative nitrobenzoate reductase encoding gene (lp_0050) was recently annotated in the completed DNA sequence of lactic acid bacterium Lactobacillus plantarum WCFS1 strain. In this research, this L. plantarum gene was cloned and expressed, and the corresponding protein (PnbA) was biochemically characterized. This L. plantarum PnbA reductase is a 216 amino acid residue FMN-flavoprotein, which exhibits 23% identity with Pseudomonas putida and Ralstonia eutropha nitroreductases and <11% identity with those from enterobacteria such as E. cloacae . This reductase also showed 32-43% identity (65-72% similarity) to predicted PnbA proteins from other lactic acid bacteria. It utilized a wide range of electron acceptors including dichlorophenolindophenol (DCPIP), nitroblue tetrazolium (NBT), ferricyanide, and quinones (menadione, benzoquinone), but not pyridinium cations (paraquat and N-methyl-beta-carbolines), and it was inhibited by dicoumarol and diphenyliodonium. HPLC-MS and spectroscopic data showed that it specifically catalyzed the reduction of the 4-nitroaromatic group to the corresponding hydroxylamine in the presence of NAD(P)H. Kinetics parameters (V(max) and K(m)) showed a higher efficiency for the reduction of 2,4-dinitrobenzoate than for the reduction of 4-nitrobenzoate. It was chemoselective for the reduction of 4-nitrobenzoates, being unable to reduce other nitroaromatics. Then, L. plantarum PnbA reductase might be more specific than other microbial nitroreductases that reduce a wider range of nitroaromatic compounds. The physiological and functional role of nitroreductases remain unknown; however, their presence in lactic acid bacteria widely occurring in foods and the human intestinal tract should be of further interest.

  1. A two-photon fluorescent probe for nitroreductase imaging in living cells, tissues and zebrafish under hypoxia conditions.

    PubMed

    Zhai, Baoping; Hu, Wei; Sun, Jinyu; Chi, Siyu; Lei, Yidi; Zhang, Fang; Zhong, Cheng; Liu, Zhihong

    2017-04-04

    A two-photon fluorescent probe FNTR for nitroreductase was synthesized by using 9,9-dimethyl-2-acetyl-fluoren-7-methylamino (1) as a two-photon fluorophore and a p-nitrobenzyl carbamate group as a recognition domain for nitroreductase (NTR). The probe and the fluorophore were tested under one- and two-photon modes respectively. After reacting with nitroreductase, FNTR had a 130-fold fluorescence enhancement at 563 nm in 10 min and the maximal two-photon action cross-section value was detected as 66 GM at 750 nm. The probe showed a high sensitivity with a detection limit as low as 23.67 ng ml(-1), high selectivity, low cytotoxicity and good photostability. In the presence of reduced nicotinamide adenine dinucleotide (NADH), endogenous NTR was detected in living cells, tissues and zebrafish. Cobalt chloride was used to induce chemical hypoxia to produce NTR, which generated enhanced fluorescence in cells and tumor tissues. Finally, two-photon fluorescence imaging of NTR was achieved in zebrafish at a penetration depth of up to 200 μm.

  2. Exploratory Investigation of Bacteroides fragilis Transcriptional Response during In vitro Exposure to Subinhibitory Concentration of Metronidazole.

    PubMed

    de Freitas, Michele C R; Resende, Juliana A; Ferreira-Machado, Alessandra B; Saji, Guadalupe D R Q; de Vasconcelos, Ana T R; da Silva, Vânia L; Nicolás, Marisa F; Diniz, Cláudio G

    2016-01-01

    Bacteroides fragilis, member from commensal gut microbiota, is an important pathogen associated to endogenous infections and metronidazole remains a valuable antibiotic for the treatment of these infections, although bacterial resistance is widely reported. Considering the need of a better understanding on the global mechanisms by which B. fragilis survive upon metronidazole exposure, we performed a RNA-seq transcriptomic approach with validation of gene expression results by qPCR. Bacteria strains were selected after in vitro subcultures with subinhibitory concentration (SIC) of the drug. From a wild type B. fragilis ATCC 43859 four derivative strains were selected: first and fourth subcultures under metronidazole exposure and first and fourth subcultures after drug removal. According to global gene expression analysis, 2,146 protein coding genes were identified, of which a total of 1,618 (77%) were assigned to a Gene Ontology term (GO), indicating that most known cellular functions were taken. Among these 2,146 protein coding genes, 377 were shared among all strains, suggesting that they are critical for B. fragilis survival. In order to identify distinct expression patterns, we also performed a K-means clustering analysis set to 15 groups. This analysis allowed us to detect the major activated or repressed genes encoding for enzymes which act in several metabolic pathways involved in metronidazole response such as drug activation, defense mechanisms against superoxide ions, high expression level of multidrug efflux pumps, and DNA repair. The strains collected after metronidazole removal were functionally more similar to those cultured under drug pressure, reinforcing that drug-exposure lead to drastic persistent changes in the B. fragilis gene expression patterns. These results may help to elucidate B. fragilis response during metronidazole exposure, mainly at SIC, contributing with information about bacterial survival strategies under stress conditions in their

  3. Exploratory Investigation of Bacteroides fragilis Transcriptional Response during In vitro Exposure to Subinhibitory Concentration of Metronidazole

    PubMed Central

    de Freitas, Michele C. R.; Resende, Juliana A.; Ferreira-Machado, Alessandra B.; Saji, Guadalupe D. R. Q.; de Vasconcelos, Ana T. R.; da Silva, Vânia L.; Nicolás, Marisa F.; Diniz, Cláudio G.

    2016-01-01

    Bacteroides fragilis, member from commensal gut microbiota, is an important pathogen associated to endogenous infections and metronidazole remains a valuable antibiotic for the treatment of these infections, although bacterial resistance is widely reported. Considering the need of a better understanding on the global mechanisms by which B. fragilis survive upon metronidazole exposure, we performed a RNA-seq transcriptomic approach with validation of gene expression results by qPCR. Bacteria strains were selected after in vitro subcultures with subinhibitory concentration (SIC) of the drug. From a wild type B. fragilis ATCC 43859 four derivative strains were selected: first and fourth subcultures under metronidazole exposure and first and fourth subcultures after drug removal. According to global gene expression analysis, 2,146 protein coding genes were identified, of which a total of 1,618 (77%) were assigned to a Gene Ontology term (GO), indicating that most known cellular functions were taken. Among these 2,146 protein coding genes, 377 were shared among all strains, suggesting that they are critical for B. fragilis survival. In order to identify distinct expression patterns, we also performed a K-means clustering analysis set to 15 groups. This analysis allowed us to detect the major activated or repressed genes encoding for enzymes which act in several metabolic pathways involved in metronidazole response such as drug activation, defense mechanisms against superoxide ions, high expression level of multidrug efflux pumps, and DNA repair. The strains collected after metronidazole removal were functionally more similar to those cultured under drug pressure, reinforcing that drug-exposure lead to drastic persistent changes in the B. fragilis gene expression patterns. These results may help to elucidate B. fragilis response during metronidazole exposure, mainly at SIC, contributing with information about bacterial survival strategies under stress conditions in their

  4. Overexpression of the rhamnose catabolism regulatory protein, RhaR: a novel mechanism for metronidazole resistance in Bacteroides thetaiotaomicron

    PubMed Central

    Patel, Ekta H.; Paul, Lynthia V.; Casanueva, Ana I.; Patrick, Sheila; Abratt, Valerie R.

    2009-01-01

    Objectives The aim of the investigation was to use in vitro transposon mutagenesis to generate metronidazole resistance in the obligately anaerobic pathogenic bacterium Bacteroides thetaiotaomicron, and to identify the genes involved to enable investigation of potential mechanisms for the generation of metronidazole resistance. Methods The genes affected by the transposon insertion were identified by plasmid rescue and sequencing. Expression levels of the relevant genes were determined by semi-quantitative RNA hybridization and catabolic activity by lactate dehydrogenase/pyruvate oxidoreductase assays. Results A metronidazole-resistant mutant was isolated and the transposon insertion site was identified in an intergenic region between the rhaO and rhaR genes of the gene cluster involved in the uptake and catabolism of rhamnose. Metronidazole resistance was observed during growth in defined medium containing either rhamnose or glucose. The metronidazole-resistant mutant showed improved growth in the presence of rhamnose as compared with the wild-type parent. There was increased transcription of all genes of the rhamnose gene cluster in the presence of rhamnose and glucose, likely due to the transposon providing an additional promoter for the rhaR gene, encoding the positive transcriptional regulator of the rhamnose operon. The B. thetaiotaomicron metronidazole resistance phenotype was recreated by overexpressing the rhaR gene in the B. thetaiotaomicron wild-type parent. Both the metronidazole-resistant transposon mutant and RhaR overexpression strains displayed a phenotype of higher lactate dehydrogenase and lower pyruvate oxidoreductase activity in comparison with the parent strain during growth in rhamnose. Conclusions These data indicate that overexpression of the rhaR gene generates metronidazole resistance in B. thetaiotaomicron PMID:19525515

  5. A Reprofiled Drug, Auranofin, Is Effective against Metronidazole-Resistant Giardia lamblia

    PubMed Central

    Tejman-Yarden, Noa; Miyamoto, Yukiko; Leitsch, David; Santini, Jennifer; Debnath, Anjan; Gut, Jiri; McKerrow, James H.; Reed, Sharon L.

    2013-01-01

    Giardiasis is one of the most common causes of diarrheal disease worldwide. Treatment is primarily with 5-nitro antimicrobials, particularly metronidazole. Resistance to metronidazole has been described, and treatment failures can occur in up to 20% of cases, making development of alternative antigiardials an important goal. To this end, we have screened a chemical library of 746 approved human drugs and 164 additional bioactive compounds for activity against Giardia lamblia. We identified 56 compounds that caused significant inhibition of G. lamblia growth and attachment. Of these, 15 were previously reported to have antigiardial activity, 20 were bioactive but not approved for human use, and 21 were drugs approved for human use for other indications. One notable compound of the last group was the antirheumatic drug auranofin. Further testing revealed that auranofin was active in the low (4 to 6)-micromolar range against a range of divergent G. lamblia isolates representing both human-pathogenic assemblages A and B. Most importantly, auranofin was active against multiple metronidazole-resistant strains. Mechanistically, auranofin blocked the activity of giardial thioredoxin oxidoreductase, a critical enzyme involved in maintaining normal protein function and combating oxidative damage, suggesting that this inhibition contributes to the antigiardial activity. Furthermore, auranofin was efficacious in vivo, as it eradicated infection with different G. lamblia isolates in different rodent models. These results indicate that the approved human drug auranofin could be developed as a novel agent in the armamentarium of antigiardial drugs, particularly against metronidazole-resistant strains. PMID:23403423

  6. A reprofiled drug, auranofin, is effective against metronidazole-resistant Giardia lamblia.

    PubMed

    Tejman-Yarden, Noa; Miyamoto, Yukiko; Leitsch, David; Santini, Jennifer; Debnath, Anjan; Gut, Jiri; McKerrow, James H; Reed, Sharon L; Eckmann, Lars

    2013-05-01

    Giardiasis is one of the most common causes of diarrheal disease worldwide. Treatment is primarily with 5-nitro antimicrobials, particularly metronidazole. Resistance to metronidazole has been described, and treatment failures can occur in up to 20% of cases, making development of alternative antigiardials an important goal. To this end, we have screened a chemical library of 746 approved human drugs and 164 additional bioactive compounds for activity against Giardia lamblia. We identified 56 compounds that caused significant inhibition of G. lamblia growth and attachment. Of these, 15 were previously reported to have antigiardial activity, 20 were bioactive but not approved for human use, and 21 were drugs approved for human use for other indications. One notable compound of the last group was the antirheumatic drug auranofin. Further testing revealed that auranofin was active in the low (4 to 6)-micromolar range against a range of divergent G. lamblia isolates representing both human-pathogenic assemblages A and B. Most importantly, auranofin was active against multiple metronidazole-resistant strains. Mechanistically, auranofin blocked the activity of giardial thioredoxin oxidoreductase, a critical enzyme involved in maintaining normal protein function and combating oxidative damage, suggesting that this inhibition contributes to the antigiardial activity. Furthermore, auranofin was efficacious in vivo, as it eradicated infection with different G. lamblia isolates in different rodent models. These results indicate that the approved human drug auranofin could be developed as a novel agent in the armamentarium of antigiardial drugs, particularly against metronidazole-resistant strains.

  7. Susceptibility of bacterial vaginosis (BV)-associated bacteria to secnidazole compared to metronidazole, tinidazole and clindamycin.

    PubMed

    Petrina, Melinda A B; Cosentino, Lisa A; Rabe, Lorna K; Hillier, Sharon L

    2017-05-15

    Secnidazole, a 5-nitroimidazole with a longer half-life, is structurally related to metronidazole and tinidazole. For treatment of bacterial vaginosis (BV), secnidazole is a suitable single-dose oral drug having a longer serum half-life than metronidazole. The objective of this study was to evaluate the antimicrobial susceptibility of vaginal isolates of facultative and anaerobic bacteria to secnidazole, metronidazole, tinidazole and clindamycin. A total of 605 unique BV-related bacteria and 108 isolates of lactobacilli recovered from the human vagina of US women during the years 2009-2015 were tested for antimicrobial susceptibility by the agar dilution CLSI reference method to determine the minimal inhibitory concentration (MIC). The MIC90 (μg/mL) for secnidazole was similar to metronidazole and tinidazole for Anaerococcus tetradius (secnidazole: MIC90 2; metronidazole: MIC90 2; tinidazole: MIC90 4), Atopobium vaginae (32; >128; 128), Bacteroides species (2; 2; 2), Finegoldia magna (2; 2; 4), Gardnerella vaginalis (128; 64; 32), Mageeibacillus indolicus (2; 2; 2), Megasphaera-like bacteria (0.5; 0.25; 0.5), Mobiluncus curtisii (128; >128; >128) and Mobiluncus mulieris (>128; >128; >128), Peptoniphilus lacrimalis (4; 4; 4) and Peptoniphilus harei (2; 2; 4), Porphyromonas species (0.25; 0.5; 0.25), Prevotella bivia (8; 8; 8), Prevotella amnii (2; 1; 2) and Prevotella timonensis (2; 2; 2). In this evaluation, 14 (40%) of 35 P. bivia, 5 (14%) of 35 P. amnii and 21 (58%) of 36 P. timonensis isolates were resistant to clindamycin with MIC values of >128 μg/mL. Secnidazole, like metronidazole, was superior to clindamycin for Prevotella spp., Bacteroides spp., Peptoniphilus spp., Anaerococcus tetradius and Finegoldia magna. Clindamycin had greater activity against Atopobium vaginae, Gardnerella vaginalis and Mobiluncus spp. compared to the nitroimidazoles. All 27 Lactobacillus crispatus, 26 (96%) of 27 L. jensenii, 5 (19%) of 27 L. gasseri and 18 (67%) of 27 L

  8. In vivo bacterial imaging without engineering; A novel probe-based strategy facilitated by endogenous nitroreductase enzymes.

    PubMed

    Stanton, Michael; Cronin, Michelle; Lehouritis, Panos; Tangney, Mark

    2015-01-01

    The feasibility of utilising bacteria as vectors for gene therapy is becoming increasingly recognised. This is primarily due to a number of intrinsic properties of bacteria such as their tumour targeting capabilities, their ability to carry large genetic or protein loads and the availability of well-established genetic engineering tools for a range of common lab strains. However, a number of issues relating to the use of bacteria as vectors for gene therapy need to be addressed in order for the field to progress. Amongst these is the need for the development of non-invasive detection/imaging systems for bacteria within a living host. In vivo optical imaging has advanced preclinical research greatly, and typically involves engineering of bacteria with genetic expression constructs for luminescence (e.g. the lux operon) or fluorescent proteins (GFP etc.). This requirement for genetic modification can be restrictive, where engineering is not experimentally appropriate or technologically feasible (e.g. due to lack of suitable engineering tools). We describe a novel strategy exploiting endogenous bacterial enzymatic activity to specifically activate an exogenously administered fluorescent imaging probe. The red shifted, quenched fluorophore CytoCy5S is reduced to a fluorescent form by bacterial-specific nitroreductase (NTR) enzymes. NTR enzymes are present in a wide range of bacterial genera and absent in mammalian systems, permitting highly specific detection of Gram-negative and Gram-positive bacteria in vivo. In this study, dose-responsive bacterial-specific signals were observed in vitro from all genera examined - E. coli, Salmonella, Listeria, Bifidobacterium and Clostridium difficile. Examination of an NTR-knockout strain validated the enzyme specificity of the probe. In vivo whole-body imaging permitted specific, dose-responsive monitoring of bacteria over time in various infection models, and no toxicity to bacteria or host was observed. This study demonstrates

  9. Intravaginal metronidazole gel versus metronidazole plus nystatin ovules for bacterial vaginosis: a randomized controlled trial.

    PubMed

    Sanchez, Sixto; Garcia, Patricia J; Thomas, Katherine K; Catlin, Mary; Holmes, King K

    2004-12-01

    We compared metronidazole 0.75% gel (containing 37.5 mg metronidazole per dose) with ovules containing metronidazole 500 mg and nystatin 100,000 U, for intravaginal treatment of bacterial vaginosis (BV). In a single-blinded trial, symptomatic women with BV by both Amsel and Nugent criteria were randomly assigned to gel or ovules, once nightly for 5 nights, and asked to return 3 times after treatment. Analyses were intent-to-treat. Of 151 women with BV by both criteria at enrollment, 138 (91%) returned at least once. Product limit estimates for persistence or recurrence of BV at 14, 42, and 104 days were 20% (95% CI 10%-29%), 38% (95% CI 25%-48%), and 52% (95% CI 37%-63%) after gel treatment, and 4% (95% CI 0%-9%), 17% (95% CI 7%-26%), and 33% (95% CI 21%-46%) after ovule treatment ( P = .01). Among women without BV at first follow-up, subsequent intercourse without condoms independently predicted subsequent recurrence ( P Metronidazole/nystatin ovules were significantly more effective than metronidazole gel. Unprotected sex predicted recurrence after initial improvement.

  10. Metronidazole-induced encephalopathy in a patient with liver cirrhosis

    PubMed Central

    Cheong, Hyeong Cheol; Jeong, Taek Geun; Cho, Young Bum; Yang, Bong Joon; Kim, Tae Hyeon; Kim, Haak Cheoul

    2011-01-01

    Encephalopathy is a disorder characterized by altered brain function, which can be attributed to various causes. Encephalopathy associated with metronidazole administration occurs rarely and depends on the cumulative metronidazole dose, and most patients with this condition recover rapidly after discontinuation of therapy. Because metronidazole is metabolized in the liver and can be transported by the cerebrospinal fluid and cross the blood-brain barrier, it may induce encephalopathy even at a low cumulative dose in patients with hepatic dysfunction. We experienced a patient who showed ataxic gait and dysarthric speech after receiving metronidazole for the treatment of hepatic encephalopathy that was not controlled by the administration of lactulose. The patient was diagnosed as metronidazole-induced encephalopathy, and stopping drug administration resulted in a complete recovery from encephalopathy. This case shows that caution should be exercised when administering metronidazole because even a low dose can induce encephalopathy in patients with liver cirrhosis. PMID:21757988

  11. Interaction of metronidazole with DNA repair mutants of Escherichia coli.

    PubMed Central

    Yeung, T C; Beaulieu, B B; McLafferty, M A; Goldman, P

    1984-01-01

    It has been proposed that one of metronidazole's partially reduced intermediates interacts either with DNA to exert a bactericidal effect or with water to form acetamide. To test this hypothesis we have examined the effect of metronidazole on several mutants of Escherichia coli that are defective in DNA repair. UV-susceptible RecA- and UvrB- point mutants have an increased susceptibility to metronidazole as manifested by both a decreased minimal inhibitory concentration and a greater bactericidal response to metronidazole in resting cultures. By these criteria, however, we find that UvrB- deletion mutants, which lack the ability to reduce nitrate and chlorate, are no more susceptible to metronidazole than is the wild type. We find, however, that these deletion mutants also lack the ability to reduce metronidazole and thus possibly to form its reactive species. When metronidazole's bactericidal effect is expressed in terms of the concurrent accumulation of acetamide derived from metronidazole, then all RecA- and UvrB- mutants are killed more efficiently than their wild types. The data are consistent, therefore, with metronidazole's lethal effect being mediated by a partially reduced intermediate on the metabolic pathway between metronidazole and acetamide. Defects in other aspects of the DNA repair system do not confer this increased susceptibility to the proposed intermediate. A Tag- mutant, for example, which is defective in 3-methyl-adenine-DNA glycosylase, does not have this increased susceptibility to the presumed precursor of acetamide. Thus, these results provide further support for the hypothesis that the bactericidal effect of metronidazole is mediated by a partially reduced intermediate in the metabolic conversion of metronidazole to acetamide and suggest that this intermediate interacts with DNA to produce a lesion similar to that caused by UV light. PMID:6367636

  12. 78 FR 19271 - Draft Guidance for Industry on Bioequivalence Recommendations for Metronidazole Vaginal Gel...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-29

    ... Recommendations for Metronidazole Vaginal Gel; Availability AGENCY: Food and Drug Administration, HHS. ACTION... guidance for industry entitled ``Bioequivalence Recommendations for Metronidazole Vaginal Gel.'' The... abbreviated new drug applications (ANDAs) for metronidazole vaginal gel. DATES: Although you can comment on...

  13. Uptake of metronidazole in Artemia at different developmental life stages.

    PubMed

    Rodriguez, Loretta; Livengood, Elisa J; Miles, Richard D; Chapman, Frank A

    2011-06-01

    The purpose of this study was to examine the capacity of live brine shrimp Artemia spp. to accumulate metronidazole at different developmental life stages. Metronidazole is used in fish as an antiparasitic medication. An effective drug delivery method is to enrich the Artemia with metronidazole and offer them as live feed to the infected fish, usually ornamental species and other small fishes. Artemia cysts were hatched and then soaked in a metronidazole solution (0.05%) at instars 1-3 of larval development. Our findings indicated that Artemia were able to accumulate metronidazole at levels considered therapeutic to other animals and humans (25-100 mg/kg). However, the levels varied depending on the stage of larval development. Artemia accumulated the highest levels of metronidazole (137-143 mg/kg) when they started filter feeding (instar 2), whereas newly hatched Artemia (instar 1) contained the lowest level (85 mg/kg). Based on this study and a review of the literature, a new protocol recommended for enriching Artemia with metronidazole consists of soaking the Artemia in a 0.05% metronidazole solution for 3 h at room temperature. Because metronidazole is relatively insoluble in water, it must first be dissolved in warm water with continuous stirring.

  14. Novel aryl carbamate derivatives of metronidazole as potential antiamoebic agents.

    PubMed

    Hayat, Faisal; Wahedi, Hussain Mustatab; Park, Seonghyeok; Tariq, Saba; Azam, Amir; Shin, Dongyun

    2016-01-01

    A series of novel aryl carbamate derivatives of metronidazole (MNZ) were designed, synthesized, and screened for antiamoebic activity. As compared to MNZ, most of the derivatives exhibited moderate to excellent activity against the HM1:IMSS strain of Entamoeba histolytica. Compounds 7, 14, 16, 19, and 21 exhibited the most promising antiamoebic activity with IC50 values of 0.24, 0.08, 0.26, 0.26, and 0.15 μM, respectively, compared to that of MNZ (1.78 μM). Moreover, from the toxicological studies of these compounds on human melanocytes, the melan-a cell line revealed that the potent compounds are nontoxic at concentrations ranging from 2.5 to 50 μM.

  15. Systemic Metronidazole May Not Reduce Posthemorrhoidectomy Pain: A Meta-Analysis of Randomized Controlled Trials.

    PubMed

    Wanis, Kerollos Nashat; Emmerton-Coughlin, Heather M; Coughlin, Shaun; Foley, Norine; Vinden, Christopher

    2017-04-01

    Hemorrhoidectomy is associated with significant postoperative pain. Oral metronidazole has been recommended as an adjunct to improve posthemorrhoidectomy analgesia. This study aimed to evaluate the impact of oral metronidazole on patient-reported pain following hemorrhoidectomy. We conducted a systematic search in the MEDLINE, EMBASE, ISI Web of Science, and Cochrane Central Register of Controlled Trials databases. Randomized controlled trials examining adults who underwent surgical hemorrhoidectomy were included. Participants in an active intervention group received oral metronidazole postoperatively, and those in a control group received placebo or usual care. Postoperative pain was assessed for at least 3 days postoperatively. A random-effects model was used. The primary outcome was pain during the first 2 postoperative weeks, measured on a visual analogue scale. The secondary outcome was time to return to normal activities. Patients who received oral metronidazole had significantly lower reported pain scores on postoperative day 1 (standardized mean difference, -0.87 ± 0.44; 95% CI, -1.73 to -0.015; p = 0.046; n = 4) and day 4 (standardized mean difference, -1.43 ± 0.71; 95% CI, -2.83 to -0.037; p = 0.044; n = 3). Metronidazole use was associated with a significantly shorter time to return to normal activities (standardized mean difference, -0.76 ± 0.34; 95% CI, -1.43 to -0.088, p = 0.027). The improvements disappeared in a sensitivity analysis excluding the largest trial with a high risk of bias, and no significance was observed during the remaining postoperative days. The meta-analysis was limited by lack of double blinding, absence of a placebo, and unclear or high risk of bias in a proportion of the included trials. Although a favorable adverse effect profile supports consideration of oral metronidazole to reduce posthemorrhoidectomy pain, pooled analysis reveals inconsistent results with no pain reduction on most postoperative days. The

  16. The effect of methylcellulose on metronidazole release from polyacrylic acid hydrogels.

    PubMed

    Musial, Witold

    2007-08-01

    Topical treatment of acne rosacea, a chronic condition characterized by recurrent course for many years, is primarily based on metronidazole preparations. The aim of this study was to evaluate the effect of various acrylic acid polymers, in composition with methylcellulose on metronidazole release rate from hydrogels proposed for the treatment of acne rosacea. Viscosity and release studies using "Paddle over Disk" system with semipermeable membrane of MWCO 3500 were performed. Compositions of Carbopol 971P and methylcellulose revealed an increase in viscosity with increasing concentration of methylcellulose in the range of 17200-26166 mPa.s. In all the examined formulations, the release process was characterized by a two-stage course. Among bipolymeric formulations, the highest first-stage release rate of 9.18 x 10(-3) min(-1) was determined for the gel consisting of 2.00% Carbopol 980NF with 1.00% methylcellulose. The second-stage release rates ranged between 2.88 x 10(-3) and 8.00 x 10(-3) min(-1). Two-stage release course can thus be attributed to metronidazole distribution into two compartments of hydrogel matrix. Proposed gels, with similar rheological properties, may be used for ex vivo and in vivo studies to obtain a suitable drug activity of metronidazole in the treatment of acne rosacea.

  17. Synthesis, molecular docking and biological evaluation of metronidazole derivatives containing piperazine skeleton as potential antibacterial agents.

    PubMed

    Wang, She-Feng; Yin, Yong; Qiao, Fang; Wu, Xun; Sha, Shao; Zhang, Li; Zhu, Hai-Liang

    2014-04-15

    Metronidazole has a broad-spectrum antibacterial activity. Hereby a series of novel metronidazole derivatives were designed and synthesized based on nitroimidazole scaffold in order to find some more potent antibacterial drugs. For these compounds which were reported for the first time, their antibacterial activities against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus were tested. These compounds showed good antibacterial activities against Gram-positive strains. Compound 4m represented the most potent antibacterial activity against S. aureus ATCC 25923 with MIC of 0.003 μg/mL and it showed the most potent activity against S. aureus TyrRS with IC50 of 0.0024 μM. Molecular docking of 4m into S. aureus tyrosyl-tRNA synthetase active site were also performed to determine the probable binding mode.

  18. Chemotherapy of Leishmaniasis.

    DTIC Science & Technology

    1979-09-01

    possess trypanocidal action (nifurti-ox, benznidazole), two metronidazole analogues (LIV/1319 and 1320), and two compounds with activity against...sion1ficantly blocked by certain dihydrofolate reductase inhibitors. A-3 S. *-h.." . "’" V" W2. Nitroreductase-linked pathways. Metronidazole has been shown

  19. Understanding the Broad Substrate Repertoire of Nitroreductase Based on Its Kinetic Mechanism*

    PubMed Central

    Pitsawong, Warintra; Hoben, John P.; Miller, Anne-Frances

    2014-01-01

    The oxygen-insensitive nitroreductase from Enterobacter cloacae (NR) catalyzes two-electron reduction of nitroaromatics to the corresponding nitroso compounds and, subsequently, to hydroxylamine products. NR has an unusually broad substrate repertoire, which may be related to protein dynamics (flexibility) and/or a simple non-selective kinetic mechanism. To investigate the possible role of mechanism in the broad substrate repertoire of NR, the kinetics of oxidation of NR by para-nitrobenzoic acid (p-NBA) were investigated using stopped-flow techniques at 4 °C. The results revealed a hyperbolic dependence on the p-NBA concentration with a limiting rate of 1.90 ± 0.09 s−1, indicating one-step binding before the flavin oxidation step. There is no evidence for a distinct binding step in which specificity might be enforced. The reduction of p-NBA is rate-limiting in steady-state turnover (1.7 ± 0.3 s−1). The pre-steady-state reduction kinetics of NR by NADH indicate that NADH reduces the enzyme with a rate constant of 700 ± 20 s−1 and a dissociation constant of 0.51 ± 0.04 mm. Thus, we demonstrate simple transient kinetics in both the reductive and oxidative half-reactions that help to explain the broad substrate repertoire of NR. Finally, we tested the ability of NR to reduce para-hydroxylaminobenzoic acid, demonstrating that the corresponding amine does not accumulate to significant levels even under anaerobic conditions. Thus E. cloacae NR is not a good candidate for enzymatic production of aromatic amines. PMID:24706760

  20. Bioremediation of 2,4,6-trinitrotoluene by bacterial nitroreductase expressing transgenic aspen.

    PubMed

    Van Dillewijn, Pieter; Couselo, José L; Corredoira, Elena; Delgado, Antonio; Wittich, Rolf-Michael; Ballester, Antonio; Ramos, Juan L

    2008-10-01

    Trees belonging to the genus Populus are often used for phytoremediation due to their deep root formation, fast growth and high transpiration rates. Here, we study the capacity of transgenic hybrid aspen (Populus tremula x tremuloides var. Etropole) which expresses the bacterial nitroreductase gene, pnrA, to tolerate and take-up greater amounts of the toxic and recalcitrant explosive, 2,4,6-trinitrotoluene (TNT) from contaminated waters and soil. Transgenic aspen tolerate up to 57 mg TNT/L in hydroponic media and more than 1000 mg TNT/ kg soil, whereas the parental aspen could not endure in hydroponic culture with more than 11 mg TNT/L or soil with more than 500 mg TNT/kg. Likewise, the phytotoxicological limit for transgenic plants to a constant concentration of TNT was 20 mg TNT/L while wild-type plants only tolerated 10 mg TNT/L. Transgenic plants also showed improved uptake of TNT over wild-type plants when the original TNT concentration was above 35 mg TNT/L in liquid media or 750 mg TNT/kg in soil. Assays with 13C-labeled TNT show rapid adsorption of TNT to the root surface followed by a slower entrance rate into the plant. Most of the 13C-carbon from the labeled TNT taken up bythe plant (> 95%) remains in the root with little translocation to the stem. Altogether, transgenic aspen expressing pnrA are highly interesting for phytoremediation applications on contaminated soil and underground aquifers.

  1. Metronidazole-induced encephalopathy in a patient with Crohn's disease

    PubMed Central

    Kim, Jihye; Park, Jae Yong; Hong, Seung Wook; Lee, Joo Young; Kang, Jin Woo; Hwang, Seongjun; Ko, Sang-Bae; Im, Jong Pil; Kim, Joo Sung

    2017-01-01

    Metronidazole is a widely used antibiotic for the treatment of anaerobic bacterial infections. Metronidazole-induced encephalopathy (MIEP) is a rare but potentially reversible disease. The mechanism of MIEP remains unclear, and differences in the neurotoxic effects of oral versus intravenous (IV) metronidazole administration have not yet been determined. We report the case of a Crohn's disease (CD) patient who experienced encephalopathy immediately after a single IV dose of metronidazole following long-term exposure to the oral form of the drug. The 64-year-old man with intractable CD experienced a sudden change in mental status, aphasia, and muscle weakness after IV administration of metronidazole. He had previously taken metronidazole orally for 13 years and received intermittent IV metronidazole treatments for CD exacerbation. Brain magnetic resonance imaging (MRI) showed high-intensity signals in the bilateral medial thalamus and the midbrain and pontine tegmentum on fluid-attenuated inversion recovery images. After discontinuation of metronidazole, the high-intensity brain MRI signals resolved and the patient's mental status dramatically improved; however, the patient exhibited mild cognitive dysfunction 2 months after the onset of encephalopathy. PMID:28239323

  2. Preparation and Cyclodextrin Solubilization of the Antibacterial Agent Benzoyl Metronidazole

    PubMed Central

    Yang, Shuo

    2013-01-01

    A one-pot method for the preparation of benzoyl metronidazole was achieved by using N,N′-carbonyldiimidazole as a coupling reagent. Moreover, it was found that the byproduct imidazole as the catalyst promoted the reaction. In addition, the β-cyclodextrin solubilization of benzoyl metronidazole was investigated by phase-solubility method. The phase-solubility studies indicated that the solubility of benzoyl metronidazole (S = 0.1435 g/L) was substantially increased 9.7-fold (S′ = 1.3881 g/L) by formation of 1 : 1 benzoyl metronidazole/β-cyclodextrin complexes in water, and the association constant K a value was determined to be 251 (±23) dm3/mol. Therefore, β-cyclodextrin can work as a pharmaceutical solubilizer for benzoyl metronidazole and may improve its oral bioavailability. PMID:23970831

  3. [Reversible neurotoxicity secondary to metronidazole: report of one case].

    PubMed

    Retamal-Riquelme, Eva; Soto-San Martín, Hernán; Vallejos-Castro, José; Galdames-Poblete, Daniel

    2014-03-01

    Metronidazole can cause adverse effects both in the central and peripheral nervous system. We report a 34-year-old female who presented a reversible cerebellar syndrome and peripheral neuropathy as an adverse effect associated with the use of metronidazole. Brain magnetic resonance imaging (MRI) showed hyperintense T2 and FLAIR bilateral symmetrical cerebellar lesions, without contrast enhancement or mass effect, isointense in diffusion-weighted imaging and hypointense in apparent diffusion coefficient sequences. Also, electrophysiological evaluation was consistent with axonal polyneuropathy. She had received metronidazole for a liver abscess during 49 days. After discontinuation of metronidazole, she had rapid regression of cerebellar symptoms and normalization of MRI, with subsequent disappearance of peripheral symptoms. The brain MRI, electromyography and nerve conduction studies performed at 35 months later showed complete resolution of the lesions. Although metronidazole neurotoxicity is a rare event, it must be borne in mind because the prognosis is usually favorable after stopping the drug.

  4. Pharmacokinetics of metronidazole in pregnant patients with bacterial vaginosis.

    PubMed

    Wang, Xin; Nanovskaya, Tatiana N; Zhan, Ying; Abdel-Rahman, Susan M; Jasek, Marlo; Hankins, Gary D V; Ahmed, Mahmoud S

    2011-03-01

    The present study was undertaken to investigate the pharmacokinetics of metronidazole in pregnant patients with bacterial vaginosis. Twenty patients received metronidazole (Flagyl ®, Pfizer, 235 East 42nd Street, NY, NY 10017) oral dose 500 mg twice a day for 3 consecutive days. Pharmacokinetic analyses of metronidazole were performed after a single oral dose on the morning of day 4. Although absolute estimates of metronidazole total body exposure were highest in women during early term pregnancy, weight-corrected estimates of exposure maximum plasma drug concentration (C(max)) and the area under the plasma concentration-versus-time curve (AUC(0-12)), along with apparent oral clearance and distribution volume, were not significantly different between women at early, middle, and late stages of pregnancy and were in the range of reported values for nonpregnant patients receiving a similar dose. The pharmacokinetic profile of metronidazole did not change at the different time points assessed during pregnancy.

  5. Pharmacokinetics of metronidazole in pregnant patients with bacterial vaginosis

    PubMed Central

    Wang, Xin; Nanovskaya, Tatiana N.; Zhan, Ying; Abdel-Rahman, Susan M.; Jasek, Marlo; Hankins, Gary D.V.; Ahmed, Mahmoud S.

    2010-01-01

    Objective The present study was undertaken to investigate the pharmacokinetics of metronidazole in pregnant patients with bacterial vaginosis. Methods Twenty patients received metronidazole (Flagyl,® Pfizer, 235 East 42nd Street, NY, NY 10017) oral dose 500 mg twice a day for 3 consecutive days. Pharmacokinetic analyses of metronidazole were performed after a single oral dose on the morning of the day 4. Results Although absolute estimates of metronidazole total body exposure were highest in women during early term pregnancy, weight-corrected estimates of exposure maximum plasma drug concentration (Cmax, ) and the area under the plasma concentration-versus-time curve (AUC0-12), along with apparent oral clearance and distribution volume, were not significantly different between women at early, middle, and late stages of pregnancy and were in the range of reported values for nonpregnant patients receiving a similar dose. Conclusions The pharmacokinetic profile of metronidazole did not change at the different time points assessed during pregnancy. PMID:20608802

  6. Gastrointestinal localization of metronidazole by a lactobacilli-inspired tetramic acid motif improves treatment outcomes in the hamster model of Clostridium difficile infection

    PubMed Central

    Cherian, Philip T.; Wu, Xiaoqian; Yang, Lei; Scarborough, Jerrod S.; Singh, Aman P.; Alam, Zahidul A.; Lee, Richard E.; Hurdle, Julian G.

    2015-01-01

    Objectives Metronidazole, a mainstay treatment for Clostridium difficile infection (CDI), is often ineffective for severe CDI. Whilst this is thought to arise from suboptimal levels of metronidazole in the colon due to rapid absorption, empirical validation is lacking. In contrast, reutericyclin, an antibacterial tetramic acid from Lactobacillus reuteri, concentrates in the gastrointestinal tract. In this study, we modified metronidazole with reutericyclin's tetramic acid motif to obtain non-absorbed compounds, enabling assessment of the impact of pharmacokinetics on treatment outcomes. Methods A series of metronidazole-bearing tetramic acid substituents were synthesized and evaluated in terms of anti-C. difficile activities, gastric permeability, in vivo pharmacokinetics, efficacy in the hamster model of CDI and mode of action. Results Most compounds were absorbed less than metronidazole in cell-based Caco-2 permeability assays. In hamsters, lead compounds compartmentalized in the colon rather than the bloodstream with negligible levels detected in the blood, in direct contrast with metronidazole, which was rapidly absorbed into the blood and was undetectable in caecum. Accordingly, four leads were more efficacious (P < 0.05) than metronidazole in C. difficile-infected animals. Improved efficacy was not due to an alternative mode of action, as the leads retained the mode of action of metronidazole. Conclusions This study provides the clearest empirical evidence that the high absorption of metronidazole lowers treatment outcomes for CDI and suggests a role for the tetramic acid motif for colon-specific drug delivery. This approach also has the potential to lower systemic toxicity and drug interactions of nitroheterocyclic drugs for treating gastrointestine-specific diseases. PMID:26286574

  7. Gastrointestinal localization of metronidazole by a lactobacilli-inspired tetramic acid motif improves treatment outcomes in the hamster model of Clostridium difficile infection.

    PubMed

    Cherian, Philip T; Wu, Xiaoqian; Yang, Lei; Scarborough, Jerrod S; Singh, Aman P; Alam, Zahidul A; Lee, Richard E; Hurdle, Julian G

    2015-11-01

    Metronidazole, a mainstay treatment for Clostridium difficile infection (CDI), is often ineffective for severe CDI. Whilst this is thought to arise from suboptimal levels of metronidazole in the colon due to rapid absorption, empirical validation is lacking. In contrast, reutericyclin, an antibacterial tetramic acid from Lactobacillus reuteri, concentrates in the gastrointestinal tract. In this study, we modified metronidazole with reutericyclin's tetramic acid motif to obtain non-absorbed compounds, enabling assessment of the impact of pharmacokinetics on treatment outcomes. A series of metronidazole-bearing tetramic acid substituents were synthesized and evaluated in terms of anti-C. difficile activities, gastric permeability, in vivo pharmacokinetics, efficacy in the hamster model of CDI and mode of action. Most compounds were absorbed less than metronidazole in cell-based Caco-2 permeability assays. In hamsters, lead compounds compartmentalized in the colon rather than the bloodstream with negligible levels detected in the blood, in direct contrast with metronidazole, which was rapidly absorbed into the blood and was undetectable in caecum. Accordingly, four leads were more efficacious (P < 0.05) than metronidazole in C. difficile-infected animals. Improved efficacy was not due to an alternative mode of action, as the leads retained the mode of action of metronidazole. This study provides the clearest empirical evidence that the high absorption of metronidazole lowers treatment outcomes for CDI and suggests a role for the tetramic acid motif for colon-specific drug delivery. This approach also has the potential to lower systemic toxicity and drug interactions of nitroheterocyclic drugs for treating gastrointestine-specific diseases. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  8. Mutagenicities of 2,4- and 2,6-dinitrotoluenes and their reduced products in Salmonella typhimurium nitroreductase- and O-acetyltransferase-overproducing Ames test strains.

    PubMed

    Sayama, M; Mori, M; Shoji, M; Uda, S; Kakikawa, M; Kondo, T; Kodaira, K I

    1998-12-03

    Mutagenicities of 2,4- and 2,6-dinitrotoluene (2,4-and 2,6-DNT), and reduced metabolites formed by the incubation of 2,4- and 2,6-DNT with Salmonella typhimurium TA98, were tested using S. typhimurium YG strains possessing high level of nitroreductase (NR) and/or O-acetyltransferase (OAT) activities. All compounds tested showed greatest mutagenic activities toward strains YG1041 and YG1042, which possess high levels of NR and OAT activities. The relative mutagenic activities of 2,4-DNT and its related compounds toward YG1041 and YG1042 were aminonitrotoluenes<2,4-DNT<2,2'-dimethyl-5, 5'-dinitroazoxybenzene (2,2'-DM-5, 5'-DNAOB)4-hydroxylamino-2-nitrotoluene (4HA2NT)<4, 4'-dimethyl-3,3'-dinitroazoxybenzene (4,4'-DM-3,3'-DNAOB), and aminonitrotoluenes (2A4AT, 4A2NT)<2,4-DNT<4HA2NT4,4'-dimethyl-3, 3'-dinitroazoxybenzene (4,4'-DM-3,3'-DNAOB)<2HA4NT, respectively. In addition, the relative mutagenic activities of 2,6-DNT and its related compounds toward YG1041 and YG1042 were 2, 6-DNT<2-hydroxylamino-6-nitrotoluene (2HA6NT)<2,2'-dimethyl-3, 3'-dinitroazoxybenzene (2,2'-DM-3,3'-DNAOB), and 2-amino-6-nitrotoluene (2A6NT)<2,6-DNT<2HA6NT, respectively. These results, together with previous findings, suggested that aminohydroxylamino dimethylazoxybenzenes or aminohydroxylamino dimethylazobenzenes produced either by the reduction of hydroxylaminonitrotoluenes or by the reduction of dimethyl dinitroazoxybenzenes are active metabolites responsible for the mutagenic activities of 2,4- and 2,6-DNT.

  9. Cumulative irritation potential among metronidazole gel 1%, metronidazole gel 0.75%, and azelaic acid gel 15%.

    PubMed

    Colón, Luz E; Johnson, Lori A; Gottschalk, Ronald W

    2007-04-01

    Topical therapy for rosacea aims to reduce inflammatory lesions and decrease erythema but can carry side effects such as stinging, pruritus, and burning. Metronidazole and azelaic acid gel 15% are U.S. Food and Drug Administration-approved for the treatment of rosacea. The current study was conducted to assess the cumulative irritation potential of 2 formulations of metronidazole 0.75% gel and 1% gel--and azelaic acid gel 15% over 21 days (N=36). Results of this study demonstrated a significantly greater poten tial for irritation from azelaic acid compared with metronidazole gel 0.75% (P < .0001), which had significantly greater potential for irritation compared with metronidazole gel 1% (P = .0054). Metronidazole gel 1% had a similar profile to white petrolatum.

  10. The use of metronidazole during pregnancy: a review of evidence.

    PubMed

    Sheehy, Odile; Santos, Fabiano; Ferreira, Ema; Berard, Anick

    2015-01-01

    To review the available evidence concerning the relationship between the exposure to metronidazole during pregnancy and the risk of preterm delivery and birth defects. Studies investigating the association between gestational use of oral metronidazole on human subjects and the risk of preterm birth or/and birth defects were systematically retrieved from MEDLINE and EMBASE databases. We selected studies published in English or French between 1964 and 2012. Where effect estimates were not reported, crude ORs along with 95% confidence intervals were calculated. We selected 17 studies investigating the association between exposure to oral metronidazole and the risk of preterm birth, from which 12 were randomized clinical trials. In addition, we identified 13 studies devoted to the relationship between metronidazole and birth defects, from which 10 were cohort studies, 1 was a case-control study and 2 were meta-analysis. During pregnancy, treating bacterial vaginosis and trichomoniasis with metronidazole is effective and offers no teratogen risk. Benefit of metronidazole in the reduction of preterm birth was demonstrated for the combination of this medication with other antibiotics. Additional information is needed when metronidazole is used in association with other agents.

  11. Metronidazole with Lactacyd vaginal gel in bacterial vaginosis.

    PubMed

    Decena, Ditas Cristina D; Co, Jennifer T; Manalastas, Ricardo M; Palaypayon, Evelyn P; Padolina, Christia S; Sison, Judith M; Dancel, Louella A; Lelis, Marievi A

    2006-04-01

    To assess the efficacy and tolerability of lactic acid (Lactacyd vaginal gel; LVG) when given as an adjunct to metronidazole in the treatment of bacterial vaginosis (BV) among Filipino patients. A multicenter, open-labeled, controlled, randomized, three-arm comparative study on 90 women aged 18 years or over with clinically and microbiologically proven BV. The lactobacilli colony count significantly increased over time in all three arms. At day 14, growth of lactobacilli was significantly higher among patients in the lactic acid gel and combination treatment arms. Significant reduction of malodorous vaginal discharge (whiff test) and lowest recurrence of BV were noted in the metronidazole plus lactic acid gel arm. Regarding disappearance of signs of BV, there was significant decrease in the pH level and frequency of clue cell positive patients across time but was not significantly different across treatment groups. Only one patient (3%, 1/60) among those who received lactic acid gel complained of increased curd-like discharge. Six patients (10%, 6/60) who received metronidazole complained of epigastric pain/discomfort, dizziness and dyspnea. Lactic acid gel (LVG) is safe and as efficacious as metronidazole in the treatment of BV. There is evidence that LVG when combined with metronidazole is superior to metronidazole alone in promoting lactobacilli colonization. LVG as an adjunct to metronidazole, having the least number of recurrent BV, appears to result in better long-term treatment effect on bacterial vaginosis.

  12. 2-nitrobenzoate 2-nitroreductase (NbaA) switches its substrate specificity from 2-nitrobenzoic acid to 2,4-dinitrobenzoic acid under oxidizing conditions.

    PubMed

    Kim, Yong-Hak; Song, Woo-Seok; Go, Hayoung; Cha, Chang-Jun; Lee, Cheolju; Yu, Myeong-Hee; Lau, Peter C K; Lee, Kangseok

    2013-01-01

    2-Nitrobenzoate 2-nitroreductase (NbaA) of Pseudomonas fluorescens strain KU-7 is a unique enzyme, transforming 2-nitrobenzoic acid (2-NBA) and 2,4-dinitrobenzoic acid (2,4-DNBA) to the 2-hydroxylamine compounds. Sequence comparison reveals that NbaA contains a conserved cysteine residue at position 141 and two variable regions at amino acids 65 to 74 and 193 to 216. The truncated mutant Δ65-74 exhibited markedly reduced activity toward 2,4-DNBA, but its 2-NBA reduction activity was unaffected; however, both activities were abolished in the Δ193-216 mutant, suggesting that these regions are necessary for the catalysis and specificity of NbaA. NbaA showed different lag times for the reduction of 2-NBA and 2,4-DNBA with NADPH, and the reduction of 2,4-DNBA, but not 2-NBA, failed in the presence of 1 mM dithiothreitol or under anaerobic conditions, indicating oxidative modification of the enzyme for 2,4-DNBA. The enzyme was irreversibly inhibited by 5,5'-dithio-bis-(2-nitrobenzoic acid) and ZnCl(2), which bind to reactive thiol/thiolate groups, and was eventually inactivated during the formation of higher-order oligomers at high pH, high temperature, or in the presence of H(2)O(2). SDS-PAGE and mass spectrometry revealed the formation of intermolecular disulfide bonds by involvement of the two cysteines at positions 141 and 194. Site-directed mutagenesis indicated that the cysteines at positions 39, 103, 141, and 194 played a role in changing the enzyme activity and specificity toward 2-NBA and 2,4-DNBA. This study suggests that oxidative modifications of NbaA are responsible for the differential specificity for the two substrates and further enzyme inactivation through the formation of disulfide bonds under oxidizing conditions.

  13. 2-Nitrobenzoate 2-Nitroreductase (NbaA) Switches Its Substrate Specificity from 2-Nitrobenzoic Acid to 2,4-Dinitrobenzoic Acid under Oxidizing Conditions

    PubMed Central

    Song, Woo-Seok; Go, Hayoung; Cha, Chang-Jun; Lee, Cheolju; Yu, Myeong-Hee; Lau, Peter C. K.

    2013-01-01

    2-Nitrobenzoate 2-nitroreductase (NbaA) of Pseudomonas fluorescens strain KU-7 is a unique enzyme, transforming 2-nitrobenzoic acid (2-NBA) and 2,4-dinitrobenzoic acid (2,4-DNBA) to the 2-hydroxylamine compounds. Sequence comparison reveals that NbaA contains a conserved cysteine residue at position 141 and two variable regions at amino acids 65 to 74 and 193 to 216. The truncated mutant Δ65-74 exhibited markedly reduced activity toward 2,4-DNBA, but its 2-NBA reduction activity was unaffected; however, both activities were abolished in the Δ193-216 mutant, suggesting that these regions are necessary for the catalysis and specificity of NbaA. NbaA showed different lag times for the reduction of 2-NBA and 2,4-DNBA with NADPH, and the reduction of 2,4-DNBA, but not 2-NBA, failed in the presence of 1 mM dithiothreitol or under anaerobic conditions, indicating oxidative modification of the enzyme for 2,4-DNBA. The enzyme was irreversibly inhibited by 5,5′-dithio-bis-(2-nitrobenzoic acid) and ZnCl2, which bind to reactive thiol/thiolate groups, and was eventually inactivated during the formation of higher-order oligomers at high pH, high temperature, or in the presence of H2O2. SDS-PAGE and mass spectrometry revealed the formation of intermolecular disulfide bonds by involvement of the two cysteines at positions 141 and 194. Site-directed mutagenesis indicated that the cysteines at positions 39, 103, 141, and 194 played a role in changing the enzyme activity and specificity toward 2-NBA and 2,4-DNBA. This study suggests that oxidative modifications of NbaA are responsible for the differential specificity for the two substrates and further enzyme inactivation through the formation of disulfide bonds under oxidizing conditions. PMID:23123905

  14. Non-destructive determination of metronidazole powder by using artificial neural networks on short-wavelength NIR spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhao, Lingzhi; Dou, Ying; Mi, Hong; Ren, Meiyan; Ren, Yulin

    2007-04-01

    The present study aimed at providing a new method in sight into short-wavelength near-infrared (NIR) spectroscopy of in pharmaceutical quantitative analysis. To do that, 124 experimental samples of metronidazole powder were analyzed using artificial neural networks (ANNs) in the 780-1100 nm region of short-wavelength NIR spectra. In this paper, metronidazole was as active component and other two components (magnesium stearate and starch) were as excipients. Different preprocessing spectral data (first-derivative, second-derivative, standard normal variate (SNV) and multiplicative scatter correction (MSC)) were applied to establish the ANNs models of metronidazole powder. The degree of approximation, a new evaluation criterion of the networks was employed to prove the accuracy of the predicted results. The results presented here demonstrate that the short-wavelength NIR region is promising for the fast and reliable determination of major component in pharmaceutical analysis.

  15. A rare adverse effect of metronidazole: nervous system symptoms.

    PubMed

    Kafadar, Ihsan; Moustafa, Fatma; Yalçın, Koray; Klç, Betül Aydn

    2013-06-01

    Metronidazole, as a 5-nitroimidazole compound, is effective on anaerobic bacteria and protozoon diseases. Mostly, metronidazole is a tolerable drug but rarely presents serious adverse effects on the nervous system. In case of these adverse effects, treatment must be stopped.In this report, a 3-year-old child hospitalized because of diarrhea is presented. During the metronidazole treatment, loss of sight, vertigo, ataxia, and headache occurred as the adverse effects. By this report, we want to express the rare adverse effects of drugs in the differential diagnoses of nervous system diseases.

  16. DNA breakage due to metronidazole treatment.

    PubMed

    Menéndez, D; Rojas, E; Herrera, L A; López, M C; Sordo, M; Elizondo, G; Ostrosky-Wegman, P

    2001-07-01

    The mutagenicity of metronidazole [1-(hidroxyethyl)-2-methyl-5-nitroimidazole] (MTZ) has been shown in different prokaryotic systems. However, data on human cells are still contradictory. In this study DNA damage was determined by the single cell gel electrophoresis (SCGE) assay, in lymphocytes from 10 healthy subjects treated with therapeutic doses of this drug. Samples were obtained before treatment, as well as 1 and 15 days after ending treatment. Results showed a significant increase of DNA strand breaks 1 day after ending treatment, although, an inverse correlation between the amount of DNA damage and plasma concentrations of MTZ was obtained. Thus, the observed damage may be induced by some MTZ metabolite rather than by the parent drug. Interestingly, the amount of DNA damage returned to basal levels 15 days after ending treatment, except in two individuals. This persistent damage should be further investigated.

  17. Vulvoperineal Crohn's disease responsive to metronidazole*

    PubMed Central

    Rosmaninho, Aristóteles; Sanches, Madalena; Salgado, Marta; Alves, Rosário; Selores, Manuela

    2013-01-01

    Crohn's disease is a multisystem chronic granulomatous inflammatory disease that primarily affects the gastrointestinal tract. In the majority of the cases, the cutaneous manifestations follow the intestinal disease, but occasionally dermatological lesions are the inaugural event and may constitute the only sign of the disease. Vulvoperineal involvement is rare, may precede bowel symptoms by months to years and may go unrecognized. Due to the paucity of reports of Crohn's disease at this location and in the absence of randomized trials, there are no standard treatments for the cutaneous disease. We describe the case of a 47 year-old woman with vulvoperineal Crohn's disease without digestive involvement, that was successfully managed with metronidazole. PMID:24346884

  18. Novel metronidazole-chalcone conjugates with potential to counter drug resistance in Trichomonas vaginalis.

    PubMed

    Anthwal, Amit; Rajesh, U Chinna; Rawat, M S M; Kushwaha, Bhavana; Maikhuri, Jagdamba P; Sharma, Vishnu L; Gupta, Gopal; Rawat, Diwan S

    2014-05-22

    Trichomoniasis is the most prevalent, curable sexually transmitted disease (STD), which increases risk of viral STDs and HIV. However, drug resistance has been developed by some strains of Trichomonas vaginalis against Metronidazole (MTZ), the FDA approved drug against trichomoniasis. In the present study twenty two chalcone hybrids of metronidazole have been synthesized in a quest to get new molecules with higher potential against metronidazole-resistant T. vaginalis. All new hybrid molecules were found active against T. vaginalis with varying levels of activity against MTZ-susceptible and resistant strains. Eight compounds (4a, 4c, 4d, 4e, 4f, 4h, 4q and 4s) were found as active as the standard drug with an MIC of 1.56 μg/ml against MTZ-susceptible strain. However, compounds 4e, 4h and 4m were 4-times more active than MTZ against drug-resistant T. vaginalis, amongst which 4e and 4h were most promising against both susceptible and resistant strains.

  19. Metronidazole as a protector of cells from electromagnetic radiation of extremely high frequencies

    NASA Astrophysics Data System (ADS)

    Kuznetsov, Pavel E.; Malinina, Ulia A.; Popyhova, Era B.; Rogacheva, Svetlana M.; Somov, Alexander U.

    2006-08-01

    It is well known that weak electromagnetic fields of extremely high frequencies cause significant modification of the functional status of biological objects of different levels of organization. The aim of the work was to study the combinatory effect of metronidazole - the drug form of 1-(2'hydroxiethil)-2-methil-5-nitroimidazole - and electromagnetic radiation of extremely high frequencies (52...75 GHz) on the hemolytic stability of erythrocytes and hemotaxis activity of Infusoria Paramecium caudatum.

  20. Synthesis of New Nitrofluoroquinolone Derivatives with Novel Anti-Microbial Properties against Metronidazole Resistant H. pylori.

    PubMed

    Abu-Qatouseh, Luay; Abu-Sini, Mohammad; Mayyas, Amal; Al-Hiari, Yusuf; Darwish, Rula; Aburjai, Talal

    2017-01-04

    One of the major therapeutic approaches to preventing relapse and accelerating the healing of duodenal and gastric ulcers is the eradication of Helicobacter pylori. Due to the emergence of antibiotic resistance among clinical strains of H. pylori, alternative approaches using newly discovered antimicrobial agents in combination with the standard regimens for the treatment of H. pylori are increasingly needed. The purpose of the present study was to investigate the effect of newly synthesized 8-nitroflouroqunolone derivatives when used either alone or when combined with metronidazole against metronidazole-resistant H. pylori. Based on the standard antimicrobial susceptibility testing methods and checkerboard titration assay, all of the tested compounds showed interesting antimicrobial activity against 12 clinical strains of H. pylori, with the best in vitro effect for compound 3c. In addition, synergistic and additive activities of some of the tested compounds were observed when combined with metronidazole. Furthermore, among the tested nitroflouroquinolone derivatives, compound 3b showed significant urease inhibition activity with IC50 of 62.5 µg/mL. These results suggest that 8-nitroflouroquinolone derivatives may have a useful role in combination with anti-H. pylori drugs in the management of H. pylori-associated diseases.

  1. [Topical treatment of vaginal infections by the association of metronidazole-clotrimazole].

    PubMed

    Tavassoli, K; Mattana, P

    2013-12-01

    Vaginal infections are one of the most gynecological frequently diseases observed and with significant psychological and clinical implications. Their pharmacological treatment may require different options, but even today, scientific literature and international guidelines recommend the use of metronidazole for the treatment of bacterial vaginosis (BV) and trichomoniasis, and the clotrimazole for fungal infections from Candida (VVC). In this contest, the topical association of clotrimazole-metronidazole (vaginal pessaries, cream and douches) represents a current reference treatment for these types of infections with a number of important pharmacological properties. This combination allows an effective activity against to a broad spectrum of pathogens (bacterial, fungal and protozoan), a feature particularly relevant in the case of mixed infections. Furthermore it allows a synergistic action that improve the therapeutic abilities of the individual components, a reduction of the spontaneous resistance of some microorganisms and the activity against symptoms and signs of vaginal inflammation with maintaining the vaginal ecosystem, since they have no activity against endogenous lactobacilli. Finally, recent studies have shown the ability of the topical association of metronidazole-clotrimazole to inhibit the in vitro phenotypic switching of Candida albicans, and its effectiveness against Recurrent Vulvovaginal Candidiasis (RVVC).

  2. [Susceptibility of potential periodontopathic bacteria to metronidazole, spiramycin and their combination].

    PubMed

    Mouton, C; Dextraze, L; Mayrand, D

    1984-03-01

    A total of 65 bacterial strains originating mostly from subgingival plaque were tested for their susceptibilities to metronidazole, spiramycin, and their combination, ornidazole, erythromycin and tetracycline by means of an agar dilution technique. All agents were active against all anaerobic Gram-negative rods. Bacteroides gingivalis and Fusobacterium nucleatum showed marked susceptibility to metronidazole (MIC less than or equal to 0.06 microgram/ml) whereas 4-64 micrograms/ml were required to inhibit the capnophilic Actinobacillus actinomycetemcomitans and Capnocytophaga. Gram-positive facultatives were resistant to nitro-imidazoles but were inhibited at macrolide concentrations less than or equal to 0.5 microgram/ml. Except for F. nucleatum and Veillonella strains (2 less than or equal to MIC less than or equal to 128 micrograms/ml) macrolides were active against all other anaerobic bacteria tested. At concentrations less than or equal to 2 micrograms/ml the combination of spiramycin and metronidazole (2 : 1) was active against virtually all bacteria tested but our results failed to show a synergistic effect.

  3. [In vitro susceptibility of Trichomonas vaginalis to metronidazole, ornidazole and proton pump inhibitors pantoprazole and esomeprazole].

    PubMed

    Aksoy Gökmen, Ayşegül; Girginkardeşler, Nogay; Kilimcioğlu, Ali Ahmet; Şirin, Mümtaz Cem; Özbilgin, Ahmet

    2016-01-01

    The current treatment of trichomoniasis is based on the use of 5-nitroimidazole derivatives. Although metronidazole is reliable, inexpensive and highly effective against anaerobic microorganisms and protozoa, the development of metronidazole-resistant T.vaginalis strains pose to an increasing problem. Nitroimidazoles are compounds having azomycin (2-nitroimidazole) chemical structure and are obtained from Streptomyces strains. Benzimidazole, which is found in the structure of proton pump inhibitors, is also present in the other components that have antiprotozoal activity. In this study, the in vitro susceptibility of T.vaginalis against metronidazole, ornidazole, and the proton pump inhibitors which are tested recently as antiprotozoal agents; pantoprazole and esomeprazole was investigated. For this purpose a clinical T.vaginalis strain which was formerly isolated and stored after cryopreservation process in our laboratory was used. Minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) values of those agents against to this strain were determined in vitro by dilution method in 24-well cell culture plates. Trypticase yeast extract maltose medium, horse serum and antibiotic (penicillin + streptomycin) were distributed to each well of cell culture plates and after metronidazole, ornidazole, pantoprazole and esomeprazole solutions were added to two wells for each as 800, 400, 200, 100, 50 and 25 µg/ml, followed by the addition of 1 ml 5x10(3) T.vaginalis trophozoites into each well. Plates were incubated at 37°C, and viability and motility of the trophozoites were evaluated under light microscope at 24, 48 and 72 hours after incubation. MIC and MLC values of metronidazole/ornidazole in the 72(th) hour were found as 50 µg/ml and 100 µg/ml, respectively. MIC and MLC values for pantoprazole in the 72th hour were 200 µg/ml and 400 µg/ml, while the values for esomeprazole were 400 µg/ml ve 800 µg/ml, respectively. As a result, T

  4. Metronidazole Toxicity in Cockayne Syndrome: A Case Series.

    PubMed

    Wilson, Brian T; Strong, Andrew; O'Kelly, Sean; Munkley, Jennifer; Stark, Zornitza

    2015-09-01

    Cockayne syndrome (CS) is a rare genetic disorder characterized by small stature, intellectual disability, and accelerated pathologic aging. Through the Cockayne Syndrome Natural History Study, we have identified 8 cases of acute hepatic failure after metronidazole administration (8% of our cohort), 3 of which were fatal. The interval between initial administration and death was 6 to 11 days. Two of these patients also experienced acute neurologic deficit. Both hepatotoxicity and acute neurologic deficit have been reported previously as extremely rare adverse events after metronidazole administration. However, we have not identified any patients with CS who have received metronidazole without serious adverse effects. We recommend that a diagnosis of CS be considered an absolute contraindication to the use of metronidazole.

  5. Tinidazole versus Metronidazole for the Treatment of Bacterial Vaginosis

    PubMed Central

    SCHWEBKE, Jane R.; DESMOND, Renee A.

    2010-01-01

    Objective To compare the efficacy of two different doses of tinidazole with metronidazole for treatment of bacterial vaginosis and compare side effects of the drugs. Study design Women were randomized to metronidazole 500 mg BID, tinidazole 500 mg BID, or tinidazole 1 gm BID all for 7 days. Follow-up visits were conducted at day 14 and day 28. Results 593 women were enrolled. There were no significant differences between the treatment arms. Overall cure rates were 76.8% at 14 days and 64.5% at one month. Women who admitted to engaging in sexual intercourse during the study were significantly more likely to have BV at follow-up. There were no significant differences in adverse events across treatment arms. Conclusions There were no differences in cure rates between metronidazole and either of the tinidazole dosing regimens studied. In addition, there were no important differences in the side effect profiles of metronidazole and tinidazole. PMID:21167471

  6. Seven-Day Bismuth-based Quadruple Therapy as an Initial Treatment for Helicobacter pylori Infection in a High Metronidazole Resistant Area.

    PubMed

    Vilaichone, Ratha-korn; Prapitpaiboon, Hatainuch; Gamnarai, Pornpen; Namtanee, Juraiwan; Wongcha-um, Arti; Chaithongrat, Supakarn; Mahachai, Varocha

    2015-01-01

    The prevalence of metronidazole-resistant H. pylori is almost 50% in Thailand which severely limits the use of this drug for eradication therapy. The aims of this study were to evaluate the efficacy and safety profiles of 7-day bismuth-based quadruple therapy including metronidazole as an initial treatment for H. pylori infection in a high metronidazole resistance area. This study was performed at Thammasat University Hospital and King Chulalongkorn Memorial Hospital during January 2009 to October 2010. Patients with non-ulcer dyspepsia (NUD) with active H. pylori infection were assigned to receive seven days of quadruple therapy (pantoprazole 40 mg bid, bismuth subsalicylate 1,048 mg bid, amoxicillin 1 gm bid and metronidazole 400 mg tid). H. pylori infection was defined as positive H. pylori culture or two positive tests (rapid urease test and histology). Antibiotic susceptibility test for metronidazole by Epsilometer test (E-test) was performed in all positive cultures. At least four weeks after treatment, 13C urea breath test (13C-UBT) was performed to confirm H. pylori eradication. A total of 114 patients were enrolled in this study, 50 males and 64 females with a mean age of 49.8 years. All 114 patients had a diagnosis of NUD. Overall eradication as confirmed by negative 13C-UBT was achieved in 94 out of 114 patients (82.5%). 44 patients had positive cultures and success for E-test. In vitro metronidazole resistance was observed in 22/44 (50%) patients. Eradication rate in patients with metronidazole resistant strains was 16/22 (72.7%) and 20/22 (90.1%) with metronidazole sensitive strains (72.7% vs 90.1%, p-value=0.12; OR=3.75 [95%CI=0.6-31.5]). Minor adverse reactions included nausea, bitter taste, diarrhea and black stools but none of the patients dropped out from the study. Initial treatment with 7-day bismuth-based quadruple therapy including metronidazole, amoxycillin and pantoprazole is highly effective and well tolerated for metronidazole-sensitive H

  7. In situ forming pluronic® F127/chitosan hydrogel limits metronidazole transmucosal absorption.

    PubMed

    Malli, Sophia; Bories, Christian; Pradines, Bénédicte; Loiseau, Philippe M; Ponchel, Gilles; Bouchemal, Kawthar

    2017-03-01

    The objective of this work is to design topically-applied thermosensitive and mucoadhesive hydrogel containing metronidazole (MTZ) for the treatment of Trichomonas vaginalis infections. Hydrogel composed of pluronic® F127 (20wt%), chitosan (1wt%) and metronidazole MTZ (0.7wt%) mixture showed its ability to decrease by a factor 4 MTZ flux and apparent permeability absorption through vaginal mucosa. The impact of hydrogel on transmucosal penetration of MTZ was evaluated ex vivo on excised porcine vaginal mucosa mounted on Franz diffusion cell. The anti-T. vaginalis activity of MTZ formulated into F127/chitosan hydrogel was preserved since the viability curve evaluated in vitro was similar to MTZ solution. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Subjective adverse reactions to metronidazole in patients with amebiasis.

    PubMed

    Ohnishi, Kenji; Sakamoto, Naoya; Kobayashi, Ken-Ichiro; Iwabuchi, Sentaro; Nakamura-Uchiyama, Fukumi; Ajisawa, Atsushi; Yamauchi, Yuko; Takeshita, Nozomi; Yamamoto, Yasuyuki; Tsunoda, Takafumi; Yoshimura, Yukihiro; Tachikawa, Natsuo; Uehira, Tomoko

    2014-10-01

    Subjective adverse reactions to metronidazole were analyzed in 111 patients with amebiasis. Metronidazole was administered to 36 patients at a daily dose of 2250 mg and 75 patients at daily doses lower than 2250 mg. The reactions reported included nausea without vomiting in 11 (9.9%) patients, nausea with vomiting in 2 (1.8%), dysgeusia in 2 (1.8%), diarrhea in 1 (0.9%), headache in 1 (0.9%), numbness in 1 (0.9%), dizziness in 1 (0.9%), urticaria in 1 (0.9%), exanthema in 1 (0.9%), and discomfort in 1 (0.9%). Nausea was reported by 28% (10/36) of the patients receiving metronidazole at a daily dose of 2250 mg and 4% (3/75) of the patients receiving lower daily doses. The duration of the metronidazole administration in days was not associated with the appearance of nausea. No life-threatening adverse reactions were identified, and good clinical therapeutic effects were observed in 96% (107/111) of the patients. While metronidazole appears to be a safe anti-protozoal agent for patients with amebiasis, our results indicate that a daily metronidazole dose of 2250 mg is excessive for amebiasis, as it often induces nausea. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. The restoration of the vaginal microbiota after treatment for bacterial vaginosis with metronidazole or probiotics.

    PubMed

    Ling, Zongxin; Liu, Xia; Chen, Weiguang; Luo, Yueqiu; Yuan, Li; Xia, Yaxian; Nelson, Karen E; Huang, Shaolei; Zhang, Shaoen; Wang, Yuezhu; Yuan, Jieli; Li, Lanjuan; Xiang, Charlie

    2013-04-01

    Whether or not treatment with antibiotics or probiotics for bacterial vaginosis (BV) is associated with a change in the diversity of vaginal microbiota in women was investigated. One hundred fifteen women, consisting of 30 healthy subjects, 30 BV-positive control subjects, 30 subjects with BV treated with a 7-day metronidazole regimen, and 25 subjects with BV treated with a 10-day probiotics regimen, were analyzed to determine the efficacy and disparity of diversity and richness of vaginal microbiota using 454 pyrosequencing. Follow-up visits at days 5 and 30 showed a greater BV cure rate in the probiotics-treated subjects (88.0 and 96 %, respectively) compared to the metronidazole-treated subjects (83.3 and 70 %, respectively [p = 0.625 at day 5 and p = 0.013 at day 30]). Treatment with metronidazole reduced the taxa diversity and eradicated most of the BV-associated phylotypes, while probiotics only suppressed the overgrowth and re-established vaginal homeostasis gradually and steadily. Despite significant interindividual variation, the microbiota of the actively treated groups or participants constituted a unique profile. Along with the decrease in pathogenic bacteria, such as Gardnerella, Atopobium, Prevotella, Megasphaera, Coriobacteriaceae, Lachnospiraceae, Mycoplasma, and Sneathia, a Lactobacillus-dominated vaginal microbiota was recovered. Acting as vaginal sentinels and biomarkers, the relative abundance of Lactobacillus and pathogenic bacteria determined the consistency of the BV clinical and microbiologic cure rates, as well as recurrent BV. Both 7-day intravaginal metronidazole and 10-day intravaginal probiotics have good efficacy against BV, while probiotics maintained normal vaginal microbiota longer due to effective and steady vaginal microbiota restoration, which provide new insights into BV treatment.

  10. Metronidazole loaded pectin microspheres for colon targeting.

    PubMed

    Vaidya, Ankur; Jain, Aviral; Khare, Piush; Agrawal, Ram K; Jain, Sanjay K

    2009-11-01

    A multiparticulate system having pH-sensitive property and specific enzyme biodegradability for colon-targeted delivery of metronidazole was developed. Pectin microspheres were prepared using emulsion-dehydration technique. These microspheres were coated with Eudragit(R) S-100 using oil-in-oil solvent evaporation method. The SEM was used to characterize the surface of these microspheres and a distinct coating over microspheres could be seen. The in vitro drug release studies exhibited no drug release at gastric pH, however continuous release of drug was observed from the formulation at colonic pH. Further, the release of drug from formulation was found to be higher in the presence of rat caecal contents, indicating the effect of colonic enzymes on the pectin microspheres. The in vivo studies were also performed by assessing the drug concentration in various parts of the GIT at different time intervals which exhibited the potentiality of formulation for colon targeting. Hence, it can be concluded that Eudragit coated pectin microspheres can be used for the colon specific delivery of drug. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association

  11. Montmorillonite nanodevices for the colon metronidazole delivery.

    PubMed

    Calabrese, Ilaria; Cavallaro, Gennara; Scialabba, Cinzia; Licciardi, Mariano; Merli, Marcello; Sciascia, Luciana; Turco Liveri, Maria Liria

    2013-11-30

    The adsorption profiles of the antibiotic metronidazole (MNE) into the K10-montmorillonite (MMT-K10) clay and the subsequent release have been investigated as a function of pH and MNE/MMT-K10 ratio, in order to evaluate the potential of the MNE/MMT-K10 hybrids as controlled drug delivery system. The adsorption mechanism has been first elucidated by performing complementary equilibrium and kinetic studies and through the X-ray diffractometry (XRD) characterization of the obtained composite materials. The gathered results allowed us to propose a mechanism consisting of a multi-step pathway involving the neutral and the cationic form of the drug, which interact with different sites of the clay surfaces, i.e. the interlayer region and the faces of the lamella. In a second step the drug release kinetics has been studied under physiological pH mimicking conditions simulating the oral drug administration and delivery. For the sake of comparison the commercial formulation has also been employed for the release studies. The investigation of the release profiles and the comparison with the commercial formulation of the drug reveal that the new-tailor made formulation could be fruitful exploited for successfully prolonged the action of drug in the desired site. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Metronidazole-induced encephalopathy: not always a reversible situation.

    PubMed

    Hobbs, Kyle; Stern-Nezer, Sara; Buckwalter, Marion S; Fischbein, Nancy; Finley Caulfield, Anna

    2015-06-01

    Metronidazole is a nitroimidazole antimicrobial drug prescribed to treat infections caused by anaerobic bacteria and protozoa. Uncommonly, it causes central nervous system (CNS) toxicity manifesting as metronidazole-induced encephalopathy (MIE). Case report. A 65-year-old woman with hepatitis B cirrhosis (Child-Pugh class C, MELD 21) developed progressive encephalopathy to GCS 4 during a 3-week course of metronidazole for cholecystitis. Initial MRI was consistent with CNS metronidazole toxicity, with symmetrical T2 hyperintensity and generally restricted diffusion in bilateral dentate nuclei, corpus callosum, midbrain, superior cerebellar peduncles, internal capsules, and cerebral white matter. Laboratory values did not demonstrate significant electrolyte shifts, and continuous EEG was without seizure. High-dose thiamine was empirically administered. Lumbar puncture was not performed due to coagulopathy and thrombocytopenia. Despite discontinuation of metronidazole and keeping ammonia levels near normal, the patient did not improve. MRI was repeated 1 week after discontinuation of metronidazole. Although there was decreased DWI hyperintensity in the dentate nuclei, diffuse T2 hyperintensity persisted and even progressed in the brainstem, basal ganglia, and subcortical white matter. Petechial hemorrhages developed in bilateral corticospinal tracts and subcortical white matter. T1 hypointensity appeared in the corpus callosum. She was transitioned to comfort measures only and died 12 days later. MIE is an uncommon adverse effect of treatment with metronidazole that characteristically affects the dentate nuclei but may also involve the brainstem, corpus callosum, subcortical white matter, and basal ganglia. While the clinical symptoms and neuroimaging changes are usually reversible, persistent encephalopathy with poor outcome may occur.

  13. Busulfan and metronidazole: an often forgotten but significant drug interaction.

    PubMed

    Gulbis, Alison M; Culotta, Kirk S; Jones, Roy B; Andersson, Borje S

    2011-07-01

    To report the case of a clinically significant drug interaction between intravenous busulfan and oral metronidazole observed through busulfan therapeutic drug monitoring (TDM). A 7-year-old boy with a history of myelodysplasia that progressed to acute myeloid leukemia received busulfan with therapeutic drug monitoring (TDM), clofarabine, and thiotepa as a pretransplant conditioning regimen for a cord blood transplant. The patient received metronidazole the day after a busulfan test dose of 0.5 mg/kg was administered. On the day of the first busulfan therapeutic dose, TDM was performed and the clearance of busulfan was significantly decreased by 46%. After 2 doses of busulfan therapy, the course area under the curve was exceeded, requiring discontinuation of busulfan. Metronidazole is not known to affect glutathione or the glutathione S-transferase A1 (GSTA1) enzyme system or cytochrome P450 (CYP) 3A4. Busulfan is a bifunctional alkylating agent widely used in pretransplant conditioning regimens in patients undergoing stem cell transplantation for hematologic malignancies. Busulfan metabolism is best described by hepatic conjugation to glutathione by GSTA1, although some CYP-dependent pathways have been described. Currently there is 1 publication describing the drug interaction between oral busulfan and oral metronidazole, in which concomitant use of metronidazole resulted in higher busulfan trough concentrations and higher risk of veno-occlusive disease. Our case represents a possible drug interaction based on the Horn Drug Interaction Probability Scale. Though the mechanistic basis for this interaction is unknown, the risks and benefits of using metronidazole during and in close proximity to busulfan should be carefully considered and therapeutic alternatives to metronidazole should be used when appropriate.

  14. Metronidazole-induced central nervous system toxicity: a systematic review.

    PubMed

    Kuriyama, Akira; Jackson, Jeffrey L; Doi, Asako; Kamiya, Toru

    2011-01-01

    To assess patient and medication factors that contribute to metronidazole toxicity. We searched PUBMED from 1965 through April 7, 2011, and performed a hand search of bibliographies. Case reports or case series reporting metronidazole-induced central nervous toxicity. Two authors independently abstracted demographics, metronidazole indication, dose and duration, neurological manifestations, and outcomes as well as brain imaging findings. Among 64 patients, 48 (77%) had cerebellar dysfunction, 21 (33%) had altered mental status, and 8 (15%) had seizures. Patients' ages averaged 53.3 years (range, 12-87 years), and 64% were male. The median duration of metronidazole was 54 days, although 26% had taken it less than a week and 11% had taken it less than 72 hours. Among cases with outcome data, most patients either improved (n = 18 [29%]) or had complete resolution of their symptoms with discontinuation of metronidazole (n = 41 [65%]). There was no difference in resolution of symptom by age (P = 0.71) or sex (P = 0.34). The patients with cerebellar dysfunction were less likely to experience complete resolution than those with mental status changes or seizures (relative risk, 0.67; 95% confidence interval (CI), 0.49-0.92). Nearly all patients (n = 55 [86%]) underwent imaging of the brain: 44 (69%) underwent magnetic resonance imaging (MRI) and 12 (19%) underwent computed tomographic studies. All patients with cerebellar dysfunction had abnormalities on imaging: 93% (n = 39) had a cerebellar lesion, although numerous areas in the brain were affected. On follow-up MRIs, 25 patients (83%) had complete resolution of abnormalities. Metronidazole can rarely cause central nervous system toxicity; it does not seem to be a dose- or duration-related phenomenon. Most patients will have MRI abnormalities. Prognosis is excellent with metronidazole cessation.

  15. [Perioperative metronidazole-prophylaxis for cesarian section (author's transl].

    PubMed

    Gerstner, G; Kofler, E; Huber, J

    1980-12-01

    A prospective, randomized clinical trial was conducted in 103 patients undergoing cesarian section to assess the efficacy of prophylactic, intravenously administered Metronidazole on the infectious morbidity. A group of 53 patients with perioperative Metronidazol-prophylaxis was compared to a similar controll-group without prophylaxis. Bacteriologic swabs were taken from the cervix pre- and postoperatively, using anaerobic transport media. Prophylactic Metronidazole reduced postoperative fever of more than 38 degrees C on two subsequent days from 60% in the controll-group to 30,2% in the Metronidazole-group (p less than 0,01) wound infections were reduced from 18% without to 5,7% with prophylaxis (p less than 0,05) and Endometritis from 30% without to 13,2% with prophylaxis (p less than 0,05). An additional antibiotic therapy was necessary in 44% of the cases in the controllgroup, compared to 24,5% of the cases in the Metronidazolegroup (p less than 0,05). The mean duration of hospitalisation was reduced from 12,1 +/- 3,2 days in the controll-group to 11,2 +/- 2,1 in the Metronidazole-group (p less than 0,01). Anaerobic bacteria were isolated from the servical swabs in 60% preoperatively, with a still increasing incidence to 72% postoperatively, compared to 7% in the Metronidazole-group. Our results suggest, that prophylactic, intravenously administered Metronidazol reduces the infectious morbidity following cesarian section due to the reduction of the anaerobic flora at the female genital-tract.

  16. Metronidazole for the treatment of Tritrichomonas foetus in bulls.

    PubMed

    Love, David; Fajt, Virginia R; Hairgrove, Thomas; Jones, Meredyth; Thompson, James A

    2017-04-14

    Tritrichomonas foetus is a sexually transmitted protozoon that causes reproductive failure, among cattle, so disruptive that many western US states have initiated control programs. Current control programs are based on the testing and exclusion of individual bulls. Unfortunately, these programs are utilizing screening tests that are lacking in sensitivity. Blanket treatment of all the exposed bulls and adequate sexual rest for the exposed cows could provide a more viable disease control option. The objectives of this study were twofold. The first objective was to demonstrate effectiveness for metronidazole treatment of a bull under ideal conditions and with an optimized treatment regime. This type of study with a single subject is often referred to as an n-of-1 or single subject clinical trial. The second objective of the current study was to review the scientific basis for the banning of metronidazole for use in Food Animals by the Animal Medicinal Drug Use Clarification Act of 1994 (AMDUCA). Results from an antimicrobial assay indicated that metronidazole at a concentration of 0.5 μg/mL successfully eliminated in vitro protozoal growth of bovine Tritrichomonas foetus. The estimated effective intravenous dose was two treatments with 60 mg/kg metronidazole, 24 h apart. A bull that had tested positive for Tritrichomonas foetus culture at weekly intervals for 5 weeks prior to treatment was negative for Tritrichomonas foetus culture at weekly intervals for five consecutive weeks following this treatment regimen. An objective evaluation of the published evidence on the potential public health significance of using metronidazole to treat Tritrichomonas foetus in bulls provides encouragement for veterinarians and regulators to consider approaches that might lead to permitting the legal use of metronidazole in bulls. The study demonstrated successful inhibition of Tritrichomonas foetus both in vitro and in vivo with metronidazole. The current status of metronidazole

  17. Identification of intrinsically metronidazole-resistant clades of Gardnerella vaginalis.

    PubMed

    Schuyler, Jessica A; Mordechai, Eli; Adelson, Martin E; Sobel, Jack D; Gygax, Scott E; Hilbert, David W

    2016-01-01

    Gardnerella vaginalis is associated with bacterial vaginosis (BV), the most common cause of vaginal discharge. Metronidazole is a front-line therapy for BV, and treatment failure and recurrent disease are common problems. Whole-genome sequencing studies have revealed that G. vaginalis has a population structure that consists of 4 clades: clades 1 and 3 are associated with BV, whereas clades 2 and 4 are not. To determine if metronidazole susceptibility is associated with population structure, we analyzed 87 clinical isolates and found that metronidazole resistance (MIC ≥32 μg/mL) was highly associated with clade (P<0.0001), as 14/14 clade 3 isolates (100%) and 22/22 clade 4 isolates (100%) exhibited resistance, compared to only 16/37 clade 1 isolates (35%) and 1/14 clade 2 isolates (7.1%). The identification of intrinsically metronidazole-resistant G. vaginalis clades will facilitate future studies on the relationship between metronidazole resistance and BV treatment failure. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Glioblastoma multiforme: treatment by large dose fraction irradiation and metronidazole

    SciTech Connect

    Kapp, D.S.; Wagner, F.C.; Lawrence, R.

    1982-03-01

    In an attempt to overcome the possible radioresistance of glioblastoma multiforme related to the large shoulder on the in vitro survival curves and to sensitize hypoxic tumor cells, a treatment protocol was instituted at Yale University Medical Center and affiliated hospitals, using large dose fraction irradiation therapy in conjunction with the hypoxic cell sensitizer metronidazole. Nineteen patients with biopsy-confirmed, previously untreated, cerebral grade IV glioblastoma multiforme were, following surgery, irradiated once a week at 600 rad per fraction, 3.5 to 4 hours after ingestion of metronidazole, 6 gm/m/sup 2/. A total of 7 treatments were employed, with all patients maintained on antiseizure medications and corticosteroids. Metronidazole levels were determined prior to each treatment and patients were followed closely clinically and with serial computerized tomography (CT) scans. The treatment was well tolerated, in general, with no untoward side effects related to the high dose fraction irradiation. The majority of the patients experienced varying degrees of gastrointestinal upset lasting up to several hours following metronidazole administration. Three patients died of pulmonary emboli. One patient experienced moderately severe ototoxicity. A median survival of 9.4 months was obtained for all 19 patients, suggestive of a prolongation of survival compared to historical controls treated with conventionally fractionated radiation or with unconventional radiation fractionation schemes and metronidazole or misonidazole.

  19. Prevalence of metronidazole-resistant Helicobacter pylori in dyspeptic patients.

    PubMed

    Xia, H X; Daw, M A; Beattie, S; Keane, C T; O'Morain, C A

    1993-03-01

    Susceptibility to metronidazole of 213 clinical strains of H. pylori from dyspeptic patients was determined by a plate dilution method. Seventy two (33.8%) of the strains were resistant to metronidazole (MIC > 8 mg/L), 20 of these were from 24 patients who had received previously metronidazole (83.3%), giving a primary (pretreatment) resistance rate of 27.5% (52/189). The resistance rate was higher in women than in men, especially aged 50 to 59 years old (43.6% vs 23.3%, p < 0.001). The resistance rate was lower in patients at 60 or over (9.8%), but similar between the younger patients groups (38.8% - 49.0%). There was no difference in the resistance rate between peptic ulcer disease (32.6%) and nonulcer dyspepsia (34.7%). These data indicated that metronidazole resistance in H. pylori is absolutely associated with previous use of the drug, and the higher resistance rate in women may be due to the more frequent prescription of the drug for their gynaecological infection or operation. Therefore, testing of susceptibility of H. pylori to metronidazole is important. A new susceptibility testing technique, the E-test was evaluated in this study and found to give comparable results to the plate dilution method and also had the advantage of being simple to perform.

  20. Implications of metronidazole pharmacodynamics for therapy of trichomoniasis.

    PubMed

    Larsen, B; Wilson, A H; Glover, D D; Charles, D

    1986-01-01

    A liquid chromatographic technique for the detection of metronidazole (MDZ) and its major metabolites, combined with a vaginal sampling technique employing extraction of drug from vaginal swabs, was used to evaluate the concentration of MDZ in the vaginal fluid during therapy. Wide variation in the absolute concentration of unchanged drug was noted, although the average vaginal levels were about half the serum concentration 2 h after treatment had been initiated and comparable to the serum levels 6 and 24 h after treatment. Oral administration of MDZ invariably resulted in the presence of the drug in the serum and urine but the drug was not always detected in the vaginal secretions. The presence of the relatively inactive acetyl metabolite in the vaginal fluid of patients who failed to respond to therapy for trichomoniasis suggested the possible role of drug modification as a contributing factor in the lack of therapeutic success. The presence of MDZ in women in whom the cervix had previously been surgically removed attests to the transport or transudation of the drug across the vaginal epithelium without involvement of the secretory activity of the cervix.

  1. In vitro activity of rodogyl against putative periodontopathic bacteria.

    PubMed Central

    Quee, T C; Roussou, T; Chan, E C

    1983-01-01

    The minimal inhibitory concentrations of Rodogyl (composite tablet of metronidazole and spiramycin), metronidazole-spiramycin mixture, spiramycin, metronidazole, and tetracycline were determined for selected putative periodontopathic microorganisms. Rodogyl was active against almost all strains, including Bacteroides species and the anaerobic spirochetes. Synergism of the component drugs in the Rodogyl combination was noted against Propionibacterium species. Spiramycin activity against Actinomyces species was enhanced in the presence of metronidazole. PMID:6639002

  2. [Metronidazole-resistant trichomoniasis and successful therapy following high dosage].

    PubMed

    Weihe, J; Metelmann, C; Borner, K; Meingassner, J; Orfanos, C E

    1988-04-01

    A patient is reported who suffered for several months from a Trichomonas vaginalis infection that was resistant to the usual low-dose treatment with 5-nitro-imidazole derivatives. Following various ineffective therapeutic trials, the agent was isolated in order to determine its sensitivity to 5-nitro-imidazole. The resistance of the isolate to metronidazole was confirmed in vitro and in an animal experiment; the patient was therefore treated with high daily doses of metronidazole, 3 x 750 mg orally as well as 2 x 100 mg topically for 14 days. Substitution therapy with zinc was administered in order to normalize the patient's relatively low zinc serum levels. These measures finally led to a clinical cure and elimination of the pathogenic agent. This is the first confirmed case of a metronidazole-resistant Trichomonas vaginalis infection reported in the Federal Republic of Germany.

  3. Topical Metronidazole for Odor Control in Pressure Ulcers.

    PubMed

    Lyvers, Elizabeth; Elliott, David P

    2015-09-01

    There are many remedies that have been recommended for the treatment of foul odor associated with pressure ulcers. This article seeks to review the literature surrounding the use of metronidazole as a safe and effective solution to an oftentimes stubborn and frustrating problem. Other tools used to control odor include bleach-based solutions and charcoal dressings. Metronidazole, with its antianaerobic properties, appears to have a useful role in therapy when applied topically to a pressure ulcer. Commercially available products include 0.75% and 1% creams, gels, lotions, and intravenous solutions. Of the 59 cases viewed throughout several publications, 56 reported nearly complete odor resolution in two to seven days when metronidazole was applied to the wound two or three times daily. Virtually no systemic adverse events have been reported in the literature, despite the risk for systemic absorption. A need remains to monitor for toxicities such as nausea, gastrointestinal distress, and neural toxicities from long-term use.

  4. Metronidazole-Induced Bullous Pemphigoid: A Case Report

    PubMed Central

    Moitra, Saibal; Banerjee, Indranil; Sikder, Ayan; Das, Prasanta

    2015-01-01

    Bullous pemphigoid is an autoimmune cutaneous blistering disorder, the exact pathogenesis of which is still not fully elucidated. Drug-induced bullous pemphigoid eruptions are rare but have been reported earlier with the use of frusemide, psoralens, ibuprofen, galantamine hydrobromide, ACE inhibitors like captopril, spironolactone, penicillin, ampicillin, levofloxacin, penicillamine. We hereby report a case of metronidazole induced bullous pemphigoid (BP) in a 52-year-old male patient suffering from liver abscess following 4 days of drug administration. The skin biopsy findings obtained from the patient were consistent with the diagnosis of bullous pemphigoid (BP). Metronidazole was discontinued and symptomatic treatment was offered to the patient. Following withdrawal of metronidazole, the bullae subsided in the next 7-10 days without any significant residual scarring. The causality assessment performed as per the Naranjo algorithm revealed the case to be probable (Naranjo score 7). PMID:26816913

  5. [Mycoplasma hominis symbiosis and Trichomonas vaginalis metronidazole resistance].

    PubMed

    Wang, Pin-Jia; Xie, Cheng-Bin

    2012-06-30

    To investigate the relation of Mycoplasma hominis symbiosis and the resistance of Trichomonas vaginalis to metronidazole. From November 2010 to July 2011, 160 isolates of T. vaginalis were collected from the genital tract secretion of gynecological out-patients at the Sichuan Provincial Hospital for Women and Children. The minimum lethal concentration (MLC) to metronidazole of these isolates was determined by an in vitro sensitivity assay with different concentration gradients of metronidazole (from 1 to 1 024 microg/ml), and M. hominis DNA in T. vaginalis was detected by polymerase chain reaction (PCR) technique with specific 16S rRNA primers. After clearance of M. hominis from the parasites by 32 microg/ml doxycycline, MLC was determined and compared with that before clearance. MLC of metronidazole in T. vaginalis ranged from 1 to 256 microg/ml, with 61.3% isolates (98/160) ranging from 1 to 8 microg/ml, 26.3% isolates (42/160) ranging from 16 to 32 microg/ml, and 12.5% isolates (20/160) ranging from 64 to 256 microg/ml. 61 isolates were PCR positive for M. hominis DNA in the 160 isolates of T. vaginalis. The M. hominis DNA positive rate was significantly higher in the T. vaginalis isolates with higher MLC than those isolates with lower MLC (P<0.01). However, when M. hominis was cleared by doxycycline from 8 isolates among the 61 ones, no change was observed in sensitivity of the isolates to metronidazole. M. hominis symbiosis might be associated with the metronidazole-resistance of T. vaginalis. However, it needs direct evidence.

  6. Poly(acrylic acid-co-methyl methacrylate)/metronidazole systems: synthesis and complexation.

    PubMed

    Bialik-Wąs, Katarzyna; Pielichowski, Krzysztof

    2013-01-01

    We report on preparation of poly(acrylic acid-co-methyl methacrylate) (PAM) micro- and nanoparticles and, in the subsequent stage, complexation reaction with the active substance - metronidazole (MET). The drug release behavior of MET - loaded PAM micro- and nanoparticles was evaluated in water and phosphate buffered saline (PBS, 0.9% NaCl) at 37ºC. It has been found that introduction of MET into PAM micro- and nanoparticles enabled gradual and controlled release of the active substance. Structural analysis using FT-IR (ATR) and (1)H NMR, as well as surface morphology assessment by SEM, were performed.

  7. Investigation of Metronidazole Use during Pregnancy and Adverse Birth Outcomes

    PubMed Central

    Koss, Catherine A.; Baras, Dana C.; Lane, Sandra D.; Aubry, Richard; Marcus, Michele; Markowitz, Lauri E.

    2012-01-01

    To assess whether treatment with metronidazole during pregnancy is associated with preterm birth, low birth weight, or major congenital anomalies, we conducted chart reviews and an analysis of electronic data from a cohort of women delivering at an urban New York State hospital. Of 2,829 singleton/mother pairs, 922 (32.6%) mothers were treated with metronidazole for clinical indications, 348 (12.3%) during the first trimester of pregnancy and 553 (19.5%) in the second or third trimester. There were 333 (11.8%) preterm births, 262 (9.3%) infants of low birth weight, and 52 infants (1.8%) with congenital anomalies. In multivariable analysis, no association was found between metronidazole treatment and preterm birth (odds ratio [OR], 1.02 [95% confidence interval [CI], 0.80 to 1.32]), low birth weight (OR, 1.05 [95% CI, 0.77 to 1.43]), or treatment in the first trimester and congenital anomalies (OR, 0.86 [0.30 to 2.45]). We found no association between metronidazole treatment during the first or later trimesters of pregnancy and preterm birth, low birth weight, or congenital anomalies. PMID:22751543

  8. Sudden death due to metronidazole/ethanol interaction.

    PubMed

    Cina, S J; Russell, R A; Conradi, S E

    1996-12-01

    Metronidazole (Flagyl), a commonly prescribed antimicrobial agent, can produce a reaction similar to that of disulfiram (Antabuse) when administered to patients drinking ethanol. This drug/chemical interaction results in accumulation of acetaldehyde in the blood. Acetaldehyde is hepatotoxic, cardiotoxic, and arrythmogenic; no lethal serum acetaldehyde level has been established. Sudden death has been reported in patients taking disulfiram while using ethanol; no fatalities have been reported due to ethanol/ metronidazole interactions. Described is a case of a 31-year-old woman who died moments after an assault by a male companion, during which he inflicted minor physical trauma to her upper arm. Toxicologic analysis yielded elevated concentrations of serum ethanol (162 mg/d), acetaldehyde (4.6 mg/d), and metronidazole (0.42 mg/L). The cause of death was reported to be cardiac dysrhythmia due to acetaldehyde toxicity due to an ethanol/ metronidazole interaction. Autonomic stress associated with the assault is likely to have contributed to this woman's death. The mechanism of death is examined.

  9. Metronidazole in the treatment of non-specific vaginitis (NSV).

    PubMed Central

    Jerve, F; Berdal, T B; Bohman, P; Smith, C C; Evjen, O K; Gjønnaess, H; Gaasemyr, M; Hausken, L; Hesla, K; Hoftvedt, E

    1984-01-01

    In a large multicentre study of 429 patients with the usual signs and symptoms of non-specific vaginitis (NSV), we studied the effect of different doses of metronidazole. The patients were divided into five treatment groups as follows: group A was given 400 mg metronidazole three times daily for seven days, group B 2000 mg as a single dose, group C 2000 mg on days 1 and 2, group D 2000 mg on days 1 and 3, and group E was given 1200 mg metronidazole once daily for five days. At follow up examination four weeks from the start of treatment, patients in groups D and E showed the best clinical results with cure rates of 94.0% and 93.6% respectively. In addition the rate of reisolation of Gardnerella vaginalis was lowest in group D. We therefore recommend metronidazole 2000 mg on days 1 and 3 as routine treatment for non-specific or vaginitis associated with gardnerella. PMID:6375804

  10. A Redox Basis for Metronidazole Resistance in Helicobacter pylori▿

    PubMed Central

    Kaakoush, N. O.; Asencio, C.; Mégraud, F.; Mendz, G. L.

    2009-01-01

    Metronidazole resistance in Helicobacter pylori has been attributed to mutations in rdxA or frxA. Insufficient data correlating RdxA and/or FrxA with the resistant phenotype, and the emergence of resistant strains with no mutations in either rdxA or frxA, indicated that the molecular basis of H. pylori resistance to metronidazole required further characterization. The rdxA and frxA genes of four matched pairs of metronidazole-susceptible and -resistant strains were sequenced. The resistant strains had mutations in either rdxA, frxA, neither gene, or both genes. The reduction rates of five substrates suggested that metabolic differences between susceptible and resistant strains cannot be explained only by mutations in rdxA and/or frxA. A more global approach to understanding the resistance phenotype was taken by employing two-dimensional gel electrophoresis combined with tandem mass spectrometry analyses to identify proteins differentially expressed by the matched pair of strains with no mutations in rdxA or frxA. Proteins involved in the oxireduction of ferredoxin were downregulated in the resistant strain. Other redox enzymes, such as thioredoxin reductase, alkyl hydroperoxide reductase, and superoxide dismutase, showed a pI change in the resistant strain. The data suggested that metronidazole resistance involved more complex metabolic changes than specific gene mutations, and they provided evidence of a role for the intracellular redox potential in the development of resistance. PMID:19223619

  11. Tinidazole vs metronidazole for the treatment of bacterial vaginosis.

    PubMed

    Schwebke, Jane R; Desmond, Renee A

    2011-03-01

    The purpose of this study was to compare the efficacy of 2 different doses of tinidazole with metronidazole for the treatment of bacterial vaginosis and to compare the side effects of the drugs. Women were assigned randomly to receive metronidazole 500 mg twice daily, tinidazole 500 mg twice daily, or tinidazole 1 g twice, all for 7 days. Follow-up visits were conducted at days 14 and 28. Five hundred ninety-three women were enrolled. There were no significant differences between the treatment arms. Overall cure rates were 76.8% at 14 days and 64.5% at 1 month. Women who admitted to engaging in sexual intercourse during the study were significantly more likely to have bacterial vaginosis at the follow-up visit. There were no significant differences in adverse events across treatment arms. There were no differences in cure rates between metronidazole and either of the tinidazole dosing regimens that were studied. In addition, there were no important differences in the side-effect profiles of metronidazole and tinidazole. Copyright © 2011 Mosby, Inc. All rights reserved.

  12. Failure of thiabendazole and metronidazole in the treatment and suppression of guinea worm disease.

    PubMed

    Belcher, D W; Wunapa, F K; Ward, W B

    1975-05-01

    Guinea worm disease is endemic in West Africa. In 1973 a field drug trial was conducted to compare effectiveness, cost, and side-effects of thiabendazole and metronidazole in treating active guinea worm disease and preventing latent worms from emerging. A mass chemotherapy campaign was planned to follow the drug trial. Only 15.5% of the treated patients expelled the worm completely, and in 28.4% of the cases worms continued to appear. Both drugs were equally unsatisfactory in their anti-helminthic effect. Consequently, our efforts to control guinea worm have shifted from chemotherapy to chemical control of cyclops and improvement of rural water supplies.

  13. Effects of metronidazole analogues on Giardia lamblia: experimental infection and cell organization.

    PubMed

    Busatti, Haendel G N O; Alves, Ricardo J; Santana-Anjos, Karla G; Gil, Frederico F; Cury, Marcia C; Vannier-Santos, Marcos A; Gomes, Maria A

    2013-02-01

    The chemotherapeutic agents used for the treatment of giardiasis are often associated with adverse side effects and are refractory cases, due to the development of resistant parasites. Therefore the search for new drugs is required. We have previously reported the giardicidal effects of metronidazole (MTZ) and its analogues (MTZ-Ms, MTZ-Br, MTZ-N(3), and MTZ-I) on the trophozoites of Giardia lamblia. Now we evaluated the activity of some giardicidal MTZ analogues in experimental infections in gerbils and its effects on the morphology and ultrastructural organization of Giardia. The giardicidal activity in experimental infections showed ED(50) values significantly lower for MTZ-I and MTZ-Br when compared to MTZ. Transmission electron microscopy was employed to approach the mechanism(s) of action of MTZ analogues upon the protozoan. MTZ analogues were more active than MTZ in changing significantly the morphology and ultrastructure of the parasite. The analogues affected parasite cell vesicle trafficking, autophagy, and triggered differentiation into cysts. These results coupled with the excellent giardicidal activity and lower toxicity demonstrate that these nitroimidazole derivates may be important therapeutic alternatives for combating giardiasis. In addition, our results suggest a therapeutic advantage in obtaining synthetic metronidazole analogues for screening of activities against other infectious agents.

  14. Effects of Azithromycin, Metronidazole, Amoxicillin, and Metronidazole plus Amoxicillin on an In Vitro Polymicrobial Subgingival Biofilm Model

    PubMed Central

    Teles, Flavia; Starr, Jacqueline R.; Feres, Magda; Patel, Michele; Martin, Lynn

    2015-01-01

    Chronic periodontitis is one of the most prevalent human diseases and is caused by dysbiosis of the subgingival microbiota. Treatment involves primarily mechanical disruption of subgingival biofilms and, in certain cases, adjunctive use of systemic antibiotic therapy. In vitro biofilm models have been developed to study antimicrobial agents targeting subgingival species. However, these models accommodate a limited number of taxa, lack reproducibility, and have low throughput. We aimed to develop an in vitro multispecies biofilm model that mimics subgingival plaque, to test antimicrobial agents. Biofilms were cultivated using the Calgary Biofilm Device and were exposed to amoxicillin (AMX), metronidazole (MTZ), azithromycin (AZM), and AMX-MTZ at four different concentrations for 12, 24, or 36 h. Chlorhexidine (CHX) (0.12%) was used as the positive control. The compositions of the biofilms were analyzed by checkerboard DNA-DNA hybridization, and the percent reduction in biofilm metabolic activity was determined using 2,3,5-triphenyltetrazolium chloride and spectrophotometry. Thirty-five of the 40 species used in the inoculum were consistently recovered from the resulting in vitro biofilms. After 36 h of exposure at the 1:27 dilution, AMX-MTZ reduced metabolic activity 11% less than CHX (q = 0.0207) but 54% more than AMX (q = 0.0031), 72% more than MTZ (q = 0.0031), and 67% more than AZM (q = 0.0008). Preliminary evidence of a synergistic interaction between AMX and MTZ was also observed. In summary, we developed reproducible biofilms with 35 subgingival bacterial species, and our results suggested that the combination of AMX and MTZ had greater antimicrobial effects on these in vitro multispecies biofilms than expected on the basis of the independent effects of the drugs. PMID:25733510

  15. Effects of azithromycin, metronidazole, amoxicillin, and metronidazole plus amoxicillin on an in vitro polymicrobial subgingival biofilm model.

    PubMed

    Soares, Geisla M S; Teles, Flavia; Starr, Jacqueline R; Feres, Magda; Patel, Michele; Martin, Lynn; Teles, Ricardo

    2015-05-01

    Chronic periodontitis is one of the most prevalent human diseases and is caused by dysbiosis of the subgingival microbiota. Treatment involves primarily mechanical disruption of subgingival biofilms and, in certain cases, adjunctive use of systemic antibiotic therapy. In vitro biofilm models have been developed to study antimicrobial agents targeting subgingival species. However, these models accommodate a limited number of taxa, lack reproducibility, and have low throughput. We aimed to develop an in vitro multispecies biofilm model that mimics subgingival plaque, to test antimicrobial agents. Biofilms were cultivated using the Calgary Biofilm Device and were exposed to amoxicillin (AMX), metronidazole (MTZ), azithromycin (AZM), and AMX-MTZ at four different concentrations for 12, 24, or 36 h. Chlorhexidine (CHX) (0.12%) was used as the positive control. The compositions of the biofilms were analyzed by checkerboard DNA-DNA hybridization, and the percent reduction in biofilm metabolic activity was determined using 2,3,5-triphenyltetrazolium chloride and spectrophotometry. Thirty-five of the 40 species used in the inoculum were consistently recovered from the resulting in vitro biofilms. After 36 h of exposure at the 1:27 dilution, AMX-MTZ reduced metabolic activity 11% less than CHX (q = 0.0207) but 54% more than AMX (q = 0.0031), 72% more than MTZ (q = 0.0031), and 67% more than AZM (q = 0.0008). Preliminary evidence of a synergistic interaction between AMX and MTZ was also observed. In summary, we developed reproducible biofilms with 35 subgingival bacterial species, and our results suggested that the combination of AMX and MTZ had greater antimicrobial effects on these in vitro multispecies biofilms than expected on the basis of the independent effects of the drugs.

  16. Evaluation of the effects of albendazole and metronidazole on the ultrastructure of Giardia duodenalis, Trichomonas vaginalis and Spironucleus muris using transmission electron microscopy.

    PubMed

    Oxberry, M E; Thompson, R C; Reynoldson, J A

    1994-08-01

    The three closely related parasitic protozoa, Giardia duodenalis, Trichomonas vaginalis and Spironucleus muris, all have very different sensitivities to albendazole and metronidazole. Ultrastructural studies reveal that the cytoskeletal elements of the ventral disk in G. duodenalis are affected by albendazole, whereas the other two parasites, neither of which possess this structure, are not affected by albendazole to the same extent. This suggests that albendazole may be having its primary affect on G. duodenalis by binding to cytoskeletal proteins and ultimately causing death of the parasite. Death may be occurring as the parasite loses its ability to adhere to the intestinal villi and obtain nutrients. Metronidazole showed a different pattern of activity against the three parasites. The evidence obtained from these ultrastructural studies supports the current theory that metronidazole adversely affects protozoa by disrupting inner cell membranes.

  17. Appearance of a metronidazole-resistant Helicobacter pylori strain in an infected-ICR-mouse model and difference in eradication of metronidazole-resistant and -sensitive strains.

    PubMed Central

    Matsumoto, S; Washizuka, Y; Matsumoto, Y; Tawara, S; Ikeda, F; Yokota, Y; Karita, M

    1997-01-01

    We tested whether antibiotic-resistant strains appeared in vivo after the failure of treatment using the Helicobacter pylori-infected euthymic mouse model. The numbers of colonies isolated from 56 ICR mice 2 weeks after 4 days of treatment with metronidazole (3.2, 10, or 32 mg/kg of body weight) or amoxicillin (1, 3.2 or 10 mg/kg), with treatment started 4 days after H. pylori CPY2052 inoculation, were counted, and the isolated strains were tested for their sensitivities to two antibiotics to rule out the presence of antibiotic-resistant strains. One metronidazole-resistant strain was detected in a mouse treated with 10 mg of metronidazole per kg, and the MIC of metronidazole for this strain was 25 microg/ml, compared to a MIC of 1.56 microg/ml for the original strain. However, no resistant strain was detected in the amoxicillin treatment group. After the examination described above, mice challenged with a metronidazole-resistant or -sensitive strain isolated from the stomach of a mouse were treated with metronidazole or amoxicillin. The metronidazole-resistant strain was more difficult to eradicate in vivo than the sensitive strain after treatment with metronidazole but not after treatment with amoxicillin. Thus, a metronidazole-resistant H. pylori strain was selected by insufficient treatment, but no resistant strain was selected with amoxicillin. Eradication of a metronidazole-resistant H. pylori strain in vivo required a higher dosage than eradication of a metronidazole-sensitive H. pylori strain. These results may explain one of the reasons for H. pylori treatment failure. PMID:9420026

  18. Nitazoxanide, a Potential Drug for Eradication of Helicobacter pylori with No Cross-Resistance to Metronidazole

    PubMed Central

    Mégraud, Francis; Occhialini, Alessandra; Rossignol, Jean François

    1998-01-01

    Nitazoxanide, a thiazolide compound, and its desacetyl derivative, tizoxanide, have antimicrobial properties against anaerobic bacteria, as well as against helminths and protozoa. Because the treatment of Helicobacter pylori infection may be jeopardized by metronidazole resistance, nitazoxanide and tizoxanide were tested in vitro against these bacteria. The MICs of these two compounds were determined by agar dilution and were compared to those of metronidazole. Exposure to subinhibitory concentrations of nitazoxanide was also carried out by the method of Szybalski (W. Szybalski and V. Bryson, J. Bacteriol. 64:489–499, 1952). The MICs of nitazoxanide and tizoxanide for 103 strains ranged from 0.25 to 8 μg/ml, with the MIC at which 50% of strains are inhibited (MIC50) being 1 μg/ml and the MIC90 being 4 μg/ml, and no resistant strain was detected, whereas strains resistant to metronidazole were detected. When 10 strains were successively subcultured on medium containing nitazoxanide, no significant change in the MICs of this compound was observed. A pilot study of nitazoxanide for the treatment of H. pylori infection was carried out with 86 patients in association with 20 mg of omeprazole. An eradication rate of 83% (95% confidence interval, 64% to 94%) was obtained in a per-protocol analysis in the group receiving 1 g of nitazoxanide orally twice daily, and a few side effects were observed. The failures could not be explained by the selection of resistant strains since the MICs of nitazoxanide were similar for six pairs of isolates (proven to be the same strain by random amplified polymorphic DNA analysis in four cases) cultured before and after the treatment failure. Nitazoxanide exhibits good antimicrobial activity against H. pylori without the problem of acquired resistance which is encountered with metronidazole and has been demonstrated to have a satisfactory effect in a dose-ranging pilot study. It is therefore a good candidate to be included in treatment

  19. A comparison of the efficacy of metronidazole vaginal gel and Myrtus (Myrtus communis) extract combination and metronidazole vaginal gel alone in the treatment of recurrent bacterial vaginosis

    PubMed Central

    Masoudi, Mansoureh; Rafieian Kopaei, Mahmoud; Miraj, Sepideh

    2017-01-01

    Objective: Due to the high incidence of bacterial vaginosis (BV) and its resistance to chemical medications and considering the anti-bacterial and anti-fungal effects of Myrtus communis, the present study aimed to compare the therapeutic effects of the vaginal gel of M. communis 2% (in metronidazole base) with metronidazole vaginal gel 0.75% alone on BV. Materials and Methods: This research was a randomized controlled clinical trial conducted on 80 women of 18-40 years old with BV. Patients were divided into two groups of 40 women. Diagnostic criteria were Amsel's criteria and Gram staining. The first group received vaginal gel of metronidazole plus M. communis 2% and the second group received metronidazole vaginal gel alone for five consecutive nights. Therapeutic effects and Amsel’s criteria were assessed after one week. Finally, the data were analyzed by SPSS 16 using t-test and Chi square tests. Results: There was a significant difference in the therapeutic response between the two groups. The results demonstrated that the combination of metronidazole and M. communis had a higher efficiency (p<0.05). The patients receiving M. communis in metronidazole gel base did not experience any recurrent BV, but 30% of patients taking metronidazole alone faced recurrent BV after three weeks of follow up. Conclusion: Findings of the study suggested that adding M. communis extract to metronidazole increases the efficiency of BV treatment. PMID:28348968

  20. A comparison of the efficacy of metronidazole vaginal gel and Myrtus (Myrtus communis) extract combination and metronidazole vaginal gel alone in the treatment of recurrent bacterial vaginosis.

    PubMed

    Masoudi, Mansoureh; Rafieian Kopaei, Mahmoud; Miraj, Sepideh

    2017-01-01

    Due to the high incidence of bacterial vaginosis (BV) and its resistance to chemical medications and considering the anti-bacterial and anti-fungal effects of Myrtus communis, the present study aimed to compare the therapeutic effects of the vaginal gel of M. communis 2% (in metronidazole base) with metronidazole vaginal gel 0.75% alone on BV. This research was a randomized controlled clinical trial conducted on 80 women of 18-40 years old with BV. Patients were divided into two groups of 40 women. Diagnostic criteria were Amsel's criteria and Gram staining. The first group received vaginal gel of metronidazole plus M. communis 2% and the second group received metronidazole vaginal gel alone for five consecutive nights. Therapeutic effects and Amsel's criteria were assessed after one week. Finally, the data were analyzed by SPSS 16 using t-test and Chi square tests. There was a significant difference in the therapeutic response between the two groups. The results demonstrated that the combination of metronidazole and M. communis had a higher efficiency (p<0.05). The patients receiving M. communis in metronidazole gel base did not experience any recurrent BV, but 30% of patients taking metronidazole alone faced recurrent BV after three weeks of follow up. Findings of the study suggested that adding M. communis extract to metronidazole increases the efficiency of BV treatment.

  1. Metabolic differences between metronidazole resistant and susceptible strains of Tritrichomonas foetus.

    PubMed

    Cerkasovová, A; Cerkasov, J; Kulda, J

    1984-04-01

    Tritrichomonas foetus mutants resistant to metronidazole lack the hydrogenosomal enzymes pyruvate: ferredoxin oxidoreductase and hydrogenase. Hydrogenosomes of these organisms did not oxidize pyruvate or produce ATP in its presence. Elimination of hydrogenosomal metabolism of pyruvate was compensated by an increased rate of glycolysis. The resistant mutants excreted no organic acids and H2 as metabolic end products. Glycolysis of the resistant T. foetus KV1-1MR-100 can be summarized as 1 mol glucose----2 mol ethanol + 2 mol CO2. The parent strain KV1, excreting H2, CO2 and acidic end products, converted about 10% of glucose to ethanol. Both strains produced ethanol from pyruvate through the action of two cytoplasmic enzymes: pyruvate decarboxylase and alcohol dehydrogenase. The specific activity of the former enzyme, catalyzing nonoxidative decarboxylation of pyruvate to acetaldehyde, was nearly seven times higher in the resistant than in the parent strain. Alcohol dehydrogenase reducing acetaldehyde to ethanol was specific to NADPH; it catalyzed the reverse reaction only slowly, and displayed similar activities in both resistant and sensitive trichomonads. Development of anaerobic metronidazole resistance in T. foetus depended on the loss of pyruvate:ferredoxin oxidoreductase as well as on the ability to increase alcoholic fermentation.

  2. Norfloxacin and metronidazole topical formulations for effective treatment of bacterial infections and burn wounds

    PubMed Central

    Dua, Kamal; Malipeddi, Venkata Ramana; Madan, Jyotsna; Gupta, Gaurav; Chakravarthi, Srikumar; Awasthi, Rajendra; Kikuchi, Irene Satiko; De Jesus Andreoli Pinto, Terezinha

    2016-01-01

    Introduction Our various previous findings have shown the suitability of norfloxacin in the treatment of bacterial infections and burn wounds in alone as well as in combination with Curcuma longa in various topical (ointments, gels, and creams) and transdermal drug delivery systems. Aims and methods Keeping these facts in consideration, we have made an another attempt to prepare semisolid formulations containing 1% w/w of norfloxacin and metronidazole with different bases like Carbopol, polyethylene glycol, and hydroxypropylmethyl cellulose for effective treatment of bacterial infections and burn wounds. The prepared formulations were evaluated for physicochemical parameters, in vitro drug release, antimicrobial activity, and burn wound healing properties. Results The prepared formulations were compared with Silver Sulfadiazine cream 1%, USP. Antimicrobial activity of norfloxacin semisolid formulations was found to be equally effective against both aerobic and anaerobic bacteria in comparison to a marketed formulation of Silver Sulfadiazine 1% cream, USP. Based on the burn wound healing property, the prepared norfloxacin semisolid formulation was found to be in good agreement with marketed Silver Sulfadiazine 1% cream, USP. Conclusions These findings suggest formulations containing norfloxacin and metronidazole may also prove as an effective alternative for existing remedies in the treatment of bacterial infections and burn wounds. PMID:28386462

  3. Crystal growth by solvent evaporation and characterization of metronidazole

    NASA Astrophysics Data System (ADS)

    Ramukutty, S.; Ramachandran, E.

    2012-07-01

    Single crystals of metronidazole were crystallized by the slow solvent evaporation method and used as seeds to grow bulk crystals of size 8.0×6.5×2.0 mm3 using top-seeded submerged solution growth. The crystals were characterized using single crystal X-ray diffraction. Fourier transform infrared spectral analysis was made for the absorption bands of various functional groups present in the crystal. UV-vis absorption spectrum was used to identify the presence of nitroimidazole in metronidazole. Morphology study revealed that the growth is prominent along the c-axis and the prominent face is {010}. Thermal stability and thermal decomposition were analyzed using thermo calorimetry.

  4. Comparison of sequential intravenous/oral ciprofloxacin plus metronidazole with intravenous ceftriaxone plus metronidazole for treatment of complicated intra-abdominal infections.

    PubMed

    Wacha, Hannes; Warren, Brian; Bassaris, Harry; Nikolaidis, Paul

    2006-08-01

    Intra-abdominal infections are a substantial clinical problem and an important cause of morbidity and death in the hospital. Optimal treatment requires both source control and antibiotic therapy. Sequential intravenous (IV) to oral therapy may improve patient convenience and reduce total health care costs. In this randomized, double-blind trial, the efficacy of sequential IV-to-oral ciprofloxacin plus metronidazole was compared with ceftriaxone plus metronidazole in adult patients with complicated intra-abdominal infections. The trial enrolled 531 patients, who began with IV therapy. Patients who improved clinically were switched to oral therapy on day three or later. The clinical and bacteriological responses four to six weeks after the end of therapy and the safety of the two regimens were assessed. To maintain blinding, the patients received placebo IV in the ciprofloxacin group or placebo orally in the ceftriaxone group. A total of 475 patients (235 ciprofloxacin plus metronidazole, 240 ceftriaxone plus metronidazole) were valid for evaluation of efficacy. All patients were included in the safety analysis. Of the patients valid for efficacy, 78% of the ciprofloxacin plus metronidazole group and 81% of the ceftriaxone plus metronidazole group were eligible for a switch to oral therapy. The clinical success rates were 98.9% and 96.9%, respectively, which were statistically equivalent. The clinical success rates for all patients, including those on continuous IV therapy, were 90.6% and 87.9%. Source control was achieved in more than 90% of the patients. The bacteriological eradication rates were similar in the two groups. Bacterial complications (e.g., surgical site infections, abscesses) were encountered more often in the ceftriaxone plus metronidazole group. Sequential ciprofloxacin plus metronidazole IV-to-oral therapy was statistically equivalent to ceftriaxone plus metronidazole. The switch to oral therapy with ciprofloxacin plus metronidazole was as

  5. Biowaiver monographs for immediate release solid oral dosage forms: metronidazole.

    PubMed

    Rediguieri, Camila F; Porta, Valentina; G Nunes, Diana S; Nunes, Taina M; Junginger, Hans E; Kopp, Sabine; Midha, Kamal K; Shah, Vinod P; Stavchansky, Salomon; Dressman, Jennifer B; Barends, Dirk M

    2011-05-01

    Literature data relevant to the decision to allow a waiver of in vivo bioequivalence (BE) testing for the approval of immediate release (IR) solid oral dosage forms containing metronidazole are reviewed. Metronidazole can be assigned to Biopharmaceutics Classification System Class I. Most BE studies that were identified reported the investigated formulations to be bioequivalent, indicating the risk of bioinequivalence to be low. Formulations showing differences in bioavailability showed dissimilarities in in vitro dissolution profiles. Furthermore, metronidazole has a wide therapeutic index. It is concluded that a biowaiver for solid IR formulations is justified, provided: (a) the test product and its comparator are both rapidly dissolving; (b) meet similarity of the dissolution profiles at pH 1.2, 4.5, and 6.8; (c) the test product contains only excipients present in IR drug products approved in International Conference on Harmonisation (ICH) or associated countries in the same dosage form; and (d) if the test product contains sorbitol, sodium laurilsulfate, or propylene glycol, the test product needs to be qualitatively and quantitatively identical to its comparator with respect to these excipients [corrected]..

  6. [Convulsive seizures and polyneuritis in a patient with lupus treated with metronidazole (author's transl)].

    PubMed

    Herreman, G; Krainik, F; Betous, F; Nicolas, M O; Mundler, B

    1981-01-01

    A 20-year-old patient with biologically-confirmed lupus developed a perirenal abscess following puncture biopsy of the kidney. Postoperative treatment included metronidazole at a mean dose of 2.5 g daily for 68 days (total dose : 165 g). Generalised convulsive seizures occurred on four occasions, associated with paresthesia of the four limbs, but without loss of motor or reflex activity, though some distal hypoesthesia was detected. An acute lupus attack was eliminated, the convulsive seizures not recurring after discontinuation of treatment, and the paresthesias diminishing progressively over a period of three months. Electrical investigations showed lack of motor anomalies but a marked reduction in sensory conduction. This is the 13th reported case of polyneuritis due to metronidazole, the 4th case of convulsive seizures, and the first case in which both manifestations occurred. The plasma concentration curve after oral administration of 1 g of the product to this patient demonstrated that the product was not being metabolised in a pathological manner.

  7. In vivo interaction of anti-cancer drugs with misonidazole or metronidazole: cyclophosphamide and BCNU.

    PubMed Central

    Tannock, I. F.

    1980-01-01

    The addition of misonidazole (MISO) or metronidazole (METRO) to treatment with cyclophosphamide (CY) increased delay to regrowth of 2 experimental tumours. The effect was observed for large an small tumours, was present for doses of MISO that are ineffective for killing hypoxic cells, and required that it be given with, or shortly before CY. Mice receiving combined treatment had more weight loss and myelosuppression than those receiving CY alone, and the Therapeutic Index was lower. MISO caused a marked increase in growth delay when combined with BCNU to treat the KHT sarcoma. This effect was observed for small and large tumours, required simultaneous administration of drugs, and also led to increased host toxicity. There was no therapeutic advantage from combined treatment. Survival of aerobic or anoxic Chinese hamster ovary (CHO) cells was assessed after exposure in vitro to serum from mice that had received CY or BCNU alone. MISO alone, or combined treatment. Results of these experiments suggest that (1) MISO delays the excretion or breakdown of active metabolites of CY, and (2) at a dose that does not kill hypoxic cells, it may selectively "sensitize" hypoxic cells (but not aerobic cells) to the action of BCNU. The presence of other undetermined interactions of BCNU and MISO is inferred from the increased toxicity to (aerobic) normal tissue. Misonidazole or metronidazole should be used with caution in patients who are receiving BCNU or cyclophosphamide. PMID:7459221

  8. Draft Genome Sequence of a Metronidazole-Resistant Gardnerella vaginalis Isolate

    PubMed Central

    Schuyler, Jessica A.; Chadwick, Sean G.; Mordechai, Eli; Adelson, Martin E.; Gygax, Scott E.

    2015-01-01

    We report the draft genome sequence of a Gardnerella vaginalis strain (3549624) isolated from a vaginal specimen. G. vaginalis is associated with bacterial vaginosis, the most common cause of vaginal discharge, which is often treated with metronidazole. This isolate is highly resistant to metronidazole (MIC, 500 µg/ml) and may be useful for comparative genomic studies to determine the molecular basis of metronidazole resistance in this species. PMID:26337887

  9. Two Multidrug-Resistant Clinical Isolates of Bacteroides fragilis Carry a Novel Metronidazole Resistance nim Gene (nimJ)

    PubMed Central

    Veeranagouda, Yaligara; Hsi, Justin; Meggersee, Rosemary; Abratt, Valerie; Wexler, Hannah M.

    2013-01-01

    Two multidrug-resistant Bacteroides fragilis clinical isolates contain and express a novel nim gene, nimJ, that is not recognized by the “universal” nim primers and can confer increased resistance to metronidazole when introduced into a susceptible strain on a multicopy plasmid. HMW615, an appendiceal isolate, contains at least two copies of nimJ on its genome, while HMW616, an isolate from a patient with sepsis, contains one genomic copy of nimJ. B. fragilis NimJ is phylogenetically closer to Prevotella baroniae NimI and Clostridium botulinum NimA than to the other known Bacteroides Nim proteins. The predicted protein structure of NimJ, based on fold recognition analysis, is consistent with the crystal structures derived for known Nim proteins, and specific amino acid residues important for substrate binding in the active site are conserved. This study demonstrates that the “universal” nim primers will not detect all nim genes with the ability to confer metronidazole resistance, but nimJ alone cannot account for the very high metronidazole MICs of these resistant clinical isolates. PMID:23716049

  10. Controlled study on thymol + eugenol vaginal douche versus econazole in vaginal candidiasis and metronidazole in bacterial vaginosis.

    PubMed

    Sosto, Francesco; Benvenuti, Claudio

    2011-01-01

    Bacterial vaginosis (BV) and vaginal candidiasis (VC) are usually managed with topical antibiotics. This study compared the efficacy of a thymol + eugenol vaginal douche (SD) (CAS nr. thymol: 89-83-8 and eugenol: 97-53-0), with econazole (CAS 27220-47-9) in VC and metronidazole (CAS 443-48-1) in BV, as suppository reference therapies. Thymol and eugenol are natural antibacterial and antimycotic active ingredients extracted from plants. A multicentre, parallel group, randomized study was performed, after stratification for diagnosis. Twenty-three Italian gynaecological units enrolled 459 patients (232 BV, 227 VC). The treatments applied were as follows: SD 1 douche/day (Saugella lavanda Attiva) for 1 week, 1 metronidazole vaginal suppository/night for 1 week and 1 econazole vaginal suppository/night for 3 days. Clinical evaluations were performed before and 1 week after treatment. A similar significant symptom reduction was observed with metronidazole and SD in BV and with econazole and SD in VC. SD was found to be an effective prescription drug in minor recurrent vaginal infectious episodes and its use can reduce the repeated exposure to antibiotics.

  11. Ethnicity association of Helicobacter pylori virulence genotype and metronidazole susceptibility

    PubMed Central

    Alfizah, Hanafiah; Rukman, Awang Hamat; Norazah, Ahmad; Hamizah, Razlan; Ramelah, Mohamed

    2013-01-01

    AIM: To characterise the cag pathogenicity island in Helicobacter pylori (H. pylori) isolates by analysing the strains’ vacA alleles and metronidazole susceptibilities in light of patient ethnicity and clinical outcome. METHODS: Ninety-five H. pylori clinical isolates obtained from patients with dyspepsia living in Malaysia were analysed in this study. Six genes in the cagPAI region (cagE, cagM, cagT, cag13, cag10 and cag67) and vacA alleles of the H. pylori isolates were identified by polymerase chain reaction. The isolates’ metronidazole susceptibility was also determined using the E-test method, and the resistant gene was characterised by sequencing. RESULTS: More than 90% of the tested isolates had at least one gene in the cagPAI region, and cag67 was predominantly detected in the strains isolated from the Chinese patients, compared with the Malay and Indian patients (P < 0.0001). The majority of the isolates (88%) exhibited partial deletion (rearrangement) in the cagPAI region, with nineteen different patterns observed. Strains with intact or deleted cagPAI regions were detected in 3.2% and 8.4% of isolates, respectively. The prevalence of vacA s1m1 was significantly higher in the Malay and Indian isolates, whereas the isolates from the Chinese patients were predominantly genotyped as vacA s1m2 (P = 0.018). Additionally, the isolates from the Chinese patients were more sensitive to metronidazole than the isolates from the Malay and Indian patients (P = 0.047). Although we attempted to relate the cagPAI genotypes, vacA alleles and metronidazole susceptibilities to disease outcome, no association was observed. The vacA alleles were distributed evenly among the strains with intact, partially deleted or deleted cagPAI regions. Interestingly, the strains exhibiting an intact cagPAI region were sensitive to metronidazole, whereas the strains with a deleted cagPAI were more resistant. CONCLUSION: Successful colonisation by different H. pylori genotypes is

  12. Cloning of Bacteroides fragilis plasmid genes affecting metronidazole resistance and ultraviolet survival in Escherichia coli

    SciTech Connect

    Wehnert, G.U.; Abratt, V.R.; Goodman, H.J.; Woods, D.R. )

    1990-03-01

    Since reduced metronidazole causes DNA damage, resistance to metronidazole was used as a selection method for the cloning of Bacteroides fragilis genes affecting DNA repair mechanisms in Escherichia coli. Genes from B. fragilis Bf-2 were cloned on a recombinant plasmid pMT100 which made E. coli AB1157 and uvrA, B, and C mutant strains more resistant to metronidazole, but more sensitive to far uv irradiation under aerobic conditions. The loci affecting metronidazole resistance and uv sensitivity were linked and located on a 5-kb DNA fragment which originated from the small 6-kb cryptic plasmid pBFC1 present in B. fragilis Bf-2 cells.

  13. Differential Expression and Immunolocalization of Antioxidant Enzymes in Entamoeba histolytica Isolates during Metronidazole Stress

    PubMed Central

    Iyer, Lakshmi Rani; Singh, Nishant; Verma, Anil Kumar; Paul, Jaishree

    2014-01-01

    Entamoeba histolytica infections are endemic in the Indian subcontinent. Five to eight percent of urban population residing under poor sanitary conditions suffers from Entamoeba infections. Metronidazole is the most widely prescribed drug used for amoebiasis. In order to understand the impact of metronidazole stress on the parasite, we evaluated the expression of two antioxidant enzymes, peroxiredoxin and FeSOD, in Entamoeba histolytica isolates during metronidazole stress. The results reveal that, under metronidazole stress, the mRNA expression levels of these enzymes did not undergo any significant change. Interestingly, immunolocalization studies with antibodies targeting peroxiredoxin indicate differential localization of the protein in the cell during metronidazole stress. In normal conditions, all the Entamoeba isolates exhibit presence of peroxiredoxin in the nucleus as well as in the membrane; however with metronidazole stress the protein localized mostly to the membrane. The change in the localization pattern was more pronounced when the cells were subjected to short term metronidazole stress compared to cells adapted to metronidazole. The protein localization to the cell membrane could be the stress response mechanism in these isolates. Colocalization pattern of peroxiredoxin with CaBp1, a cytosolic protein, revealed that the membrane and nuclear localization was specific to peroxiredoxin during metronidazole stress. PMID:25013795

  14. Bioadhesive Controlled Metronidazole Release Matrix Based on Chitosan and Xanthan Gum

    PubMed Central

    Eftaiha, Ala’a F.; Qinna, Nidal; Rashid, Iyad S.; Al Remawi, Mayyas M.; Al Shami, Munther R.; Arafat, Tawfiq A.; Badwan, Adnan A.

    2010-01-01

    Metronidazole, a common antibacterial drug, was incorporated into a hydrophilic polymer matrix composed of chitosan xanthan gum mixture. Hydrogel formation of this binary chitosan-xanthan gum combination was tested for its ability to control the release of metronidazole as a drug model. This preparation (MZ-CR) was characterized by in vitro, ex vivo bioadhesion and in vivo bioavailability study. For comparison purposes a commercial extended release formulation of metronidazole (CMZ) was used as a reference. The in vitro drug-release profiles of metronidazole preparation and CMZ were similar in 0.1 M HCl and phosphate buffer pH 6.8. Moreover, metronidazole preparation and CMZ showed a similar detachment force to sheep stomach mucosa, while the bioadhesion of the metronidazole preparation was higher three times than CMZ to sheep duodenum. The results of in vivo study indicated that the absorption of metronidazole from the preparation was faster than that of CMZ. Also, MZ-CR leads to higher metronidazole Cmax and AUC relative to that of the CMZ. This increase in bioavailability might be explained by the bioadhesion of the preparation at the upper part of the small intestine that could result in an increase in the overall intestinal transit time. As a conclusion, formulating chitosan-xanthan gum mixture as a hydrophilic polymer matrix resulted in a superior pharmacokinetic parameters translated by better rate and extent of absorption of metronidazole. PMID:20559494

  15. Differential expression and immunolocalization of antioxidant enzymes in Entamoeba histolytica isolates during metronidazole stress.

    PubMed

    Iyer, Lakshmi Rani; Singh, Nishant; Verma, Anil Kumar; Paul, Jaishree

    2014-01-01

    Entamoeba histolytica infections are endemic in the Indian subcontinent. Five to eight percent of urban population residing under poor sanitary conditions suffers from Entamoeba infections. Metronidazole is the most widely prescribed drug used for amoebiasis. In order to understand the impact of metronidazole stress on the parasite, we evaluated the expression of two antioxidant enzymes, peroxiredoxin and FeSOD, in Entamoeba histolytica isolates during metronidazole stress. The results reveal that, under metronidazole stress, the mRNA expression levels of these enzymes did not undergo any significant change. Interestingly, immunolocalization studies with antibodies targeting peroxiredoxin indicate differential localization of the protein in the cell during metronidazole stress. In normal conditions, all the Entamoeba isolates exhibit presence of peroxiredoxin in the nucleus as well as in the membrane; however with metronidazole stress the protein localized mostly to the membrane. The change in the localization pattern was more pronounced when the cells were subjected to short term metronidazole stress compared to cells adapted to metronidazole. The protein localization to the cell membrane could be the stress response mechanism in these isolates. Colocalization pattern of peroxiredoxin with CaBp1, a cytosolic protein, revealed that the membrane and nuclear localization was specific to peroxiredoxin during metronidazole stress.

  16. High-dose vaginal maintenance metronidazole for recurrent bacterial vaginosis: a pilot study.

    PubMed

    Aguin, Tina; Akins, Robert A; Sobel, Jack D

    2014-05-01

    The purpose of this study was to explore the benefit of high-dose intravaginal metronidazole as a maintenance therapy in reducing recurrence rates of bacterial vaginosis (BV). Eighteen women with a history of recurrent BV and symptomatic BV were treated with metronidazole 750 mg suppository intravaginally daily for 7 days. Those in remission by Amsel criteria received metronidazole 750 mg twice weekly for 3 months with further follow-up for 3 months. High-dose metronidazole intravaginally was associated with rare clinical recurrence during the period of use. After cessation of suppression therapy, recurrence was high.

  17. Outcome of metronidazole therapy for Clostridium difficile disease and correlation with a scoring system.

    PubMed

    Belmares, Jaime; Gerding, Dale N; Parada, Jorge P; Miskevics, Scott; Weaver, Frances; Johnson, Stuart

    2007-12-01

    To determine the response rate of Clostridium difficile disease (CDD) to treatment with metronidazole and assess a scoring system to predict response to treatment with metronidazole when applied at the time of CDD diagnosis. Retrospective review of patients with CDD who received primary treatment with metronidazole. We defined success as diarrhea resolution within 6 days of therapy. A CDD score was defined prospectively using variables suggested to correlate with disease severity. Among 102 evaluable patients, 72 had a successful response (70.6%). Twenty-one of the remaining 30 patients eventually responded to metronidazole, but required longer treatment, leaving 9 'true failures'. The mean CDD score was higher among true failures (2.89+/-1.4) than among all metronidazole responders (0.77+/-1.0) (p<.0001). The score was greater than 2 in 67% of true failures and 2 or less in 94% of metronidazole responders. Leukocytosis and abnormal CT scan findings were individual factors associated with a higher risk of metronidazole failure. Only 71% of CDD patients responded to metronidazole within 6 days, but the overall response rate was 91%. A CDD score greater than 2 was associated with metronidazole failure in 6 of 9 true failures. The CDD score will require prospective validation.

  18. Furazolidone- and Nitrofurantoin-Resistant Helicobacter pylori: Prevalence and Role of Genes Involved in Metronidazole Resistance

    PubMed Central

    Kwon, Dong H.; Lee, Miae; Kim, J. J.; Kim, J. G.; El-Zaatari, F. A. K.; Osato, M. S.; Graham, D. Y.

    2001-01-01

    The prevalence of furazolidone, nitrofurantoin, and metronidazole resistance among Helicobacter pylori strains was assessed with 431 clinical isolates. Fifty-two percent were metronidazole resistant, compared to 2% (7 of 431) with resistance to furazolidone and nitrofurantoin. All seven furazolidone- and nitrofurantoin-resistant isolates were also metronidazole resistant. rdxA, frxA, and fdxB knockouts did not result in furazolidone or nitrofurantoin resistance. These data suggest that furazolidone and nitrofurantoin may be good alternatives to metronidazole for treating H. pylori infection. PMID:11120984

  19. [Metronidazole-Induced Encephalopathy during Brain Abscess Treatment:Two Case Reports].

    PubMed

    Yokoyama, Yuka; Asaoka, Katsuyuki; Sugiyama, Taku; Uchida, Kazuki; Shimbo, Daisuke; Kobayashi, Satoshi; Itamoto, Koji

    2015-10-01

    Metronidazole is a widely used antibiotic against anaerobic bacteria and protozoa. We report two cases of metronidazole-induced encephalopathy(MIE)during treatment of a brain abscess with metronidazole. The patients developed mental disturbance, and brain MRI showed reversible signals on DWI, FLAIR, and T2. Case 1: A 48-year-old woman was admitted to our hospital with a cerebellar abscess. We initiated treatment with oral metronidazole. After taking the medication, she developed mental disturbance, and her brain MRI showed a hyperintensity within the corpus callosum. We suspected metronidazole toxicity and discontinued metronidazole treatment. The symptoms resolved rapidly within a week, and the hyperintensity on the MRI disappeared. Case 2: A 22-year-old man was admitted to our hospital with a brain abscess. We initiated treatment with oral metronidazole. On day 38, he developed mental disturbance, and his MRI showed hyperintensities within the bilateral dentate nuclei and corpus callosum. These symptoms were consistent with MIE. After cessation of metronidazole, his symptoms and abnormal MRI signals completely disappeared.

  20. Reversible metronidazole-induced cerebellar toxicity in a multiple transplant recipient.

    PubMed

    Graves, Tracey D; Condon, Marie; Loucaidou, Marina; Perry, Richard J

    2009-10-15

    Metronidazole-induced central nervous system (CNS) toxicity causes a spectrum of neurological symptoms including ataxia, encephalopathy and peripheral neuropathy. It is associated with characteristic MRI changes of high signal intensity in the dentate nuclei. Given the increasing use of metronidazole, it is import to recognise this drug as a cause of ataxia, as it is entirely reversible on drug withdrawal.

  1. Universal high-level primary metronidazole resistance in Helicobacter pylori isolated from children in Egypt.

    PubMed

    Sherif, May; Mohran, Zaynab; Fathy, Hanan; Rockabrand, David M; Rozmajzl, Patrick J; Frenck, Robert W

    2004-10-01

    Antimicrobial susceptibility testing was performed on 48 isolates of Helicobacter pylori recovered from Egyptian children undergoing routine endoscopies. The isolates were universally highly resistant to metronidazole, but resistance to other tested antimicrobial agents was rare (4% for clarithromycin, erythromycin, and azithromycin resistance versus 2% for ciprofloxacin and ampicillin resistance). Use of metronidazole for the treatment of H. pylori in Egypt should be avoided.

  2. Comparison between the efficacy of metronidazole vaginal gel and Berberis vulgaris (Berberis vulgaris) combined with metronidazole gel alone in the treatment of bacterial vaginosis

    PubMed Central

    Masoudi, Mansoure; Kopaei, Mahmoud Rafieian; Miraj, Sepideh

    2016-01-01

    Background Bacterial vaginosis is one of the most prevalent complications among reproductive-aged women. Antibacterial and antifungal effects of Berberis vulgaris have been demonstrated in vitro and in vivo. Objectives This study aimed to compare the therapeutic effects of the vaginal gel of Berberis vulgaris 5% (in metronidazole base) with metronidazole vaginal gel 0.75% on bacterial vaginosis on 80 patients referred to the Hajar Hospital from January 2012 to April 2013. Methods This study was a randomized clinical trial research on 80 women affected by bacterial vaginosis, who were randomly divided into two groups of 40 participants. Diagnostic criteria were Amsel’s criteria and Gram stain. Berberis vulgaris 5% (in metronidazole gel base) or metronidazole vaginal gel for five-night usage was prescribed to each group, and after two to seven days therapeutic effects and Amsel criteria were assessed. Data analysis was performed by SPSS 16 using Student t-test, chi-square, and ANOVA tests. Results Findings of the study showed a statistically significant difference with regard to treatment response between the study groups (p<0.001), and the Berberis vulgaris group had a better response than the metronidazole gel group. The patients in groups of Berberis vulgaris in a metronidazole gel base did not experience any relapse, but, in the metronidazole group, 30% of patients experienced relapse during three weeks’ follow-up. Conclusions Findings of the study showed that adding Berberis vulgaris fruit extract on metronidazole improve the efficacy of bacterial vaginosis therapy. Clinical trial registration The trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the IRCT ID: IRCT201411102085N13. Funding Shahrekord University of Medical Sciences supported this research. PMID:27757195

  3. Comparison between the efficacy of metronidazole vaginal gel and Berberis vulgaris (Berberis vulgaris) combined with metronidazole gel alone in the treatment of bacterial vaginosis.

    PubMed

    Masoudi, Mansoure; Kopaei, Mahmoud Rafieian; Miraj, Sepideh

    2016-08-01

    Bacterial vaginosis is one of the most prevalent complications among reproductive-aged women. Antibacterial and antifungal effects of Berberis vulgaris have been demonstrated in vitro and in vivo. This study aimed to compare the therapeutic effects of the vaginal gel of Berberis vulgaris 5% (in metronidazole base) with metronidazole vaginal gel 0.75% on bacterial vaginosis on 80 patients referred to the Hajar Hospital from January 2012 to April 2013. This study was a randomized clinical trial research on 80 women affected by bacterial vaginosis, who were randomly divided into two groups of 40 participants. Diagnostic criteria were Amsel's criteria and Gram stain. Berberis vulgaris 5% (in metronidazole gel base) or metronidazole vaginal gel for five-night usage was prescribed to each group, and after two to seven days therapeutic effects and Amsel criteria were assessed. Data analysis was performed by SPSS 16 using Student t-test, chi-square, and ANOVA tests. Findings of the study showed a statistically significant difference with regard to treatment response between the study groups (p<0.001), and the Berberis vulgaris group had a better response than the metronidazole gel group. The patients in groups of Berberis vulgaris in a metronidazole gel base did not experience any relapse, but, in the metronidazole group, 30% of patients experienced relapse during three weeks' follow-up. Findings of the study showed that adding Berberis vulgaris fruit extract on metronidazole improve the efficacy of bacterial vaginosis therapy. The trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the IRCT ID: IRCT201411102085N13. Shahrekord University of Medical Sciences supported this research.

  4. A novel metronidazole fluorescent nanosensor based on graphene quantum dots embedded silica molecularly imprinted polymer.

    PubMed

    Mehrzad-Samarin, Mina; Faridbod, Farnoush; Dezfuli, Amin Shiralizadeh; Ganjali, Mohammad Reza

    2017-06-15

    A novel optical nanosensor for detection of Metronidazole in biological samples was reported. Graphene quantum dots embedded silica molecular imprinted polymer (GQDs-embedded SMIP) was synthesized and used as a selective fluorescent probe for Metronidazole detection. The new synthesized GQDs-embedded SMIP showed strong fluorescent emission at 450nm excited at 365nm which quenched in presence of Metronidazole as a template molecule.. The quenching was proportional to the concentration of Metronidazole in a linear range of at least 0.2μM to 15μM. The limit of detection for metronidazole determination was obtained 0.15μM. The nanosensor successfully worked in plasma matrixes. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. D-allose and D-psicose reinforce the action of metronidazole on trichomonad.

    PubMed

    Harada, Masakazu; Kondo, Emi; Hayashi, Hiromi; Suezawa, Chigusa; Suguri, Setsuo; Arai, Meiji

    2012-04-01

    The effects of D-allose and D-psicose on Tritrichomonas foetus were examined. They were cultured in F-bouillon medium including glucose, but had never increased when glucose was substituted to those sugars. When cultured in a medium including a dose of ED(50) metronidazole and those sugars, trichomonad density was significantly less than that in a medium with metronidazole only. D-Allose remarkably reinforced the action of metronidazole. This means there are some interactions between metronidazole and those sugars. Although the mechanism is not clear, by using those sugars for treatment with metronidazole, the drug dosage could be lowered and the development of drug resistance of trichomonad parasites might be prevented.

  6. [Helicobacter pylori resistance against metronidazole in Switzerland: implications for eradication therapy?].

    PubMed

    Sieber, C C; Frei, R; Beglinger, C; Mossi, S; Binek, J; Schaufelberger, H; Fried, R; Stalder, G A

    1994-08-09

    Gastroduodenal ulcers are strongly associated with Helicobacter pylori (HP) infection. Successful eradication drastically diminishes ulcer recurrence. Most of the eradication schemes include metronidazole (Flagyl). The present study was designed to establish the metronidazole resistance rate in Switzerland. Antral biopsies were taken in 153 patients with suspected ulcers (115 men, 38 women, mean age 46 +/- 16 [SD] years) during upper endoscopy for bacteriological testing. Metronidazole resistance (> 8 micrograms/ml) was found in 47/153 (31%) of the isolates. Resistance was found in no case to amoxicillin (Clamoxyl) (0/104 = 0%) and only in 3% (2/66) to clarithromycin (Klazid). Metronidazole resistance of HP in a third of the isolates studied is comparable to numbers found in other European countries. These findings raise the question whether eradication schemes including metronidazole without prior sensitivity testing are justified. Amoxicillin and clarithromycin appear to be valid alternatives.

  7. FG90 chitosan as a new polymer for metronidazole mucoadhesive tablets for vaginal administration.

    PubMed

    Perioli, Luana; Ambrogi, Valeria; Pagano, Cinzia; Scuota, Stefania; Rossi, Carlo

    2009-07-30

    Topical administration of the antibacterial metronidazole (MET) represents the most common therapy in the treatment of bacterial vaginosis (BV). The formulations generally available for BV therapy are creams, gels, vaginal lavages and vaginal suppositories. In this study, a new dosage form, containing MET, was developed with the aim to realize vaginal mucoadhesive tablets by including bioadhesive polymers as chitosan (FG90C), polyvinylpyrrolidone (PVPK90) and polycarbophil (PCPAA1), blended in different ratios. All formulations were characterized by studies of DSC, friability, hardness, hydration, mucoadhesion, in vitro release and antibacterial activity. All polymer mixtures employed were used to prepare tablets with the compactness and hardness so as allow the application on vaginal mucosa. FG90C performances improved in particular when mixed to PVPK90 (1:1 ratio). This kind of delivery system is suitable for formulating MET for topical application representing a good alternative to traditional dosage forms for vaginal topical administration.

  8. Clindamycin vaginal cream vs oral metronidazole in the treatment of bacterial vaginosis.

    PubMed

    Arredondo, J L; Higuera, F; Hidalgo, H; Narcio, L; Casanova, G; Beltran, M; Sanchez, C J

    1992-01-01

    This study was designed to compare the safety/efficacy of the treatment of 2% clindamycin vaginal cream and oral metronidazole in 184 women with bacterial vaginosis. This was a randomized, prospective, multicenter, double-blind, controlled study. Patients were randomized to either Clindamycin phosphate vaginal cream 2%, 5 gm intravaginally at bedtime, and placebo oral metronidazole capsules taken twice daily, or oral metronidazole capsules, 500 mg, taken twice daily, and placebo clindamycin vaginal cream, 5 gm to be administered intravaginally at bedtime. All treatments were for 7 days. Patients were seen for followup at 4-13 days and 20-43 days after completion of protocol therapy. 2 investigators in Mexico City enrolled a total of 184 patients (91 clindamycin and 93 metronidazole). 1 patient never received drugs after enrollment, leaving 183 valuable for safety. A total of 114 were valuable for efficacy. Protocol regimens were comparable in efficacy (p=0.22) and the percentage of cure/improvement was 87% in the clindamycin group compared to 79% in the metronidazole group. No relapse was observed in the clindamycin group, as opposed to 7% in the metronidazole group. The clindamycin group had a failure of 13% while this was 15% in the metronidazole group. Both treatments were well-tolerated. Most of the events were either vulvovaginal irritation upon application of the study drug, or the development of vaginitis/cervicitis. The 1 event classified as serious in this study (metronidazole group) was generalized rash which, in the opinion of the investigator, was related to the study drug. There were 4 nongenital tract side effects (1 gastrointestinal, 2 dermatologic, and 1 allergy) all in the metronidazole group. The authors can conclude that clindamycin 2% vaginal cream is at least as effective as orally administered metronidazole for the treatment of bacterial vaginosis in nonpregnant women.

  9. A prospective study of risk factors and historical trends in metronidazole failure for Clostridium difficile infection

    PubMed Central

    Hu, Mary Y.; Maroo, Seema; Kyne, Lorraine; Cloud, Jeffrey; Tummala, Sanjeev; Katchar, Kianoosh; Dreisbach, Valley; Noddin, Laura; Kelly, Ciarán P.

    2009-01-01

    Background & Aims Recent studies of C. difficile infection (CDI) indicate a dramatic increase in metronidazole failure. The aims of this study were to compare current and historical rates of metronidazole failure and identify risk factors for metronidazole failure. Methods 89 patients with CDI in 2004–2006 were followed for 60 days. Data were compared to a historical cohort of 63 CDI patients studied prospectively in 1998. Metronidazole failure was defined as persistent diarrhea after 10 days of therapy or a change of therapy to vancomycin. Stool samples were analyzed for the presence of NAP-1 strain. Results Metronidazole failure rates were 35% in both the 1998 and 2004–2006 cohorts. There was no difference in the median time to resolution of diarrhea (8 vs. 5 days, p = 0.52) or the proportion with more than 10 days of diarrhea (35% vs. 29%, p = 0.51). Risk factors for metronidazole failure included recent cephalosporin use (OR 32, 95% CI 5–219), CDI on admission (OR 23, 95% CI 3–156), and transfer from another hospital (OR 11, 95% CI 2–72). The frequency of NAP-1 infection in patients with and without metronidazole failure was similar (26% vs. 21%, p = 0.67). Conclusions We found no difference in metronidazole failure rates in 1998 and 2004–2006. Patients with recent cephalosporin use, CDI on admission, and transfer from another hospital were more likely to fail metronidazole and may benefit from early aggressive therapy. Infection with the epidemic NAP-1 strain was not associated with metronidazole failure in endemic CDI. PMID:19081526

  10. Evidence for Lateral Transfer of Genes Encoding Ferredoxins, Nitroreductases, NADH Oxidase, and Alcohol Dehydrogenase 3 from Anaerobic Prokaryotes to Giardia lamblia and Entamoeba histolytica

    PubMed Central

    Nixon, Julie E. J.; Wang, Amy; Field, Jessica; Morrison, Hilary G.; McArthur, Andrew G.; Sogin, Mitchell L.; Loftus, Brendan J.; Samuelson, John

    2002-01-01

    Giardia lamblia and Entamoeba histolytica are amitochondriate, microaerophilic protists which use fermentation enzymes like those of bacteria to survive anaerobic conditions within the intestinal lumen. Genes encoding fermentation enzymes and related electron transport peptides (e.g., ferredoxins) in giardia organisms and amebae are hypothesized to be derived from either an ancient anaerobic eukaryote (amitochondriate fossil hypothesis), a mitochondrial endosymbiont (hydrogen hypothesis), or anaerobic bacteria (lateral transfer hypothesis). The goals here were to complete the molecular characterization of giardial and amebic fermentation enzymes and to determine the origins of the genes encoding them, when possible. A putative giardia [2Fe-2S]ferredoxin which had a hypothetical organelle-targeting sequence at its N terminus showed similarity to mitochondrial ferredoxins and the hydrogenosomal ferredoxin of Trichomonas vaginalis (another luminal protist). However, phylogenetic trees were star shaped, with weak bootstrap support, so we were unable to confirm or rule out the endosymbiotic origin of the giardia [2Fe-2S]ferredoxin gene. Putative giardial and amebic 6-kDa ferredoxins, ferredoxin-nitroreductase fusion proteins, and oxygen-insensitive nitroreductases each tentatively supported the lateral transfer hypothesis. Although there were not enough sequences to perform meaningful phylogenetic analyses, the unique common occurrence of these peptides and enzymes in giardia organisms, amebae, and the few anaerobic prokaryotes suggests the possibility of lateral transfer. In contrast, there was more robust phylogenetic evidence for the lateral transfer of G. lamblia genes encoding an NADH oxidase from a gram-positive coccus and a microbial group 3 alcohol dehydrogenase from thermoanaerobic prokaryotes. In further support of lateral transfer, the G. lamblia NADH oxidase and adh3 genes appeared to have an evolutionary history distinct from those of E. histolytica. PMID

  11. Tribulus terrestris ameliorates metronidazole-induced spermatogenic inhibition and testicular oxidative stress in the laboratory mouse

    PubMed Central

    Kumari, Mrinalini; Singh, Poonam

    2015-01-01

    Objective: The present study was undertaken to evaluate the protective effects of the fruit extract of Tribulus terrestris (TT) on the metronidazole (MTZ)-induced alterations in spermatogenesis, sperm count, testicular functions, and oxidative stress. Materials and Methods: Thirty adult Swiss strain mice were divided into six groups. Animals of Groups I and II served as untreated and vehicle-treated controls, while that of Groups III and IV were administered with MTZ (500 mg/kg BW/day) and TT (200 mg/kg BW/day) alone for 28 days, respectively. Low (100 mg/kg BW/day) and high (200 mg/kg BW/day) doses of TT along with MTZ (500 mg/kg BW/day) were administered for 28 days in the mice of Groups V and VI, respectively. Twenty four hours after the last treatment, all the animals were euthanized to study the histological changes in the testis and sperm count in the epididymis. Testicular functional markers, lipid peroxidation (LPO) and the activities of antioxidant enzymes, e.g., superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, were also assessed in the mice of all the groups. Results: Metronidazole caused marked alterations in the testicular weight, spermatogenesis, activities of antioxidant enzymes, lactate dehydrogenase, alkaline phosphatase, and the level of LPO. The epididymal sperm count also declined significantly in MTZ-treated group. These changes were partially restored following co-administration of 500 mg/kg BW/day of MTZ and 100 mg/kg BW/day of TT. However, in the mice co-administered with 500 mg/kg BW/day of MTZ and 200 mg/kg BW/day of TT, the changes reverted back completely, similar to that of the controls. Conclusion: The fruit extract of TT ameliorates the MTZ-induced alterations in the testis. PMID:26069369

  12. Molecular analysis of the carbapenem and metronidazole resistance mechanisms of Bacteroides strains reported in a Europe-wide antibiotic resistance survey.

    PubMed

    Sóki, József; Eitel, Zsuzsa; Urbán, Edit; Nagy, Elisabeth

    2013-02-01

    Here we examine the carbapenem and metronidazole resistance mechanisms of 640 Bacteroides strains reported in the 2008-2009 European antibiotic susceptibility survey. Of the 22 strains with elevated imipenem minimum inhibitory concentrations (≥4 μg/mL), 10 were cfiA-positive and out of these 5 carried activating insertion sequence (IS) elements in the upstream regions of the cfiA genes. However, resistant strains with cfiA genes but with no activating IS elements were found (n=2) as well as a resistant strain with no cfiA gene. In the former the resistance phenotypes by Etest were heterogeneous, whilst in the latter no carbapenemase production was seen; both mechanisms have been rarely observed, examined and characterised. Interestingly, few (n=3) nim-positive strains were found, including one metronidazole-resistant strain harbouring nimE activated by ISBf6, and two susceptible strains harbouring chromosomally located nim genes.

  13. Subinhibitory concentrations of metronidazole increase biofilm formation in Clostridium difficile strains.

    PubMed

    Vuotto, Claudia; Moura, Ines; Barbanti, Fabrizio; Donelli, Gianfranco; Spigaglia, Patrizia

    2016-03-01

    Resistance mechanism to metronidazole is still poorly understood, even if the number of reports on Clostridium difficile strains with reduced susceptibility to this antibiotic is increasing. In this study, we investigated the ability of the C. difficile strains 7032994, 7032985 and 7032989, showing different susceptibility profiles to metronidazole but all belonging to the PCR ribotype 010, to form biofilm in vitro in presence and absence of subinhibitory concentrations of metronidazole. The quantitative biofilm production assay performed in presence of metronidazole revealed a significant increase in biofilm formation in both the susceptible strain 7032994 and the strain 7032985 exhibiting a reduced susceptibility to this antibiotic, while antibiotic pressure did not affect the biofilm-forming ability of the stable-resistant strain 7032989. Moreover, confocal microscopy analysis showed an abundant biofilm matrix production by the strains 7032994 and 7032885, when grown in presence of metronidazole, but not in the stable-resistant one. These results seem to demonstrate that subinhibitory concentrations of metronidazole are able to enhance the in vitro biofilm production of the above-mentioned PCR ribotype 010 C. difficile strains, susceptible or with reduced susceptibility to this antibiotic, suggesting a possible role of biofilm formation in the multifactorial mechanism of metronidazole resistance developed by C. difficile. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Effect of metronidazole use on tacrolimus concentrations in transplant patients treated for Clostridium difficile.

    PubMed

    Early, C R; Park, J M; Dorsch, M P; Pogue, K T; Hanigan, S M

    2016-10-01

    Two case reports suggest that metronidazole treatment for Clostridium difficile infections (CDI) increases tacrolimus (TAC) trough levels. The primary objective of this study was to determine the clinical significance of this potential interaction in transplant patients receiving CDI treatment. Currently, no robust literature exists to estimate a magnitude of pharmacokinetic interaction between metronidazole and TAC. In this retrospective study, the effects of CDI and metronidazole treatment on TAC levels in 52 adult solid organ transplant patients were investigated. The primary outcome was to determine the difference in dose-normalized TAC levels between baseline and symptom resolution in patients treated with metronidazole or vancomycin. The secondary outcome was to determine the difference in dose-normalized TAC levels at baseline and CDI diagnosis. The average change in log-transformed dose-normalized TAC levels from baseline to symptom resolution was 0.99 for metronidazole (n = 35) and 1.04 for vancomycin (n = 17) treatment. The mean difference between the groups was 0.96 (95% confidence interval: 0.74-1.24). No significant difference was found between dose-normalized TAC levels at CDI diagnosis and baseline (P = 0.37). CDI treatment with metronidazole was not associated with a >30% increase in TAC levels compared with vancomycin. Both treatment groups required TAC dose adjustments to maintain goal TAC levels and those treated with metronidazole did not require a significantly greater dose adjustment. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Characterization of a Stable, Metronidazole-Resistant Clostridium difficile Clinical Isolate

    PubMed Central

    Lynch, Tarah; Chong, Patrick; Zhang, Jason; Hizon, Romeo; Du, Tim; Graham, Morag R.; Beniac, Daniel R.; Booth, Timothy F.; Kibsey, Pamela; Miller, Mark; Gravel, Denise; Mulvey, Michael R.

    2013-01-01

    Background Clostridium difficile are Gram-positive, spore forming anaerobic bacteria that are the leading cause of healthcare-associated diarrhea, usually associated with antibiotic usage. Metronidazole is currently the first-line treatment for mild to moderate C. difficile diarrhea however recurrence occurs at rates of 15–35%. There are few reports of C. difficile metronidazole resistance in the literature, and when observed, the phenotype has been transient and lost after storage or exposure of the bacteria to freeze/thaw cycles. Owing to the unstable nature of the resistance phenotype in the laboratory, clinical significance and understanding of the resistance mechanisms is lacking. Methodology/Principal Findings Genotypic and phenotypic characterization was performed on a metronidazole resistant clinical isolate of C. difficile. Whole-genome sequencing was used to identify potential genetic contributions to the phenotypic variation observed with molecular and bacteriological techniques. Phenotypic observations of the metronidazole resistant strain revealed aberrant growth in broth and elongated cell morphology relative to a metronidazole-susceptible, wild type NAP1 strain. Comparative genomic analysis revealed single nucleotide polymorphism (SNP) level variation within genes affecting core metabolic pathways such as electron transport, iron utilization and energy production. Conclusions/Significance This is the first characterization of stable, metronidazole resistance in a C. difficile isolate. The study provides an in-depth genomic and phenotypic analysis of this strain and provides a foundation for future studies to elucidate mechanisms conferring metronidazole resistance in C. difficile that have not been previously described. PMID:23349739

  16. Characterization of a stable, metronidazole-resistant Clostridium difficile clinical isolate.

    PubMed

    Lynch, Tarah; Chong, Patrick; Zhang, Jason; Hizon, Romeo; Du, Tim; Graham, Morag R; Beniac, Daniel R; Booth, Timothy F; Kibsey, Pamela; Miller, Mark; Gravel, Denise; Mulvey, Michael R

    2013-01-01

    Clostridium difficile are gram-positive, spore forming anaerobic bacteria that are the leading cause of healthcare-associated diarrhea, usually associated with antibiotic usage. Metronidazole is currently the first-line treatment for mild to moderate C. difficile diarrhea however recurrence occurs at rates of 15-35%. There are few reports of C. difficile metronidazole resistance in the literature, and when observed, the phenotype has been transient and lost after storage or exposure of the bacteria to freeze/thaw cycles. Owing to the unstable nature of the resistance phenotype in the laboratory, clinical significance and understanding of the resistance mechanisms is lacking. Genotypic and phenotypic characterization was performed on a metronidazole resistant clinical isolate of C. difficile. Whole-genome sequencing was used to identify potential genetic contributions to the phenotypic variation observed with molecular and bacteriological techniques. Phenotypic observations of the metronidazole resistant strain revealed aberrant growth in broth and elongated cell morphology relative to a metronidazole-susceptible, wild type NAP1 strain. Comparative genomic analysis revealed single nucleotide polymorphism (SNP) level variation within genes affecting core metabolic pathways such as electron transport, iron utilization and energy production. This is the first characterization of stable, metronidazole resistance in a C. difficile isolate. The study provides an in-depth genomic and phenotypic analysis of this strain and provides a foundation for future studies to elucidate mechanisms conferring metronidazole resistance in C. difficile that have not been previously described.

  17. Topical metronidazole can reduce pain after surgery and pain on defecation in postoperative hemorrhoidectomy.

    PubMed

    Ala, Shahram; Saeedi, Majid; Eshghi, Fariborz; Mirzabeygi, Parastou

    2008-02-01

    Topical metronidazole (10 percent) has been previously demonstrated to decrease postoperative pain after hemorrhoidectomy. The aim of this study was to evaluate the effect of topical metronidazole (10 percent) in reducing postoperative and after-defecation pain of hemorrhoidectomy. A double-blind, randomized trial was conducted to compare posthemorrhoidectomy pain with use of topical metronidazole (10 percent) vs. placebo carrier, applied to surgical site. Forty-seven patients were randomly allocated to receive metronidazole (n=25) or placebo (n=22). Pain was assessed using a visual analog scale preoperatively and on postoperative hours 6 and 12 and at days 1, 2, 7, and 14. The use of narcotic, additional analgesics, and complications were recorded. (Pain scores were calculated and compared with baseline values and control group (t test, SPSS ver.10). Patients in the topical metronidazole group had significantly less postoperative pain than those in the placebo group up to day 14 (P metronidazole group, after-defecation pain was ranked significantly lower at day 2 (P=0.016) and patients required fewer additional analgesics postoperatively on days 2 and 7 (P metronidazole significantly reduce posthemorrhoidectomy discomfort, and postoperative defecation pain is reduced compared with that of the placebo control group.

  18. Helicobacter pylori infection treated with a tripotassium dicitrato bismuthate and metronidazole combination.

    PubMed

    Weil, J; Bell, G D; Powell, K; Morden, A; Harrison, G; Gant, P W; Jones, P H; Trowell, J E

    1990-12-01

    Seventy-two patients with H. pylori infection in their antral mucosa took part in the study. Forty-three received metronidazole 400 mg t.d.s. for two weeks, plus De-Nol tabs 2 b.d. for four weeks, and the remaining 29 patients received metronidazole 400 mg t.d.s. for two weeks plus De-Nol liquid 5 ml q.d.s. for four weeks. Seven of 57 H. pylori isolates were found to have pre-treatment metronidazole resistance. Success, in terms of eradication of H. pylori, was assessed using a one-month post-treatment 14C urea breath test. Successful eradication of H. pylori was achieved in 72% and 79%, respectively, of the metronidazole/De-Nol tablet and metronidazole/De-Nol liquid groups. These figures increased to 87% and 84%, respectively, if the patients whose organisms were known to be metronidazole-sensitive were considered in isolation. H. pylori was successfully eradicated in only one of seven patients with a metronidazole-resistant organism.

  19. Suppressive antibacterial therapy with 0.75% metronidazole vaginal gel to prevent recurrent bacterial vaginosis.

    PubMed

    Sobel, Jack D; Ferris, Daron; Schwebke, Jane; Nyirjesy, Paul; Wiesenfeld, Harold C; Peipert, Jeffrey; Soper, David; Ohmit, Suzanne E; Hillier, Sharon L

    2006-05-01

    Efficacy study of suppressive vaginal metronidazole in reducing recurrent symptomatic episodes of bacterial vaginosis. Multicenter prospective study with initial 10-day open-label metronidazole gel in which asymptomatic responders randomly assigned to receive twice weekly metronidazole vaginal gel or placebo for 16 weeks and off therapy for 12 weeks. Of 157 eligible women with recurrent bacterial vaginosis, 112 of 127 returning evaluable women (88.2%) responded clinically and were randomly assigned. During suppressive therapy, recurrent bacterial vaginosis occurred in 13 women (25.5%) receiving metronidazole and 26 (59.1%) receiving placebo (MITT analysis, relative risk [RR] 0.43, CI = 0.25-0.73, P = .001). During the entire 28-week follow-up, recurrence occurred in 26 (51.0%) on treatment compared with 33 (75%) on placebo (RR 0.68, CI = 0.49-0.93, P = .02). Probability for remaining cured was 70% for metronidazole compared with 39% on placebo, which declined to 34% and 18%, respectively, by 28 weeks follow-up. Adverse effects were uncommon; however, secondary vaginal candidiasis occurred significantly more often in metronidazole-treated women (P = .02). Suppressive therapy with twice-weekly metronidazole gel achieves a significant reduction in the recurrence rate of bacterial vaginosis; however, secondary vaginal candidiasis is common.

  20. Search for novel candidate mutations for metronidazole resistance in Helicobacter pylori using next-generation sequencing.

    PubMed

    Binh, Tran Thanh; Suzuki, Rumiko; Trang, Tran Thi Huyen; Kwon, Dong Hyeon; Yamaoka, Yoshio

    2015-04-01

    Metronidazole resistance is a key factor associated with Helicobacter pylori treatment failure. Although this resistance is mainly associated with mutations in the rdxA and frxA genes, the question of whether metronidazole resistance is caused by the inactivation of frxA alone is still debated. Furthermore, it is unclear whether there are other mutations involved in addition to the two genes that are associated with resistance. A metronidazole-resistant strain was cultured from the metronidazole-susceptible H. pylori strain 26695-1 by exposure to low concentrations of metronidazole. The genome sequences of both susceptible and resistant H. pylori strains were determined by Illumina next-generation sequencing, from which putative candidate resistance mutations were identified. Natural transformation was used to introduce PCR products containing candidate mutations into the susceptible parent strain 26695-1, and the metronidazole MIC was determined for each strain. Mutations in frxA (hp0642), rdxA (hp0954), and rpsU (hp0562) were confirmed by the Sanger method. The mutated sequence in rdxA was successfully transformed into strain 26695-1, and the transformants showed resistance to metronidazole. The transformants containing a single mutation in rdxA showed a low MIC (16 mg/liter), while those containing mutations in both rdxA and frxA showed a higher MIC (48 mg/liter). No transformants containing a single mutation in frxA or rpsU were obtained. Next-generation sequencing was used to identify mutations related to drug resistance. We confirmed that the mutations in rdxA are mainly associated with metronidazole resistance, and mutations in frxA are able to enhance H. pylori resistance only in the presence of rdxA mutations. Moreover, mutations in rpsU may play a role in metronidazole resistance. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  1. Metronidazole-Induced Encephalopathy in Alcoholic Liver Disease: A Diagnostic and Therapeutic Challenge.

    PubMed

    Sonthalia, Nikhil; Pawar, Sunil V; Mohite, Ashok R; Jain, Samit S; Surude, Ravindra G; Rathi, Pravin M; Contractor, Qais

    2016-10-01

    Acute encephalopathy in a patient with alcoholic liver disease (ALD) is a commonly encountered emergency situation occurring most frequently due to liver failure precipitated by varying etiologies. Acute reversible cerebellar ataxia with confusion secondary to prolonged metronidazole use has been reported rarely as a cause of encephalopathy in patients with ALD. We describe a decompensated ALD patient with recurrent pyogenic cholangitis associated with hepatolithiasis who presented to the emergency department with sudden-onset cerebellar ataxia with dysarthria and mental confusion after prolonged use of metronidazole. Magnetic resonance imaging (MRI) of the brain was suggestive of bilateral dentate nuclei hyper intensities on T2 and fluid-attenuated inversion recovery sections seen classically in metronidazole-induced encephalopathy (MIE). Decompensated liver cirrhosis resulted in decreased hepatic clearance and increased cerebrospinal fluid concentration of metronidazole leading to toxicity at a relatively low total cumulative dose of 22 g. Both the clinical symptoms and MRI brain changes were reversed at 7 days and 6 weeks, respectively, after discontinuation of metronidazole. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: A patient with ALD presenting with encephalopathy creates a diagnostic dilemma for the emergency physician regarding whether to continue metronidazole and treat for hepatic encephalopathy or to suspect for MIE and withhold the drug. Failure to timely discontinue metronidazole may worsen the associated hepatic encephalopathy in these patients. Liver cirrhosis patients have higher mean concentration of metronidazole and its metabolite in the blood, making it necessary to keep the cumulative dose of metronidazole to < 20 g in them. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Search for Novel Candidate Mutations for Metronidazole Resistance in Helicobacter pylori Using Next-Generation Sequencing

    PubMed Central

    Binh, Tran Thanh; Suzuki, Rumiko; Trang, Tran Thi Huyen; Kwon, Dong Hyeon

    2015-01-01

    Metronidazole resistance is a key factor associated with Helicobacter pylori treatment failure. Although this resistance is mainly associated with mutations in the rdxA and frxA genes, the question of whether metronidazole resistance is caused by the inactivation of frxA alone is still debated. Furthermore, it is unclear whether there are other mutations involved in addition to the two genes that are associated with resistance. A metronidazole-resistant strain was cultured from the metronidazole-susceptible H. pylori strain 26695-1 by exposure to low concentrations of metronidazole. The genome sequences of both susceptible and resistant H. pylori strains were determined by Illumina next-generation sequencing, from which putative candidate resistance mutations were identified. Natural transformation was used to introduce PCR products containing candidate mutations into the susceptible parent strain 26695-1, and the metronidazole MIC was determined for each strain. Mutations in frxA (hp0642), rdxA (hp0954), and rpsU (hp0562) were confirmed by the Sanger method. The mutated sequence in rdxA was successfully transformed into strain 26695-1, and the transformants showed resistance to metronidazole. The transformants containing a single mutation in rdxA showed a low MIC (16 mg/liter), while those containing mutations in both rdxA and frxA showed a higher MIC (48 mg/liter). No transformants containing a single mutation in frxA or rpsU were obtained. Next-generation sequencing was used to identify mutations related to drug resistance. We confirmed that the mutations in rdxA are mainly associated with metronidazole resistance, and mutations in frxA are able to enhance H. pylori resistance only in the presence of rdxA mutations. Moreover, mutations in rpsU may play a role in metronidazole resistance. PMID:25645832

  3. Randomized pharmacokinetic and drug–drug interaction studies of ceftazidime, avibactam, and metronidazole in healthy subjects

    PubMed Central

    Das, Shampa; Li, Jianguo; Armstrong, Jon; Learoyd, Maria; Edeki, Timi

    2015-01-01

    We assessed pharmacokinetic and safety profiles of ceftazidime–avibactam administered ± metronidazole, and whether drug–drug interactions exist between ceftazidime and avibactam, or ceftazidime-avibactam and metronidazole. The first study (NCT01430910) involved two cohorts of healthy subjects. Cohort 1 received ceftazidime–avibactam (2000–500 mg) as a single infusion or as multiple intravenous infusions over 11 days to evaluate ceftazidime–avibactam pharmacokinetics. Cohort 2 received ceftazidime, avibactam, or ceftazidime–avibactam over 4 days to assess drug–drug interaction between ceftazidime and avibactam. The second study (NCT01534247) assessed interaction between ceftazidime–avibactam and metronidazole in subjects receiving ceftazidime–avibactam (2000–500 mg), metronidazole (500 mg), or metronidazole followed by ceftazidime–avibactam over 4 days. In all studies, subjects received a single-dose on the first and final days, and multiple-doses every 8 h on intervening days. Concentration-time profiles for ceftazidime and avibactam administered as single- or multiple-doses separately or together with/without metronidazole were similar. There was no evidence of time-dependent pharmacokinetics or accumulation. In both interaction studies, 90% confidence intervals for geometric least squares mean ratios of area under the curve and maximum plasma concentrations for each drug were within the predefined interval (80–125%) indicating no drug–drug interaction between ceftazidime and avibactam, or ceftazidime–avibactam and metronidazole. There were no safety concerns. In conclusion, pharmacokinetic parameters and safety of ceftazidime, avibactam, and metronidazole were similar after single and multiple doses with no observed drug–drug interaction between ceftazidime and avibactam, or ceftazidime–avibactam and metronidazole. PMID:26516584

  4. A quantity survey of intravenous administration of metronidazole in its different forms in a tertiary teaching hospital.

    PubMed

    Lee, L L; Rowland, J; Ling, C H Y; Fiakos, E

    2010-08-01

    The aim of this paper is to examine the prescribing patterns and cost of various formulations of metronidazole in a hospital setting over a 3-month period. Oral metronidazole has high bioavailability (98.9%) with peak plasma concentrations averaged at 2.3 h after dosing. Despite the high bioavailability of oral metronidazole, many patients continue to receive metronidazole intravenously when they are suitable for oral preparation. An audit of 120 consecutive patients prescribed metronidazole was conducted at the Liverpool Hospital, NSW, from March to July 2005. There were 65 men and 55 women (age 18-93). Of the 120 patients, 16 were on oral, 1 on rectal and 103 were on intravenous metronidazole. Treatment was initiated based on clinical diagnoses. Potential pathogens were subsequently identified on only 21 occasions. The use of metronidazole as an oral preparation was contraindicated in 27 patients (22.5%) who were nil-by-mouth. Of these, rectally administered metronidazole was contraindicated in only eight patients. The average course of intravenous metronidazole was 8.0 +/- 9.7 days (mean +/- SD). The total number of intravenous metronidazole treatment days was 824. Oral metronidazole would have been possible in 618 out of the 824 days. The estimated cost to administer each dose of oral, suppository and intravenous forms of metronidazole is $A0.11, $A1.34 and $A6.09 respectively. Thus, substantial savings could be achieved if oral metronidazole were to be administered whenever possible. The early use of oral or rectal metronidazole should be encouraged when there are no clinical contraindications.

  5. [Investigation of in vitro metronidazole resistance in the clinical isolates of Trichomonas vaginalis].

    PubMed

    Ertabaklar, Hatice; Yaman Karadam, Senem; Malatyalı, Erdoğan; Ertuğ, Sema

    2016-10-01

    Trichomonas vaginalis, a flagellated, urogenital anaerobic protozoon is reported as an important cause of vaginitis with a global distribution. Although metronidazole is the primary choice of drug for the treatment of trichomoniasis, the presence of resistant isolates from many different countries highlights the need of novel drugs for the treatment. Many studies from Turkey mostly dealing with the in vitro effects of compounds and natural products against T.vaginalis have been reported, however, only one study has been encountered searching the metronidazole resistance in a single T.vaginalis isolate. The aim of this study was to determine the in vitro metronidazole resistance and minimum lethal concentrations (MLCs) of the isolates from symptomatic cases. T.vaginalis strains isolated from vaginal discharge samples of symptomatic women that were sent to Adnan Menderes University Faculty of Medicine, Research and Training Hospital Parasitology Laboratory, between 2009-2014 period, were included in the study. The strains were isolated by the inoculation of samples into trypticase-yeast-maltose medium supplemented with 10% fetal calf serum. A total of 40 T.vaginalis isolates stored by cryopreservation were revived before the experiments. T.vaginalis trophozoites were incubated with different concentrations of metronidazole (200, 100, 50, 25, 12.5, 6.25, 3.12, 1.56 μg/ml) and the viability of cells were examined in both aerobic and anaerobic conditions under phase contrast microscope. Additionally, non-motile isolates were further inoculated into fresh media and viability was checked. The wells containing motile trophozoites after 48 hours of incubation with 15 µg/ml and/or higher metronidazole concentration in anaerobic condition and 75 µg/ml and/or higher metronidazole concentration in aerobic conditions were determined as resistant isolates. Of the 40 T.vaginalis isolates three (7.5%) were resistant to metronidazole. MLC mean values of metronidazole

  6. The role of vancomycin and metronidazole for the treatment of Clostridium difficile-associated diarrhea.

    PubMed

    Tart, Serina B

    2013-10-01

    For the treatment of Clostridium difficile-associated diarrhea (CDAD), metronidazole and vancomycin remain the most commonly used agents. The major advantage of metronidazole is its low cost, while the advantage of oral vancomycin is a more favorable pharmacokinetic profile. The epidemiology and clinical severity of CDAD have changed due to the emergence of a hypervirulent strain (BI/NAP1/027). In 2010, the Infectious Diseases Society of America/Society for Health Care Epidemiology of America expert panel defined severe CDAD and recommended oral vancomycin to treat these patients. Metronidazole remains the preferred agent for treatment of mild to moderate CDAD.

  7. Draft Genome Sequence of a Metronidazole-Susceptible Atopobium vaginae Isolate

    PubMed Central

    Schuyler, Jessica A.; Mordechai, Eli; Adelson, Martin E.; Gygax, Scott E.

    2015-01-01

    We report the draft genome sequence of a vaginal isolate of Atopobium vaginae vaginae (strain 44061), an organism linked to bacterial vaginosis (BV), the most common gynecological infection in the United States. This species is often highly resistant to metronidazole, which is a front-line therapy for BV. Strain 44061 is a metronidazole-susceptible isolate (MIC, 16 µg/ml), and its genome sequence will be useful for comparative studies to elucidate the molecular basis of metronidazole resistance in this species. PMID:26337886

  8. Regional Differences in Metronidazole Resistance and Increasing Clarithromycin Resistance among Helicobacter pylori Isolates from Japan

    PubMed Central

    Kato, Mototsugu; Yamaoka, Yoshio; Kim, Jae J.; Reddy, Rita; Asaka, Masahiro; Kashima, Kei; Osato, Michael S.; El-Zaatari, Fouad A. K.; Graham, David Y.; Kwon, Dong H.

    2000-01-01

    The patterns of antibiotic resistance in Helicobacter pylori were assessed in two different regions in Japan. Overall, prevalences of resistance to metronidazole and clarithromycin were 12.4 and 12.9%, respectively. While there was no difference in clarithromycin resistance, the prevalence of metronidazole resistance was significantly higher in Kyoto (23.8%) than in Sapporo (8.1%). From 1996 to 1999, the prevalence of metronidazole resistance did not change but the prevalence of clarithromycin resistance doubled (from 9.1 to 18.7%). PMID:10898707

  9. Influence of Metronidazole, CO, CO2, and Methanogens on the Fermentative Metabolism of the Anaerobic Fungus Neocallimastix sp. Strain L2

    PubMed Central

    Marvin-Sikkema, Femke D.; Rees, Elizabeth; Kraak, Marjan N.; Gottschal, Jan C.; Prins, Rudolf A.

    1993-01-01

    The effects of metronidazole, CO, methanogens, and CO2 on the fermentation of glucose by the anaerobic fungus Neocallimastix sp. strain L2 were investigated. Both metronidazole and CO caused a shift in the fermentation products from predominantly H2, acetate, and formate to lactate as the major product and caused a lower glucose consumption rate and cell protein yield. An increased lactate dehydrogenase activity and a decreased hydrogenase activity were observed in cells grown under both culture conditions. In metronidazole-grown cells, the amount of hydrogenase protein was decreased compared with the amount in cells grown in the absence of metronidazole. When Neocallimastix sp. strain L2 was cocultured with the methanogenic bacterium Methanobrevibacter smithii, the fermentation pattern changed in the opposite direction: H2 and acetate production increased at the expense of the electron sink products lactate, succinate, and ethanol. A concomitant decrease in the enzyme activities leading to these electron sink products was observed, as well as an increase in the glucose consumption rate and cell protein yield, compared with those of pure cultures of the fungus. Low levels of CO2 in the gas phase resulted in increased H2 and lactate formation and decreased production of formate, acetate, succinate, and ethanol, a decreased glucose consumption rate and cell protein yield, and a decrease in most of the hydrogenosomal enzyme activities. None of the tested culture conditions resulted in changed quantities of hydrogenosomal proteins. The results indicate that manipulation of the pattern of fermentation in Neocallimastix sp. strain L2 results in changes in enzyme activities but not in the proliferation or disappearance of hydrogenosomes. Images PMID:16349022

  10. Novel hybrids of metronidazole and quinolones: synthesis, bioactive evaluation, cytotoxicity, preliminary antimicrobial mechanism and effect of metal ions on their transportation by human serum albumin.

    PubMed

    Cui, Sheng-Feng; Peng, Li-Ping; Zhang, Hui-Zhen; Rasheed, Syed; Vijaya Kumar, Kannekanti; Zhou, Cheng-He

    2014-10-30

    A novel series of hybrids of metronidazole and quinolones as antimicrobial agents were designed and synthesized. Most prepared compounds exhibited good or even stronger antimicrobial activities in comparison with reference drugs. Furthermore, these highly active metronidazole-quinolone hybrids showed appropriate ranges of pKa, log P and aqueous solubility to pharmacokinetic behaviors and no obvious toxicity to A549 and human hepatocyte LO2 cells. Their competitive interactions with metal ions to HSA revealed that the participation of Mg(2+) ion in compound 7d-HSA association could result in a concentration increase of free compound 7d. Molecular modeling and experimental investigation of compound 7d with DNA suggested that possible antibacterial mechanism might be in relation with multiple binding sites between bioactive molecules and topo IV-DNA complex. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  11. Discriminative Dissolution Method for Benzoyl Metronidazole Oral Suspension.

    PubMed

    da Silva, Aline Santos; da Rosa Silva, Carlos Eduardo; Paula, Fávero Reisdorfer; da Silva, Fabiana Ernestina Barcellos

    2016-06-01

    A dissolution method for benzoyl metronidazole (BMZ) oral suspensions was developed and validated using a high-performance liquid chromatography (HPLC) method. After determination of sink conditions, dissolution profiles were evaluated using different dissolution media and agitation speeds. The sample insertion mode in dissolution media was also evaluated. The best conditions were obtained using a paddle, 50 rpm stirring speed, simulated gastric fluid (without pepsin) as the dissolution medium, and sample insertion by a syringe. These conditions were suitable for providing sink conditions and discriminatory power between different formulations. Through the tested conditions, the results can be considered specific, linear, precise, accurate, and robust. The dissolution profiles of five samples were compared using the similarity factor (f 2) and dissolution efficiency. The dissolution kinetics were evaluated and described by the Weibull model. Whereas there is no monograph for this pharmaceutical formulation, the dissolution method proposed can be considered suitable for quality control and dissolution profile comparison of different commercial formulations.

  12. Severe hepatotoxicity associated with the combination of spiramycin plus metronidazole.

    PubMed

    Hussein, Rola; El-Halabi, Mustapha; Ghaith, Ola; Jurdi, Nawaf; Azar, Cecilio; Mansour, Nabil; Sharara, Ala I

    2011-03-01

    Drug-induced liver injury (DILI) is a leading cause of acute liver failure and is the most frequent reason for post-marketing drug withdrawal. The spectrum of liver injury is wide, ranging from mild and subclinical injury, noticeable only on routine biochemical testing, to fulminant liver failure and death. Antibiotics, as a group, are a leading cause of DILI. We herein describe 4 patients who developed moderate to severe hepatotoxicity after exposure to a commercially - available combination of two antibiotics - spiramycin and metronidazole - commonly used for the treatment and prevention of periodontal infections. No other aetiology for liver injury could be identified in all cases. Two patients recovered spontaneously, and two had a more severe course, one responding to corticosteroids and mycophenolate mofetil and the other requiring liver transplantation for subacute massive necrosis.

  13. Influence of Hydroxypropyl Methylcellulose on Metronidazole Crystallinity in Spray-Congealed Polyethylene Glycol Microparticles and Its Impact with Various Additives on Metronidazole Release.

    PubMed

    Oh, Ching Mien; Heng, Paul Wan Sia; Chan, Lai Wah

    2015-12-01

    The purpose of this study was to investigate the effect of a hydrophilic polymer, hydroxypropyl methylcellulose (HPMC), on the crystallinity and drug release of metronidazole (MNZ) in spray-congealed polyethylene glycol (PEG) microparticles and to further modify the drug release using other additives in the formulation. HPMC has been used in many pharmaceutical formulations and processes but to date, it has not been employed as an additive in spray congealing. Crystallinity of a drug is especially important to the development of pharmaceutical products as active pharmaceutical ingredients (APIs) are mostly crystalline in nature. A combination of X-ray diffractometry, differential scanning calorimetry, Raman spectroscopy and Fourier transform-infrared spectroscopy (FT-IR) spectroscopy was employed to investigate the degree of crystallinity and possible solid-state structure of MNZ in the microparticles. The microparticles with HPMC were generally spherical. Spray congealing decreased MNZ crystallinity, and the presence of HPMC reduced the drug crystallinity further. The reduction in MNZ crystallinity was dependent on the concentration of HPMC. Smaller HPMC particles also resulted in a greater percentage reduction in MNZ crystallinity. Appreciable modification to MNZ release could be obtained with HPMC. However, this was largely attributed to the role of HPMC in forming a diffusion barrier. Further modification of drug release from spray-congealed PEG-HPMC microparticles was achieved with the addition of 5% w/w dicalcium phosphate but not with magnesium stearate, methyl cellulose, polyvinylpyrrolidone, silicon dioxide and sodium oleate/citric acid. Dicalcium phosphate facilitated formation of the diffusion barrier.

  14. Synthesis of 1,2,3-Triazolo[4,5-h]quinolone Derivatives with Novel Anti-Microbial Properties against Metronidazole Resistant Helicobacter pylori.

    PubMed

    Abu-Sini, Mohammad; Mayyas, Amal; Al-Karablieh, Nehaya; Darwish, Rula; Al-Hiari, Yusuf; Aburjai, Talal; Arabiyat, Shereen; Abu-Qatouseh, Luay

    2017-05-20

    Helicobacter pylori infection can lead to gastritis, peptic ulcer, and the development of mucosa associated lymphoid tissue (MALT) lymphoma. Treatment and eradication of H. pylori infection can prevent relapse and accelerate the healing of gastric and duodenal ulcers as well as regression of malignancy. Due to the increasing emergence of antibiotic resistance among clinical isolates of H. pylori, alternative approaches using newly discovered antimicrobial agents in combination with the standard antibiotic regimens for the treatment of H. pylori are of major importance. The purpose of the present study was to investigate the effect of newly synthesized 8-amino 7-substituted fluoroquinolone and their correspondent cyclized triazolo derivatives when either alone or combined with metronidazole against metronidazole-resistant H. pylori. Based on standard antimicrobial susceptibility testing methods and checkerboard titration assay, all of the tested compounds showed interesting antimicrobial activity against 12 clinical strains of H. pylori, with best in vitro effect for compounds 4b and 4c. Fractional inhibitory concentration (FIC) mean values showed synergistic pattern in all compounds of Group 5. In addition, additive activities of some of the tested compounds of Group 4 were observed when combined with metronidazole. In contrast, the tested compounds showed no significant urease inhibition activity. These results support the potential of new fluoroquinolone derivatives to be useful in combination with anti-H. pylori drugs in the management of H. pylori-associated diseases.

  15. Comparison of antibacterial effect of photodynamic therapy using indocyanine green (Emundo) with 2% metronidazole and 2% chlorhexidine gel on Porphyromonas gingivalis (an in-vitro study).

    PubMed

    Fekrazad, Reza; Karamifar, Kasra; Bahador, Abbas

    2016-09-01

    The treatment of periodontal disease focuses on eradication or suppression of the pathogenic microbiota within the periodontal pocket. There are some mechanical and chemical ways, and recently antimicrobial photodynamic therapy to eliminate the bacteria. The aim of this in vitro study was to compare the effects of 2% chlorhexidine gel, 2% metronidazole in Orabase, antimicrobial photodynamic therapy with Emundo solution and Emundo solution on P. gingivalis. The antibacterial activities of 2% CHX gel, 2% Metronidazole in Orabase, Emundo+Laser (an infra-red laser diode of 810nm, 300mW, continuous mode radiation, 30s and energy density of 11.5J/cm2), and Emundo against P. gingivalis was tested in vitro using two different methods; (1) Counting CFU/mL and (2) agar diffusion test (ADT). Data of CFU/mL were analyzed using one way ANOVA and Post hoc Tukey test (p<0.05). Data obtained from ADT test were analyzed using Kruskal-Wallis. The percentage of colony-forming units reduction was (99.75, 99.98) in Metronidazole, (99.66, 99.85) in CHX, and (96.68, 96.68) in Laser+Emundo (96.68, 96.68) groups after 24 and 48h, respectively. The amount of bacterial reduction in terms of log10 CFU/mL was decreased in the Metronidazole, CHX, Laser+Emundo and, Emundo groups, respectively after 48h (p<0.05). The inhibition zone radius was decreased in CHX, Metronidazole and, Laser+Emundo, respectively (p<0.05). It can be concluded that within the limitations of this in-vitro study, although photodynamic therapy with Emundo reduced the amount of P. gingivalis significantly, the use of metronidazole 2% in Orabase performed better in terms of reducing the amount of the bacteria. Also, the antibacterial effect of 2% CHX gel on P. gingivalis was significantly more than photodynamic therapy with Emundo. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. EVALUATION OF ALGINATE MICROSPHERES WITH METRONIDAZOLE OBTAINED BY THE SPRAY DRYING TECHNIQUE.

    PubMed

    Szekalska, Marta; Winnicka, Katarzyna; Czajkowska-Kośnik, Anna; Sosnowska, Katarzyna; Amelian, Aleksandra

    2015-01-01

    In the present study, nine formulations (F1-F9) of alginate microspheres with metronidazole were prepared by the spray drying technique with using different drug:polymer ratio (1:2, 1:1, 2:1) and different sodium alginate concentration (1, 2, 3%). The obtained microspheres were characterized for size, morphology, drug loading, (potential and swelling degree. Mucoadhesive properties were examined using texture analyzer and three different models of adhesive layers--gelatin discs, mucin gel and porcine vaginal mucosa. In vitro drug release, mathematical release profile and physical state of microspheres were also evaluated. The obtained results indicate that sodium alginate is a suitable polymer for developing mucoadhesive dosage forms of metronidazole. The optimal formulation F3 (drug:polymer ratio 1:2 and 1% alginate solution) was characterized by the highest metronidazole loading and sustained drug release. The results of this study indicate promising potential of ALG microspheres as alternative dosage forms for metronidazole delivery.

  17. One-Gram, Single-Dose Metronidazole (Flagyl) for Trichomonal Vaginitis.

    ERIC Educational Resources Information Center

    Moore, Jennifer R.

    1979-01-01

    Effective single-dose treatment of trichomonal vaginitis is reported. Large single-dose treatment with metronidazole was found to be effective and avoided the side effects occurring with multidose treatment. (MJB)

  18. One-Gram, Single-Dose Metronidazole (Flagyl) for Trichomonal Vaginitis.

    ERIC Educational Resources Information Center

    Moore, Jennifer R.

    1979-01-01

    Effective single-dose treatment of trichomonal vaginitis is reported. Large single-dose treatment with metronidazole was found to be effective and avoided the side effects occurring with multidose treatment. (MJB)

  19. Metronidazole-resistant clinical isolates of Trichomonas vaginalis have lowered oxygen affinities.

    PubMed

    Yarlett, N; Yarlett, N C; Lloyd, D

    1986-05-01

    Oxygen affinities of metronidazole susceptible and resistant isolates of the parasitic flagellate protozoon Trichomonas vaginalis were determined by mass spectrometric methods. Apparent O2Km values for the respiration of non-proliferating cell suspensions were about 10-fold higher for metronidazole resistant strains than for the susceptible strains C1-NIH or NYH-286. Simultaneous monitoring of hydrogen evolution in the presence of increasing O2 tensions enabled apparent Ki values for H2 to be determined; and this function was independent of metronidazole susceptibility. Apparent O2 affinities of the hydrogenosomal and non-sedimentable fractions were determined for the strains CDC 85 (metronidazole resistant) and C1-NIH, which showed the deficiency in the O2 scavenging capacity by the resistant strain to be associated with the hydrogenosome-containing fraction.

  20. Rifaximin is an effective alternative to metronidazole for the treatment of chronic enteropathy in dogs: a randomised trial.

    PubMed

    Menozzi, Alessandro; Dall'Aglio, Manuel; Quintavalla, Fausto; Dallavalle, Luca; Meucci, Valentina; Bertini, Simone

    2016-10-06

    A clinical trial was conducted in order to assess the efficacy of rifaximin, a broad-spectrum antibiotic with negligible gastrointestinal absorption, in comparison with metronidazole, a commonly employed antimicrobial drug, in dogs with chronic enteropathy. Twenty-four pet dogs were randomly enrolled into two different groups: MET group (10 dogs) and RIF group (14 dogs). Dogs of MET group received metronidazole 15 mg/kg q12h for 21 days by oral route, whereas dogs of RIF group, were given rifaximin 25 mg/kg q12h for 21 days by oral route. Clinical signs of disease were evaluated the day before the beginning of drug administration (D0), and at the end of treatment (D21), by means of Canine IBD Activity Index (CIBDAI). Blood levels of C-reactive protein (CRP) at D0 and D21 were also measured, as another parameter of treatment efficacy. The primary outcome measure of efficacy was the complete remission at D21, defined as a 75 % or greater decrease of CIBDAI; secondary outcome measures were the variation of mean CIBDAI scores, of mean CRP serum levels, and any observed adverse effect from D0 to D21. Treatment with metronidazole or rifaximin greatly improved the clinical signs of disease in each group: in MET group the complete remission was achieved in 8 of 10 dogs (80.0 %), and partial remission in 2 subjects (20.0 %). In RIF group, 12 of 14 dogs showed complete remission (85.7 %), and the remaining 2 dogs were in partial remission (14.3 %). There were also significant decreases of CIBDAI scores (P = 0.002 and P = 0.0002 for MET and RIF, respectively), and CRP levels (P = 0.002 and P = 0.0001 for MET and RIF, respectively) compared to pre-treatment values in both groups. No significant difference, however, was found when comparing MET and RIF groups. No relevant side-effect was reported during the trial with either drugs. The present study showed, for the first time, that oral rifaximin could represent an effective alternative to metronidazole

  1. A new-generation 5-nitroimidazole can induce highly metronidazole-resistant Giardia lamblia in vitro

    PubMed Central

    Dunn, Linda A.; Burgess, Anita G.; Krauer, Kenia G.; Eckmann, Lars; Vanelle, Patrice; Crozet, Maxime D.; Gillin, Frances D.; Upcroft, Peter; Upcroft, Jacqueline A.

    2010-01-01

    The 5-nitroimidazole (NI) compound C17, with a side chain carrying a remote phenyl group in the 2-position of the imidazole ring, is at least 14-fold more active against the gut protozoan parasite Giardia lamblia than the 5-NI drug metronidazole (MTR), with a side chain in the 1-position of the imidazole ring, which is the primary drug for the treatment of giardiasis. Over 10 months, lines resistant to C17 were induced in vitro and were at least 12-fold more resistant to C17 than the parent strains. However, these lines had ID90 values (concentration of drug at which 10% of control parasite ATP levels are detected) for MTR of >200 μM, whilst lines induced to be highly resistant to MTR in vitro have maximum ID90 values around 100 μM (MTR-susceptible isolates typically have an ID90 of 5–12.8 μM). The mechanism of MTR activation in Giardia apparently involves reduction to toxic radicals by the activity of pyruvate:ferredoxin oxidoreductase (PFOR) and the electron acceptor ferredoxin. MTR-resistant Giardia have decreased PFOR activity, which is consistent with decreased activation of MTR in these lines, but C17-resistant lines have normal levels of PFOR. Therefore, an alternative mechanism of resistance in Giardia must account for these super-MTR-resistant cells. PMID:20456926

  2. High-dose vaginal metronidazole for recurrent bacterial vaginosis--a pilot study.

    PubMed

    Aguin, Tina J; Akins, Robert A; Sobel, Jack D

    2014-04-01

    The purpose of this study was to evaluate high-dose intravaginal metronidazole, with or without miconazole, in enhancing cure rates in women with recurrent BV. A total of 43 women with symptomatic recurrent BV were enrolled in a 4-arm study comparing 500 mg versus 750 mg of metronidazole, with or without miconazole, intravaginally for 7 days. Test of cure by saline wet mount and 10% potassium chloride microscopy, pH, Gram stain for Nugent score, and yeast culture were performed 3 times after treatment: 3 to 7 days, 30 to 35 days, and 60 to 70 days. Overall cure rate for the entire group was 92.6% at visit 2, 62.1% at visit 3, and 51.4% at visit 4. At visit 2, there was no difference in cure rates among patients who received metronidazole 750 mg ± miconazole daily (90.5%) compared with metronidazole 500 mg ± miconazole daily (85%). At visit 3, there was a significant improvement in cure rates among patients who received metronidazole 750 mg ± miconazole daily (78.9%) compared with metronidazole 500 mg ± miconazole daily (44.4%) (p < .05). At visit 4, a significant difference in clinical cure rates persisted among patients who received metronidazole 750 mg ± miconazole daily (68.4%) compared with of metronidazole 500 mg ± miconazole daily (33.3%; p < .05). Poor responses (Nugent score > 4 or pH > 4.4) at the first visit alter treatment-predicted recurrence. The addition of miconazole did not enhance BV response rates. Cure rates for BV were high in this refractory cohort and seemed dose dependent.

  3. Clinical relevance of metronidazole and peripheral neuropathy: a systematic review of the literature.

    PubMed

    Goolsby, Tiffany A; Jakeman, Bernadette; Gaynes, Robert P

    2017-09-05

    The objective of this paper was to review and evaluate the literature on metronidazole-associated peripheral neuropathy and determine the relevance in clinical practice. MEDLINE/PubMed, EBSCO, and Google Scholar were searched through February 2017 using the search terms metronidazole and peripheral neuropathy, or polyneuropathy, or paresthesia, or neurotoxicity. Relevant case reports, retrospective studies, surveys, and review articles were included. Bibliographies of all relevant articles were reviewed for additional sources. Overall, metronidazole is generally well tolerated but serious neurotoxicity, including peripheral neuropathy, has been reported. The overall incidence of peripheral neuropathy associated with metronidazole is unknown. Our review found 36 case reports (40 unique patients) of metronidazole-associated peripheral neuropathy with the majority of cases receiving >42 total grams (>4 weeks) of therapy (31 out of 40). In addition, we reviewed 13 clinical studies and found varying rates of peripheral neuropathy from 0-50%. Within these clinical studies, we found a higher incidence of peripheral neuropathy in patients receiving >42 total grams (>4 weeks) of metronidazole compared to those patients receiving ≤ 42 total grams (17.9% vs 1.7%). Nearly all patients had complete resolution of symptoms. In conclusion, peripheral neuropathy is exceedingly rare in patients who receive ≤ 42 total grams of metronidazole. Patients who receive larger total doses may be at higher risk of peripheral neuropathy but most patients have resolution of symptoms after discontinuing therapy. Antimicrobial stewardship programs may consider use of antibiotic combinations that include metronidazole over broad-spectrum alternatives when treating with ≤42 grams of the drug (≤4 weeks). Copyright © 2017. Published by Elsevier B.V.

  4. Pharmacokinetics of metronidazole, tetracycline and bismuth in healthy volunteers after oral administration of compound tablets containing a combination of metronidazole, tetracycline hydrochloride and bismuth oxide.

    PubMed

    Wu, Y; Ding, L; Huang, N-Y; Wen, A-D; Liu, B; Li, W-B

    2015-02-01

    To eradicate Helicobacter pylori in human pylorus and to heal duodenal ulcers, recently, a new formulation of combination tablets containing metronidazole 125 mg, tetracycline hydrochloride 125 mg and bismuth oxide 40 mg has been developed. To investigate the pharmacokinetics of metronidazole, tetracycline and bismuth in healthy Chinese volunteers after oral administration of the test formulation. A one-sequence, 3-period study was conducted in 12 Chinese healthy volunteers (6 male, 6 female). Volunteers each received single low dose (1 tablet) under fed condition in period 1, single high dose (3 tablets) under fasted condition in period 2, and single high dose (3 tablets) and multiple doses (3 tablets at once, 4 times daily for 7 consecutive days) under fed condition in period 3. Blood samples were collected and determined over 48 h in every period. After single high dose administration under fed condition, the C max of metronidazole, tetracycline and bismuth were 6.833 ± 0.742 μg/mL, 0.8513 ± 0.1253 μg/mL and 3.32 ± 1.89 ng/mL, respectively. The C max and AUC 0-48 of metronidazole increased in proportion to the doses within the tested dose range, but tetracycline and bismuth did not. Food caused 10% and 80% decrease of the C max for metronidazole and bismuth, respectively, but did not affect tetracycline. No gender effect was found on the pharmacokinetics of the 3 ingredients. In the steady state, the C av of metronidazole, tetracycline and bismuth were 20.75 ± 3.52 μg/mL, 1.900 ± 0.243 μg/mL and 5.61 ± 1.34 ng/mL, respectively. © Georg Thieme Verlag KG Stuttgart · New York.

  5. Challenges in oral administration of metronidazole dissolved in drinking water to rhesus monkeys (Macaca mulatta).

    PubMed

    Labberton, Linda; Bakker, Jaco; Klomp, Rianne; Langermans, Jan A M; van Geijlswijk, Ingeborg M

    2013-06-01

    Intestinal pathogens such as Entamoeba spp. and Giardia spp. protozoans are not uncommon among rhesus macaques (Macaca mulatta) in research facilities. These infections affect the health of the macaques, potentially causing severe diarrhea, and also pose a risk of zoonotic transmission to human caretakers. Infections must therefore be treated, but no standard treatment for intestinal protozoans in macaques has been developed. Metronidazole is commonly used to treat infections with Giardia spp. and Entamoeba spp. in veterinary medicine, but evidence-based information on effectiveness and dosages for nonhuman primates is lacking, and administration of drugs to nonhuman primates is challenging. The authors designed a study to determine whether oral administration of metronidazole dissolved in drinking water would be successful in rhesus macaques. They monitored daily fluid intake of macaques given water with or without metronidazole and with or without flavored syrup. Metronidazole addition, with or without flavored syrup, resulted in a decrease in fluid intake. Although it was possible to administer metronidazole in drinking water to some macaques, the authors conclude that this strategy is not a practical clinical method because of variation in the amount of water and metronidazole ingested by the macaques.

  6. Intestinal Fatty-Acid Binding Protein and Metronidazole Response in Premature Infants

    PubMed Central

    Sampson, Mario R.; Bloom, Barry T.; Arrieta, Antonio; Capparelli, Edmund; Benjamin, Daniel K.; Smith, P. Brian; Kearns, Gregory L.; van den Anker, John; Cohen-Wolkowiez, Michael

    2014-01-01

    Objectives In premature infants with suspected intra-abdominal infection, biomarkers for treatment response to antimicrobial therapy are lacking. Intestinal fatty acid-binding protein (I-FABP) is specific to the enterocyte and is released in response to intestinal mucosal injury. I-FABP has not been evaluated as a surrogate marker of disease response to antimicrobial therapy. We examined the relationship between metronidazole exposure and urinary I-FABP concentrations in premature infants with suspected intra-abdominal infection. Study design We conducted an intravenous metronidazole pharmacokinetic study, collecting ≤3 urine samples per infant for I-FABP concentration measurements. We analyzed the relationship between I-FABP concentrations and measures of metronidazole exposure and pharmacokinetics, maturational factors, and other covariates. Results Twenty-six samples from 19 premature infants were obtained during metronidazole treatment. When analyzed without regard to presence of necrotic gastrointestinal disease, there were no significant associations between predictor variables and I-FABP concentrations. However, when the sample was limited to premature infants with necrotic gastrointestinal disease, an association was found between average predicted metronidazole concentration and I-FABP concentration (p=0.006). Conclusion While a predictive association between urinary I-FABP and metronidazole systemic exposure was not observed, the data suggest the potential of this endogenous biomarker to serve as a pharmacodynamic surrogate for antimicrobial treatment of serious abdominal infections in neonates and infants. PMID:25318626

  7. Effect of temperature on the metronidazole BSA interaction: Multi-spectroscopic method

    NASA Astrophysics Data System (ADS)

    Chen, Jun; Jiang, Xin Yu; Chen, Xiao Qing; Chen, Yue

    2008-03-01

    The interaction between metronidazole and bovine serum albumin (BSA) was investigated using fluorescence spectroscopy (FS) and resonance light scattering spectroscopy (RLS). The apparent binding constants ( Ka) between metronidazole and BSA were 3.42 × 10 4 (20 °C), 5.78 × 10 4 (30 °C) and 8.23 × 10 4 L mol -1 (40 °C), and the binding sites values ( n) were 1.48 ± 0.03. The experimental results showed that the metronidazole could be inserted into the BSA, quenching the inner fluorescence by forming the metronidazole-BSA complex. The addition of increasing metronidazole to BSA solution leads to the gradual enhancement in RLS intensity, exhibiting the formation of the aggregate in solution. It was found that both static quenching and non-radiation energy transfer were the main reasons for the fluorescence quenching. The entropy change and enthalpy change were positive, which indicated that the interaction of metronidazole and BSA was driven mainly by hydrophobic forces. The process of binding was a spontaneous process in which Gibbs free energy change was negative.

  8. ASSOCIATION OF CALCIUM HYDROXIDE AND METRONIDAZOLE IN THE TREATMENT OF DOG'S TEETH WITH CHRONIC PERIAPICAL LESION

    PubMed Central

    Panzarini, Sônia Regina; Souza, Valdir; Holland, Roberto; Dezan, Eloi

    2006-01-01

    One of the primary objectives of endodontic treatment of teeth with pulp necrosis is the elimination of microorganisms from the root canal system, as effectively as possible, especially in cases with chronic periapical lesions. AIM: The purpose of this study was to analyze the response of the periapical tissue of dogs' teeth with chronic periapical lesions to endodontic treatment performed with utilization of metronidazole, calcium hydroxide, and an association of both as root canal dressings. METHODOLOGY: Forty root canals were submitted to pulpectomy and the root canals were kept exposed to the oral environment for 6 months. Then, they were submitted to biomechanical preparation and divided into 4 study groups with 10 specimens: group I – no root canal dressing; group II – calcium hydroxide; group III – metronidazole; group IV – calcium hydroxide associated to metronidazole. After 15 days, the root canals were filled with Fill Canal sealer. After 90 days, the animals were killed and the especimens processed for histological analysis. RESULTS: Calcium hydroxide dressing provided a significantly better outcome compared to other experimental groups (α = 0.01). Also, the results of the association of metronidazole and calcium hydroxide were similar to those observed for the metronidazole group. The worst results were obtained by the no root canal dressing group. CONCLUSION: The use of metronidazole alone or associated with Calcium hydroxide, did not improve periapical healing when compared to Calcium hydroxide dressing. PMID:19089054

  9. Electrochemical Determination of Metronidazole in Tablet Samples Using Carbon Paste Electrode

    PubMed Central

    Nikodimos, Yosef

    2016-01-01

    Cyclic voltammetric investigation of metronidazole at carbon paste electrode revealed an irreversible reduction peak centered at about −0.4 V. Observed peak potential shift with pH in the range 2.0 to 8.5 indicated the involvement of protons during the reduction of metronidazole, whereas the peak potential shift with scan rate in the range 10–250 mV/s confirmed the irreversibility of the reduction reaction. A better correlation coefficient for the dependence of peak current on the scan rate than on the square root of scan rate indicated an adsorption controlled kinetics. Under the optimized method and solution parameters, an excellent linearity between the reductive peak current and the concentration of metronidazole was observed in the concentration range 1.0 × 10−6 to 5.0 × 10−4 M with a correlation coefficient, method detection limit (based on s = 3σ), and limit of quantification of 0.999, 2.97 × 10−7 M and 9.91 × 10−7 M, respectively. Good recovery results for spiked metronidazole in tablet samples and selective determination of metronidazole in tablet formulations in the presence of selected potential interferents such as rabeprazole, omeprazole, and tinidazole confirmed the potential applicability of the developed method for the determination of metronidazole in real samples like pharmaceutical tablets. PMID:27119041

  10. The mutation of the rdxA gene in metronidazole-resistant Helicobacter pylori clinical isolates.

    PubMed

    Mirzaei, Nasrin; Poursina, Farkhondeh; Moghim, Sharareh; Rahimi, Ebrahim; Safaei, Hajieh Ghasemian

    2014-01-01

    Antibiotic resistance is an increasing problem throughout the developed world, and knowledge about different resistance mechanisms is consequential for efficient treatment of bacterial infections. Although metronidazole has been frequently used in treatment regimens for H. pylori infection, but antibiotic resistance is now a major contributing factor in treatment failure. Nevertheless metronidazole has been greatly used as a critical component of combination therapies for H. pylori infection. This study is trying to describe the mutational mechanisms of metronidazole resistance in H. pylori in our clinical isolates in Isfahanian patients, Iran and compare with the findings of previous studies in world. MIC values of metronidazole for H. pylori strains were determined by E- test. Both rdxA and glmM genes used for confirmation of isolates as H. pylori and then amplification of another rdxA oligonucleotide pair was done. Finally, the six resistant strains were sent to sequencing for other processing and further analysis was done by software. The result of six clinical isolates in comparison with 26695, J99 and 69A as a sensitive and resistant reference strains showed plenty of mutations. No frame shift and nonsense mutation was seen in our clinical isolates. An interesting finding in metronidazole-resistant strains in our study was the detection of one mutation not previously described in the literature in the rdxA gene and this W(209)R substitution presumably plays a role in inducing metronidazole resistance.

  11. The mutation of the rdxA gene in metronidazole-resistant Helicobacter pylori clinical isolates

    PubMed Central

    Mirzaei, Nasrin; Poursina, Farkhondeh; Moghim, Sharareh; Rahimi, Ebrahim; Safaei, Hajieh Ghasemian

    2014-01-01

    Backgrounds: Antibiotic resistance is an increasing problem throughout the developed world, and knowledge about different resistance mechanisms is consequential for efficient treatment of bacterial infections. Although metronidazole has been frequently used in treatment regimens for H. pylori infection, but antibiotic resistance is now a major contributing factor in treatment failure. Nevertheless metronidazole has been greatly used as a critical component of combination therapies for H. pylori infection. Objective: This study is trying to describe the mutational mechanisms of metronidazole resistance in H. pylori in our clinical isolates in Isfahanian patients, Iran and compare with the findings of previous studies in world. Materials and Methods: MIC values of metronidazole for H. pylori strains were determined by E- test. Both rdxA and glmM genes used for confirmation of isolates as H. pylori and then amplification of another rdxA oligonucleotide pair was done. Finally, the six resistant strains were sent to sequencing for other processing and further analysis was done by software. Results: The result of six clinical isolates in comparison with 26695, J99 and 69A as a sensitive and resistant reference strains showed plenty of mutations. No frame shift and nonsense mutation was seen in our clinical isolates. Conclusion: An interesting finding in metronidazole-resistant strains in our study was the detection of one mutation not previously described in the literature in the rdxA gene and this W(209)R substitution presumably plays a role in inducing metronidazole resistance. PMID:24761398

  12. Metronidazole prodrugs: synthesis, physicochemical properties, stability, and ex vivo release studies.

    PubMed

    Mura, Carla; Valenti, Donatella; Floris, Costantino; Sanna, Roberta; De Luca, Maria Antonietta; Fadda, Anna Maria; Loy, Giuseppe

    2011-09-01

    The aim of the present study was to develop a colon targeted delivery system for metronidazole using polymeric prodrug formulation. Two chitosan amide conjugates of metronidazole were prepared by using two different spacers to covalently link the drug to the amino group of the chitosan glucosamine units. Glutaric and succinic hemiesters of metronidazole were thus prepared and then coupled to chitosan to obtain metronidazole-glutaryl- and metronidazole-succinyl-chitosan conjugates. Polymeric prodrugs were characterized by solid state NMR method, namely carbon 13 cross polarization magic angle spinning ((13)C NMR CPMAS). Prodrug stability study was carried out in acid (pH = 1.2) and in alkaline (pH = 7.4) buffers in a thermostatic bath at 37 °C. Drug release from the two prodrugs was studied by incubating each of them with 10% w/v cecal and colonic content of rats. Obtained results showed that both prodrugs were adequately stable in acid environment, while the succinyl conjugate was more stable than the glutaryl one in alkaline buffer. Both the prodrugs released the drug in cecal and colonic content, showing that the two systems could serve as colon specific delivery systems of metronidazole. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  13. High Helicobacter pylori resistance to metronidazole and clarithromycin in Brazilian children and adolescents.

    PubMed

    Ogata, Silvio K; Godoy, Anita P Ortiz; da Silva Patricio, Francy R; Kawakami, Elisabete

    2013-06-01

    The aim of the present study was to assess the primary and secondary resistance of Helicobacter pylori strains to clarithromycin, amoxicillin, furazolidone, tetracycline, and metronidazole, the conventional antibiotics presently used in Brazilian children and adolescents. Seventy-seven consecutive H pylori strains, 71 of 77 strains obtained from patients without previous eradication treatment for H pylori infection, and 6 strains from patients in whom previous eradication treatment had failed. Global rate of resistance was 49.3% (38/77): 40% of strains were resistant to metronidazole, 19.5% to clarithromycin, and 10.4% to amoxicillin. All of the tested H pylori strains were susceptible to furazolidone and tetracycline. Multiple resistance were detected in 18.2% (14/77 patients) of the strains: 6 of 14 (43%) simultaneously resistant to clarithromycin and metronidazole; 5 of 14 (36%) to amoxicillin and metronidazole; 2 of 14 (14%) to amoxicillin, clarithromycin, and metronidazole; and 1 of 14 (7%) to clarithromycin and amoxicillin. The high resistance rate to metronidazole and clarithromycin observed in clinical H pylori isolates can exclude these antimicrobials in empirical eradication treatment in Brazil. Otherwise, furazolidone and tetracycline presented no resistance. Properly assessing the risks and benefits, these 2 antimicrobials and their derivatives could be used in empirical eradication schedules, both associated with amoxicillin, which showed a low resistance rate despite its wide use in pediatric patients.

  14. Resistance of Helicobacter pylori to tetracycline, amoxicillin, clarithromycin and metronidazole in Israeli children and adults.

    PubMed

    Peretz, Avi; Paritsky, Maya; Nasser, Omar; Brodsky, Diana; Glyatman, Tatyana; Segal, Sofia; On, Avi

    2014-08-01

    The aim of this study was to examine Helicobacter pylori-resistance rate to different antibiotics: tetracycline, amoxicillin, clarithromycin and metronidazole, and to compare eradication rates in adults and children in Israel. The study was based on the hypothesis of high-resistance rates to clarithromycin and metronidazole especially in adults and overall low-resistance rates to tetracycline and amoxicillin. One seventy six biopsies from patients with dyspeptic symptoms were cultured of which 100 were from adults (19-79 years) and 76 from children (7-17 years). All positive cultures were examined by Epsilometer test for MIC determination against tetracycline, amoxicillin, clarithromycin and metronidazole. 48.3% (85 out of 176) were H. pylori positive, of which 44% were from adults and 54% from children. Antibiotic resistance was seen in 31 out of 44 (70.5%) for metronidazole, 1 out of 44 (2.3%) for amoxicillin, 10 out of 44 (22.3%) for clarithromycin and 1 out of 44 (2.3%) for tetracycline among adults. Antibiotic resistance was seen in 10 out of 41 (24.4%) for metronidazole, 5 out of 41 (12.2%) for amoxicillin, 10 out of 41 (24.4%) for clarithromycin and 1 out of 41 (2.4%) for tetracycline among children. High rates of H. pylori resistance to metronidazole and clarithromycin was found especially among adults. Therefore, to increase the success rate of anti-H. pylori treatment, other classes of antibiotics need to be considered.

  15. Metronidazole for bacterial vaginosis. A comparison of vaginal gel vs. oral therapy.

    PubMed

    Hanson, J M; McGregor, J A; Hillier, S L; Eschenbach, D A; Kreutner, A K; Galask, R P; Martens, M

    2000-11-01

    To compare the efficacy and safety of 0.75% metronidazole vaginal gel with oral metronidazole for the treatment of bacterial vaginosis (BV). Nonpregnant women with BV were enrolled in a multicenter, randomized, investigator-blind treatment trial. Patients were randomly assigned to either 0.75% metronidazole vaginal gel (5 g twice daily for five days) or oral metronidazole (500 mg twice daily for seven days). Follow-up visits occurred approximately two and five weeks after initiation of therapy. BV was clinically eliminated at the first follow-up visit in 83.7% (36/43, 95% CI 72.3-95.1%) of the intravaginal group and 85.1% (40/47, 95% CI 74.6-95.6%) of the oral group. At the final visit, BV was eliminated in 70.7% (29/41, 95% CI 56.3-85.1%) of the intravaginal group and 71.1% (32/45, 95% CI 57.4-84.8%) of the oral group. Significantly more patients in the oral treatment group (51.8%) reported gastrointestinal complaints as compared to the intravaginal treatment group (32.7%, P = .04). The efficacy of 0.75% metronidazole vaginal gel twice daily for five days in treating BV was similar to that of standard oral metronidazole treatment and was associated with fewer gastrointestinal complaints.

  16. Metronidazole and Hydroxymetronidazole Central Nervous System Distribution: 2. Cerebrospinal Fluid Concentration Measurements in Patients with External Ventricular Drain

    PubMed Central

    Frasca, Denis; Dahyot-Fizelier, Claire; Adier, Christophe; Mimoz, Olivier; Debaene, Bertrand; Couet, William

    2014-01-01

    This study explored metronidazole and hydroxymetronidazole distribution in the cerebrospinal fluid (CSF) of brain-injured patients. Four brain-injured patients with external ventricular drain received 500 mg of metronidazole over 0.5 h every 8 h. CSF and blood samples were collected at steady state over 8 h, and the metronidazole and hydroxymetronidazole concentrations were assayed by high-pressure liquid chromatograph. A noncompartmental analysis was performed. Metronidazole is distributed extensively within CSF, with a mean CSF to unbound plasma AUC0–τ ratio of 86% ± 16%. However, the concentration profiles in CSF were mostly flat compared to the plasma profiles. Hydroxymetronidazole concentrations were much lower than those of metronidazole both in plasma and in CSF, with a corresponding CSF/unbound plasma AUC0–τ ratio of 79% ± 16%. We describe here for the first time in detail the pharmacokinetics of metronidazole and hydroxymetronidazole in CSF. PMID:24277050

  17. Metronidazole and hydroxymetronidazole central nervous system distribution: 2. cerebrospinal fluid concentration measurements in patients with external ventricular drain.

    PubMed

    Frasca, Denis; Dahyot-Fizelier, Claire; Adier, Christophe; Mimoz, Olivier; Debaene, Bertrand; Couet, William; Marchand, Sandrine

    2014-01-01

    This study explored metronidazole and hydroxymetronidazole distribution in the cerebrospinal fluid (CSF) of brain-injured patients. Four brain-injured patients with external ventricular drain received 500 mg of metronidazole over 0.5 h every 8 h. CSF and blood samples were collected at steady state over 8 h, and the metronidazole and hydroxymetronidazole concentrations were assayed by high-pressure liquid chromatograph. A noncompartmental analysis was performed. Metronidazole is distributed extensively within CSF, with a mean CSF to unbound plasma AUC0-τ ratio of 86% ± 16%. However, the concentration profiles in CSF were mostly flat compared to the plasma profiles. Hydroxymetronidazole concentrations were much lower than those of metronidazole both in plasma and in CSF, with a corresponding CSF/unbound plasma AUC0-τ ratio of 79% ± 16%. We describe here for the first time in detail the pharmacokinetics of metronidazole and hydroxymetronidazole in CSF.

  18. Removal of the antibiotic metronidazole by adsorption on various carbon materials from aqueous phase.

    PubMed

    Carrales-Alvarado, D H; Ocampo-Pérez, R; Leyva-Ramos, R; Rivera-Utrilla, J

    2014-12-15

    The adsorption of the antibiotic metronidazole (MNZ) on activated carbon (F400), activated carbon cloth (ACF), mesoporous activated carbon (CMK-3), and carbon nanotubes (MWCNT) was investigated in this work. The effect of the adsorbent-adsorbate interactions as well as the operating conditions (ionic strength, solution pH, temperature, chemical modification of the adsorbents by HNO3 treatment, and water matrix) on the adsorption capacity were analyzed to substantiate the adsorption mechanism. The adsorption capacity markedly varied as function of the carbon material, decreasing in the following order: F400>ACF>F400-HNO3>CMK-3>MWCNT>MWCNT-HNO3, and depended not only on their surface area and pore size distribution, but also on their chemical nature. The adsorption of MNZ was influenced by the solution pH, but was not significantly affected by the ionic strength and temperature. The adsorption of MNZ was enhanced when the MNZ solutions were prepared using wastewater. Therefore, the electrolytes present in the wastewater cooperated rather than competed with the MNZ molecules for the adsorption sites. Desorption equilibrium data of MNZ on all carbon materials demonstrated that the adsorption was reversible corroborating the weakness of the adsorbent-adsorbate interactions.

  19. Study on treatment of bacterial vaginosis with oral administration of metronidazole or cefdinir.

    PubMed

    Mikamo, H; Izumi, K; Ito, K; Katoh, N; Watanabe, K; Ueno, K; Tamaya, T

    1994-01-01

    Bacterial vaginosis (BV) is considered to be one of the most common vaginal infections in women. Fifteen symptomatic women with BV were enrolled in this study. Ten patients with the diagnosis of BV were treated with 10 days oral administration of metronidazole (MTN), 500 mg twice a day, and five patients with cefdinir (CFDN), 300 mg three times a day. In the MTN therapy, the rate of abnormal vaginal discharge subjectively decreased from 100 to 60%, the rate of abnormal vaginal discharges objectively decreased from 100 to 20%, the rate of positive amine tests decreased from 100 to 20%, the rate of genital malodor and abnormal pH of vaginal discharges decreased substantially from 100 to 10%, and the rate of the presence of clue cells also decreased notably from 90 to 10%. However, in the CFDN therapy, none of these factors improved. With respect to susceptibility to CFDN and MTN, CFDN demonstrated good antibacterial activity against almost all bacteria isolated except Gardnerella vaginalis. On the other hand, MTN demonstrated excellent activity against anaerobic bacteria except Peptostreptococcus spp., and had no antibacterial activity against aerobic bacteria. Since the therapeutic effect of MTN in BV appeared to be better than that of CFDN, anaerobes may play a major role in causing clinical symptoms in patients with BV.

  20. [Pharmacokinetics/pharmacodinamic (PK/PD) evaluation of a short course of oral administration of metronidazole for the management of infections caused by Bacteroides fragilis].

    PubMed

    Morales-León, Felipe; von Plessing-Rossel, Carlos; Villa-Zapata, Lorenzo; Fernández-Rocca, Pola; Sanhueza-Sanhueza, Cindy; Bello-Toledo, Helia; Mella-Montecinos, Sergio

    2015-04-01

    Metronidazole is the antibiotic of choice for the management of infections caused by anaerobes. Its administration requires multiple daily doses causing increased medication errors. Due to its high post-antibiotic effect and rapid concentration-dependent bactericidal activity, administration of this antibiotic in an extended dosing interval would achieve PK/PD parameters effectively. To assess the probability of achieving effective PK/PD relationship with the administration of 1,000 mg every 24 hours of metronidazole for Bacteroides fragilis infections. A clinical trial was conducted in a group of volunteers who received a single oral dose of 500 or 1,000 mg of metronidazole. Determinations of values of Cmax, t max, and AUCC0-24 h. determined using the trapezoidal method, were obtained for a Markov simulation that would allow for determining the likelihood of achieving a AUC0-24 h/MIC ratio above 70 for infections caused by susceptible B. fragilis. Cmax (24,03 ± 6,89 mg/L) and t max (1,20 ± 0.80 hrs) and the value of AUC0-24 h (241.91 ± 48.14 mg * h/L) were determined. The probability of obtaining a AUC0-24 h/MIC ratio greater than 70 was greater than 99%. From a pharmacokinetic perspective, with the administration of a daily dose of 1,000 mg of metronidazole, it is possible to achieve a therapeutic goal of AUC0-24 h/MIC ratio above 70 for the treatment of anaerobic infections.

  1. A new fluorescent probe with a large turn-on signal for imaging nitroreductase in tumor cells and tissues by two-photon microscopy.

    PubMed

    Liu, Zhan-Rong; Tang, Yonghe; Xu, An; Lin, Weiying

    2017-03-15

    Hypoxia is the important characteristic of solid tumors, and it may cause the bioactivity of nitroreductase (NTR) to display an elevated level. Hence, the development of effective monitoring methods of NTR in living systems is of great importance for detecting the occurrence and progress of tumors. Toward this goal, a novel two-photon fluorescence turn-on NTR probe GCTPOC-HY, based on the two-photon platform GCTPOC and the NTR recognition site p-nitrobenzyl ether, is designed and synthesized. The probe GCTPOC-HY exhibits eminent properties such as high sensitivity and selectivity, highly stable photo-stability, and low cytotoxicity. Besides, the probe responds to 1.5μg/mL NTR with a 130-fold fluorescence enhancement, which is larger than the reported two-photon fluorescent NTR probes. Moreover, the probe GCTPOC-HY is suitable for fluorescence imaging of NTR in living cells by one- and two-photon modes. Importantly, the probe GCTPOC-HY is successfully applied to monitor NTR in the tumor tissues with a significant fluorescence signal and a penetration depth of 70µm by using two-photon microscopy. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Doxycycline, metronidazole and isotretinoin: Do they modify microRNA/mRNA expression profiles and function in murine T-cells?

    PubMed Central

    Becker, Eugenia; Bengs, Susan; Aluri, Sirisha; Opitz, Lennart; Atrott, Kirstin; Stanzel, Claudia; Castro, Pedro A. Ruiz; Rogler, Gerhard; Frey-Wagner, Isabelle

    2016-01-01

    Inflammatory bowel disease (IBD) may develop due to an inflammatory response to commensal gut microbiota triggered by environmental factors in a genetically susceptible host. Isotretinoin (acne therapy) has been inconsistently associated with IBD onset and flares but prior treatment with antibiotics, also associated with IBD development, complicates the confirmation of this association. Here we studied in mice whether doxycycline, metronidazole or isotretinoin induce epigenetic modifications, and consequently change T-cell mRNA expression and/or function directly after treatment and after a 4 week recovery period. Isotretinoin induced IL-10 signaling in Tregs and naive T-cells directly after treatment and reduced effector T-cell proliferation alone and in co-culture with Tregs. Metronidazole activated processes associated with anti-inflammatory pathways in both T-cell subsets directly after the treatment period whereas doxycycline induced an immediate pro-inflammatory expression profile that resolved after the recovery period. Long-term changes indicated an inhibition of proliferation by doxycycline and induction of beneficial immune and metabolic pathways by metronidazole. Persistent alterations in microRNA and mRNA expression profiles after the recovery period indicate that all three medications may induce long-term epigenetic modifications in both T-cell subsets. Yet, our data do not support the induction of a long-term pro-inflammatory phenotype in murine Tregs and naive T-cells. PMID:27853192

  3. Metronidazole decreases viability of DLD-1 colorectal cancer cell line.

    PubMed

    Sadowska, Anna; Krętowski, Rafał; Szynaka, Beata; Cechowska-Pasko, Marzanna; Car, Halina

    2013-10-01

    The aim of our study was to evaluate the impact of metronidazole (MTZ) on DLD-1 colorectal cancer cell (CRC) line. Toxicity of MTZ was determined by MTT test. Cells were incubated with MTZ used in different concentrations for 24, 48, and 72 hours. The effect of MTZ on DNA synthesis was measured as [3H]-thymidine incorporation. The morphological changes in human DLD-1 cell line were defined by transmission electron microscope OPTON 900. The influence of MTZ on the apoptosis of DLD-1 cell lines was detected by flow cytometry and fluorescence microscopy, while cell concentration, volume, and diameter were displayed by Scepter Cell Counter from Millipore. Our results show that cell viability was diminished in all experimental groups in comparison with the control, and the differences were statistically significant. We did not find any significant differences in [3H]-thymidine incorporation in all experimental groups and times of observation. Cytofluorimetric assays demonstrated a statistically significant increase of apoptotic rate in MTZ concentrations 10 and 50 μg/mL after 24 hours; 0.1, 10, 50, and 250 μg/mL after 48 hours; and in all concentrations after 72 hours compared with control groups. In the ultrastructural studies, necrotic or apoptotic cells were occasionally seen. In conclusion, MTZ affects human CRC cell line viability. The reduction of cell viability was consistent with the apoptotic test.

  4. Vancomycin, metronidazole, or tolevamer for Clostridium difficile infection: results from two multinational, randomized, controlled trials.

    PubMed

    Johnson, Stuart; Louie, Thomas J; Gerding, Dale N; Cornely, Oliver A; Chasan-Taber, Scott; Fitts, David; Gelone, Steven P; Broom, Colin; Davidson, David M

    2014-08-01

    Clostridium difficile infection (CDI) is a common complication of antibiotic therapy that is treated with antibiotics, contributing to ongoing disruption of the colonic microbiota and CDI recurrence. Two multinational trials were conducted to compare the efficacy of tolevamer, a nonantibiotic, toxin-binding polymer, with vancomycin and metronidazole. Patients with CDI were randomly assigned in a 2:1:1 ratio to oral tolevamer 9 g (loading dose) followed by 3 g every 8 hours for 14 days, vancomycin 125 mg every 6 hours for 10 days, or metronidazole 375 mg every 6 hours for 10 days. The primary endpoint was clinical success, defined as resolution of diarrhea and absence of severe abdominal discomfort for more than 2 consecutive days including day 10. In a pooled analysis, 563 patients received tolevamer, 289 received metronidazole, and 266 received vancomycin. Clinical success of tolevamer was inferior to both metronidazole and vancomycin (P < .001), and metronidazole was inferior to vancomycin (P = .02; 44.2% [n = 534], 72.7% [n = 278], and 81.1% [n = 259], respectively). Clinical success in patients with severe CDI who received metronidazole was 66.3% compared with vancomycin, which was 78.5%. (P = .059). A post-hoc multivariate analysis that excluded tolevamer found 3 factors that were strongly associated with clinical success: vancomycin treatment, treatment-naive status, and mild or moderate CDI severity. Adverse events were similar among the treatment groups. Tolevamer was inferior to antibiotic treatment of CDI, and metronidazole was inferior to vancomycin. Trial Registration. clinicaltrials.gov NCT00106509 and NCT00196794. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  5. Evaluation of mechanical and rheological properties of metronidazole gel as local delivery system.

    PubMed

    Jelvehgari, Mitra; Montazam, Hassan

    2011-06-01

    Rosacea is a chronic multifactorial vascular skin disorder that affects about 10 percent of the general population. Metronidazole is an effective antibiotic in the treatment of moderate-to severe rosacea. Metronidazole is a suitable drug in cases of resistance to tetracycline or erythromycin, but it has also been shown that oral metronidazole may increase the side effects (e.g., peripheral neuropathy). Oral metronidazole should not be used for more than three months, and hence topical metronidazole gel is the best therapeutic choice in rosacea (especially during pregnancy). This study examined the mechanical (adhesiveness, cohesiveness, extrudability, spreadability, homogeneity) and rheological (viscosity), skin irritant and drug release properties of different metronidazole gel formulations that contain anionic emulsifying wax, glycerin and lactic acid in different proportions. The release studies were conducted using Franz diffusion cells and Silastic membrane as a barrier. The results indicated that gel compressibility, hardness, and adhesiveness, are the factors that influence the ease of gel removal from the container, ease of gel application onto the mucosal membrane, and gel bioadhesion. The findings showed that there exists a strong negative correlation between the spreadability of a formulation and its cohesiveness, the spreadability of a formulation is inversely proportional to its cohesiveness. However, sorbitol solution (70%) concentration was not significantly correlated with drug release. In addition, drug release was significantly reduced as the concentration of anionic emulsifying wax increased and the concentration of lactic acid decreased. The maximum metronidazole release was achieved at a pH of 4-6. Data obtained from in vitro release studies were fitted to various kinetic models and high correlation was obtained in the Higuchi and first order models. The results showed that all the gel formulations showed good extrudability, viscosity

  6. An in vitro metronidazole susceptibility test for trichomoniasis using the InPouch TV test.

    PubMed

    Borchardt, K A; Li, Z; Zhang, M Z; Shing, H

    1996-04-01

    An efficient anaerobic culture system, the InPouch TV test, was used to determine the susceptibility of Trichomonas vaginalis to metronidazole. Glacial acetic acid was employed as a solvent for metronidazole. T vaginalis isolates were cultured from 16 symptomatic female patients. The 11 who responded to oral metronidazole, 250 mg tid for 7 days, were considered as having sensitive trichomonads; the 5 who remained infected after treatment were considered to have resistant organisms. All isolates were cultured for minimum lethal concentrations (MLC). Metronidazole was added to a series of pouches; two-fold dilution of the most concentrated was 50 micrograms/ml and the least was 0.4 micrograms/ml. The inoculum of viable trichomonads was 1 x 105/ml in each pouch. Pouches were incubated at 37 degrees C for 48 h, examined microscopically for motile trichomonads, and then 0.5 ml was subcultured to drug free pouches. After 5 days incubation at 37 degrees C, each subculture and culture were examined microscopically for viable trichomonads. Eleven isolates of T vaginalis from patients responding to metronidazole treatment had MLC between 0.4 to 3.1 micrograms/ml. The MLC from the 5 treatment failure patients were between 12.5 to 50 micrograms/ml. For the 16 patients in this study, the MLC values determined with the InPouch TV test differentiated between infection caused by metronidazole sensitive and resistant trichomonads. The mean MLC of clinically resistant isolates was approximately eleven fold higher than the mean MLC of clinically sensitive isolates (15 micrograms/ml vs 1.32 micrograms/ml). There was a significant difference between clinically resistant and sensitive isolates (t = 5.47, p < 0.0005). This study suggests that the InPouch TV test could be used for distinguishing between metronidazole resistant and sensitive isolates.

  7. Genotoxicity Revaluation of Three Commercial Nitroheterocyclic Drugs: Nifurtimox, Benznidazole, and Metronidazole

    PubMed Central

    Buschini, Annamaria; Ferrarini, Lisa; Franzoni, Susanna; Galati, Serena; Lazzaretti, Mirca; Mussi, Francesca; Northfleet de Albuquerque, Cristina; Maria Araújo Domingues Zucchi, Tânia; Poli, Paola

    2009-01-01

    Nitroheterocyclic compounds are widely used as therapeutic agents against a variety of protozoan and bacterial infections. However, the literature on these compounds, suspected of being carcinogens, is widely controversial. In this study, cytotoxic and genotoxic potential of three drugs, Nifurtimox (NFX), Benznidazole (BNZ), and Metronidazole (MTZ) was re-evaluated by different assays. Only NFX reduces survival rate in actively proliferating cells. The compounds are more active for base-pair substitution than frameshift induction in Salmonella; NFX and BNZ are more mutagenic than MTZ; they are widely dependent from nitroreduction whereas microsomal fraction S9 weakly affects the mutagenic potential. Comet assay detects BNZ- and NFX-induced DNA damage at doses in the range of therapeutically treated patient plasma concentration; BNZ seems to mainly act through ROS generation whereas a dose-dependent mechanism of DNA damaging is suggested for NFX. The lack of effects on mammalian cells for MTZ is confirmed also in MN assay whereas MN induction is observed for NFX and BNZ. The effects of MTZ, that shows comparatively low reduction potential, seem to be strictly dependent on anaerobic/hypoxic conditions. Both NFX and BNZ may not only lead to cellular damage of the infective agent but also interact with the DNA of mammalian cells. PMID:20981287

  8. Design, synthesis and molecular docking of salicylic acid derivatives containing metronidazole as a new class of antimicrobial agents.

    PubMed

    Guo, Zhi-Hua; Yin, Yong; Wang, Cong; Wang, Peng-Fei; Zhang, Xing-Tao; Wang, Zhong-Chang; Zhu, Hai-Liang

    2015-09-15

    A series of novel salicylic acid derivatives containing metronidazole as Staphylococcus aureus Tyrosyl-tRNA synthetase (TyrRS) inhibitors have been synthesized and evaluated their biology activities as potential antibacterial agents. Among these compounds, compound 5r exhibited the most potent antibacterial activity against Gram-positive (S. aureus ATCC 6538 and Bacillus subtilis ATCC 6633) and Gram-negative (Escherichia coli ATCC 35218 and Pseudomonas aeruginosa ATCC 13525) with MICs of 0.39-1.57 μg/mL and showed the most potent S. aureus Tyrosyl-tRNA synthetase inhibitory with 2.3 μM. Docking simulation was performed to insert compound 5r into the crystal structure of S. aureus Tyrosyl-tRNA synthetase active site to determine the probable binding model. These results suggested that compound 5r may be a promising antibacterial agent.

  9. A study on Nim expression in Bacteroides fragilis

    PubMed Central

    Leitsch, David; Sóki, József; Kolarich, Daniel; Urbán, Edit; Nagy, Elisabeth

    2016-01-01

    Summary Members of the genus Bacteroides, mainly Bacteroides fragilis, can cause severe disease in man, especially after intestinal perforation in the course of abdominal surgery. Treatment is based on a small number of antibiotics, including metronidazole which has proved to be highly reliable throughout the last 40 to 50 years. Nevertheless, metronidazole resistance does occur in Bacteroides and has been mainly attributed to Nim proteins, a class of proteins with suggested nitroreductase function. Despite the potentially high importance of Nim proteins for human health, information on the expression of nim genes in Bacteroides fragilis is still lacking. It was the aim of this study to demonstrate expression of nim genes in B. fragilis at the protein level and, further, to correlate the level of Nim levels with the level of metronidazole resistance. By application of two-dimensional gel electrophoresis, Nim proteins could be readily identified in nim-positive strains but their levels were not elevated to a relevant extent after induction of resistance to high doses of metronidazole. Thus, the presented data do not provide evidence for Nim proteins acting as nitroreductases using metronidazole as a substrate because no correlation of Nim levels and level of resistance could be observed. Further, no evidence was found that Nim proteins protect B. fragilis from metronidazole by sequestering activated metronidazole. PMID:24448511

  10. Exposure to Metronidazole In Vivo Readily Induces Resistance in Helicobacter pylori and Reduces the Efficacy of Eradication Therapy in Mice

    PubMed Central

    Jenks, Peter J.; Labigne, Agnes; Ferrero, Richard L.

    1999-01-01

    The Helicobacter pylori SS1 mouse model was used to characterize the development of resistance in H. pylori after treatment with metronidazole monotherapy and to examine the effect of prior exposure to metronidazole on the efficacy of a metronidazole-containing eradication regimen. Mice colonized with the metronidazole-sensitive H. pylori SS1 strain were treated for 7 days with either peptone trypsin broth or the mouse equivalent of 400 mg of metronidazole once a day or three times per day (TID). In a separate experiment, H. pylori-infected mice were administered either peptone trypsin broth or the mouse equivalent of 400 mg of metronidazole TID for 7 days, followed 1 month later by either peptone trypsin broth or the mouse equivalent of 20 mg of omeprazole, 250 mg of clarithromycin, and 400 mg of metronidazole twice a day for 7 days. At least 1 month after the completion of treatment, the mice were sacrificed and their stomachs were cultured for H. pylori. The susceptibilities of isolates to metronidazole were assessed by agar dilution determination of the MICs. Mixed populations of metronidazole-resistant and -sensitive strains were isolated from 70% of mice treated with 400 mg of metronidazole TID. The ratio of resistant to sensitive strains was 1:100, and the MICs for the resistant strains varied from 8 to 64 μg/ml. In the second experiment, H. pylori was eradicated from 70% of mice treated with eradication therapy alone, compared to 25% of mice pretreated with metronidazole (P < 0.01). Mice still infected after treatment with metronidazole and eradication therapy contained mixed populations of metronidazole-resistant and -sensitive isolates in a ratio of 1:25. These results demonstrate that H. pylori readily acquires resistance to metronidazole in vivo and that prior exposure of the organism to metronidazole is associated with failure of eradication therapy. H. pylori-infected mice provide a suitable model for the study of resistance mechanisms in H. pylori

  11. Randomized, double-blind, comparative study of oral metronidazole and tinidazole in treatment of bacterial vaginosis.

    PubMed

    Raja, Indu M; Basavareddy, Asha; Mukherjee, Deepali; Meher, Bikash Ranjan

    2016-01-01

    To compare the efficacy and tolerability of oral metronidazole and tinidazole in patients with bacterial vaginosis (BV) using Amsel's criteria. This was a randomized double-blind study, conducted by the Departments of Pharmacology and Gynecology of a tertiary care teaching hospital. Patients diagnosed with BV received either tablet metronidazole 500 mg twice daily for 5 days or tablet tinidazole 500 mg once daily + one placebo for 5 days and instructed to come for follow-up at the 1(st) week and 4(th) week. They were categorized as cured, partially cured, and not cured based on Amsel's criteria at the end of the study and compared between two groups using Chi-square test. A total 120 women were enrolled in the study, of which 114 completed the study. The treatment arms were comparable. The cure rate with low-dose tinidazole was significantly more compared to metronidazole at 4(th) week (P = 0.0013), but not at 1(st) week (P = 0.242). The adverse drug reactions were less with tinidazole compared to metronidazole. Tinidazole at lower dose offers a better efficacy than metronidazole in long-term cure rates and in preventing relapses with better side effect profile.

  12. Combinatorial effects of amoxicillin and metronidazole on selected periodontal bacteria and whole plaque samples.

    PubMed

    Kulik Kunz, Eva M; Lenkeit, Krystyna; Waltimo, Tuomas; Weiger, Roland; Walter, Clemens

    2014-06-01

    The aim of the present study was to analyze in vitro the combinatorial effects of the antibiotic combination of amoxicillin plus metronidazole on subgingival bacterial isolates. Aggregatibacter (Actinobacillus) actinomycetemcomitans, Prevotella intermedia/nigrescens, Fusobacterium nucleatum and Eikenella corrodens from our strain collection and subgingival bacteria isolated from patients with periodontitis were tested for their susceptibility to amoxicillin and metronidazole using the Etest. The fractional inhibitory concentration index (FICI), which is commonly used to describe drug interactions, was calculated. Synergy, i.e. FICI values ≤ 0.5, between amoxicillin and metronidazole was shown for two A. actinomycetemcomitans (FICI: 0.3), two F. nucleatum (FICI: 0.3 and 0.5, respectively) and one E. corrodens (FICI: 0.4) isolates. Indifference, i.e. FIC indices of >0.5 but ≤4, occurred for other isolates and the 14 P. intermedia/nigrescens strains tested. Microorganisms resistant to either amoxicillin or metronidazole were detected in all samples by Etest. Combinatorial effects occur between amoxicillin and metronidazole on some strains of A. actinomycetemcomitans, F. nucleatum and E. corrodens. Synergy was shown for a few strains only. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Evaluation of metronidazole-loaded poly(3-hydroxybutyrate) membranes to potential application in periodontitis treatment.

    PubMed

    da Silva, Marcio A C; Oliveira, Renata N; Mendonça, Roberta Helena; Lourenço, Talita G B; Colombo, Ana Paula V; Tanaka, Marcelo N; Tude, Elena M O; da Costa, Marysilvia F; Thiré, Rossana Mara S M

    2016-01-01

    Guided tissue regeneration is a technique used for periodontium reconstruction. This technique uses barrier membranes, which prevent epithelial growth in the wound site and may also be used to release antibiotics, to protect the wound against opportunistic infections. Periodontal poly(3-hydroxybutyrate) membranes containing metronidazole (a drug used to help in infection control) were produced and characterized. The kinetic mechanism of the metronidazole delivery of leached and nonleached membrane as well as its cytotoxicity and structural integrity were evaluated. Poly(3-hydroxybutyrate) membranes containing 0.5-2 wt % of the drug and 20 wt % of the plasticizer were manufactured via compression molding. Based on morphological analysis, membranes loaded with 2% metronidazole were considered for detailed studies. The results revealed that metronidazole delivery by the leached membranes seemed to follow the Fick's law. Membranes were noncytotoxic. The amount of metronidazole delivered was in the range of the minimal inhibitory concentration for Porphyromonas gingivalis, and the membranes inhibited the proliferation of these bacteria. Besides, they maintained their mechanical resistance after 30 days of immersion in phosphate buffer at pH 7.4. © 2015 Wiley Periodicals, Inc.

  14. Randomized, double-blind, comparative study of oral metronidazole and tinidazole in treatment of bacterial vaginosis

    PubMed Central

    Raja, Indu M.; Basavareddy, Asha; Mukherjee, Deepali; Meher, Bikash Ranjan

    2016-01-01

    Objective: To compare the efficacy and tolerability of oral metronidazole and tinidazole in patients with bacterial vaginosis (BV) using Amsel's criteria. Patients and Methods: This was a randomized double-blind study, conducted by the Departments of Pharmacology and Gynecology of a tertiary care teaching hospital. Patients diagnosed with BV received either tablet metronidazole 500 mg twice daily for 5 days or tablet tinidazole 500 mg once daily + one placebo for 5 days and instructed to come for follow-up at the 1st week and 4th week. They were categorized as cured, partially cured, and not cured based on Amsel's criteria at the end of the study and compared between two groups using Chi-square test. Results: A total 120 women were enrolled in the study, of which 114 completed the study. The treatment arms were comparable. The cure rate with low-dose tinidazole was significantly more compared to metronidazole at 4th week (P = 0.0013), but not at 1st week (P = 0.242). The adverse drug reactions were less with tinidazole compared to metronidazole. Conclusion: Tinidazole at lower dose offers a better efficacy than metronidazole in long-term cure rates and in preventing relapses with better side effect profile. PMID:28066102

  15. Effects of mesocaval shunt on the pharmacokinetics of metronidazole in young rats.

    PubMed

    Guillé, Beatriz E Perez; Alvarez, Fernando Villegas; Toledo López, Alejandra R; Bravo-Luna, Miguel A Jiménez; Soriano-Rosales, Rosa E; Lares-Asseff, Ismael; Arrellin, Gerardo; Guillé, Maria G Pérez

    2005-01-01

    Prophylactic and therapeutic management of portosystemic encephalopathies is based on protein restriction in the diet, and the use of lactulose and antibiotics such as metronidazole. These actions intend to reduce the main source of intestinal ammonia production and release into the systemic circulation. The aim of this study was to evaluate the medium-term effects of mesocaval shunt on the pharmacokinetics of metronidazole in rats with healthy livers. Male Lewis rats were divided into two groups. The first group was subjected to mesocaval shunt (MCS) and the other employed as a control. The following tests were carried out in both groups: metronidazole pharmacokinetics, determination of ALT, AST, albumin, urea and ammonium, liver weight and histomorphology. A loss in body and liver weight was registered in rats subjected to MCS. AST levels also increased compared to controls. Significant differences in almost all pharmacokinetic parameters were detected between MCS and control rats, especially in Kel, AUC and Cmax. Modifications in metronidazole pharmacokinetics and liver weight changes without microstructural modification secondary to MCS were found. We suggest that individual drug-monitoring and pharmacokinetic analysis must be carried out in metronidazole medicated patients with modifications in portal circulation with or with out macro or micro liver structural alterations.

  16. [MRI and SPECT findings in a case of metronidazole-induced reversible acute cerebellar ataxia].

    PubMed

    Takase, Kei-ichiro; Santa, Yo; Ohta, Sumio; Yoshimura, Takeo

    2005-05-01

    A 69-year-old man was referred to our department because of acute onset nausea, vomiting, dysphagia, dysarthria and gait disturbance. He had a 50-day-history of amebic dysentery and had been treated with 1,500 mg metronidazole per day. Neurological examination revealed dysphagia, ataxic speech, ataxia of the left extremities and the trunk, and hyperactive deep tendon reflexes in all extremities. Sensory impairment of all modalities was apparent in a glove and stocking pattern, with mild paresthesia. Brain MRI showed T2 high signal lesions in the bilateral cerebellar dentate nuclei, more markedly on the left. On brain SPECT, obvious low blood perfusion was observed in the left cerebellar hemisphere. These findings well explained the ataxia of the left limbs. One month after discontinuing metronidazole, the cerebellar ataxia, dysphagia and MRI abnormalities completely cleared. Therefore, central nervous system damage induced by metronidazole is considered reversible. In spite of the presence of the MRI lesion in the right dentate nucleus, the patient had no ataxia of the right extremities and there was no hypoperfusion in the right cerebellar hemisphere. Thus, metronidazole does not appear to have a direct neurotoxic effect on the central nervous system. On the other hand, nerve conduction studies showed axonal polyneuropathy, which was not improved one month after cessation of the drug; thus metronidazole seems to exert more damage on peripheral nerves.

  17. Liquid chromatographic assay for metronidazole and tinidazole: pharmacokinetic and metabolic studies in human subjects.

    PubMed Central

    Nilsson-Ehle, I; Ursing, B; Nilsson-Ehle, P

    1981-01-01

    We developed methods for measuring metronidazole, its two major metabolites, and tinidazole in serum and urine. After treatment of each sample with an equal volume of 5% perchloric acid, the drugs were separated by reverse-phase high-pressure liquid chromatography (retention times, 6 to 18 min). Quantitation was based on spectrometry at 320 nm. These assays were sensitive, rapid, and specific, and recoveries from biological samples were quantitative. Metronidazole and tinidazole were given as rapid intravenous infusions to four healthy human volunteers. The biological half-lives of these two compounds were 5.4 and 11.1 h, respectively. The hydroxy metabolite of metronidazole appeared quickly in serum and was eliminated at a slow rate. The acetic acid metabolite of metronidazole was detected in serum at very low levels and only for a limited time. No metabolic products of tinidazole were found in serum samples. In urine, 43.7% of the administered dose of metronidazole was recovered over a period of 24 h (24.1% of the dose as the hydroxy metabolite, 12.0% as the acetic acid metabolite, and 7.6% as unchanged drug). Only 18.4% of the infused dose of tinidazole was eliminated in urine over a period of 72 h, and no metabolic products were detected. PMID:7294765

  18. Molecular analysis of the relationship between specific vaginal bacteria and bacterial vaginosis metronidazole therapy failure.

    PubMed

    Wang, B; Xiao, B B; Shang, C G; Wang, K; Na, R S; Nu, X X; Liao, Q

    2014-10-01

    Bacterial vaginosis frequently persists, even after treatment. The role of some strains of bacteria associated with bacterial vaginosis treatment failure remains poorly defined. The aim of our study was to define the risk of bacterial vaginosis treatment failure, including pre-treatment detection of specific vaginal bacteria. Bacterial vaginosis is present when the Nugent score is ≥7 and the modified Amsel criteria is positive. Women with bacterial vaginosis were treated with intravaginal metronidazole gel nightly for 5 nights. The 454 pyrosequencing method was used to detect bacteria in vaginal fluid. By univariate analysis, a history of bacterial vaginosis, intrauterine device use and the presence of Facklamia, Corynebacterium and Veillonella were significantly associated with bacterial vaginosis treatment failure. Lactobacillus crispatus, Lactobacillus pentosus and Megasphaera were significantly associated with curing bacterial vaginosis. After logistic regression analysis and detection of these bacteria for test-of-cure, we found that women who had a history of bacterial vaginosis had a higher incidence of bacterial vaginosis treatment failure, whereas women with L. crispatus had a lower incidence of treatment failure. Post-treatment sexual activity was not associated with the treatment effect. Our data suggested that treatment failure may be not caused by drug resistance. Rather, it has a closer relationship with the failed restoration of lactobacilli.

  19. Investigation of PAA/PVDF-NZVI hybrids for metronidazole removal: synthesis, characterization, and reactivity characteristics.

    PubMed

    Yang, Jiacheng; Wang, Xiangyu; Zhu, Minping; Liu, Huiling; Ma, Jun

    2014-01-15

    For the first time, the removal process of metronidazole (MNZ) from aqueous solutions over nano zerovalent iron (NZVI) encapsulated within poly(acrylic acid) (PAA)/poly(vinylidene fluoride) (PVDF) membranes was reported. The resultant composite (PPN) demonstrated high reactivity, excellent stability and reusability over the reaction course. Such excellent performance might be attributed to the presence of the charged carboxyl groups in PVDF membrane support, which could enhance NZVI dispersion and improve its longevity. Results showed that a lower initial concentration and higher reaction temperature facilitated the removal of MNZ by PPN, and that the acidic and neutral conditions generally exhibited more favorable effect on MNZ removal than the alkaline ones. Kinetics of the MNZ removal by PPN was found to follow a two-parameter pseudo-first-order decay model well, and the activation energy of the MNZ degradation by PPN was determined to be 30.49kJ/mol. The presence of chloride ions slightly enhanced the reactivity of PPN with MNZ, whereas sulfate ions inhibited its reactivity. In addition, MNZ degradation pathways by PPN were proposed based on the identified intermediates. This study suggests that PPN composite possessing excellent performance may be a promising functional material to pretreat antibiotic wastewaters. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Photocatalytic degradation of Metronidazole with illuminated TiO2 nanoparticles.

    PubMed

    Farzadkia, Mahdi; Bazrafshan, Edris; Esrafili, Ali; Yang, Jae-Kyu; Shirzad-Siboni, Mehdi

    2015-01-01

    Metronidazole (MNZ) is a brand of nitroimidazole antibiotic, which is generally used in clinical applications and extensively used for the treatment of infectious diseases caused by anaerobic bacteria and protozoans. The aim of this investigation was to degrade MNZ with illuminated TiO2 nanoparticles at different catalyst dosage, contact time, pH, initial MNZ concentration and lamp intensity. Maximum removal of MNZ was observed at near neutral pH. Removal efficiency was decreased by increasing dosage and initial MNZ concentration. The reaction rate constant (k obs ) was decreased from 0.0513 to 0.0072 min(-1) and the value of electrical energy per order (EEo) was increased from 93.57 to 666.67 (kWh/m(3)) with increasing initial MNZ concentration from 40 to 120 mg/L, respectively. The biodegradability estimated from the BOD5/COD ratio was increased from 0 to 0.098. The photocatalyst demonstrated proper photocatalytic activity even after five successive cycles. Finally, UV/TiO2 is identified as a promising technique for the removal of antibiotic with high efficiency in a relatively short reaction time.

  1. Depletion of metronidazole in brook trout (Salvelinus fontinalis).

    PubMed

    Watson, Lynn; MacNeil, James D; Potter, Ross; Hellou, Jocelyne

    2015-01-01

    Metronidazole (MNZ), which is effective in the treatment of intestinal infections in fish, is also a suspected carcinogen and has been banned in numerous jurisdictions for use in any food-producing animal, including fish. Few reports have been published on the depletion of MNZ in fish. A depletion study was therefore undertaken using MNZ in feed provided to trout under controlled conditions. The water was maintained at 17.5 ± 0.9°C throughout the medication and depletion periods in the study. Following a 20-day acclimatisation period in the holding tanks, the trout (approximately 150-200 g bodyweight at the start of the study) were subjected to two separate medication and withdrawal periods: (A) 5 day medication/5 day withdrawal and (B) 5 day medication/16 day withdrawal. This simulated a potential multiple dosing in an aquaculture setting. In both medication periods, the trout were dosed with medicated feed containing 3 g MNZ kg(-1) fish. Fish were sacrificed in accordance with accepted animal care protocols and tissue samples were analysed by UPLC-MS/MS. Analyte concentrations in trout muscle ranged from a high of 27,000 ± 10,000 ng g(-1) for MNZ and 830 ± 570 ng g(-1) for MNZ-OH on day 1 of withdrawal period A to a low of 1.8 ± 2.3 ng g(-1) for MNZ and < 0.4 ng g(-1) for MNZ-OH on day 16 of withdrawal period B. The results demonstrate that when using the UPLC-MS/MS method, residues of MNZ may be detected in fish treated with MNZ after 16 days of withdrawal.

  2. BASIC study: is intravaginal boric acid non-inferior to metronidazole in symptomatic bacterial vaginosis? Study protocol for a randomized controlled trial.

    PubMed

    Zeron Mullins, Melinda; Trouton, Konia M

    2015-07-26

    Bacterial vaginosis is associated with increased transmission of sexually transmitted infections, preterm labor, post-surgical infections, and endometritis. Current treatment for symptomatic bacterial vaginosis includes antibiotics, such as metronidazole, which are 70-80 % effective at one month after treatment and result in high recurrence rates and secondary candida infections. Intravaginal boric acid has been used for over a hundred years to treat vaginal infections, such as bacterial vaginosis. Boric acid is inexpensive, accessible, and has shown to be an effective treatment for other infections, such as vaginal candidiasis. To date, there has been no clinical trial evaluation of boric acid effectiveness to treat bacterial vaginosis. The BASIC (Boric Acid, Alternate Solution for Intravaginal Colonization) trial is a randomized, double-blinded, multicenter study. The study will enroll a minimum of 240 women of 16-50 years of age who are symptomatic with bacterial vaginosis. Eligible participants will have Amsel and Nugent scores confirming bacterial vaginosis. Women who are pregnant or menopausal or have other active co-infections will be excluded. Consenting participants who meet exclusion and inclusion criteria will be randomly assigned to one of three treatment groups: boric acid, metronidazole, or an inert placebo. Self-administration of treatment intravaginally for 10 days will be followed by clinical assessment at 7 and 30 days (days 17 and 40, respectively) after the end of the treatment phase. Primary outcome is a non-inferiority, per-protocol comparison of the effectiveness of boric acid with that of metronidazole at day 17, as measured by the Nugent score in 16-50 year olds. Secondary outcomes include: non-inferiority, intention-to-treat comparison of effectiveness of boric acid with that of metronidazole at day 17, analysis for both per-protocol and intention-to-treat at day 40, and safety considerations, including adverse effects requiring patient

  3. Prevalence of Helicobacter pylori resistance to metronidazole, clarithromycin, amoxycillin, tetracycline and trovafloxacin in The Netherlands.

    PubMed

    Debets-Ossenkopp, Y J; Herscheid, A J; Pot, R G; Kuipers, E J; Kusters, J G; Vandenbroucke-Grauls, C M

    1999-04-01

    Successful treatment of Helicobacter pylori infection is becoming compromised by emerging resistance. We report the prevalence rates of H. pylori resistance to metronidazole, clarithromycin, amoxycillin, tetracycline and trovafloxacin in The Netherlands. A total of 231 H. pylori clinical isolates were collected throughout the country over a period of 6 months during 1997-1998. The MICs of the above-mentioned antibiotics were determined in a single laboratory. The overall percentage of resistance for clarithromycin and metronidazole was 1.7% and 21.2%, respectively. None of the strains was resistant to amoxycillin or tetracycline. The primary resistance rate of trovafloxacin was as high as 4.7%. Since trovafloxacin has not yet been introduced on to the Dutch market, the resistance is probably induced by the use of other quinolones. Our data indicate that treatment outcome would benefit from susceptibility testing before starting therapy, especially when prescribing metronidazole.

  4. Lymphocyte proliferation kinetics and sister-chromatid exchanges in individuals treated with metronidazole.

    PubMed

    Elizondo, G; Montero, R; Herrera, J E; Hong, E; Ostrosky-Wegman, P

    1994-03-01

    Metronidazole, an effective agent for the treatment of protozoan infections, is frequently used in developing countries. However, the employment of this drug has been questioned in view of its mutagenicity in bacteria and carcinogenicity in mice. A genotoxic study was carried out in which cellular proliferation kinetics and the frequency of sister-chromatid exchanges were determined in human peripheral blood lymphocytes from 12 individuals treated with therapeutic doses of metronidazole. No effect was observed on mitotic index with the treatment, although a significant increase was found in three individuals after treatment. No increase of sister-chromatid exchanges was detected. The rate of lymphocyte proliferation kinetics showed an increase after the metronidazole treatment in all patients, indicating a possible immunostimulatory action.

  5. Coordination of metronidazole to Cu(II): Structural characterization of a mononuclear square-planar compound

    NASA Astrophysics Data System (ADS)

    Palmer, Joshua H.; Wu, Ja-Shin; Upmacis, Rita K.

    2015-07-01

    The reaction between metronidazole [1-(2-hydroxyethyl)-2-methyl-5-nitroimidazole, MET] and CuCl2ṡ2H2O in methanol solution has allowed isolation of blue crystals of composition Cu(MET)2Cl2ṡMeOH. These crystals have been shown by X-ray diffraction to consist of mononuclear square-planar trans-Cu(MET)2Cl2 molecules in which the metronidazole ligands are trans to each other, as are the Cl ligands. The structure of this compound is very different from other compounds that have been obtained from the reaction between CuCl2ṡ2H2O and metronidazole, namely [Cu(MET)2(μ-Cl)Cl]2 and [Cu(MET)2(μ-Cl)(OH2)]2[Cl]2, which are dimers featuring bridging chloride ligands.

  6. The use of metronidazole, tinidazole and dimetridazole in eliminating trichomonads from laboratory mice.

    PubMed

    Roach, P D; Wallis, P M; Olson, M E

    1988-10-01

    Metronidazole, tinidazole and dimetridazole were administered in the drinking water for 5 days to mice experimentally infected with Tritrichomonas muris and Tetratrichomonas microta. Mice were successfully infected with T. muris and T. microta recovered from infected gerbils. The trichomonas infection was successfully eliminated in mice given a 1% sucrose solution containing 2.5 mg/ml metronidazole or tinidazole. Mice receiving 1.0 mg/ml metronidazole, 1.0 mg/ml tinidazole and 1.2, 5.0 and 10.0 mg/ml dimetridazole failed to eliminate the trichomonas organism. A reduction in water intake was only noted with mice receiving 10 mg/ml dimetridazole. In mice receiving only 1% sucrose the infection was not eliminated.

  7. A simple reagent-free spectrophotometric assay for monitoring metronidazole therapy in aquarium water.

    PubMed

    Webb, D Harry; Marrero, Cynthia; Ellis, Helen; Merriwether, Lea; Dove, Alistair D M

    2013-09-01

    A reagent-free spectrophotometric assay was developed to measure the concentration of metronidazole (a 5-nitroimidazole) in both freshwater and seawater matrices. This assay is simple, repeatable, sensitive, and precise and is ideal for use when a rapid, selective test to determine metronidazole concentration in aqueous matrices is necessary. The assay was practically tested on a South American fishes display during treatment with metronidazole for an outbreak of the flagellated parasite Spironucleus in a mixed cichlid (family Cichlidae) and tetra (family Characidae) community. The assay clearly illustrated the course of treatment for the system during a real clinical application. The assay is not without limitations, as interferences can occur from other drugs in the matrix with similar absorbance spectra. Nonetheless, this type of assay illustrates the potential for use of native absorbance assays in aqueous matrices for this and other therapeutic compounds.

  8. Effects of metronidazole, ipronidazole, and dibromochloropropane on rabbit and human sperm motility and fertility.

    PubMed

    Foote, Robert H

    2002-01-01

    Treatment of protozoal pathogens in the reproductive system with chemical agents exposes flagellated sperm cells to potential toxicants. A widely used antiprotozoal agent is metronidazole. Its effect on rabbit and human sperm was compared with a more soluble 5-nitroazole compound, ipronidazole, and with a systemic environmental toxicant, dibromochloropropane (DBCP). The percentages of motile rabbit and human sperm incubated with the compounds, the velocity of sperm, migration of sperm in polyacrylamide gel, young born in rabbits, and penetration of hamster oocytes by treated human sperm were measured in seven experiments. Up to 10mg/ml metronidazole and 1mg/ml DBCP had little effect on most sperm characteristics. However, 10mg/ml metronidazole and 5mg/ml of ipronidazole increased attachment of human sperm to hamster oocytes, but oocyte penetration was unaffected. Rabbit sperm exposed to 5mg/ml ipronidazole were infertile. No oocytes were penetrated by DBCP-treated human sperm.

  9. Metronidazole Appears Not to Be a Human Teratogen: Review of Literature

    PubMed Central

    Struthers, Barbara J.

    1997-01-01

    Metronidazole is used to treat trichomoniasis, bacterial vaginosis, and other diseases. As is the case with many drugs, physicians often hesitate to use it during pregnancy, particularly in the first trimester. A review of the nearly four decades' worth of published literature on metronidazole use in pregnant women indicates that it is not teratogenic, regardless of the trimester in which it is used. On the other hand, a number of published studies indicate that bacterial vaginosis and trichomoniasis are associated with preterm birth and low birth weight. Treatment of these conditions with metronidazole during pregnancy may decrease the incidence of preterm birth and low birth weight, thus potentially decreasing the complications that can result from prematurity. PMID:18476180

  10. Novel vaccine potential of Rv3131, a DosR regulon-encoded putative nitroreductase, against hyper-virulent Mycobacterium tuberculosis strain K.

    PubMed

    Kwon, Kee Woong; Kim, Woo Sik; Kim, Hongmin; Han, Seung Jung; Hahn, Mi-Young; Lee, Jong Seok; Nam, Ki Taek; Cho, Sang-Nae; Shin, Sung Jae

    2017-03-08

    Accumulating evidence indicates that latency-associated Mycobacterium tuberculosis (Mtb)-specific antigens from the dormancy survival regulator regulon (DosR) may be promising novel vaccine target antigens for the development of an improved tuberculosis vaccine. After transcriptional profiling of DosR-related genes in the hyper-virulent Beijing Mtb strain K and the reference Mtb strain H37Rv, we selected Rv3131, a hypothetical nitroreductase, as a vaccine antigen and evaluated its vaccine efficacy against Mtb K. Mtb K exhibited stable and constitutive up-regulation of rv3131 relative to Mtb H37Rv under three different growth conditions (at least 2-fold induction) including exponential growth in normal culture conditions, hypoxia, and inside macrophages. Mice immunised with Rv3131 formulated in GLA-SE, a well-defined TLR4 adjuvant, displayed enhanced Rv3131-specific IFN-γ and serum IgG2c responses along with effector/memory T cell expansion and remarkable generation of Rv3131-specific multifunctional CD4(+) T cells co-producing TNF-α, IFN-γ and IL-2 in both spleen and lung. Following challenge with Mtb K, the Rv3131/GLA-SE-immunised group exhibited a significant reduction in bacterial number and less extensive lung inflammation accompanied by the obvious persistence of Rv3131-specific multifunctional CD4(+) T cells. These results suggest that Rv3131 could be an excellent candidate for potential use in a multi-antigenic Mtb subunit vaccine, especially against Mtb Beijing strains.

  11. Novel vaccine potential of Rv3131, a DosR regulon-encoded putative nitroreductase, against hyper-virulent Mycobacterium tuberculosis strain K

    PubMed Central

    Kwon, Kee Woong; Kim, Woo Sik; Kim, Hongmin; Han, Seung Jung; Hahn, Mi-Young; Lee, Jong Seok; Nam, Ki Taek; Cho, Sang-Nae; Shin, Sung Jae

    2017-01-01

    Accumulating evidence indicates that latency-associated Mycobacterium tuberculosis (Mtb)-specific antigens from the dormancy survival regulator regulon (DosR) may be promising novel vaccine target antigens for the development of an improved tuberculosis vaccine. After transcriptional profiling of DosR-related genes in the hyper-virulent Beijing Mtb strain K and the reference Mtb strain H37Rv, we selected Rv3131, a hypothetical nitroreductase, as a vaccine antigen and evaluated its vaccine efficacy against Mtb K. Mtb K exhibited stable and constitutive up-regulation of rv3131 relative to Mtb H37Rv under three different growth conditions (at least 2-fold induction) including exponential growth in normal culture conditions, hypoxia, and inside macrophages. Mice immunised with Rv3131 formulated in GLA-SE, a well-defined TLR4 adjuvant, displayed enhanced Rv3131-specific IFN-γ and serum IgG2c responses along with effector/memory T cell expansion and remarkable generation of Rv3131-specific multifunctional CD4+ T cells co-producing TNF-α, IFN-γ and IL-2 in both spleen and lung. Following challenge with Mtb K, the Rv3131/GLA-SE-immunised group exhibited a significant reduction in bacterial number and less extensive lung inflammation accompanied by the obvious persistence of Rv3131-specific multifunctional CD4+ T cells. These results suggest that Rv3131 could be an excellent candidate for potential use in a multi-antigenic Mtb subunit vaccine, especially against Mtb Beijing strains. PMID:28272457

  12. Low antibiotic resistance among anaerobic Gram-negative bacteria in periodontitis 5 years following metronidazole therapy.

    PubMed

    Dahlen, G; Preus, H R

    2017-02-01

    The objective of this study was to assess antibiotic susceptibility among predominant Gram-negative anaerobic bacteria isolated from periodontitis patients who 5 years prior had been subject to mechanical therapy with or without adjunctive metronidazole. One pooled sample was taken from the 5 deepest sites of each of 161 patients that completed the 5 year follow-up after therapy. The samples were analyzed by culture. A total number of 85 anaerobic strains were isolated from the predominant subgingival flora of 65/161 patient samples, identified, and tested for antibiotic susceptibility by MIC determination. E-tests against metronidazole, penicillin, amoxicillin, amoxicillin + clavulanic acid and clindamycin were employed. The 73/85 strains were Gram-negative rods (21 Porphyromonas spp., 22 Prevotella/Bacteroides spp., 23 Fusobacterium/Filifactor spp., 3 Campylobacter spp. and 4 Tannerella forsythia). These were all isolated from the treated patients irrespective of therapy procedures (+/-metronidazole) 5 years prior. Three strains (Bifidobacterium spp., Propionibacterium propionicum, Parvimonas micra) showed MIC values for metronidazole over the European Committee on Antimicrobial Susceptibility Testing break point of >4 μg/mL. All Porphyromonas and Tannerella strains were highly susceptible. Metronidazole resistant Gram-negative strains were not found, while a few showed resistance against beta-lactam antibiotics. In this population of 161 patients who had been subject to mechanical periodontal therapy with or without adjunct metronidazole 5 years prior, no cultivable antibiotic resistant anaerobes were found in the predominant subgingival microbiota. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Optimization of metronidazole sustained-release films using D-optimal design.

    PubMed

    Peerapattana, Jomjai; Ngamsupsiri, Teeraphat; Cheucharoenvasuchai, Nopadol; Saikaew, Charnnarong

    2015-04-30

    The aim of this study was to develop sustained-release metronidazole films for periodontal pockets using a computer-aided statistical approach. The studied independent variables were the amount of polycaprolactone, metronidazole, hydroxypropylmethyl cellulose and glyceryl monostearate. The response of interest was the cumulative percentage release of metronidazole at 1, 2, 3, 4 and 5 days. The films were prepared using a melt method. The physicochemical properties and release profiles of the films were investigated. Model validation was also performed. The produced films were thin white sheets with a smooth and glossy surface. Each sheet had an average weight of 9.31 ± 0.10mg. The metronidazole was uniformly dispersed in the film, and the percentage of drug loading was 100.12 ± 4.38%. The thickness of the film was 325 ± 5.27 μm. The puncture strength, % elongation and Young's modulus were 11.58 ± 0.51 N/mm(2), 33.51 ± 3.61%, and 0.347 ± 0.02 1N/mm(2), respectively. The actual drug release profiles of the optimal formulation films were close to the predicted responses. Metronidazole was slowly released from the matrices over a period of at least 5 days. The release mechanism of the films followed Fickian diffusion. This study demonstrates that appropriate D-optimal design and optimization techniques can be successfully used in the development of metronidazole sustained-release films. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Preparation and evaluation of topical microemulsion system containing metronidazole for remission in rosacea.

    PubMed

    Tirnaksiz, Figen; Kayiş, Ayşegül; Çelebi, Nevin; Adişen, Esra; Erel, Arzu

    2012-01-01

    The aim of this study was to prepare a topical water-in-oil type microemulsion containing metronidazole and to compare its effectiveness with a commercial gel product in the treatment of rosacea. A pseudo-ternary phase diagram (K(m)=2:1) was constructed using lecithin/butanol/isopropyl myristate/water. The microemulsion was chosen from the microemulsion region in the phase diagram. The formulation was a water-in-oil type microemulsion (droplet size: 11.6 nm, viscosity: 457.3 mPa·s, conductivity: 1.5 µs/cm, turbidity: 6.89 NTU) and the addition of the metronidazole did not alter the properties of the system. The release experiment showed that the release rate of metronidazole from the commercial gel product was higher than that of the microemulsion. Stability experiments showed that the metronidazole microemulsion remained stable for at least 6 months; none of the characteristic properties of the microemulsion had changed, the system retained its clarity and there was no sign that crystallization of metronidazole has occurred. Microemulsion was compared to a gel product in a randomized, double-blind, baseline-controlled, split-face clinical trial for the treatment of patients. After the 6-week treatment period there was a statistically significant difference in reduction of the main symptoms of rosacea. Of the patients treated with the microemulsion, 17% experienced complete relief from inflammatory lesions, and 50% from erythema. The microemulsion resulted in complete relief in 38% of the patients with telangiectasia while the commercial product did not provide any relief of telangiectasia symptoms. In conclusion, the microemulsion containing metronidazole was found to be more effective in reducing the symptoms of rosacea compared to the commercial gel product.

  15. Diazepam as a treatment for metronidazole toxicosis in dogs: a retrospective study of 21 cases.

    PubMed

    Evans, Jason; Levesque, Donald; Knowles, Kim; Longshore, Randy; Plummer, Scott

    2003-01-01

    The currently recommended treatment for metronidazole toxicosis is drug discontinuation and supportive therapy. Reported recovery times are 1-2 weeks. The records of 21 dogs with metronidazole toxicosis were retrospectively analyzed to determine whether diazepam improved recovery. The dosage and duration of metronidazole therapy and the response and recovery times of 13 dogs treated with diazepam were compared to those of 8 dogs receiving only supportive care. Response time was defined as the time to resolution of the debilitating clinical signs. Recovery time was the time to resolution of all residual clinical signs. The average dosage and duration of metronidazole administration for the diazepam-treated and untreated groups were 60.3 mg/kg/d for 44.9 days and 65.1 mg/kg/d for 37.25 days. The protocol for diazepam administration consisted of an initial i.v. bolus and then diazepam PO q8h for 3 days. The average dosage of both the i.v. and PO diazepam was 0.43 mg/kg. The average response time for the diazepam-treated dogs was 13.4 hours compared to 4.25 days for the untreated group. Recovery time also was markedly shorter for the diazepam-treated dogs (38.8 hours) compared to the untreated group (11 days). Results of this study showed that dogs with metronidazole toxicosis recover faster when treated with diazepam. Although the mechanism of metronidazole toxicosis or how diazepam exerts its favorable effect is not known, it is likely related to modulation of the gamma-aminobutyric acid (GABA) receptor within the cerebellar and vestibular systems.

  16. The effect of 3-(biphenyl-4-yl)-3-hydoxyquinuclidine (BPQ-OH) and metronidazole on Trichomonas vaginalis: a comparative study.

    PubMed

    Rocha, Débora Afonso Silva; de Andrade Rosa, Ivone; Urbina, Julio A; de Souza, Wanderley; Benchimol, Marlene

    2014-06-01

    Trichomonas vaginalis causes trichomoniasis in humans, a sexually transmitted disease commonly treated with metronidazole (MTZ), a drug that presents some toxicity, causing undesirable side effects. In addition, an increase in metronidazole-resistant parasites has been reported. Thus, the development of alternative treatment is recommended. To date, the search for antiparasitic drugs has been based on different approaches: identification of active natural products, identification of parasite targets, and the use of available compounds active against other pathogenic microorganisms. Here, we analyzed the in vitro antiproliferative and ultrastructural effects on T. vaginalis of BPQ-OH, a hydroxiquinuclidine derivative that inhibits squalene synthase and is active against several protozoa and fungi. We also compared the effects of BPQ-OH on T. vaginalis and mammalian cells with those of MTZ. We found that BPQ-OH inhibits in vitro proliferation of T. vaginalis, with an IC50 of 46 μM after 24 h. Although this IC50 is 16 times higher than that of MTZ (1.8 μM), BPQ-OH is less toxic for human cell lines than MTZ, with LC50 values of 2,300 and 70 μM, and selective indexes of 50 and 39, respectively. Ultrastructural analyses demonstrated that BPQ-OH induced alterations in T. vaginalis, such as rounded and wrinkled cells, membrane blebbing and intense vacuolization, leading to cell death, whereas MTZ also caused significant changes, including a decrease in hydrogenosomes size and endoflagellar forms. Our observations identify BPQ-OH as a promising leading compound for the development of novel anti-T. vaginalis drugs and highlight the need for further testing this molecule using experimentally infected animals.

  17. Bismuth, lansoprazole, amoxicillin and metronidazole or clarithromycin as first-line Helicobacter pylori therapy.

    PubMed

    Zhang, Wei; Chen, Qi; Liang, Xiao; Liu, Wenzhong; Xiao, Shudong; Graham, David Y; Lu, Hong

    2015-11-01

    To evaluate the efficacy and tolerability of replacing tetracycline with amoxicillin in bismuth quadruple therapy. Subjects who were infected with Helicobacter pylori and naïve to treatment were randomly (1:1) assigned to receive a 14-day modified bismuth quadruple therapy: lansoprazole 30 mg, amoxicillin 1 g, bismuth potassium citrate 220 mg (elemental bismuth), twice a day with metronidazole 400 mg four times a day (metronidazole group) or clarithromycin 500 mg twice a day (clarithromycin group). Six weeks after treatment, H. pylori eradication was assessed by 13C-urea breath test. Antimicrobial susceptibility was assessed by the twofold agar dilution method. This was a non-inferiority trial. Two hundred and fifteen subjects were randomised. Metronidazole and clarithromycin containing regimens achieved high cure rates: 94 of 97 (96.9%, 95% CI 93.5% to 100%) and 93 of 98 (94.9%, 95% CI 90.5% to 99.3%) by per-protocol and 88.9% (95% CI 83.0% to 94.8%) and 88.8% (95% CI 82.8% to 94.8%) by intention-to-treat, respectively. Amoxicillin, metronidazole and clarithromycin resistance rates were 1.5%, 45.5% and 26.5%, respectively. Only clarithromycin resistance reduced treatment success (e.g., susceptible 98.6%, resistant 76.9%, p=0.001). Adverse events were more common in the metronidazole group. These results suggest that amoxicillin can substitute for tetracycline in modified 14 day bismuth quadruple therapy as first-line treatment and still overcome metronidazole resistance in areas with high prevalence of metronidazole and clarithromycin resistance. Using clarithromycin instead of metronidazole was only effective in the presence of susceptible strains. NCT02175901. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  18. Symmetrical drug-related intertriginous and flexural exanthema (SDRIFE) induced by oral metronidazole.

    PubMed

    Şikar Aktürk, Aysun; Bayramgürler, Dilek; Salman, Selma; Yıldız, Kürşat Demir; Odyakmaz Demirsoy, Evren

    2014-12-01

    Baboon syndrome is a special form of systemic contact dermatitis to systemic or local administration of contact allergens. Baboon syndrome without known previous cutaneous sensitisation was also described as drug-related baboon syndrome or symmetrical drug-related intertriginous and flexural exanthema (SDRIFE). The major drugs causing SDRIFE was beta-lactam antibiotic such as amoxicillin and ampicillin. We report a case of 16-year-old woman who developed pruritic eruptions after oral metronidazole treatment for diarrhea. She was diagnosed SDRIFE according to her clinical and histopathological findings. To our knowledge, our patient is the first case who developed SDRIFE due to metronidazole in the literature.

  19. Development of serratiopeptidase and metronidazole based alginate microspheres for wound healing.

    PubMed

    Rath, G; Johal, E S; Goyal, Amit K

    2011-02-01

    The objective of this study was to establish an effective therapy system for wound management. The present work describes preparation of metronidazole/serratiopeptidase loaded alginate microspheres by emulsification method. In vitro characterizations like particle size analysis, % yield, % encapsulation, and in vitro release were carried out. Wound healing assessment was determined by physical, histological, and biochemical methods. Wound healing performance of experimental formulations was compared with marketed product in rabbits. Result obtained for alginate microspheres showed good loading efficiency with spherical in shape. Experimentation suggests wound healing is improved by using serratiopeptidase and metronidazole in full thickness wounds in rabbits.

  20. Propionylcarnitine excretion is not affected by metronidazole administration to patients with disorders of propionate metabolism.

    PubMed

    Burns, S P; Iles, R A; Saudubray, J M; Chalmers, R A

    1996-01-01

    Propionylcarnitine (PC) excretion has been measured during a clinical trial of metronidazole therapy in two patients with propionic acidaemia and two patients with methylmalonic aciduria. All patients were in good metabolic control and were receiving L-carnitine. While total propionate excretion was reduced by up to 40% in all four patients during metronidazole therapy, the excretion of propionylcarnitine remained largely unchanged. PC comprised up to 80% of total propionate excretion in patients with propionic acidaemia. These results suggest an extra-hepatic source and/or differing compartmentation for PC formation from those for the production of other metabolites of propionyl-CoA.

  1. Enhanced bacterial efflux system is the first step to the development of metronidazole resistance in Helicobacter pylori.

    PubMed

    Tsugawa, Hitoshi; Suzuki, Hidekazu; Muraoka, Hiroe; Ikeda, Fumiaki; Hirata, Kenro; Matsuzaki, Juntaro; Saito, Yoshimasa; Hibi, Toshifumi

    2011-01-14

    Although metronidazole (Mtz) is an important component of Helicobacter pylori eradication regimens, it has been pointed out that the increasing use of Mtz may result in increase in the incidence of Mtz-resistant strains. The present study was designed to examine the initial mechanism of resistance acquisition of H. pylori to Mtz. After 10 Mtz-susceptible strains were cultured on plates containing sub-inhibitory concentrations of Mtz, the MIC of Mtz for 9 of the 10 strains increased to levels of the Mtz-resistant strains. In the Mtz-resistance-induced strains, the expression of the TolC efflux pump (hefA) was significantly increased under Mtz exposure, without the reduction of the Mtz-reductive activity. Our finding suggests that overexpression of hefA may be the initial step in the acquisition of Mtz resistance in H. pylori. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Population pharmacokinetic modeling and Monte Carlo simulation of varying doses of intravenous metronidazole.

    PubMed

    Sprandel, Kelly A; Drusano, George L; Hecht, David W; Rotschafer, John C; Danziger, Larry H; Rodvold, Keith A

    2006-08-01

    Population pharmacokinetic modeling and Monte Carlo simulation (MCS) are approaches used to determine probability of target attainment (PTA) of antimicrobial therapy. The objectives of this study were 1) to determine a population pharmacokinetic model (PPM) using metronidazole and hydroxy-metronidazole concentrations from healthy subjects and critically ill patients, and 2) to determine the probability of attaining the pharmacodynamic target area under the plasma concentration (AUC)/MIC ratio >or=70 against 218 clinical isolates of Bacteroides fragilis using MCS. Eighteen healthy subjects were randomized to 3 dosages of intravenous metronidazole (500 mg every 8 h, 1000 mg day(-1), 1500 mg day(-1)) in an open-label 3-way crossover fashion. Serial blood samples were collected over 25.5 h on the 3rd day of each study period. An additional of 8 critically ill patients received intravenous metronidazole 500 mg every 8 h. Serial blood samples were collected over 8 h after the 2nd day of dosing. Plasma metronidazole and hydroxy-metronidazole concentrations were analyzed using a high-performance liquid chromatographic assay. The 834 plasma concentrations from 62 data sets were simultaneously modeled with Non-Parametric Adaptive Grid population modeling program. A 4-compartment model with a metabolite and zero-order infusion into the central compartment was used. The mean parameter vector and covariance matrix from PPM were inserted into the simulation module of ADAPT II. A 10,000-subject MCS was performed to determine the probability of PTA for a total drug AUC to MIC ratio >or=70 against 218 isolates of B. fragilis (MIC range, 0.125-2.0 mg L(-1)). Mean parameter values were CL(non-OH), 3.08 L h(-1); Vc, 35.4 L; K(OH), 0.04 h(-1); CL(OH), 2.78 L h(-1); and V(OH), 9.66 L. The regression values of the observed versus predicted concentrations (r2) of metronidazole and hydroxy-metronidazole were 0.972 and 0.980, respectively. The PTA for metronidazole 1500 mg day(-1) or 500 mg

  3. Effects of metronidazole combined probiotics over metronidazole alone for the treatment of bacterial vaginosis: a meta-analysis of randomized clinical trials.

    PubMed

    Tan, Hongying; Fu, Yunque; Yang, Chunlin; Ma, Jianting

    2017-06-01

    To evaluate the curative effect of metronidazole combined probiotics over metronidazole alone in the treatment of BV. We are searching randomized controlled trials on major online databases including PubMed, Science Direct, and Cochrane Database between 1990 and 2015. The primary outcome measure was the cure rate of BV. Cochran's Chi-square test (Q test) was used to test for heterogeneity among trials, and the I (2) index. We used mixed-effects modeling for parameters of the summary hazard ratios (HRs), odds ratios (ORs), and their 95% confidence intervals (CIs). Analysis suggests the cure rate of BV [RR = 1.12, 95% CI (0.94-1.32), p = 0.20], and the I (2) index was 83%. The value of I (2) index decreased to 16% after removing the study of Anukam et al., and Amsel 1.04 (95% CI 0.96-1.13) (p = 0.35), Nugent 1.02 (95% CI 0.94-1.11), short-term 1.01 (95% CI 0.93-1.10) (p = 0.79), long-term 1.06 (95% CI 0.98-1.14) (p = 0.13), Europe 1.06 (95% CI 0.95-1.19) (p = 0.32), Non-Europe 0.99 (95% CI 0.94-1.05) (p = 0.83). When the two same groups data were combined, respectively, the RRs for all studies were the same as 1.03 (95% CI 0.96-1.09) (p = 0.42) showing that there is not statistically significant in relevant stratums. The result has showed an overall little significance for the efficacy of metronidazole combined probiotics over metronidazole alone for the treatment of BV. We need more further studies to provide enough evidence to confirm the benefits of probiotics in the treatment of BV.

  4. Impaired Parasite Attachment as Fitness Cost of Metronidazole Resistance in Giardia lamblia▿

    PubMed Central

    Tejman-Yarden, Noa; Millman, Maya; Lauwaet, Tineke; Davids, Barbara J.; Gillin, Frances D.; Dunn, Linda; Upcroft, Jacqueline A.; Miyamoto, Yukiko; Eckmann, Lars

    2011-01-01

    Infections with the diarrheagenic protozoan pathogen Giardia lamblia are most commonly treated with metronidazole (Mz). Treatment failures with Mz occur in 10 to 20% of cases and Mz resistance develops in the laboratory, yet clinically, Mz-resistant (Mzr) G. lamblia has rarely been isolated from patients. To understand why clinical Mzr isolates are rare, we questioned whether Mz resistance entails fitness costs to the parasite. Our studies employed several newly generated and established isogenic Mzr cell lines with stable, high-level resistance to Mz and significant cross-resistance to tinidazole, nitazoxanide, and furazolidone. Oral infection of suckling mice revealed that three of five Mzr cell lines could not establish infection, while two Mzr cell lines infected pups, albeit with reduced efficiencies. Failure to colonize resulted from a diminished capacity of the parasite to attach to the intestinal mucosa in vivo and to epithelial cells and plastic surfaces in vitro. The attachment defect was related to impaired glucose metabolism, since the noninfectious Mzr lines consumed less glucose, and glucose promoted ATP-independent parasite attachment in the parental lines. Thus, resistance of Giardia to Mz is accompanied by a glucose metabolism-related attachment defect that can interfere with colonization of the host. Because glucose-metabolizing pathways are important for activation of the prodrug Mz, it follows that a fitness trade-off exists between diminished Mz activation and reduced infectivity, which may explain the observed paucity of clinical Mzr isolates of Giardia. However, the data also caution that some forms of Mz resistance do not markedly interfere with in vivo infectivity. PMID:21825286

  5. Impaired parasite attachment as fitness cost of metronidazole resistance in Giardia lamblia.

    PubMed

    Tejman-Yarden, Noa; Millman, Maya; Lauwaet, Tineke; Davids, Barbara J; Gillin, Frances D; Dunn, Linda; Upcroft, Jacqueline A; Miyamoto, Yukiko; Eckmann, Lars

    2011-10-01

    Infections with the diarrheagenic protozoan pathogen Giardia lamblia are most commonly treated with metronidazole (Mz). Treatment failures with Mz occur in 10 to 20% of cases and Mz resistance develops in the laboratory, yet clinically, Mz-resistant (Mz(r)) G. lamblia has rarely been isolated from patients. To understand why clinical Mz(r) isolates are rare, we questioned whether Mz resistance entails fitness costs to the parasite. Our studies employed several newly generated and established isogenic Mz(r) cell lines with stable, high-level resistance to Mz and significant cross-resistance to tinidazole, nitazoxanide, and furazolidone. Oral infection of suckling mice revealed that three of five Mz(r) cell lines could not establish infection, while two Mz(r) cell lines infected pups, albeit with reduced efficiencies. Failure to colonize resulted from a diminished capacity of the parasite to attach to the intestinal mucosa in vivo and to epithelial cells and plastic surfaces in vitro. The attachment defect was related to impaired glucose metabolism, since the noninfectious Mz(r) lines consumed less glucose, and glucose promoted ATP-independent parasite attachment in the parental lines. Thus, resistance of Giardia to Mz is accompanied by a glucose metabolism-related attachment defect that can interfere with colonization of the host. Because glucose-metabolizing pathways are important for activation of the prodrug Mz, it follows that a fitness trade-off exists between diminished Mz activation and reduced infectivity, which may explain the observed paucity of clinical Mz(r) isolates of Giardia. However, the data also caution that some forms of Mz resistance do not markedly interfere with in vivo infectivity.

  6. Investigating the dissolution profiles of amoxicillin, metronidazole, and zidovudine formulations used in Trinidad and Tobago, West Indies.

    PubMed

    Stuart, Arlene Villarroel; Zuo, Jieyu; Löbenberg, Raimar

    2014-10-01

    Trinidad and Tobago is a twin-island Republic in the Caribbean and like many developing countries, it has included generic drugs on the national drug formulary to decrease the financial burden of pharmaceutical medications. However, to ensure that medications received by patients are beneficial, generic drugs need to be interchangeable with the innovator which has demonstrated safety, efficacy, and quality. The objective of the study was to compare the dissolution profiles and weight variations for different formulations of amoxicillin, metronidazole, and zidovudine that are on the national drug formulary and marketed in Trinidad and Tobago. All the products investigated are categorized as class 1 drugs according to the Biopharmaceutics Classification System (BCS) and the dissolution profiles were assessed according to the World Health Organization (WHO) criteria for interchangeability between products. The similarity factor, f 2, was used to determine sameness between the products. No generic formulation was found to be similar to Amoxil® 500-mg capsules. The two generic products for metronidazole 200-mg tablets demonstrated more than 85% drug release within 15 min in all three of the buffers; however, their 400-mg counterparts did not fulfill this requirement. The zidovudine 300-mg tablet complied with the requirements in buffer pH 4.5 and simulated gastric fluid (SGF) but not for simulated intestinal fluid (SIF). Some Class 1 pharmaceutical formulations may possess the same active ingredient and amount of drug but may show significant differences to in vitro equivalence requirements. Nevertheless, the dissolution process is suitable to detect these variations.

  7. Risk of Clostridium difficile infection in intensive care unit patients with sepsis exposed to metronidazole.

    PubMed

    Sabbah, Mohamad A; Schorr, Christa; Czosnowski, Quinn A; Hunter, Krystal; Torjman, Marc C; Fraimow, Henry S; Zanotti, Sergio; Tsigrelis, Constantine

    2015-04-01

    Antimicrobial agents used to treat Clostridium difficile infection (CDI), such as metronidazole and vancomycin, have been used during antibiotic treatment of other infections to try to prevent the development of CDI. We evaluated the hypothesis that intensive care unit (ICU) patients who receive metronidazole as part of an antibiotic treatment regimen for sepsis have a lower risk of subsequently developing CDI. This was a nested case-control study in a cohort of ICU patients who received antibiotic therapy for sepsis. A total of 10 012 patients aged ≥ 18 years were admitted to the Cooper University Hospital medical/surgical ICU from 1/1/2003 to 12/31/2008. After applying inclusion criteria including having received antibiotic therapy for sepsis and subsequently having developed CDI, 67 cases were identified. The cases were matched for age, gender, date of ICU admission, and hospital length of stay to 67 controls that also received antibiotic therapy for sepsis but did not subsequently develop CDI. In the multivariate analysis, there was no association between metronidazole exposure and the risk of CDI (odds ratio (OR) = 0.57; p = 0.23). The only significant associations on multivariate analysis were antifungal therapy (OR = 0.30; p = 0.02) and aminoglycoside and/or colistin therapy (OR = 0.17; p = 0.02). No association was found between metronidazole use and subsequent CDI in ICU patients who received antibiotic therapy for sepsis.

  8. Effects of oral administration of metronidazole and doxycycline on olfactory capabilities of explosives detection dogs.

    PubMed

    Jenkins, Eileen K; Lee-Fowler, Tekla M; Angle, T Craig; Behrend, Ellen N; Moore, George E

    2016-08-01

    OBJECTIVE To determine effects of oral administration of metronidazole or doxycycline on olfactory function in explosives detection (ED) dogs. ANIMALS 18 ED dogs. PROCEDURES Metronidazole was administered (25 mg/kg, PO, q 12 h for 10 days); the day prior to drug administration was designated day 0. Odor detection threshold was measured with a standard scent wheel and 3 explosives (ammonium nitrate, trinitrotoluene, and smokeless powder; weight, 1 to 500 mg) on days 0, 5, and 10. Lowest repeatable weight detected was recorded as the detection threshold. There was a 10-day washout period, and doxycycline was administered (5 mg/kg, PO, q 12 h for 10 days) and the testing protocol repeated. Degradation changes in the detection threshold for dogs were assessed. RESULTS Metronidazole administration resulted in degradation of the detection threshold for 2 of 3 explosives (ammonium nitrate and trinitrotoluene). Nine of 18 dogs had a degradation of performance in response to 1 or more explosives (5 dogs had degradation on day 5 or 10 and 4 dogs had degradation on both days 5 and 10). There was no significant degradation during doxycycline administration. CONCLUSIONS AND CLINICAL RELEVANCE Degradation in the ability to detect odors of explosives during metronidazole administration at 25 mg/kg, PO, every 12 hours, indicated a potential risk for use of this drug in ED dogs. Additional studies will be needed to determine whether lower doses would have the same effect. Doxycycline administered at the tested dose appeared to be safe for use in ED dogs.

  9. Cervicovaginal bacterial count and failure of metronidazole therapy for bacterial vaginosis.

    PubMed

    Luchiari, Heloise R; Ferreira, Carolina S T; Golim, Márjorie A; Silva, Márcia G; Marconi, Camila

    2016-03-01

    To evaluate whether total bacterial count in cervicovaginal fluid is associated with failure of metronidazole therapy for bacterial vaginosis. In a cross-sectional study, women attending a primary health center in Botucatu, São Paulo, Brazil, for routine cervical screening between September 2012 and October 2013 were enrolled. Women who tested positive for bacterial vaginosis (Nugent classification) were offered oral metronidazole. Women who completed metronidazole treatment and an equal number of control women with normal vaginal flora at initial screening were included in analyses of total bacterial count, assessed by flow cytometry of cervicovaginal fluid samples. Of 287 women who enrolled, 49 were excluded because they tested positive for trichomoniasis, chlamydial endocervicitis, gonorrhea, or candidiasis. Among the remaining 238, 85 (35.7%) had bacterial vaginosis. Among 36 women evaluated at follow-up, 23 (63.9%) had successfully restored lactobacilli-dominant flora, 12 (33.3%) had persistent bacterial vaginosis, and 1 (2.8%) had vaginal candidiasis (excluded from flow cytometry). Total bacterial count did not differ between 35 women with bacterial vaginosis and 35 with normal vaginal flora (P=0.62). Total bacterial count did not differ at enrollment between women who went on to have persistent bacterial vaginosis and those who had successful treatment (P=0.78). Failure of oral metronidazole therapy for bacterial vaginosis was not associated with total bacterial count in cervicovaginal fluid. Copyright © 2015 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  10. Molecular and Proteomic Analysis of Levofloxacin and Metronidazole Resistant Helicobacter pylori

    PubMed Central

    Hanafi, Aimi; Lee, Woon Ching; Loke, Mun Fai; Teh, Xinsheng; Shaari, Ain; Dinarvand, Mojdeh; Lehours, Philippe; Mégraud, Francis; Leow, Alex Hwong Ruey; Vadivelu, Jamuna; Goh, Khean Lee

    2016-01-01

    Antibiotic resistance in bacteria incurs fitness cost, but compensatory mechanisms may ameliorate the cost and sustain the resistance even under antibiotics-free conditions. The aim of this study was to determine compensatory mechanisms of antibiotic resistance in H. pylori. Five strains of levofloxacin-sensitive H. pylori were induced in vitro to develop resistance. In addition, four pairs of metronidazole-sensitive and -resistant H. pylori strains were isolated from patients carrying dual H. pylori populations that consist of both sensitive and resistant phenotypes. Growth rate, virulence and biofilm-forming ability of the sensitive and resistant strains were compared to determine effects of compensatory response. Proteome profiles of paired sensitive and resistant strains were analyzed by liquid chromatography/mass spectrophotometry (LC/MS). Although there were no significant differences in growth rate between sensitive and resistant pairs, bacterial virulence (in terms of abilities to induce apoptosis and form biofilm) differs from pair to pair. These findings demonstrate the complex and strain-specific phenotypic changes in compensation for antibiotics resistance. Compensation for in vitro induced levofloxacin resistance involving mutations of gyrA and gyrB was functionally random. Furthermore, higher protein translation and non-functional protein degradation capabilities in naturally-occuring dual population metronidazole sensitive-resistant strains may be a possible alternative mechanism underlying resistance to metronidazole without mutations in rdxA and frxA. This may explain the lack of mutations in target genes in ~10% of metronidazole resistant strains. PMID:28018334

  11. Molecular and Proteomic Analysis of Levofloxacin and Metronidazole Resistant Helicobacter pylori.

    PubMed

    Hanafi, Aimi; Lee, Woon Ching; Loke, Mun Fai; Teh, Xinsheng; Shaari, Ain; Dinarvand, Mojdeh; Lehours, Philippe; Mégraud, Francis; Leow, Alex Hwong Ruey; Vadivelu, Jamuna; Goh, Khean Lee

    2016-01-01

    Antibiotic resistance in bacteria incurs fitness cost, but compensatory mechanisms may ameliorate the cost and sustain the resistance even under antibiotics-free conditions. The aim of this study was to determine compensatory mechanisms of antibiotic resistance in H. pylori. Five strains of levofloxacin-sensitive H. pylori were induced in vitro to develop resistance. In addition, four pairs of metronidazole-sensitive and -resistant H. pylori strains were isolated from patients carrying dual H. pylori populations that consist of both sensitive and resistant phenotypes. Growth rate, virulence and biofilm-forming ability of the sensitive and resistant strains were compared to determine effects of compensatory response. Proteome profiles of paired sensitive and resistant strains were analyzed by liquid chromatography/mass spectrophotometry (LC/MS). Although there were no significant differences in growth rate between sensitive and resistant pairs, bacterial virulence (in terms of abilities to induce apoptosis and form biofilm) differs from pair to pair. These findings demonstrate the complex and strain-specific phenotypic changes in compensation for antibiotics resistance. Compensation for in vitro induced levofloxacin resistance involving mutations of gyrA and gyrB was functionally random. Furthermore, higher protein translation and non-functional protein degradation capabilities in naturally-occuring dual population metronidazole sensitive-resistant strains may be a possible alternative mechanism underlying resistance to metronidazole without mutations in rdxA and frxA. This may explain the lack of mutations in target genes in ~10% of metronidazole resistant strains.

  12. Resistance pattern of Helicobacter pylori strains to clarithromycin, metronidazole, and amoxicillin in Isfahan, Iran.

    PubMed

    Khademi, Farzad; Faghri, Jamshid; Poursina, Farkhondeh; Esfahani, Bahram Nasr; Moghim, Sharareh; Fazeli, Hossein; Adibi, Peyman; Mirzaei, Nasrin; Akbari, Mojtaba; Safaei, Hajieh Ghasemian

    2013-12-01

    Helicobacter pylori (H. pylori) resistance to antibiotics has become a global problem and is an important factor in determining the outcome of treatment of infected patients. The purpose of this study was to determine the H. pylori resistance to clarithromycin, metronidazole, and amoxicillin in gastrointestinal disorders patients. In this study, a total of 260 gastric antrum biopsy specimens were collected from patients with gastrointestinal disorders who referred to Endoscopy Section of the Isfahan Hospitals. The E-test and Modified Disk Diffusion Method (MDDM) were used to verify the prevalence of antibiotic resistance in 78 H. pylori isolates to the clarithromycin, metronidazole, and amoxicillin. H. pylori resistance to clarithromycin, metronidazole, and amoxicillin were 15.3, 55.1, and 6.4%, respectively. In this study, we had one multidrug resistance (MDR) isolates from patient with gastritis and peptic ulcer disease. Information on antibiotic susceptibility profile plays an important role in empiric antibiotic treatment and management of refractive cases. According to the results obtained in this study, H. pylori resistance to clarithromycin and metronidazole was relatively high. MDR strains are emerging and will have an effect on the combination therapy.

  13. Resistance pattern of Helicobacter pylori strains to clarithromycin, metronidazole, and amoxicillin in Isfahan, Iran

    PubMed Central

    Khademi, Farzad; Faghri, Jamshid; Poursina, Farkhondeh; Esfahani, Bahram Nasr; Moghim, Sharareh; Fazeli, Hossein; Adibi, Peyman; Mirzaei, Nasrin; Akbari, Mojtaba; Safaei, Hajieh Ghasemian

    2013-01-01

    Background: Helicobacter pylori (H. pylori) resistance to antibiotics has become a global problem and is an important factor in determining the outcome of treatment of infected patients. The purpose of this study was to determine the H. pylori resistance to clarithromycin, metronidazole, and amoxicillin in gastrointestinal disorders patients. Materials and Methods: In this study, a total of 260 gastric antrum biopsy specimens were collected from patients with gastrointestinal disorders who referred to Endoscopy Section of the Isfahan Hospitals. The E-test and Modified Disk Diffusion Method (MDDM) were used to verify the prevalence of antibiotic resistance in 78 H. pylori isolates to the clarithromycin, metronidazole, and amoxicillin. Results: H. pylori resistance to clarithromycin, metronidazole, and amoxicillin were 15.3, 55.1, and 6.4%, respectively. In this study, we had one multidrug resistance (MDR) isolates from patient with gastritis and peptic ulcer disease. Conclusion: Information on antibiotic susceptibility profile plays an important role in empiric antibiotic treatment and management of refractive cases. According to the results obtained in this study, H. pylori resistance to clarithromycin and metronidazole was relatively high. MDR strains are emerging and will have an effect on the combination therapy. PMID:24523796

  14. Stability of metronidazole, tetracycline HCl and famotidine alone and in combination.

    PubMed

    Wu, Yunqi; Fassihi, Reza

    2005-02-16

    Metronidazole, tetracycline HCl and famotidine are commonly used for the treatment of Helicobacter pylori-associated peptic ulcer. In this paper, stabilities of these drugs and their combinations in solid and liquid states were studied as part of preformulation in the development of a combination drug delivery system. Solubility studies of metronidazole and tetracycline HCl were investigated, which indicated that both metronidazole and tetracycline HCl have high solubilities at and around pH 2.0. Metronidazole is relatively stable with little degradation in liquid phase. Tetracycline HCl in the dry state is stable when stored at room temperature regardless of exposure to light or humidity in the range of 20-65%. Enhanced temperature associated humidity effect was responsible for the instabilities of tetracycline HCl and famotidine to different extents. Elevated temperature accelerated the degradation of all the drugs in liquid phase but light exposure was not a factor for the degradation. The degradation processes of tetracycline HCl and famotidine were highly dependent on the pH of the solution, and relatively stable profiles were achieved at pH 4.0. No potential incompatibility between the drugs under storage conditions was observed in the development of a new multi-drug delivery tablet.

  15. Chromosome studies of bone marrow cells from metronidazole-treated patients.

    PubMed

    Salamanca-Gomez, F; Castaneda, G; Farfan, J; Del C Santillan, M; Munoz, O; Armendares, S

    1980-01-01

    Chromosome studies were performed in bone-marrow cells from thirty nine patients with hepatic or intestinal amibiasis, and/or giardiasis, who had been treated with metronidazole during ten days. There was no significant difference in chromosome aberration frequency between the samples before and after treatment.

  16. Comparison of local metronidazole and a local antiseptic in the treatment of bacterial vaginosis.

    PubMed

    Novakov Mikic, Aleksandra; Budakov, Dragan

    2010-07-01

    Bacterial vaginosis (BV) is characterized by a mixed flora of pathogenic anaerobic bacteria and associated with risks of pathologic conditions. In the present study, therapy with a local antiseptic spray (octenidine hydrochloride/phenoxyethanol, OHP) for 7 or 14 days is compared against the standard local therapy of BV (metronidazole) in a Serbian patient population. As much as 450 women were treated in groups with either 7 days metronidazole vaginal tablets, 7 days OHP, or 14 days OHP. Control smears were taken after each treatment period. In total, 63.2% of the women were without indications of BV after therapy (metronidazole: 61.0%, OHP 7 days: 57.6%, and OHP 14 days: 71.0%). Significantly fewer women were affected from infections after treatment with 14 days OHP compared to OHP for 7 days. Octenidine hydrochloride/phenoxyethanol spray was as effective as the standard therapy with metronidazole. Patients stated that OHP was more comfortable, easier to apply, and side effects were lesser.

  17. A comparative study of oral single dose of metronidazole, tinidazole, secnidazole and ornidazole in bacterial vaginosis.

    PubMed

    Thulkar, Jyoti; Kriplani, Alka; Agarwal, Nutan

    2012-03-01

    To compare the cure rates of oral single dose of metronidazole (2 g), tinidazole (2 g), secnidazole (2 g), and ornidazole (1.5 g) in cases of bacterial vaginosis. This was a prospective, comparative, randomized clinical trial on 344 Indian women (86 women in each group) who attended a gynecology outpatient department with complaint of abnormal vaginal discharge or who had abnormal vaginal discharge on Gynecological examination but they did not complaint of it. For diagnosis and cure rate of bacterial vaginosis, Amsel's criteria were used. Statistical analysis was done by Chi-square test of proportions. The cure rate was compared considering metronidazole cure rate as gold standard. At 1 week, the cure rate of tinidazole and ornidazole was 100% and at 4 weeks, it was 97.7% for both drugs (P<0.001). Secnidazole had cure rate of 80.2% at 4 weeks (P=NS). Metronidazole showed a cure rate of 77.9% at 4 weeks, which is the lowest of all four drugs. Tinidazole and ornidazole have better cure rate as compared to metronidazole in cases of bacterial vaginosis.

  18. Cultivation-independent analysis of changes in bacterial vaginosis flora following metronidazole treatment.

    PubMed

    Ferris, Michael J; Norori, Johana; Zozaya-Hinchliffe, Marcela; Martin, David H

    2007-03-01

    PCR was used to survey bacterial vaginosis flora before and after metronidazole treatment. The species composition for pretreatment patients was variable. Lactobacillus iners was prominent in all patients posttreatment. Atopobium vaginae concentrations were highest for patients who failed or responded incompletely to treatment and lowest for patients who were cured.

  19. Development and Characterization of Bioadhesive Gel of Microencapsulated Metronidazole for Vaginal Use

    PubMed Central

    Bhabani Shankar, Nayak; Prasant Kumar, Rout; Udaya Kumar, Nayak; Benoy Brata, Bhowmik

    2010-01-01

    The present study concerned with the development and characterization of metronidazole microcapsules prepared by thermal change method using different ratios (1:1, 1:2 and 1:4) of ethyl cellulose in order to select the best microcapsule formulation with a good encapsulation efficiency and drug release profile. The obtained microcapsules were discrete, spherical with free flowing properties and evaluated for particle size, shape, flow properties, wall thickness, drug encapsulation efficiency and in vitro release performance. The drug carrier interactions were investigated in solid state by FT-IR spectroscopy and scanning electron microscopy. The microcapsules with a narrow size range of 23-68 μm showed higher encapsulation efficiency. The selected microcapsule formulation, MC3 (Drug polymer ratio 1:4) was employed for gel formulation with a variety of carbopol polymers (carbopol-934, 940, 974 and 980) by mechanical stirring method in order to develop a sustained release microencapsulated metronidazole microcapsules-containing bioadhesive gel. The prepared bioadhesive gels were evaluated for pH, spreadability, extrudability, viscosity, vaginal irritation, in vitro drug release, bioadhesion, accelerated stability and in vitro drug release kinetic. In vitro experiments indicated a sustained release over 24 h and an acceptable bioadhesion quality for formulation F3. Hence, it can be concluded that the formulation F3 has potential to deliver metronidazole in a controlled and constant manner for prolong period over other formulations and can be adopted for a successful delivery of metronidazole for vaginal use. PMID:24363730

  20. Draft Genome Sequence of a Metronidazole-Resistant Derivative of Gardnerella vaginalis Strain ATCC 14019

    PubMed Central

    Schuyler, Jessica A.; Mordechai, Eli; Adelson, Martin E.; Gygax, Scott E.

    2015-01-01

    We report the genome sequence of a metronidazole-resistant derivative of Gardnerella vaginalis ATCC 14019. This strain was obtained after serial selection to increase the MIC from 4 to ≥500 µg/ml. Two coding changes, in genes encoding a response regulator and an NAD+ synthetase, arose during selection. PMID:26564054

  1. Gram stain as a relapse predictor of bacterial vaginosis after metronidazole treatment.

    PubMed

    Huang, Mei; Wang, Jen Hsien

    2005-04-01

    Bacterial vaginosis is the most prevalent disease of the female genital tract. In spite of various effective antibiotics in the treatment of bacterial vaginosis, its high relapse rate is a common problem. Bacterial species causing bacterial vaginosis are generally unable to be cultured by conventional methods. It is impractical and inadequate to use culture methods to guide initial treatment. Gram stain of vaginal secretion is a practical tool to establish the diagnosis of bacterial vaginosis. We enrolled 78 cases of Gram stain-proven bacterial vaginosis and tried to use Gram stain as a predictor of relapse after 1 week of treatment with metronidazole. Possible predictive factors for relapse in Gram stain were analyzed, including absence of large Gram-positive rods, presence of small Gram-negative rods, small Gram-variable rods, curved Gram-variable rods, or Gram-positive cocci. Gram stain was repeated immediately after treatment, and at 1 month and 3 months after treatment. All cases showed beneficial clinical effect after metronidazole treatment. Eighteen cases (23.1%) relapsed during the follow-up period. All 16 cases with significant Gram-positive cocci in pretreatment smears relapsed after metronidazole treatment. Presence of small Gram-negative rods, small Gram-variable rods, and curved Gram-variable rods, or absence of large Gram-positive rods did not predict relapse. Gram-positive cocci in pretreatment smear was a good predictor of relapse after metronidazole treatment.

  2. Metronidazole-induced encephalopathy in a uremic patient: a case report.

    PubMed

    Arik, N; Cengiz, N; Bilge, A

    2001-09-01

    A variety of neurologic disorders may develop in patients with chronic renal failure. Drug toxicity must be thought of in the differential diagnosis of these disorders. We report a case with renal failure developing serious neurotoxicity after metronidazole use. Copyright 2001 S. Karger AG, Basel

  3. Systemic moxifloxacin vs amoxicillin/metronidazole adjunct to non-surgical treatment in generalized aggressive periodontitis

    PubMed Central

    Gurgan, Cem-Abdulkadir

    2015-01-01

    Background The objective of this randomized clinical study was to evaluate the effect of systemic administration of moxifloxacin compared to amoxicillin and metronidazole, combined with non-surgical treatment in patients with generalized aggressive periodontitis (GAgP) in a 6-month follow-up. Material and Methods A total of 39 systemically healthy patients with GAgP were evaluated in this randomized clinical trial. Periodontal parameters were recorded at the baseline during the 1st, 3rd and 6th month. Patients received either 400 mg of moxifloxacin per os once daily or 500 mg of metronidazole and 500 mg amoxicillin per os three times daily for 7 days consecutively. Results No significant differences between groups were found in any parameters at the baseline. Both groups led to a statistically significant decrease in all clinical periodontal parameters compared to the baseline (PI, p<0.001 and GI, PD, BOP, CAL, p<0.01). There were no differences between the 1st and 3rd months or the 3rd and 6th months for clinical parameters in the groups. Also, no intergroup difference was observed in any parameters at any time, except the gingival index at 6th months. Conclusions Systemic administration of moxifloxacin as an adjunct to non-surgical treatment significantly improves clinical outcomes and provides comparable clinical improvement with less adverse events to that of combination of amoxicillin and metronidazole in the treatment of GAgP. Key words: Aggressive periodontitis, amoxicillin, metronidazole, moxifloxacin, nonsurgical periodontal debridement. PMID:26034931

  4. Design and biological evaluation of novel quinolone-based metronidazole derivatives as potent Cu(2+) mediated DNA-targeting antibacterial agents.

    PubMed

    Zhang, Ling; Kumar, Kannekanti Vijaya; Geng, Rong-Xia; Zhou, Cheng-He

    2015-09-01

    A series of novel quinolone-based metronidazole derivatives as new type of antimicrobial agents were developed and characterized. Most of them gave good antibacterial activity towards the Gram-positive and negative bacteria. Noticeably, quinolone derivative 3i exhibited low MIC value of 0.25 μg/mL against Pseudomonas aeruginosa, which was even superior to reference drugs Norfloxacin, Ciprofloxacin and Clinafloxacin. The further research revealed that compound 3i could intercalate into P. aeruginosa DNA through copper ion bridge to form a steady 3i-Cu(2+)-DNA ternary complex which might further block DNA replication to exert the powerful bioactivities.

  5. Metronidazole and hydroxymetronidazole central nervous system distribution: 1. microdialysis assessment of brain extracellular fluid concentrations in patients with acute brain injury.

    PubMed

    Frasca, Denis; Dahyot-Fizelier, Claire; Adier, Christophe; Mimoz, Olivier; Debaene, Bertrand; Couet, William; Marchand, Sandrine

    2014-01-01

    The distribution of metronidazole in the central nervous system has only been described based on cerebrospinal fluid data. However, extracellular fluid (ECF) concentrations may better predict its antimicrobial effect and/or side effects. We sought to explore by microdialysis brain ECF metronidazole distribution in patients with acute brain injury. Four brain-injured patients monitored by cerebral microdialysis received 500 mg of metronidazole over 0.5 h every 8 h. Brain dialysates and blood samples were collected at steady state over 8 h. Probe recoveries were evaluated by in vivo retrodialysis in each patient for metronidazole. Metronidazole and OH-metronidazole were assayed by high-pressure liquid chromatography, and a noncompartmental pharmacokinetic analysis was performed. Probe recovery was equal to 78.8% ± 1.3% for metronidazole in patients. Unbound brain metronidazole concentration-time curves were delayed compared to unbound plasma concentration-time curves but with a mean metronidazole unbound brain/plasma AUC0-τ ratio equal to 102% ± 19% (ranging from 87 to 124%). The unbound plasma concentration-time profiles for OH-metronidazole were flat, with mean average steady-state concentrations equal to 4.0 ± 0.7 μg ml(-1). This microdialysis study describes the steady-state brain distribution of metronidazole in patients and confirms its extensive distribution.

  6. Metronidazole and Hydroxymetronidazole Central Nervous System Distribution: 1. Microdialysis Assessment of Brain Extracellular Fluid Concentrations in Patients with Acute Brain Injury

    PubMed Central

    Frasca, Denis; Dahyot-Fizelier, Claire; Adier, Christophe; Mimoz, Olivier; Debaene, Bertrand; Couet, William

    2014-01-01

    The distribution of metronidazole in the central nervous system has only been described based on cerebrospinal fluid data. However, extracellular fluid (ECF) concentrations may better predict its antimicrobial effect and/or side effects. We sought to explore by microdialysis brain ECF metronidazole distribution in patients with acute brain injury. Four brain-injured patients monitored by cerebral microdialysis received 500 mg of metronidazole over 0.5 h every 8 h. Brain dialysates and blood samples were collected at steady state over 8 h. Probe recoveries were evaluated by in vivo retrodialysis in each patient for metronidazole. Metronidazole and OH-metronidazole were assayed by high-pressure liquid chromatography, and a noncompartmental pharmacokinetic analysis was performed. Probe recovery was equal to 78.8% ± 1.3% for metronidazole in patients. Unbound brain metronidazole concentration-time curves were delayed compared to unbound plasma concentration-time curves but with a mean metronidazole unbound brain/plasma AUC0–τ ratio equal to 102% ± 19% (ranging from 87 to 124%). The unbound plasma concentration-time profiles for OH-metronidazole were flat, with mean average steady-state concentrations equal to 4.0 ± 0.7 μg ml−1. This microdialysis study describes the steady-state brain distribution of metronidazole in patients and confirms its extensive distribution. PMID:24277041

  7. Reducing surgical site infections after hysterectomy: metronidazole plus cefazolin compared with cephalosporin alone.

    PubMed

    Till, Sara R; Morgan, Daniel M; Bazzi, Ali A; Pearlman, Mark D; Abdelsattar, Zaid; Campbell, Darrell A; Uppal, Shitanshu

    2017-08-01

    Organisms that are isolated from vaginal cuff infections and pelvic abscesses after hysterectomy frequently include anaerobic vaginal flora. Metronidazole has outstanding coverage against nearly all anaerobic species, which is superior to both cefazolin and second-generation cephalosporins. Cefazolin plus metronidazole has been demonstrated to reduce infectious morbidity compared with either cefazolin or second-generation cephalosporins in other clean-contaminated procedures, which include both as colorectal surgery and cesarean delivery. The purpose of this study was to evaluate whether the combination of cefazolin plus metronidazole before hysterectomy was more effective in the prevention of surgical site infection than existing recommendations of cefazolin or second-generation cephalosporin. This was a retrospective cohort study of patients in the Michigan Surgical Quality Collaborative from July 2012 through February 2015. The primary outcome was surgical site infection. Patients who were >18 years old and who underwent abdominal, vaginal, laparoscopic, or robotic hysterectomy for benign or malignant indications were included if they received 1 of the following prophylactic antibiotic regimens: cefazolin, second-generation cephalosporin, or cefazolin plus metronidazole. Multivariate logistic regression modeling was performed to evaluate the independent effect of an antibiotic regimen, and propensity score matching was used to validate the findings. The study included 18,255 hysterectomies. The overall rate of surgical site infection was 1.8% (n=329). The unadjusted rate of surgical site infection was 1.8% (n=267) for cefazolin, 2.1% (n=49) for second-generation cephalosporin, and 1.4% (n=13) for cefazolin plus metronidazole. After adjustment for differences in patient and operative factors among the antibiotic cohorts, compared with cefazolin plus metronidazole, we found the risk of surgical site infection was significantly higher for patients who received

  8. Waste Material of Propolis as a Film Forming Agent Intended to Modify the Metronidazole Release: Preparation and Characterization.

    PubMed

    de Toledo, Lucas de Alcântara Sica; Rosseto, Hélen Cássia; Ravani, Laura; Cortesi, Rita; Bruschi, Marcos Luciano

    2016-01-01

    Metronidazole is an antimicrobial agent utilized for the treatment of protozoa and anaerobic bacteria infections. Many times, it is necessary to modify the metronidazole release, and the development of modified release systems may be suggested. In this study, we are able to investigate the use of the residue normally thrown out from the preparation of propolis extracts (BP) as strategy to modify the metronidazole release. We prepared films containing polymeric adjuvant (gelatin or ethylcellulose) and metronidazole, by solvent casting method. Density, mechanical properties, water vapor permeability (WVP), moisture uptake capacity (MUC), thermogravimetry, differential scanning calorimetry, Fourier transform infrared spectroscopy (FT-IR), and in vitro metronidazole release were investigated. Thickness and density of the preparations indicated that the compounds were homogeneously dispersed throughout. Mechanical properties were influenced by film composition. Films containing gelatin showed higher resistance to stress while those containing ethylcellulose presented greater flexibility. The greater the adjuvant concentrations lower the resistance to rupture and the elasticity, but higher MUC and WVP of formulations. FT-IR tests suggested interactions between BP and the adjuvants. Films were capable to protect the metronidazole and changed its release profile. BP films are of great practical importance constituting a novel strategy to modify the metronidazole release.

  9. Stability of cefazolin sodium and metronidazole at 8 degrees C for use as an i.v. admixture.

    PubMed

    Rivers, T E; McBride, H A; Trang, J M

    1993-01-01

    The stability of cefazolin 1 g in metronidazole 500 mg/100 mL at 8 degrees C was studied for use as an IV admixture. The commercially available injection of cefazolin sodium 1 g vial was diluted to 5 mL with 0.9% sodium chloride injection and added to metronidazole 500 mg/100 mL. Following dilution of 2 mL to 100 mL with water, 1-mL aliquots were transferred to glass vials, refrigerated at 8 degrees, and assayed for cefazolin and metronidazole concentration at 0, 1, 2, 4, 8, 12, 24, 36, 48, and 72 hours after preparation. The concentration of cefazolin and metronidazole was determined by a stability-indicating high-performance liquid chromatographic method. The range of concentration was determined to be within 5% of the 0-hour mean concentration. Over the 72-hour period, the mean concentration of cefazolin at all assay times was within 98.4 to 101.0% of the initial concentration. The mean concentration of metronidazole at each assay time was 96.9 to 104.9% of the initial concentration. Cefazolin sodium 10 mg/mL and metronidazole 5 mg/mL, prepared by adding reconstituted cefazolin to a glass bottle of metronidazole ready-to-use solution, were stable for 72 hours when stored at 8 degrees C.

  10. Metronidazole susceptibility testing for Helicobacter pylori: comparison of disk, broth, and agar dilution methods and their clinical relevance.

    PubMed Central

    DeCross, A J; Marshall, B J; McCallum, R W; Hoffman, S R; Barrett, L J; Guerrant, R L

    1993-01-01

    Since the methods for metronidazole susceptibility testing of Helicobacter pylori have not been standardized or validated, we compared three methods that are used to test the metronidazole susceptibilities of 25 isolates of H. pylori. Specifically, we examined the methods of Steer's replicator agar dilution, tube broth microdilution, and modified Kirby-Bauer disk diffusion. The metronidazole disk zone sizes obtained by the disk diffusion method correlated well (r = 0.74) with the MICs obtained by the agar dilution method. Afterward, the disk diffusion method was used to characterize the metronidazole susceptibilities of 44 isolates of H. pylori. Dual therapy (bismuth and metronidazole) proved to be highly effective against metronidazole-susceptible strains (81.6% eradication rate) but fared poorly against resistant strains (16.7% eradication rate; P < 0.01). Using agar dilution testing, we validated the modified Kirby-Bauer disk diffusion method for metronidazole susceptibility testing of H. pylori and conclude that it is practical, accurate, and clinically applicable. PMID:8370723

  11. The role of single-shot metronidazole in the prevention of Clostridium difficile infection following ileostomy reversal surgery.

    PubMed

    Fernandes, Roland; Robinson, Paul; Rangarajan, Karan; Scott, Sophie; Angco, Laura

    2017-05-01

    Symptomatic infection with Clostridium difficile is strongly linked to antibiotic use and rates are higher for colorectal surgery. In February 2015, trust policy for antibiotic prophylaxis of ileostomy reversal surgery was changed from three doses of metronidazole plus cefuroxime to single-dose metronidazole, in a bid to reduce rates of Clostridium difficile infection. A retrospective cohort study was conducted at a single, large hospital trust between February 2014 and February 2016, before and after change in antimicrobial policy. Theatre data, clinical notes and pathology results were all reviewed. Outcome data, patient age, gender, length of operation and hospital stay were extracted. One hundred three patients underwent ileostomy reversal surgery between February 2014 and February 2015. All received cefuroxime together with metronidazole at induction of anaesthesia followed by two further post-operative doses as operative prophylaxis. Ninety-six patients underwent ileostomy reversal surgery between February 2015 and February 2016. All received single-dose metronidazole at induction as prophylaxis. Post-operative diarrhoea was significantly reduced in patients given single-dose metronidazole compared with patients managed with multiple dose, dual antibiotic therapy (32 vs 12.5%, P 0.001). Rates of CDI were also significantly reduced in patients given single-dose metronidazole (6.8 vs 1%, P 0.038). Single-dose, pre-operative metronidazole is effective at reducing post-operative diarrhoea and CDI in ileostomy reversal surgery compared with multiple-dose cefuroxime plus metronidazole. Metronidazole may be effective as a prophylactic antibiotic against CDI in colonic surgery.

  12. Effect of oral administration of metronidazole or prednisolone on fecal microbiota in dogs.

    PubMed

    Igarashi, Hirotaka; Maeda, Shingo; Ohno, Koichi; Horigome, Ayako; Odamaki, Toshitaka; Tsujimoto, Hajime

    2014-01-01

    Gastrointestinal microbiota have been implicated in the pathogenesis of various gastrointestinal disorders in dogs, including acute diarrhea and chronic enteropathy. Metronidazole and prednisolone are commonly prescribed for the treatment of these diseases; however, their effects on gastrointestinal microbiota have not been investigated. The objective of this study was to evaluate the effects of these drugs on the gastrointestinal microbiota of dogs. Metronidazole was administered twice daily at 12.5 mg/kg to a group of five healthy dogs, and prednisolone at 1.0 mg/kg daily to a second group of five healthy dogs for 14 days. Fecal samples were collected before and after administration (day 0 and 14), and 14 and 28 days after cessation (day 28 and 42). DNA was extracted, and the bacterial diversity and composition of each sample were determined based on 16S ribosomal RNA (rRNA) gene sequences using next-generation sequencing (Illumina MiSeq). In the group administered metronidazole, bacterial diversity indices significantly decreased at day 14, and recovered after the cessation. Principal coordinates analysis and hierarchical dendrogram construction based on unweighted and weighted UniFrac distance matrices revealed that bacterial composition was also significantly altered by metronidazole at day 14 compared with the other time points. The proportions of Bacteroidaceae, Clostridiaceae, Fusobacteriaceae, Lachnospiraceae, Ruminococcaceae, Turicibacteraceae, and Veillonellaceae decreased, while Bifidobacteriaceae, Enterobacteriaceae, Enterococcaceae, and Streptococcaceae increased at day 14 and returned to their initial proportions by day 42. Conversely, no effect of prednisolone was observed on either the bacterial diversity or composition. Reducing pathogenic bacteria such as Fusobacteria and increasing beneficial bacteria such as Bifidobacterium through the administration of metronidazole may be beneficial for promoting gastrointestinal health; however, further

  13. Age-Stratified Treatment Response Rates in Hospitalized Patients with Clostridium difficile Infection Treated with Metronidazole.

    PubMed

    Pham, Vy P; Luce, Andrea M; Ruppelt, Sara C; Wei, Wenjing; Aitken, Samuel L; Musick, William L; Roux, Ryan K; Garey, Kevin W

    2015-10-01

    Consensus on the optimal treatment of Clostridium difficile infection (CDI) is rapidly changing. Treatment with metronidazole has been associated with increased clinical failure rates; however, the reasons for this are unclear. The purpose of this study was to assess age-related treatment response rates in hospitalized patients with CDI treated with metronidazole. This was a retrospective, multicenter cohort study of hospitalized patients with CDI. Patients were assessed for refractory CDI, defined as persistent diarrhea after 7 days of metronidazole therapy, and stratified by age and clinical characteristics. A total of 242 individuals, aged 60 ± 18 years (Charlson comorbidity index, 3.8 ± 2.4; Horn's index, 1.7 ± 1.0) were included. One hundred twenty-eight patients (53%) had severe CDI. Seventy patients (29%) had refractory CDI, a percentage that increased from 22% to 28% and to 37% for patients aged less than 50 years, for patients from 50 to 70 years, and for patients aged >70 years, respectively (P = 0.05). In multivariate analysis, Horn's index (odds ratio [OR], 2.04; 95% confidence interval [CI], 1.50 to 2.77; P < 0.001), severe CDI (OR, 2.25; 95% CI, 1.15 to 4.41; P = 0.018), and continued use of antibiotics (OR, 2.65; 95% CI, 1.30 to 5.39; P = 0.0072) were identified as significant predictors of refractory CDI. Age was not identified as an independent risk factor for refractory CDI. Therefore, hospitalized elderly patients with CDI treated with metronidazole had increased refractory CDI rates likely due to increased underlying severity of illness, severity of CDI, and concomitant antibiotic use. These results may help identify patients that may benefit from alternative C. difficile treatments other than metronidazole. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  14. Effect of Oral Administration of Metronidazole or Prednisolone on Fecal Microbiota in Dogs

    PubMed Central

    Ohno, Koichi; Horigome, Ayako; Odamaki, Toshitaka; Tsujimoto, Hajime

    2014-01-01

    Gastrointestinal microbiota have been implicated in the pathogenesis of various gastrointestinal disorders in dogs, including acute diarrhea and chronic enteropathy. Metronidazole and prednisolone are commonly prescribed for the treatment of these diseases; however, their effects on gastrointestinal microbiota have not been investigated. The objective of this study was to evaluate the effects of these drugs on the gastrointestinal microbiota of dogs. Metronidazole was administered twice daily at 12.5 mg/kg to a group of five healthy dogs, and prednisolone at 1.0 mg/kg daily to a second group of five healthy dogs for 14 days. Fecal samples were collected before and after administration (day 0 and 14), and 14 and 28 days after cessation (day 28 and 42). DNA was extracted, and the bacterial diversity and composition of each sample were determined based on 16S ribosomal RNA (rRNA) gene sequences using next-generation sequencing (Illumina MiSeq). In the group administered metronidazole, bacterial diversity indices significantly decreased at day 14, and recovered after the cessation. Principal coordinates analysis and hierarchical dendrogram construction based on unweighted and weighted UniFrac distance matrices revealed that bacterial composition was also significantly altered by metronidazole at day 14 compared with the other time points. The proportions of Bacteroidaceae, Clostridiaceae, Fusobacteriaceae, Lachnospiraceae, Ruminococcaceae, Turicibacteraceae, and Veillonellaceae decreased, while Bifidobacteriaceae, Enterobacteriaceae, Enterococcaceae, and Streptococcaceae increased at day 14 and returned to their initial proportions by day 42. Conversely, no effect of prednisolone was observed on either the bacterial diversity or composition. Reducing pathogenic bacteria such as Fusobacteria and increasing beneficial bacteria such as Bifidobacterium through the administration of metronidazole may be beneficial for promoting gastrointestinal health; however, further

  15. Age-Stratified Treatment Response Rates in Hospitalized Patients with Clostridium difficile Infection Treated with Metronidazole

    PubMed Central

    Pham, Vy P.; Luce, Andrea M.; Ruppelt, Sara C.; Wei, Wenjing; Aitken, Samuel L.; Musick, William L.; Roux, Ryan K.

    2015-01-01

    Consensus on the optimal treatment of Clostridium difficile infection (CDI) is rapidly changing. Treatment with metronidazole has been associated with increased clinical failure rates; however, the reasons for this are unclear. The purpose of this study was to assess age-related treatment response rates in hospitalized patients with CDI treated with metronidazole. This was a retrospective, multicenter cohort study of hospitalized patients with CDI. Patients were assessed for refractory CDI, defined as persistent diarrhea after 7 days of metronidazole therapy, and stratified by age and clinical characteristics. A total of 242 individuals, aged 60 ± 18 years (Charlson comorbidity index, 3.8 ± 2.4; Horn's index, 1.7 ± 1.0) were included. One hundred twenty-eight patients (53%) had severe CDI. Seventy patients (29%) had refractory CDI, a percentage that increased from 22% to 28% and to 37% for patients aged less than 50 years, for patients from 50 to 70 years, and for patients aged >70 years, respectively (P = 0.05). In multivariate analysis, Horn's index (odds ratio [OR], 2.04; 95% confidence interval [CI], 1.50 to 2.77; P < 0.001), severe CDI (OR, 2.25; 95% CI, 1.15 to 4.41; P = 0.018), and continued use of antibiotics (OR, 2.65; 95% CI, 1.30 to 5.39; P = 0.0072) were identified as significant predictors of refractory CDI. Age was not identified as an independent risk factor for refractory CDI. Therefore, hospitalized elderly patients with CDI treated with metronidazole had increased refractory CDI rates likely due to increased underlying severity of illness, severity of CDI, and concomitant antibiotic use. These results may help identify patients that may benefit from alternative C. difficile treatments other than metronidazole. PMID:26195522

  16. Development and Evaluation of Biodegradable Chitosan Films of Metronidazole and Levofloxacin for the Management of Periodontitis.

    PubMed

    Khan, Gayasuddin; Yadav, Sarita K; Patel, Ravi R; Nath, Gopal; Bansal, Monika; Mishra, Brahmeshwar

    2016-12-01

    Metronidazole (MZ) and levofloxacin (LF) are widely employed for treatment of periodontitis, but high oral dose and resistance development after long-term oral administration limit their use. The aim of this study was to alleviate shortcomings in the treatment of periodontitis by fabrication of intrapocket, biodegradable films of chitosan (CS) loaded with MZ and LF meant for inserting into periodontal pockets to treat infections. The films were developed by solvent casting technique using propylene glycol as plasticizer and glutaraldehyde as crosslinking agent. Their physical characteristics, such as drug content, surface pH, swelling index, and folding endurance, exhibited results within limit. Further, FTIR and DSC studies revealed stability of films and compatibility between drugs and excipients. SEM images of films showed the presence of free drug particles on the surface causing burst effect. In vitro release in McIlvaine buffer pH 6.6 was of sustained nature assisted by the burst effect. CS and crosslinking agent concentrations negatively affected drug release and positively affected T90 (time for releasing 90% of the drug) due to altered matrix density. In contrast, the plasticizer concentration increases membrane permeability and hence increased drug release, lowering T90. Crosslinked films demonstrated sustained release up to 7 days. The antibacterial efficacy of films was tested on Staphylococcus aureus and Escherichia coli, indicating good antibacterial activity. Clinical trials on patients proved the therapeutic efficacy of the films by a significant (p < 0.05) decrease in the clinical markers of periodontitis, i.e. gingival index, plaque index and pocket depth. Conclusively, the films of MZ and LF were successful tools for the management of periodontitis.

  17. A Helicobacter pylori TolC Efflux Pump Confers Resistance to Metronidazole

    PubMed Central

    van Amsterdam, Karin; Bart, Aldert; van der Ende, Arie

    2005-01-01

    In Helicobacter pylori, the contribution of efflux proteins to antibiotic resistance is not well established. As translocases that act in parallel may have overlapping substrate specificities, the loss of function of one such translocase may be compensated for by that of another translocase with no effect on susceptibilities to antibiotics. The genome of H. pylori 26695 was assessed for the presence of putative translocases and outer membrane efflux or TolC-like proteins which could interact to form efflux systems involved in drug resistance. Twenty-seven translocases were identified, of which HP1184 was the sole representative of the multidrug and toxic compound extrusion family of translocases and which could thus have a unique substrate specificity. In addition, four TolC-like proteins (HP0605, HP0971, HP1327, and HP1489) were identified. Thus, it is feasible that inactivation of a TolC-like protein would affect the functions of multiple translocases. We aimed to determine whether efflux systems contribute to antimicrobial susceptibility by evaluation of the susceptibility profiles of an HP1184-knockout mutant, four mutants in which one of the four TolC homologs was inactivated, as well as a mutant in which both HP0605 and HP0971 were inactivated. The HP1184- and HP1489-knockout mutants both showed increased susceptibilities to ethidium bromide, while the HP0605-knockout mutant exhibited increased susceptibilities to novobiocin and sodium deoxycholate. The HP0605 and HP0971 double-knockout mutant was also more susceptible to metronidazole, in addition to being susceptible to novobiocin and sodium deoxycholate. Thus, active efflux is an eminent means of resistance to antimicrobials in H. pylori and resembles the situation in other bacteria. PMID:15793129

  18. Comparative Evaluation of Propolis, Metronidazole with Chlorhexidine, Calcium Hydroxide and Curcuma Longa Extract as Intracanal Medicament Against E.faecalis– An Invitro Study

    PubMed Central

    Nair, Rashmi; Asrani, Hemant

    2015-01-01

    Introduction The increase of potential side effects and safety concerns of conventional medicaments have led to the recent popularity of herbal alternative medications. The herbal products are known for its high antimicrobial activity, biocompatibility, anti-inflammatory and antioxidant properties. Aim The purpose of this study was to investigate and compare the effectiveness of Propolis, Metronidazole with Chlorhexidine gel, Curcuma Longa and Calcium Hydroxide for elimination of E.faecalis bacteria in extracted teeth samples. Materials and Methods Ninety extracted single rooted intact teeth were taken for the study. Decoronation, removal of apices and chemomechanical preparation was done for all samples. These sterilized samples were then contaminated with pure culture of E.faecalis under laminar flow. The samples were incubated for a period of 21 days. The infected samples were assigned to 5 groups: Group I- Propolis; Group II- Metronidazole with Chlorhexidine gel; Group III- Calcium hydroxide; Group IV- Curcuma Longa; and control group- Saline. Efficacy of newer intracanal medicaments against E.faecalis were carried out in the samples at the end of 1, 2 & 5 days for each group with the help of colorimeter. Student paired t-test, ANOVA and multiple tukey test were used for statistical analysis. Results The value of optical density was statistically significant in all groups when compared to that of control group. Group I (Propolis) produced better antimicrobial efficacy followed by Chlorhexidine Metronidazole combination, Curcuma Longa and Calcium hydroxide. Conclusion Within the limitations of this study, it can be concluded that Propolis showed better antimicrobial properties against E.faecalis than other medicaments. PMID:26673857

  19. [In vitro anti-Trichomonas vaginalis effects of a mixture of dihydroartemisinin and metronidazole].

    PubMed

    Tang, Zi-Hao; Liu, Ke-Yue; Mei, Jun; Gao, Xing-Zheng

    2010-12-30

    To observe the effect of a mixture of dihydroartemisinin and metronidazole on ultrastructure of Trichomonas vaginalis trophozoites in vitro for exploring trichomonacidal mechanism of the drug mixture. The trophozoites were cultivated with liver extract solution medium that contained 2.5 x 10(6) parasites/ml. There were dihydroartemisinin 0.5 mg/ml and metronidazole 0.002 mg/ml in the experimental tubes of the drug mixture group. Groups of control (without drug), dihydroartemisinin (1 mg/ml) and metronidazole (5 mg/ml) were established and performed in the same experimental conditions. The parasites were observed by scanning and transmission electron microscopes after having treated with the drugs at 37 degrees for 3.5-5 h. Under scanning electron microscope, the cell membrane of T. vaginalis treated only with dihydroartemisinin for 35 h was damaged, part of pellicle peeled off. Although the surface of the trophozoites treated only with metronidazole for 5 h showed many small bubbles and hollows, the cell membrane looked integral. However, surface of the parasite exposed to the drug mixture for 3.5-4.2 h showed deep folds and cracks, the cell membrane was damaged and even peeled off. When the cell ruptured, the nucleus, axostyle, pelta and hydrogenosomes were exposed, and the cytoplasm spilled out. Transmission electron microscopy showed that the membrane system of the trophozoites treated only with dihydroartemisinin for 3.5 h was damaged considerably. The cytoplasm of damaged parasite spilled out. The cytoplasm of the parasite treated only with metronidazole for 3.5-5 h was damaged seriously. Vacuoles and crevices were visible in the cytoplasm. The cell membrane and the content of the parasites treated with the drug mixture for 3.5-4.5 h were damaged seriously. There were some vacuoles and crevices, dilated endoplasmic reticulum, injured and deformed hydrogenosomes in the cytoplasm. The cell organelles mostly disappeared. Crevices also existed in the nucleus. The

  20. Experience of successful treatment of patients with metronidazole-resistant Trichomonas vaginalis with zinc sulfate: A case series.

    PubMed

    Byun, Jung Mi; Jeong, Dae Hoon; Kim, Young Nam; Lee, Kyung Bok; Sung, Moon Su; Kim, Ki Tae

    2015-10-01

    There are no universally successful guidelines for the treatment of metronidazole-resistant vaginal trichomoniasis. This is distressing for patients and frustrating for physicians. We therefore decided to evaluate whether zinc sulfate douche is effective in treating vaginal trichomoniasis, because the compound is a natural antimicrobial chemical defense in humans. In our retrospective case review, eight cases of metronidazole-resistant trichomoniasis were treated with 1% zinc sulfate douche with or without tinidazole between 2005 and 2012. Except for one patient who was pregnant, seven patients were successfully treated and were negative for microscopic findings with no clinical symptoms at follow up. Although the exact role of zinc sulfate in metronidazole-resistant trichomoniasis is not clear, our patients experienced a therapeutic effect with zinc sulfate douche treatment. We therefore recommend zinc sulfate douche as an option for the treatment of metronidazole-resistant vaginal trichomoniasis. Copyright © 2015. Published by Elsevier B.V.

  1. Comparing the therapeutic effects of garlic tablet and oral metronidazole on bacterial vaginosis: a randomized controlled clinical trial.

    PubMed

    Mohammadzadeh, Farnaz; Dolatian, Mahrokh; Jorjani, Masoome; Alavi Majd, Hamid; Borumandnia, Nasrin

    2014-07-01

    Bacterial vaginosis (BV) is one of the most common gynecological infections during reproductive age. Although metronidazole is one of the most effective medications recommended as the first-line treatment, it has various side effects. Because of the side effects and contraindications of some chemical medicines, using herbs has been investigated in treating BV. The aim of this study was to compare the effect of garlic tablet (Garsin) and oral metronidazole in clinical treatment of the BV in women referred to Resalat Health Center, affiliated with Mazandaran University of Medical Sciences, in 2013. This randomized clinical trial was conducted on 120 married women aged 18 to 44 years who were diagnosed with BV by Amsel's clinical criteria and Gram staining. Enrolled women were randomly allocated to two groups of 60 patients and were treated with either garlic tablet or oral metronidazole for seven days. Amsel's criteria and Gram stain were assessed seven to ten days after beginning the treatment period and side effects were registered. Amsel's criteria were significantly decreased after treatment with garlic or metronidazole (70% and 48.3%, respectively; P < 0.001). Therapeutic effects of garlic on BV were similar to that of metronidazole (63.3% and 48.3%, respectively; P = 0.141). There were significant differences between the two treatment groups in terms of side effects; metronidazole was associated with more complications (P = 0.032). This study reveals that garlic could be a suitable alternative for metronidazole in treatment of BV in those interested in herbal medicines or those affected by side effects of metronidazole.

  2. Cumulative irritation potential of metronidazole gel compared to azelaic acid gel after repeated applications to healthy skin.

    PubMed

    Ziel, Kristin; Yelverton, Christopher B; Balkrishnan, Rajesh; Feldman, Steven R

    2005-01-01

    Metronidazole 0.75% gel and azelaic acid 15% gel are commonly used to treat rosacea. Irritation is a common side effect. To assess the cumulative irritation potential of metronidazole 0.75% gel and azelaic acid 15% gel. Metronidazole 0.75% gel, azelaic acid 15% gel, and a white petrolatum negative control were applied under occlusive conditions to the upper back of a total of 33 healthy subjects. There were twelve 24-hour applications (4 times a week) and three 72-hour applications on weekends during a 3-week period. Skin reactions (erythema score +/- other local reaction) were assessed within 15 to 30 minutes of removal of the products. The mean cumulative irritancy index of metronidazole 0.75% gel was significantly lower than that of azelaic acid 15% gel and not significantly higher than the negative control product. There was increasing cumulative irritancy with azelaic acid; no cumulative irritancy was seen for either metronidazole or white petrolatum. Metronidazole 0.75% gel is less irritating in sustained use than azelaic acid 15% gel.

  3. Effect of pentachlorophenol on the activation of 2,6-dinitrotoluene to genotoxic urinary metabolites in CD-1 mice: A comparison of G1 enzyme activities and urine mutagenicity

    SciTech Connect

    George, S.E.; Chadwick, R.W.; Creason, J.P.; Kohan, M.J. ); Dekker, J.P. )

    1991-01-01

    2,6-Dinitrotoluene (2,6-DNT) and pentachlorophenol (PCP) are used for industrial purposes and are found in the environment as hazardous contaminants. Because concurrent exposure to both compounds can occur, it is of interest to determine if organochlorine compounds potentiate the effect of nitroaromatic chemicals. A significant increase in mutagenicity was observed in urines from mice treated with 2,6-DNT alone and in combination with PCP. By week 4, mice that received both 2,6-DNT and PCP excreted urine that was more mutagenic than that from animals which received only 2,6-DNT. At weeks 2 and 4, mice were sacrificed and intestinal enzyme activities (nitroreductase, azo reductase, {beta}-glucuronidase, dechlorinase, and dehydrochlorinase) were quantitated. The enhanced genotoxicity observed in urines from 2,6-DNT/PCP-treated mice coincided with a decrease in nitroreductase and an increase in {beta}-glucuronidase activities in the small intestine.

  4. Metronidazole in the treatment of cervical cancer using Cf-252 neutron brachytherapy

    SciTech Connect

    Maruyama, Y.

    1986-01-01

    Metronidazole was tested for its possible use in the Cf-252 brachytherapy of cervical cancer as a radiosensitizer and to deal with anaerobic pelvic infection. 15 patients were treated by only 14 were evaluable. All stages from stage IB-IVB were treated and complete local tumor regression was noted in all cases although it could take place very slowly. 5/14 (36%) are 1.5-3 year survivors but only among the patients with stage I-II disease. No unusual radio-enhancing action was observed but metronidazole appeared to be useful to treat the vaginal, cervix and uterine infections often associated with high stage disease and bulky, ulcerative or necrotic tumors.

  5. Common products from gamma-radiolysis and ultraviolet photolysis of metronidazole

    NASA Astrophysics Data System (ADS)

    Moore, Douglas E.; Wilkins, Brian J.

    u.v. Photolysis of metronidazole in aqueous solution at pH 7.0 results in rearrangement through an imino-ketone to an oxadiazole. These compounds were also found following γ-radiolysis of metronidazole, being about 10% of the products. Saturation of the solution with nitrous oxide caused a slight increase in the yield of imino-ketone in radiolysis. Conversely, the imino-ketone was not detected on addition of sodium formate or propan-2-ol to the radiolysis, but an increased yield of other products was observed. It is suggested that formation of the imino-ketone and oxadiazole in both photolysis and radiolysis occurs via processes which do not involve the nitro radical anion as first transient species.

  6. Generation of radical anions of nitrofurantoin, misonidazole, and metronidazole by ascorbate.

    PubMed

    Rao, D N; Harman, L; Motten, A; Schreiber, J; Mason, R P

    1987-06-01

    Nitrofurantoin, misonidazole, and metronidazole were reduced to their corresponding nitro anion radicals by ascorbate in anaerobic solutions at high pH. The nitrofurantoin anion radical could be detected at neutral pH. In neutral solutions, the nitro anion radicals of misonidazole and metronidazole were too unstable to be observed by electron spin resonance spectroscopy. At neutral pH, solutions containing ascorbate, nitrofurantoin, or misonidazole consumed oxygen. The addition of superoxide dismutase, catalase, or both superoxide dismutase and catalase decreased the rate of oxygen consumption. These results show that nitro anion radicals are formed by reduction with ascorbate, and superoxide anion radical and hydrogen peroxide are produced by reactions of these radicals with oxygen.

  7. Evaluation of the fluid uptake kinetics and drug release from gellan gum tablets containing metronidazole.

    PubMed

    Emeje, M O; Franklin-Ude, P I; Ofoefule, S I

    2010-08-01

    In this study, the fluid uptake (swelling) kinetics and disintegrant properties of gellan gum in metronidazole tablets were evaluated in both simulated gastric and intestinal fluids (SGF and SIF respectively) without enzymes. The mechanical properties as well as the disintegration and dissolution profile of the tablets were also assessed and compared with those of two standard disintegrants: maize starch and sodium starch glycolate (Primogel). Results show that, swelling was faster and higher in SIF than SGF with the minimum and maximum swelling rates of the gum being 0.365 and 6.900 mm(3)/min respectively in SGF, while the corresponding values in SIF were 0.277 and 7.600 mm(3)/min respectively. The gum was most effective as a disintegrant for metronidazole tablets at an optimum concentration of 0.2% (w/w) when incorporated extra-granularly.

  8. The effects of intravaginal clindamycin and metronidazole therapy on vaginal lactobacilli in patients with bacterial vaginosis.

    PubMed

    Nyirjesy, Paul; McIntosh, Matthew J; Gattermeir, David J; Schumacher, Robert J; Steinmetz, Jana I; Joffrion, James L

    2006-05-01

    The purpose of this study was to determine the effects of 3 intravaginal antibacterial treatments on vaginal lactobacilli in patients with bacterial vaginosis (BV). Retrospective analyses were performed on Lactobacillus scores from 3 similar studies evaluating 2 2% clindamycin vaginal creams and 0.75% metronidazole gel at baseline and at 21 to 30 days in 408 patients with BV. Scores were compared using a 1-way global F test and McNemar's test. All groups had similar mean Lactobacillus scores at baseline (P = 0.37) and at 21 to 30 days (P = .71). The 3 groups were also comparable at both visits with respect to the distributions of scores within each group. In all groups, there was significant improvement in the percentages of patients with no lactobacilli present at 21 to 30 days compared with baseline (P < .0001 for all comparisons). Clindamycin and metronidazole promoted similar levels of restoration of vaginal lactobacilli at 21 to 30 days.

  9. Entamoeba histolytica and Trichomonas vaginalis: trophozoite growth inhibition by metronidazole electro-transferred water.

    PubMed

    Heredia-Rojas, J Antonio; Torres-Flores, Antonio Cayetano; Rodríguez-De la Fuente, Abraham O; Mata-Cárdenas, Benito David; Rodríguez-Flores, Laura E; Barrón-González, María Porfiria; Torres-Pantoja, Antonio Cayetano; Alcocer-González, Juan M

    2011-01-01

    The influence of low-frequency electromagnetic (LF-EM) waves on microorganisms has been a subject of experimental investigations for more than two decades and the results are promising. In parallel, an interesting procedure known as biophysical-information-therapy or bioresonance therapy (BRT) which in principle is based on LF-EM stimulation, has emerged. BRT was discovered in the late 1980's but it is still poorly studied. This paper demonstrates that by transferring metronidazole information to water samples by an electronic amplifier (BRT device), the growth of axenically cultured trophozoites of Entamoeba histolytica and Trichomonasvaginalis is significantly inhibited, compared with those cultures treated with non and sham electro-transferred water samples. A positive control of metronidazole, a well-known cytotoxic drug against parasites, was used as a reference. Copyright © 2010 Elsevier Inc. All rights reserved.

  10. Metronidazole as a radiosensitizer: a preliminary report on estimation in serum and saliva

    SciTech Connect

    Karim, A.B.M.F.; Faber, D.B.; Haas, R.E.; Hoekstra, F.H.; Njo, K.H.

    1980-09-01

    Some studies indicate the clinical benefit of hypoxic radiosensitizers in patients who are undergoing radiotherapy. Serum level of sensitizers are usualy advised; however they are very demanding on the patient. Saliva level of the sensitizers may be an alternative method. This study correlated serum level of metronidazole to the saliva level in 10 patients who were undergoing radiotherapy with the sensitizer. A change to the saliva level method appears to relieve the patients.

  11. Metronidazole immediate release formulations: a fasting randomized open-label crossover bioequivalence study in healthy volunteers.

    PubMed

    de Freitas Silva, M; Schramm, S G; Kano, E K; Koono, E E M; Manfio, J L; Porta, V; dos Reis Serra, C H

    2012-10-01

    Metronidazole is a BCS (Biopharmaceutics Classification System) class 1 drug, traditionally considered the choice drug in the infections treatment caused by protozoa and anaerobic microorganisms. This study aimed to evaluate bioequivalence between 2 different marketed 250 mg metronidazole immediate release tablets. A randomized, open-label, 2×2 crossover study was performed in healthy Brazilian volunteers under fasting conditions with a 7-day washout period. The formulations were administered as single oral dose and blood was sampled over 48 h. Metronidazole plasma concentrations were determined by a liquid chromatography mass spectrometry (LC-MS/MS) method. The plasma concentration vs. time profile was generated for each volunteer and the pharmacokinetic parameters Cmax, Tmax, AUC0-t, AUC0-∞, ke, and t1/2 were calculated using a noncompartmental model. Bioequivalence between pharmaceutical formulations was determined by calculating 90% CIs (Confidence Intervall) for the ratios of Cmax, AUC0-t, and AUC0-∞ values for test and reference using log-transformed data. 22 healthy volunteers (11 men, 11 women; mean (SD) age, 28 (6.5) years [range, 21-45 years]; mean (SD) weight, 66 (9.3) kg [range, 51-81 kg]; mean (SD) height, 169 (6.5) cm [range, 156-186 cm]) were enrolled in and completed the study. The 90% CIs for Cmax (0.92-1.06), AUC0-t (0.97-1.02), and AUC0-∞ (0.97-1.03) values for the test and reference products fitted in the interval of 0.80-1.25 proposed by most regulatory agencies, including the Brazilian agency ANVISA. No clinically significant adverse effects were reported. After pharmacokinetics analysis, it concluded that test 250 mg metronidazole formulation is bioequivalent to the reference product according to the Brazilian agency requirements. © Georg Thieme Verlag KG Stuttgart · New York.

  12. Aspirin increases susceptibility of Helicobacter pylori to metronidazole by augmenting endocellular concentrations of antimicrobials.

    PubMed

    Zhang, Xiao-Ping; Wang, Wei-Hong; Tian, Yu; Gao, Wen; Li, Jiang

    2009-02-28

    To investigate the mechanisms of aspirin increasing the susceptibility of Helicobacter pylori (H pylori) to metronidazole. H pylori reference strain 26695 and two metronidazole-resistant isolates of H pylori were included in this study. Strains were incubated in Brucella broth with or without aspirin (1 mmol/L). The rdxA gene of H pylori was amplified by PCR and sequenced. The permeability of H pylori to antimicrobials was determined by analyzing the endocellular radioactivity of the cells after incubated with [7-(3)H]-tetracycline. The outer membrane proteins (OMPs) of H pylori 26695 were depurated and analyzed by SDS-PAGE. The expression of 5 porins (hopA, hopB, hopC, hopD and hopE) and the putative RND efflux system (hefABC) of H pylori were analyzed using real-time quantitative PCR. The mutations in rdxA gene did not change in metronidazole resistant isolates treated with aspirin. The radioactivity of H pylori increased when treated with aspirin, indicating that aspirin improved the permeability of the outer membrane of H pylori. However, the expression of two OMP bands between 55 kDa and 72 kDa altered in the presence of aspirin. The expression of the mRNA of hopA, hopB, hopC, hopD, hopE and hefA, hefB, hefC of H pylori did not change when treated with aspirin. Although aspirin increases the susceptibility of H pylori to metronidazole, it has no effect on the mutations of rdxA gene of H pylori. Aspirin increases endocellular concentrations of antimicrobials probably by altering the OMP expression.

  13. Aspirin increases susceptibility of Helicobacter pylori to metronidazole by augmenting endocellular concentrations of antimicrobials

    PubMed Central

    Zhang, Xiao-Ping; Wang, Wei-Hong; Tian, Yu; Gao, Wen; Li, Jiang

    2009-01-01

    AIM: To investigate the mechanisms of aspirin increasing the susceptibility of Helicobacter pylori (H pylori) to metronidazole. METHODS: H pylori reference strain 26 695 and two metronidazole-resistant isolates of H pylori were included in this study. Strains were incubated in Brucella broth with or without aspirin (1 mmol/L). The rdxA gene of H pylori was amplified by PCR and sequenced. The permeability of H pylori to antimicrobials was determined by analyzing the endocellular radioactivity of the cells after incubated with [7-3H]-tetracycline. The outer membrane proteins (OMPs) of H pylori 26 695 were depurated and analyzed by SDS-PAGE. The expression of 5 porins (hopA, hopB, hopC, hopD and hopE) and the putative RND efflux system (hefABC) of H pylori were analyzed using real-time quantitative PCR. RESULTS: The mutations in rdxA gene did not change in metronidazole resistant isolates treated with aspirin. The radioactivity of H pylori increased when treated with aspirin, indicating that aspirin improved the permeability of the outer membrane of H pylori. However, the expression of two OMP bands between 55 kDa and 72 kDa altered in the presence of aspirin. The expression of the mRNA of hopA, hopB, hopC, hopD, hopE and hefA, hefB, hefC of H pylori did not change when treated with aspirin. CONCLUSION: Although aspirin increases the susceptibility of H pylori to metronidazole, it has no effect on the mutations of rdxA gene of H pylori. Aspirin increases endocellular concentrations of antimicrobials probably by altering the OMP expression. PMID:19248190

  14. Metronidazole Resistance in Prevotella spp. and Description of a New nim Gene in Prevotella baroniae▿

    PubMed Central

    Alauzet, C.; Mory, F.; Teyssier, C.; Hallage, H.; Carlier, J. P.; Grollier, G.; Lozniewski, A.

    2010-01-01

    Nonduplicate clinical isolates of Prevotella spp. recovered from patients hospitalized between 2003 and 2006 in two French tertiary-care teaching hospitals were investigated for their susceptibility to metronidazole and the presence of nim genes. Of the 188 strains tested, 3 isolates displayed reduced susceptibility to metronidazole after 48 h of incubation, while 27 additional isolates exhibited heterogeneous resistance after prolonged incubation; all 30 of the isolates were nim negative. Among the remaining 158 isolates, 7 nim-positive isolates were detected. All of these strains were identified as Prevotella baroniae by 16S rRNA gene sequence analysis and contained a new nim gene, named nimI, as determined by DNA sequence analysis. Chromosomal localization of this single-copy gene was demonstrated in all clinical isolates as well as in type strain P. baroniae DSM 16972 by using Southern hybridization. No known associated insertion sequence elements were detected upstream of the nimI gene in any of the nim-positive strains by PCR mapping. After prolonged exposure to metronidazole, stable resistant subpopulations could be selected in nimI-positive Prevotella isolates (n = 6) as well as in nim-negative Prevotella isolates (n = 6), irrespective of their initial susceptibility to this antibiotic. This study is the first description of a new nitroimidazole resistance gene in P. baroniae which seems to be silent and which might be intrinsic in this species. Moreover, our findings highlight the fact that high-level resistance to metronidazole may be easily induced in both nim-positive and nim-negative Prevotella sp. strains. PMID:19805556

  15. The role of Bacteroides fragilis RecQ DNA helicases in cell survival after metronidazole exposure.

    PubMed

    Paul, Lynthia; Patrick, Sheila; Nord, Carl Erik; Abratt, Valerie

    2011-06-01

    The inactivation of Bacteroides fragilis genes encoding putative RecQ helicases recQ1, recQ2 and recQ3 (ORFs BF638R_3282, BF638R_3781, BF638R_3932) was used to determine whether these proteins are involved in cell survival following metronidazole exposure. The effects of the mutations on growth, cellular morphology and DNA integrity were also evaluated. Mutations in the RecQ DNA helicases caused increased sensitivity to metronidazole, with recQ1, recQ2 and recQ3 mutants being 1.32-fold, 41.88-fold and 23.18-fold more sensitive than the wild type, respectively. There was no difference in cell growth between the recQ1 and recQ3 mutants and the wild type. However, the recQ2 mutant exhibited reduced cell growth, aberrant cell division and increased pleiomorphism, with an increase in filamentous forms and chains of cells being observed using light, fluorescence and electron microscopy. There was no spontaneous accumulation of DNA single- or double-strand breaks in the recQ mutants, as compared with the wild type, during normal cell growth in the absence of metronidazole. Bacteroides fragilis RecQ DNA helicases, therefore, enhance cell survival following metronidazole damage. The abnormal cellular phenotype and growth characteristics of recQ2 mutant cells suggest that this gene, or the downstream gene of the operon in which it occurs, may be involved in cell division.

  16. Increase number of mitochondrion-like organelle in symptomatic Blastocystis subtype 3 due to metronidazole treatment.

    PubMed

    Raman, Kalyani; Kumar, Suresh; Chye, Tan Tian

    2016-01-01

    Blastocystis sp., an intestinal organism is known to cause diarrhea with metronidazole regarded as the first line of treatment despite reports of its resistance. The conflicting reports of variation in drug treatment have been ascribed to subtype differences. The present study evaluated in vitro responses due to metronidazole on ST3 isolated from three symptomatic and asymptomatic patients, respectively. Symptomatic isolates were obtained from clinical patients who showed symptoms such as diarrhea and abdominal bloating. Asymptomatic isolates from a stool survey carried out in a rural area. These patients had no other pathogens other than Blastocystis. Ultrastructural studies using transmission electron microscopy (TEM) and scanning electron microscopy (SEM) revealed drug-treated ST3 from symptomatic patients were irregular and amoebic with surface showing high-convoluted folding when treated with metronidazole. These organisms had higher number of mitochondrion-like organelle (MLO) with prominent cristae. However, the drug-treated ST3 from asymptomatic persons remained spherical in shape. Asymptomatic ST3 showed increase in the size of its central body with the MLO located at the periphery.

  17. Evaluation of early fetal exposure to vaginally-administered metronidazole in pregnant cynomolgus monkeys.

    PubMed

    Thompson, Kary E; Newcomb, Deanna L; Moffat, Graeme J; Zalikowski, Julie; Chellman, Gary J; McNerney, Mary Ellen

    2016-01-01

    Given concern about potential embryo-fetal harm following seminal exposure to drugs with teratogenic potential, pharmaceutical companies use theoretical calculations to estimate seminal concentrations, maternal exposure, and distribution across the placenta to the embryo-fetal compartment for risk assessment. However, it is plausible that there are additional mechanisms whereby the conceptus is exposed. In order to determine if theoretical calculations are sufficiently conservative to predict embryo-fetal exposure from drugs in semen, pregnant cynomolgus monkeys were given a vaginal dose of metronidazole during the early fetal period and cesarean-sectioned. Maternal, fetal, and amniotic fluid samples were analyzed for metronidazole and 2-hydroxymetronidazole. Exposure to metronidazole and its metabolite were comparable in all matrices. These data demonstrated no preferential transfer mechanism to conceptus following intravaginal administration of a small molecule drug; and therefore, suggest that traditional modeling for embryo-fetal exposure to drugs in semen in support of risk assessment for pharmaceutical agents is sufficiently conservative. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Development of Floating-Mucoadhesive Microsphere for Site Specific Release of Metronidazole

    PubMed Central

    Amin, Md. Lutful; Ahmed, Tajnin; Mannan, Md. Abdul

    2016-01-01

    Purpose: The purpose of this study was to develop and evaluate metronidazole loaded floating-mucoadhesive microsphere for sustained drug release at the gastric mucosa. Methods: Alginate gastroretentive microspheres containing metronidazole were prepared by ionic gelation method using sodium bicarbonate as gas forming agent, guar gum as mucoadhesive polymer, and Eudragit L100 as drug release modifier. Carbopol was used for increasing the bead strength. The microspheres were characterized by scanning electron microscopy and evaluated by means of drug entrapment efficiency, in vitro buoyancy, and swelling studies. In vitro mucoadhesion and drug release studies were carried out in order to evaluate site specific sustained drug release. Results: All formulations showed 100% buoyancy in vitro for a prolonged period of time. Amount of guar gum influenced the properties of different formulations. The formulation containing drug and guar gum at a ratio of 1:0.5 showed the best results with 76.3% drug entrapment efficiency, 61.21% mucoadhesion, and sustained drug release. Carbopol was found to increase surface smoothness of the microspheres. Conclusion: Metronidazole mucoadhesive-floating microspheres can be effectively used for sustained drug release to the gastric mucosa in treatment of upper GIT infection. PMID:27478781

  19. Treatment of asymptomatic amebiasis in homosexual men. Clinical trials with metronidazole, tinidazole, and diloxanide furoate.

    PubMed

    Thorén, K; Håkansson, C; Bergström, T; Johanisson, G; Norkrans, G

    1990-01-01

    In a randomized trial, the authors treated 42 asymptomatic homosexual men who had Entamoeba histolytica in fecal specimens with either metronidazole or tinidazole (study 1). They treated both groups initially with 2,000 mg in a single dose, and in case of failure with 2,000 mg daily for 5 days. In cases of repeated failure, the authors prescribed a dosage of 500 mg of diloxanide furoate three times per day (TID) for 10 days. In a subsequent study (study 2) the authors treated 49 asymptomatic homosexual men who had E. histolytica in fecal specimens with 500 mg of diloxanide furoate TID for 10 days. In study 1, the parasitological cure rates (PCR) for metronidazole and tinidazole were 29%-56%. Among the men treated with diloxanide furoate, the PCR was 93%. In study 2 the PCR with diloxanide furoate was 88%, which was significantly better (P less than .05) than metronidazole/tinidazole treatment in study 1. The present studies show that diloxanide furoate is an effective treatment of amebiasis in asymptomatic patients.

  20. Clinical and Neuroradiological Spectrum of Metronidazole Induced Encephalopathy: Our Experience and the Review of Literature

    PubMed Central

    Panwar, Ajay; Pandit, Alak; Das, Susanta Kumar; Joshi, Bhushan

    2016-01-01

    Metronidazole is an antimicrobial agent mainly used in the treatment of several protozoal and anaerobic infections, additionally, is often used in hepatic encephalopathy and Crohn disease. Apart from peripheral neuropathy, metronidazole can also cause symptoms of central nervous system dysfunction like ataxic gait, dysarthria, seizures, and encephalopathy which may result from both short term and chronic use of this drug and is collectively termed as “metronidazole induced encephalopathy”(MIE). Neuroimaging forms the backbone in clinching the diagnosis of this uncommon entity, especially in cases where there is high index of suspicion of intoxication. Although typical sites of involvement include cerebellum, brain stem and corpus callosum, however, lesions of other sites have also been reported. Once diagnosed, resolution of findings on Magnetic Resonance Imaging (MRI) of the Brain along with clinical improvement remains the mainstay of monitoring. Here we review the key clinical features and MRI findings of MIE as reported in medical literature. We also analyze implication of use of this drug in special situations like hepatic encephalopathy and brain abscess and discuss our experience regarding this entity. PMID:27504340

  1. The treatment of Gardnerella vaginalis vaginosis: a randomized comparison of pivampicillin with metronidazole.

    PubMed

    Csángó, P A; Jagars, G; Tommelstad, T

    1985-01-01

    The efficacy of pivampicillin and metronidazole were compared in the treatment of Gardnerella vaginalis associated bacterial vaginosis. In a multicenter trial 86 women were given pivampicillin (P) 700 mg twice daily for 6 days and 86 women received metronidazole (M) 400 mg three times daily for 7 days. At control, 2 weeks from the start of treatment, patients in group P showed the best clinical results, 77.9% in group P vs. 64.0% in group M (p = 0.066). P showed a higher clinical efficacy than M, both in women using intra-uterine device and in patients using other forms of contraception. Negative post-treatment cultures were seen in 43% of women in group P and 64% in group M (p less than 0.002). Bacteriological cure was unrelated to disappearance of discharge, odour and itching, although it correlated significantly with a negative amine test (p less than 0.00005). Pivampicillin in the dosages used in the present investigation is a useful alternative to metronidazole therapy.

  2. Changes in the vaginal microenvironment with metronidazole treatment for bacterial vaginosis in early pregnancy.

    PubMed

    Mitchell, Caroline; Balkus, Jennifer; Agnew, Kathy; Lawler, Richard; Hitti, Jane

    2009-11-01

    Bacterial vaginosis (BV) is associated with preterm delivery, but there is little evidence that treatment improves pregnancy outcomes. We examined whether oral or vaginal metronidazole treatment for BV in early pregnancy was more effective in restoring the normal vaginal environment. This was a randomized controlled trial comparing oral and intravaginal metronidazole for treatment of BV in early pregnancy (<20 weeks). Vaginal samples collected at baseline and 4 weeks after treatment were evaluated using gram stain, culture, colorimetric detection of sialidase, and immunoassay for measurement of proinflammatory cytokines interleukins-1beta, -6, -8 (IL-1beta, IL-6, IL-8) and secretory leukocyte protease inhibitor (SLPI). We compared the effect of treatment between groups (using chi-square and t test) and within individuals (McNemar's test). Of 126 subjects, 108 (86%) completed follow-up (55 oral, 53 intravaginal). Of the study population, 34% achieved therapeutic cure, and this was not different between treatment groups. BV-associated bacteria were significantly reduced in both groups, but few subjects regained colonization with protective lactobacilli. Among women who achieved therapeutic cure, the level of IL-1beta dropped significantly (p < 0.001) and SLPI increased (p = 0.003). More women in the vaginal treatment group had undetectable sialidase after treatment (p = 0.013). Treatment with oral or intravaginal metronidazole in early pregnancy reduced colonization with BV-associated bacteria but was not effective in achieving therapeutic cure or in restoring healthy vaginal lactobacilli.

  3. Metronidazole or Cotrimoxazole Therapy Is Associated with a Decrease in Intestinal Bioavailability of Common Antiretroviral Drugs

    PubMed Central

    Dossou-Yovo, Flore; Mamadou, Godefroy; Soudy, Imar Djibrine; Limas-Nzouzi, Nicolas; Miantezila, Joe; Desjeux, Jehan-François; Eto, Bruno

    2014-01-01

    Metronidazole (MTZ) and Cotrimoxazole (CTX) are used in HIV/AIDS patients eligible for antiretroviral treatment. The objective of this animal study was to determine whether pre-treatment with antibiotics affects the intestinal bioavailability of Atazanavir (ATV) and Ritonavir (RTV). After oral administration of 1 mg MTZ and CTX for 7 days, the rat colonic mucosa were analyzed for mucus thickness or placed in Ussing chambers to measure ATV and RTV net transepithelial fluxes (Jnet). 1. In control rats, the mucus thickness was 43.3±7.6 µm and 40.7±6.9 µm, in proximal and distal colon, respectively. In proximal colon, the thickness was 57.2±8.8 and 58.2±6.9 µm after MTZ and CTX, respectively whereas in distal colon, the thickness was 121.1±38.4 and 170.5±35.0 µm (P<0.05) respectively. 2. Transepithelial conductance was reduced after MTZ or CTX in the proximal and distal colon. 3. In control, net ATV secretion was observed both in proximal (−0.36±0.02 µg.hr−1 cm−2) and distal colon (−0.30±0.08 µg.hr−1 cm−2). After MTZ and CTX, it was increased in the proximal colon by two 2 fold and 4 fold, respectively and in the distal colon by 3 fold and 5 fold, respectively. 4. In control, there was no net active RTV transport either in proximal (+0.01±0.01 µg.hr−1 cm−2) or distal colon (+0.04±0.01 µg.hr−1 cm−2). After MTZ and CTX, secretion was increased 5 fold and 10 fold, respectively, in the proximal colon and two fold and 5 fold, respectively in the distal colon (p<0.001). In conclusion, after MTZ and CTX therapy, the mucus layer was enlarged, passive permeability was decreased and ATV and RTV were actively secreted by the colonic epithelium suggesting that, in rat, the intestinal bioavailability of ATV and RTV is impaired after antibiotic therapy. PMID:24587140

  4. Metronidazole or Cotrimoxazole therapy is associated with a decrease in intestinal bioavailability of common antiretroviral drugs.

    PubMed

    Dossou-Yovo, Flore; Mamadou, Godefroy; Soudy, Imar Djibrine; Limas-Nzouzi, Nicolas; Miantezila, Joe; Desjeux, Jehan-François; Eto, Bruno

    2014-01-01

    Metronidazole (MTZ) and Cotrimoxazole (CTX) are used in HIV/AIDS patients eligible for antiretroviral treatment. The objective of this animal study was to determine whether pre-treatment with antibiotics affects the intestinal bioavailability of Atazanavir (ATV) and Ritonavir (RTV). After oral administration of 1 mg MTZ and CTX for 7 days, the rat colonic mucosa were analyzed for mucus thickness or placed in Ussing chambers to measure ATV and RTV net transepithelial fluxes (Jnet). 1. In control rats, the mucus thickness was 43.3±7.6 µm and 40.7±6.9 µm, in proximal and distal colon, respectively. In proximal colon, the thickness was 57.2±8.8 and 58.2±6.9 µm after MTZ and CTX, respectively whereas in distal colon, the thickness was 121.1±38.4 and 170.5±35.0 µm (P<0.05) respectively. 2. Transepithelial conductance was reduced after MTZ or CTX in the proximal and distal colon. 3. In control, net ATV secretion was observed both in proximal (-0.36±0.02 µg.hr(-1) cm(-2)) and distal colon (-0.30±0.08 µg.hr(-1) cm(-2)). After MTZ and CTX, it was increased in the proximal colon by two 2 fold and 4 fold, respectively and in the distal colon by 3 fold and 5 fold, respectively. 4. In control, there was no net active RTV transport either in proximal (+0.01±0.01 µg.hr(-1) cm(-2)) or distal colon (+0.04±0.01 µg.hr(-1) cm(-2)). After MTZ and CTX, secretion was increased 5 fold and 10 fold, respectively, in the proximal colon and two fold and 5 fold, respectively in the distal colon (p<0.001). In conclusion, after MTZ and CTX therapy, the mucus layer was enlarged, passive permeability was decreased and ATV and RTV were actively secreted by the colonic epithelium suggesting that, in rat, the intestinal bioavailability of ATV and RTV is impaired after antibiotic therapy.

  5. A model system for measuring comparative toxicities of cardiotoxic drugs with cultured rat heart myocytes, endothelial cells and fibroblasts. I. Emetine, chloroquine and metronidazole.

    PubMed

    Wenzel, D G; Cosma, G N

    1984-11-01

    Neonatal rat hearts were separated into separate cultures of beating myocytes (M cells), endothelial cells (E cells) and fibroblasts (F cells). Their susceptibilities to the toxic effects of emetine, chloroquine and metronidazole were then compared using a quantitative metabolic inhibition test (QMIT) and morphologic and beating changes as indices of injury. Measurements on the same cultures were made at 6 h and 12 h daily for 7 days with E and F cells; with M cells for 3 days. Metronidazole was non-toxic for all cell types at 810 micrograms/ml, whether as the parent compound or after attempted rat liver microsomal activation. QMIT data, integrated as time-concentration effects, showed all cell responses to either emetine or chloroquine to be parallel (P less than 0.05), and their order of susceptibility to be: E greater than M greater than F cells. Although morphologic signs of injury and changes in beating are not readily evaluated statistically, there was a general parallelism between these indices of injury and those of QMIT. As judged by QMIT emetine was more toxic than chloroquine. However, at equivalent QMIT grades chloroquine produced greater effects on morphology and beating. Toxic concentration-50 values for chloroquine with the QMIT were similar to reported human toxic and lethal blood concentrations.

  6. Reinvestigation of in vivo genotoxicity studies in man. I. No induction of DNA strand breaks in peripheral lymphocytes after metronidazole therapy.

    PubMed

    Fahrig, R; Engelke, M

    1997-12-12

    Although a rodent carcinogen, metronidazole is widely used in humans for the treatment of infections with anaerobic organisms. Metronidazole is mutagenic for microorganisms, but has a mainly negative data base for mammals and humans. Therefore, metronidazole is generally considered as a non-genotoxic carcinogen. Only the results of two human in vivo studies would allow the classification of metronidazole as genotoxic carcinogen: (1) the induction of DNA strand breaks; and (2) the induction of chromosome aberrations in peripheral lymphocytes after metronidazole therapy. Because the classification of metronidazole as genotoxic carcinogen would imply enormous consequences with respect to its application, both studies were reinvestigated very thoroughly. The present report describes the reinvestigation of the induction of DNA strand breaks after metronidazole therapy. Each two probes of lymphocytes of metronidazole-treated patients (3 x 500 to 3 x 750 mg/day for 5-8 days) were examined separately for the appearance of DNA strand breaks before and after treatment. In total, 400 nuclei were examined per patient. Immediately before the first, and 30 min to 2 h after the last application, 2 x 10 ml blood per patient was sampled, transported to the laboratory at 15-20 degrees C to make DNA repair more difficult, and examined within the next 4-7 h for DNA strand breaks. At the same time, the individual metronidazole blood plasma levels were measured. In contrast to the published reports, no induction of DNA strand breaks after metronidazole therapy could be observed in the present study. As the applied doses (15,750 mg vs. 4800 mg) and the plasma level (up to 25 micrograms/ml vs. not measured) of metronidazole were much higher than in the published study, the relevance of the clearly negative result is obvious. As induction of DNA strand breaks is a frequent prerequisite for genotoxicity, metronidazole should be considered as a non-genotoxic carcinogen, and not as a

  7. Comparison of cefixime and amoxicillin plus metronidazole in the treatment of chronic periodontitis.

    PubMed

    Dukić, Smiljka; Matijević, Stevo; Daković, Dragana; Cutović, Tatjana

    2016-06-01

    Despite significant advances in current medicine and improvement of overall health education, chronic periodontitis is still a widespread disease. Losing teeth is the most serious complication of this particular illness. The aim of this study was to examine patients with chronic periodontitis in order to evaluate the efficacy of non-surgical therapy and combination of amoxicillin and metronidazole compared with cefixime, which has not been so far used for the treatment of this disease. Adult patients with chronic periodontitis (n = 90) underwent non-surgical periodontal treatment (zero-day) and then randomly divided into three groups. The group I served as a control, the group II was additionally treated with the combination of amoxicillin and metronidazole (for 7 days), while the group III was treated with cefixime (also for 7 days). To assess the condition of periodontium before and seven days after the therapy, four clinical parameters were used: gingival index (GI), bleeding on probing (BOP), probing depth (PD) and clinical attachment level (CAL). On the day 7 after the beginning of the therapy, we found that all the three groups of patients had statistically significant clinical improvement of three parameters: GI, BOP and PD, but not of the CAL. However, the improvement of PD was only statistically, but not clinically significant. The improvement in the control group of patients on the day 7 was 19% in BOP and 28% in GI; this improvement was statistically highly significant after the addition of amoxicillin plus metronodazole (71% in BOP and 77% in GI) or cefixime (62% in BOP and 82% in GI). Compared to the combination of amoxicillin and metronidazole, cefixim was statistically significantly more effective for GI (p < 0.05), while for the other three clinical parameters their effects were equal. The conjunction of amoxicillin plus metronidazole or cefixime to the causal treatment of patients with chronic periodontitis led to statistically significant

  8. [The first metronidazole-resistant Bacteroides species isolated at Marmara University Hospital: Bacteroides thetaiotaomicron].

    PubMed

    Toprak Ülger, Nurver; Sayın, Elvan; Soyad, Ad; Dane, Faysal; Söyletir, Güner

    2013-10-01

    Bacteroides species, the predominant constituents of the human intestinal microbiota can cause serious intraabdominal and postoperative wound infections and bacteremia. Moreover, these bacteria are more resistant to antimicrobial agents than the other anaerobes. The limited number of the antimicrobials, such as carbapenems, beta-lactam/beta-lactamase inhibitors and nitroimidazoles are highly effective in eliminating Bacteroides. However, a few metronidazole-resistant isolates have been reported from several countries recently. The nim genes (nim A-G) are suggested to be responsible for the majority of the metronidazole resistance. Here, we describe a metronidazole-resistant Bacteroides thetaiotaomicron isolated from a blood culture. A gram-negative obligate anaerobic rod was isolated from the postoperative 5th day blood culture of a 62-year-old male patient with adenocarcinoma of the pancreas head. The strain was identified as B.thetaiotaomicron by using a combination of conventional tests and commercially available biochemical kits. Antimicrobial susceptibility testing was performed by agar dilution method. The resistance genes were investigated by means of PCR using specific primer pairs for nim gene. The purified PCR product was sequenced and analyzed by comparison of the consensus sequences with GenBank sequences. The MIC for metronidazole was 16 mg/L. Although the strain was intermediate according the CLSI criteria, it was resistant (> 4 mg/L) according to EUCAST criteria. The isolate was nim gene positive, and nucleotide sequencing of the PCR product shared 100% similarity with nimE gene (emb |AM042593.1 |). On the other hand the isolate was susceptible to carbapenems and sulbactam-ampicillin. Following administration of ampicillin-sulbactam, the patient's fever disappeared after 24 hours. The clinical condition improved considerably and he was discharged at day 8. The patient was followed up at the medical oncology clinic; however he died due to disease

  9. The appearance of facial foundation cosmetics applied after metronidazole gel 1%.

    PubMed

    Draelos, Zoe D; Colón, Luz E; Preston, Norman; Johnson, Lori A; Gottschalk, Ronald W

    2011-05-01

    The purpose of this study was to assess the cosmetic appearance of commonly marketed facial cosmetics when used after the application of metronidazole gel 1%. An observational. open-label, single-site study was conducted with women (N=30) aged 20 to 75 years and diagnosed with moderate papulopustular rosacea (investigator global severity score of 3). After cleansing the face with a gentle skin cleanser, participants applied metronidazole gel 1% once daily before applying their usual facial foundation. Two surveys were conducted: (1) investigator assessment of cosmetic appearance; and (2) participant assessment of cosmetic appearance. The investigator also evaluated erythema, disease severity, and tolerability at baseline and week 2. Adverse events were collected. The 28 per-protocol (PP) participants had a mean age (standard deviation [SD]) of 54.0 (10.3) years and a mean duration (SD) of rosacea of 15.4 (13.2) years. The median response score for both the investigator and participant assessments of cosmetic appearance was 10 (best) for each survey question. Signs and symptoms of rosacea did not increase with use of metronidazole gel 1% and the participants' selected cosmetic regimen. At baseline all 28 participants were classified as having moderate erythema. At week 2, 18 (64%) participants were classified as having moderate erythema and 10 (36%) mild. At baseline all 28 (100%) participants were classified as having moderate rosacea according to the investigator global severity score. At week 2, 10 (36%) participants were classified as mild and 18 (64%) moderate. In addition, few participants reported cutaneous irritation during the study. At week 2, 10 participants had dryness, 2 had itching, 8 had scaling, and 2 had stinging/burning. According to surveys completed by the investigator and the participants themselves, most participants had a good cosmetic appearance with their facial foundation cosmetics that were applied after metronidazole gel 1%. The use of

  10. Development and validation of a liquid chromatography tandem mass spectrometry assay for the measurement of faecal metronidazole.

    PubMed

    Jeffery, Jinny; Vincent, Zoe J; Ayling, Ruth M; Lewis, Stephen J

    2017-04-01

    Metronidazole is an oral antibiotic which is widely used in the treatment of patients with Clostridium difficile associated disease. This article describes the validation of a LC-MS/MS assay for the measurement of metronidazole in human faecal samples. Matrix matched and aqueous standards showed no significant difference in performance for the routine calibration of the assay. D(4) deuterated metronidazole internal standard eluted with a different retention time to the undeuterated metronidazole on chromatography, hence zidovudine was used as an internal standard. Ion suppression was noted for both metronidazole and zidovudine due to unidentified compounds present in the faecal matrix and this was improved by extracting a smaller quantity of faeces and diluting the extract prior to analysis. Measurement uncertainty was 13% at 28,400ng/ml, 7.2% at 3300ng/ml, 3.9% at 320ng/ml, 13.6% at 109ng/ml and 30.9% at 20ng/ml. The assay was shown to be linear on dilution and the sensitivity of the assay was superior to HPLC assays using UV detection. The limit of detection was 5ng/ml, the limit of quantitation was 66ng/ml and the upper limit of the working range was 30,000ng/ml. Patient samples were stable at -20°C for 12months and extracted faecal samples were stable on storage for 1week at 4°C. There were no specific requirements for patient preparation or time of sample collection relative to taking metronidazole. Metronidazole can be quantified in faecal samples using LC-MS/MS which opens up opportunities for further research in this area. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  11. Fourteen-day high-dose esomeprazole, amoxicillin and metronidazole as third-line treatment for Helicobacter pylori infection.

    PubMed

    Puig, Ignasi; González-Santiago, Jesús M; Molina-Infante, Javier; Barrio, Jesús; Herranz, Maria Teresa; Algaba, Alicia; Castro, Manuel; Gisbert, Javier P; Calvet, Xavier

    2017-09-01

    The efficacy of currently recommended third-line therapies for Helicobacter pylori is suboptimal, even that of culture-guided treatments. Resistance to multiple antibiotics is the major factor related to treatment failure. The aim of this study was to evaluate the effectiveness and safety of a 14-day therapy using high-dose of amoxicillin, metronidazole and esomeprazole. Multicenter open-label study as a register in routine clinical practice in patients with two previous failures of eradication therapy. A triple therapy with esomeprazole 40 mg b.d., amoxicillin 1 g t.d.s and metronidazole 500 mg t.d.s for 2 weeks was administered as a third-line therapy after a first treatment including clarithromycin and a second treatment including a quinolone. Helicobacter pylori status was determined by either histology or (13) C-UBT both before and after treatment. A total of 68 patients were included in this study. An interim analysis showed that only three out of eight patients who had received metronidazole in previous eradication regimens were cured (37%, 95% CI 8-75); as a result, after this interim analysis only metronidazole-naïve patients were included. The ITT eradication rate in metronidazole-naive patients was 64% (95% CI 51-76). Adverse events occurred in 58% of patients, all of them mild-to-moderate. Two patients (3%) did not complete >90% of the treatment because of side effects. No severe adverse events occurred. Cure rates of this 14-day schedule using high-dose esomeprazole, amoxicillin and metronidazole as a third-line eradication regimen were suboptimal, especially in patients who had received metronidazole in previous failed eradication regimens. © 2017 John Wiley & Sons Ltd.

  12. In vivo interaction of anti-cancer drugs with misonidazole or metronidazole: methotrexate, 5-fluorouracil and adriamycin.

    PubMed Central

    Tannock, I. F.

    1980-01-01

    I have studied the effects on growth of two tumours in mice and on host toxicity, of combining Misonidazole (MISO) or Metronidazole (METRO) with Methotrexate (MTX)-5-fluorouracil (FU) or Adriamycin (ADR). The nitroimidazoles alone had no effect on the growth of either tumour, but MISO (1 mg/g) led to a small increase in delay to regrowth of the 16/C mammary carcinoma but not the KHT fibrosarcoma, when given after X-irradiation. MTX was active only against the KHT tumour, and growth delay was not increased by the addition of MISO or METRO. FU delayed growth of both tumours, and growth delay was increased slightly by single-dose MISO. ADR was active only against the 16/C tumour, and delay to regrowth was increased by adding MISO. Host toxicity assessed by death and loss of body weight was much greater when MISO or METRO were added to MTX, and a little greater when they were added to FU. ADR plus MISO caused no deaths and no greater loss of body weight than ADR alone. The addition of MISO to treatment with anticancer drugs led to a slightly greater and more prolonged myelosuppression. METRO and MISO increase the anti-tumour effects of some anti-cancer drugs, but may also increase host toxicity. Nitroimidazoles should be used with caution in combination with chemotherapy. PMID:7459220

  13. Therapeutic equivalence requires pharmaceutical, pharmacokinetic, and pharmacodynamic identities: true bioequivalence of a generic product of intravenous metronidazole.

    PubMed

    Agudelo, M; Vesga, O

    2012-05-01

    Animal models of infection have been used to demonstrate the therapeutic failure of "bioequivalent" generic products, but their applicability for this purpose requires the accurate identification of those products that are truly bioequivalent. Here, we present data comparing one intravenous generic product of metronidazole with the innovator product in a neutropenic mouse thigh anaerobic infection model. Simultaneous experiments allowed comparisons (generic versus innovator) of potency and the concentration of the active pharmaceutical ingredient (API), analytical chemistry (liquid chromatography/mass spectrometry [LC/MS]), in vitro susceptibility testing, single-dose serum pharmacokinetics (PK) in infected mice, and in vivo pharmacodynamics (PD) against Bacteroides fragilis ATCC 25825 in synergy with Escherichia coli SIG-1 in the neutropenic mouse thigh anaerobic infection model. The Hill dose-response model followed by curve-fitting analysis was used to calculate and compare primary and secondary PD parameters. The generic and the innovator products were identical in terms of the concentration and potency of the API, chromatographic and spectrographic profiles, MIC and minimal bactericidal concentrations (MBC) (2.0 mg/liter), and mouse PK. We found no differences between products in bacteriostatic doses (BD) (15 to 22 mg/kg of body weight per day) or the doses needed to kill 1 log (1LKD) (21 to 29 mg/kg per day) or 2 logs (2LKD) (28 to 54 mg/kg per day) of B. fragilis under dosing schedules of every 12 h (q12h), q8h, or q6h. The area under the concentration-time curve over 24 h in the steady state divided by the MIC (AUC/MIC ratio) was the best PD index to predict the antibacterial efficacy of metronidazole (adjusted coefficient of determination [AdjR(2)] = 84.6%), and its magnitude to reach bacteriostasis in vivo (56.6 ± 5.17 h) or to kill the first (90.8 ± 9.78 h) and second (155.5 ± 22.2 h) logs was the same for both products. Animal models of infection

  14. Therapeutic Equivalence Requires Pharmaceutical, Pharmacokinetic, and Pharmacodynamic Identities: True Bioequivalence of a Generic Product of Intravenous Metronidazole

    PubMed Central

    Agudelo, M.

    2012-01-01

    Animal models of infection have been used to demonstrate the therapeutic failure of “bioequivalent” generic products, but their applicability for this purpose requires the accurate identification of those products that are truly bioequivalent. Here, we present data comparing one intravenous generic product of metronidazole with the innovator product in a neutropenic mouse thigh anaerobic infection model. Simultaneous experiments allowed comparisons (generic versus innovator) of potency and the concentration of the active pharmaceutical ingredient (API), analytical chemistry (liquid chromatography/mass spectrometry [LC/MS]), in vitro susceptibility testing, single-dose serum pharmacokinetics (PK) in infected mice, and in vivo pharmacodynamics (PD) against Bacteroides fragilis ATCC 25825 in synergy with Escherichia coli SIG-1 in the neutropenic mouse thigh anaerobic infection model. The Hill dose-response model followed by curve-fitting analysis was used to calculate and compare primary and secondary PD parameters. The generic and the innovator products were identical in terms of the concentration and potency of the API, chromatographic and spectrographic profiles, MIC and minimal bactericidal concentrations (MBC) (2.0 mg/liter), and mouse PK. We found no differences between products in bacteriostatic doses (BD) (15 to 22 mg/kg of body weight per day) or the doses needed to kill 1 log (1LKD) (21 to 29 mg/kg per day) or 2 logs (2LKD) (28 to 54 mg/kg per day) of B. fragilis under dosing schedules of every 12 h (q12h), q8h, or q6h. The area under the concentration-time curve over 24 h in the steady state divided by the MIC (AUC/MIC ratio) was the best PD index to predict the antibacterial efficacy of metronidazole (adjusted coefficient of determination [AdjR2] = 84.6%), and its magnitude to reach bacteriostasis in vivo (56.6 ± 5.17 h) or to kill the first (90.8 ± 9.78 h) and second (155.5 ± 22.2 h) logs was the same for both products. Animal models of infection

  15. Simultaneous determination of ranitidine and metronidazole in human plasma using high performance liquid chromatography with diode array detection.

    PubMed

    do Nascimento, Ticiano Gomes; Oliveira, Eduardo de Jesus; Macêdo, Rui Oliveira

    2005-04-01

    The development and validation of a simple method for the simultaneous determination of ranitidine and metronidazole in human plasma is described. Plasma samples (250 microL) were deproteinized by precipitation with 60% perchloric acid, centrifuged and the supernatant directly injected into the HPLC. Separation was achieved in isocratic mode with a Shimpak C(18) column and a mobile phase consisting of 10mM potassium dihydrogen phosphate pH 3.5:acetonitrile (90:10, v/v) with UV detection at 315 nm. The method showed good selectivity and sensitivity. Good and consistent recovery for metronidazole and ranitidine was obtained: 96.22+/-3.52 and 95.00+/-4.50% for ranitidine (25-1000 ng/mL) and metronidazole (60-10,000 ng/mL), respectively (n=3). With this one-step sample preparation method, both ranitidine and metronidazole could be quantified simultaneously in human plasma with good precision (R.S.D.<15%) and accuracy (bias values below 15%). The limit of quantification for ranitidine and metronidazole were 20 and 40 ng/mL plasma, respectively.

  16. Loss of Microbiota-Mediated Colonization Resistance to Clostridium difficile Infection With Oral Vancomycin Compared With Metronidazole.

    PubMed

    Lewis, Brittany B; Buffie, Charlie G; Carter, Rebecca A; Leiner, Ingrid; Toussaint, Nora C; Miller, Liza C; Gobourne, Asia; Ling, Lilan; Pamer, Eric G

    2015-11-15

    Antibiotic administration disrupts the intestinal microbiota, increasing susceptibility to pathogens such as Clostridium difficile. Metronidazole or oral vancomycin can cure C. difficile infection, and administration of these agents to prevent C. difficile infection in high-risk patients, although not sanctioned by Infectious Disease Society of America guidelines, has been considered. The relative impacts of metronidazole and vancomycin on the intestinal microbiota and colonization resistance are unknown. We investigated the effect of brief treatment with metronidazole and/or oral vancomycin on susceptibility to C. difficile, vancomycin-resistant Enterococcus, carbapenem-resistant Klebsiella pneumoniae, and Escherichia coli infection in mice. Although metronidazole resulted in transient loss of colonization resistance, oral vancomycin markedly disrupted the microbiota, leading to prolonged loss of colonization resistance to C. difficile infection and dense colonization by vancomycin-resistant Enterococcus, K. pneumoniae, and E. coli. Our results demonstrate that vancomycin, and to a lesser extent metronidazole, are associated with marked intestinal microbiota destruction and greater risk of colonization by nosocomial pathogens. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  17. Loss of Microbiota-Mediated Colonization Resistance to Clostridium difficile Infection With Oral Vancomycin Compared With Metronidazole

    PubMed Central

    Lewis, Brittany B.; Buffie, Charlie G.; Carter, Rebecca A.; Leiner, Ingrid; Toussaint, Nora C.; Miller, Liza C.; Gobourne, Asia; Ling, Lilan; Pamer, Eric G.

    2015-01-01

    Antibiotic administration disrupts the intestinal microbiota, increasing susceptibility to pathogens such as Clostridium difficile. Metronidazole or oral vancomycin can cure C. difficile infection, and administration of these agents to prevent C. difficile infection in high-risk patients, although not sanctioned by Infectious Disease Society of America guidelines, has been considered. The relative impacts of metronidazole and vancomycin on the intestinal microbiota and colonization resistance are unknown. We investigated the effect of brief treatment with metronidazole and/or oral vancomycin on susceptibility to C. difficile, vancomycin-resistant Enterococcus, carbapenem-resistant Klebsiella pneumoniae, and Escherichia coli infection in mice. Although metronidazole resulted in transient loss of colonization resistance, oral vancomycin markedly disrupted the microbiota, leading to prolonged loss of colonization resistance to C. difficile infection and dense colonization by vancomycin-resistant Enterococcus, K. pneumoniae, and E. coli. Our results demonstrate that vancomycin, and to a lesser extent metronidazole, are associated with marked intestinal microbiota destruction and greater risk of colonization by nosocomial pathogens. PMID:25920320

  18. Validation of a modified Kirby-Bauer disk diffusion method for metronidazole susceptibility testing of Helicobacter pylori.

    PubMed

    Midolo, P D; Turnidge, J; Lambert, J R; Bell, J M

    1995-03-01

    Triple antimicrobial therapy that includes metronidazole has been recommended as a first-line therapy for Helicobacter pylori because it has the highest eradication rates. However, resistance in H. pylori to metronidazole has been reported worldwide and its presence may reduce the efficacy of triple therapy. Various methods for testing H. pylori against metronidazole have been used including agar dilution, disk diffusion and the Etest but there has been little standardization of methods. One hundred isolates of H. pylori from different patients were tested for susceptibility to metronidazole by agar dilution, Etest and disk diffusion (5 micrograms disk). The agar dilution results confirmed the MIC susceptibility breakpoint to be < or = 8 micrograms/ml. Using this breakpoint there was close agreement (98%) between Etest and agar dilution results. For susceptible strains, MICs by E-test were generally one twofold dilution lower. Using the error-rate bounded method, agreement between disk diffusion zone diameter and MIC was 98% for agar dilution with breakpoints of > or = 12 mm and < or = 8 micrograms/ml and 100% for Etest with breakpoints of > or = 12 mm and < or = 8 micrograms/ml. The Etest discriminated better than agar dilution between susceptible and resistant strains and was simple to perform. The disk diffusion test is a reliable and cheaper alternative to the Etest with susceptibility being a zone diameter > or = 12 mm with a 5 micrograms disk. The prevalence of metronidazole resistance in this study was 40% by Etest.

  19. Preparation of novel composites based on hydrophilized and functionalized polyacrylonitrile membrane-immobilized NZVI for reductive transformation of metronidazole

    NASA Astrophysics Data System (ADS)

    Wang, Xiangyu; Liu, Peng; Ma, Jun; Liu, Huiling

    2017-02-01

    For the first time, hydrophilized and functionalized polyacrylonitrile (PAN) membrane was synthesized via two-stage process, addition of polyvinyl alcohol and in situ polymerization of acrylic acid (AA), and nano zero-valent iron (NZVI) was incorporated within modified membrane. The as-prepared PAA/PAN-NZVI (PPN) composites possessed superior reactivity for metronidazole (MNZ) with transformation ratio 2.03 and reaction rate 4.77 times higher than that by bare NZVI. Meanwhile, the enhanced stability and recyclability of PPN composites were maintained over repeated cycles. The major advantages of synthetic method lie in the remarkably increased loading and decreased agglomeration of NZVI. Moreover, with hydrophilized and functionalized synthesis processes of membrane, the potential risk of released iron ions was not a concern due to strong chelation of grafted carboxyl groups. Analyses of morphological characteristics (FE-SEM), chemical structure (FTIR), element valence and groups (XPS) of samples confirmed the successful graft of carboxylic acid groups and formation of a uniform iron nanoparticles coating onto PAN matrix. The reaction kinetics of MNZ with PPN composites were well-described by a two-parameter pseudo-first-order decay model with activation energy of 29.5 kJ/mol. The co-solutes except humic acid had a negligible effect on MNZ transformation. Determination of intermediates revealed that nitro reduction, N-denitration and hydroxyethyl cleavage were the main pathways for transformation of MNZ. The findings suggest that the novel composites possess huge potential for antibiotics wastewater treatment.

  20. Human pharmacokinetics and toxicity of high-dose metronidazole administered orally and intravenously

    SciTech Connect

    Urtasun, R.C.; Rabin, H.R.; Partington, J.

    1983-01-01

    This study is part of a clinical program to assess the use of nitroimidazoles as radiosensitizers of hypoxic tumor cells. A total of 37 patients with malignant tumors have been entered into the study to receive oral high-dose metronidazole in conjunction with radiation. Twenty-eight patients with malignant brain tumors received 6 gm/m2 three times a week for 3 weeks (a mean total dose of 5.3 gm/m2). Maximum mean plasma drug concentration of 1 mM was obtained at 4 hours after drug ingestion with a mean half-life of 13 hours. Tissue and cerebrospinal fluid levels of 80% to 90% of the plasma levels were obtained at 4 to 6 hours. A linear relationship between increased drug dose and increased plasma concentration was observed at doses of 2.5 gm/m2 up to 6 gm/m2. Acute gastrointestinal and central nervous system toxicity was the dose-limiting factor (50% and 25%, respectively, at total doses of 5.3 gm/m2). Pharmacokinetic studies of intravenous metronidazole were performed in eight consenting patients. Single doses of 0.5, 1, 1.5, and 2 gm were administered intravenously by zero-order infusion pump. Seven of the eight patients received a second identical dose orally 1 week later and the results were compared. Open two-compartment kinetic characteristics of metronidazole were computed from simultaneous plasma infusion and urine excretion rate equations, by use of a nonlinear least-squares regression analysis program (NONLIN). The mean (+/- SD) for alpha half-life was 1.2 +/- 1.3 hours, and that for the beta half-life was 9.8 +/- 5.9 hours. The absolute oral bioavailability was estimated to approximate 100%.

  1. Comparative evaluation of locally delivered minocycline and metronidazole in the treatment of periodontitis

    PubMed Central

    Pandit, Nymphea; Dahiya, Ritu; Gupta, Rajan; Bali, Deepika; Kathuria, Abhinav

    2013-01-01

    Objective: The aim of this study was to evaluate and compare the efficacy of subgingivally delivered Minocycline microspheres and 25% Metronidazole gel when used as an adjunct to scaling and root planing (SRP) in the treatment of chronic periodontitis. Materials and Methods: A randomized, controlled, single center study was conducted involving 60 sites in 20 patients suffering from moderate to advanced chronic periodontitis. Each patient contributed three sites which were randomized to three treatment groups: SRP + insertion of Minocycline microspheres at day 1 (Group A), SRP + insertion of Metronidazole gel at day 1 and at day 7 (Group B), and SRP alone (Group C). Gingival index (GI), plaque index (PI), probing pocket depth (PPD), and clinical attachment level (CAL) were recorded at day 1, 1 month, and 3 months post therapy. Results: All treatments showed significant reductions in PPD and CAL at 1 and 3 months when compared to baseline values (P < 0.001). At 3 months, sites treated with minocycline showed an additional reduction in PPD of 0.85 ± 0.03 mm, significantly greater than SRP alone. Differences in mean PPD reduction between Group B and Group C and between Group A and Group B were not significant. At 3 months, difference in CAL gain between Group A and C was 0.50 ± 0.45, which was statistically significant and between Group B and C was 0.35 ± 0.11, which was not found to be statistically significant (P = 0.20). Differences in relative CAL between Group A and Group B were also not found to be statistically significant (P = 0.53). Conclusion: The results concluded that treatment with Minocycline microspheres and Metronidazole gel improve PPD and CAL in patients with periodontitis compared to SRP alone. PMID:23853452

  2. Comparative evaluation of locally delivered minocycline and metronidazole in the treatment of periodontitis.

    PubMed

    Pandit, Nymphea; Dahiya, Ritu; Gupta, Rajan; Bali, Deepika; Kathuria, Abhinav

    2013-01-01

    The aim of this study was to evaluate and compare the efficacy of subgingivally delivered Minocycline microspheres and 25% Metronidazole gel when used as an adjunct to scaling and root planing (SRP) in the treatment of chronic periodontitis. A randomized, controlled, single center study was conducted involving 60 sites in 20 patients suffering from moderate to advanced chronic periodontitis. Each patient contributed three sites which were randomized to three treatment groups: SRP + insertion of Minocycline microspheres at day 1 (Group A), SRP + insertion of Metronidazole gel at day 1 and at day 7 (Group B), and SRP alone (Group C). Gingival index (GI), plaque index (PI), probing pocket depth (PPD), and clinical attachment level (CAL) were recorded at day 1, 1 month, and 3 months post therapy. All treatments showed significant reductions in PPD and CAL at 1 and 3 months when compared to baseline values (P < 0.001). At 3 months, sites treated with minocycline showed an additional reduction in PPD of 0.85 ± 0.03 mm, significantly greater than SRP alone. Differences in mean PPD reduction between Group B and Group C and between Group A and Group B were not significant. At 3 months, difference in CAL gain between Group A and C was 0.50 ± 0.45, which was statistically significant and between Group B and C was 0.35 ± 0.11, which was not found to be statistically significant (P = 0.20). Differences in relative CAL between Group A and Group B were also not found to be statistically significant (P = 0.53). The results concluded that treatment with Minocycline microspheres and Metronidazole gel improve PPD and CAL in patients with periodontitis compared to SRP alone.

  3. Preemptive warfarin dose reduction after initiation of sulfamethoxazole-trimethoprim or metronidazole.

    PubMed

    Powers, Anna; Loesch, Erin B; Weiland, Anthony; Fioravanti, Nicole; Lucius, David

    2017-07-01

    To evaluate the utility of a preemptive warfarin dose reduction at the time of initiation of either sulfamethoxazole-trimethoprim or metronidazole, a retrospective chart review of patients who received an outpatient prescription for warfarin and either sulfamethoxazole-trimethoprim and/or metronidazole from July 1, 2011 to July 1, 2015 was conducted. Clinical outcomes compared Veterans who had a warfarin dose reduction and those who did not within 120 h (5 days) of antibiotic initiation. The primary outcome compared the pre-and post-antibiotic International Normalized Ratio (INR) of patients in the intervention group (warfarin dose reduction) with those in the control group (no intervention). Secondary outcomes assessed incidence of thromboembolic and major bleeding events within 30 days of antibiotic completion. Fifty patients were assessed. Forty-nine patients had at least one follow-up appointment; 126 follow-up visits were evaluated. There was a statistically significant difference for the change in therapeutic INR at the first follow-up appointment (p = 0.029) for those patients in the control group. On average, the patients in the intervention group required fewer follow-up visits (p = 0.019). There were no statistically significant differences for the overall rate of therapeutic INR values between groups, as well as no instances of a thromboembolic or major bleeding events during the follow-up period. Clinically significant differences were observed for patients who received a preemptive warfarin dose reduction upon initiation of sulfamethoxazole-trimethoprim or metronidazole. Patients in the intervention group required fewer follow-up appointments and were more likely maintain a therapeutic INR within the 30 days following the antibiotic course. Results of this study will be presented the at Pharmacy and Therapeutics committee in an effort to seek approval for policy development to initiate a local preemptive warfarin dose adjustment as a standard

  4. Changes in the Vaginal Microenvironment with Metronidazole Treatment for Bacterial Vaginosis in Early Pregnancy

    PubMed Central

    Balkus, Jennifer; Agnew, Kathy; Lawler, Richard; Hitti, Jane

    2009-01-01

    Abstract Objective Bacterial vaginosis (BV) is associated with preterm delivery, but there is little evidence that treatment improves pregnancy outcomes. We examined whether oral or vaginal metronidazole treatment for BV in early pregnancy was more effective in restoring the normal vaginal environment. Methods This was a randomized controlled trial comparing oral and intravaginal metronidazole for treatment of BV in early pregnancy (<20 weeks). Vaginal samples collected at baseline and 4 weeks after treatment were evaluated using gram stain, culture, colorimetric detection of sialidase, and immunoassay for measurement of proinflammatory cytokines interleukins-1β, -6, -8 (IL-1β, IL-6, IL-8) and secretory leukocyte protease inhibitor (SLPI). We compared the effect of treatment between groups (using chi-square and t test) and within individuals (McNemar's test). Results Of 126 subjects, 108 (86%) completed follow-up (55 oral, 53 intravaginal). Of the study population, 34% achieved therapeutic cure, and this was not different between treatment groups. BV-associated bacteria were significantly reduced in both groups, but few subjects regained colonization with protective lactobacilli. Among women who achieved therapeutic cure, the level of IL-1β dropped significantly (p < 0.001) and SLPI increased (p = 0.003). More women in the vaginal treatment group had undetectable sialidase after treatment (p = 0.013). Conclusions Treatment with oral or intravaginal metronidazole in early pregnancy reduced colonization with BV-associated bacteria but was not effective in achieving therapeutic cure or in restoring healthy vaginal lactobacilli. PMID:19951217

  5. Micromatricial metronidazole benzoate film as a local mucoadhesive delivery system for treatment of periodontal diseases.

    PubMed

    El-Kamel, Amal Hassan; Ashri, Lubna Y; Alsarra, Ibrahim A

    2007-09-14

    The main objective of this study was to develop a local, oral mucoadhesive metronidazole benzoate (MET) delivery system that can be applied and removed by the patient for the treatment of periodontal diseases. Mucoadhesive micromatricial chitosan/poly(epsilon-caprolactone) (CH/PCL) films and chitosan films were prepared. Thermal behavior, morphology, and particle size measurements were used to evaluate the prepared films. The effect of different molar masses of CH and different ratios of medium Mwt molar mass chitosan (MCH):PCL on water absorption, in vitro bioadhesion, mechanical properties, and in vitro drug release was examined. In vivo performance of the selected formulation was also evaluated. Differential scanning calorimetry examination revealed that MET existed mainly in amorphous form. Under microscopic examination, PCL microparticles were homogeneously dispersed in the films. The use of different molar masses of CH and different ratios of (MCH):PCL affected the size of the entrapped particles. Addition of PCL significantly decreased percentage water uptake and bioadhesion force compared with pure CH film. With regard to mechanical properties, the 2-layered film containing 1:0.625 MCH:PCL had the best tensile properties. At fixed CH:PCL ratio (1:1.25), the slowest drug release was obtained from films containing high molar mass CH. On the other hand, the 2-layered film that consisted of 1:0.625 MCH:PCL had the slowest MET release. In vivo evaluation of the selected film revealed that metronidazole concentration in saliva over 6 hours ranged from 5 to 15 microg/mL, which was within and higher than the reported range of minimum inhibitory concentration for metronidazole. A significant in vitro/in vivo correlation under the adopted experimental conditions was obtained.

  6. [Simultaneous determination of 6 antibiotics and metronidazole in acne removal products bt high performance liquid chromatography].

    PubMed

    Lu, Jun; Pang, Yanjun; Li, Yanbo; Wang, Chao

    2012-06-01

    An analytical method for the simultaneous determination of 6 antibiotics (minocycline, oxytetracycline, tetracycline hydrochloride, chlorotetracycline hydrochloride, doxycycline hydrochloride and chloramphenicol) and metronidazole in acne removal products of cosmetic was established using high performance liquid chromatography (HPLC). The drugs in the sample were extracted with methanol. The separation was performed on an Agilent ZORBAX SB-C18 column (250 mm x 4.6 mm, 5 microm) at 20 degrees C with methanol, acetonitrile and 0.002 mol/L oxalic acid solution as mobile phases with gradient elution at a flow rate of 0.8 mL/min. The detection was performed by a diode array detector (DAD) at 268 nm. The injection volume was 10 microL. The quantification was performed by external standard method. The calibration curves showed good linearity within the range of 1 - 30 mg/L with the correlation coefficients no less than 0.997 0. The detection limits were in the range of 1.1 - 1.2 microg/g. The recoveries were between 91.9% and 107.7% in three spiked levels of 5, 10 and 20 mg/L with the relative standard deviations (RSDs) of 0.13% - 1.74%. The method was used in the analysis of acne removal products, and metronidazole was found in 15% of the total test samples. The method is rapid, sensitive, accurate, effective in separation, and can be used in the determination of the six antibiotics and metronidazole in acne removal products.

  7. Microbiologic Response to Treatment of Bacterial Vaginosis with Topical Clindamycin or Metronidazole

    PubMed Central

    Austin, M. N.; Beigi, R. H.; Meyn, L. A.; Hillier, S. L.

    2005-01-01

    To compare the frequencies, concentrations, and antimicrobial susceptibilities of vaginal microbes isolated from women with bacterial vaginosis (BV) before and after therapy, 119 nonpregnant women aged 18 to 45 with clinical and Gram stain evidence of BV were randomized to receive intravaginal clindamycin or metronidazole. Vaginal swabs were collected at baseline and 7 to 12 days, 35 to 45 days, and 70 to 90 days following therapy for quantitative vaginal culture. For the 99 women completing all four visits, statistical analyses were performed comparing differences in vaginal microflora between the two treatment arms and between visits in the same treatment group. Antimicrobial susceptibility testing using the agar dilution method was performed for anaerobic gram-negative rods. Although both therapies resulted in decreased colonization by Gardnerella vaginalis and Mycoplasma hominis, only metronidazole treatment resulted in a significant decrease in the frequency and concentration of Prevotella bivia and black-pigmented Prevotella species. Of the 865 anaerobic gram-negative rods evaluated for susceptibility, only 3 (0.3%) were resistant to metronidazole, whereas clindamycin resistance increased significantly for P. bivia and black-pigmented anaerobic gram-negative rods persisting following clindamycin therapy. Clindamycin-resistant subpopulations of P. bivia and black-pigmented Prevotella species emerged 7 to 12 days after therapy even among women colonized initially by clindamycin-susceptible strains. These resistant subpopulations persisted at high frequencies (42 to 50%) 70 to 90 days following therapy. The two topical agents for treatment of BV have differing microbiologic effects on the vaginal microflora. The emergence of clindamycin-resistant anaerobic gram-negative rods following therapy is of concern. PMID:16145097

  8. Effect of Metronidazole in Infants with Bowel Habit Change: Irrelative to the Clostridium difficile Colonization.

    PubMed

    Kim, Eun Jin; Lee, Sung Hyun; Tchah, Hann; Ryoo, Eell

    2017-03-01

    Clinical symptoms associated with Clostridium difficile infection (CDI) can vary widely. Carrier state without apparent symptoms is relatively common during infancy. The objective of this study was to determine the association of C. difficile colonization with bowel habit change and the effect of C. difficile colonization treatment on restoration of normal bowel habit. Between 2006 and 2014, infants at 1 to 12 months of age with diarrhea for more than 2 weeks who did not improve with conservative care were recruited from Gachon University Gil Medical Center. Infants who were followed up for at least 7 days were included. The presence or absence of C. difficile colonization, effect of metronidazole, and other medical records were reviewed. To determine the association between CDI and bowel habit change, logistic regression analysis was used. Of a total of 126 infants, 74 (58.7%) were male patients. Of the 126 patients, 27 (21.4%) had C. difficile colonization. Significant (p<0.05) risk factors for C. difficile colonization included artificial milk feeding (odds ratio [OR], 4.310; 95% confidence interval [CI], 1.564-11.878), prior rotavirus vaccination (OR, 4.322; 95% CI, 1.018-18.349), and antibiotic use (OR, 4.798; 95% CI, 1.430-16.101). There was improvement in bowel habit after metronidazole therapy (OR, 0.34; 95% CI, 0.15-0.79; p<0.05), regardless of the presence or absence of C. difficile colonization. There was no significant correlation between bowel habit change and C. difficile colonization during infancy. However, metronidazole can be used as an optional method to manage functional gastrointestinal disorders.

  9. Microbiologic response to treatment of bacterial vaginosis with topical clindamycin or metronidazole.

    PubMed

    Austin, M N; Beigi, R H; Meyn, L A; Hillier, S L

    2005-09-01

    To compare the frequencies, concentrations, and antimicrobial susceptibilities of vaginal microbes isolated from women with bacterial vaginosis (BV) before and after therapy, 119 nonpregnant women aged 18 to 45 with clinical and Gram stain evidence of BV were randomized to receive intravaginal clindamycin or metronidazole. Vaginal swabs were collected at baseline and 7 to 12 days, 35 to 45 days, and 70 to 90 days following therapy for quantitative vaginal culture. For the 99 women completing all four visits, statistical analyses were performed comparing differences in vaginal microflora between the two treatment arms and between visits in the same treatment group. Antimicrobial susceptibility testing using the agar dilution method was performed for anaerobic gram-negative rods. Although both therapies resulted in decreased colonization by Gardnerella vaginalis and Mycoplasma hominis, only metronidazole treatment resulted in a significant decrease in the frequency and concentration of Prevotella bivia and black-pigmented Prevotella species. Of the 865 anaerobic gram-negative rods evaluated for susceptibility, only 3 (0.3%) were resistant to metronidazole, whereas clindamycin resistance increased significantly for P. bivia and black-pigmented anaerobic gram-negative rods persisting following clindamycin therapy. Clindamycin-resistant subpopulations of P. bivia and black-pigmented Prevotella species emerged 7 to 12 days after therapy even among women colonized initially by clindamycin-susceptible strains. These resistant subpopulations persisted at high frequencies (42 to 50%) 70 to 90 days following therapy. The two topical agents for treatment of BV have differing microbiologic effects on the vaginal microflora. The emergence of clindamycin-resistant anaerobic gram-negative rods following therapy is of concern.

  10. [Topical treatment of peri-implantitis with metronidazole dental gel 25%. Clinical analysis and microbiological control].

    PubMed

    Stellini, E; Migliorato, A; Mazzoleni, S; Mottola, A; Lombardi, L; Favero, G A

    2000-01-01

    Aim of this research is to verify the efficacy of metronidazole dental gel 25%, used as a topical antibiotic for the treatment of peri-implantitis. The efficacy of the medicine in the starting phase of the disease (mucositis), as well as during peri-implantitis involving bone-bearing loss has been evaluated. Twenty patients were chosen as a sample for the study. After careful evaluation of the several protocols concerning peri-implantitis treatment, some diagnostic clinical parameters have been recorded for each patient and metronidazole dental gel 25% (Elyzol Cabon) has been administered in two applications at perimplants pocket (one after a week). For each patient 3 microbiological drawings were made for the evaluation of the bacterial population around the implant site. From the microbiological examination a decrease of Gram- and an increase of Gram+ which returned in almost all the patients to normal levels have been observed; moreover, in all the patients a gradual decrease of PMN, resolution index of the inflammatory process was obtained, confirmed also by a remarkable improvement of all the observed diagnostic parameters, except for the peri-implants bone radiotransparency which was unchanged. The research showed that the peri-implant diseases can be positively resolved by using the metronidazole dental gel 25% topical antibiotic. This drug led to a 60-70% decrease of Gram-, and 40-50% increase for Gram+, bringing these back to normal values in almost all the patients. Moreover, a good recovery of the peri-implants soft tissues has been observed.

  11. Effect of Metronidazole in Infants with Bowel Habit Change: Irrelative to the Clostridium difficile Colonization

    PubMed Central

    Kim, Eun Jin; Lee, Sung Hyun; Tchah, Hann

    2017-01-01

    Purpose Clinical symptoms associated with Clostridium difficile infection (CDI) can vary widely. Carrier state without apparent symptoms is relatively common during infancy. The objective of this study was to determine the association of C. difficile colonization with bowel habit change and the effect of C. difficile colonization treatment on restoration of normal bowel habit. Methods Between 2006 and 2014, infants at 1 to 12 months of age with diarrhea for more than 2 weeks who did not improve with conservative care were recruited from Gachon University Gil Medical Center. Infants who were followed up for at least 7 days were included. The presence or absence of C. difficile colonization, effect of metronidazole, and other medical records were reviewed. To determine the association between CDI and bowel habit change, logistic regression analysis was used. Results Of a total of 126 infants, 74 (58.7%) were male patients. Of the 126 patients, 27 (21.4%) had C. difficile colonization. Significant (p<0.05) risk factors for C. difficile colonization included artificial milk feeding (odds ratio [OR], 4.310; 95% confidence interval [CI], 1.564-11.878), prior rotavirus vaccination (OR, 4.322; 95% CI, 1.018-18.349), and antibiotic use (OR, 4.798; 95% CI, 1.430-16.101). There was improvement in bowel habit after metronidazole therapy (OR, 0.34; 95% CI, 0.15-0.79; p<0.05), regardless of the presence or absence of C. difficile colonization. Conclusion There was no significant correlation between bowel habit change and C. difficile colonization during infancy. However, metronidazole can be used as an optional method to manage functional gastrointestinal disorders. PMID:28401056

  12. EVALUATION OF THE MUTAGENIC ACTIVITY OF 3-NBA (3-NITROABENZANTHRONE) USING STRAINS OF SALMONELLA TYPHIMURIUM WITH DIFFERENT LEVELS OF THE ENZYMES NITROREDUCTASE AND ACETYLTRANSFERASE

    EPA Science Inventory

    The 3-NBA (3-nitro-7H- benz[d,e]antracen-7-one) is extremely potent in the Ames test an useful test for mutagenicity, being a possible inducer of tumors in animals and possible carcinogen for human beings. 3-NBA was previously identified in the exhausts of diesel, particulate mat...

  13. EVALUATION OF THE MUTAGENIC ACTIVITY OF 3-NBA (3-NITROABENZANTHRONE) USING STRAINS OF SALMONELLA TYPHIMURIUM WITH DIFFERENT LEVELS OF THE ENZYMES NITROREDUCTASE AND ACETYLTRANSFERASE

    EPA Science Inventory

    The 3-NBA (3-nitro-7H- benz[d,e]antracen-7-one) is extremely potent in the Ames test an useful test for mutagenicity, being a possible inducer of tumors in animals and possible carcinogen for human beings. 3-NBA was previously identified in the exhausts of diesel, particulate mat...

  14. In situ forming implants for the delivery of metronidazole to periodontal pockets: formulation and drug release studies.

    PubMed

    Kilicarslan, Muge; Koerber, Martin; Bodmeier, Roland

    2014-05-01

    This study was performed to obtain prolonged drug release with biodegradable in situ forming implants for the local delivery of metronidazole to periodontal pockets. The effect of polymer type (capped and uncapped PLGA), solvent type (water-miscible and water-immiscible) and the polymer/drug ratio on in vitro drug release studies were investigated. In situ implants with sustained metronidazole release and low initial burst consisted of capped PLGA and N-methyl-2-pyrolidone as solvent. Mucoadhesive polymers were incorporated into the in situ implants in order to modify the properties of the delivery systems towards longer residence times in vivo. Addition of the polymers changed the adhesiveness and increased the viscosity and drug release of the formulations. However, sustained drug release over 10 days was achievable. Biodegradable in situ forming implants are therefore an attractive delivery system to achieve prolonged release of metronidazole at periodontal therapy.

  15. [The effect of selected hydrophilisers on metronidazole release from hydrogels stomatological dressings on the basis of Carbopol 971].

    PubMed

    Kida, Dorota; Pluta, Janusz

    2010-01-01

    The aim of this study was to assess the influence of qualitative and quantitative base composition on pharmaceutical availability of metronidazole. Hydrogels contain water dispersion of 2% Carbopol 971P and various concentration of glycerol, polyethylene glycol and propylene glycol were preparated. Produced formulations were neutralized to the pH 6.0-6.5 with triethanolamine, and metronidazole in concentration 1% added. The test for pharmaceutical bioavailability was performed in vitro, the rate of diffusing therapeutic agent through a semipermable into acceptor fluid was tested. The quantity of metronidazole released at the same time intervals was tested by spectrophotometric method. Hydrogel consists of 99% water dispersion of Carbopol 971P and 1% glycerol characterized by the largest pharmaceutical bioavailability.

  16. Comparative antimicrobial efficacy of Metapex, Metronidazole, BioPure MTAD, Aztreonam on Bacteroides fragilis and Propionibacterium acne

    PubMed Central

    Balakrishnan, Rajkumar; Dubey, Sandeep; Dhole, Tapan Kumar N; Boruah, Lalit C; Srivastava, Sanjeev

    2013-01-01

    Aim: The purpose of this study was to evaluate the comparative antibacterial efficacy of Biopure MTAD, Metapex, Metronidazole, and Aztreonam against two obligate anerobic bacteria. Materials and Methods: Antimicrobial efficacy of selected medicaments against two obligate anaerobic bacteria Bacteroides fragilis and Propionibacterium acnes was done by Agar disc-diffusion method. Pre-sterilized Whatman paper discs, 6 mm in diameter and soaked with the test solution, were prepared and placed onto the previously seeded agar Petri plates. Each plate was incubated in anaerobic jar for anerobic environment at 37°C for 48 hours. A zone of inhibition was recorded for each plate and the results were analysed statistically. Saline and ethanol used as control group in this study. Results: Biopure MTAD, Metapex and Metronidazole were effective against all the selected microorganisms. Aztreonam was effective against Bacteroides fragilis. Saline and ethanol used as control were ineffective. Conclusions: Metronidazole showed the superior antibacterial property amongst the tested medicaments. PMID:23956535

  17. Pharmacokinetics of metronidazole in foals: influence of age within the neonatal period.

    PubMed

    Swain, E A; Magdesian, K G; Kass, P H; Edman, J E; Knych, H K

    2015-06-01

    Neonatal foals have unique pharmacokinetics, which may lead to accumulation of certain drugs when adult horse dosage regimens are used. Given its lipophilic nature and requirement for hepatic metabolism, metronidazole may be one of these drugs. The purpose of this study was to determine the pharmacokinetic profiles of metronidazole in twelve healthy foals at 1-2.5 days of age when administered as a single intravenous (IV) and intragastric (IG) dose of 15 mg/kg. Foals in the intravenous group were studied a second time at 10-12 days of age to evaluate the influence of age on pharmacokinetics within the neonatal period. Blood samples were collected at serial time points after metronidazole administration. Metronidazole concentration in plasma was measured using LC-MS. Pharmacokinetic parameters were determined using noncompartmental analysis and compared between age groups. At 1-2.5 days of age, the mean peak plasma concentration after IV infusion was 18.79 ± 1.46 μg/mL, elimination half-life was 11.8 ± 1.77 h, clearance was 0.84 ± 0.13 mL/min/kg and the volume of distribution (steady-state) was 0.87 ± 0.07 L/kg. At 10-12 days of age, the mean peak plasma concentration after IV infusion was 18.17 ± 1.42 μg/mL, elimination half-life was 9.07 ± 2.84 h, clearance was 1.14 ± 0.21 mL/min/kg and the volume of distribution (steady-state) was 0.88 ± 0.06 L/kg. Oral approximated bioavailability was 100%. Cmax and Tmax after oral dosing were 14.85 ± 0.54 μg/mL and 1.75 (1-4) h, respectively. The elimination half-life was longer and clearance was reduced in neonatal foals at 1-2.5 days as compared to 10-12 days of age (P = 0.006, P = 0.001, respectively). This study warrants consideration for altered dosing recommendations in foals, especially a longer interval (12 h). © 2014 John Wiley & Sons Ltd.

  18. Population Pharmacokinetics of Metronidazole Evaluated Using Scavenged Samples from Preterm Infants

    PubMed Central

    Ouellet, Daniele; Smith, P. Brian; James, Laura P.; Ross, Ashley; Sullivan, Janice E.; Walsh, Michele C.; Zadell, Arlene; Newman, Nancy; White, Nicole R.; Kashuba, Angela D. M.; Benjamin, Daniel K.

    2012-01-01

    Pharmacokinetic (PK) studies in preterm infants are rarely conducted due to the research challenges posed by this population. To overcome these challenges, minimal-risk methods such as scavenged sampling can be used to evaluate the PK of commonly used drugs in this population. We evaluated the population PK of metronidazole using targeted sparse sampling and scavenged samples from infants that were ≤32 weeks of gestational age at birth and <120 postnatal days. A 5-center study was performed. A population PK model using nonlinear mixed-effect modeling (NONMEM) was developed. Covariate effects were evaluated based on estimated precision and clinical significance. Using the individual Bayesian PK estimates from the final population PK model and the dosing regimen used for each subject, the proportion of subjects achieving the therapeutic target of trough concentrations >8 mg/liter was calculated. Monte Carlo simulations were performed to evaluate the adequacy of different dosing recommendations per gestational age group. Thirty-two preterm infants were enrolled: the median (range) gestational age at birth was 27 (22 to 32) weeks, postnatal age was 41 (0 to 97) days, postmenstrual age (PMA) was 32 (24 to 43) weeks, and weight was 1,495 (678 to 3,850) g. The final PK data set contained 116 samples; 104/116 (90%) were scavenged from discarded clinical specimens. Metronidazole population PK was best described by a 1-compartment model. The population mean clearance (CL; liter/h) was determined as 0.0397 × (weight/1.5) × (PMA/32)2.49 using a volume of distribution (V) (liter) of 1.07 × (weight/1.5). The relative standard errors around parameter estimates ranged between 11% and 30%. On average, metronidazole concentrations in scavenged samples were 30% lower than those measured in scheduled blood draws. The majority of infants (>70%) met predefined pharmacodynamic efficacy targets. A new, simplified, postmenstrual-age-based dosing regimen is recommended for this

  19. Isolation of Clostridium difficile from dogs with digestive disorders, including stable metronidazole-resistant strains.

    PubMed

    Orden, Cristina; Blanco, Jose L; Álvarez-Pérez, Sergio; Garcia-Sancho, Mercedes; Rodriguez-Franco, Fernando; Sainz, Angel; Villaescusa, Alejandra; Harmanus, Celine; Kuijper, Ed; Garcia, Marta E

    2017-02-01

    The prevalence of Clostridium difficile in 107 dogs with diverse digestive disorders attended in a Spanish veterinary teaching hospital was assessed. The microorganism was isolated from 13 dogs (12.1%) of different disease groups. Isolates belonged to PCR ribotypes 078, 106, 154 and 430 (all of them toxigenic) and 110 (non-toxigenic), and were resistant to several antimicrobial drugs. Notably, seven isolates obtained from different dogs displayed stable resistance to metronidazole. The results of this study provide further evidence that dogs can act as a reservoir of C. difficile strains of epidemic ribotypes with resistance to multiple antibiotics.

  20. Therapy for Clostridium difficile infection - any news beyond Metronidazole and Vancomycin?

    PubMed

    Manthey, C F; Eckmann, L; Fuhrmann, V

    2017-08-11

    Infections with Clostridium difficile (CDI) represent a major burden for the health care system. Treatment is generally by antibiotic therapy with metronidazole and vancomycin, but efficacy remains suboptimal. Areas covered: This review discusses established and emerging treatment options for CDI, and current therapeutic guidelines, taking into account disease severity and risk of relapse. Expert commentary: New therapeutic approaches, including antibodies and new classes of antibiotics, and new measures for preventing infection with vaccines are under development in phase II/III clinical trials. We performed a systematic literature review using the search terms 'Clostridium difficile' and 'treatment'.

  1. Clinical efficacy of Saccharomyces boulardii or metronidazole in symptomatic children with Blastocystis hominis infection.

    PubMed

    Dinleyici, Ener Cagri; Eren, Makbule; Dogan, Nihal; Reyhanioglu, Serap; Yargic, Zeynel Abidin; Vandenplas, Yvan

    2011-03-01

    Although many Blastocystis infections remain asymptomatic, recent data suggest it also causes frequent symptoms. Therapy should be limited to patients with persistent symptoms and a complete workup for alternative etiologies. The goal of this study was to compare the natural evolution (no treatment) to the efficacy of Saccharomyces boulardii (S. boulardii) or metronidazole for the duration of diarrhea and the duration of colonization in children with gastrointestinal symptoms and positive stool examination for Blastocystis hominis. This randomized single-blinded clinical trial included children presenting with gastrointestinal symptoms (abdominal pain, diarrhea, nausea-vomiting, flatulence) more than 2 weeks and confirmed B. hominis by stool examination (B. hominis cysts in the stool with microscopic examination of the fresh stool). The primary end points were clinical evaluation and result of microscopic stool examination at day 15. Secondary end points were the same end points at day 30. Randomization was performed by alternating inclusion: group A, S. boulardii (250 mg twice a day, Reflor®) during 10 days; group B, metronidazole (30 mg/kg twice daily) for 10 days; group C, no treatment. At day 15 and 30 after inclusion, the patients were re-evaluated, and stool samples were examined microscopically. On day 15, children that were still symptomatic and/or were still B. hominis-infected in group C were treated with metronidazole for 10 days. There was no statistically significant difference between the three study groups for age, gender, and the presence of diarrhea and abdominal pain. On day 15, clinical cure was observed in 77.7% in group A (n, 18); in 66.6% in group B (n, 15); and 40% in group C (n:15) (p < 0.031, between groups A and C). Disappearance of the cysts from the stools on day 15 was 80% in group B, 72.2% in group A, and 26.6% in group C (p = 0.011, between group B and group C; p = 0.013, between group A and group C). At the end of the first month

  2. [Pneumatosis Coli Treated with Metronidazole and Hyperbaric Oxygen Therapy: A Successful Case].

    PubMed

    Costa, Mariana; Morgado, Carolina; Andrade, David; Guerreiro, Francisco; Coimbra, João

    2015-01-01

    Pneumatosis intestinalis, characterized by the presence of gas within the bowel wall, is an uncommon condition with variable presentation. It may be idiopathic or secondary to other diseases. A computed tomography scan is the most sensitive method for diagnosis. In the absence of signs and symptoms of complications, such as perforation and peritonitis, pneumatosis intestinalis can be managed conservatively. We present the case of a 59-year-old woman with pneumatosis coli secondary to benign ovary teratoma. After surgery she remained symptomatic and was successfully treated with metronidazole and hyperbaric oxygen therapy.

  3. Use of metronidazole as part of an empirical antibiotic regimen after incision and drainage of infections of the odontogenic spaces.

    PubMed

    Bali, Rishi; Sharma, Parveen; Gaba, Shivani

    2015-01-01

    The combination of amoxicillin/clavulanate and metronidazole is a widely-accepted empirical regimen for infections of the odontogenic spaces. Once adequate drainage has been established micro-organisms are less likely to grow and multiply, particularly anaerobes. This may obviate the need for anaerobic coverage after drainage in healthy hosts. We studied 60 patients in this randomised prospective study, the objective of which was to evaluate metronidazole as part of an empirical antibiotic regimen after drainage of infections of the odontogenic spaces. Samples of pus were sent for culture and testing for sensitivity. Amoxicillin/clavulanate and metronidazole were given to all patients. After incision and drainage the patients were randomly allocated to two groups. In the first group both antibiotics were continued, and in the second metronidazole was withdrawn. The groups were compared both clinically and microbiologically. There were no significant differences between the groups in the resolution of infection. Thirteen patients (n=6 in the 2-antimicrobial group, and n=7 in the amoxicillin/clavulanate group) showed no improvement during the 48 h postoperatively. Overall there was need to substitute another antibiotic for amoxicillin/clavulanate in only 6 cases. Six patients in the amoxicillin/clavulanate group required the addition of metronidazole after drainage. We conclude that in healthy subjects metronidazole is not necessary in the period after drainage, but its prescription should be based on assessment of clinical and laboratory markers of infection. Copyright © 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  4. Risk of Clostridium difficile infection in hospitalized patients receiving metronidazole for a non-C difficile infection.

    PubMed

    Rodriguez, Sandra; Hernandez, Marlow B; Tarchini, Giorgio; Zaleski, Megan; Vatanchi, Marjon; Cardona, Lyssette; Castro-Pavia, Fernando; Schneider, Alison

    2014-11-01

    Antibiotics often are given to prevent infections but also constitute a risk factor for Clostridium difficile infection (CDI). Metronidazole is an effective treatment for CDI. We investigated whether prophylactic administration of metronidazole to patients before they receive other antibiotics reduces the risk of CDI. We performed a retrospective cohort analysis of data collected from 12,026 high-risk patients admitted to Cleveland Clinic Foundation Hospitals from 2008 through 2012. High-risk patients were defined as age 55 or older who received a broad-spectrum antibiotic (piperacillin-tazobactam or ciprofloxacin) and a gastric acid suppressant (a proton pump inhibitor or a histamine-2 receptor blocker) during their hospitalization. Development of CDI was compared between patients who received metronidazole for non-CDI indications before broad-spectrum antibiotics (n = 811) and those who did not (n = 11,215). Logistic regression was used to control for patient demographics and comorbidities. The rate of CDI was 1.4% (n = 11) among the patients who received metronidazole for non-CDI indications and 6.5% (n = 728) among those who did not. This was observed to be an 80% reduction in CDI among patients who received metronidazole (odds ratio, 0.21; 95% confidence interval, 0.11-0.38; P < .001), adjusted for age, sex, and comorbidities. Based on a retrospective analysis, metronidazole might be used to prevent CDI in certain high-risk patients. Prospective controlled trials are necessary before making further recommendations. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

  5. A comparative study of the therapeutic effects of the Zataria multiflora vaginal cream and metronidazole vaginal gel on bacterial vaginosis.

    PubMed

    Simbar, M; Azarbad, Z; Mojab, F; Majd, H Alavi

    2008-12-01

    Bacterial vaginosis (BV) is one of most prevalent complications among reproductive-aged women. Metromidazole prescription, which is considered as the first-line treatment of BV, is usually followed by a few side effects. Besides, there is a growing tendency toward herbal medicines for the treatment of vaginitis. Antibacterial and antifungal effects of Zataria multiflora (Z. multiflora) have been demonstrated in vitro and in vivo. This study aimed to compare the therapeutic effects of the Z. multiflora vaginal cream and metronidazole vaginal gel on bacterial vaginosis. This was a randomized clinical trial on 90 married women aged 18-40 affected by BV who attended for treatment to the gynecology clinic of Shabih-Khani Hospital. They randomly divided to two groups of 45 participants. Diagnostic criteria were Amsel's criteria and Gram stain. Z. multiflora vaginal cream or metronidazole vaginal gel for five-night usage were prescribed to each group, and after 2-7 days therapeutic effects on participants' complications and their Amsel criteria were assessed. Data analysis was performed by McNemar and Fisher exact tests. Patients' complication and their Amsel's criteria were significantly decreased after treatment with Z. multiflora or metronidazole (p<0.05). Relative risk for unresponsiveness to treatment with Z. multiflora, to unresponsiveness to metronidazole was 1.5, which was not significant. Therapeutic effects of Z. multiflora vaginal cream are similar to metronidazole vaginal gel on BV. Therefore it could be an appropriate choice to BV treatment for those interested in herbal medicines or those affected by side effects of metronidazole.

  6. Standardization of disk diffusion test and its clinical significance for susceptibility testing of metronidazole against Helicobacter pylori.

    PubMed Central

    Xia, H; Keane, C T; Beattie, S; O'Morain, C A

    1994-01-01

    Susceptibilities of 121 clinical Helicobacter pylori strains to metronidazole were determined by both a 5-micrograms metronidazole disk diffusion test and a plate dilution method in duplicate and after different periods of incubation. The distribution of MICs of metronidazole against H. pylori among the strains was found to be bimodal. The diameters of inhibitory zones obtained by the disk diffusion test and the MICs obtained by the plate dilution method correlated well, especially after 4 days of incubation (r = 0.77). An inhibitory zone diameter of 20 mm was found to correspond to a MIC of 8 micrograms/ml and is recommended as a suitable zone for differentiating susceptibility and resistance with a 5-micrograms metronidazole disk. Three interpretive categories of susceptibility results were defined; strains with inhibitory zone diameters of more than 26 mm were defined as susceptible (MIC, < 4 micrograms/ml), strains with zone diameters of 20 to 26 mm were deemed intermediate (MIC, 4 to 8 micrograms/ml), and those with zone diameters of less than 20 mm were deemed resistant (MIC, > 8 micrograms/ml). Furthermore, 76 H. pylori-positive patients with duodenal ulcers or nonulcer dyspepsia were treated with a 1 week of triple therapy (colloidal bismuth subcitrate, metronidazole, and tetracycline). H. pylori strains were isolated before treatment from antral biopsies from those patients, and the metronidazole susceptibilities of the strains were determined by the disk diffusion test. H. pylori status was evaluated again 4 weeks after completion of treatment. The eradication rates for susceptible, intermediate, and resistant strains were 95.9% (47 of 49), 62.5% (5 of 8), and 52.6% (10 of 19), respectively. It is included that the 5-micrograms disk diffusion test is easy to perform and gives final results similar to those of the plate dilution method. The three interpretive categories of susceptibility may be of benefit for clinical choice of chemotherapy in eradicating

  7. Preparation and evaluation of gastroretentive floating pellets of metronidazole using Na-alginate and hydroxyl propyl methyl cellulose polymers.

    PubMed

    Biswas, S K; Paul, S; Chowdhury, A; Das, J

    2012-03-15

    Gastroretentive floating pellets of metronidazole were formulated to prolong the gastric residence time in order to obtain controlled release characteristics of the drug. Nine formulations of metronidazole floating pellets such as AX, BX, CX, AY, BY, CY, AZ, BZ and CZ were prepared by extrusion method using different quantities of hydroxyl propyl methyl cellulose (HPMC) polymers such as methocel K4M premium and methocel K100LV premium in the ratio of 2:1, 1:2 and 1.5:1.5 while the amount of Na-alginate used in the formulations was 3.50, 5.25 and 7.0 g, respectively. The in vitro dissolution studies were carried out in 900 mL of phosphate buffer (pH 1.2) at 37 +/- 0.5 degrees C and 50 rpm for 6 h using USP XXIV paddle method and the content of drug release was done by UV spectrophotometer at 277 nm. It was found that the percent release of metronidazole from different formulations was different with passing of time. The drug release profile of the formulation (AX) having Na-alginate 3.50 g methocel K4M premium and methocel K100LV premium in the ratio of 2:1 showed best fit to Higuchi release kinetics with R2 value of 0.994. Finally, it might be concluded that the polymers had significant effect on drug release kinetics of metronidazole from floating pellets. The selection and use of suitable polymers in appropriate ratio might be very important in designing floating pellets and using the capabilities of these polymers, suitable floating pellets of metronidazole with desirable release rate could be formulated. Thus, in vivo research studies by the future researchers will confirm the appropriateness of these formulated metronidazole floating pellets.

  8. A Meta-analysis of the Effectiveness of Albendazole Compared with Metronidazole as Treatments for Infections with Giardia duodenalis

    PubMed Central

    Solaymani-Mohammadi, Shahram; Genkinger, Jeanine M.; Loffredo, Christopher A.; Singer, Steven M.

    2010-01-01

    Background Metronidazole is the most commonly used drug for the treatment of giardiasis in humans. In spite of its therapeutic efficacy for giardiasis, low patient compliance, especially in children, side effects, and the emergence of metronidazole-resistant strains may restrict its use. Albendazole has been used to treat Giardia duodenalis infections in recent years. However, efficacy studies in vivo and in vitro have produced diverse results as to its effectiveness. A moderately benign side effect profile, combined with established efficacy against many helminths, renders it promising for treatment of giardiasis in humans. Methodology and Principal Findings We performed a search in the PubMed, Scopus, EMBASE, the ISI Web of Science, LILIACS, and Cochrane Controlled Trials Register for trials published before February 2010 as well as in references of relevant research and review articles. Eight randomized clinical trials (including 900 patients) comparing the effectiveness of albendazole with that of metronidazole were included in meta-analysis. After extracting and validating the data, the pooled risk ratio (RR) was calculated using an inverse-variance random-effects model. Albendazole was found to be equally as effective as metronidazole in the treatment of giardiasis in humans (RR 0.97; 95% CI, 0.93, 1.01). In addition, safety analysis suggested that patients treated with albendazole had a lower risk of adverse effects compared with those who received metronidazole (RR 0.36; 95% CI, 0.10, 1.34), but limitations of the sample size precluded a definite conclusion. Conclusions/Significance The effectiveness of albendazole, when given as a single dose of 400 mg/day for 5 days, was comparable to that of metronidazole. Patients treated with albendazole tended to have fewer side effects compared with those who took metronidazole. Given the safety, effectiveness, and low costs of albendazole, this drug could be potentially used as an alternative and/or a replacement

  9. Effect of metronidazole supplemented with hydroquinone on the adhesion of Lactobacillus acidophilus in ovine vaginal cells.

    PubMed

    Coletti Zabala, Tamara L; Zerbatto, María E; Perotti, Elda B R; Smacchia, Ana M; Ombrella, Adriana; Pidello, Alejandro R

    This work demonstrates that the addition of metronidazole together with a ubiquitous quinone compound reduces adherence of Lactobacillus acidophilus to ovine vaginal cells. Spectrophotometric and voltammetric studies have shown that neoformed compounds were observed in these systems; there were also changes in their electroactive composition, and the oxidant status had a significantly higher value compared to the control (p<0.05). Based on reduction potential (E; mV), the distribution of electroactive compound concentrations suggests that the compounds with low reduction potential induce this behavior, which would indicate that the addition of metronidazole with a ubiquitous quinone compound to the vaginal system might increase the reductive capacity of these systems. This work shows that the study of behavior and fluctuations of the redox compounds that compose the vaginal environment, in terms of concentration and species of redox molecules, must be hierarchized in order to better understand the early stages of colonization by microorganisms. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. Pectosomes and Chitosomes as Delivery Systems for Metronidazole: The One-Pot Preparation Method

    PubMed Central

    Andersen, Toril; Vanić, Željka; Flaten, Gøril Eide; Mattsson, Sofia; Tho, Ingunn; Škalko-Basnet, Nataša

    2013-01-01

    Mucoadhesive liposomes offer a potential for improved residence time of liposomal systems targeting contact with mucosal tissues, such as in buccal, oral, colon, and vaginal drug delivery. Most of the currently available methods rely on the coating of preformed liposomes by various mucoadhesive polymers. The aim of this study was to develop novel mucoadhesive system by the one-pot preparation method. The pectin- and chitosan-containing liposomes, namely pectosomes and chitosomes, were prepared by the modified solvent injection method. In order to optimize this novel delivery system, we used pectins and chitosans of both high and low degree of esterification/deacetylation (DE/DD), respectively. Sonication was applied to reduce the original vesicle size. All vesicles were characterized for their size, zeta potential, metronidazole entrapment, and stability. Both pectosomes and chitosomes were found to entrap more metronidazole than conventional plain liposomes. Preliminary data indicate that the polymer is present on the liposomal surface, embedded within inner liposomal bilayers, and entrapped inside the aqueous compartment. The next step in the evaluation of this system is the testing of its mucoadhesiveness. PMID:24300517

  11. Metronidazole- and carbapenem-resistant bacteroides thetaiotaomicron isolated in Rochester, Minnesota, in 2014.

    PubMed

    Sadarangani, Sapna P; Cunningham, Scott A; Jeraldo, Patricio R; Wilson, John W; Khare, Reeti; Patel, Robin

    2015-07-01

    Emerging antimicrobial resistance in members of the Bacteroides fragilis group is a concern in clinical medicine. Although metronidazole and carbapenem resistance have been reported in Bacteroides thetaiotaomicron, a member of the B. fragilis group, they have not, to the best of our knowledge, been reported together in the same B. thetaiotaomicron isolate. Herein, we report isolation of piperacillin-tazobactam-, metronidazole-, clindamycin-, ertapenem-, and meropenem-resistant B. thetaiotaomicron from a patient with postoperative intra-abdominal abscess and empyema. Whole-genome sequencing demonstrated the presence of nimD with at least a portion of IS1169 upstream, a second putative nim gene, two β-lactamase genes (one of which has not been previously reported), two tetX genes, tetQ, ermF, two cat genes, and a number of efflux pumps. This report highlights emerging antimicrobial resistance in B. thetaiotaomicron and the importance of identification and antimicrobial susceptibility testing of selected anaerobic bacteria. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  12. Electrospraying technique for the fabrication of metronidazole contained PLGA particles and their release profile.

    PubMed

    Prabhakaran, Molamma P; Zamani, Maedeh; Felice, Betiana; Ramakrishna, Seeram

    2015-11-01

    Advanced engineering of materials for the development of drug delivery devices provides scope for novel and versatile strategies for treatment of various diseases. 'Electrospraying' was used to prepare PLGA microparticles and further encapsulate the drug, metronidazole (Met) within the particles to function as a drug delivery system. Two different solvents were utilized for the preparation of drug loaded PLGA particles, whereby the polymeric solution in dichloromethane (DCM) produced particles of bigger sizes than using trifluoroethanol (TFE). Scanning electron microscopy showed the spherical morphology of the particles, with sizes of 3946±407nm and 1774±167nm, respectively for PLGA-Met(DCM) and PLGA-Met(TFE). The FTIR spectroscopy proved the incorporation of metronidazole in the polymer, but without any specific drug-polymer interaction. The release of the drug from the particles was studied in phosphate buffered saline, where a sustained drug release was obtained for at least 41days. Cytotoxicity evaluation of the drug extract using mesenchymal stem cells (MSCs) showed not hindering the proliferation of MSCs, and the cell phenotype was retained after incubation in the drug containing media. Electrospraying is suggested as a cost-effective and single step process for the preparation of polymeric microparticles for prolonged and controlled release of drug. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Preparation and evaluation of novel metronidazole sustained release and floating matrix tablets.

    PubMed

    Asnaashari, Solmaz; Khoei, Nazaninossadat Seyed; Zarrintan, Mohammad Hosein; Adibkia, Khosro; Javadzadeh, Yousef

    2011-08-01

    In the present study, metronidazole was used for preparing floating dosage forms that are designed to retain in the stomach for a long time and have developed as a drug delivery system for better eradication of Helicobacter Pylori in peptic ulcer diseases. For this means, various formulations were designed using multi-factorial design. HPMC, psyllium and carbopol in different concentrations were used as floating agents, and sodium bicarbonate was added as a gas-forming agent. Hardness, friability, drug loading, floating ability and release profiles as well as kinetics of release were assessed. Formulations containing HPMC as filler showed prolonged lag times for buoyancy. Adding psyllium to these formulations had reduced relative lag times. Overall, selected formulations were able to float immediately and showed buoyancy for at least 8?h. Meanwhile, sustained profiles of drug release were also obtained. Kinetically, among the 10 assessed models, the release pattern of metronidazole from the tablets fitted best to Power law, Weibull and Higuchi models in respect overall to mean percentage error values of 3.8, 4.73 and 5.77, respectively, for calcium carbonate-based tablets and, 2.95, 6.39 and 3.9, respectively, for calcium silicate-based tablets. In general, these systems can float in the gastric condition and control the drug release from the tablets.

  14. The role of several l-HPCs in preventing tablet capping during direct compression of metronidazole.

    PubMed

    Martino, Piera Di; Malaj, Ledjan; Censi, Roberta; Martelli, Sante; Joiris, Etienne; Barthélémy, Christine

    2007-12-01

    Several low-hydroxypropyl cellulose (l-HPC) derivatives (LH-11, 21, 22, 31, and 32) differing in granulometric particle size or in hydroxypropyl content were considered in the present study. The l-HPC grades were characterized as pure powders, in order to determine both compression and densification behavior, in presence or in absence of magnesium stearate as lubricant, and then, were physically mixed in different proportions with metronidazole, which was also previously characterized as pure powder. The tabletability and compressibility of these binary mixtures were then evaluated, in presence or in absence magnesium stearate as lubricant at two different compression speeds (20 and 70 mm/sec). It was observed that both binary mixture compression behavior and capping tendency were influenced by compression speed and by the presence of lubricant. Differences in anti-capping efficiency between the l-HPCs may be related to their hydroxypropyl content. This parameter influences the interaction between the metronidazole and the polymer particles, and consequently the ability of the binary system to undergo densification under compression.

  15. Metronidazole loaded carboxymethyl tamarind kernel polysaccharide-polyvinyl alcohol cryogels: preparation and characterization.

    PubMed

    Meenakshi; Ahuja, Munish

    2015-01-01

    The purpose of present study was to prepare composite hydrogels of carboxymethyl tamarind kernel polysaccharide and polyvinyl alcohol employing freeze thaw-treatment and evaluate them for release behavior. The effect of concentrations of carboxymethyl tamarind kernel polysaccharide, polyvinyl alcohol, and freeze-thaw cycles on the % release of metronidazole was studied employing central composite experimental design. The result of the study revealed that the concentration of carboxymethyl tamarind kernel polysaccharide and interaction effect of concentrations of carboxymethyl tamarind kernel polysaccharide and polyvinyl alcohol influenced the release of metronidazole significantly. The optimal calculated parameters were concentration of carboxymethyl tamarind kernel polysaccharide-6.0% (w/v), concentration of polyvinyl alcohol-8.53% (w/v) and freeze-thaw cycles-4, which provided cryogels with a release of 75.77% over a period of 6h. The formation of cryogels was confirmed by Fourier-transformed infrared spectroscopy and X-ray diffraction studies. Thermal studies revealed higher thermal stability of cryogel.

  16. Clinical evaluation of an ointment with 10% metronidazole and 2% lidocaine in the treatment of alveolitis.

    PubMed

    Silva, L J; Poi, W R; Panzarini, S R; Rodrigues, T S; Simonato, L E

    2006-01-01

    In this study, the authors evaluate the use of a 10% metronidazole and 2% lidocaine ointment, using a lanolin base and mint as flavoring, to treat alveolitis in humans. Twenty-five patients, with a diagnosis of alveolitis, were treated in the following way: locoregional anesthesia; surgical cleaning of the socket with alveolar curettes; saline solution irrigation with a 20 ml disposable syringe; and complete filling of the socket with the ointment. The analysis of the results showed that the painful symptoms were severe before and on the day of the treatment in 17 (68%) of the 25 patients treated. Post-treatment analysis presented 2 patients (18%) with severe painful symptoms after 24 h of the treatment and complete remission of painful symptoms after 48 h of the treatment with the ointment. Based on the results, it is possible to conclude that the 10% metronidazole and 2% lidocaine ointment, with mint flavoring and lanolin as a base, can be used to treat alveolitis.

  17. Effect of serum albumin presence on the binding constant of metronidazole to the phospholipid membranes fluorescence study

    NASA Astrophysics Data System (ADS)

    Sułkowska, A.

    1999-05-01

    The experiment was designed to test the possibility of entrapping the drug metronidazole into liposome vesicles in order to use liposome vesicles as a drug carrier. We estimated the effect of size of the liposome and the presence of serum albumin on the leakage of the drug. Some interactions between the lipid membrane surface and serum albumin were demonstrated. As the effects of lipid composition and physical states in membranes on protein adsorption and binding are poorly understood, it is difficult to estimate the protein interaction with the lipid membrane surface. The fluorescence quenching technique was used in this investigation. The fluorescence of serum albumin tryptophanyl residues is reduced by the presence of metronidazole. When incorporated into liposomes, metronidazole reduces the fluorescence of tryptophanyl residues of BSA to a lesser extent. The least effect of metronidazole on the fluorescence of albumin is shown when the drug is incorporated into large liposomes (450 nm). Larger liposomes are less susceptible to the presence of serum albumin than the smaller ones. Large size of the liposomes is necessary to retain their stability in plasma.

  18. A randomized trial of metronidazole in asymptomatic bacterial vaginosis to prevent the acquisition of sexually transmitted diseases.

    PubMed

    Schwebke, Jane R; Desmond, Renee

    2007-06-01

    The purpose of this study was to determine whether treatment of bacterial vaginosis (BV) decreases the incidence of sexually transmitted diseases (STDs). Women with asymptomatic BV were studied prospectively to determine the effect of treatment of BV for the prevention of STD. Women were assigned randomly to observation or treatment and prophylaxis with intravaginal metronidazole gel. Women were screened monthly for STDs. Women who were assigned randomly to receive metronidazole gel had a significantly longer time to the development of STDs compared with women in the observation group (P = .02). The 6-month STD rate was 1.58 per person-year (95% CI, 1.29, 1.87) for women in the metronidazole gel group vs 2.29 per person-year (95% CI, 1.95, 2.63) for women in the observational group. The difference in STD rates was driven by a significant difference in the number of chlamydial infections (P = .013). Treatment and twice-weekly prophylactic use of intravaginal metronidazole gel resulted in significantly fewer cases of chlamydia.

  19. [The effect of the composition of stomatological dressings on Carbopol 971P and methylocelullose base on pharmaceutical availability of metronidazole].

    PubMed

    Kida, Dorota; Pluta, Janusz

    2011-01-01

    The carried out studies allowed to propose composition of stomatological dressing makes opportunity to ensure preferable physiochemicals features for dosage forms. According to results formulations contain 1.5% Carbopol 971P, 0.13% methylocelullose and various quantity of glycerol, 1,2-propylene glycol and polyethylene glycol 400 were prepared. To compare formulation consists of only polymers dispersion (Carbopol 971P and methylocelullose) was prepared. Next to produced compound triethanoloamine to pH range 5.5-6.5 and 1% metronidazole added. Kinetics test of metronidazole release was performed in vitro using Hanson's cells and semipermable membrane. The quantity of the release metronidazole was determined by spectrophotometric method. Gel consists of 98% polymers dyspersion with 2% glycerol characterized by the largest pharmaceutical availability. The addition of 2% PEG 400 resulted in the decrease of the percentage of released substance in comparison to formulation without hydrophylisers. Metronidazole releasing was more efficient for dressings with 2% glycerol as well propylene glycol. For preparations contains glycerol (2 and 5%) as well propylene glycol as adiuvants, it was found that gels prepared on Carbopol 971P and methylocelullose revealed higher pharmaceutical availability than analogical dressings prepared with only one polymer base.

  20. Metronidazole Injection

    MedlinePlus

    ... gynecologic, and abdominal (stomach area) infections caused by bacteria. It is also used to treat endocarditis (infection ... of medications called antibacterials. It works by killing bacteria and protozoa that cause infection.Antibiotics such as ...

  1. A meta-analysis of metronidazole and vancomycin for the treatment of Clostridium difficile infection, stratified by disease severity.

    PubMed

    Di, Xiuzhen; Bai, Nan; Zhang, Xin; Liu, Bin; Ni, Wentao; Wang, Jin; Wang, Kai; Liang, Beibei; Liu, Youning; Wang, Rui

    2015-01-01

    The aim of this meta-analysis was to compare the efficacy of metronidazole and vancomycin for the treatment of Clostridium difficile infection, especially to investigate which agent was superior for treating either mild or severe C. difficile infection. A meta-analysis of randomized controlled trials and cohort studies identified in Pubmed, Embase, and the Cochrane Library was conducted. Four randomized controlled trials and two cohort studies involving 1218 patients were included in this meta-analysis. Metronidazole was inferior to vancomycin for treating C. difficile infection in terms of both initial clinical cure rates (risk ratio, RR=0.91, 95% confidence interval, CI=0.84-0.98, p=0.02) and sustained cure rates (RR=0.88, 95% CI=0.82-0.96, p=0.003). For mild C. difficile infection, the efficacy of metronidazole and vancomycin resulted in similar clinical cure rates (RR=0.94, 95% CI=0.84-1.04, p=0.21) and sustained cure rates (RR=0.93, 95% CI=0.83-1.05, p=0.26). For severe C. difficile infection the efficacy of vancomycin was superior to metronidazole in terms of clinical cure rates (RR=0.81, 95% CI=0.69-0.95, p=0.009), whereas sustained cure rates were similar (RR=0.86, 95% CI=0.72-1.02, p=0.08). Regarding microbiological cure metronidazole therapy was as effective as vancomycin therapy (RR=0.88, 95% CI=0.64-1.21, p=0.43). Recurrence rates with metronidazole and vancomycin for both mild C. difficile infection (RR=0.95, 95% CI=0.56-1.60, p=0.85) and severe C. difficile infection (RR=1.27, 95% CI=0.85-1.91, p=0.25) were not different. Likewise, no difference in all-cause mortality was found as well (RR=0.87, 95% CI=0.56-1.35, p=0.53). In conclusion, vancomycin provides improved initial clinical and sustained cure rates in patients with C. difficile infection compared with metronidazole, especially in patients with severe C. difficile infection. In view of these data, vancomycin may be considered first line therapy for severe C. difficile infection. Copyright

  2. Comparison of oral and vaginal metronidazole for treatment of bacterial vaginosis in pregnancy: impact on fastidious bacteria.

    PubMed

    Mitchell, Caroline M; Hitti, Jane E; Agnew, Kathy J; Fredricks, David N

    2009-06-10

    Bacterial vaginosis (BV) is a common condition that is associated with preterm birth and acquisition of complex communities of vaginal bacteria that include several fastidious species. Treatment of BV in pregnancy has mixed effects on the risk of preterm delivery, which some hypothesize is due to variable antibiotic efficacy for the fastidious bacteria. Both oral and intravaginal metronidazole can be used to treat bacterial vaginosis in pregnancy, but little is known about the impact of different routes of antibiotic administration on concentrations of fastidious vaginal bacteria. This was a sub-study of a larger randomized trial of oral versus vagin